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March, 19 43 NEWNES PRACTICAL MECHANICS 181

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182 NEWNES PRACTICAL MECHANICS March, 1943

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Owing to the paper shortage " The Cyclist," "Practical Motorist," and "Home Movies " aretemporarily incorporated.

Editor F. J. CAMM

VCL. X. MARCH, 1943 No. 114

OfficeTHE office worker does not always feel

that he is a part of the war effort, yethe is just as essential as the machine

operative, the designer, and the draughtsman.His job is to see that the factory workssmoothly, that documents are availablewithout waste of time, that tools are returnedto the stores, and the factory records generallyaccurately kept, and accurately analysed.His job is to present in a visual form a cross-section of the position of the factory at agiven moment, sd that bottlenecks can bespotted and remedial measures adopted.There are so many office systems, however,that a skilled clerical assistant used to onesystem finds when he takes on a new jobelsewhere that he has to start again, becausemost factories adopt their own system.Some of these systems are evolved by theaccountants.

,Numerous books...and articles have beenwritten on the subject of system, and theorganisation of office routine, but no one hasyet standardised a system which would beacceptable to all factories. Engineers havestandardised evetything but routine. I amglad, therefore, to note that the BritishStandards Institution are tackling theproblem, in' conjunction with the Ministry ofProduction. They have published a bookletwhich deals with the work of the Institution,and with various aspects of the ways in whichfactory offices can assist production. Consider-able importance is ascribed to the efficientorganisation of the offices and factoriesengaged on war prodtiction. The vast changein the volume and nature of the country'sindustrial production during the war hasbrought with it many problems. One whichbears heavily upon factory output is that ofobtaining from the clerical administration thegreatest possible aid to factory production, aproblem rendered more acute by the depletingof staff as well as by the increased workoccasioned by the filling in of forms anddocuments necessary to meet the requirementsof a number of Government departments.

RecommendationsIn view of its close association with industry,

the British Standards Institution was requestedto inquire into this matter, although theproblems involved were somewhat outside itsusual sphere. Accordingly, the Institutionheld a conference, at which it was decided toset up a committee which would makerecommendations on the most appropiateprocedure, designed to promote simplificationand greater efficiency in, the clericalside of works production and organisa-tion. The committee, through expert sub-committees, has, in course of preparation, anumber of booklets ; the following are

Aid to theBY THE EDITOR

Factoryamong the subjects which will be dealt within them : Factory production control methods,costing systems, industrial purchasing, store,keeping, receiving, despatching, invoicing,pay roll methods, and office practice andorganisation.

The principles set out in these booklets willbe familiar to large and well -organised firms,bUt the majority of the works in this countryare small units, and it is to assist these inparticular that the booklets ate being issued.Their object is to bring to the attention ofthose engaged in the management of productiveengineering enterprises, those methods whichare generally considered to be the mostefficient in dealing with the clerical side ofworks production and organisation.

PrinciplesIt might at first appear difficult to make

proposals which would be equally applicableto large and small establishments, but theprinciples involved are the same. Principlesare therefore defined and a choice of practicesgiven to suit varying needs. The object istowards simplification of the work involved.It will be demonstrated how the introductionof an efficient system tends to remove obstaclesto smooth and efficient working. Theessence of efficient manufacture is orderlyadministration, which has given rise to thescience of production control. Muddle isthe fifth column in the factory. Experiencehas shown that inadequate planning andorganisation in factories results in delaying,confusion and consequent inability to deliverby the promised dates. Other results spring-ing from the same cause are the overloading ofsome machines while others stand idle, aswell as the sudden discovery of shortage ofstock. Ways will be suggested of eliminatingthe overlapping of effort, and inaccuraciesand inadequacies of clerical records.

In regard to costing it is recognised that nouniform system would be suitable for allfactories. Identical principles should, how-ever, be generally applicable. It is essentialin every efficient factory that the rawmaterials required shall be available at theright time, in the right quantity and quality.Methods will be suggested indicating howpractices recommended for small firms maybe amplified for adoption by larger ones.In any well -managed factory it is essentialto ensure that proper provision is made forthe receipt of goods ordered as well as forthe prompt payment for them. When goodshave been produced and orders fulfilled theyshould be promptly despatched and invoiced,and the whole transaction from order todelivery completed ' as expeditiously aspossible.

The information essential to put intooperation any system of production controlshould be prepared in a form which makescomparison easy and rectification compara-tively simple. For example, recommendationsare to be made for the recording of machineutilisation, to show how many hours eachmachine is kept working, how many hoursit is idle, and the number of hours lostthrough breakdown. This and similar essen-tial information, and the method in which itcan be most effectively recorded, are to bedisclosed.

Of course, the most perfect system in theworld breaks down if it is operated by un-'skilled or lazy office staff. Whatever systemis introduced should, therefore, be simple,so that it requires little skill, and may beoperated by the unskilled office staff which isnow replacing the skilled, and will go onreplacing it until the war is over. We mustavoid system for the sake of system. Somefirms have large staffs employed in keepingthe system going-filling in unnecessaryforms and compiling unwanted statistics.Some of these so-called " office systems " arecostly to buy.

Pay RollsThe wages of the whole labour force of

the country have to be paid every week,promptly and accurately. The method ofpreparing pay rolls varies according to thesize of the factory, and the degree to whichoffice machinery is installed. One of thefactors which complicates the preparation ofa pay roll is the large number of deductionswhich have to be made from wages everyweek. On an average about 14 deductions,compulsory or voluntary, are made fromindustrial workers' wages every week. Inone large undertaking it is known that thereare 73 possible deductions from gross wages.Many companies engaged in engineeringproduction appreciate the importance of theclerical sections of their organisations. Theyare not regarded as necessary evils or dis-pensable necessities. As a result methodshave been developed which are likely toproduce the best results from the point ofview of economy in labour and the readyavailability of required information. It issuggested that in every factory there shouldbe, depending on its size, either an individualor a committee whose duty it would be tostudy the whole subject of organisation andmethods in the light of the information whichwill be gathered from these booklets. Thebooklets will he on sale at 6d. each, post free.Remittances should not be sent until theirpublication is announced, but the addressof the British Standards Institution is 28,Victoria Street, London,



A Synchronous

Fig. L-The original motor compared in sizewith a penny.

THE clock motor forming the subject ofthis article was originated through thedesire to build a unit suitable for

operation direct from the mains, and com-parable with the commercial article inaccuracy of timekeeping, dimensions, andcurrent consumption, but at the same timecapable of being constructed with a few simpletools such as are found in the kit of any handy-man, plus a reasonable amount of skill andpatience.

The motor is described exactly as built,although it is not suggested that the designor method of making are perfect or most suitedin every detail to " home pr.oduction," but nodoubt the reader attempting construction ofthe motor will effect such modifications as willtend to simplify construction, according to theequipment at his disposal.

An important difference between clocks ofthe synchronous motor type and those of thespring -driven type, which is of distinctadvantage, lies in the fact that in the latterthe clock drives the regulating mechanism,i.e., pendulum or balance wheel, whereas inthe former the regulating mechanism (in thiscase the motor) drives the clock. The spring -driven clock has the motive force-capableof exerting considerable torque-applied atthe beginning, i.e., the " slow " end of thegear train. The resultant motion is then gearedup and regulated to the correct speed by anescapement mechanism of one form or anotherat the " fast " end of the train. Due to thehigh ratio between the ends of the train thetorque available for operating the escapementis extremely small, and in order to avoid errorsin the timekeeping of the clock it is essentialthat the escapement be constructed with ahigh degree of precision. Fortunately, thesynchronous motor type of clock is free fromthis advantage as the regulator, i.e., the motor,supplies its own driving torque, the powernecessary for this being available in virtuallyunlimited quantities and hence accuracy ofworkmanship is not such a vital factor.

Small TorqueActually, due to the high ratio of the gear

train, the torque required from the motor isextremely minute and may be ignored, themain load consisting of its own friction. Theone accurate feature required is a trulyuniform speed of rotation, which in the typeof motor described, is fixed by the design andhappily is not dependent on the precisionwith .which it is constructed; in fact, a sur-prising amount of latitude is permissiblewithout any marked ill -effect on the operationof the motor. In electric clocks of this type thereally accurate part of the job is, of course,supplied ready for use by the electricity under-taking in the shape of time -controlled alternat-ing current mains (the clock motor merely

Electric. Clock MotorConstruction- Details of an Interesting Clock Conversion

By L. F. ROWE

serving as a means of keepingthe clock in step with thesupply alternators), a fact forwhich the home mechanic, lackingthe facilities to produce precis-ion wo,k, may be duly grateful.

Fig. 2.-Showing how the motor is mounted in the clock case.

The original motor is shown in Fig. r, whichillustrates the diminutive size of the unit.Although it was made entirely without the useof a lathe its performance came fully up toexpectations, the speed being absolutely con-stant and the current consumption, on 230 -volt mains, less than half a watt. The dimen-sions were kept as small as practicable so thatit could be conveniently accommodated in thecase of an existing clock of the spring -driventype, the " works " of which had ceased tofunction with any degree of reliability. Thiswas accomplished simply by removing thespring and its associated gears and pinions,together with the balance wheel and escape-ment mechanism, leaving a continuous trainof wheels between the hands and the wheelimmediately preceding the escapement wheel.The escapement wheel having specially shapedteeth is useless as a gear wheel. It is, of course,essential to have the correct ratio betweenthe rotor of the driving unit and the spindledriving the hands, and it was found necessaryto increase the ratio of the existing train bythe addition of two further stages of reduction.

The motor was moented on a simple bracketscrewed to the side of the clock frame, in sucha position that correct meshing was obtainedbetween the pinion on the rotor spindle andthe last wheel of the train. The arrangementis shown in Fig. 2, which illustration alsoshows the additional gearing which is mountedbetween brass extension brackets screwed tothe existing side plates. The clock thus con-verted keeps perfect time and is highlysatisfactory. The pinions carrying the hands

are driven via the usual friction device, anddue to the high torque (as compared withthat normally available to an escapement)and the higher gear ratio, the clock now pos-sesses the advantage that the position of thehands can be adjusted either forwards or back --

wards by the normal adjustingknob without stopping the motor.This feature is of great assistancewhen setting ,the clock to a timesignal. For the benefit of readerswishing to fit the unit to an exist-ing clock on the lines describedabove, details are given later con-cerning the selection of suitablewheels for the additional gearing.

Principle of OperationFor those who are not fam-

iliar with the principle on whichthis type of motor works thismay be briefly explained asfollows. The motor is of the"phonic wheel" type, one of theearliest and most simple types ofsynchronous motor devised. Itconsists of a toothed soft irondisc, or rotor, free to rotatebetween soft iron pole pieces,each having teeth similar in sizeand spacing to those on the rotor.The pole pieces form part of thestationary magnetic circuit, orstator, at the centre of which is a

the necessaryenergy, On energising the coilfrom an alternating current sup-ply, an alternating magnetic flux isset up in the iron circuit, and flowsfrom one pole to the other via therotor, reversing its direction insympathy with the frequency ofthe supply. If at the instant of

'witching on the current the teeth of the rotorand pole pieces are not exactly opposite,the magnetic flux, by virtue of the fact thatit always takes the path of least resistance,decreases the air gap between poles and rotorby pulling the teeth into line.

A torque is thus set up in the rotor which,however, is reduced to zero immediately thetwo sets exactly coincide, since any furthermovement of the rotor beyond this pointwould, of course, increase the air gap, result-ing in a torque being set up in the oppositedirection, In consequence, once the rotor hasbeen pulled into line with the pole teeth it isretained in this position. If, however, therotor is caused to revolve by an externallyapplied torque, at such a speed that betweeneach of the magnetic impulses caused by thealternating current the rotor is able to moveexactly one tooth forward, it will continue torevolve at this speed when the externallyapplied torque is removed. This is due to the

SiA.P.,2tes of Gear Train

First Wheel ofAdditional Stages -4 --Last Wheel of

Existing Train

Increased did. Arbour shortened andfitted with Bracketof Wheel Bearing (Shown dotted)

Fig. 3, Modification to gear train.


March, 1943. NEWNES PRACTICAL MECHANICS

fact that at this particular speed, i.e., thesynchronous speed, the period when the rotorteeth are midway between the pole teethcoincides with the period when the magneticflux is zero and thus no torque is exerted onthe rotor at this point and its inertia is allowedto carry it towards the next tooth. As the mid -position is passed and the next tooth isapproached the magnetic flux is growing instrength, the resulting torque impartingfurther energy to the rotor. The flux strengthreaches its maximum when the teeth are againin line, and as it begins to diminish the rotoris again carried forward by its inertia to thenext midway position, the process then beingrepeated. This cycle of events is continued solong as the alternating current supply is con-nected to the coil and affects simultaneouslyas many teeth on the rotor as there are on thepole pieces. Thus the rotor continues torevolve in step with the magnetic impulsesat the rate of one tooth per impulse.

A few moments' considerationwill show that it is impossiblefor the rotor to revolve at anyother than the synchronousspeed. If the speed were lessthan synchronous the magneticimpulse would be increasing instrength before the rotor teethhad reached the midway posi-tion and there would be atendency for them to beattracted back to the pole teeththey had just left, i.e., thetorque would act in the reversedirection. This effect increaseswith each impulse, as the lag ofthe rotor behind the impulsesis cumulative and within thespace of a few impulses thereverse torque is sufficient tostop the rotor. Similarly, if thespeed is greater than syn-chronous the rotor teeth pass thepole teeth before the magneticimpulse attains its maximumstrength and are attracted back,setting up a reverse torque andeventually stopping the rotoras before. Theoretically itshould be possible for the rotorto revolve at a multiple of the synchronousspeed, but this can only occur if the field issufficiently intense to give the necessarytorque, and can be avoided by the use of asuitable energising coil.

Speed of RotorFrom the foregoing it will be appreciated

that the synchronous speed in revolutions persecond is equal to the number of magneticimpulses per second divided by the number ofteeth on the rotor. The number of teeth onthe pole pieces does not affect the speed. Onecomplete cycle in an alternating currentsystem has two points of maximum value, one

1

1

1

°Stalloy-Lams screwedto underside of Template

185

positive and one negative, separated by a pointof zero value. Since the rotor and pole piecesare of soft iron, and not polarised, thenegative and positive maximums have thesame effect and attraction between poles androtor occurs in both instances, thus givingtwo magnetic impulses per cycle. The rotorof the motor described has 25 teeth, and,therefore, when connected to a supply havinga frequency of 5o cycles (too impulses) persecond has a synchronous speed of fourrevolutions per second. This speed waschosen, firstly, because it is convenient forworking in the gear ratios, and, secondly,because 25 teeth was the greatest number thatit was practicable to accommodate on therotor without increasing its dimensionsbeyond the proportions required.

From the principle of its operation it willbe. appreciated that a motor of this type willrun.equally well in either direction, dependingon the direction of the initial starting torque.

-I

--j

2 Holes 65A ClearOne on Assembly

YOKE

"I*

6 Lams=aeProxjt,

25 HolesDrill /Vo.74These holesro be equallyspaced andmarked offfrom 4"PCD

5 HolesDrill No. 74

(For Rivets)

Drill to suitArbour(Tight fit.)

Brass Plateapprox 42"sq.

Fig. 5.-Details of the rotor- drilling template.

It is therefore essential to see that it is alwaysstarted in the right direction, and this can beeffected by a simple starting mechanismdescribed later..

The motor is not self-starting, which isactually an advantage, as it prevents anypossibility of the clock restarting itself after abreak in the supply and indicating incorrecttime.

Arranging the GearingObviously, no definite instructions can be

given regarding the fitting of additionalgearing, since this will vary in every case,depending on the type and size of clock, and

One onAssembly

POLE PIECES Meth spaced to suitRotor (see text)

Off As Above -. 6 Lams.= a

Off Opposite Hand:F opprox

(Lams arranged as shown)

Fig. 6.-Method of forming yoke and pole pieces.

e:"Stalloy" Laminations-,-approx

di

1-

25 Teeth equally spacedWidth of teeth = Width of gap.

Fig. 4.-.Front and side views of the rotor.

the wheels and pinions available for formingthe additional reduction stages. The' final

details are, therefore, left to theingenuity of the individual, butthe following notes may provehelpful in this direction. Oncehaving fixed the speed of themotor it is a simple matter tofind the gear ratio required betweenthe rotor and the pinion of theminute hand (if an existing clocktrain is being used the I2:Iratio between the minute and hourhands will already be provided).Since the minute hand makesone revolution per hour the ratiomust be equal to the number ofrevolutions per hour of the rotor,and in the case of a motor havinga speed of four revolutions persecond will be 14,400:1.The" going " train of a normal clockhas a ratio considerably less thanthis, and it will be; necessary toincrease it by the addition offurther stages of reduction gearing.

Before it can be decided whatincrease in ratio is required it is,of course, necessary to determinethe exact ratio of the existing trainafter removing the escapementwheel. The only safe methocP

of doing this to ensure accuracy is to carefullycount the number of teeth on each wheel andpinion throughout the train, carefully notingwhich are drivers and which are driven, andwork out the ratio from the figures obtained.It must be remembered that an error of onlyone tooth in the counting will cause the clockto steadily gain or lose according to thedirection of the error. When the existing ratiois known the number and ratios of the addi-tional steps can be arranged. These will natur-ally depend on the size and types of wheelsand pinions available, although generally twoor three stages will be sufficient, providedthere is room to accommodate fairly largewheels. It is necessary to provide a pinionon the rotor spindle, and this must be takeninto account when working out the ratios.

In the usual clock train the diameter of thewheels decreases with each successive stage,and due to this it may be found that the firstwheel of the additional stages has to be ofsuch small diameter (to obtain clearancebetween it and the arbor of the last wheel ofthe existing train) that it is impossible toobtain the final ratio required.

This difficulty may be overcome by modify-ing the last stage of the existing train, as shownin Fig. 3. The arbor is shortened and fittedwith a new bearing in the form of a bracketattached to the side frarpe in a convenientposition. This allows the next wheel to overlap,thus permitting a considerable increase indiameter. Almost any clock type of gearwheelsare suitable for making up the extra stages,and those used in the clock described wereobtained from the 'counting train of an


.186 NEWNES PRACTICAL MECHANICS March, 1943electricity meter of the house service pattern,the complete train being bought for a few -

coppers from a junk stall. These were idealfor the job, giving up to to : i ratios andpossessing the advantage of having bossesfitted with grubscrews, making for easyassembly and convenient adjustment. If thewheels used are not suitable for meshingwith the last wheel of the existing train, thelatter can be replaced by a wheel of similartype to those used for the added stages, theexisting arbor and pinion being retained.To ensure smooth running the wheel andpinion Teeth should mesh by an amount equalto one-third of their depth. If the extensionplates forming the bearings for the additionalarbors are made in one piece accuratedrilling be required to obtain correct

ik"

h

To suitRotor Pivot

.5 B A Clear I

FRONT BEARING

/6

Tap

REAR

firmly riveted together before drilling orcutting to -shape. Due to the hard scale on thesurface of the laminations it is difficult tomark out or drill them accurately, and adrilling template was made from a piece ofbrass sheet large enough to allow a circle of4in. diameter to be described centrally on oneside. A second circle of in. diameter wasstruck from the same centre. The circum-ference of the larger circle was divided into25 equal parts to give the spacing requiredfor the rotor teeth. This was effected bystepping round a pair of dividers, adjustingthe span by trial and error until the correctdistance was found. it was first divided intofive equal sections, each section then beingdivided again into file equal parts. A straight-edge was then carefully adjusted, to line up

with the centre of thecircle, and each of the25 points in turn, a linebeing carefully scribedwhere the straightedgeintersected the circum-ference of the lin.diameter circle.

The six pieces of stalloywere cut into approxi-mately r squares andscrewed to the undersideof the template (see Fig.5) and five holes drilledwith a No. 74 drill forrivets, one on each of thefive main dividing lines ona- tin. diameter circle;The

laminations werethen removed from thetemplate and riveted to-gether with iron wire, theoutside laminations being

slightly countersunk and the rivets filed flush.The assembly was again screwed to the tem-plate and the 25 holes drilled for the teeth,again using a No. 74 drill.' The central holewas also drilled at this stage, the diameterbeing -a tight fit for the arbor. It was foundessential to rivet -up the laminations beforedrilling these holes as a small relativeMovement between the laminations is boundto occur when riveting; with the result thatif the holes are drilled first they take upan angular direction with respect to the faceof the assembled laminations. This is par-ticularly serious in the case of the centralhole, as it causes the rotor to run badly outof truth with the arbor.- After removing from the template thesurplus material was trimmed away until the'diameter was gin., thus leaving a ring of" half -holes " t h espaces between whichform the teeth of therotor. These weretrimmed square bymeans of a thin file.The rotor was nextfiled until it was roundand true. For this -purpose it was fittedwith a spindle andtemporarily mountedon -two bearingbrackets, a stop ad-justable to lie close tothe edge being ar-ranged to detect- the"high spots " as wasrotated. These, v'eresuccessively rem,vedby filing until therotor ran true. Thisis a rathe.1 tediousprocess, but time spenton this part of the jobis amply repaid by theincreased efficiency ofthe completed motor.

Other dimensionsas FrontBearing

B.A.A.

BEA RING

Fig. 7.-Front and rear bearings.

meshing. This can be avoided by the use ofindependent bearings for each arbor, thesebeing provided with ample clearance in thefixing holes to permit of individual adjustment.

In Fig. 2 the added wheels and hearingplates can be plainly seen. In this case onlytwo stages were added, although, in effect, athird stage is provided by the reductionbetween the pinion on the rotor spindle andthe last wheel of the extended train.

Should the ratio required to be provided bythe additional gearing work out to some oddvalue which is found difficult, or evenimpossible, to obtain with the -wheels andpinions available, it should be borne in mindthat this may possibly be overcome by arrang-ing the number of teeth in the'rotor to give aspeed which will suit the gearing, and it is aswell to consider this in the light of the gearsavailable before deciding on the number ofteeth on the rotor. As regards calculations,the energising current can be considered as adriving wheel having a hundred teeth (on a50 -cycle supply), and the rotor as a drivenwheel, the number of teeth being arranged togive the ratio required.

The possibility of using worm drives shouldnot be ruled out, since these give a high,reduction ratio, and the worms can be easilymade by winding wire round an arbor. Thediameter 'of the wire and spacing of the turnsbeing arranged to suit the teeth of the wheelwhich it drives,

Apart from being suitable for embodimentin the frame of an existing clock, the unit can,of course, be used as the basis of an entirelynew clock, in which case many of the snagsmentioned above would not arise, since theconstructor, having a free hand, wouldnaturally build the clock to suit the gearing.

The RotorThis, being the heart of the job, was the first

part to receive attention. It was made ofStalloy " soft iron laminations obtained

from an old transformer. The dimensions aregiven in Fig. 4. "Six laminations make up thethickness of approximately these being

The rotor was fitted with an arbor (fromthe meter-.pounting train mentioned earlieron), which had to be shortened to suit themotor and re -shouldered. Although it hardlyseems a practicable method of doing it, thenew shoulder was formed by filing, a smallfretwork rile being used for the job. A squarewas first formed by removing an equal amountfrom each side, this in turn being formed intoan octagon by removing the corners. Succes-sive series of corners were then removeduntil the arbor again assumed a circularshape; fatally it was polished with fine emeryand burnished whilst held in a revolving drillchuck. Strange to say, this ran almost deadtrue.

A simpler arrangement would be to leavethe arbor unshouldered and drill the bearingbracket to suit the full diameter. In this caseit would be necessary to provide a stop toprevent lateral movement of the arbor,unless the bearing bracket is drilled witha blind hole. An objection to using thefull diameter of the arbor is that it con-siderably increases the friction unless thediameter is very small. On the arbor ofthe rotor was also fitted a small pinion (fromthe same source) to suit the gear train, and asmall brass disc about kin. diameter bythick. This latter item is to give a flywheeleffect by increasing the inertia, thus assistingin starting and giving smoother running.

Pole Pieces and YokeDetails of these are given in Fig. 6 and, like

the rotor, they consist of six stalloy lamina-tions riveted together. It will be noted thatthe ends are arranged to interleave. This,however, is not essential, although it makesa neater job when assembled. If preferred,both yoke and pole pieces can be made withsolid ends and overlapped without affectinganything but the appearance. If they areinterleaved it is, of course, necessary to cutback alternate laminations before riveting upand also to arrange them to be right- and left-handed, as shown in the sketch.

It.should be noted that as the pole piecesare exactly opposite when assembled, and therotor has an odd number of teeth, there willhave to be a difference in the relative positionof the teeth on each pole piece equal to halfthe width of a tooth. To ensure that thecorrect position was obtained, the pole pieceswere finished off with the exception of theteeth, which were marked off from the rotorwhen assembled, the rotor being movedalong its arbor to allow it to overlap thepole pieces. The teeth of the pole pieceswere then careful y filed to shape anti re -

Flanges to begood fit overTube and Tape

74:7era1111=

Tube 45x32" Inside(Easy fit on yoke)Tube wall = 64'

Mains Coil 47L.V. Coil Z"

27"

H32

Method of securingflanges with Tape

Fig. 8.-Details of bobbin construction.



assembled, the rotor being moved back intoits correct position between them. Finaltouching up of the pole pieces with a fileenabled quite a small air -gap to be obtainedbetween them and the rotor. To allow forany irregularities the air -gap was madeadjustable by allowing ample clearahce roundthe fixing screws of the bearing brackets,where they passed through the pole pieces.Bearing Brackets

These are shown in -Fig. 7, and are madefrom brass strip. Care should be taken indrilling the holes for the arbor : these shouldbe a good bearing fit and if possible -finishedwith a watchmaker's brooch. If this is notavailable, however, a piece of wire and a littlefine grinding paste may be used to obtain therequired fit. The holes should be slightlycountersunk each side for retaining lubricatingpil.

The BobbinThis was made from scraps of sheet.bakelite,

the flanges being "/:,. in. thick and the tube1/641n. thick (see gig. 8). The tube wasformed by bending up from sheet, the overlapbeing secured with seccotine, k is necessaryto heat the bakelite before it can be bent.This was effected by means of a heated pieceof hacksaw blade, the edge being applied tothe bakelite along the line of bend. TheGlade should not be too hot ; just short ofteed heat is sufficient, as if hotter than this the

bakelite will blister. 'Alternatively the tubecan be formed round a strip of metal havingthe same section as the yoke. This ensuresobtaining the right shape and size, but dueto the greater area in contact is more likelyto blister the bakelite unless carefully handled.

The flanges were secured to the tube bytwo strips of black silk tape glued to thesides of the tube, the ends being passedthrough the aperture, round the flanges andback on to the tube, as shown in Fig. 8. Theapertures in the flanges were made a snugfit over the tube and tape, the whole beingfirmly cemented with seccotine, making astrong, rigid assembly. The shiny surface ofthe bakelite was removed with glass-paperat all contact surfaces to provide a key forthe cement. Fig. 8 shows alternative smallerdimensions for the flanges, which are suitablefor a low -voltage coil.

Winding the CoilThe bobbin was wound to capacity with

48 S.W.G. S.C.C. copper wire, approximately0.4 oz. being used, giving about to,000 turns,and having a resistance of 12,60o ohms. Thisfigure is the D.C. resistance as measured ona Wheatstone Bridge, and not the A.C.resistance or impedance. The task of windinga coil of such small gauge wire by hand was aformidable one and required the expenditureof a considerable amount of time and patience.It was first attempted by mounting the bobbin

on a Suitable spigot held in the chuck of awheel brace supported in a vice. Whilst thegearing enabled a high winding speed to beobtained, it was inclined to be " snatchy " anddid not give the sensitive control requiredfor the fine wire, which is only approximately

thousandth of an inch in diameter. Asimple winder was therefore made up inwhich the bobbin was rotated direct, bymeans of a cranked shaft. This gave a bettercontrol over the tensioning and guiding ofthe wire and was quite satisfactory.

Before commencing the winding, the endof the wire was soldered to about t5in. ofstouter wire of about 20 S.W.G. to form aconnection lead. This lead was taken twiceround the bobbin to anchor it, the free lengthbeing spiralled by winding round a fin.diameter rod and tied to the spindle of thewinder to keep it out of the way whilst wind-ing. Where this lead runs from the tube ofthe bobbin to the edge of the flange it lies inclose contact with the end 'turns of each layerof the winding, and in order to prevent anypossibility of it shorting out any of the layersit was covered with a piece of insulating tape.

It is, of course, -impossible to wind such 'afine wire in even layers by this method, an 1no attempt was made to do so, although thewire was guided so as to fill the bobbinevenly.: the main object being to get on asmany turns as possible.

(To be continued)

Piston RinAsNotes on Their Production By P. BOUSFIELD

great importance of the piston ringcannot be overestimated.

Let us first of all briefly survey thishighly skilled product in its finished form tofind a few of the requirements which must' beembodied in its manufacture.

Ordinary rings are called " compression "rings, because it is their essential function tomake the piston-of which they form anessential component-a really close fit in itsliner, and to prevent blow -by of the gases.The ring is thus an essential factor in ensuringthe efficiency of the piston. Then again thereis the question of the ring having an effectivejoint, and of the working face or " rubbingsurface " of each ring.

These are just a few factors which have tobe borne in mind when an engineer places anorder for rings.

For example, the order will state thediameter, the working width and the thickness(the three main dimensions). On the top ofthis information it would be stated what typeof joint is required-e.g., butt, angle or lap.Besides this it should also be mentionedwhether the rings are required to havesmoothed off edges (radiused)-3therwise theywill probably be left as sharp as razors.

ProductionThere are three methods of producing

piston rings-each one is a casting process,but the process varies. The chief process, andthe one which we shall deal with in this article,is the " pot " casting:

It should, however, be mentioned in passingthat there are " spun ' or centrifugal castings-where the metal is spun into a homogeneoushollow cylindrical mass of molten metal.Then there are single castings, although thewriter believes the latter relates chiefly toproduction in Scandinavia.

Pot CastingsThe pot is a cylindrically shaped mass of

molten cast iron. This arises from metal

poured from the ladle into a mould. Theresulting " pot " is removed while stillintensely hot and is left to cool.

After cooling, a rough cylinder remainsfor many further operations ; it certainlylooks very little like the precision productwhich may be ready some hours later if for an

urgent contract.The pot casting is a rough method, " as

cast " jobs are never to " finished " sizes ;on the contrary they are very much oversize.The pot has still to have the rings parted offfrom it, and then they have to be split for thering joint. There is a great deal of machiningthen to be carried out, and accurate " limits "have to be adhered to.

The inner face of the ring has to be skil-fully hammered to give the correct outwardpressure against the cylinder wall. Thenthere is the inspection department, and thisis where rejections have often to be made onaccount of what many of us think of asnegligible inaccuracies.

The inspection of rings, and the highrequirements of that department go toprove whether the firm making the rings arereally high-class or not. It is absolutely notworth while to pass a ring which does notconform to the specified " limits," nor musta ring of poor analysis leave the works. .

Analysis of the MaterialThe foundry has a small laboratory attached,

and this laboratory has often the custody andknowledge of the closely guarded secret ofthe " melt." Practically every firm of reputehas such a special formula stating closely con-trolled quantities of the different elementspresent in the ring.

Foundry FaultsThere are, of course, various reasons out-

side of the control of the laboratory whyrings are often' rejected at the " pot "stage.There may, for example, be " slag " inclusions.The " slag "-which means impurities present

in the melt-which rises to the head of thecasting. Or there may be sand inclusionswhich arise usually through use of the in-correct sand-or due to poor moulding.

In one hundred and one ways the accom-plishment of a first-class ring is an achieve-ment only possible by the greatest care atevery stage and thorough soecialisation ; and

here are sotne of the reasons why a ring mayfail in service even after it has been passedas satisfactory at the works.

t. It may not be of material which givessufficient resistance to wear.

2. It may not be machined accuratelyenough.

3. It may not have been assembled correctlyon the piston.

4. The clearance may not have been cor-rectly ascertained, in which event the ringthough finished to stipulated sizes, maynot be the required fit in the piston groove.

In connection with this last-named point,the vertical clearance in the ring groove maybe too great, causing the ring to hathmer,and wear will increase considerably. Onthe other hand the clearance must not be to)small or the ring will become solid with thepiston, and its function will at once be lost.

Restricted RingsThere are on the market various rings

known as restricted rings, and as the namesuggests the movement of the ring in the grooveis controlled. Most of them are elaborateand hence are somewhat costly to manufacture,but it is known that a restricted ring has oftencome to the rescue of a job where there hasbeen trouble with plain rings.

To sum up, it should be realised thatmaking piston rings is a job for a specialistfirm, and firms who make rings often makelittle else. The manufacture of rings on alarge scale is shared 'among comparativelyfew firms, most of which are exceedingly wellknown, and have the highest standards ofquality to their name.



DOTS and dashes were unknown in earlysystems of electrical telegraphy. AndMr. Morse did not-as many people

imagine-invent, or rather, discover thephenomena.

Experimenters began to get busy in 1727,when Stephen Gray and Wheeler discoveredthat frictional electricity could be sent alonga conductor, and this was confirmed byBenjamin Franklin and William Watson in1747. Six years later," C.M.," a corre-spondent of the " Scots agazine," suggestedusing a telegraph with a wire for each letterof the alphabet, and the application of a currentto indicate the desired letters.

Prior to iSoo two men, Le Sage and Lo-mond, both tried out " C.M.'s " idea. Afterthat, Francisco Salva suggested that theelectric pile by Volta should be used for send-ing signals. Samuel Von Sommering tookadvantage of this, and constructed an instru-ment which controlled 36 lines. Each ofthese lines electrically conveyed a letter orsymbol. At the receiving end the wires, wereimmersed in water. Of course, 36 keysoperated the transmitter, and instead of dotsand dashes, the message was read by bubbleson the water ! Then, instead of the bubbles,they set light to alcohol. Later, an instrumentappeared on which the message was read 'byshocks. An operator would place his fingersand thumbs on terminals and verbally repeatsignals indicated by the shocks. All verycrude, but they give a good idea as to theefforts made by the pioneers.

When the eighteenth century was still inits teens, Sir Francis Ronalds produced amore practicable telegraph at Hammersmith.His apparatus consisted of something akinto the now old-fashioned " dolls -eye ' tele-phone switchboard, each " eye " moving byan electrical charge, and exposing a letter.

The Needle TelegraphThen somebody discovered the needle

telegraph. And the eighteenth century wasstill in its teens.

Ten years before Samuel Finlay Morse washeard of, inventors of different nationalitieshad experimented with the " needle " ap-paratus. One used 3o needles!

About 1835, however, the pace began to getvery hot. Many pieces of telegraphic apparatusconstituted features of exhibitions. Moncke,Cooke, Wheatstone, Gauss, Weber, Schilling,Highton, Henley, Allan, Bright, Neil, Stein -hen, were but a few of the number practicallyworking for perfection and recognition.

Readers of this journal already know thatin 1838 the first commercial telegraph instru-ment in this country worked between Eustonand Camden Town railway stations. Cookeand Wheatstone were responsible for theapparatus. This period appears to coincidewith the introduction of the inventor asso-ciated with dots and dashes:

Born at Charleston (Mass.) in 1791, SamuelFinlay Morse did not ever wish to become atelegraphist. What is'more, he never earnedhis living at that occupation. In fact, the manwhose name is now mentioned much morethan when Morse telegraphy held sway,belonged to a totally different school. Hepainted pictures. I mean, he actually was anartist in the true sense of the word. For in1813 Morse exhibited his first picture.

Morse often went to Europe to copy pic-tures, and during one of these voyages it issaid he contacted a Dr. Jackson on board aship named Sully. Dr. Jackson had recently

Who Invented Electrical Telegraphy?The Discoveries of the Early Experimenters

By W. T. LOWE

been present at a conference in Paris onelectro-magnet. Samuel Morse becameterested, and the conversation turned topossibility of utilising this phenomenatransmitting signals.

Electro-magnetic TelegraphyIn 1835 after various trials of electro-

chemical telegraphy, Morse made some ex -

thein -thefor

Sir Charles Wheatstone.

periments with electro-magnetic telegraphy.But the results were not very good. Two yearslater, however, he heard about Wheatstoneand Steinheil. Then an article appeared inAmerica declaring that the electrical telegraphhad been discovered, which announcementMorse didn't like. One of his two brotherswas editor Of an American journal, who statedthat Samuel Morse had been working on theidea for five years since he had conceived iton board Sully. Naturally, people wantedto see this marvellous electric telegraph ; andtwo of the visitors subsequently worked with

Morse on his experiments in September, 1837.They were the brothers Gale and Alfred Vail.It is recorded that their combined earlyefforts were again not -very satisfactory, butMorse insisted that he was the only inventorof the electric telegraph. He also affirmedthat all the other European systems were basedon different principles, and without exceptioninvented after his own.

Thirty-three years before Morse was born,Lomond tried to establish a system of tele-graphy with a pendulum. In 181o, the yearwhen Morse graduated at Yale University,the first galvanic telegraph was proved satis-factory, and actually worked.

It is a peculiar fact that the spot where thepresent world-wide trouble started should bethe birthplace of an international asset, forthis galvanic telegraph is said to have beeninvented in Munich !Schilling's Telegraph

Twelve years before Morse, Schilling con-structed an electro-magnetic telegraph whichwas exhibited at Bonn, and then at Heidel-berg and eventually introduced into Englandby Cooke. About six weeks previous to this,another telegraph, constructed on the sameprinciple as that of Schilling, worked over awire one and a quarter miles long.

Despite all this, and, based on undisputablerecords that Sir Charles Wheatstone himselfforestalled the American, the work of Morseis not to be despised.

Even Morse's first idea had nothing to dowith dots and dashes. It was, in fact, thecrude birth of the siphon -recorder or un-dulator used on cables and radio at the presentday. " V "-shaped signals were made on apaper tape, and one had to refer to a tele-graphic dictionary to translate them. In theexperimental stage, acoustic dots and dasheswere made by the sending operator passing apointer over metallic bars. Morse and hiscollaborators afterwards discovered that thiscould be done by depressing and releasing abar. That is how the Morse key on which yousend your signals to -day evolved.

By courtesy of the Postmaster -General.Wheatstone receiver, motor and train -1867.


March, 1943

When Wheatstone automatic telegraphywas - just emerging from its experimentalstage the press began to show keen interestin experiments at the G.P.O.

Many previous attempts were made toalleviate the tiring effect of hand workinghigh-speed morse for long periods. In 1846,Bain perforated dots and dashes on a paperribbon which, when passed through anapparatus, caused the signals to be reproducedby chemical means on another slip of paper.Experimentally, the system attained a speedof about 4,000 words an hour. But owing totechnical troubles (not at that period understood), in actual working it failed.

Did you know that a weaving loom is said tohave given Sir Charles Wheatstone thefundamental idea for his high-speed system ?Anyhow, by means of passing perforatedribbons through a transmitter, he dealt with8o words a minute in 1870. Eventually, theapparatus disposed of 450 words in the sametime. In fact, in experiment, the 600 markhad been reached by 1900.

In many instances identical newspaperitems had to be transmitted to different citiesand towns from the Central Telegraph Officein London. And this is where Wheatstoneshowed itself to another advantage. Theperforated slips could be used repeatedly, andpassed from one transmitter to anotheraccording to the destinations indicated.Moreover, as many as half a dozen stationswould be accommodated on one line, and thewhole able to receive the message simultane-ously. A slip could be seen running on whatwas known as the " Up Scotch " (Edinburgh,Glasgow, Dundee and Aberdeen circuit), andoften before it had run its course, the messagewould commence its electrical journey througha transmitter on another line to other stations.

To obtain attention of every station onthese lines the operator would call " CQ "and the distant stations, . according togeographical situation, would answer in turn,the answering first.But if the message was intended for only twoof the six stations on one line the telegraphistwould call them separately with the suffixsignal " YQ," indicating that another stationwould also be called.

Pneumatic PerforatorsAs pneumatic perforators could simultane-

ously produce eight paper ribbons containingthe same message, and as there were an averageof four stations on Wheatstone press wires,this meant that the same message would beconveyed to 32 places in the British Isles atidentical moments, at a moderate speed of150 -zoo words a minute.

In the first instance, these perforated slipscaused morse dots and dashes to appear on ablue paper tape running at the same speed asthe transmitter. It is on record that onemessage would sometimes consist of a mileof this morse slips containing 26,000 words.So that the receiving clerk and editors coulddeal with this volume more conveniently, themessage would he split up into sections. Eachsection was torn off the paper ribbon and givento a telegraphist to translate from the dots anddashes. As he (or she) completed the sectionit was sent out to the editor. Thus, part of acolumn, we are given to understand, wouldperhaps be in type before a speaker had saidhis last word-if the despatch consisted of aspeech.

Incoming press work at the C.T.O. largelyconsisted of racing reports. On the occasionof meetings special offices were set up on thecourses, and the most expert operators chosenand despatched to control the apparatus.(The same, of course, applied to someprovincial offices.)

In addition to race -meetings, other specialevents-such as speeches by M.P.s in theirconstituencies, cricket and football matches,gardening shows, visits of important person-

NEWNES PRACTICAL MECHANICS

ages, and other public attractions-requiredspecial Wheatstone telegraphic facilities.

Organisation and installation of thesespecial Wheatstone wires demanded a highstandard of efficiency by administrative,engineering, and operating staffs.

For instance, a certain small provincialoffice situated near a racecourse may normallynot have been an important telegraphiccentre, but during race week a transformationscene was enacted. The engineering staffhad been at work, and when the opening dayof the meeting arrived the comparatively

189

The superintending officer at a race -meeting where part of the work was done atthe town post -office and part at the grand-stand had to arrange for change over from oneto the other. In the morning the post officedid most of the work, but as the publicgathered at the course it gradually shiftedto the grandstand. The clerks moved off inlittle batches and proceeded to the grand-stand, until, by the time the racing had begun,if conditions were normal, the town .officetelegraph would be very quiet. But at thegrandstand work was maintained at full

pressure, with allcircuits going full blast.In the evenings thetown office. again gotbusy, and from theremost of the pressmessages were sent.

On " classic" eventdays, such as theDerby, or Newmarketor Ascot, the specialstaff sometimes handledfrom 11,000 to 12,000private telegrams, plus8o,000 words of" news " in a day.

By courtesy of the Pwento,,,,

A Wheatstone transmitter of 1867.

simple instruments on the regular circuits,except the purely local ones, were displacedby Wheatstone automatic apparatus. Addi-tional wires were brought in similarly fitted,and extended to the grandstand office.Perhaps this office would be equipped withsix Wheatstone and four quadruplex keyworked circuits, and an imposing array ofperforators to complete the plant.

Circuits proved and handed over, the workbegan. During the day the special staff wouldprobably reach a total of 90 men. Someworked at the counter receiving the messagesfrom the public or the press representatives,timing the forms, and taking payment. Themajority operated in the instrument rooms.Clatter of perforators appeared to pervadethe place to the exclusion of every other sound,but a telegraphist could detect the purringof Wheatstone transmitters, each reeling offslip at the rate of perhaps 300 words aminute to London, Liverpool, Birminghamand other centres.

Creed ReperforatorAt the receiving end

of the press lines, theCreed reperforator andprinter-in which anexact replica of Wheat-stone perforated slip

took the place of morse slip-eventuallyappeared.

Instead of pieces of slip being handed tovarious operators the received perforated slipwas put through another machine and theperforations automatically transformed intoprinted characters. This system is still usedby newspapers on their private wires, for thetelegraph system of Fleet Street is, collectively,a fairly huge institution. A newspapertelegraphist has not only to be qualified inmorse key and sounder, Wheatstone, andteleprinter work, but is in some cases alsorequired to manipulate the picture telegraphapparatus, at least, in normal times.

So far as the Inland Telegraphs are con-cerned, though, I am afraid that Wheatstonetelegraphy is a thing of the past.

The Central Radio office, however, stilluse the system for transmitting news to shipsand countries overseas. But the receiver iscalled an Undulator, in which morse charactersare represented by undulations.

Di coectooy of flee PostncEe,-GeneratThe Central Telegraph Office about 1920. Messages in Morse were transmitted from

here to the South Coast.


190 NEWNES PRACTICAL MECHANICS Mardi, 1943

IT is a generally accepted theory that if youwant to excel in anything, whether aprofession, trade, or even a hobby, it is

essential to specialise both in the training andthe practice of the particular branch for whichyou have a liking or, as it is sometimes termed,a " flare " ; but before taking up a course oftraining the individual is helped in hisselection by some 'sort of mental guidance.In . many people this is accomplished quiteunconsciously and extends over quite a longperiod of boyhood or youth.

An artist may have shown ability in drawingand painting in his early childhood;; somearchitects have reached the top of their schoolforms simply because of their painstaking torecord that extra fine detail in their work,and later on in life they have found themselveskeenly interested in buildings or heavyconstructional work. Most boys, -at -sometime in their teens, take up the hobby ofstamp collecting, but it is only those whoseminds find real recreation or instruction inthe pursuit of it who keeptheir collections growing andmaintained into their later years.

In like manner we camerausers are controlled ; we haveour first camera as a present,and we -expose a few spools offilm. Perhaps at first thosespools are developed andprinted for us ; this is unfortu-nate because it just takes awayfrom us all that goes to makethe enthusiastic and real ama-teur, with the result that thecamera is used only on rareoccasions. But those of uswho have taken to the hobbyseriously, and have dived intothe fascinating mysteries ofmaking negatives and prints,have been mentally urged tosee what photography offeredin the way of recreation andinterest.

Haphazard SnappingThere are thousands of very

keen amateurs, however, whoare still doing " unspecialised "work; they seem to revel intaking all sorts of subjects orobjects, and while they findlots of real enjoyment in so doing, they neverseem to come out on top with any of theirresults.

I am inclined to think that the answer is tobe found in the fact that you are " general "rather than " specialist," and so let us befrank with ourselves, for by so doing we maysoon find our results are posted on " the lineat one of the London or local exhibitions.

It is just possible that so far you have nottroubled to find out, or even to notice, thatany special subject gives you more pleasurethan others; you have quite a nice collectionof good negatives. I wonder whether youhave ever made an enlargement from aparticularly good film, mounted and framedit and then hung the finished picture in aprominent place on the wall of your diningroom. Well, if you have done this and havebeen able to live with it and not be tired ofseeing it, then there is something in it, and Ishould advise you to send it to the nextexhibition to see if it will get hung.

.PhotoAraphinA Street ScenesHints on Specialising in Group Subjects

By JOHN J. CURTIS, A R.P.S.

SpecialisingBut what about this idea of specialising ?

Do you really want to know what subjectappeals to you most ? Then go to the nearestpicture gallery -as soon as you can and spendsome time there ; do not rush around, takethings quietly, and make a few notes of theparticular pictures which caused you to stop,examine and criticise. When you havefinished the tour refer to your notes and go andlook at those pictures again, and if you findthat most of them are of a similar type, forinstance landscapes, then you have a likingfor landscape work; if they are of interiors andarchitectural subjects then that class of workis your " flare " ; if you have noted figurestudies or street scenes then you will findthat itis in the direction of these that yourmind is anxious to lead you.

You must be careful when criticising thework of masters ; I do not mean condemninga -print just because it does not appeal to you,but rather to find out for yourself what detail

The old curio shop.

or feature it is that seems to be wrong, andthen ask yourself how you would have doneit. If you do this examination carefully thenyou will leave that show with more knowledgethan you had when you entered it.

I have in the course of several years judgedand examined many thousands of photographsof various subjects, and it has always been asurprise that many more prints are not sent infor competition. There is usually a numberfrom individuals who regularly send toexhibitions and competitions, and one cannothelp noticing their work, which is usually sooutstanding. I believe that they are keen onmaking high-class pictures, and are only ableto attain a high standard by making regularcontributions to the shows ; in fact, theyrecognise that every time they make anexhibition picture they have put their verybest into it, and have learned somethingmore ; further, these picture makers arespecialists, and usually stick to one class orgroup of subject.

Group Subjects- I want to give a few useful hints on certaingroups, and will start with Street Scenes,because they offer opportunities all the yearround, and especially at this time when othermore open spots are barred through badweather. Most towns have some outstandingbuildings, and these might be modern or veryancient ; they are features of special im-portance to the town and, as such, they canbe used as backgrounds to some of our shots.That old Lych Gate makes a splendid settingfor two or three old folks standing andgossiping near it; the Entrance to thePublic Library fits in very well with thatgroup of youngsters just coming out andlooking at the books of their choice. Lookat that queue of women outside the fish-mongers ; you can tell by their faces thatthey have been there a very long time, not asmile to be seen, and what a war -time storyit makes ! Do not let them see you taking theshot ; they might be very troublesome,so

wait your opportunity. Turnaway from them after measuringthe distance by your eye andget the shutter set ready ; youmight try holding it under thearm with thumb on the trigger,and be sure to get the shopin as background. Just whenyou are going to touch thetrigger, look away from thepeople at something down theroad, so as to divert theirattention from you.

School children leaving theschool premises will give youmany good chances, but be sureto get action into the picture.Boys are particularly gcoimodels for this type of work,but avoid any posing ; watchout for a spot of fighting orheated argument, but rememberthe camera must always beready for any chance shot, asthere is never any time forpreparation. The shop whereold curios are sold is apicture in itself, but if youwait long enough you willbe sure to get an old personor couple who will stop andexamine something in the

window. If you have a friend who hasa room on the first floor of any of theshops in the main busy street, you mightbe allowed to go to the window of this andtry your hand at some high angle photography.A little group of talkers on the curb opposite.Wait for a suitable time and maybe one ofthem will say something funny and set theothers roaring with laughter ; then is thetime for shooting. Some of these " over-head " exposures are very good, but youmust as a rule be patient and, wait for asuitable subject. It is good to think thatthere are still a few horses on the road, and Ihave often noticed what fine studies somemake when standing waiting for their masterto come out of a shop.

Be careful to avoid ugly backgrounds, andif the horse is opposite a blank space, or ifyou can take the shot with the camera veryslightly tilted so as to get the sky as back-ground, you will possibly get a good headstudy ; you can perhaps chance a low angle


March, 1943

study by stooping down. In many smalltowns one can often find certain individualswho are local characters, such as you see atWhitby at the Fish Market ; three or fourrather picturesque women preparing crabs.At another place I well remember a man,quite a character, who used to sell shrimpsfrom a barrow ; he was snapped many times.Flower sellers are always to be found, andsome are good models, especially if you askthem to allow you to take their photograph.

The old-time villages around the countrylend themselves to this type of work muchmore than the average suburban streets, buteven these can be put to good account if youfind the right spot, and by this I mean thebackground, for this very often links up orgives purpose to the picture.

Exposure TimesI have found that it is necessary to give

.fast exposures, and for this reason to use thelargest stop, F6.8 or F4.5, if you have themon your camera. A fast film will then permitan exposure of something like '25oth orijksoth, according to the time of day, andthe power of the light. I try to make use of inclined to be drab, and this tends to flatnesssunlight wherever I can, for it does make a in the negatives.big difference in the work, as without a Generally, when enlarging these negativessuggestion of sun the best of our streets arc it is necessary to cut out quite a lot of the


The crab stall in front of a seaside cottage.

191

CR1104 OSTEP

CRABS DRESSED

FRESH .5DMIE

Matter which got into the exposure ; you mustuse only that part which is subject matter, asif anything else is allowed it will certainlydetract the eye and spoil the whole theme.

Azrcraft of To-MorrowDetails of Construction 'and Operation, and Possible Future Development

THE future trend of aircraft design willundoubtedly be the use of far largertypes than are in service at the present

time. As engines are developed and new

Air -liner

0 0 0 0

By T. E. G. BOWDEN

by a machine loaded to 6o1b. per sq. ft. Thesedisadvantages are being overcome by extensiveresearch, and the following notes describesome of the methods likely to be adopted.

Tanket

Pipe LineFig. I. Method of refuelling an air -liner in flight.

materials brought into use, aeroplanes weigh-ing 15o or even zoo.tons are feasible, althoughtheir shape will vary immensely from thealmost universal standard of to -day.

Wing LoadingsWing loadings of over 351b. per sq. ft. are

rare at present, blit figures of up to So or9olb. per sq. ft. will be common in the future.The reasons for this likely in -crease are asfollows. By increasing the wing loading, thewing area is decreased, e.g., if the figure risesfrom 4o to Solb. per sq. ft. the wing area ishalved, thus decreasing the weight and thedrag. The speed will consequently be in-creased without using engines of a higherpower output- Owing to the reduction inwing size the amount of material and labourrequired is also made proportionally smaller,reducing the cost of production. More air-craft may be stored in the same space whenwing loadings are made greater. The mainfactor is the increase in speed with equal loads.

The disadvantage which high wing loadingsincur are not insoluble. The chief difficultyis the increased stalling and take -off speedswhich call for large aerodromes. Climbingspeeds are reduced, control difficulties ex-'perienced and manoeuvrability affected. Afighter aircraft with a wing loading of 3olb.per sq. ft. can turn in half the radius required

Rocket ProphlsionAssisted take -off to overcome

the long run required by heavily -laden aircraft is practicable,and is being carried out at thepresent time. Rocket propulsionwill be more commonly used asmore information is gatheredabout the various types of fuels.By fitting rockets to aircraft the

take -off speed required is gained veryquickly and thus smaller airfields are madepossible. An aircraft requiring a normaltake -off run of one mile could becomeairborne after only half a mile by the use ofrocket propulsion. Germany has alreadyfitted rockets to tfie Junkers Ju. 88, and ap-parently has had some success. Rocketpropulsion is least efficient where the airdensity is high, and is most efficient in regions

WID a. mama a

Fig.z.-All-wing types of aircraft. '

Engine in Wing Engines in Fusela

Spars Shafts

Fig. 3.-Diagrams showing positions of " buried" engines.

of low density. This points to the fact thatfuture stratosphere aircraft will be propelledby means of rockets. Before rocket propulsionalone is utilised, it will probably be used as anadditional source of power to the normal aero-engine and airscrew method.

Catapults such as utilised by naval aircraftare hardly practicable for large passenger -carrying machines, and it is doubtful whetherthey will be used in the future for civil pur-poses. This method has been utilised toshorten the time required for mails to bedelivered across the Atlantic. French andGerms ). liners have been fitted with catapults,and by flying an aircraft from the ships whenseveral hundred miles from their destinations,an appreciable_ amount of time may be saved.

A modified form of catapulting, i.e., groundacceleration in which the aircraft is mountedon a carriage and drawn across the airfield ispracticable, but probably will be limited tothe smaller size of aircraft. By using thismethod the take -off run may be reduced byhalf and none of the discomfort and dangerexperienced in the catapult method incurred.

The aircraft need not bestressed for as high loadfactors as is necessarywhen designing forcatapulting, consequentlyreducing the structuralweight.

Flight RefuellingRefuelling in flight,

which has already beenproved* a practicableproposition, will no doubtbe developed for long-distance freighters flyingnon-stop from Englandto Australia or China.This' method allows air-craft to take -off with asmall petrol load and thusa reasonable wing loading,



and to he filled up when safely airborne,increasing the wing loading to what would bea dangerous figure for take -off.

The advantages of flight refuelling are asfollows. First, very few structural alterationsare required in the air -liner, certainly not somany as required when fitting rockets.Secondly, no elaborate ground mechanismsare required as only a tanker aircraft is neededand this is fully mobile. Thirdly, the take -offof the air -liner is perfectly normal and it doesnot have to stagger off the ground withabnormal loads. The wing loading is increasedonly when plenty of height is available formanoeuvring. The disadvantages of thissystem are the facts that low visibility mayprevent refuelling and that, at the very mini-mum, one aircraft is required at each base fortankage purposes.

The actual method which will be used forflight refuelling will probably be similar tothe present-day system, which has beendeveloped by Sir Alan Cobham. A briefdescription of the manner in which fuel ispassed from the tanker to the air -liner (orbomber) is as follows. The tanker flies aboveand slightly behind the air -liner, which trailsa line as shown in Fig. r. A line is thrownfrom the tanker and engages with the trailingline by means of a grapnel. The line is thushauled up into the tanker and a petrol pipeattached, following which the line and pipeare drawn back to the air -liner and connectedto the petrol system. Before petrol is passedthrough the pipe, it is flushed with nitrogento reduce the danger of fire. After the re-fuelling has taken place the line is flushedwith nitrogen again and the delivery pipehauled back to the tanker. Although themethod may seem rather complicated, it iscertainly a solution to high wing loadingtroubles and will almost certainly be used inthe future.

A typical aircraft designed for flightrefuelling could take off at 351b. per sq. ft.

' and be refuelled up to 6olb. per sq. ft.,giving a range of 4,000 miles with a payloadof ro,000lb. and an all -up weight of 6o,000lb.

Mails and other priority freight may also betransferred from the tanker so that as littledelay as possible is incurred.

All -wing AircraftThe idea of an all -wing aircraft has had

many advocates in the past and no doubt adevelopment of this type will be flying in afew years. The larger the aircraft" is, themore space is available for payload owing tothe great depth of wing required to lift theheavy load. The Junkers G. 38 was the firststep in this direction, with a span of 146ft.and a weight of 53,000lb. Thirty-fourpassengers with a crew of seven were accom-modated in the fuselage and wing. Owing tothe thickness of the wing, the engines couldbe maintained in flight. Possible shapes for afuture all -wing air -liner are illustrated inFig. 2, one provided with swept -back wingsto give longitudinal stability and the otherwith tail booms to support the elevatorsand rudders. These booms could be utilisedto house the fuel tanks or compact payload.

Flying -boatsThe question as to whether the aircraft

of the future will be flying -boats or land'planes requires careful consideration. Bothhave their advantages and disadvantages.Flying -boats do not require large, carefullyconstructed airfields, which are very expen-sive. On the other hand they are liable todamage by any flotsam that may be floatingon the take -off line. A very small piece ofwood can easily tear the bottom out of aflying -boat travelling at too knots. Land'planes possess the advantage that they canbe designed with a very much moreefficient aerodynamic shape, and in largeaircraft the consequent saving of drag is

considerable. A flying boat must possess aplaning bottom, and a step which in thefuture may be made retractable. The weightof the landing wheels, supporting structureand retracting jacks are a very heavy item inthe case of land 'planes and they also sufferfrom the disadvantage that should one beforced down on the sea, little chance ofsurvival may be expected. A large flying -boat, if forced down, could taxi along on thesurface to its destination, and no doubtwater propellers will be fitted for thiscontingency.

The surface finish in future aircraft will beabsolutely smooth to reduce the drag to aslow a figure as possible. All the points mustbe flush and no external projections allowed,except observation hatches, which may beretracted into the fuselage when not required.It has been found by experiment that ex-tremely small excrescences can cause anincrease of 3o to 4o per cent. in the drag.Moulded plastic fuselages and wings producean extremely smooth surface, and this typeof construction will undoubtedly be utilised.An interesting note on the effect of surface

Engine

ShaftFig. 4.-Aeroplane with pusher airscrew.

roughness which is apparent on present-dayaircraft is the fact that military aircraft,when camouflaged, suffer a loss in speed ofseveral miles per hour. This is entirely dueto the rough surface finish of the paintedsurfaces. Another important fact connectedwith surface finish is the question of gapsand leaks. No holes connecting the upper andlower surfaces of the wing or the inside ofthe fuselage to the outer air flow will bepermitted, as loss in lift and increase in dragoccurs if this is allowed.

Pressure CabinsPressure cabins in which the air density is

maintained at a reasonable figure to preventdiscomfort have already been developed andwill become commonplace in the near future.The main difficulty is the manufacture of aleak -proof cabin which is not too complicated.

Inlet

CompressorFig. 5.-Diagram of a jet-propelled

Land 'planes are more suitable for the in-stallation of pressure cabins than flying -boats,due to the fuselage profile. Circular sectioncabins are the most efficient for pressurepurposes, being easily incorporated in land'planes, but they would cause excessiveweight -in the case of flying -boats.

The power units on all future aircraft willdefinitely be housed either inside the wingsor fuselage and will not protrude as on present-day aircraft. As the size of aircraft increases,the design of buried engines will be facilitated,and layouts as shown in Fig. 3 are probable.Pusher airscrews will supersede the tractortype for the following reason. The airflowin the case of the tractor type, i.e., an airscrewpositioned forward of the wing leading edge,causes turbulation and disturbs the flow overthe wing. This turbulence increases the drag,whilst a pusher airscrew, shaft driven, allows agood aerodynamic shape to be obtainedresulting in maintenance of laminar flow overthe wings. An alternative position for the

airscrew in the case of the smaller type ofaircraft is illustrated in Fig. 4, i.e., protrudingfrom the tail. A long shaft is the main dis-advantage, but in combination with a reversiblepitch airscrew which may be used as an airbrake, a very efficient and controllable aircraftmay be obtained.

Control SystemsPresent-day control systems are not very

efficient when flying at high velocities as theytend to " freeze " solid, and in the futurenew types of controls must be developed.The force required to operate the normalailerons, elevators, and rudders, when travel-ling at over 400 m.p.h., is very high and theytend to become immovable. Boundary layersuction is one answer to the control problem,and experiments have already been carriedout to test the results when the wing boundarylayer is disturbed. Manoeuvring by varyingthe pitch of the airscrews is also a probability.

Aero-engines fitted to aircraft designed tofly in the stratosphere will be fitted withsome form of exhaust turbo -compressor.By this method the exhaust gases are utilisedto drive the compressor, and thus avoidtaking power away from the normal output.The reason why a supercharger is required isthe fact that as the air grows less dense,the weight of the combustible mixture issmaller, resulting in a loss of power. Byfitting an impellor the air is forced into thecylinders, thus increasing the power output.The exhaust driven type of supercharger ismore efficient at great heights than at lowerlevels owing to the varying pressures of theexhaust gases and the atmosphere. Thehigher the altitude the greater the pressuredifferences and therefore the greater thespeed of the impellor. The disadvantage ofthis system is the fact that a back pressurein the exhaust system is caused, and thisnecessitates the fitting of a special valve toprevent damage due to backfires.

air -liner.occurring at the entry.

It is interesting to note that using a normalpetrol -driven air compressor the jet propulsionsystem appears to be more efficient at loweraltitudes than at higher altitudes. The maindifficulty is the space taken up by the tube andthe difficulty of arranging passenger accom-modation. An alternative layout would be tohave two jet propulsion tubes, one in eachwing, thus leaving the fuselage for payload.

AutogirosAutogiros and helicopters are bound to be

developed for taking off and landing in smallspaces, although their use is unlikely for thelarger types of aircraft. For inter -townservices and mail delivery they would beideal, e.g., landing on flat roofs in the heartof great cities.

From the above description of the possibledevelopments in aircraft design, it will beseen that the scope for new ideas is unlimited,and that very remarkable steps forwaid willtake place in the near future.

Jet PropulsionJet propulsion has great possibilities, and

it is quite likely that aircraft using this methodwill be common in the future. A layout of alarge air -liner propelled by jet propulsion isillustrated in Fig. 5. The principle of thesystem, explained very briefly, is as follows.Air is allowed to enter at the nose and flowsinto a chamber which owing, to its shapereduces the velocity and increases the pres-

sure. It then passesthrough a compressorwhich increases thevelocity and also thetemperature. Finally,the air is ejectedvia the tail at agreater velocity andtemperature than that



THE armature ran between the fixedelectro-magnet field coils which werearranged round each side of the circum-

ference of the wheel and projected horizontallyinwards, adjacent poles being alternately Nand S, and the poles immediately facing eachother also of opposite sign. As the armaturediscs or coils moved from one pole position toanother, and so cut across opposite magneticfields, the induced electromotive force gener-ated changed direction simultaneously in eachcoil. The voltage measured at the terminalsof the machine would be found to vary in thesame manner at would that of a single coilrotating uniformly between the magnets of atwo -pole machine. Fig. 3 illustrates a Coppertype alternator built by Crompton & Co.,Ltd.

All of the machines mentioned so farproduced currents of the so-called,

single-phase " nature. There wereno difficulties about using this sort ofcurrent for -lighting or heating, but itcould not be utilised satisfactorily foroperating motors. In 1891, however,the problem of using alternatingcurrents for power purposes was solvedat the Frankfurt Exhibition by the useof currents differing somewhat incharacter from the ordinary, or single-phase, current.

Two-phase AlternatorConsider the simple Gramme ring,

withits continuously -wound conductorand arranged to revolve between thetwo poles of a magnet. If, for example,two tappings be taken off the contin-uously -wound conductor at the oppositeends of a diameter a . single-phasealternating ,current will be obtained.Now suppose that two more tappingsare made at the opposite ends of asecond diameter at right angles to thefirst,' then another single-phase currentwill be obtained. One of these twocurrents, however, will reach its maxi-mum value after the other at an interval oftime represented by a quarter of a revolutionof the armature. The machine would there-fore be generating two currents differing inphase by 90 deg. ; in other words, a two-phase alternator.

Consider now an identical Gramme ring,revolving between two poles as before. Ifthree tappings only .be made, each spaced12o deg. apart, between any two of thetappings a single-phase supply could be taken.The three currents, however, would eachreach their maximum values one-third of arevolution apart. The machine would begenerating three currents differing in phaseby 120 deg. This is called a three-phasealternator with a mesh -connected armature.

If now the armature coil be cut into threeequal portions, and the corresponding endof each of the three coils so produced bejoined together at a common junction and theother free ends taken to separate collectingrings on the spindle, the armature is said tobe star connected.

The modern alternator, though modifiedvery much in details of construction, workson these principles, and although single-phase, two-phase and three-phase machineshave been built, the majority of present-dayalternators are built for three-phase working.

The very early small machines for laboratory

The Distribution of Electricity.Cantor Lecture Given Before the Royal Society of Arts

By E. AMBROSE, M.I.E.E.

(Continued from page 162, February issue)

purposes were hand -driven, but as machinesbecame larger mechanical motive power wasnecessary. For this purpose gas, oil or steamengines, and where it is available, waterturbines, are used.

The TransformerThe transformer is a piece of apparatus

capable of changing an alternating current atone voltage into an alternating current atanother voltage. The principle of the trans-former was established by Faraday in 1831,when he made his famous experiment withan iron ring on which he had wound two coilsof wire.

In his original transformer, Faraday useda welded ring of soft, round bar iron, ;in.

01104.111'.111

Fig. 3.-An early alternator with armatureconsisting of bent flat strips of copper.

thick, the diameter of the ring being 6in.Round one part of this ring he wound about72ft. of copper wire, i/.2ain. in diameter, inthree layers, about one-half of the ring beingcovered in this way. On the other half of thering a length of 6oft. of copper wire waswound in two layers. The three -layer, orprimary coil, was connected to a battery, andthe .other coil, the secondary, was connectedto a simple galvanometer. Mention hasalready been made of the way in whichFaraday conducted his experiment. Had hesupplied the primary circuit with a rapidlyalternating current, he might have obtainedan alternating current in the secondarycircuit ; but his galvanometer would nothave indicated the presence of this currentif the reversals were too rapid to give theneedle time enough to move with each pulsa-tion. Furthermore, there might have beenconsiderable heating of the iron ring, due tothe eddy currents set up by the rapid changesin magnetisation. The circulation of eddycurrents in the iron represents a loss, andthis can be reduced by building up the corewith small diameter iron wire or thin sheetsof iron. Early illustrations of these methodsare recorded in the transformers of Varleyand Ferranti.

About 1852, Varley constructed a trans-former with iron wires forming the core.

He took a bundle of wire of approximatelyequal lengths, and over this bundle woundthe primary and secondary coils. These coilswere placed in the middle of the bundle,and extended along it for a distance of aboutone-third of its length ; the iron wires there-fore protruded from each end a distance equalto the length of the coils. The two ends ofthe iron wires were then turned over theoutside of the coils and made to overlap eachother. In this way the coils were completelyencased with iron. Space was made, however,for leading through the connecting wires.Varley was perhaps a little ahead of require-ments, because, at that time, the need foranything except small transformers did notexist, but some thirty years later transformers

were built by Ferranti which were afurther development of the type.

Ferranti took a quantity of thin stripsof iron, divided into six bundles andplaced side by side. Over the middleof this he wound a layer of thickinsulated wire or strip, to form thesecondary coil. Finer wire to form theprimary coil was wound on a convenientframe in sections, and slipped over thesecondary. The ends of the iron stripswere then turned over the coils, onehalf over the top and the remaininghalf over the bottom, their ends meetingand overlapping in a similar manner tothe iron wires in Varley's transformer.The whole arrangement of core andcoils was then placed in a cast-ironframework, made in two halves, andsecurely bolted together.

When a transformer is at work acertain amount of heating takes placeowing to the eddy current losses in theiron of the core and resistance lossesdue to the flow of current in thecopper of the primary and secondarycoils. In the comparatively small trans-formers, such as those already described,the heat generated was carried away byradiation into the atmosphere. Subse-

quently, when transformers were requiredfor considerably higher voltages, it becamenecessary to immerse the core. and coils ininsulating oil, thus diminishing the risk ofelectrical discharge between the high -voltagecoil and the frame or the low -voltage coil ;it also greatly reduced the risk of personalshock due to accidental contact with the coils.

The transformer, then, is a comparativelysimple structure. There are no rotating parts,and the chief elements of its construction area magnetic circuit comprising the core, twoelectric circuits comprising the primary andsecondary windings, and the auxiliaries com-prising tanks, oil and cooling plant.

The Electric ArcIn 1800, the year Volta announced the

construction of the voltaic pile, Sir HumphryDavy mentions experiments in which electricsparks were obtained between two carbonpoints caused by a voltaic pile, and in 1810he showed to a distinguished audience,assembled in the theatre of the RoyalInstitution in London, the brilliant lightthat was produced by passing a current ofelectricity through two pencils of charcoalabout an inch long and one -sixth of an inchin diameter, the points being placed end toend and slightly separated from each other.The only available source of electricity in


194 NEWNES PRACTICAL MECHANICS March, 1943those days was the voltaic cell, and a batteryconsisting of 2;000 of these cells was usedfor the demonstration. Foutault, in 1844,instead of using charcoal, as DaVy did,made use of carbon from the retortsof gasworks, which is' much harder anddid not burn away so quickly. Foucaultconstructed a hand -regulated arc lamp whichDelcuil is said to have made use of in showingthe first electric light in the Place de laConcorde, Paris. The next step was to devisemeans for. automatic adjustment of the -carbons, and the first apparatus of this kind.was devised by Thomas Wright, of London,in 1845. This was carried a step further byStaite in 1848, when he made use of the currentof the arc for the regulation of the carbon.

A phenomenon of the direct -current arc isthat the positive carbon burns away atapproximately twice the rate of the negativecarbon, and the end' of the positive carbonbecomes cup -shaped whereas the negativecarbon becomes pointed. This is thought tobe due to bombardment of the positive carbonby particles flying off the negative.

"Jablochkoff Candle "In 1876 Paul Jablochkoff invented the

famous " Jablochkoff Candle." This con-sisted of two parallel carbon rods separatedby a layer of plaster of paris. A thin plate ofgraphite laid across the carbon -tips and heldin position by a paper band serves to light thecandle. The arc thus formed maintaineditself between the carbon rods, volatilisingthe intervening partition. Owing to theunequal burning away of the carbons withdirect current, these lamps were found tooperate best with alternating current.

The pioneers of electricity supply started byexperimenting with arc lamps for lighthousework. Experimental installations were triedat Blackwall in 1857, then in 1858 at SouthForeland and 1862 at Dungeness. The arclamp was only suitable for the lighting oflarge areas, and one of the first installations ofthis kind was at the Gare du Nord, Paris, in1875. Within the next three years a numberof Jablochkoff candles were installed in thesame city : some at the Grands Magasinsdu Louvre, and others for street lighting inone or two of the important avenues. InDecember, 1878, Jablochkoff candles wereinstalled along the walls of the ThamcsEmbankment, London, between the Waterlooand Westminster bridges. Other installationsusing the same type of lamp were tried, butthey all failed subsequently because of thehigh cost when compared with gas lighting.

The Incandescent LampWhen a current of electricity flows through

a solid conductor, heat is developed and theamount of heat so developed is proportionalto the total energy expended in the conductor.This energy is proportional to the product oftwo factors, the strength of the current andthe difference of potential, or the voltage,between the extremities of the conductor,necessary to maintain the current. So thebest developed is proportional in amperesmultiplied by volts (t ampere multiplied by

volt equals t watt). It was not very longbefore men conceived the idea of using theheating effect of a current upon a conductorfor illuminating purposes, and patents basedupon this principle were taken out. In 1858Jubart proposed to make use of a small carbonrod in a vacuum. Moleyns, of Cheltenham,took out a patent for a lamp which had aglowing platinum spiral upon which coal -dustwas allowed to fall. In 1859 Du Moncelobtained very good results by. experimentingwith carbon filaments of cork, sheepskin, etc.Between the years 1877 and 188o the incan-descent glow lamp began to take practicalform, and Edison in America and Swan inthis country were independently working onsimilar lines. The first glow lamp constructedby Edison had platinum wire for the filament.

Edison examined the properties of manyorganic and inorganic substances, with a viewto finding the best substance for the filament.He fixed finally upon bamboo fibre.

Edison -held the view that to give the carbonthe highqt possible resistance and thesmallest tendency to disinteiration, it shouldretain its structural character. Swan, on theother hand, maintained that the structure ofthe material should be entirely destroyed, andthe carbon filament made as dense as possible.Long before Edison he tried to obtain moredurable carbon filanients.

The filament of the Swan type lamp wasmade either direct from cotton thread or from

Fig. 4.-WalterBailey'smachine.'

thread formed by squirting a solution ofcellulose through a fine nozzle at high pressure,cellulose being the chief constituent of suchvegetable substances as cotton, paper, etc.

Early in 1900 experiments were renewed toobtain a satisfactory metal -filament lamp inplace of the carbon filament. - About theyear 191 t lamps were made with filaments ofthe metal tantalum. This metal was foundunsatisfactory, mainly because it was notpossible, owing to its low specific resistance,to make a lamp satisfactory for voltages inexcess of about 125. In 1914 tantalum wassuperseded by tungsten. With this metal,lamps for voltages of 235 to 25o could be made,and as the filament could be run at .a tempera-ture some 300 deg. C. above that of thecarbon filament, there resulted a greatimprovement in the efficiency, the consump-tion of the new lamp being just under one-halfthat of the carbon lamp. Of recent' years theefficiency has been further improved byoperating the filament in an inert gas (argonor nitrogen) instead of in vacuo.The Electric Motor

As early as 1830, that is, before the resultsof the Faraday experiments on electro-magnetic induction became known, variousexperimenters constructed apparatus whichtranslated electricity from primary cells intomechanical work. In general, the apparatusconsisted of a long, straight bar of metal sup-ported rather like the beam of a pair of scales.Attached to the beam on one side of thefulcrum was a fixed piece of iron, called thearmature, which was influenced by an electro-magnet fixed immediately underneath. Atthe end of the beam, on the other side of thefulcrum, was fitted a rod which acted as apawl to a toothed wheel. The electro-magnet,on being energised from a battery, attracted thearmature which tilted the beam and so movedthe wheel to the extent of one tooth. Thismovement actuated a switch in the batterycircuit and, the current being cut off, the leverreverted to its original position. This sequencethen repeated itself, and so the axle, on whichthe toothed wheel was fixed, rotated. Othersimilar devices were constructed. In 1845Froment constructed a machine which showeda great improvement. It consisted "of twowheels mounted a short distance apart on the

same axle, and at intervals around the peri-phery,- soft iron bars were fastened, in linewith the axle, the bars rigidly connecting thetwo wheels. Mounted on a framework whichcarried the axle were four pairs of electro-magnets so arranged that they would attractthe soft iron bars on the wheel and bring abouta continuous rotation. Current for energisingthe electro-magnets was supplied from abattery and was periodically interrupted by .acommutator attached to the axle of the wheel,the whole being so arranged that the two elec.:,tro-magnets which were being approached bythe iron bars on the wheel were being ener-gised in turn.

Various motors were constructed in whichthe reciprocating motion of an iron plungerinside a solenoid was made to transmit motion,in much the same way that the motion of asteam engine piston is utilised.

Pacinotti's Ring ArmatureA great advance was made in 186o when

Pacinotti invented the ring armature which,it will be remembered, was improved and usedby Gramme in the construction of his dynamo.Notwithstanding, Pacinotti built a small modelmachine in 186o which he called an electro-magnetic machine. He failed, however, tobring it to such perfection as to justify itsadoption for practical use.

In 1867 Siemens observed the reversibilityof the dynamo. If the armature of a dynamoelectric machine be made to rotate, as does thering of a Gramme machine, currents are pro-duced in the coils of the ring which may beutilised for the excitation of the electro-magnets, and for giving a supply to the externalcircuit. If the process be reversed', i.e., if theterminals of the machine are connected to asource of electricity supply, the electro-magnets will be excited and current will alsoflow in the armature. The magnetism pro-duced by the armature coils will be affected bythe fixed electro-magnets, the armature willrevolve and continue to do so as long as the

` current flows through the coils of the machine.A public experiment in the transmission of

power by electricity and _its conversion intomechanical power was made during theexhibition at Vienna in 1873. A Gramme, withpermanent horseshoe magnets, driven by asteam engine, was used as a generator, andcurrent was conveyed to a similar machineabout 500 yards distant.

When considering the alternating currentmotor the solution is not quite so simple,particularly with regard to single-phasecurrents, because with the rapid reversals ofthe current, the armature conductors would bepulled alternately in one direction and thenin the other, with the result that no movementwould take place.

As early as 1824 'Arago observed that whena copper disc is made to rotate in its ownplane, and a magnetic needle is placed over it,the needle turns round in the same direction

- as the disc. A part of the field from the mag-netic needle passed through the copper disc,which, on being rotated, cut the magnetic linesand thereby induced currents in the copper.

In 1879 Walter Bailey showed how Arago'srotation could be produced by a number ofelectro-magnets acting on a copper disc.Below a pivoted disc he arranged four electro-magnets with their vertical axes equidistantfrom the centre. The magnets were excitedby currents from a battery, and a commutatorwas used for alternately reversing the polarity.By causing the current to be reversed rapidly,the effect of a rotating field was produced.(Fig. 4.)

On this principle the modern alternatingcurrent induction motor is constructed. Arotating field is produced by winding on thefixed part of the machine coils displaced at96 deg. or 120 deg. apart, to which either atwo-phase or three-phase supply is connected.

(To be continued)


THE main principles and objects ofanything new must be planned andconsidered in a broad way before much

detailing is attempted ; detail work, inconnection with engineering particularly,follows with comparative ease once it is knownthat the principles and requirements arepractical and economical. Houses which arepractical and economical provide a greatfoundation for engineering enterprise, andabove that foundation must rise something

Fig. 6.-Consider the effectsof these houses with well -set -outgardens, loggias, and roofgardens, trees, general sur-roundings, scenery, sunlight and

good distant views.

else than the practi-al and financial aspecti,and that is, good design which will nevercause the artist -mind to be shocked. I amnot an artist ; nor by law an architect ; buta structural engineer and building technician ;and I know that architects will be called onto assist the engineers in many mattersconnected with the proper designing andproportioning of the units of the pre -builthouses of the post-war period. I.,also knowthat women will exercise their minds (andtongues) in the great subjecpt of house design,equipment and decoration. In the firstarticle of this series enough general evidencewas given to engender a keen interest in asubject which many millions of people musthave in mind. Now further advances will hemade to literally force this keen interest intopractiCal action.

The illustration, Fig. 6, is a simple isometricbird's-eye view of a row of engineer -designedand built houses, some of which are completedand others semi -finished or in course oferection. Note the entire absence of scaffold-ing, ladders, mortar bins, bricks, stacks oftimber, joinery and other materials, and theusual array of things which littered a housingsite in pre-war days for weeks, if not months.Next, study the manner by which in main


EnAineer-built Houses ofthe Future -2

New Principles, Speedy Construction, and Comparative CostsBy R. V. BOUGHTON, A.I.Struct.E.

principle (of course bettered as knowledgeincreases) the pre -built structural units offloors, walls and roofs would be transportedto site and erected by a mobile crane, themain parts of which would be lowered on tothe chassis when work is completed. Theview, with its comprehensive annotations,should make it manifest that the houses mayvary very considerably in the design of thegeneral outline, disposition on site, types andshapes of roofs, location and proportion ofbays, design of windows and doors, theprovision or otherwise of roof gardens withloggias if desired, and even a shallow bathingpool could be constructed in the flat roof.

made to one pattern so as to ensure accurateand speedy application of the finishing partto the structural part. When setting out, andground and base work has been completed,the erection would commence, and continueuntil completion is effected to each house, ofall structural units in : ground story, in-cluding ground floor, walls and partitions,fireplace and flue units, window and doorframes combined in the units, the first floor,the structural parts of the combined pre -builtfittings and equipment, the stairs and otherparts. This -procedure would cause thebuilding to be structurally complete up toand including first floor, or to a stage which,

A-Loaded lorry with units ; B-An impression of a mobilecrane ; C-The land of the housing estate ; D-Pavement ;E-The road ; F-The structural units of ground storyin position ; G-One of the pre -built units being loweredinto position ; H-Roof structurally complete and readyfor finishings ; J --Flat roof with stairwell and cisternenclosure, small fire stack, guard walls, railings and roofgarden ; K-similar to j, but with variation in positionand structure of stairwell ; L-the combined pitched andflat roof with stairwell enclosure, guard walls, railings and

roof garden. M-Front gardens ; N-Garage ; 0-Rear fences.

The design,with variousunit al varia-tions, may beadopted fordozens of different types ofplans, a few of which will begiven in the next article. Thealternation of blocks of houseswith ail -flat and combined pitched andflat roofs will not only help to break anymonotony caused by an unbroken roof line,but the limited depth of pitched roof wouldassist in maintaining the old traditions of thesteeply sloping roof. The method of pre-senting the bird's-eye view by isometric pro-jection is to allow elevations and roofs to beshown clearly ; the reader lc ill understandthat a different view would be obtained fromground level-the elevations would be muchmore in evidence than the roofs.

Order of Erection, Finishings andEquipmentIn compliance with a general principle of

pre -building which I advocate, the variousunits would be composed, where it applies,of separate structural and finishing parts,each part, although being separate, would be

"0 -

in timber construc-tion, is known mAmerica as the firststage of the platformframe system. This

good system provides a platform foroperatives to work upon to assist in theerection of the first story units. After theground story is erected, the units, similar tothose specified for the ground story, areplaced in position up to and including theroof units, although the pitched roof membersmay be fixed a little later if practical con-ditions make this course advisable. Water-proofing and sealing the joints of units exposedto the weather would proceed during erection.The finishings to floors, walls, partitions,ceilings, roofs and all other members andparts exposed to view and as required canthen he applied. The majority of thiswork would be of panel formation, shapedto and being part of the structural members



to which they are to be fixed. Next will bethe fixing of sashes to windows, deliveredglazed and complete with all fittings, doorssimilarly complete, stair finishings, equip-ment and built-in furniture items, sanitaryfittings, boilers, hot and cold water units,fires and various other assembled units. Thelimited amount of plumbers' work wouldproceed in conjunction with the work. Theinstallation of electrical work will cause notrouble and proceed with the general finishings.

External ServicesThe external services include important

sections of work as water, gas and electricityservices, drains, piths and fences. Notmany of the old principles and details will befollowed by the designers and builders ofthe engineer -houses. The running of theservices can conform to much better codesof practice than have hitherto been practised ;drainage inspection chambers may be ofstandard and complete units ready for placinginto position and connecting to the pipes ;paths may follow old principles ; fences willcertainly not be constructed with short -lifetimber buried in the ground.Speedy Construction

Speeds in erection and habitation of dryhouses are two of the many advantages of pre -building which does not call for the building,assembly and application of anything like thegreat quantities of materials specified in thefirst article of this series-over 50,000 bitsand pieces in each house as well as several tonsof cement, many cubic yards of ballast andsand, and hundreds of gallons of water, etc.The pre -built units to form the floor, walls,roof and other parts of each house will num-ber a few hundreds only in structural andfinishing units, the majority of the smallitems in the units being mostly machine -madeand assembled ready for speedy and accuratefixing on site ; and each unit would be com-paratively light in weight to give sufficientstructural strength and ease of manipulation.Further study of Fig. 6 will give an indicationthat there is every opportunity, with quite alimited number of skilled, semi -skilled andunskilled operatives, of erecting the structuralunits of one house in two or three days, and

under certain conditions of organisation thistime may be shortened. The finishings shouldbe done under the same time limits. In myconsidered opinion, a house should be readyfor habitation in about a week from the dayit is set out.Catalogued Units

We already have catalogues of manystandardised building units, such as metal andwood windows and doors of various types andsizes, all machine -made ; we have many itemsused in building which conform with BritishStandards specifications which are machine -made; we have machine -made bricks, tiles,floorings, fittings and hundreds of othermaterials and goods-all made with thescientific, technical, and commercial know-ledge of engineers.

It should be manifest that a sane collectionof all these advantages hitherto provided bythe combined brains of engineers and builderscan and will produce comprehensive standardschedules in catalogue form, which willprovide architects and builders with hundredsof standardised pre -built units suitable forevery practical want in the planning, includingsize of various rooms, etc., for the elevationaland sectional needs including heights ofstories, and to conform not with the archi-tectural genius of such old masters as Wren orBarry, or the atrocities of the jerry builder,but something at least equal to, and probablybetter than, the efforts of the box designers ofthe decades between this and the last war ;and, what is of extreme importance, thegeneral planning and equipment of theengineer -designed, built and catalogued housewill have those arrangements and equipmentwhich suit the housewife.Cost of the Houses

It is, of course, prudent to discuss costsonly in proportional sense. It would beunwise to prophesy the costs of materials andlabour after cessation of hostilities, but it issafe to state that a pre -built engineer -designedhouse, exclusive of land, will cost abouttwo-thirds of the post-war cost of the ordinarypre-war type of house of equal accommodation.This statement alone is insufficient, as thereare several other factors to consider with the

utmost care. Land and road charges will besimilar for all types of houses of equal landfrontage. The cost of new houses after thewar will, in all probability, be much higherfor a number of years than the cost of housesbuilt in the last decade of the pre-war period.These two factors may have a balancing effecton the values of pre-war houses and engineer -built houses, and, of course, show a con-siderable direct advantage of a new engineer -built house over a new brick -built, Weil, roofhouse. This practical financial subject maynow be extended into the field of many otherdirect and indirect financial advantages andthey are : Pre -built machine -made units com-plying with a good specification assure pre-cision and almost entirely eliminate the useof bad materials and workmanship, andcertainly avoid the curses of jerry building;and they do not require the jobbing -builder -surgeon to use his sundry impedimenta,ranging from transport of much plant, throughthe various processes of hacking, sawing anddirt making to making good, and dabs of paint.Instead, it will mean referring to the Book ofInstructions and Schedule of Units and order-ing what is required, which will be eitherfixed by the local builder or by the house -owner. Financing by building societies, orlocal authorities should be simplified con-siderably (as will be explained in a futurearticle of this series) as all parties will knowexactly the position as to the quality of thehouses. The duties of building inspectors oflocal authorities will be lessened as their mainconcern will be connected with foundations,bases and drains as to other parts of thestructure, they will know that the best brainsof the engineering professions have designedall structural and finishing works to guaranteetheir compliance with the best principles anddetails. House owners will not be burdenedwith heavy expenditures on repairs anddecorations, for the simple reason that therewill be no cracked and defective plasteredceilings ; no slipped and broken roof tiles orslates; no settlements in walls, no jammingwindows and doors, no defective hot-watersystems, no freezing -up in winter, and notvery extensive essential protective decorations.

(To be continued.)

Minesweeping by Air

After many experiments during the early part of 1940, the idea of exploding magnetic mines from the air was determined, and a number of air-craft were fitted with degaussing gear. The illustration shows a Wellington aircraft at work, fitted with the speeial mine detonating device.



BEFORE laying lino over ordinary floor-boards care should be taken to see thatall tacks or nail heads are removed or

1:-..anmered flush, otherwise the lino will wearthrough quickly. If the floor is an old oneknots may stand proud of the surface, andmust be levelled with' a chisel or plane.Another trouble is uneven boards, and, inthis case, it will be necessary to trim off theupstanding edges with a plane.

In order to make a good join when layinglino a proper knife and a " straight -edge "should be used. The best kind of knife is onewith a hooked point, as shown at A, Fig. t,but a shoemaker's knife (B) makes a goodsubstitute. For a " straight -edge " a pieceof wood 3ft. to 4ft. long and about 4in. wide,with a planed edge, can be used.

After marking the piece of linoleum whereit is to be cut, hold the piece of wood down

Fig. 2.-Using 'a " straight -edge' when

firmly, and use the planed edge as a guidefor the knife, as shown in Fig. 2. To keep theknife sharp, rub it on a water -stone or on apiece of fine emery sloth wrapped round aflat block of *wood, as at C, Fig. r.

When cutting narrow widths, the lino canbe placed on the kitchen table (Fig. 2), butfor the large main piece the work of cuttingmust be done on the floor. Kneel well on thelino and draw the knife along steadily, and,with a firm pressure. A second or third cutmay be necessary before the knife is through.

Headless brads, of tapered square section,should be used for nailing down the linoleum;these brads make it easy to lift the lino whennecessary. There is no need to put in manybrads, as lino tends to lie flat. A neat finishcan be made along the bottom of the skirtingby nailing down lengths of plain triangularwood moulding. This not only covers any

-/Aar"rAp--"11.1111rAmerimmer

:j4w4.4aWArAdrr7*--- 41117

.

Fig. 3.-Marking out a damaged part of lino-leum for removal.

cutting lino.

Odd .Jobs in House and -GardenLaying and Repairing Linoleum Staining and Polishing Floors

By "HANDYMAN"

slight unevenness along the edge of the lino,but also facilitates sweeping and cleaning thecorners.

Repairing Damaged LinoIt is sometimes necessary to repair lino

which has been damaged by heavy furnitureor broken castors. One method is to obtain asound piece of lino to match the damagedpart, which should be carefully removed by

A

C

Fig. 1.-Knives used for cutting lino;and emery -paper block for sharpening.

cutting along the lines of the'pattern as shown in Fig. 3.Using this piece as a tem-plate, cut the new materialto the size required andneatly fix this in place withbrads, punching the headsof the brads slightly belowthe surface of the lino.

Another method is to cuttout the damaged piece andafter removingit slip a newpiece of lino (of larger size)underneath. Shift it

until it matches the pattern properly, andtemporarily fix it with a few brads half drivenin. By carefully drawing the knife along theedge of the hole and through the piece of linounderneath a good fit will result. Remove thebrads, lift all loose pieces of lino out, theninsert the new piece, and finally fix it in place.

Linobrad

Cleaning LinoleumIf the surface is matt, it can be washed

occasionally with warm soapy water. On noaccount should soda be used, as this tends todry out the oil in the material, causing it tocrack. A little linseed oil applied after washingwill act as a preservative.

If the surface of the linoleum has been waxpolished it is only necessary to apply liquidpolish about once every two weeks to keep itin good condition.

Staining FloorsBefore staining a floor it should be properly

prepared by first of all removing all tacks ornails and plugging the holes with plastic wood.All traces of dirt or grease must he removedby washing the floor well with strong soap andwater, followed by dean water. After drying,rub the floor over with a piece of glass paperwrapped round a flat block of wood.

It is usual to stain only the surround, or thatportion of the floor not covered by the carpetor lino, plus an extra 6in. for the edge of thefloor covering to overlap.

There are several kinds of stain that can beused, one of the cheapest being made bydissolving permanganate of potash crystals inwarm water. The stronger the solution thedarker the tone. If the first coating does notgive a dark enough tone another coating can

be applied after the first one has thoroughlydried.

Another cheap stain is made by dissolvingVandyke crystals in warm water, adding toeach pint about I oz. of ammonia, and a littleglue size. This is suitable for a, light oak orwalnut colour, but if a darker shade is requireda mixture of Brunswick black and turpentinecan be used, adding less turpentine the darkerthe shade required. Other water, oil or spiritstains are readily procurable at any oil andcolourman's shop.

Apply the stain with a wide flat brush, andwork with the grain of the wood wherepossible.

A Simple PolisherThe easiest way of polishing is to use a

polisher with a long handle to avoid kneelingdown to the job. Such a polisher can bepurchased, but the simple device illustratedin Fig. 4 will be found to answer the purposequite well, and can easily be made at home.

The base consists of a piece of woodgin. long, 6in. wide and at least tin. thick.This is covered with several layers of oldflannel, to form a pad, and this in turn iscovered with a piece of strong calico, the endsof which are turned up over the wooden base,and secured by brass -headed pins. Screwedto the centre of the top of the base is anotherpiece of lin. wood Sin. by 4in. wide, to the endsof which are screwed two pieces of the samethickness and width, and 21in. wide. Betweenthese pieces another piece of wood (D) ispivoted by means' of two stout iron screws,the two lower edges being rounded, as shownat E. The screws should be driven tightly

Fig. 4.-A simple floor polisher, and detail ofswivel top.

into the part D, but theholes in the part Fmust be an easy fit for the shanks of the screws.One end of the handle (an ordinary broomhandle) has a flat chiselled on one side, towhich one leaf of an iron hinge is screwed.The other leaf is screwed to the part D, sothat the end of the handle comes about thecentre of the polisher. It will be seen thatwhen in use the handle of the polisher can bemoved from side to side as well as backwardsor forwards.

NEWNES ENGINEER'SVEST-POCKET BOOK!By F. J. CAMM 7/6 or by post 8/-

Obtainable from all booksellers, or by post fromGeorge Newnes, Ltd. (Book Dept.), Tower House,

Southampton Street, London, W.C.2.



Toy Manufacture:Principles and Practice

The Methods of Operation,AT the present time, when toyS- are

scarce and only obtainable at pro-hibitive prices, this new series of

articles on Toy Making should prove aboon. Sufficient information is given to enableanyone with a few tools to make simpleworking toys quite cheaply.

There are two main classes of toys-softand hard. Soft toys include dolls andsimilar toys, and hard toys such novelties asclockwork locomotives, tops, steam engines,

aFig. s.-A twisted skein of elastic may be'applied to drive a toy motor -car or any similar

type of runabout toy.

Fig. 2.-A peg passed through the centre of asingle elastic skein enables both wheels to revolve

" in the same direction.

etc. In both these classes are working modelsand non -working models. A further exam-ination of these two classes will reveal that allof them work on a number of well-knownprinciples, employing simple mechanicalmovements. In some toys gravity is theactuating power. In others, chemical actionis used ; wind power, clockwork springs,twisted elastic, steam, and many othermechanical and natural forces are employedto create movement in the toy itself.

Elastic -driven ToysPerhaps the simplest form of motive power

for toys is the twisted skein of elastic. Fig.shows how this may be applied to, drive therear wheels of a toy motor -car. This form ofdrive may be applied either to the front orback wheels. Each wheel has a small hookextension of its axle, and this is connected to asimilar hook suspended from the bottom ofthe car. It will easily be seen that when askein of elastic is connected from each wheelhook to the hooks suspended from the floorof the car, and the latter is drawn backwardsalong the floor, the skeins will be twisted,and when the car is released it will run for -

Fig. 3.-Another elastic -driven toy.The elastic, when twisted, will make

-the toy revolve. in a circle.

Fig. 4.-By twisting theballs in opposite direc-tions, and releasing themon the floor, they per-form a series of amusing

antics.

and Constructional Details

ward. A variation of this idea consistsof connecting both wheels with a single skeinof elastic and passing a peg through theskein, as shown in Fig. 2, which virtuallysplits the skein into two and enables bothwheels to revolve in the same direction.

Elastic -driven BicycleFig. 3 shows another novel toy. Here

the figure of a man is mounted on a bicycle.A pointed peg carries two wire struts connectedto the bicycle, which may be of the penny-farthing variety or a safety bicycle, and a smallbracket carrying a crank hook by meansof which the elastic skein is wound. Theother end of the- elastic skein is connectedto the rear wheel of the bicycle, throughwhich the drive is effected. The figure seatedon the saddle is suitably jointed so that whenthe bicycle is in motion (it travels, of course,in a circle), the limbs simulate the action of areal cyclist.

The Acrobatic BallsFig. 4 shows two fairly heavy balls, with

hooks screwed into each, and connectedby a skein of elastic. By twisting the twoballs in opposite directions the elastic skein

will become twisted,and when the ballsare placed on thefloor they will per-form a series of amus-ing and queer antics.There is one other

Fig. 7.-When the lower end of the string is pul ed- the windmill will rotate at a rapid rate, whistling whilst

doing so. It will also re -wind itself.Fig. 8.-A simple tumbling acrobat, operated by means

of momentum obtained from a revolving flywheel.

peculiar property of the elastic skein whenused in this way. The two balls whenunwinding will, gather considerable momen-tum, so that they will 'overrun themselves andrewind the elastic skein in the oppositedirection, but, of course, not to the same

extent as he initial winding.It will continue to unwind andrewind itself a considerablenumber of times before theinitial force stored in the elasticis finally spent.

Elastic -driven Model BoatsThe elastic skein has of

late years been adopted todrive model boats ; a simplebearing carrying the propellerand hooked propeller shaft,with a single skein of elasticsecured at the bow end of thekeel to another hook, constitutesits simplest application for thispurpose. For larger boats, how-

Fi g. 5.-An amusing elastic -driven swinging toy which,when correctly adjusted,will work for over d quarter

of an hour.Fig. 6.-A detail of theswing boats shown by

Fig. 5.

ever, geared motors shouldbe used to provide greaterpower. The idea hereis to use two separatestrands of rubber geared together so that theymay act on the single propeller. The skeinsshould be arranged so that they are not quiteparallel, which enables the gearing to bereduced in width at the fore end of the boat.The construction must be designed to suitthe size and shape of the v: ss21. The gearingConsists of two spur wheels of equal size run-ning in bearings in an angle plate of sheetbrass and carrying -hooks to which the rubberstrands are hitched. Special gears for thispurpose are obtainable from model aeroplaneaccessory dealers. Clock wheels are quiteunsuitable.Elastic -driven Swing Boat

Fig. 5 illustrates an interestingelastic -driven toy which came onthe market a few years ago. Itconsists of two figures in a swingboat suspended from a cross -arm, rotated by an elastic skeininterposed between two uprightsfastened to a base. Beneath thebase is a small winding crank,which extends through the base,and is crooked at its upper end toengage with the elastic. At theother end of the arm carryingthe swing boat a- piece of twineis fastened, and the lower endof this , carries a small metal ball.It will he obvious that when the

elastic is wound the top arm will revolvefor one revolution. The momentum thusimparted to the string will cause this toswing out and catch on the supplementaryupright fixed to the base for that purpose.the ball will thus twist itself round thisupright, and the check action thus impartedto the revolving arm will cause the boatto swing, and the figures in it, havingjointed limbs, will imitate the action of two

Fig. 9.-A wheeled toycan be operated bymomentum in the man-

ner shown here.'

Fig. 10.-Side viewof the device shown

in Fig. 9.



11

human be-ings opera-ting ' a realswing boat.There arecertainniceties in theadjustmentof this novel-ty to be ob-served beforeit will worksatisfactorily,but the toyonce correct-ly adjusted

'will continueFig. II.-An inclined plane to work formechanism for working clowns, over a guar -

acrobats, and see -saws. ter of anhour. Fig. 6

is a detail of the swing boats.Fig. 7 shows a model windmill _having a

string attached to its spindle. The vanes of thewindmill are set at a slight angle and have asmall whistle attached. The spindle is rotatedby means of the vanes to wind the string uponit. When the lower end of the string is pulled

.the windmill will revolve at a rapid rate,whistlingwhile doingso, and it will

J overrun itself/ and rewind

the string. Bycontinuouslyand altern-ately exer-ting tensionon the stringand releasingtension thewindmill willcontinue to

spin indefinitely. It will be seen that theunderlying principle of this toy is that ofmomentum, which may be applied in manyother ways to operate toys.

Toys Operated by MomentumFig. 8 shows a simple tumbling acro-

bat connected to the spindle of a spinningflywheel. This spindle should be made of thesmallest possible diameter- so that the figuremakes a considerable number of revolutionsbefore it reaches the end of its track. A stringis wound round the spindle to operate it.Small slots are provided at each end of thetrack support to prevent the bgure rolling off.The clown can, of course, be jointed at thearms, knees and hips.

This same motion may be used to drivewheeled toys, such as a motor -car, in themanner shown in Figs. 9 and to. Here thespindle to which the flywheel is attachedextends through the body of the toy and makes

Fig. 12.- T h etype of toy workedby the mechanismshown in Fig. II.

Figs. 13 and 14.-When the soldier is inclinedwith the finger it will continue to sway back-wards and forwards for a considerable time. It

will refuse to lie down. -

contact with the peripheries of the tworear wheels. A small drum is also mountedbetween the two wheels, and string isfound round this. When the string isgiven a sharp jerk the flywheel is set inmotion, and when the toy is placed onthe floor the wheels make contact withthe ends of the spindle, which thusdrives them. Owing to the gear reductionoccasioned by the difference in thediameters of the spindle and the wheels,the rate of progression of the toy willnot be rapid, although the duration ofits run will be about twice as longas the ordinary clockwork toy. Pry

TootWheInclined Plane Toys

A development of this idea, andone which is a decided improve-ment on it, is illustrated in Fig. Ir.Here a wheel with spindle attachedis made to, roll down a series ofinclined planes.. Any number ofinclined planes may be used, andthe ends of the spindle may be em-ployed to drive working models,such as clowns, acrobats, and see-saws, as shown in Fig. 12.

Gravity -operated ToysQuite a number of interesting

toys of the swinging and see -sawvariety may be made, utilisinggravity as the operating force. Forexample, the simplest toy of this type isshown in Figs. 13 and 54. Here the figureof a soldier (or any other figure, for thatmatter) is mounted on a hemispherical baseloaded with lead. When the -figure is inclinedwith the finger it will continue to swingsway backwards and forwards for a consider-able time, owing to its very low centre ofgravity. Another toy working the same on

principle isshown in Fig.15. Here thefigure is moun-ted on a pedestal,and two wirearms, withloaded ballsattached, enablethe figure toswing and swayfor a consider-able time with -o u t becomingunseated fromits perch: Fig.16 illustrates thevaulting horse.Here the weightis disposed a fair

distance behind the point of support of thehorse, which will continue to prance andvault once the weight is set in motion.

awed

elRack dt Pau/1Spiral Spring/

, Alt \ miti I 1 1

11,111ri"I'L

Fig. i6.-The vaultinghorse, employing thesame principle as in

Fig. 15.

Fig. j8.-Elements of a clockwork motor fortoys. It may be made from old clock parts.

SiOringDrum

Brass PinionEngine Frareta

Keepers or DiStance PiecesFlamed Wheels

a -Lead.

Winding!Key -

Fig.

Fig. 15.-A figure which swings and sways fora considerable period without falling off the Fig. 17.-Two figures pivoted between twopedestal, owing to the weights being below the tubes containing mercury will somersault down -

centre of support. stairs in a realistic manner.

Wheel HeldWhilst

Win din,

19.-A simpler typeof clockwork motorusing a helical spring.

An interesting and realistic toy is thatillustrated in Fig. 17. Here two acrobats,both pivoted between two tubes containingmercury, vault down a series of steps in averyrealistic manner. Any number of steps can bearranged ; the figure will continue to work aslong as there is a step for them to tumbledown. The principle on which the toy worksis this : When the figures are placed uponthe tap step, the mercury will run to one endof the tube and lift the hindmost clown offhis feet, thus swinging him over the headof the other clown. The two clownsconnected together by two threads whichcause the figure in the air, when it reaches acertain point, to capsize and to descend uponthe next lowest step. This cycle of operationcontinues until the last step is reached.

Clockwork Motors for ToysThere are two forms of clockwork. toy

motors : that'which uses a clockwork springproperly so described, and that which uses aspiral spring wound upon a drum. Both ofthese types, which are illustrated in Figs.18 and 19, may be made from qld clock parts.In Fig. 18 the various pinions are shown ; x2is a ratchet wheel, 13 is a pawl, and 14 is_thepawl's spring. The first driving wheel isindicated by the figure 1, and the second bythe figure .3 ; 4, 5 and 6 are a pinion and spurwheel. Fig. to is self-explanatory.

(To be continued)



MASTERS OF MECHANICSNo. 83.-Francis Maceroni, the Manchester -born Italian, and his Road Locomotives

fHE engineering student of the presentday may well be excused for probablynever having heard of Francis Maceroni,

since this individual, despite his energeticenthusiasm and originality of mind, was oneof invention's " unlucky ones," and the detailsof his career have lain buried under theaccumulated weight of more than a centuryof mechanical invention and discovery.

Yet Maceroni was a power in his day.Had it not been for the coming of the railways,this pioneer of steam -power application wouldno doubt have prospered and made good forhimself. But because this early inventorconcentrated the majority of his .ingenuitiesupon the production of serviceable steam -powered " road carriages " he sank intoobscurity and even, it is thought, into aprofound state of poverty inconsequence ofthe several. vested interests which, during theearly period of Queen Victoria's reign, well-nigh totally closed the roads of Britain to.anysemblance of mechanically propelled vehicle.

Maceroni's Italian -horn father was in

menter, was making trials with steam boilersand road locomotives. Between 1825 and1828 we find Maceroni helping Gurney toimprove his engines and also to find financialsupport for his inventions. It seems, however,that after a period of three years with Golds-worthy Gurney, Maceroni convinced himselfthat Gurney's efforts would, for one reasonor another, never succeed. And, having thisconviction in mind, he suddenly threw up hisassociation with the Cornish engineer andtook himself off to a no less romantic city thanConstantinople, in which town he appears tohave led merely a wandering, haphazardexistence.

The summer of 1831 saw Maceroni backin London, this time with the idea in his headof constructing a steam " road carriage"which would really run. Similar vehicleshad been designed and constructed in thepast; but the majority of them had had onlyvery short-lived successes, and this lack ofsuccess Maceroni put down principally todefects in their boiler systems.

A reproduction of an early eighteenth century cartoon. It embodies theartist's idea of a steam plough, and was issued to ridicule the use of

steam for locomotive purposes.

business as a merchant in Manchester, andit was in a country house near to that thenprosperous and growing cotton town thatFrancis Maceroni, his engineer son, first sawthe light, in the year 1788.

Of his early years and boyhood, his educa-tion and upbringing, nothing seems to beknown. He first comes into the picture ofhistory in 1814, in which year he was residentin Italy, and had been made an aide-de-campto Murat, King of Naples. .Although only25 years of age, lie held the rank of colonel,and this title, through some whim'or fancy,he proudly retained and used to the end ofhis life.

How Maceroni first obtained an interest in,and 'an insight into, the technicalities ofengineering and mechanics'is quite unknown.Doubtless, however, his early militarycareerhad something to do with his mechanicalleaning.

In 1825 Maceroni moved to London, andapparently sought in that city new interestsand new fields for activity. He chose to be asteam-engine inventor, doubtless in c6nse-quence of his having seen a numl?er of theearly locomotives " in action " and having hadopportunities for criticising their many defects.

At that time Goldsworthy Gtfrney, theCornish engineer and mechanical experi-

Maceroni's BoilerSo, with his head

full of road -carriagesand steam boilers,Maceroni, in con-junction with an in-dividual , namedSquire, invented andpatented what wasinherently a reallyefficient portablemulti -tube boiler forroad locomotive use.

Maceroni's boilerwas made up of 81vertical tubes ar-ranged in nine rowsand with the firegratein the centre. Allthe tubed were con-nected together attop and bottom, thebottom connectionsbeing for water andthe top ones for

steam. From these latter connections steamescaped to a central dome, from which it wastaken to the engine cylinders. There was agood diffusion and economy of heat in thisboiler, and it proved to, be a rapid and anefficient steam generator, its working pressurebeing of the order of .15o lb. per sq. in.

Consequent upon obtaining his patent forthe newly inventedsteam boiler, Maceroni,aided by a few work-men, constructed asteam carriage for useon the public roads.The vehicle carriedII passengers, besidesthe driver, and onehistorian of the timecalled it " a fine speci-men of indomitableperseverance." Thevehicle - travelled atabout 18 m.p.h., the_boiler being fixed atthe rear of the carriage,its two engines beingsecured in a horizontalposition underneath'the body of the carriage. -On the open carriage

body were placed water tanks, and uponthese wooden benches were fixed for thepassengers.

Steam Carriage NoMaceroni's first road carriage was some-

thing of a nine days' wonder. It attractedgreat attention, particularly as its inventorpublicly invited any interested persons toinspect it minutely in his workshop atPaddington.

In 1833, the London Morning Chronicle,commenting upon the success of Maceroni'ssteam carriage, remarked that " this steamcarriage has plied daily for some weeksbetween Paddington and 'Edgeware withoutmeeting with any accident. Since it hasstarted it has trayelled a distance of upwardsof 1,700 miles, yet in the whole of that timeit has not needed any repairs."

Maceroni's steam carriage of 1833 made itsappearance in all parts of London. Som&.times it journeyed from the metropolis as faras Harrow -on -the -Hill, the journey beingcompleted in just under the hour, the famoushill at Harrow being ascended at the rate of7 m.p.h. In the early part of the followingyear (1834) the celebrated carriage was to beseen voyaging, regularly between OxfordStreet, London, and the village of Edgware,and afterwards it made a short series of tripsbetween Regent Street and Uxbridge, adistance of about 16 miles, which was coveredin a little more than an, hour's non-stoprunning.

Usually Maceroni himself presided at theengine controls, but his associate, Squire; wasgenerally the steersman, of the novel vehicle.

Steam Carriage No. 2Encouraged 'by his success, Maceroni

constructed his Steam Carriage No. 2. Thiswas nearly double the size of the first. Itcarried a complement of 16 passengers, inaddition to their luggage. Had Maceronibeen of a more equable temperament, he mighthave made a good thing out of this SteamCarriage No. 2. As matters were, however,he developed one of his periodic fits of rest-lessness, and, towards the end of 1834, hetook it into his head to dissolve partnershipwith Squire.

Left to his own resources, Maceroni veryquickly found himself in extremely lowfunds. In order to raise money, he associatedhimself with an Italian Jew named Asda,whom he allowed to take his two steamcarriages over to the continent. The agree -

A steam coach built by W. H. ames in 1830,


March, 1943

ment was that Asda was to pay Maceroni* £1,500 cash for a share in the steam carriage

patents and, also, that one of the carriageswas to be returned to England within a coupleof months.

From the available contemporary reports,it appears that the two steam carriages didwell in France acid in Belgium. So, also, didAsda. He literally made hay while the sunshone. The French King was prevailed totake a ride in one of the steam carriages, andthat royal personage was so enthralled withthe new experience that he made a handsomemonetary award to the lying Asda, who,incidentally, was villain enough to style him-self the inventor, constructor and owner ofthe steam carriages. Out of 'his continentalexploits, Asda made some £16,000 by sellingthe steam carriages and the continentalmanufacturing rights to a syndicate Of Frenchcapitalists.

At the same time, Maceroni, in England,nearly starved. He did not receive a singlepenny from the rascally Asda, and most ofhis tools and workshop equipment at hisPaddington factory were taken by creditorsas payment for his outstanding accounts.

That was Maceroni's first major dis-appointment. The next one came a couple ofyears later when, in 1837, the year of theaccession of Queen Victoria, he attempted to

A steam -propelled carriage, built by Maceroni, 1833-34.

start a company for the construction of steambuses, and for their running in the streets ofLondon and elsewhere. Maceroni even hadvisions of beginning a regular steam -busservice between London and Birmingham.But the attempt to form the company failed,as did another similar endeavour in thefollowing year.

Railroad CompetitionThe fact was that the public at this time

was in the grip of the " railway mania." Theiron railroads were being cpnstructed allover the kingdom. Capital was being lavishlyexpended in this direction and the railroadpromotors had every reason to discourage theendeavours of steam road -carriage construc-tors to form companies which would give riseto direct competition to their efforts.

But in 1841, owing to the determinationand even, one might say, the obstinacy ofFrancis Maceroni, an enterprise known as"The General Steam Carriage Company"was brought into being, with the object ofconstructing steam carriages under theMaceroni patents. A certain Mr. Beale, anengineer who had works at East Greenwich,was prominent in this endeavour. He demon-strated the ability of Maceroni's steam carriageto run up Greenwich Hill fully laden with 17passengers, and at a speed of 14 m.p.h., and,for a time, lasting success seemed again toappear upon Maceroni's ever-changing hori-zon.

Beale, however, throughout his whole asso-ciation with Maceroni, was mainly intent upon


feathering his own personal nest.Maceronihad contracted . with the new company tosupply his steam carriages at £800 each.After the first carriage had been completedand passed as satisfactory, Beale sent in toMaceroni a bill of costs amounting to f t,too,

201

,Steam Carriage Company went out ofexistence.

Again, Maceroni reached the verge of-starvation. He then endeavoured to combathis bad circumstances by offering for saleoutright the patent rights of his steam boiler,

which rights had then about sevenyears to run. There was no doubtthat this particular boiler had beena highly efficient and successfulone, having >been the means ofpropelling all Maceroni's, steamcarriages successfully, so that, asits inventor hopefully announcedin an advertisement, by the em-ployment of this boiler in asuitably designed steam carriage," a great fortune might be madeon the common roads."

The last of the steam carriage. A steam road -vehicle ofunknown Take of about 1840.

stating that he had included in this chargethe sum of £2o0 for various alterations to thevehicle as a result of its trial trips extendinginto some hundreds of miles. The companyrefused to pay this amount, taking the view

that Beale had madean unjustifiable andan unreason ablecharge. Beale thenretaliated by instantlyrefusing to make anymore steam carriagesand, what was evenworse, by not allow-ing the one carriagewhich had been con-structed underMaceroni's super-vision to go out ofhis works.

In this chapter ofdifficulties Maceroniagain got the worst ofit. Beale remainedadamant, and the

Rival PatentHowever, about this time,

Maceroni's former partner, Squire,the . mechanic and engineer,patented another form of steamboiler. This new patent almost

drove Maceroni frantic, for he insisted bothverbally and in communications to the press,that the Squire boiler was clainly an infringe-ment of his own.

Neither Maceroni nor his erstwhile partner,.Squire, nor even the renowned GoldsworthyGurney, had any more successes with theirsteam boilers and road carriages after about1840, for the railways, in consequence of theirnovelty and of the large amounts of capitalwhich had then been invested in them, heldthe day against all road competitors.

"Maceroni's vexations, justified or unjusti-fied, were all useless. His star was verydefinitely on the wane, and, before long, itbecame all but extinguished. He wrote abook which he entitled Memoirs of the Lifeand Adventures of Colonel Mac,eroni, andperhaps it was this publication which kepthis memory alive for the fewof his life.

Maceroni died in London on July 25th,1846, by which time his steam carriageshad become almost completely forgottenin the excitement of the " railwayfever."

Lord HirstWE regret to record the death of Lord Hirst,

chairman and managing director of theGeneral Electric Co., Ltd., at his home, FoxHill, Earley, nr. Reading, on Friday,January 22nd, 1943, after a short illness. Hewas 79 years of age and until early in Januaryhad been in regular attendance at his office.

Lord Ilirst, who was one of the founders ofthe G.E.C., over 5o years ago, becamemanaging director in 1900 and chairman in1910, and it is in this guise that the worldknows him best as a great industrialist andcontroller of a world-wide organisation withan issued capital of nearly £8,000,000.

The romance of his career and the amazinggrowth of the enterprise he created are apt toobscure the great work he did as adviser tothe State and to industry at large in manycapacities, and the varied interests in life forwhich he always found a place howeverheavily his time was occupied.

Early CareerHugo Hirst came to this country at the

age of 16 and he entered the electrical industrythree years later, but it was not until 1886,When he joined Mr. Byng in what he himselfcalled " a little electrical shop," that his life'swork can really be said to have begun, for thisbutiness was the seed from which sprung theG.E.C.

Mr. Hirst early made up his mind that he

of Milanwas not going through life merely as amerchant, but that also he was going to be aproducer, an industrialist proper, and withthe dawn of the zoth century a manufacturingorganisation with factories in many differenttowns had been created. His aim was then,as always; to make as well as supply " every-thing electrical," and to -day the products ofG.E.C. factories are distributed all over theworld. The G.E.C. was formed in 1889, andthroughout its growth Lord Hirst has beenits inspiration, its dynamic force and its pilot.He so guided the G.E.C. that it grew rapidly,keeping abreast of a rapidly growing industry,and he was still at the helm of the companyat his death. Lord Hirst was one of the firstpeople to realise the importance cif researchin industry, and the company's researchlaboratories are among the finest industriallaboratories in the world-. Many of its staffare scientists and technicians whose namesare known the world over.

In 1937, while president of the F.B.I., hepresided at a dinner given in honour of LordBaldwin, who paid the following tribute toLord Hirst : " . . Lord Hirst is a manwho, by his own ability and gifts of character,has made for himself an unchallenged positionamong the great employers of this country. . . if all big employers in this country weremen of Lord Hirst's character, with his visionand breadth of mind, there would be notrouble in industry."



An Electric Guitar

The completed " eleetric" guitar being- used. in conjunction withthe pick-up circuit of a radio receiver.

PRIORto the introduction of electric

guitars to this country by, I believe,the popular American exponent of the

guitar, Ken Harvey, several systems had beendeveloped for the production of musical tonesby electrical or electro-magnetic means, butnone of them appears to have had any lasting?iiccess. -

It was with the full understanding of thethermionic valve that came the inventions ofthe Trautonium by Dr. Trautwein, the Heller-Lion by B. Helberger and P. Lertes, theSphmrophone by J. Mager, who, incidentally,was one of the first scientists to investigatethe subject, and, as far back as 1929, thenoteworthy work by an Englishman, J.Compton. The latter applied for patentsconnected with what is best described as an" electro-mechanical " system for the produc-titin of musical sounds, as against the generaluse of the properties of a valve as an oscillatorby the other investigators. It is the electro-mechanical system which is now widely usedin conjunction with string instruments andcertain electric organs.

All of the early valve arrangements sufferedfrom the inability to produce chords or aseries of _tones at a given instant ; they werepurely " single -note " instruments, and agood example in this class, and one whichhas been' heard a great deal in this country, isthe Theremin-invented by Professor There-min-which makes use of two oscillators toproduce an L.F. oscillation equal to thedifference between the frequency of the twooscillators; the range of musical tones beinggoverned by varying the capacity of one of thecircuits by movement of the player's handwith relation to a small rod which projectsfrom the instrument.

In all the purely electrical arrangementsthe thetinionic valve was not used only as a_generator of musical frequencies, it was also -employed to amplify such oscillations to thedesired audible volume reproduced vialoudspeakers.

Electro-mechanical MethodsIf a coil of insulated wire is placed around

a pole -piece of a permanent magnet, and ifby some means the magnetic field about thepole -piece is disturbed, an electric currentwill be created in the coil. The strength of thecurrent will depend on various factors ;briefly, the number of turns of wire formingthe coil, the strength of the magnetic field andthe intensity of its disturbance. The frequencyof the current will have a direct relationshipwith the frequency of the diSturbance.

Concise instructions for the Conversion of anOrdinary Guitar to an "Electric" Model, and

the Making of an Electric.One-string Fiddle

A Simple ExampleOne of the sim-

pleSt applications ofthis system to astring instrument isshown in Fig. a,which depicts an" electric " one -string fiddle, which,incidentally, is ideal'

for demonstrating,the basic principleo f the'electro-magnetic system.

The body " d " isa strip of hard wood

By L. 0. SPARKS

magnet of the " U " pattern, its approximatedimensions being tin. in length, On. inwidth and a cross-section of in.

provide a concentrated magnetic field,in the area of the string, and a 'means .ofmounting- the coils " e " and "f," twoextension pieces have to be made. These arecut from transformer laminations, or

x Ain. soft iron strip, the latter being'bent to= form the " L "-shaped pieces asshown in Fig. 2. After filing the horizontalportions to fit the coil bobbins, a tight pushfit being required, the pole -pieces are securedto the ends of the magnet by means of }in.square brass rod and two-one each side ofthe magnet-brass bolts. This method of

fixing was necessary for the experi-mental model, owing to the fact thatthe magnet used did not have anyholes drilled in it in convenientpositions.

The gap " g" is approximatelyC tin., and the unit must be fixed to

the body of the fiddle so that thestring passes along the centre of thegap and parallel to the faces ofsoft iron pole -pieces.

OutputTerminals

Fig. 2.-An enlarged view of the unit fitted to theone -string fiddle. Note the method of fixing.

approximately 3ft. x.iiin. x tin. ; the twopoints " a " and " b " form the anchoringposts for the steel string " s " which passes overthe small bridge " c." To allow the tensionof the string to be adjusted " a" is peg -shaped,and can be rotated in a similar manner tothose used on many string instruments.

The assembly is a skeleton one -string, fiddle ;if -it is played with a bow the volume of soundproduced would be on the low side as nosounding board, box, or horn is fitted. Byusing' the electro-magnetic system thesenormally essential features can be ignored, asone is not concerned with the production ofsound but with the conversion of the vibra-tions of the string " s " into electrical currentsof identical frequency. The conversion isobtained by utilising the simple electro-magnetic assembly shown in Fig: z, Whichfor simplicity we will call the " unit " ; itsposition, with relation to the string " s ".andthe bridge " c" is indicated by " u " on Fig. I.Reference to Fig. 2 will make clear theconstruction of the unit ; " u " is -a permanent

Fixing the UnitThere are two methods of fixing,

depending on the shape and size ofthe, body. If a plain strip of wood isused it is best to shape it so that itis a tight fit between the arms ofthe' " U " magnet and brings thestring in the correct position. Ifoversize holes are then drilledthrough the wood, the clampingbolts can pass straight through,provided short lengths of metal tubeare cut to act as distance piecesbetween the inner faces of thebrass clamping pieces and the outersurfaces of the wooden body, andslipped over the clamping bolts. Theoversize holes allow final adjustmentto be made.

An alternative, and, I think, abetter method, is that which wasused for the second model I made.

Fig. 3. -,--Assembly of the electro-magnetic unit,showing how pole -pieces are clamped to magnet.


March; 1943 NEWNES PRACTICAL MECHANICS 203For this a commercially produced one -stringfiddle of a well-known make -wa'a-used, and ithad a much _deeper body_ at the bridge endto allow for, the fixing -of the horn andknee -grips. (Fig. 1.)

This permitted a slot being cut in the bodyto accommodate the " U "-shaped magnetand bring the horizontal pole -pieces in theircorrect position for the string. The unit wassecurely held on each side by means of twostrips of brass which were fastened to the

"brass clamping pieces and screwed to thewooden body. (See Fig. 2.)

The two coils " e " and " f " were takenout- of an old moving -iron loudspeaker,having a resistance of 4,000 ohms, Lc., 2,000ohms for each coil ; they are- connected inseries on the unit and one wire from eachtaken to the input terminals of an amplifier.

The GuitarJust after completing the electric fiddles,

which, incidentally, originated from an assem-bly made solely to provide a wide range of L.F.frequencies fcr amplifier and speaker testing, Iheard about electric guitars and decided tomake one. As tonal response and- volume of .sound did not matter, I secured a cheapSpanish type of guitar and set about convert-ing it to an electric model.- Unlike the one -string fiddle, the electro-magneticsystem had to embrace six strings,and this presented quite a problemas a- uniform magnetic field aroundeach string was really essential forbest results. Experiments revealedthat it was possible to use one magnetand one large coil, or, two magnetsand one or two coils, but I was notsatisfied with the response obtainedfrom all the six- strings individuallyand collectively. Eventually I devisedthe system shown in Fig. 4, whichprovides a pole -piece and coil foreach string, thus ensuring a 'Mtichmore faithful response anduniform output during all stylesof playing.

The completed instrument wasvery satisfactory, so much so that Idecided to invest in a- hand-niade2o -fret Hawaiian -Spanish guitar madeby John Grey. The fitting of theunit entailed cutting the belly of theinstrument, and I admit I was "alittle- apprehensive about touchingthe beautifully finished woodwork.-However, I need not haveworried, as the appearance of theguitar is in no way marred by thefitting.

B

Fig.The

Fig. 5.-An alternative method of constructingthe sets of three pole -pieces' as explained in the

text.

The original electro-magnetic system was used inprinciple, but modified and improved in detail.

The Magnetic SystemThe permanent magnet was again of the " U "

pattern; its dimensions being 3 in. in -length, 2 1 in. inwidth, and a cross-section of lin. - in. It was producedby- Messrs. Darwin, Ltd., and I understand it wasthen a stockshape. Nearthe top of eacharm of the" U " Was a

in. h o 1 e,which simpli-fied mattersconsiderably asregards fix-ing the addit-ional pole -pieces, as it isimpossible--speak-ing forthe ama-teur- todrill themagnets.

The six pole -pieces were made in two setsof three, and were designed to fit on top of the

b

4.-The magnetic unit for the six -string guitar.additional pole -pieces are assembled and then

bolted to magnet.

extremities of the " U " of the permanentmagnet'as indicated by Fig. 4. The originalsets were cut from the solid, the material beingmild steel, and then riveted to their bed -plates "C" (which were cut from a piece oftin. x sin. angle -iron, each being tin: inlength): Accurate marking off is essential,otherwise the pole -pieces will not- line upwith the strings of the guitar and/or it will befound impossible to slide on the coil bobbins.The distance between pole -pieces shown inthe diagram seems universal, but it would beas well to check the string spacing of theguitar under consideration, before markingoff the metal work. An alternative systemof construction is shown in Fig. 5. Thepoints for the pole -pieces are marked offon a small iron strip iiin. x tin. tin., andthe small slots " D ' cut. The pieces for thepole -pieces, which, incidentally, can be madeout of the waste cut from the angle -ironduring its shaping, are provided with the tongue

E " so dimensioned that it forms the malefitting for the slot. When located, the tongueis riveted over, care being taken to see thatthe pole -pieces are at right angles to the strip.The completed parts are then riveted to thebed -plates as in the other method.

Fig. I.-The secondattempt. This is acominercially. producedone -string fiddle con-verted to an " electric"inode7 by the writer ofthis article: - A' strip ofwood, as described -in thetext, was used for the

- initial experiments.

The fixing of the completed assemblies tothe magnet is by means of the portion " A "and the hole " h " which lines up with thehole in each arm of the magnet, a suitablebolt being used to secure the parts. The hole" B " in the bed -plate is tapped, say, 4 I3.A.,and takes a tin. round -headed nickel -platedbolt, which, in conjunction with the top -plate-see Fig. 6-secures the complete unit tothe belly of the guitar, but more- about that

'later.One important item to watch when fixing

the pole -piece sections to the magnet is theneed for the bed -plate to bed right downon the surface of the magnet. No gap orunevenness must exist between the two faces;otherwise the flux density at the tips of the sixpole -pieces will be reduced considerably.

The Electrical SectionA coil is needed for each pole -piece, and

the more turns, of wire used in its constructionthe better. The limiting factor, however' isthe small space between each pole, but thewriter was able to secure a number of moving -iron L.S. bobbins of the r,000 ohm type,which satisfied requirements as regardswidth and efficiency.

The pole -pieces have, of course, to be madeto suit the bobbin hole ,or slot; therefore, be-fore shaping these parts, it is advisable tosecure the bobbins first, otherwise the pole -pieces might be too large or too small. Thecheeks of some bobbins project beyond theircoils ; in such instances it is often possibleto utilise what at first sight might appear tobe oversize bobbins, by carefully rubbingdown the cheeks, provided the winding is notdamaged. ;

Before and after placing the boh,bins onthe pole -pieces, apply a simple continuity testto make quite sure that the windings areintact. If all is well, they are then connectedin series by neatly soldering the end of onewinding to the start of its neighbour, and so on.See that all joints are insulated so that theycannot short-circuit through any of themetal -work. When this is completed, twowires will remain unconnected (the start of thefirst, and the end of the last bobbin). Theieform the connections for the output of theunit, and they should be lengthened by joiningon, say, r8in, of flexible instrument wire or,even fine twin twisted flex.

Fitting to GuitarThe following figures are given only as a

guide, as many of them will be governed bythe size of the bobbins used and individualconstruction. .With the assembly described,

/Continued on page 2c6`,



The Story of Chemical DiscoveryNo. 20.-The Founding of the Rubber Industry

THE natural -rubber industry, notwith-standing its world ramifications and itsoverwhelming importance in modern

times, is the product of little more than acentury's growth. It was, too, one of the firstlarge-scale industries to be dependent almostentirely upon the application of chemicalscience to its various operations and science.The rubber industry grew up with chemicalscience, and constitutes, in fact, one of theearliest of chemistry's numerous present-dayindustrial offspring.

Early HistoryThe early story of natural rubber is well

known.' Christopher Columbus is supposedto have been the first man to have called theattention of the civilised world to the peculiarand remarkable properties of rubber, for,according to the chronicle left by contem-porary historians, it was during Columbus'ssecond voyage to the New- World between1493 and 1496 that he found the natives ofHaiti playing their tribal games with hard,elastic balls which, they told him, had beenfashioned frOm the flexible gum of a certainspecies of tree.

Among the interesting matters which hebrought'to light was a process devised by thenatives of this part of the world for makingwaterproof garments, bottles, shoes and otherarticles simply by coating thin fabrics with the

Thomas Hancock, the discoverer of vulcanisation.

A rubber plantation in the tropics. Upon these trees the world's supplyof natural rubber depends.

Apart, however, from a single record whichis extant concerning the use in Mexico bySpanish troops of rubber juice for the tinter -proofing of garments, the Old World and itspeoples seem completely to have ignored thepossibilities of natural rubber for close upontwo and a half centuries.

Indeed, Europe's first close acquaintancewith'this naturally elastic product only camesubsequently to 1736, in which year theFrench Academy of Sciences equipped anexpedition to Peru for the purpose of measur-ing an arc of a meridian. After the expedition-ary task had been completed, one member ofthe party, a certain Charles de la Condamine,remained behind in order to indulge hispassion for geographical exploration and, in-particular, to map out the track of the AmazonRiver.

Condamine made many discoveries con-cerning the people'of the Amazon valley.

juice of native trees, andallowing the treated abricsto dry above a smoky fire.

This explorer broughtback to Europe manysamples of raw rubber foranalysis by the Frenchchemists of the day, butthe material defied analysis,and unfortunately it wasfound impossible to trans-port the rubber juice or" latex " to Europe in viewof the fact that it so rapidlysolidified when taken fromthe tree.

This, indeed; was thefact which held up rubberdevelopment and utilisationin Europe for so long a timeafter its first introduction by

The invention

de la Condamine, the. French explorer.During the middle portion of the 18th cen-tury, when the question of discovering a usefor this novel and remarkable product fromthe New World was first mooted, industrialchemistry was almost entirely non-existent.Some chemists, as, for instance, Macquer andHerissant in 1763, suggested that the coagu-lated rubber juice might be dissolved inturpentine, while at a later date it was foundthat ether, a well-known solvent, was betterfor this purpose.

It was not, however, until the last decadeof the 18th century that it was discoveredthat petroleum spirit could be made todissolve rubber.

The First Rubber TubesConsequent upon this important discovery

came the first utilitarian employment ofprocessed rubber. A chemist named Grossartsucceeded, in France, in fashioning rubbertubes by cutting strips from coagulatedrubber, by fieating these in order to softenthem and finally by cementing them togetherby means of treatment with petroleum spirit.

About the same time, another Frenchchemist, Foucroy by name, found that thecoagulation of the natural rubber " milk," orlatex, could be prevented by treating thematerial with a small amount of alkali, andhe went so far as to suggest that large con-signments of the material could' be trans-ported to Europe safely if only it Could bepre-treated with alkali in this manner.

Foucroy's suggestion never materialised,and indeed, surprising as it may seem, it isonly since the conclusion of the last warthat natural rubber latex, stabilised by thecautious addition of ammonia, has become acommercial product in England and otherEuropean countries, the natural -rubber in-dustry evolving itself during the 19th centurysolely upon the utilisation of the coagulatedlatex, that is to say, the " raw rubber " in itssolid form.

"India -rubberDr. Priestley, the famous English chemical

philosopher of the 18th century, the dis-coverer of oxygen and other gases, put

which " made" the rubber trade-Y. B. Dunlop'sfirst pneumatic tyre.



forward the suggestion that this naturalproduct from the Indies should be utilisedfor the rubbing out of pencil marks on. paper.Priestley is usually credited with havingoriginated this suggestion, but, as a matterof fact, it was made in France some yearsbefore he himself became personallyacquainted with raw rubber and its properties.Still, the suggestion of Priestley caught on;and thenceforth the rubbing materialfrom the Indies, or india-rubber, as it wasultimately termed, gradually became acommercial commodity in England.

Charles Goodyear, American pioneer of therubber industry.

The lack of suitable solvents and machineryfor the treatment of rubber were the twofactors which for so many years effectivelymilitated against attempts at the large-scaleproduction and processing of rubber in thiscountry. Indeed, the rise of the rubberindustry in Britain may be said to have beenan unexpected outgrowth from the successfulinception of the coal -gas' industry in thiscountry.

The early exploiters of the coal gas industrywere faced with not a few difficult problems,first and foremost among which was thequestion of the adequate and remunerativedisposal of the large quantities of tarry matterswhich were generated as by-products duringthe manufacture of the gas. It was aboutthis time that street paving with tar first cameinto use, but, seemingly, this early utilisationof coal tar was not altogether successful for,eventually, the owners of gas companies, notbeing able to find a suitable outlet for theirtars, had to develop methods of actuallyusing the material for the firing of theirretorts.

Thomas HancockIn 1815, there lived in London one Thomas

Hancock, who was in partnership with hisbrother, John, as a coach builder. Hancockwas, indeed, a practical genius for, apartfrom successfully designing steam- road -carriages and bringing omnibus companiesinto existence, he was an adept at two or threeother trades, and also evinced a great interestin chemical experimentation. All Hancock'sexperiments were directed towards strictlypractical and utilitarian ends, and one of hisseries of experiments concerned the utilisationof raw rubber which, at that time, wasbecoming available in greater quantities.

It was in 1819 that Thomas Hancock beganhis experiments with solutions of raw rubberin turpentine. These, however, were allfailures, for the turpentine refused to dissolvethe rubber properly and the semblance of asolution which resulted consistently failed todry out effectively.

But despite the apparent intractability of therubber problem, Hancock hit upon the ideaof slicing thin strips from large masses of thecrude rubber ansl by applying these for usein garments, such as gloves, braces, gartersand the like, in which some degree of elasticitywas required. In fact, Hancock actuallytook -out a patent for the utilisation of rawrubber in this manner. It constituted thefirst of the innumerable line of British patentswhich have since been granted in connectionwith the chemical, physical and mechanicaltechnology of rubber and its products.

Hancock's rubberised garments came in fora fair measure of commercial success, so muchso, that their inventor quickly found himselfin the position of having large amounts ofuseless scraps of rubber on his premises whichwere too small for incorporation into garmentsand articles of attire. In order to utilisethese, he designed (after some considerabletrouble) a sort of rubber -mincing machine,which shredded -up the waste rubber andenabled the inventor to press it into a solidblock by means of a suitable mould and heavypressure. -

Rubberised GarmentsAbout the same time, Charles Macintosh,

a Glasgow manufacturer, contracted topurchase for a period of to years all- thetarry distillates from the then newly equippedGlasgow gasworks, Macintosh's intentionbeing to utilise the tar for the production ofammonia. This ammonia process, however,although it was successful, left him with theproblem of disposing of the remainder of thetarry distillates. The idea of using a spiritwhich could be distilled from the tar, andwhich was called "naphtha,"seems to haveoccurred to the mind of Macintosh almostat once. His notion was to dissolve rawrubber in the distilled naphtha and then topaint the reSulting solution on to preparedfabrics in order to make them waterproof.

In his factory at Campsie, near Glasgow,Macintosh was fairly successful with hisrubberised garments. It was not long beforehe became inundated with orders from theGovernment and from various industrialquarters for his new waterproofed material.

Early in 1824, Macintosh opened new worksin Manchester, transferring his manufactutefrom Glasgow to the former town. Mean-while, Thomas Hancock, in London, had beenfurther experimenting with his shredded wasterubber, and he found that this material wasmuch more suitable for the preparation ofrubber solutions than was the original rawrubber with which Charles Macintosh wasworking. Hancock entered into an arrange-ment with Macintosh toy' use the very cheapsolvent naphtha, the latter having previouslypatented the use of the coal -tar naphtha fromthe gasworks in this respect.

The arrangement operated very favourablyfor Macintosh. It enabled him to preparerubber solutions of at least double the strengthof his original solutions. Consequently, theeffectiveness of his rubber -proofed garmentsincreased considerably. The " macintosh "became a household article. A demandspeedily arose for all types of rubberisedarticles, and it was Macintosh himself ratherthan Thomas Hancock who rose to fame asa result.

Up to this juncture, articles of raw rubberwere seldom used, apart from the rubberisedgarments of Hancock. Rubber was employed,for the most part, in thin layers depositedupon canvas or other material, its use in thisrespect being mainly on account of its excel-lent waterproofing qualities.

The demand for rubberised goods was, ofcourse, present in the United States equallyas much as it was in England. In America,one Charles Goodyear, who was originally adealer in agricultural instruments, had himself,among other activities, toyed with the rubber

,-problem. His aim, about the year 1832, wasto make sheets of solid rubber, sheets whichwould be tough and durable, besides beingwaterproof and elastic.

Goodyear was associatedbwith a man namedNathaniel Hayward who had had some ex-perience in connection with the early Americanrubber companies. Hayward had conceivedthe notion (as the result of a peculiar pro-phetic dream, he avowed) that if sulphurwere incorporated with raw rubber the pro-duct would be immensely hard and tough.

VulcanisationGoodyear seems to have been the one to

put this suggestion into actual practice, andto take a patent out on the results of it. He

Making an incision in the bark of a rubber treefor the purpose -of collecting the raw rubber

" milk" or latex.

mixed a certain quantity of sulphur with 'rawrubber and then exposed the resulting productto the warm rays of the sun, whereupon thematerial blackened and became very tough.In 1839 Goodyear made an accidental dis-covery whereby he ascertained that if a smallamount of white lead were present in the rub-ber, the extent of the rubber -hardening or" vulcanisation " was considerably increased.

On this side of the ocean, a similar notionhad occurred to the mind of Thomas Hancock,working away indefatigably in London. Han-cock, like Goodyear, had also been trying tomake large sheets of durable, tough rubber.Somehow or other (it is not known exactlyhow) Hancock hit upon the idea of combiningsulphur with rubber in order to toughen thelatter. He dipped strips of his prepared rubberinto baths of molten sulphur and, to hissurprise and delight, he found that the sulphurtreatment completely changed them in nature,rendering them tough and absolutely non -tacky. Moreover, Hancock found that if hissulphur treatment were prolonged, the rubberbecame converted into a black, horny materialwhich was, unlike the original rubber, quitebrittle. Here, of -course, was the beginningsof ebonite and vulcanite, although Hancockhimself did not develop these materials.

Ten. weeks after Hancock _had lodged hisclaim at the British Patent Office, CharlesGoodyear, of America, put in a similar claim.Naturally, Hancock's claim had priority andconstituted the one which succeeded.- The respective claims of Thomas Hancockand Charles Goodyear to the discovery ofthat most fundamental process of rubber



technology, vulcanisation, has been disputedby technickl historians at great lengths. Thequestion will probably never be settled. TheAmericans naturally claim their countryman,Goodyear, to be the discoverer of vulcanisa-tion (surprisingly enough, little is said aboutHayward, Goodyear's co-worker), while theBritish claim Thomas Hancock as theoriginator of vulcanisation.

It is certain that neither Hancock nor Good-year copied each other. They were trulyindependent- workers who were separatedfrom each other by the then vast expanse of theAtlantic Ocean. Yet by some not infrequenttwist of fate, they both worlted along closelyparallel channels.

The disccivery of vulcanisation, togetherwith Hancock's use of white lead, and after-wards of litharge, as an ". assistant " to theprocess, made possible the production ofdurable articles of solid rubber. The rubberindustry, in these formative years, consoli-

dated itself and forthwith settled down to thedetailed working -out of its processes.

A further advance in rubber technologycame towards the middle of the last centurywhen Alexander Parkes, a one-time Birming-ham locksmith, discovered a " cold process "of vulcanisation which consisted of immersingthe rubber material in a solution of sulphurchloride in carbon disulphide.

The commercialisation of the bicycle and,at a later date, of the motor vehicle, furtherincreased the sphere of the rubber industry.Rubber plantations had been developed care-fully fora number of years. The study ofrubber -producing trees had been carefullyundertaken by a number of English botanists.Hence it was that at the beginning of thepresent century supplies of rubber for thiscountry were adequate.

Modern rubber research still continues.The introduction of various complex organic

compounds into rubber in order to assist andmodify the vulcanisation process is entirely amodern development, and one which willassuredly yet be extended in scope.

Synthetic RubberSynthetic rubber has its many indisputable

advantages, but, at the present time, naturalrubber excels the synthetic product in pointof excellence and durability. Moreover, it islong likely to do so. For this reason, thetemporary cessation of natural rubber supplieswhich the present world war has unfortunatelybrought about must, so far as possible, bemade good with the coming of peace. Naturalrubber is one of the world's truly essentialcommodities. It is one which has enormoustechnical promise, the scope for invention anddiscovery in the realm of rubber being as greatnowadays as it was in the early days of itsnow historic technology.

AN ELECTRIC GUITAR(Continued from page 203).

the aperture shown in Fig. 6 was cut in thebelly of the guitar, about a centre line parallelwith and ;in. in front of the bridge of theinstrument. After removing all strings thewood was cut out-after lightly scribing therequired outline-by drilling a series oflin. holes around the inside of the outline.To avoid possible splintering of the polishedsurface, it is a good plan to go over the scribinglines before drilling with a fine sharp cuttingedge just to sever the top surface and thegrain of the wood. With a sharp chisel, it is

Fig. 6. -The com-pleted electro-mag-netic unit fitted to

the guitar.

then possible gradually and carefully to cutthrough material between the holes, and,eventually, square up the opening thusformed. Do not exert undue pressure dulingany of the above operations, otherwise thereis the danger of cracking the belly.

The top -plate can be cut out of tin. alumin-ium, or, if nickel -plating can be done, brass.Bevel the outside edges and drill the fixingholes to line up with those ("B ") on thebed -plates " C. The top -plate can, ofcourse, be used as a template for marking outthe opening and locating drilling holes on thebelly. I made the holes slightly oversize, toallow final line-up adjustments to be made.

Getting the. Unit InThe circular hole in the belly of the guitar

is, approximately, Sin. in diameter on mymodel, and it did not allow any too much,room for the unit to pass through. This is apoint to be watched, as if the hole is smaller,then it would be advisable to use a shortermagnet.

Before fitting the unit, the twin leads fromthe bobbin assembly are soldered to.a single -circuit jack, and this is fitted into a suitablehole drilled in the foot or side of the instru-ment.

With a little manipulation, the unit is got

into the interior of the instrument ; get thepole -pieces and bobbins up through theaperture, and, with the other hand, placethe top -plate over the bobbins and passone of the round -head nickel -plated boltsthrough one hole in the plate, the belly, and-after locating it-one of the holes " B " in thebed -plate. Don't screw it right home ; justa thread or two will be sufficient until you getthe other screw through the other end.Tighten both gradually, making sure thatthe unit comes into the required position.

The strings and bridge are then refitted,and, if all. is' well, the tips of the pole -pieces

will be., dead underneaththeir respective strings and,approximately, tin. belowthem. After tuning, theelectric guitar is thenready for connection to anamplifier.

AmplificationTo obtain the true ad-

vantages offered by theelectro-magnetic system, itis essential to use a first-rateamplifier and loudspeaker,otherwise results-as regardstonal qualities and faithfulreproduction-will be farfrom satisfactory.

What wattage output isrequired from the amplifier?

This is a question which must be answeredby the player according to his require-ments. For example, for solo and normalplaying in a room of average size, onewould require far less output than theplayer in a dance band performing in a largehall. I have obtained ample output for homeuse from an amplifier having a rated outputof 3 watts ; on the other hand, I have had myguitar played in a super -cinema (by a musician)with only a 5 -watt amplifier and the volumewas quite sufficient. Something around thesefigures, therefore, appear to be the requiredvalue, although, of course, for dance bandwork one must bear in mind the backgroundnoise of the dancers, etc., and the size andacoustic properties of the hall.

I would recommend resistance -capacitycoupling with two triodes in push-pull (ClassA) in the output stage. Two stages ofvoltage amplification preceding the P.P.arrangement. A good make of permanentmagnet speaker is. advisable as it dispenseswith energiging leads and thus gives greaterlatitude as regards its location.

A volume control-o.5 megohms-can beconnected across the output from the unit,and, if so desired mounted on the guitarwithin easy reach of the right hand. Analternative arrangement is to make the

volume control foot -operated, and with thismethod it is not difficult to arrange theoperating device in such a manner that thetremolo effect, normally associated withorgans, can be obtained by a slight motionof the foot. Similarly, a tone -control can beincorporated, but this, I think, calls for carefulconsideration, otherwise the true beauty andrange of the instrument can be ruined byfalse unbalanced coloration. It is far better,at least in my idea, to concentrate on theamplifier and loudspeaker to ensure that theyare good, and get all the effects one requiresb'y playing accordingly.

Owing to the use of the electro-magneticsystem of reproduction, one need not beconcerned with the quality of the guitar ; infact, the six strings could be mounted on apiece of board, and, provided the magneticsystem was arranged as already described,highly satisfactory results would be obtained.Quite a number of American models wereconstructed without any resonating body orbelly, and, so long as the amplifier responded,all was well but, it the latter broke down-andthis is a possibility one has to contend with,though, of course, it is not usual-then theperformer was placed in an awkward position.With the model I have described, one canplay it with or without an amplifier, as thenormal sound -reproducing qualitieS of theinstrument are not impaired in any way bythe fitting of the electro-magnetic unit.

A.C./D.C. CircuitIf the guitar is to be used for band work

or professional engagements, it would beadvisable to use an amplifier designed foroperation off A.C./D.C. supplies, as it is notalways certain that A.C. will be available.One advantage, in addition to that concernedwith the supply of electricity, offered by thistype of circuit, is that it can usually be morecompact and much lighter than an A.C.operated amplifier, especially if an energisedspeaker is used.

Owing to the fact that the chassis or commonnegative line of A.C./D.C. equipment iscommon with one side of the mains, it isnecessary to take certain precautions to protectthe player from the possibility, of shocks atmains voltage. Provided the first valve inthe amplifier has across its grid -cathodecircuit its grid -leak or potentiometer (volumecontrol), the two leads from the guitar unitcan be connected to the grid and earth linevia mica dielectric condensers, each havinga capacity of, say, .00r mfd. to .or mfd.

An alternative method is to use a suitabledesigned transformer between unit and inputto valve, and the component can have aratio of r : r or higher according to thecharacteristics of the unit.

4


March, 1943 - NEWNES PRACTKAL MECHANICS 207

IN the event of a dynamo giving trouble,due to irregular operation, it is bestto tackle this in a systematic manner

to avoid delay in restoring the machine intonormal commission.

Failure to Build Up VoltageSince the initial voltage due to the residual

magnetism alone is very small, a slightamount of resistance may be sufficient toprevent the. passage of current through theshunt field windings, in which case thedynamo will not build up on no load. Thismay be due to sticking brushes, brusheshaving insufficient pressure (the pressureshould, in general, be about 2 lb. per squareinch of brush contact surface), rough or dirtycommutator, or intersegment micas projectingabove the surface of the copper bars in thecommutator. These simple matters shouldreceive first attention.

Dynamo Fault DiagnosisMethods of Dealing with Voltage Troubles

By J. L. WATTS, A.M.I.E.E.

and will melt as the machine builds' up voltage.

Absence of Residual MagnetismShould a dynamo fail to build up after

attention to the points -mentioned, it is possiblethe residual magnetism has been lost from thefield system. This may occur due to mechani-cal shock to the dynamo, the effect of magneticfield from other electrical apparatus nearby,or due to a reverse current having passedthrough the dynamo.

If the dynamo is supplying a motor whichdrives a machine having high momentum, themotor should always be switched off beforethe dynamo is shut down. If the dynamois allowed to slow down whilst still connectedto the running motor it is possible the speedof the motor may fall more slowly than thatof the dynamo, during which period thegenerated back voltage of the motor may be

Equaliser

Equalising Switch

its:leindflgs

frittmpoleWindings

Shunt FieldWindings

Voltage RegulatorNa/

Dynamo

j

Alo.2Dynamo

Fig. 1.-Method of magnetising a _compound dynamo from a parallel dynamo.

Should the voltage regulator be set forminimum volts, the high resistance of thisregulator in the shunt field circuit may preventbuilding up. This should be moved to themaximum voltage position to assist buildingup. It will be understood that if the movingcontact of the regulator does not make aproper connection to the studs the whole ofthe regulator resistance may be connectedin the shunt field circuit. In case of doubtit is a simple Matter to try the effect ofconnecting a piece of wire across the regulatorterminals ; this test may also be used to exposeany open circuit in the resistance units whichmay be preventing field current passing.Wrong brush position may also preventbuilding up. In ease of doubt, the effect ofslight rotation of the brushgear in eitherdirection could be noted.

A method which is sometimes adopted toassist a troublesome compound dynamo tobuild up is to connect a piece of fuse wireacross the terminals of the machine. Thiswire will then provide a low -resistanceexternal circuit through which a compara-tively heavy current can flow due to thevoltage resulting from the residual magnetism.Such current passes through the series fieldwindings, the magnetic field of which willassist the residual magnetism. The wireshould have 'a melting current of abouthalf the full load current of the dynamo

greater than the voltage generated by thedynamo. A reverse current may then flowfrom the motor through the dynamo armatureand any series field coils. The direction ofcurrent through the shunt field coils would beunchanged, but their strength would bereduced by the falling voltage, and theymight then be overpowered by the opposingfield of the series coils and, to a slight extent,the armature.

Similar trouble may occur on dynamosoperated in parallel ifthe voltage of themachines is not ad-justed the same by theregulator before con-necting the dynamo inparallel.

Remagnetisation ofField SystemWhen it is suspected

the dynamo has lost itsresidual magnetism itis best to- test by con-necting a low readingvoltmeter or' low volt-age test lamp acrossthe brushes. If zerovoltage is indicated itwill be necessary to re -magnetise the machine.

Shunt Field Winding

BrushesRaised fromCommutator.

Where compound dynamos are used inparallel the switchboard provides a simplemeans whereby one dynamo can be magnet-ised from another. When the sound dynamoNo. 2 is working on load the single pole switchY on the series field side of the defectivedynamo (Fig. r) and the equalising switch Xcan be closed to allow part of the load currentsupplied by No. 2 dynamo to flow throughthe series field coils of dynamo No. r. Thiswill magnetise the field system of dynamoNo. i with the correct polarity.

An important point to remember in con-nection with a dynamo is that the shunt fieldcircuit should never be broken whilst upwardsof half the normal value of field current ispassing through as this is liable to induce ahigh voltage in these windings. Where asecond dynamo of the same -or a lower voltageis available it could be used to magnetise thedefective dynamo through the shunt fieldcoils. A simple method of doing this isto raise the brushes of the defective dynamo,connect its shunt field winding to the othermachine, and allow the second dynamo toslow down before disconnecting the fieldwindings. This will avoid breaking the fieldcircuit with full current. Should it be in-convenient to alter the speed of the sounddynamo or where a steady voltage D.C.supply only is available, a discharge resist-ance, such as. a few lamps in series as shownin Fig. 2, may be connected across the shuntwindings before connecting these to the D.C.supply. The resistance should not be discon-nected until the supply has been cut off sothat the field circuit is not broken on load.

It may frequently happen that no alternativeD.C. supply is to hand. In this case a battery,which should have as high a voltage as possible,may be used to magnetise the field magnets.If the regulator is set for minimum voltsand the battery connected across it as shownin Fig. 3 the battery may be left in circuitwhilst the dynamo is run up to speed and after-wards disconnected without breaking the fieldcircuit, assuming the dynamo builds up tonormal voltage.

Reversal of Residual MagnetismAfter losing its magnetism it is quite

possible the residual magnetism may bereversed. This may be due to stray magneticfield from other apparatus, reversed currentthrough the machine, or owing to it havingbeen used as a motor.

With reversed residual magnetism themachine should build up voltage in a no. m

Distance Lampsor Resistance

D.0Supply

Fig. 2.-Method of using a discharge resistance when magnetising odynamo field system.


208 NEWNES PRACTICAL MECHANICS March, 194manner, but the terminal polarity of thedynamo will be reversed. This may preventcertain types of voltmeter or ammeter fromreading, but, where a dynamo works on anisolated supply, it would otherwise have noeffect on the power and lighting system, and,in fact, might not be noticed. Where dynamosate used in parallel it is essential the terminalpolarity be correct. In certain cases a motorcircuit may be arranged so that it can besupplied from either of two dynamos throughthe medium of a change -over switch that maybe thrown over without stopping the motoror motors. In this case also the terminalpolarity must be correct, since, during thebrief interval the switch is moving over; themotors will continue to run, and the polarityof the back voltage they generate will dependupon the polarity of the dynamo which hasbeen feeding them. The dynamo polaritywould not matter if the motors were stoppedbefore being supplied by the other dynamo.

Should the polarity of a dynamo becomereversed it is generally a simple matter tochange over the connections at the switch-board to compensate for this.

Load Circuit Faults and Field WindingFaultsIf the test indicates that residual magnetism

is present, the voltage regulator is set formaximum volts, and the brushes and commu-tator are in good condition, and the dynamostill does not build up, the effect of openingthe main switch of the dynamo should benoted. If the dynamo then builds up itindicates that the shunt field circuit is reason-ably sound, and the trouble may be due tothe load circuit having too low a resistance,possibly all the lighting switches may be " on,"or one of the motor starters may be stickingin the " on " position and its switch closed,or there may be a short circuit somewhere.These points should be checked.

A compound dynamo may build up voltageon load, but not on no load. This may betested by closing as many lighting switches aspossible, and perhaps closing a motor switchand holding the starter handle in the runningposition. Alternatively, the terminals of thedynamo may he short-circuited with a fusewire, as mentioned before. If the machinethen builds up somewhat the trouble may bedue to an open circuit in the shunt field circuit,particularly if it still does not build up tonormal voltage. The machine may be buildingup on its series field and running purely as aseries dynamo, in which case the terminalvoltage will rise with increased load current.A simple test of the shunt field coils is toconnect a piece of wire across each coil inturn, when building up of the voltage wouldindicate an open circuit in the coil acrosswhich the wire was connected. The writerhad experience of a dynamo which would onlybuild up on load, although it would thenmaintain' its voltage on no load. This was dueto a small corroded break in one shunt fieldcoil which prevented current passing throughthe coil when only the low voltage due toresidual magnetism was present. After build-ing up on the series field coils the voltage washigh enough to jump across the break and allowthe dynamo to work normally. '

Battery

Should short circuiting the shunt field coilshave little or no effect, and the machine benew to its present duty it is quite likely thatthe shunt field coils are reversed. Theremedy is to change over the connections tothe whole set of shunt coils and note theeffect.

Dynamo Voltage Too LowSince the dynamo voltage is proportional to

magnetic field strength and speed, lowvoltage may be due to reduced speed, possibly -due to slipping belt, prime mover not strongenough or badly governed. This trouble islikely to be more pronounced on heavy loads.After ensuring the regulator is set formaximum volts, and that it is not opencircuited or making bad contact, as may befound by noting the change of voltage when the regulator is adjusted, the speed of thedynamo should be checked.

Overload may be responsible for the dynamovoltage being low, the ammeter reading shouldbe compared with the full load current shownon the nameplate of the dynamo. In some casesit may be found that the dynamo voltage fallsrather a lot after a few hours' run. This isprobably due to bad ventilation allowing thetemperature of the dynamo to rise so that theshunt field resistance increases, and the fieldcurrent falls.

Low voltage will be evident if the brushgearis too far advanced in the direction of rotation,and this will cause an excessive voltage drop

250

0)200

/50

/00g.1.1

50

Fig: 3.-Use of battery to magastise a ((imam?- field system.

0

voltage falls when the coils are short-circuited by the conductor it may be takenthat the coils are correct. If the voltage risesthe coils are reversed, and the connectionsshould be changed over. A short circuit in aseries field coil would cause reduced terminalvoltage on load and would be indicated by nochange of voltage when that coil was short-circuited by the heavy copper conductor.

The voltage of a shunt dynamo is bound tofall somewhat on load, and this is whycompound dynamos are generally used forpower and lighting supplies.

Increased Dynamo Voltage on LoadThis rather rare trouble may be due to the

brushes being set too far from neutral in theopposite direction to rotation and the effectof slight brush movement should first be triedwhen this trouble is encountered.

If the shunt field is weak the voltage of acompound dynamo may rise on load, althoughit may be lower than normal. This troublemay be due to incorrect adjustment or badcontact at the shunt regulator, open circuited,short circuited, or reversed shunt field coils.The methods of locating these defects havebeen dealt with previously.

Parallel Operation of DynamosFor dynamos to operate successfully in

parallel it is essential that they should havethe. same sort of characteristic curve. Forexample, a shunt dynamo in which the voltage

falls with load willnot work in paral-lel with an over -compounded

D No.2 Dl No.2

20 40 60 80 /00 120 /40 /60 /80 200Load Current - Amps

Fig. 4.-Chart indicating parallel operation of shunt dynamos.

on load. The brush rocker may be movedround slightly in either direction, 'and theeffect on the voltage noted, taking care thatthis does not cause sparking at the brushes.

Reduced voltage at all loads may also occurif one shunt field coil is reversed or shortcircuited. A reversed coil is only likely on anewly -fitted machine, and to check this thedynamo should be run with the main switchopen on no load, and a compass needle broughtnear each Tole in turn. The needle shouldreverse its deflection when moved from onepole to the next round the dynamo. If thisdoes not happen the connections to the shuntfield coil having the wrong polarity should bechanged over. To locate a short-circuitedshunt field coil or, in fact, a series coil also, a

suitable voltmeter should be connectedin turn across each coil. A coil show-ing an abnormally low reading isshort-circuited internally, and in needof expert attention. A short-circuitedshunt field coil is generally cooler thanthe sound coils.

In some cases a reduced voltage onload of a compound dynamo may bedue to short-circuited or reversedseries field coils. To check this thedynamo should be run on load, and aheavy copper conductor used to short-circuit the series field coils, makingquite certain the coils have been .identified correctly. If the dynamo

dynamo which hasa rising voltageon load.

Curve AB inFig. 4 shows therelation betweenthe terminal volt-age and loadcurrent of a shuntdynamo, No. r.Curve CD showsthe relations fora second dynamoNo. 2. On a totalload current of120 amps. it isseen that theterminal voltage

of dynamo No. t when carrying 49 amps.is the same as that of dynamo No. 2when this carries (12o ---49)=7L amps., andthe dynamos will automatically share theload in this manner. On a total loadcurrent of 200 amps. the terminal volt-ages will be equal when dynamo No.carries 8o amps. and dynamo No. 2 carries(200-80)=120 amps. so that the load willbe shared thus, the circuit voltage beingslightly lower than before.

If it is desired that dynamo No. r, forexample, shall carry a greater proportion ofthe total load its shunt regulator can beadjusted so that it has a greater voltage atall values of load current. The curve ABin Fig. 4 will then be raised so that thecharacteristic curves of the two dynamos willintersect moreio the right, and dynamo No. 2will automatically take a smaller proportionof the total load, whatever that may be.Shunt machines with similar characteristiccurves should, therefore, carry the sameproportion of the total load without adjust-ment of the regulators, and form a very stablecombination. When shunt machines do notoperate well in parallel, and the regulatorshave to be adjusted to make them take thesame share of the total current when thisvaries, this may be due to one machine havinga greater drop of voltage on load than theother dynamo, possibly due to the brushesbeing too far advanced.


March 1943 NEWNES PRACTICAL MECHANICS 209

With compound dynamosspecial pre-cautions are necessary for parallel operation.If the voltage of one machine falls, for anyreason, the other dynamo may tend to send areverse current through its series fieldwindings. This would reduce " its fieldstrength and voltage still further, so that thesecond machine would tend to take over allthe load. In any case the constant, or rising,voltage of a compound dynamo on increasedload may cause the ratio of load sharing tovary considerably for slight changes of totalload. To avoid these troubles an equalisingswitch, as shown in Fig. r, is used, whichconnects the series field windings of the twomachines in parallel, and this ensures thatcurrent always flows through the serieswindings in the same direction. The circuitbreaker also is generally fitted with reversecurrent trips which will trip the breaker and

disconnect a dynamo if its voltage falls toolow. Bad operation of compound dynamosin parallel may be due to wrong brushposition or to the series field windings of onedynamo being stronger than on the othermachine. In the latter case the strong seriesfield coils could be weakened slightly byconnecting a diverter resistance in parallelwith the strong 'series field coils so thatthey carry a reduced current on a givenload.

When any dynamo is started up and isto be connected in parallel with a dynamowhich is already in operation, the voltageof the incoming machine must be adjustedthe same, or very slightly higher than thatof the running machine before closing theswitch to connect the dynamos in parallel.If the voltages are much different there willbe a considerable rush of current in one

direction or another when closing the switches.When the switches are closed the regulatorof the incoming dynamo can be adjusted totransfer the required amount of 10,4 currentfrom the other machine. When discon-necting a dynamo which is working in parallelwith another dynamo, the regulator shouldbe adjusted to reduce the load on the out-going machine practically to zero beforeopening the switch ; this is advisable to avoidsparking which would damage the switchcontacts when this is opened.

In the case of a compound dynamo whichis to be connected in parallel with a runningmachine, the switches X and Y of dynamoNo. 1 (Fig. 1) should first be closed and thecircuit breaker Z closed after the voltageof the incoming dynamo No. I has beenadjusted the same or very slightly higher thanthat of the running machine.

The Steam CarIN connection with' the above subject, we

have received the following interestingletter from Mr. J. W. Dodds, of

Harborne, Biriningham" I have read the article by W. J. Roberts

in the January issue Of PRACTICAL MECHANICSwith very great interest. There are one ortwo points, however, I would like to bringto the attention of your readers.

" Firstly, one of the earliest, if not the first,makers of steam wagons was LeylandMotors, Ltd., and they only discontinuedmanufacture about 1924. I was their worksmanager at Chorley, where these wagonswere made, and our last experimental vehiclewas well worthy of notice. It was made froma standard petrol 5 -ton vehicle chassis. Afield -tube boiler with exhaust feed waterheater and coil superheater was fitted andthe working pressure was 28olb. per sq. in.

" The engine was a four -cylinder, twin -opposed, single -acting horizontal on twocranks, with poppet valves and a slidingcamshaft with variable cut-offs.

" I append a list of consumption figuresobtained from this vehicle which may proveof interest.

" Secondly, the above -mentioned articledoes riot refer to what I consider to be thebest steam car produced at any time.- " This was a French make called the

Gardiner Serpollet, from which I copied theengine we produced at Leyland.

" This engine was so small and compactthat it could be accommodated under thefloor, and was no longer than a modern cargear -box.

" I am one of the small band of peoplewho have ridden in White, Stanley andGardiner cars, and from the experiencegained I would exchange cm Chrysler at oncefor a really sound steam car.

" The limitations of the early steam carswere mainly due to boiler trouble, and I amsure, with the much more suitable materialsat our_ disposal to -day, and also developmentsin such things as thermostats, etc., a verygood job could be put on the -market.

" The following list of figures was taken onthree types of steam wagon.

" The Sentinel boiler will be familiar toreaders, and that on the Leyland F2 was fittedwith internal curved tubes, which curvedfrom holes at the lower end of the fire -box tothe upper-all round the inside.

" They used to silt up quickly, and had tobe removed for cleaning. The Thimble tubeboiler was developed and was tried out, andits trial coincided with Clarkson's patents.

" The Thimble tube boiler correctlydesigned is self-cleaning, and all sludge collects

in the bottom of the boiler, and can be blownoff."

Particulars ofrun fromChorley to

London withStandard F2Steam Wagon

and fitted withnew diagonal

water tubeboiler.T. C.

Gross weight ofwagon leavingworks .. .. 1I 5 0

Weight of wagon(fuel and water) 6 to .o

Weight of load .. 4 15 0Miles run 240Running time ..Average speed ..Total weight of

water used ..Water used per mile 42.7 lb.Water used per

gross ton mile .. 3.8 lb.Water used per use-

ful ton mile .. 91b.Total weight of fuel

used - 13344 lb. 328 lb.Total weight of fuel

used per mile .. 5.6 lb. 5.38 lb.Total weight of fuel

used per grosston mile 498 lb. .5o lb.

Total weight of fuelused per usefulton mile 1.18 lb. x. ro lb.

Water evaporatedper lb. of fuel . : 7.62 lb. 7.041b.

Gross ton miles .. 2,70oUseful ton miles .. 1,140These figures include fuel Conditions : Roadsfor lighting up on three dry, but atmos-occasions. phere humid.Note : Horizontal double- Route : Hilly andaction engine, two cylin- tortuous, max.ders 41 x 6in. stroke. gradient about IFinal chain drive to rear in 8. -

wheels on each side. Diff. Fuel : Gas cokein engine case. from BirminghamGas coke. and Chester.Test Run' Steam Wagon Fitted with

New Type Engine

Test taken on a" Sentinel

Steam Wagon.(Extract fromCommercial

Motor, Oct. 4th.1921).

T. C. Q. L.Q.

10,220 lb.

II 5 2 14

4 18 0 061

4 hrs. i min.15.19 m.p.h.

2,310 lb.37.96 lb.

3.54 lb.

7.73 lb.

Thimble tubeboiler. Bottom

Horizontal twin -opposed single- superheater.action engine, 41in. by 6in. stroke. Bottom row of

Gas Coke. tubes removed.airl. I arge

diameter tubes.T. C. Q.

Gross weight of wagon leaving.works .. 12 2 2

Weight of wagon (fuel and water)Weight of load ..Miles runRunning time-hours and minutesAverage speed-miles per hour..Total weight of water used ..Water used per mile ..Water used per gross ton mile ..Water used per useful ton mile..Total weight of fuel usedTotal weight of fuel used per hourTotal weight of fuel used per mileTotal weight of fuel used per

gross ton mile ..Total weight of fuel used per use-

ful ton mile ..Water evaporated per lb. of fuel.Gross ton miles ..Useful ton miles ..Extract from The Commercial

December 7th, 192o.Coal v. Oil Fuel for Steamers

The Editor, The Commercial Motor.SIR,

My attention has been called to the letter -in your issue of November 16th, 1920, andyour added note.

It is our constant policy to -understatethe performances of our wagon, and this hasresulted in our having so many satisfied users ;but it is only fair to the writer of the letterreferred to that we should state that consump-tions as low as 4i lb. of suitable Welsh coalper mile are not unusual. It is also our policy,with a view to conserving the national fuelsupply, to advocate the use of coke, and Igive below results of tests run recently withthis fuel, on an average course of 6o milesout and home from these works, over second-class country roads. Test No. I.-6.7 lb. per mile. Ordinary gas

coke.2.-6.65 lb. per mile. Ordinary gas

coke.3.-6.2 lb. per mile. Ordinary gas

coke.4,4.79 lb. per mile. Better class

coke.5.-5.6 lb. per mile. Gas coke.6,6.6 lb. per mile. Gas coke.

(Roads very heavy after rain.)7.-6.4 lb. per mile. Gas coke..8.-5.7 lb. per mile. Ordinary gas

coke. -

We will be very pleased to run a test foryour representative at 'any time you arrange,and he will also have the opportunity oftesting the coke for comparison with Welshcoal, when we have no doubt the figuresmentioned by your correspondent will befound fully possible.

Yours faithfully,The " Sentinel " Waggon Works (192o), Ltd

G. Woodvine, Works Manager.

6 136 o 3

221.30

14.385o lb.39 lb.3.2 lb.6.4 lb.Ito lb.

73.32 lb.5 lb.

.414 lb.

.828 lb.7.73 lb.

266133

Motor of


210 NEWNES PRACTICAL MECHANICS

THE WORLD OF MODELS

Streamlined S.R. engine " Orient" leavingWaterloo Station after her naming ceremony.

Pyruma Modelling ExhibitionWHEN I wrote of Pyruma in this journal

last September I little thoughtit would develop into so universally

popular a modelling material as it undoubtedlyhas. '

One useful item to remember is that thereis as yet no restriction on supplies, it is easilyobtainable, and skilful and enthusiasticmodellers have been able to introduce somany varieties of Pyruma modelling on bothsubject and finish.

This was wonderfully demonstrated at anexcellent exhibition organised in December byMr. Herbert M. Sankey, of Messrs. J. H.Sankey and Son, Ltd. (the makers of Pyrumaand its allied products).

The "Pyruma " Modelling Exhibition wasdisplayed in a large showroom and consistedof over 4o models,6o per cent. of which weresubmitted for exhibition only, the remainderforming the " Pyruma " Modelling Competi-tion, which was judged by two experts, Mr.W. J. Bassett-Lowke, M.I.Loco.E., managingdirector of Bassett-Lowke, Ltd., and Mr.George Sell, managing director of A. D.Services.

Professional ModelsFirst, to mehtion the " professional "

models as apart from " competitors." The

March, 1943

By "MOT I LUS"The Development ,of e NewModelling Medium Britain's

Latest Streamline Trainview, was the model Stallion, finished in thenatural Pyruma, which had the appearance ofbeing hewn out of stone. Others whichcaught my eye were the figure of a HomeGuardsman in the bronze finish, a penguinfamily in natural colours, and a black shinyseal balancing a painted ball on itrnose.

In one exhibit of a model villa, the work ofMr. Caplin, every brick and tile had been

separately moulded. Apart of the roof and floorwere left unfinished toshow the method of con-struction. The scale ofthis model was tin. tothe foot.

Actually the exhibitionwas arranged in sections,under the headings of" Utility and Decoration,"" Animal Models " and" Architecture and Gen-eral," but the exhibitswere so varied-rangingfrom houses to necklaces-that precise cataloguingmust have been an im-possibility.

There were a largenumber of visitors, and Iam sure that many were soimpressed that they willsoon be "trying theirhand " at modelling in thisnew material as a war -timehobby.

Exhibition model of stained' in natural

great point about them was the highlysuccessful manner in which they demonstratedthe variety of finishes that can be achievedin Pyruma.. Some of the models appeared tobe carved in stone, others of highly glazedpottery, some of tinted metal, and one evenlooked as though it were modelled in bronze !

In my opinion, the most attractive pro-fessional model, from the artistic point of

finish "Mirror Grange"Now we come to the competitors. The first

award was outstanding-a model of an oldcountry house, the " Mirror Grange." Itwas a delightful piece of craftsmanship, andone which showed in the best way the uni-versal application of Pyruma as a modellingmedium. This was the work of Mr. Sankey'sson, Donal, and is a " holloiv " model, madeentirely of plastic Pyruma, rolled into flat

A Pyruma villa, by Mr. Caplin. In the foreground will be seen the mould" for .making'the miniature Pyruma bricks.


Of

March, 1943

sheets, cut to sections, and scored with a pen -k knife to represent the various finishes of

brickwork, timbering; tiles and thatch: Itwas then baked and jointed with Tiluinacement. The finishing touches when com-pletely dry were achieVed with poster paint.Readers will remember the illustration of"Mirror Grange" appearing in last month'sPRACTICAL MECHANICS.

Award No. 2 was the work of one of thefair sex, Miss HubBard, and her model wasof a crinolined lady. As you will see fromthe illustration, she has most successfullyportrayed the daintiness and detail of thedress. Altogether it is a delicate piece ofmodelling; and well finished.

Miscellaneous ModelsFor Award No. 3 we enter the " Animal "

section and chooie a fearsome -looking monster-the gorilla. This bears close inspeetion asregards detail, particularly in the gorilla's face,and was the work of Mr. Hext.

Award No. 4 was of a humorous characterby Mr. J. Tyler and formed a novel ashtrayand match -holder under the title of " TopHat and Tails."

Book -ends are always a favourite subjectfor model makers, and here again Pyruma isa suitable medium, as, in addition to it'sother qualities, it also provides -weight. Thetwo book -ends by Mr. F. Jones, with figuresof monks on them, well deserved the fifthaward.

A lighthouse by Miss Blythe gained AwardNo. 6, and was another indication of theadaptability of Pyruma.

The special award went to Mr. Malpas fora colourful and decorative galleon wallplaque, which, had it not been for a technicalerror, which caught the eagle eyes of the

The ,winner of the special award-a galleonwall plaque by Mr. Malpas.

judges, would have gained for its designer anaward much higher up the list. Actuallythe bowsprit was foreshortened and shouldhave been carried much higher, allowing morespace for the ropes carrying the foresail,jib and flying jib. Apart froln this error, theplaque was a very fine effort.

Mr. George Sell was a complete newcomerto the world of Pyruma, so his remarks willno doubt prove enlightening to readers.

" When Mr. Bassett-Lbwke asked me tocollaborate with him in the judging of aPyruma Modelling Competition," said Mr.Sell, " I was, I must admit, somewhat doubt-ful as to what I was going to see. But whenI arrived there I was definitely amazed, not


only at the scope of the models,but the detail' that can beobtained in this meditun: The 'collectiOn - of models;- as awhole, was a most fascinatingand beviildeting exhibit forany judge to Set about, and wehid a most difficult task todecide the merits - of theindividual entries."

Streamlined S.R. Locomo-tiveA friend, -who used to be very

keen on making models of thelatest types of locomotives ofthe various British railways,.complained to me recentlythat very few pictu,res havebeen published of the newstreamline Southernlocomotive.

I received from the SouthernRailway the other dfiy anexcellent view of the engine

A crinolined lady, a Pyruma model by MissHubbard, which gained award No. 2.

" Orient " leavifig Waterloo Station afterhaving been named by Mr. J. C. Geddes,

211

The gorilla, by Mr. Hext, a realistic model,which was awarded third prize.

. chairman of the Orient Line, and ColonelGore Browne, deputy chairman, -Post-war Modelling

I am hoping that when the war is overnot only will model railway engineers wantto make a model of this latest streamline pro-duction f(ir their own railways, but 'thatcommercial firms will also produce modelsfor those who own and. run railways, but havenot the facilities for making their own models.

Incidentally, there are probably manyreaders who, at some time or other, have mademodels of locomotives, rolling stock, orvarious -types of stationary steam engines,photographs of Which have never been pub-lished. Such readers are asked to send alongphotographs, together with a short descriptionof their models, to the Editor, with a view toinclusion in. these notes.

A CORRECTIONIn the article " The World of Models

which appeared in the January issue, thecaption given under Fig. 8 (page 139) refersto the model loco. illustrated in Fig. 9, andvice versa.

Books ReceivedN.C.U. Diary for 1943. Published by the

National Cyclists' Union.THIS handy little diary, of vest-pocket

size, contains, in addition to a fourdays to a page diary, much useful informationfor cyclists. There are also sectional mapsof the British Isles showing the main andtrunk roads.

Marine Radio Operator's Guide. ByH. E. Chamberlain. Published byHutchinson and Co. 72 pages. Price5s. net.

THIS handy volume is intended to supple -merit the training a marine radio

operator will have received before obtaininghis P.M.G. certificate. The author has hadseveral years at sea as a radio operator, andin this book he has collated a large collectionof hints and tips which should be of great helpto the young operator who has yet to servehis sea apprenticeship. Not only does thebook deal with technical problems, it alsotells the newly fledged operator what to buy

in the way of kit and equipment, and whatto provide in the way of comforts and medi-cine. The book contains several goodillustrations of typical" radio equipment onboard ship.

" Procedure Handbook of Arc WeldingDesign and Practic' 7th Edition.Published by Lincoln Electric Co.1,267 pages. Price tos.

SINCE the publication of the sixth editionof. the above book, the appliFation of

electric arc welding has become a leadingfactor in speeding up war production, andconcise, up-to-date information is now moreessential than ever before for executives,works managers, draughtsmen, welding fore-men, welders, and the ever-groWing numberof trainees. elding equipment, procedures,speeds and costs, methods of testing, weld -ability, design and applications are all dealtwith in the new enlarged edition-pricelos. post freeein the United Kingdom, Its.Overseas. The " Fleet -Fillet " Section isalso of particular interest.

The address of Lincoln Electric is WelwynGarden City, Herts.



Our Busy InventorsThree -dimension PicturesA VERY 'interesting invention is one which,

it is asserted, furnishes a third dimensionin the picture on a screen. We are allfamiliar with .the flat picture which haslength and breadth. I understand that,some years ago, the principle of the stereoscopewas utilised to cause on the screen the effectof figures and objects which stand out. Butthis, I believe, was produced by an opticalinstrument worn before the eyes. The newdevice, however, provides a screen which, itis stated, itself displays the illusion of apicture possessing depth in addition to lengthand breadth.

The screen in question has a thickness oftransparent material and a background of asubstance which reflects very little light. Inthe front of the transparent material there isa translucent substance.

Preferably the screen is formed with ahollow curve across its front surface. Thiscurve, is part of a circle of which the radius isequal to the width of the screen. As aconsequence, the light rays of the beam fromthe projector strike the display surface atright angles or approximately so. Therebydistortion of the matter projected is avoided,or reduced.

The transparent material of the screen canbe ordinary refractive glass, but preferablynon -brittle such as a transparent plastic orresin - capable of being curved, cut andotherwise. worked.

If this device lives up to what is claimedfor it, it should prove an attractive adjunctto the cinema.Anti-aircraft Missiles

ARECENT invention relates to a pro-jectile which is designed to be fired

from guns and howitzers, and which, itsinventor affirms, would be particularly effectiveagainst enemy aircraft.

This projectile has a casing packed with amultiplicity' of detached missiles. The casingcomprises a one-piece nose cap at its frcintend and a one-piece base cap at its rearend. The wall of the casing is built up of anumber of longitudinally divided portionsextending between and held together by thenose cap and the base cap,

The nose cap is arranged to be forcedforward from engagement with the front endsof the wall portions by means of a lightseparating charge just behind it. This isexploded by a fuse at a given time intervalafter firing. The connection between therear ends of the aforementioned portions andthe base cap is such that, as soon as the wallportions begin to spread at their front endsconsequent upon the nose cap being forcedoff, they free -themselves from the base cap.As a result, the whole projectile is separatedinto its component parts of nose cap, basecap and wall portions.

The contents of the casing are missiles inthe form of hexagon section rods. These, assoon as thecasing separates as stated, spread,together with the wall portions, by virtue ofthe centrifugal force arising from the spinningof the projectile. At the same time, the nosecap, base cap, wall portions and hexagonrods continue to move forward and a largeportion of space is traversed by them.For the DeafA PORTABLE appliance for aiding the deaf

usually consists of a microphone, one ortwo headphones with or without an arrange-ment for the conduction of sound through the

.11

By Dynamobones of the head, and a primary battery toSupply electric current at a voltage suitablefor feeding the microphone. The apparatusmay include an amplifier.

The British Patent Office has recentlyhad submitted to it an appliance of this kind,which comprises the microphone and head -

The information on this page is speciallysupplied to " Practical Mechanics " byMessrs. Hughes & Young, Patent Agents, of7, Stone Buildings, Lincoln's Inn, London,W.C.2, who will be pleased to send free toreaders mentioning this paper a copy of theirhandbook, " How to Patent an Invention."

phones above mentioned. In addition thereare a smoothing choke in series With themicrophone, feed intake, and one or moresmoothing condensers in parallel with theintake and the choke. The whole apparatusis adapted to be connected to the currentobtained by transforming and rectifying thelatter from an alternating current mains. Anamplifier may be added.

Improved Milking ApplianceTHE mechanical milkmaid, if one may so

term the modern machine whichextracts the lacteal fluid from cows, hasbecome a feature of agricultural life. Butalthough we associate it with cows, it is alsoavailable for the milking of ewes and goats.

It appears that the milking of these smaller'animals presents some difficulty. The normalyoking means employed in the case of thecow is not suitable for the ewe and the goat,which are capable of jumping a considerabledistance from the ground. If there is anyrestraining means above their heads, theymay suffer injury. However, it is imperative

yoking bars capable of being adjusted to aposition allowing the animal's head to passcomfortably between them and also to aposition preventing the head from passingthrough them.

For 'Training Air PilotsA METHOD of teaching on the ground the

flying of aircraft is the subject of anapplication for a patent in this country. Theobject of this system is to train the pilot tomaintain his aircraft at a predeterminedaltitude to the horizontal, or to another air-craft. By this means the instinct of the beginnerto judge his altitude by looking at the groundis counteracted. As a consequence, the correcthabit is acquired from the start.

The new ,invention is especially, thoughnot exclusively, advantageous in connectionwith gliders and ground trainers. It is alsobeneficial in the case of power aircraft whichhave no engine in the nose. Consequently,these machines possess no structure at or neareye -level.

According to the device,- an instrumenthas a pair of horizontally spaced sightsmounted adjustably vertical in relation to thepilot's seat.

Near this seat there is a pillar upon which abracket is slidably mounted. This bracket isadjustable along the pillar and clamped bymeans of a bolt in any desired position. Thereis also an index co-operating with a scale onthe pillar, so that the device can be re -set atany height.

Cigarette RollerANOTHER recent invention is a. simple

cigarette -making apparatus.The new device consists of a tube having a

In this Indian steel works, plates are being.handled by powerful electric magnets.

that they should be yoked in order to preventthem from turning round and from backinginto the stall. These animals must be soyoked that their heads are free to turn withoutdiscomfort and to move in an upward directionwithout causing them injury.

A milking stall for these creatures is thesubject of an application fora patent in thiscountry. It has side walls and a door at itsfront end. This door consists of a pair ofgates hinged to the walls and opening inopposite directions. The door is fitted with

movable section which can be opened to allowthis tube to be filled with tobacco from alateral direction, or sideways.

When the movable section is closed, theexterior of the tube is designed to enable oneto form a cigarette paper into a cylinder.Provision is also made for simultaneouslysliding this paper cylinder off the outside of thetube, and extruding therefrom tobacco end-wise. Thereby a cigarette is made as thepaper cylinder and the tobacco are ejectedfrom the appliance.


March, 1943 NEWNES PRACTICAL MECHANICS

QUER1ES4at4ENQUIRIESA stamped addressed envelope, three pennystamps, and the query coupon from the currentissue, which appears on back cover, must beenclosed with every letter containing a query.Every query and drawing which is sent must -

bear the name and address of the reader.Send your queries to the Editor, PRACTICAL-.MECHANICS, Geo. Newnes, Ltd., Tower House,Southampton Street, Strand, London, W.C.2.

Steam Heating for RoomsIs it possible to heat a large bed -sitting room by

a steam radiator from the fireplace alreadybeing used, but which only heats within a 2ft.radius ?

Could not a small boiler be placed at the backof the grate and connected up to a radiator placed*in the coldest and most draughtiest corner ofthe room ? Would the hot water installation ofan eight -roomed house, supplied from the kitchenfireplace, be sufficient for the use of four or fiveradiators about the house ?-Percy Nava (Black-pool).T0 instal a steam -heated radiator, the steam being

generated by an ordinary coal fire in a bedroom,or a boiler placed at back of such fire, is impracticable,owing to the cost involved. Steam heating by ordinarysystems necessitates steam under certain pressure, andthe installation cannot be considered simple as viewedfrom your standpoint, which evidently does not call fora great expenditure.

If a water -heated radiator is required to be operatedfrom a small boiler placed at the back of the ordinaryfire, a complete heating system on a small scale wouldbe necessary. The system would require a hot watertank, with cold water supply, expansion pipe, and properflow and return pipes to the radiator. All this would becostly, and it is probable that a " good " fire would beessential, to generate the necessary heat.

Without knowing the size of the existing boiler inthe kitchen and its heating duties it is not possible tdstate whether it would be capable of supplying adequateheat to four or five radiators. Unless the boiler is 'ofabnormal power for its present duties it is safe to statethat it is almost certain to be quite inadequate for theadditional heating. Radiators heated by water must bedesigned with utmost care with proper circulating loops,and it is probable that any radiators situated on the samefloor level as that on which the boiler is placed willmake it essential to cause the return pipe on the circulat-ing loop to enter the boiler at a low level to ensure agood circulation ; this requirement, although notalways necessary, may mean placing the boiler a certaindistance below floor level. Another matter of importanceis that it is not good practice to feed radiators off thedomestic supply, as by doing so there is a constantchange of water which will eventually cause furring upof the pipes. The indirect or calorifier system is muchbetter, as the hot water is not constantly changed, butused over and over again, the only loss being by a littleevaporation.

From the foregoing it will be evident that you shouldconsider the matter most carefully and study thepossibility of other methods of heating, such as gas orelectric fires. If hot water heating is necessary then it isadvised that a local heating engineer be consulted.

Spot WeldingIWOULD be much obliged if you could give me

some information on a six -volt D.C. electricwelder to weld up to 20g. with bare electrodes.I believe such a tool is very popular in America,but I cannot get any actual particulars on how toconstruct one. I believe it runs from a six -volt carbattery.-W. R. Williams (Newdigate).'T`HE fusing current of a No: 20 S.W.G. copper wire

A is about 7o amperes, but as you do not state thematerial of which the wire is composed it is difficult toadvise definitely. We think you refer to a " spot-welding " device, however, and not to the arc -weldingprocess ; in which case there is no reason whatever tomake up a transformer provided the 6 -volt accumulatoryou propose using has a sufficiently high dischargecapacity in amperes, such as a starting battery from alarge car. All that is needed is a pair of heavy copperclamps hinged like the jaws of a vice attached to a shortlength of copper flexible, such as 637/..nto or equivalent,lightly braided or insulated, with heavy terminal lugsfor attachment to the accumulator. The clamps aresecured to the wire you wish to weld, at a short distancefrom the welding point, and the wires brought intocontact to form a " butt " weld. A foot switch incircuit with the flexibles is a convenient way of interrupt-ing the current while both hands are engaged.

Tempering of Motor -car Road SpringT WOULD be glad to know how to correctlyA " temper " a spring leaf. I know that it shouldbe done by spring specialists with their specialequipment, ovens, etc., but, as a motor mechanic,

know it is possible to do so in an emergency by

heating and using a piece of wood rubbed on theheated leaf. It is this method I desire to be sureof, and any advice ytiu could give me would beappreciated.-D. C. Brookes (Wirral).THE old-fashioned hand -fitting method is to heat

the spring leaf sufficiently to bend it to correctshape or camber, then harden it in either water or oil,and afterwards reheat at a lower temperature. Then apiece of hard wood such as a hammer shaft is rubbedon the tempered leaf to' give a spark up to a smoke.

As you have not the facilities for tempering orregulating the various furnace temperatures, there islittle we can do to advise you. Experience as to whetherthe plate is correctly tempered can be your only guide.The risk, however, of too soft or too hard plates beingbuilt into a spring by the old-fashioned methodsuggested is great, in view of the fact that the steelgenerally used in these days for motor -car spring platesis silico-manganese.

For your information, the heat -treatment for silico-manganese spring steel is heat slowly to a brightcherry red or just to a scaly heat (843 deg. C.), and hardenin warm water when the heat has gone down to a chcrryfull red (746 deg. C.). Do not let the plate remain station-ary in the water, but move it freely about until all theheat has gone. Temper in a slow fire until a piece.ofhard wood, when rubbed on the plate, will just catchfire, or when the plate can be seen to be a dull redheat when held in a dark place (50o deg. C.).

Battery ChargingT WISH to construct a charging board for 12- and-1- 6 -volt batteries, and intend to fix up a cargenerator driven by a h.p. motor. I should bemuch obliged if you would give me a diagram ofthe best method of wiring a board for 12.. and6 -volt batteries.-Thos. Hunt (Rowlands Gill).A CAR generator is self-regulating only when used

with the standard number of batteries and standardcharging rate for which it was designed, and you mayfind your proposal to use it for charging batteries of

Circuit diagram of a battery charger.

either 6 or 12 volts, and of various sizes, somewhattroublesome to accomplish. Your best arrangementwill be couple it to a .1 h.p. driving motor, with a variableresistance in the field circuit regulating the latter byhand until the charging rate is suited to the size of thebattery on charge. If more,,than one battery is oncharge at a time connect them in series, with the totalvoltage not exceeding 12 volts, and regulate the currentto suit the full charging rate of the smallest cell in theseries. Parallel charging is not recommended unlessyou have a separate variable resistance and ammeterin each branch to check up the charging rate. Theaccompanying diagram illustrates the sirnp:est connec-tion.

Depositing Carbon on Refractory SurfaceCOULD you tell me how I can deposit a thin

layer of carbon on a refractory surface, say,fireclay ? I only want it a few ten -thousandthsof an inch thick. How can I get on top of this athin layer of magnesium oxide of similar thick-ness ?-H. Brown (Thetford).VOU cannot satisfactorily deposit a thin layer of car -I. bon on a rough surface by chemical means alone,and, for this reason, you will have to employ somephysical method of btaining this end. The best waywill be for you to experiment by passing the fireclaysurface at a known rate through a smoky gas flame or

213

through the flame of burning turpentine. By dintof careful experiment you will be able to get reproducibleresults by this simple method, since by passing an articlequickly through a smoky flame an exceedingly thin filmof carbon can be deposited upon it.

The same method applies, also, in the case of thedeposition of a thin film of magnesium oxide. In thisinstance, the article is passed above burning magnesiumribbon or wire.

These methods are simple and fairly efficient andthey do not call for the use of expensive apparatus.Chemical methods in the instances you name areunavailable.

Boiling Points and PressuresTHE coupon enclosed is from the last issue I

was able to procure, having just completed12 months' service in the Orkney Islands.

Will you please answer the following queries :t. At what temperature Fahr. does water boil

when it is under the following pressures :A. 650 lb. per square inch.B. 750 lb. per square inch.C. 850 lb. per square inch.2. The amount of water to be evaporated to

raise a pressure of 25o lb. per square inch in a -cylinder, the dimensions of which are glin. by 51in.By that I mean that when a 250 lb. pressure hasbeen reached, all the water has been evaporated.-F. B. Almond (Hatfield).PURE water boils at the following approximate

temperatures under the pressures named :65c: lb. per square inch -248 deg. C.750 lb. per square inch -27o deg. C.850 lb. per square inch -285 deg. C.Above a temperature of about 360 deg. C. water re-

fuses to remain liquid, no matter what the pressuremay be. This is the " critical temperature " of water.Roughly sneaking, water advances to deg. in boiling pointfor every five atmospheres increase in pressure abovemedium pressures.

2. Your problem is not solvable with any precisionfor the reason that you do not state the temperatureat which the evaporated water vapour is to be maintained.Assuming, however, that the water vapour (steam) ismaintained around too deg. C., you would require about.3t c.c.s. water (or a little over an ounce) to attain thepressure you prescribe.

Locating Nails in TimberT SHALL be grateful for any information you can-1- give on the following matter :

Owing to the extreme shortage of timber,second-hand and reclaimed material has to beincreasingly used for munition cases and suchlikework. As you can imagine, although every effortis made to remove all nails, we are constantlyencountering large pieces of nail buried in thetimber, and these are not discovered until theyhave ruined the teeth of saws or the knives ofplaning machines.

I was wondering, therefore, if it would bepossible to rig up any form of nail detector, thatcould be placed on a suitable table over whichsuspected timber could be passed, and whichwould indicate by light or sound, etc., the presenceof buried nails. Incidentally, the size of the timberinvolved would vary up to about 6in. by Sin. maxi-mum cross section. I thought it might be possibleto rig up something on the lines of the " growler"used to detect faults in armatures.-W. V. Cox(Bristol). tr HE location of nails or iron spikes buried in old1. timber is always a problem. If the timber does

not exceed 3in, in thickness it may be assumed that theburied nail cannot be more than s _in. from one or otherof its surfaces, in which case it should be possibleto detect its presence before reaching the saw by passingthe timber as closely as possible underneath a veryfreely pivoted long magnetic needle, keeping a closewatch to see if any deflection of the needle takes placeas the timber is fed up to the saw. The pivot of thecompass needle should be slightly to one side of thetimber and not directly over it. No other iron mustbe in the vicinity or it will mask the effects. The useof a " growler " as used for detecting faults in electricalwindings would hardly be effectiVe, and the airgapbetween its "poles would be excessive and the resultstoo weak in consequence. The use of X-rays wouldsolve the problem effectively, but the preliminary

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214 NEWNES PRACTICAL MECHANICS

expense of the necessary outfit would be prohibitive,and in any case it is hardly. a workshop appliance. Thedeflection test with a sensitive magnetic needle is simpleand cheap, and it would be a simple matter to passthe timber along under it previous to placing it on thesatvbench. If a secondhand " mirror " galvanometercould be obtained, this would increase the sensitivityof the test.

Doubling Speed of MotorT WOULD be very grateful if you would give meA some simple instructions for doubling thespeed of a motor, which I possess. This is anAmerican (Century Motor Co.), 22ov. A.C. type S.P.(tingle phase, I believe), so cycles, 1.6 amps.,

h.p., 1,440 r.p.m. I have been told that if Ihalve the number of poles, I can obtain double thespeed, but on taking out the rotor, I failed to findany simple way of doing this without precise in-structions, as the fields appear to be sealed into thebody with bitumen. I need the motor for buffingup small objects, so if the h.p. happens to bedecreased slightly through alterations, this doesnot matter much, so long as I obtain about3,000 r.p.m.-J. M. Fisher (Finchley).'PHIS motor is apparently of the split -phase squirrel

cage type of single-phase motor, having a 4 -polestator winding and a 4 -pole starting winding inter-mediate between the main coils. It is possible thatthere may also be a circular coil of resistance wireconnected in series- with the starting winding andsecured to the stator coils. The possible methods opento you are as follow.

You might mount your motor on the floor and driveby means of a belt to the buffing head, the diameter ofthe motor pulley being twice as large as the buff pulleyto give you about 3,000 r.p.m. at the buff withoutalteration of the windings.

If you are able to check the ends of each of the mainwindings and the ends of the starting windings, youmight change over the ends of the coils as at a, b, c andd on the main stator windings. You might also dis-connect the ends of the two starting coils E and F,leaving these open circuited, and reverse the endsg and h of the starting coil K. Any resistance coil youmay find in the starting coil circuit should be left incircuit and an external resistance, such as a lamp,connected also in circuit. Alternatively, you might com-plete the starting circuit by a tumbler switch externalto the motor, as well as a lamp. The switch shouldthen be closed only during starting and afterwardsswitched off to break the starting coil circuit.

The only other method would be to rewind themotor, giving this two main stator poles of oppositepolarity, with intermediate poles of high resistancewindings as at present. In this event make quite surethat the type of wire used in the starting windingis the same as at present and that you understandthe arrangement of these windings. In certain machinesof this type the required resistance is obtained for thestarting winding by winding this with resistance wireor by reversing the direction in which the coils arewound partway through each coil.,

Step-down TransformerI HAVE built a rotary converter as follows :

I fitted a pair of slip rings to the armatureshaft of a /a h.p. compound wound D.C. motor,running at 5,500 r.p.m. and connected the sliprings to two opposite segments of the commutator.The input voltage is 230 D.C. and the outputvoltage with no load is 165 A.C. 25 cycles, and witha 75 -watt lamp across the output terminals theoutput voltage is xso A.C.

I want to step-down the output voltage to 8volts A.C. with as great a wattage as the converterwill give (I hope to use anything between 2 amps.'and S amps. if possible) and would like the par-ticulars of a suitable transformer. If you cangive me the windings and type of stampingsrequired I shall be very grateful.-James Robert-son (Perth).

Robert -

IF you can obtain sufficient current from the output1 side of your D.C. to A.C. rotary transformer tolight a 75 -watt lamp at 150 volts, there should be nodifficulty in operating a step-down transformer withan output capacity.of 8 volts 9 amperes. Owing to thelow, frequency of 25 cycles, however, the tore of thetransformer will be as large as one normally employedfor double the output on 5o cycles. Build the core ofstalloy strips s iin. wide of No. 26 gauge, to an overalldimension of 6in. by 4Iin. by r$in, deep, which leavesa winding space internally of 3in. by '}in. For a150 -volt 25 -cycle input wind the primary with 1,050turns of No. 24 S.W.G. d.c.c. copper, and the secondarywith 56 turns of No. 13 S.W.G. d.c.c. copper. Youmay be able to obtain the stampings from J. Sankey,and Spns, Ltd., Albert Street Works, Bilston, and thewire from Ward and Goldstone, Ltd., FrederickStreet, Pendleton, Manchester, provided you canfurnish an authorisation to purchase on Form " M "from the Board of Trade.

Smoke BombsT HAVE been asked if I can make up some formA of smoke bomb which can be either thrownby hand or rifle, for the use of the Home Guardin exercise. I would be obliged if you could supplyme with a formula for such, with the means. ofIgniting it, and any other helpful suggestionwould be greatly appreciated.-W. Miller (Glas-gow).YOUR best plan is to make use of a " zinc " smoke

which is fairly slow burning and which gives.a dense white, non-poisonous smoke.

A suitable formula for a smoke -producing materialof this nature is the following '

Zinc dust .. .. 25 per cent.Carbon tetrachloride .. 50.Zinc oxide .. .. 20Kieselguhr .. .. 5 , 1 .

The above mixture is ignited with a charge of iron dustand potassium permanganate, or, alternatively, by anyphotographic flashlight powder.

A somewhat superior zinc smoke is obtained accord-ing to the following formula :

Zinc dust .. .. 28 per cent.Zinc oxide .. .. 5oHexachlorethane .. 50

This is ignited by means of the following mixture :Antimony powder .. 76 per cent.Zinc dust .. .. itPotassium perchlorate It

Alternatively, you may employ the following smokecomposition which gives a brown smoke :

Saltpeur.. ..

tre -4512

per cent. (by weight)p hSul , .

Pitch 30 ,. pBorax .. 9Glue powder ..

This is ignited by means of a flash powder com-position, say a mixture of magnesium powder andpotassium chlorate or perchlorate.

In making up any of these chemical smoke mixtures,pack the composition in a tin can, and have a centralcore of the igniting mixture about three-quarters way

Resistance Resistance

Steirtntg.,,,fWinding Mate Winctinsi

Arrangement of windings for a split -phase motor.

up the can. This central core is connected to the sur-face of the mixture by means of a trail of ignition powder,with or without a length of magnesium ribbon.

We fear that it will be difficult for you to obtain mostof the materials above -mentioned at the present time.The best place to make inquiry for them will be atyour local chemical wholesaler, as, for example, Messrs.Griffin and Tatlock, of Glasgow.

Plumbago Crucibles : ContaminationCAN you give me any information on the follow-

ing queries :1. Where can I obtain a small plumbago crucible

to hold about two pounds of metal ?2. Does contamination take place if different

metals are melted in the same crucible ? Themetals I desire to melt are copper, brass, iron andaluminium. ,

3. Is any kind of flux required when meltingthe above metals for casting purposes ?-G. L.Fox (Nottingham).YOU can obtain these crucibles from J. Preston,

Ltd., 208, West Street, Sheffield, a.2. There is a grave risk of contamination if different

metals are melted in the same crucible.3. A flux of the charcoal type is required with copper,

brass and aluminium. Generally, no flux is neededwith iron.

Reclaiming Used Oils'T`HERE is a plant marketed for the reclaiming

(or cleaning) of used and dirty engine oil.Can you tell me the method of cleaning, and

also is it possible to make my own small plant ?-D. Anyon (Seafield).SUITABLE plants for the reclaiming of waste 'oils

are manufactured by Metafiltration Company,Ltd., 4, Belgrave Road, Hounslow, Middlesex, thiscompany specialising in this type of work. We would,therefore, "advise yclu to get in touch with them, statingthe type and quantity of oil which you wish toreclaim.

We are inclined to doubt whether it would be feasiblefor you to construct a really satisfactory reclaiming plant.You might, however, filter the oil under pressurethrough a column of animal charcoal mixed with fuller'searth or ltieselguhr, but this would necessitate yourusing compressed air. We think, therefore, that beforeyou proceed along any such lines, you would be betteradvised to approach the above -mentioned company onyour problems. Streamline Filters, Ltd., Ingate Place,London, S.W.8, is another company which makessimilar -filters.

Faulty Aneroid BarometerT HAVE an aneroid -barometer which is notA functioning properly, possibly due to thediaphragm, or bellows leaking.

Can you please tell me how to test for air leaks,

March, 1943and the best way to exhaust the air when re -soldering ?-F. G. Weir '(Rainham).UNLESS your aneroid barometer has been mechani-

cally rough -handled, we do not see why thediaphragm or bellows should give rise to leakage.However, you can quickly assure yourself on this pointby carefully dissembling the bellows and by heating itcautiously in front of a fire. In this heated condition,the part is then dropped quickly into a vessel of coldwater and held below the water surface. If leakage ispresent, water will obtain access to the bellows, and itwill make its presence known on shaking the bellows.

The only way to exhaust the bellows when molderingis to connect the bellows to an efficient vacuum pump,and then to " draw out " quickly she tiny air exit tubein a hot flame. It will take considerable practice foryou to do this, and we think the job would best bedone by a good optician and instrument -maker.

It is more probable, however, that the bellows ofyour barometer does not leak, and if you examine theinstrument carefully you may be able to find traces ofdirt or grease which may be causing the parts of thebarometer to stick.

Insulator for Magnetism !T WOULD be pleased if you could give me the

name of any material that is resistant to pas-sing magnetic rays, or a material that is a bafflefor magnetic rays.-W. R. Cleaver (Abergele).

WE do not know of any material yetproduced which can be considered

an insulator for magnetism. Air offers ahigh resistance to the passage of magneticlines of force, about 13,00o times ashigh as iron, so that the best way ofscreening a piece of apparatus isobviously to keep it well away fromthe magnetic field. Another method ofprotecting apparatus situated in amagnetic field from the effects of thatfield is to direct the field away fromthe apparatus by providing an alternatepath of low reluctance. This may bedone by fitting a piece of iron, of aslarge a cross section as possible, on thefield side of the apparatus and in adirection parallel to a line joining thepoles. If the magnetic field is varying,as may be set up by an alternatingcurrent, the iron should, preferably,be constructed of thin laminations whichare lightly insulated from each other.

Emulsifying Wax : Cellulose AcetateT WISH to make some emulsifying wax and shallA be glad if you will help me regarding thefollowing points : (a) Could you give me a suitableformula, the product to emulsify several timesits own weight of 1[120-ra little oil? (z) Howarc sodium carbonate pea crystals made ?(3) Can cellulose acetate be made with aceticacid, or must the anhydride be used ? (4) Howmuch of the acids nitric (HNO3) and HsSOa andH2O are used, and how long is the reaction, andat what temperature to make collodion ?-C. A.Godden (Twickenham).YOU can make an emulsifying material by mixing

about 5 per cent. of ammonia with turkey red oil, 'but you would be better advised to purchase a quantityof " Abracol " emulsifier (price about 2s. lb). fromMessrs. A. Boake, Roberts and Co., Ltd., " Ellerslie "Buckhurst Hill, Essex. This material is a waxlikepaste, and is excellent for the emulsifying purposeswhich you name.

(2) Sodium carbonate " pea " crystals are madecommercially by recrystallising the " technical " orimpure grade of sodium carbonate from hot water.The solution is made up to a predetermined strengthand is cooled down at a definite rate. The controlledcrystallisation of the solution results in these smallpea -like crystals. They are separate from the excesssolution and are usually dried in a " whizzer " or acentrifuge. For special purposes, the crystals aresometimes passed through a screen or sieve in orderto ensure them all being of the same approximate size.

(3) You cannot make the cellulose acetate whichyou require with acetic acid alone, no matter howstrong the acid may be. Cellulose (hexa) acetate ismade by heating pure cotton wool or cellulose withacetic anhydride for five hours at a temperature of18o deg. C. under a reflux condenser. A white flocculentmass results. This is cellulose acetate. It must, ofcourse, be washed very thoroughly in clean water anddried slowly. Most text -books on organic chemistrydescribe the process in some detail.

(4) Collodion is a solution of nitro -cotton in amixture of alcohol and ether. The proportions of thesetwo solvents in the mixture vary according to thepurpose for which the collodion is required. A littlecastor oil is sometimes dissolved in the mixed solventsin order to increase the flexibility. of the cellulose film.

To make the necessary nitro -cotton, ordinarycotton wool is soaked for four hours at ordinary roomtemperature in a mixture of three parts of concentratedsulphuric acid and one part of concentrated nitric acid.The resulting white mass is .then most thoroughlywashed in plenty of warm water in order to free it fromall traces of acid.

PRACTICAL MECHANICSHANDBOOK

12/6, or hr post 131 -Obtainable from all booksellers or by post frontGEO. NEWNES LTD. (Book Dept,). Tower House,

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WORKSHOP PRACTICEELECTRICAL SERIES, gDRAUGHTS NA A N SHIP aENGINEERING MATHEMATICS E._

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BRICK BY BRICK-Brick by brick, in this interesting model bungalow, PyrumaPutty Cement continues to build its reputation by addingnew fields-new techniques-new possibilities to themodelling world. This time it is in a model in which everyseparate brick, every separate tile, chimney pots and" concrete " surround, crazy paving and flower beds aremade in plastic Pyruma, baked to stone -hardness, colouredin natural colours, fixed in position with Tiluma jointingcement. The bricks were moulded in the simple multiplemould shown in front of the model, and thetiles in a mould equally simple to make.You must get to know Pyruma-it willbe of immense help in any modelling inwhich you are interested.

Above is shown construction of roof and also interior of themodel bungalow with cut away sections left to indicate wood-work. All jointing of bricks and tiles was done with Tiluma.

An illustratedInstruction Sheet onmodelling in Pyrumaand,Tiluma is obtainable on applicationto the manufacturers at the addressbelow. Pyruma Putty Cement and Tiluma are stockedby most Ironmongers and Hardwaremen, Stores,Hobbies Shops and by many Art material Dealers.

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216 NEWNES PRACTICAL MECHANICS ' March,. 1943

GALPINS-ELECTRICAL STORES

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ELECTRIC LIGHT CHECK METERS,well-known makers, first-class condition,electrically guaranteed, for A.C. mains200/250 volts 50 cy. 1 phase 5 amp. load,10/- each ; 10 amp, load, 12/6, carriage 1/-.AUTO TRANSFORMER, 1,000 watts,tapped 0-110-200-220-240 volts, for stepup or step down. Prire 85/., carriage paid.LOUD RINGING BELLS, working on110 v. D.C., 81n. diameter gong (hellmetal)plated, waterproof, new, 32/6, carriage paid.1 K.W. TRANSFORMER, input 100 voltsat 1,00 cycles, single phase, output 10,500volts. centre tapped to earth. Price14/10/-, carriage forward.

HEAVY DUTY CABLE, V.I.R., andbraided, in first-class condition, size 37/13,lengths 30 to 40 yards. Price by the length,5J- pet yard, carriage forward, or 7/- peryard for short lengths, carriage paid.200 AMP. SWITCH FUSE, three-way,Ironclad, unused, 400 volt, size overall30in. x 12in. x 12in., maker E. N: Bray,Ltd. Price Se, carriage forward.1 K.W. ELECTRIC FIRE Element, size16in. ic Ifin. x lin., for 220 v. mainsA.C. or D.C., as new, 6/- each, post free.POWER PACKS for smoothing, etc.,consisting of two 300 ohm chokes andtwo 2 med. condensers. Price 3/6, postftee.

ROTARY CONVERTER, D.C. to D.C.Input 12 v. ; output, 1,100 v. at 30 ra/a.Ex R.A.F., condition new. Pride 50/-,carriage paid.HEAVY DUTY KNIFE SWITCHES, D.P.,RT., quick break, 100 amp., in first-classcondition. Price 20/-, carriage paid.MEGGAR, by " Evershed Vignoles,"3,000 ohms to 5 megohms, 150 volts, size

x 7 x 12in., weight 201b., in perfectcondition. Price 1110, carriage paid.X-RAY TRANSFORMER, in oil -filled tank,medium size, input 220 volts, 50 cycle,1 ph. output 45,000 volts at 2 kW.,intermittent rating. in perfect order..Price 420, carriage paid.ROTARY CONVERTER, D.C. to D.C.input 45 volts; output 2,500 volts at1 k\V.. condition as new. Price to,carriage paid.

WATT WIRE END Resistances, new andunused, assorted sizes (our assortment),5/6 per, doz., post free.EPOCH SUPER CINEMA Speaker, 20watt, 15in. cone, 15 ohm speech coil,0 -volt field (no energising), in first-classcondition, weight 051bs. Price 117/10/-,carriage paid.ROTARY CONVERTERS, D.C. to D.C.,permanent magnet fields, small size,windings not guaranteed, ball bearing,contained in cast alli box, size 12in. x 4in.x 4in. Price 151-, carriage paid.AIR PRESSURE GAUGE, 9in. dia., ingunmetal, reading 0-4,000 lbs. per squareinch, condition as new. Price 50/-, carriagepaid.SOLID BRASS LAMPS (wing type), one -hole mounting, fitted double contact smallB.C. holder and 12 -volt 16 watt bulb.3/6 each, post free, or 30/- per doz.,carriage paid.2 M.F. CONDENSERS, 250 volt workingT.C.C. type, 1 doz. lots only. Price 15/ -per doz. post free.STALLOY TRANSFORMER SHEET, sizes,length approx. 10in. 3 widths 2in., 3in.,4in., gauge 20 S.W.G., quantity 1 cwt.Price, the lot, £3, carriage paid.50 DUD MOVING -COIL METERS, size2in. and 211in. dia., not repairable, thesemeters are offered only for the value of themagnets and bearings, all modern, allfamous makes, in cases as made. Price67/10/-, carriage paid.DYNAMO, output 20 volts, 15 amps.,shunt wound, slow speed, ball bearing,condition as new. Price 63/10/-, carriagepaid.TWO -GANG Variable condensers, smallsize, capacity .0005. Price 3/-, post free.SMALL ,TRANSFORMERS for rewindingonly, windings not guaranteed, core sizesuitable for 200 watts auto. Price 4/-,post free.

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Price 6f_ per lb. nett carr. paid.HOYT METAL CO. or GT. BRITAIN, Dept. Pm, DEODAR RD. PUTNEY,

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THE MECHANICALWORKING OF STEEL

By Edwin Gregory, Ph.D., M.Sc.(Lond.), etc., and Eric N.Simons. As a first introduction to what is fast becoming a subjectof great importance in modern industry, this book will proveuseful to engineering and metallurgical students to whom aknowledge of modern processes is important ; to thoseresponsible for those processes ; and to designers who shouldbe familiar not only with the elastic properties of materials,but of how advantage can best be taken of these to ensureresistance to strain. The explanations are suitable both for thelayman and the practising engineer.

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PELMAN ISMfor

Courage and Clear -Thinking

The Grasshopper Mind

YOUknow the man with a

" Grasshopper Mind " alwell as you know yourself. Hismind nibbles at everything andmasters nothing.

At home in the evening he tunesin the wireless-iets tired of it-then glances through a magaiine-can't get interested. Finally,unable to concentrate on anything,he either goes to the pictures orfalls asleep in his chair. At theoffice he alwalis takes up the easiestthing first, puss it down when itgets hard, and starts somethingelse. Jumps front one thing toanother all the time.

There are thousands of thesepeople with " Grasshopper Minds"in the world. In fact, they are thevery people who do the world'smost tiresome tasks-and get buta pittance for their work. Theydo the world's clerical work, andthe routine drudgery. Day afterday, year after year-eridlessly-they hang on to the jobs that aresmallest -salaried, longest-houred,least interesting, and poorest-futured !What is Holding You Back?

If you have a " GrasshopperMind " you know that this is true.Even the blazing sun 'can't burna hole in a piece of tissue paperunless its rays are focused and con-centrated on one spot ! A mindthat balks at sticking to one thingfor more than a few minutessurely cannot be depended %winto get you anywhere in youryears of life!

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Here is the answer. Take upPelmanism now !- A course ofPelmanism brings out -the mind'slatent powers and develops themto the highest point of efficiencyIt banishes such Weaknesses azdefects as Mind Wandering, Iittlr,feriority, and Indecision, and intheir place develoPs strong, posi-tive, vital qualities such as Opti-mism, Concentration, and Reli-ability, all qualities of the utmostvalue in any walk of life.

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March, 1943 THE CYCLIST 41

ti

VOL. XI

THE I cl

,-.4" -Editor : F. J. CAMM

MARCH, 1943 No. 253

All letters should be addressed tothe Editor, "THE CYCLIST,"George Newnes, Ltd., Tower House,Southampton Street,Strand, Londoft,

W.C.2.Phone : Temple Bar 4363

Telegrams : Newnes, Rand, London

Comments of the Month

Vehicle and Street Lightingri-1HE important topic of debate at the

meeting of the Roadfarers' Club heldat the Clarendon Restaurant on

Saturday; February 6th, was Vehicle and-Street Lighting. The meeting was wellattended and was preceded by a lunch.Mr. C. G. Grey presided over this meetingof the Roadfarers' Parliament and contri-buted to the debate. In opening it he saidthat the first Act which made provisions forthe lighting of road vehicles was the LOco-motive Act of 1898. This, however, merelyspecified that vehicles should carry a light-any sort of a light, fixed anywhere. Thislaw failed to prevent accidents on the highway.The Lights on Vehicles Act of 1907 was thefirst Act which legislated solely for obligatorylights on horse-drawn vehicles. It is a farcry from red flag days to red rear lights,and much heat has been generated in thecontroversies relating to lights. What arethe minimum requirements ? In the firstplace the driver of a vehicle needs 'to fit alamp which will not only illuminate hispresence on the road, but will enable him toproceed with safety during the hours ofdarkness, and illuminate the road for asufficient, distance ahead to enable him toobserve obstructions, pedestrians, cattle, orother vehicles and to be able to stop withinthe limit of the braking capacity of hisvehicle. Paradoxically enough when rearlights became compulsory on vehicles theAct only applied to motor -cars, and not to theslower moving vehicles. On the other hand,the driver of a vehicle of any class, whethermotor -car or a cycle, is entitled to rely uponthe common law that the onus of responsi-bility rests upon the driver of the overtakingvehicle. Thus it can fairly be argued thatrear lights are really unnecessary. Youwill remember the old couplet

He was right, dead right, as he sped along,But he's just as dead as if he'd been dead -

wrong.The lighting of streets and vehicles, there-

fore, must effect a compromise withoutimposing any unfair burden on any particularsection of road user. Anything which movesalong the road can be regarded as a vehicle.It may be logically argued that if rear lightson vehicles are necessary at all pedestriansand cattle should carry them !

During this war when for reasons of nationalsecurity the lighting of vehicles has beenrestricted, and the number of vehicles on theroad is reduced to one -tenth, accidents atnight have increased. They have not beenreduced by the slight concession allowingmotorists to use two dimmed headlightsinstead of one. The compulsory dimmingof headlights during the war has' not helped.Before the war, motorists sometimes usedheadlights which were far MO powerful ; somehad become selfish, and dazzle was thecommon excuse for head-on collisions at

night. Motorists, of course, are not com-pelled by law to have headlights ; the lawmerely specifies two white lights showingahead and fixed a certain distance fromthe ground, and also a certain' distance infrom the extreme edges of the vehicle.. Head-lights should be compulsory, and it shouldbe compulsory to use them:

After the war, dazzle should 'be made anoffence. We have seen that it is possibre toget rid of dazzle during the war, and whenthe street lights return it would seem thatthe present vehicle lighting will be adequate.

For one thing it keeps speed down, and thisshould, in peace -time at any rate, help, to re-duce accidents at night. The question of rearlights and headlights, and the position of thoselights on various vehicles, is a matter on whichvarious members of the club keenly debated.We can do much to solve the lighting problemby giving greater attention to street lighting.Powerful headlights are only used on roadswhich are poorly lighted. Greater use couldbe made of reflectors and street lamp standardscould conveniently be. lowered. A great dealof experiment has been conducted in this,direction, and especially with sodium andphosphorescent lighting. Coupled with itall is the question of the colour of the roads.By general consent a whitish surface is best.We must learn to light the way of the road-farer during a fog. After all these years isit not pathetic that road transport should bebrought to a standstill and roadfarers be-nighted because we have not evolved a fog -lighting system ?

In towns and cities should we permitflashing signs advertising various com-modities, which distract the driver of vehiclesand cancel out the effect of his lights ?Piccadilly Circus and Oxford Street inpeace-time.are good examples. .

The red light should only be used toindicate danger. If that is not possible thered light should only be used on the nearsideof the road to indicate an obstruction. Thedrivers of vehicles naturally tend to keep tothe right of a red light, and to the left of awhite light. Yet local authorities use redand white lights indiscriminately. Suchmisuse has caused many accidents.

Illuminated signalling devices as fitted tocars could be standardised and their use. madelegal. As it is the law only recognises the handsignal. A summary of this debate is to bereceived by Lord Leathers, the Minister ofTransport.

Lt. -Col. Charles Jarrott gave some interest-,ing views on the early days of cycling andmotoring, and dealt with the tests conductedat Blackheath by himself and Col. Holdenduring the last war on the colours of lights.He thought that pedestrians should wearwhite arm -bands. Dudley Noble dealt withContinental lighting, and spoke with favourupon the lighting of the Antwerp -Brussels

By F. J.

roads which are illuminated by sodium andmercury vapour lamps. The present war hasshown the value of searchlights, and hethought that these could be used in countrydistricts. Light towers which floodlit par-ticular districts could also be employed.

Capt. Day thought that two headlampswere unnecessary. He had invented a systemof lighting, making use of one headlamp, whichhad satisfactorily passed all tests, and did notdazzle. Unfortunately the war prevented itsadoption.

Mr. H. Boon made some most .interestingcomments on dazzle, and methods of avoidingit, whilst Mr. Bowman asked why lightswere always white, when yellow lights hadyielded better results.

Mr. Richford thought that high lightstandards should be abolished, and that weshould use divided roads with central lighting.He also thought that there should be somesystem of road markings indicating turnings.Another speaker thought that signposts shouldbe illuminated.

Mr. C. G. Grey thought that orange lightsWere best, and that lights fixed lower down onthe vehicle, as recommended by one speaker,would still dazzle. Greater use could alsobe made of polarised glass in avoiding dazzle,

The meeting unanimously passed the fol-lowing resolution which has been forwardedto the Minister of Transport :

That this meeting of the Roadfarers' Club,representative of all types of road user, isunanimously of the opinion that adequate,lighting of all roads should be the responsibilityof a Government central authority, and notleft to local councils, in order to secure uni-formity of lighting over the whole country ;and that such a scheme would eliminate thedazzle problem and enable drivers of vehiclesto use the very minimum value of lighting.Two low -wattage lamps indicating the widthof the vehicle and showing forward are allthat is necessary.

Mr. R. Sparks asked what efforts the RoadResearch Laboratory at Harmondsworth aremaking in the direction of road lighting.There are Home Office regulations regardingfactory lighting-why not for roads ?

RecognitionTHE Roadfarers' Club has received a letter

from Lord Leathers, 'Minister of Trans-port, stating that he will be pleased to receivefrom them memoranda on the subjects onwhich they debate and any resolutions Whichthcy pass. New members include : Brig. -Gen.Critchley, Sir Albert Atkey, Urban Taylor,Will 'Hay, Lt. -Col. Mervyn O'Gorman, RexColey, H. Morgan, Rev. B. H. Davies(Ixion of The Motor Cycle.), and F. R. Hook.

The next meeting takes place on Friday,April 16th, when the subject will be " RoadAccidents." The hon. sec. is R. A. West,32, Elm Bank Gardens, Barnes, S.W.


THE CYCLIST

Aker Bridge, near Bangor, Carnarvonshire.

Tamworth CastleRECENT business took me to the old town

of TamWorth, in' Staffordshire, and Ttook the opportunity of looking over theCastle-an ancient place indeed, for it wasbuilt originally by Offa, King of Mercia. Ifound it full of interesting relics, and in oneof the many roonis there is a fine collection ofstuffed birds. It is a place with a greathistory, and occupies a fine, commandingposition looking over the wide river. In thetown I paused and gazed for a while onthe statue of Sir Robert Peel. A modern'policeman stood nearby, and I fell to wonder-ing whether he realised that be was knownas a " Bobby " just because of the famousman commemorated by the statue. " BobbyPeel " was the virtual founder of our policeforce, and the first men enrolled were soondubbed " Bobbies."

Inside the ancient castle I had visions ofwarriors looking through the slits in_ themighty stone walls-scanning the horizon forthe sight of a foe ; I thought of the daYS whenEngland was divided into kingdoms, andMercia was one of the proudest. Outside inthe street I was brought back to modernity-and boarded a bus with a modern, pretty,trouser -wearing conductress who exchangedjokes with an American soldier.

Pump StealingI AM told that in some areas there is a bad

epidemic of " pump stealing." Now itis a particularly shabby trick to steal a pumpfrom a bicycle-the sort of thing that " is notdone." The punishment for offenders whoare caught should be sharp. But the wisecyclist will take no risks, but see that he re-moves his pump before he parks his machine.Or-perhaps better still-lock it in some wayto his mount, so that it cannot be removed.

Old Books and PeriodicalsWE are asked to do many things these war

days-save coal, save money, switch offlights, dig our gardens more intensively, anddo without anything we do not really need.And we are asked to do something else-asked by no less a personage than the PrimeMinister himself. , Mr. Churchill' recentlyaddressed a very special appeal to cyclists,asking them to look out books and periodicalsfor the Forces. Could there be any finer bitof war -work we could do ? All over England,in lonely camps, in hutments, in billets,

there are lads who have insufficient readingmatter. And on our shelves, in our attics andlumber -rooms, there are books which weshall never read again ourselves, but whichwould give pleasure to many a lonely soldierlad. Hunt them out ! Do it now ! Those oldnovels, those old magazines will be a boon to&any men in His Majesty's Forces.

Magic in a Map !0 anyone who loves the countryside, and

touring or tramping, there is no moretreasured possession than a map. By thefireside recently, I pored aver anold ordnance map, and lived again some ofthe good rides, and walks, I had done in theEnglish shires. I browsed over Buckingharn-shire, and memories came crowding in ofgood rides through the Chilterns. I recalleda " high tea " I once had in a cottage nearWendover, and Wondered when I shouldsee such piles of bread-and-butter and cakesagain-Or such " lashings 4' of home-madejam ! I sauntered through Suffolk, and hadgood memories of Clare, and Long Melford,and the " Constable country " in the Stotirvalley. And I rode, in fancy, down Devon-shire lanes sweet with the scent of primroses.My eye roamed over Essex, and I loved againthose delightful place-names which aboundin this county so near toMother London. Away up-to Lancashire, which alsohas its pleasing place-naines-as witness" Chamock Richard." ButI finally came to the con-clusion that no county canboast sweeter village namesthan Cornwall-with " St.Just -in -Roseland " as per-haps the loveliest of themall. There's magic in amap;

London Memories

S0 M E little business1-1 reorganisation hasbrought me back to London-2-and after an exile ofthree years in the provincesI am finding new delightsin the " big village." Isthere anything in the worldso unique, so " belonging,"as the subtle smell of

March, 1943

CycloramaBy H. W. ELEY

a London street ?' I sniff the air as Idescend from the train at Euston-and thereit is-the indefinable, alluring smell ofLondon Town. True, it is a London whichbadly needs a coat of paint. It is a Londonwith ugly, unhappy gaps in the familiarstreets. But it is the only London withhistory in its stones, and with the oldirresistible call to all its children. I havepromised myself many treats-visits to someof the remaining City Churches ; visits tosome of the old taverns, where the shadesof Dr. Johnson and his cronies still hauntthe ancient rooms, and make the very tap-rooms places of history and legend andliterature.

Road CasualtiesTHE latest figures in connection with road

casualties make very disturbing reading.The black -out may have a lot to do with thestill alarming figures but, whatever the cause,all must deplore the sad toll of the road-and all must play their part in trying to bettera sorry situation. In the month of November,681 persons were killed on our roads, and12,480 were injured. Deaths in the black -outnumbered 342. Now, this figure appears tobe less than half the corresponding figurefor November, 1940, but it must be borne inmind that now we have far fewer vehicles onthe roads. The urgent need is for still greatercare ; for a greater realisation that lives areprecious.

Winter CompensationsAS I write, a rapid thaw follows a short,

sharp period of frost. There is amelancholy drip -drip from the trees, and thelawn on. which I look out is a thing of patches-green showing Zthrough the melting snow.A disconsolate blackbird hops under thelaurels, arid two sparrows fight for the crumbson the bird -table: It looks as if the afternoonwill be foggy. Altogether, a day for thefireside, a pipe, and a book. I stretch out myhand for my old tobacco jar, glance at thebook -case, and wonder whether GeorgeBorrow, or Mr. Pickwick will be the betterfireside companion. Borrow wins, so, withpipe going well, I settle down for the rollingroad, the windy heath, and all the winningways of the care -free Romany.

This handy little three-wheeler serves a useful purpose in London,transporting parcels of hospital essentials.



Cavendish, Suffolk. The interesting church dates- mainly from the late 15th century.

Around the WheelworldBy ICARUS

RelIPve It or Not !THE Cumber cycle shown in the illustra-

tion was the machine on which C. A,(Bath Road) Smith beat the Brighton coachrecord in 1890, his time being 6 hrs. 52 mins.to secs. This record was beaten by Edge by

min. in 1892, and C. A. recaptured it in1893, in the time of 6 hrs. 6 mins. You willobserve that the machine has large sectionpneumatic tyres and a nice bent frame, whichmust have warped and twisted and wasted aConsiderable amount of power. Notice alsothe elegant 'saddle' and the flat handlebars,which to -day are favoured by some riders.The Cumber cycle was famous in its day.They were made at All Saints' Road, West -bourne Park, London, W. I wonder howmany modern riders could push (that is theoperative word) that machine to Brighton in6 hrs. 6 mins. ?

Road Accidents in 1942THE road accident figures for December,

1942, were the highest for any month ofthe year, totalling 780 killed and 12,842injured. These figures compare with 1,024killed and 18,300 injured in December, 1941.

Since the war the December accident peakhas been more pronounced as a result- ofblack -out accidents ; and last Decembernearly three-quarters of the pedestrians killed,other than children, lost their lives during thehours of darkness. Fatalities to children,including cyclists, numbered 109, and, inaddition, 1,65o were injured.

The total number of lives lost on the roadsof Great Britain in 1942 was 6,926. Althoughthis shows a decrease of nearly one -quartercompared with 1941 (9,169), the improvementis not so great as might have been expected,having regard to the fewer vehicles on theroad. It should be remembered also that inthe early part of 1941 the danger of roadaccidents was increased by heavy enemy airraids, especially at night, and the consequenthurry to get home.

During the year 1,315 children were killed,as against 1,462 in the previous year. Apossible cause of the high proportion ofaccidents to children is that many parents arenow engaged in war work and find it impossibleto exercise the same supervision as they

would in normal times. In such cases theinstruction of children in the correct use of theroads is especially important. Arrangementsshould also be made, wherever possible, forchildren to be escorted by neighbours.

The following figures show the trend ofroad accidents during the war years :

Total all personskilled .. .

Total child pedes-trians ..

Total child pedalcyclists ..

1939 1940 1941 1942

8,272 8,609 9,169 6,926

850 972 1,231 1,112

184 205 231 203

Cycling Without LightsUNTIL the shortage of cycle -lamp batteries

is made good, it has been suggested tothe Home Secretary by the National Com-mittee on Cycling that the police shouldexercise a wise discretion in refraining fromprosecuting cyclists who ride without lights.

" We welcome," said Mr. H. R. Watling,chairman of the committee, recently, " theaction of those police authorities who, aftersatisfying themselves that there is a realshortage of batteries in their districts, havenot only refrained from institutingprosecutions but have been sufficientlybusiness -like and helpful to makerepresentations to the proper authori-ties.

" The shortage is not, in fact, thefault of thoseimmediatelyconcerned. Iam satisfiedthat the Boardof Trade aredoing theirbest in verydifficult cir-cumstan cesand so are thebattery manu-facturers. Asfor the cyclists,few of themwould riskriding withouta light unlesscompelled to

do so.- If they do not cycle they haveeither got to increase the existing congestionof other means of transport, where there isany, or they must just walk-and thus losevaluable working hours.

Neither of these alternatives is in thenational interest. Most cyclists are alreadytired enough with war work and their spare -time Civil Defence duties. In a single weekrecently 600 man hours were lost in a factorynear London because men and women werelate on account of the battery shortage. Allthings considered, the best solution while theshortage lasts is a recommendation from Mr.Herbert Morrison to the police, thousands ofwhom are themselves cyclists, to exercise awise discretion."

Since the issue of this announcementa statement has been issued in Parliament andI understand that reasonable supplies ofbatteries are now available.

Lunch Paper -24 Tons

THE paper in which Fort Dunlop workersbrought their lunch to the canteen last

year weighed more than 24 tons. It is asurprise in the total of 194 tons 7 cwts. and2 qrs. collected there for salvage during 1942.

Daily papers and weeklies contributed,along with office paper, more than 58 tons,and there were close upon 102 tons of card-board.

Apart from the waste paper actuallycollected, many more tons have been savedby straightening out old brown paper andusing it again for wrapping, by the return ofpacking to suppliers, and by using the plainside of used stationery.

A New National Body?DURING my social round of luncheom,

a few dinners, and week -end runs I havediscussion on the

present disputes between certain clubs andnational bodies. There can be no doubt thata strong movement is afoot to form a new one,which, say the critics, will be more in keepingwith modern times, and run by young andactive cyclists. One club of standing hasalready broken away from two national bodiesand joined another body recently formed.From the conversations I gather that thismovement is receiving considerable support.The main argument is that the N.C.U. hasno control over mass -start racing on theroads, and therefore their bans on particularriders who take part in mass -start racing onthe roads are illegal. If this movement growsit will weaken the existing national bodies.We must remember what happened with theold Road Racing Council, out of which grewthe Road Time Trals Council.

The Cumber cycle, on which C. A. (Bath Road) Smith heat the BrightonCoach record in 1890.


44 THE _CYCLIST March, 1943

WAYSIDE THOUGHTSBy F. J. URRY

Denham, Bucks. Aview of the picturesquevillage street. On theright is the old Black

Swan Inn.

Black -out MasksMANY have been the criticisms, and -much has

been written on the subject of the feeble illu-mination allowed to the cyclist under the black -out

4 regulations ; and I am bound to confess there isjustification for the complaints. Only those who arecompelled to ride after dark-or before the break ofday-can fully realise the discomfort of travel, andthese are the folk loud in their demands for bettertreatment, justifying their complaints by the fact thatmotorists are given a much better deal in this matterof. lighting. If anyone reading these notes disagreeswith my opinion on this matter, I can only recommendhim to make his own test anywhere, on any dark anddirty night, and I am certain the result will be, at thevery least, a sympathetic feeling for the night -ridingcyclist. Now, the Ministries of War Transport andHome Security recognised this fact nearly I2months ago, and set to work to remedy it so far as theywere able. They designed a funnel -shaped mask toreplace the present regulations, which was to projecta brighter beam. forward so that the user could moreeasily pick up the kerbs, and sight a pedestrian orobstruction in time to pull up without the risk ofcollision. Interested cyclists tested this new designat the invitation of the Ministries concerned, and

*seemed reasonably satisfied, and as I know many ofthe men who were present at that demonstration, Ihave no doubt the new design of mask in its originalform was an improvement on the old type. Well,something must have happened between the time ofthat demonstration and the issue of the blueprintsfor the manufacture of the new mask, some vitalalteration which has made the mask nothing betterthan a delusion and snare, for it is no good. Thatis a very definite criticism, but it is true, being basedon a series of trials with the new mask mounted side byside with the old one, and I say the old one wins handsdown every time. It is a pity after so much time wasted,but it is true, and there is little more to say on thematter except this.

The Real SolutionTHE old mask cost sixpence, Lucas' retail price, and

within its limits it was effective and cheap. Thenew mask is not effective in its presentdesign and wouldcost at least 2s. 3d. retail, a figure which at once damnsit in the eyes of millions of riders, so in a sense it is agood thing it will not be marketed, anyhow in its presentform. Now let me tell you this:When the black -outregulations for cycle head=lamps came into force I wasusing for my night journe.ys an old but very serviceableHolophote oil lamp burrung an inch wick and giving abeautiful golden glow, mainly because of its excellentreflector. I did not like to spoil that reflector becauseit would be' impossible to replace, the Holophotehaving gone out of production at least 25 years ag6;so I just blacked -out the top half of the lens and carriedon with a good mellow light that is never dazzling ;and up- to the moment I have not been 'challenged byauthority for this slight evasion of the war -timelighting -laws. Indeed, I think it would be difficult forthe police to question my lighting shortcomings, seeingthat at least half their own lamps do not abide by theregulations. That, however, is -beside the point, for Ishould' think, from my observations, half the night -riding cyclitis are also black -out transgressors, asindeed am I, when the old oil lamp is in, use. Takingthese things into account, I see no good reason why theblacking -out of the top half of the lens-a very simpleoperation-and leaving the plated reflector alone,should not meet the needs of the cyclist and the wishesof the Ministries concerned. We should then be granted

a "seeable " light at minimum cost and trouble, eas lychecked by the powers that be, and in my opiniongenerally satisfactory to all concerned. And this formof black -out could be put into operation at once. I makethe suggestion-again after experience-convinced itis the right solution, and even if it were adopted, we,using battery lamps, would have a less dazzling lightthan the dynamo user, and far Iess than the motorist.

It Is Worth ItTHE first month of the new year has flown, and in a

few weeks we shall be looking for the first signsof spring, the lighter skies and those streaks of windysunshine that stir the souls of men. It is true that wecannot get away from the war and all its implications,and the fact that we have to face a ghastly year ofmounting tragedy with set faces and, a grimmer deter-mination than ever; but thoSe of us who are still leftin civilian life and still possess the ability to ride abicycle are in a favoured position, and should be verythankful for the possession of our health and activityto do those things within our power to preserve it. Iknow I am, for never in my life have I been so thankfulfor the services my bicycles render me, and to manyof my young friends with a few days of leave. Everyweek during the winter I have snatched a few hours togo wandering, hours that have been a comfort and asolace, and sent me back to work with a greater lovefor the pastime of cycling than I thought I could still

'acquire after over so years of riding. There is a quiet glowof glory in these journeys that can never be captured ina mesh of words and broadcast to the million it is allso purely personal, depending on your loneliness oryour company, the mood of the moment, the friendsyou visit, the unrehearsed welcomes of the wayside, andmore than anything else that love of country inherentin most of us, but alas, only specialised in the too few.I sometimes wish I could telj people of all the thingsthat hold me to this cycling game, ,such trivial things,that. when I come to analyse them they are nothing butthe stuff- of dreams, yet their cumulative effect is abenison to the spirit and a halo to health. It isn't thedistance I ride-that is moderating with the years-itis thyouch of things seen ind heard and scented, theimpact of quick -changing loveliness, the pipes of Panfrom the throat of a thrush and the deep diapason of awinter dirge through the bare woodland aisles. Goout, I beg of you, whenever you can ; get fit for Easter-late in the calendar this year --and make the shortbreak a pman of praise for the freedom of the road, theonly free man now wandering on wheels to be found?hereon.

From a CentreWHEN this war began I got into trouble with the

younger generation for suggesting that before thestruggle was ended accommodation for shelter and foodwould become difficult ; and bicycles would be hard toget. There was nothing prophetic in that statement toanyone who lived through the last war, and I onlyissued it as a warning of what we should expect. As amatter of fact, we are, in the fourth year of the war,much better off as cyclists than was the case at thebeginning of 5918, for the touring cyclist can still findaccommodation in favourite areas, while the YouthHostels and the British Restaurants have been ofenormous aid to him. When and if I have a few daysto spare this year-and I am full of hope-I shallmake fora centre and gravitate from that harbourage.It is not the free-est form of touring, but it does giveyou the certainty of night accommodation, and leavesyou unworried to spend the long evenings on theroad with the knowledge that your bed is safe. It istrue, too, thatin many of these small places the foodProblems are not so pressing as in the larger centres,so that often enough, with a Thermos of coffee, you canfill your lunch bag with a mixed assortment of !theclinties from the corner shop, and he is a poor wandersr

who cannot persuade a cottager to provide tea, especiallyif you are prepared to supply the fragrant herb and thesugar, if any. This is the method I would recommendto the tourist, and a farmhouse is as good as-nay, betterthan-most harbours, for though the food there may beplain, it often tastes ambrosial to the townsman'spalate ; and the farm gets up early, which to me is arecommendation of considerable import. Don't giveup the chance of a tour for the sake of a little trouble,for this perfect expression of a holiday is worth theeffort to obtain it.-'

The' Old GameYOU may, of course, think the time of the year is

inopportune to talk of holidays, and so, perhaps,it would be in the usually accepted sense of the term,but since pleasure cycling to me is always a holiday,however brief, then cycling and holidays are almostsynonymous terms in my mind. That I presume is acondition that only grows as the habit of the gamebecomes part and parcel of one's life, when you havegiven yourself to it without knowing precisely when,or even possessing knowledge of the fact that it isso, until suddenly something happens and you aredivorced from your bicycle for several days, and wonderwhat on earth you would do if such a condition lastedfor the remainder of your existence. The fact is, Isuppose, few people give themselves wholly to cyclingin the sense that if all other leisure -time. employmentceased, they would not find themselves effete, or lackingthe wherewithal to taste the spice of life. like othergames, for they act as a background to the main pictureof my life, and by indulging in them I discover, oftenrather surprisingly, how little variety there is in the play-ing of them in comparison. Maybe it is as well that acycling scribe should be a cyclist, just that and littlemore, for if this lobe of the -pastime had not happenedto some of us, I feel that the merits, and especiallythe half -hidden merits, of silent wheel wandering .would never -have been told, feebly at we may interpretthem. As -it is ,you have to put up with this old bore,and make the best of him, if on occasion " he babbleso' green fields," and has only the limited power topresent in print all that he feels in mind. The in-escapable fact is that my years are running out, and withthat background of knowledge, the fragrance and beautyof these free hours I gather to myself along the roadbecome infinitely precious. That is what cycling doesfor you and to you if you are loyal to its call ; it becomesmellow and more splendid with the passing years, andinto it merges a measure of gratitude for your activityand that cheerfulness which is the savour of living.

For the _FutureSOMETIMES I wonder if all these random remarks

' I make on paper are read by the people to whomthey are supposed tobe addressed, and no sooner

'such a doubt enters my mind than I receive a batch- offriendly letters from folk of WAbse very existence Iwas previously ignorant. That is always a hearteningexperience, particularly when some chance remark hastouched a chord of memory in the heart of a lad faroverseas, waiting for the day of his return to put intooperation many of the things these notes try to suggest.Last Christmas I had dozens of letters fromunknown friends in which I was gladly made awarethat there are many riders after my own heart, and Igo on my way rejoicing because it is so. I sometimeswonder if these epistles, with the personal touch cutout of them, could be printed as a testimony to cycling-not the bicycle or the rider-but the sport andpastime as it is seen and felt by these exiles from theland of their love. Cycling, as such, has never hadenough publicity, probably never will have, owing tothe cause of competition which must perforce mentionnames of makers. It is one of the reasons why havealways advocated a poster campaign on behalf ofcycling-just cycling in all its phases, without themention of a name or the suggestion of advertisementvalue that could be linked to a name. Obviously thetrade would have to pay for such publicity, and up tothe moment they have not seen the force of this argu-ment, and why, I have never been able to understand.Perhaps, before the war, cycling was considered a joke,indtilged in only by the impecunious, and those whoseldom or never node believed. this to be true. Well,it isn't, and if ever the time existed to make cycling ahabit for all and a joy for the majority, it is now andduring the immediate future. Snobbery in the form ofcash consciousness will surely die by the progress ofsocial reform, and cycling will live on. Give it the goodwine of publicity.

N.C.U. News ItemsThird Party InsuranceTHE N.C.U. announces that by arrangement with

their underwriters N.C.U. Third Party Insur-ance now covers business riding, as well as riding toand from business and for pleasure purposes.

N.C.U. OverwhelmedALTHOUGH 1942 was a record for wartime member-

' ship, the first four weeks of 1943 have eveneclipsed that good going, and the staff at Union head-quarters are severely taxed to cope with the rush ofapplications that are coming in from all, classes ofmembership. Applicants are asked to exercise patience,as it is quite likely that replies to them are a weekbehind time. All are being dealt within, strict rotation.

The Union would like to call attention to the fact thata number of postal -orders are lying at the Union's officessent in by applicants for membership who have failedto put their name and address on their application formor letter,


March, 1943 THE CYCLIST '45

At-

1

My Pointof View

'1. '#4 Cr fir-4St Mary the Vixgirt. Adderbury(C)...)

Strin5th.

Bicycles for HireTHE advertisement of a Surrey hotel attracted my

attention recently. The closing words were :" Bicycles and pony -trap for hire."' Remarkable, isn'tii ? Probably, however, the younger generation ofcyclists are quite unaware that the hiring -out of bicycleswas once an important part of a cycle -trader's business.But to think of a hotel, in 1943, descending (I am surethat " descending " is the right word to use, thOugh tomy mind the movement is in the opposite direction 1)to the provision of bicycles for hire 1

Worthy of NoteFROM an article on "Re -grouping the Police ". in

The Times of January Mth : " When, after thewar; the Defence Regulation under which the Home

, Secretary has acted is withdrawn, amalgamation willlapse-unless Parliament by legislation authorises itscontinuance." Here is the answer to the ignoramuseswho say that cyclists will never escape from the ridicu-lous necessity of carrying rear lamps, and also to theirforebears, the wiseacres who insisted that the oldD.O.R.A. regulation to the same effect should havebeen continued after peace was re-established. "Theforegoing quotation is worthy of note-and of pare-phrase-,by the people who talk like parrots, or defectivegramophone records, repeating themselves ad nauseam.None of the existing temporary legislation can becontinued after the present emergency has passedexcept by constitutional action in the Houses of Parliament.And then, if the rights of cyclists are attacked, weshall fight. Make no mistake about that.

Mouth -organ CyclistsTNURING a conversation recently with a factory.1- operative who is also a club cyclist, he spoke withsome little acerbity concerning mouth -organ cyclists-those otherwise quite worthy young people who appearto think a trip into the country is incomplete unless theyare armed with the wherewithal for adding to the world'salready excessive clamour. The lad who was speakingto me put the thing this way : " I get all the noise Iwant here for eight or ten hours a day. When I go outcycling I want to travel in peace and quietness, so thatI can enjoy the silence of the countryside, and hearthe birds when they sing, and listen to the wind in thetrees. No mouth -organ cyclists for me ! " The com-plaint is not a new one. Mouth -organs are not every-body's cup of tea," which is something for which tobe profoundly thankful. Personally, if I never againheard one of these " musical " instruments, I wouldnot shed a solitary tear I

" Holidays at Home"THE suggestion of " holidays at home" has already

been put forward for wholesale alloption (it ispresumably hoped) in 1943, as in 1942. The questionis not one for general discussion in these columns, andwe must stick to that aspect which concerns us ascyclists. Let it just be remarked, howetmr, that theGreat Thinkers who would have the whole populaceconform to their plan of staying at home for theirholidays could do with one or two lessons in psychology,which would enable them to realise that public transportis not the only thing that matters-and that there is atremendous bulk of transport other than the public type.

Turning to the purely cycling point of view, twofacts at once emerge. (1) If it is necessary for us widelyto adopt the " holidays at home " idea, then, you andI can still have a jolly good time. On one of my vacationsa few years ago, it was desirable for me never to befar away from home, and so I went out immediatelyafter breakfast each morning and did a big ride, gettingback in time for supper. It is open to question whetherany other section of the community can extract so muchvalue out of " holidays 'at home." In fact, I am surethat they cannot. To my mind, there is nothing likegoing right away, but if this cannot be managed, thena daily ride of anything up to loo chiles constitutes avery good substitute.

EY WAYPAREI2

(2) But is it necessary for cycliststo follow the crowd-if the crowdtakes any notice of the " holidays athome," cry ? Most certainly not. Aswe do not normally use publictransport, thereis not the slightestreason in the world why our, holidaysShould be varied from our usualmethod. On the other hand, havingregard to the need for physical and

WIC mental reconditioning, so vital inthese times, there seems to me to beevery reason why cyclists should carry

on with their normal holidays, with the proviso that theyrefrain from seeking train aid. It is also worthy ofrecollection -that certain people in this country maketheir living out of catering for cyclists. Surely we canhelp them to keep the wolf from the door. We shallneed them after the war, and we ought to do somethingto keep them in business.

Incredible .-T HEARD the other day, at second-hand, of a lady whoA asserted that she had been fined for not dismountingfrom her bicycle at a " Halt " sign. Frankly, I don't

see how it can be true, and I refuse to believe the story.If it were a fact, however, it appears to me that a verygrave injustice has been done, and it is hard to believethat even present-day justices, thinking, through themedium of their learned clerk, could do such awrong. The intention of the " Halt " injunction isperfectly clear. So is its purpose. If you carry thisnew interpretation to its logical conclusion, thenit would be necessary for every passenger in everymotor vehicle to be disgorged on to the road at every" Halt " sign-which, as Euclid would have said, isabsurd. Nor would the purpose of the sign be renderedmore effective. On the other hand, great delays wouldbe caused while people were leaving and entering theirmotor -cars. No. It won't do. The word " Halt "means " Halt " and nothing mbre. But it does mean" Halt I "

Nonsense VerseT HAD occasion recently to criticise a poetic effort

on the part of one of our cycling " legislators,"who was intent on discouraging enthusiasm in cyclists,and I did so in very frank terms. The only sort ofenthusiasm which should be toned down is that whichexpresses itself in enormous mileages-cycling for thesake of cycling-and which inevitably burns itselfotit in a very short time. But this " poet " was anxiousto take the top layer_ off all enthusiasm, andhe did not seem to mind to what lengths he went toachieve his outrageous purpose. Thus in one non-sense verse you were warned against being rapturousover the surrounding scenes lest you skid on wet leaves.It may be unusual,' but in the course of a long cyclingcareer I hive never known of any skidding throughthis cause. (A professional writer' has -since come inon the same. wavelength, and-at the end of December !-has Spoken of the danger of wet leaves as a skid agent.Evidently' his calendar needs attention, becauseat that time of the year leaves and blackberries -viewith one another at the scarcity counter. They aresimply not there.) Returning to our nonsense poet,he also warned cyclists against the folly of giving alltheir attention to the woodlands and the hedgerowsin case they were floored by frozen ruts : also to bewareof enthusing over the sunset in case they should hit amotor bus. Stuff and nonsense-which a little practicalacquaintance with cycling would have avoided.

12'

Notes of a HighwaymanBy LEONARD ELLIS

ONE of the best-known touring spots in North Walesis, of course, Lake Bala, or Llyn Tegid, as they

'say in Welsh. It -is a beautiful sheet of water, perfectlynatural and probably the largest in Wales. It is aboutfive miles-long and nearly a mile across at its widestpart. It is interesting as the birthplace of the RiverDee, which flows away at the north-eastern end, wandersthrough the lovely Vale of Edeyrnion to Corwen andthence to Chester and the sea. It is a splendid centrefor touring, as many roads radiate from the little markettown of Bala situated at the northern or lower end.Three roads go northward and join the Holyhead road,or As, at various places, and another goes south-eastward to Llanfyllin over the celebrated Milltir Cerig,or Stony Mile. There is a road along each side of thelake so that it is possible to cycle all round it. Fromthe southern junction of these roads there is anotherthat goes southward to Dolgelley. There is anothercelebrated rough road leaving the Dolgelley road nearthe south end which -includes the Bwlch-y-Groes, orPass of the Cross, reaching a height of 1,79oft. at thesummit.

Further Touring- RoutesTHIS is a grand, wild road of very rough surface and

full of adventure. As we leave Bala going southwardwe follow a road cut in many places from the mountainside and hanging over precipices. Beyond the summitwe drop rapidly into the Valley of the Dovey by wayof Dinas Mawddwy, a charming spot on the Welshpool-Dolgelley road. Justbeyond the summitthere is another roughroad, scarcely morethan a track, that .toesoff to the east /andeventually brings usto the head of LakeVyrnwy, an artificialbut lovely lake, sup-plying Liverpool withwater. Bala town ispleasant enough tostay in but has littleof history or ofinterest. If there isno history, there isplenty of legend.surrounding the lake.A local superstitionsays that the oldtown lies some-where in the middleof the lake. It godon to prophesy thatthe lake has alreadyswallowed Bala andwill in the fullness oftime swallow alsoT.lanfor. a village

nearly two miles from the banks. The Old legend saysthat many years ago there lived a happy and contentedcommunity who drew their water from Gower's Well.

The Legend of the LakePHIS well had a spirit who was apt to get very angry if

the well were left uncovered at night. The villagersrealised the importance of keeping the spirit good-tempered and appointed a guardian, v,bbse sole dutyit was to cover the well every night as soon as thevillagers had retired. One night he failed in his duty,while joining in some celebratiehis. Too late thevillagers tried to cover the well, but it was hopeless.Water was pouring from it in a great flood and nothingcould stop it. The water rose and flooded the streets,entered the houses, woke the inhabitants and soonchaos reigned. They fled to escape the water, notforgetting to try to 'punish the guardian, but he alsohad fled, more in terror of the villagers than of the water.It was the water, however that punished him, as he wasswallowed up in the flood and was never seen again.In the morning the people shivering on the hillsides sawa vast lake where there used to be a village, and theydo say that on stormy days the waters seem to ooze upat the lower end of the lake as if the old well is stillgushing and as if the spirit is not yet appeased. Somefolk still believe that on a very clear and calm day, .when the surface of the lake is quite unruffled, 'thechimneys and roofs of the old village can still be seenat the bottom of the lake.

Bala : the birth of the Dee.


46 THE CYCLIST March, 1943

A HARD LIFE AND A LONG ONE

Britain's precious stocks of rubber are temporarily irreplaceable!Fewer cycle tyres are being made, and those you now have mustbe made to last as long as possible. Experience shows that tyresinflated hard; and kept hard, last longer-that's what we mean by"a hard life and a long one."

DUNLOP CYCLE TYRES'KEEP THEM LONGER

BY KEEPING THEM HARD2H/320

White Down Hill, Surrey's well-knowntest hill, must be negotiated with care-you need sound brakes and depend-able brake blocks. Ride with greaterassurance of safety by fitting Ferodo'All-weather ' brake blocks. They aresure -gripping in all weathers, noiselessand long lasting. On hills like this ...

if100110041



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Well Done, DulwichOF the 47 members of the Dulwich Paragon C.C. in

the Forces, 17 are serving overseas,

Loch Fyne Ferry StoppedTHE ferry across Loch -Fyne, between St, Catherine's

and Inveraray, has been stopped.

Travel PublicityHE colour films of the Scottish Y.H.A. have nowT been shown to audiences numbering aca,000 in all.

Track Dress PermittedSCOTLAND has decided to allow dark track dress

in time trials, as well as tights or shorts and blackjackets.

New Hostels GuidesTHE Scottish Y.H.A. is to publish new guides to

Loch Lomond and the Trossachs, and to theBorder Country, this year.

New Hostels for 1943MEW hostels Ire to be opened in 1943 by the Scottish

Y.H.A. at Cove, Kingussie, and Alltsaigh (LochNess).

No Standard handicapsAA SCHEME of standard handicapping, proposed

by the Mid -Scotland T.T.A., has been rejectedby the Scottish Amateur C.A.

War -time Championship for ScotlandAT its meeting recently, the Scottish Amateur C.A.

decided to hold a war -time emergency champion-ship over 25-50-aoc miles.

Award to C.T.C. MemberT EADING SEAMAN R. W. LEE, of the Cyclists'A-- Touring Club, Kidderminster Section, has beenawarded the D.S.M. He is a gunner in the MerchantNavy.

Appointed AuditorsGEORGE It. HERD, the timekeeper, and Harold

Brierclatfe, Glasgow cycling journalist, have beenappointed auditors to the Scottish Amateur C.A.

No More PublicityQCOTTISH time trialists have rejected a plea fromLl Dundee that more publicity should be allowed toannouncements of forthcoming open events.

'radesmen's Baskets AllowedALTHOUGH the Government has banned the.

making of some wicker baskets, baskets forlc; tradesmen's carrier cycles are not included in the order.

Advocates Motor RoadsQPEAKING ai a road safety exhibition in Glasgow,*.-7 'rom Johnston, Secretary of State for Scotland,advocated the building of special motor roads when

'the opportunity occurs.

Glen Etive for Nation .

GLEN ETIVE, which runs down from RannochMoor to Loch Etive, has been presented to the

nation. Part of the glen will be devoted to cattle -raising.

Young Price in NavyLT.ARRY PRICE; Jour., son of Harry Price, the" founder of the Scottish Amateur C.A., is now,serving in the 'Nasty. Both the PrieeS are members' ofthe Cambusifing C.C.

Aspden - Sergeant -major

HARRY ASPDEN, formerR.T.T.C. North Dis-

trict secretary, has beenpromoted to sergeant -major.He is serving with a RoyalEngineers unit in Scotland,and retains his interest incycling.

Successful AppealTHE Chief Constable of

Salford recentlyappealed to cyclists to -take -more care during peaktraffic periods, and sincethen only one cyclist hasbeen 'held responsible foran accident.

Cycling Vicar GainsM.B.E.

THE REV. J. N. SYKES,A 56 -year -old vicar of aStepney church, has beenawarded the M.B.E. Duringthe severe raids of Ip40-41

he cycled about the East End doing first -aid and rescuework.

Lack of BatteriesnWING to lack of batteries, a large London area`...x factory reports that 600 man-hours were lost in arecent week. Workers using bicycles to reach thefactory could not buy batteries for their lamps.

Forth Road BridgenURING February representatives of the Edinburgh.1- Town Council, and the West -Lothian and FifeCounty Councils, met in Edinburgh to discuss thequestion of a Forth road bridge as a post-war project.

Harry Price ResignsOWING to pressure of work, Harry Price, secretary

and founder of the Scottish Amateur C.A.,resigned at the recent general meeting of the Associationat Bo'ness. New secretary is Stanley Telford.. 26,Bouverie Street, Port Glasgow, Renfrewshire.

Invitation EventsAN innovation this season in Scotland will be the" holding of invitation events at 25 and 5o miles,The Scottish AmateurC.A. executive will select20 riders to ride in each ofthese events, which willbe held at the end of theseason.

Fife Champion in'Middle East

JAMES WALKER,former Fife cycling

champion, is serving atpresent with the R.A.F.in the Middle East. Notfar away, and also servingwith the R.A.F., is JohnWalker, his brother, whowas also a keen timeqialist and official.

Massed -startProposal

A P ROT OSAL that" massed:start racingshould be permitted underthe control of the ScottishAmateur C.A. was turneddown at the Association'srecent meeting. It waspointed out by the chair-man that such a proposalwould involve changesin the constitution, andbefore this happenedclubs and associationsshould be able to examine the

the Wisbech Wheelers, has died. He was 75 and cycledto church when he was married.

Old Timer's DeathQT.trzo to have won over 2,po trophies during his" career, Walter Popplewell, well-known racingenthusiast during the days of H. L. Corns, has died.He was 87 and lived at Ipswich, where he was statedto have been the first person to ride an Ordinary.

Club's RevivalTHE Lanarkshire Road Club is to be resuscitated.

Pre-war it was one of the most prominent ofScottish clubs.

Barnesbury's LossA FORTNIGHT after his wife gave birth to a son," the death was announced of Arthur lCheetham,Bamesbury C.C., as the result of enemy. Action at sea.His wife, Ethel, is a member of the Barnesbury EliteLadies' C.C.

Camden Wheelers ActiveALTHOUGH Camden Wheelers have over 54

members in the Forces, including former SecretaryTom Brown, now in Persia, they have an -ambitiousprogramme in hand. The club secretary, Reg. Dilliway,is only is years of age.

In Italian HandsFRED GILLHAM, Wisbech Wheelers, is aprisoner

of war in Italy. Several of the club's memberswere posted as. " missing " at Singapore, and no newsof them is yet to hand.

Champion in IndiaGEORGE ROSS, former champion of Liverpool

Century Road Club, is now in India with 11.1M.Forces.

Hampshire Road Club's InnovationHAMPSHIRE Road Club's annual prize.distribution

took the form of an " American Lunch." Teatwas provided but food had to be taken.

Bon Amis C.C. ActivitiesALTHOUGH the Bon Amis C.C. was not formed

until after the outbreak of the war, it has 75members, of whom 4o are serving with the Forces.

No ChangeMO change is reported in the officials of the old -

established Cheshire Road Club, which hasbeen faithfully served by zealous officials for sonicyears.

Seen by the tourist. The tablet on the birthplace at Bello. Mill,Lugar, Ayrshire of William Murdoch, inventor of gas lighting.It was erected by the North British Association of Gas Managers

-in 1913.

Clarion Training CentreJACKT TAYLOR, West of Scotland Clarion C. and

A.C., andScottish all-round champion, has set up6 training centre in Glasgow for Clarion riders. The.move is part of the Clarion C.C. campaign to stage acome -hack in Scottish racing circles.

proposition in full.

Time-trialist's MileageD. K. HARTLEY, Dukinfield C.C. who put up some

outstanding rides in 1942, cycled no fewer thani2.,o77:miles during that year. He is a police constable.

Girls for the Addiscombe. .

A DDISCOMBE C.C. now admits girls to fullmembership/ Previously they were eligible for

:associate membership only.

Died in ItalyPROMINENT member of'Wessex C.C., and consis-

tent rider in 24 -hour events, L. E. l" Ted ")Valley died while a prisoner of war in Italy.

Wisbech Wheeler?STATEDLoss-Q to he the first person in Wisbech .to owna bicycle. Mr. U. D;Palmer. vice-president of

Unique FixtureA LOW -GEAR 25 -mile time trial held on Christmas

Day attracted 37. enthusiasts. D. Ford, LondonClarion, did fastest time with a hr. so min.31 see.

Massed Racing In ScotlandDUNDEE and District Time Trials Association are

pressing for massed -start racing in Scotland.West of Scotland Clarion C.C. oppose any move tohave Clarion," either nationally or locally, involved inhelping the new British -League.


48 THE CYCLIST March, 1943

PARAGRAMS.(Continued from previous page) '

Thorpe (ynr.) in R.A.F.CLIFF THORPE, younger brother of. Len. Thorpe,

famed Barnet C.C. time-trialist, is now with theR.A.F.

Death of Old " Finsbury -Parker "MAJOR PERCY L. BREYSIG; founder member, 6o

years ago, of the Finsbury Park C.C., and clubchampion in 1887, has died. He was 76 ,,nd a pioneermilitary cyclist. He had seen active service in Egyptand Palestine.

Leicestershire's LossSHORTLY after returning from training in the.

United States, Pilot -Officer, J. Longstaff, Leicester-shire Road Club,' was killed in a flying accident.

More Youth HostelsBIRMINGHAM Regiondl Group of the Youth Hostel

Association states that two new hostels will beopened in the spring. One is at Corris, and the otherat Ludlow.

Women Racing in AustraliaMISS H. NORMAN has won the first South

Australian State five miles unpaced road champion-ship at Enfield, Australia, with the time of as mins.35 seconds. It is reported that she intends to attemptto establish several unpaced women's records inAustralia.

Northern Open EventsNso fewer thin 21 open road time trials are scheduled4..1 to be held in the North District area of theR.T.T.c. this year. North Lanes are the biggestpromotors.

. Time Trial Association DisbandedFORMED to meet war -time conditions, South

Staffordshire Time Trials Association has beendisbanded,

Barnesbury C.C.'s Fine RecordBARNESBURY C.C. has over zoo members on its

books, 6o of whom are with the Forces.

News of Norman HeyNORMAN HEY, well-known Bronte Wheeler and

prolific pre-war tin-ie-trialist, has, crossed " theline " three times. He is with the Royal Navy andsays his journeys are akin to a Cook's tour !

West Hants Road Club's LossFRANK YOUNG, keen z4 -year -old member of

West Hants Road Club, has been killed in actionwhile serving with the R.A.M.C. in the Middle East.

George Medal for Talbot WheelerQERGEAN'T P. PICK, Port Talbot Wheelers, now1-1 serving with the Royal Fusiliers, has been awardedthe George Medal for disarming and capturing anescaped military prisoner who had fatally injured amilitary policeman and another soldier. Pick, withcomplete disregard for his own safety,- entered a roomwhere the man was hidden and disarmed him.

Bar for D.F.C.WELL -known polo qpert and enthusiastic time-

trialist of Norwood Paragon C.C., FlyingOfficer H. Berridge has been awarded a bar to hisD.F.C. for devotion to duty. .

Club's InnovationLOHNSTONE WHEELERS, which presented each

serving member with a gift of los., has electedrs. Graham as president.

Old Timers Pass OnE. LAMB, organiser of the Stanley Cycle Show

from 1894-101o, has died. He was 83. Thedeath is also announced:of A. B. W. Vviatton, at the ageof 8o, a one-timamember of Cambridge University B.C.Prisoners Together

'THREE members of the Bee C.C., two of whom arebrothers; are prisoners of war together in enemy

hands. 'They are W. S. 'McKnight, C. Brigden andR. V. Brigden.Tom Hughes of Wigan'THERE are few more enthusiastic veterans than

Tom Hughes, of Wigan, who, although in his77th year, managed to accumulate over ici,000 miles ina year. Since he passed his both birthday Tom hasridden no fewer than 169,488 miles. He has been acyclist for 55 years.

Bidlake Memorial Price'THE Adjudicating Committee of the F. 'T. Bidl

Memorial Trust met recently, and afterconsideration resolved that no award be maderespect of 1942-

. Club NotesAnother Tandem sonONCASTER WHEELERS have decided to hold a1-- new tandem 5o, on a holiday date.

Bo'ness Official in ForcesJM'GREGOR, leading official of the Bo'ness C.C., .

of West Lothian, has just joined the Forces.

Lanarkshire Club Revives'THE Lanarkshire Road Club, formerly one of

Scotland's leading bodies, has been revived..

Taylor Trains NovicesJACKT TAYLOR, former Scots champion,is running

a training school for novice cyclists in Glasgow.

Third Child for Record -HolderMRS. P. SPELTINCKY, formerly Miss Peggy

Hardingharn, the record -holder, has just presentedher husband with a third child. Both Mr. and Mr..Speltincky are prominent South _Midlands club riders,with the Nomads (Hitchin) C.C. and the Bedfordshire -Road Club.

Killed in Motor -cycle Accident -

MOMMIE McMURRAY, a leading Douglas C.C.A (Glasgow) club rider of some years ago, has been

killed in a motor -cycle accident.

Midlander a Prisoner of WarQERGT. J. VAUGHAN, of the Midland C. and A.C.,`,7 is now reported a prisoner of war. He wasreported missing from air operations in November,1942.

Perkins Called , UpHENRY. PERKINS, secretary of the Northants and,

District C.A. and also time trials secretary of theBedfordshire Road Club, has reported for service withthe R.A.O.C.

Seventy Members Away'THE Douglas C.C., of Glasgow, has over 7o membersA, in the Forces, but those who remain are continuing

the club's activities. The club will promote its open25 and so events this season.

Goldberry ProgressINURING the past year, the Goldberry C.C., ofA- Kilmarnock, made good progress. At its recentannual meeting the club decided to support massed -start racing, and also to promote an open 25 miles timetrial this year.

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