PIKE-PREVENTION 153

SUGGESTIONS FOR FIRE-PREVENTION AS A PROGRAM FORGENERAL SCIENCE CLASSES.

BY FRED T. HART,John Marshall High School, Chicago^ III.

Many of the states are asking the public schools to have aday or two set aside for the study of fire-prevention. The logi-cal place to study the details is in the classes of General Science.I have had much success with the following material, and theclass has shown a good deal of interest in it. It has been givenas an assignment for two or three days.The loss by fire in this country is enormous, and part of it

has to be borne by every boy and girl. . A noted educator oncesaid that every boy and girl who would be a good citizen shouldlearn to protect his community and country against loss by fire.If we are to do this, we should study the causes of fire and afew principles of fire-protection.

CAUSES OF F^RES.Carelessness. This is the greatest cause of fire, as shown

by accurate statistics. You could make a long list of the carelessthings that you have done and that you have seen other peopledo, which lead to fires. A few of the outstanding causes due tocarelessness aye the use of matches, the unrepaired chimney, theflimsy goods we use for dress and decoration, the careless useof inflammable materials. The efficiency chart below will giveyou the twenty-five most common causes of fires in the cities.

Matches. There are two general types of matches upon themarket; the common parlor match, and the safety match. Par-lor matches are the most dangerous because they can be lightedon any surface which will give a slight friction. Small childrencan ignite them very readily. Parlor matches left on the floormight start trouble. If they are stepped on, fire may be pro-duced. Mice can carry these matches between the walls andunderneath the floors. Their nest might be near a chimney orthe warm furnace pipes. These conditions have often causeddangerous and destructive fires.The safety matches have the advantage in that they do not

ignite so readily and cannot be started on any surface. Factsof this nature should be considered, especially in the homeswhere there are children.

Spontaneous Combustion. This is a condition where the firestarts without direct ignition. It is caused by a chemical actionwhich starts very slowly, and grows faster until it generates

154 SCHOOL SCIENCE AND MATHEMATICS

enough heat to reach the kindling temperature of the materialconcerned. It is hard to guard against, because there is gen-erally no one around when the action starts. Some of the com-mon causes of fire of this nature are collection of oily rags inclosets, rubbish in heaps, large coal piles, and newly mown hay.Preventives of spontaneous combustion are good ventilationand cleanliness.

Experiment. To illustrate spontaneous combustion: Placea small piece of yellow phosphorus, the size of a pea, in a testtube containing about 3 c. c. of carbon disulphide. Roll afilter paper so that it will slip into the tube. Saturate one endof the filter paper with this solution. Unroll and lay the paperin an iron plate. Watch the action. The carbon disulphidetube must be stoppered and set aside.

Explain that this very thing may happen with certain oilssuch as are used by painters, and with furniture polishes.

COMBUSTIBLE AND NON-COMBUSTIBLE MATERIALS.Substances that can take fire and burn readily are combusti-

ble. The following materials have been known to cause manyfires on account of their low kindling temperatures: phosphorus,artificial and natural gases, acetylene, gasoline, kerosene, flimsy.cotton and woolen-goods, celluloid, turpentine, and paints.

Materials that are non-combustible and are used againstfire are-asbestos, concrete, metals, stone, slate, etc.

Experiment. Combustible Substances: Kindling Temperature.Place small amounts of sulphur, phosphorus, wood, clean sand,concrete, short distances apart on an iron plate. Start gentlywith the bunsen burner and then use the full flame against thepan. Questions. Which combustible substance has the lowestkindling temperature? Which the highest? What is necessaryto make a substance burn? Compare wood, sandstone, andconcrete as fire-proof materials for building.

Asbestos. Heat asbestos, cotton, and wool and explain theasbestos curtain and asbestos enclosures for moving picturemachines.Demonstrate the soda-acid fire-extinguisher. Generate carbon

dioxide. Place a candle down at the bottom of a trough, andlet the gas flow down this incline to the candle. Note whathappens.

FIRE EXTINGUISHERS.Fire extinguishers are of two general types. The soda-acid

extinguisher consists of a very strong tank which contains soda

FJRE’PREVENTION 155

in solution and a jar of sulphuric acid. The directions on thetank tell you how to use it. Carry the tank to the fire in anupright position, and as you approach the fire turn upside down.This causes the acid to mix with the soda solution. The result isa rapid chemical action which generates a large amount of carbondioxide gas. The formation of this carbon dioxide creates ahigh pressure, which forces the water and the gas out throughthe attached hose. Carbon dioxide is a very heavy non-com-bustible gas, and acts as a blanket which settles down over thefire and shuts off the supply of oxygen.The carbon-tetrachloride extinguisher is generally a pump

affair’ containing the liquid which forms a vapor that is non-combustible. It is very efficient in putting out grease, gasolineand electrical fires, where the application of water is very un-desirable.

Experiment. Use of carbon tetrachloride: Make a simplesquirt gun and fill it with carbon tetrachloride. Make a fireof rags covered’with oils. Try to put the fire out with water.Repeat, using small-amounts of the carbon tetrachloride inthe squirt gun. Discuss results. What types of fires are difficultto extinguish by. use of water? What are the advantages ofthe carbon-tetrachloride fire extinguisher?

GENERAL PRINCIPLES OF FIRE FIGHTING.Oxygen is necessary for burning, and the knowledge of this

fact will guide one in the early stage of the fire. The fire shouldbe smothered, if possible, and all drafts shut off. For example,the housewife who is in contact with a gasoline or grease fireshould not run to the open door and fan the blaze, but shoulduse some means of covering the blaze and shut off the supply ofoxygen.An experiment should be given with gasoline to show how

easily it is smothered by a blanket or an old coat. The gasolineshould be in a vessel so that the liquid will not spread.

Before any substance will start burning it must reach itskindling temperature. This principle should be taught as a veryimportant one in the prevention of fires. Water puts out a firebecause it shuts off the supply of oxygen and keeps the tem-perature below that of the kindling point.A USEFUL CHART TO AROUSE INTEREST IN FIRE PREVENTION.The following chart is used in this way. A copy is given to

each pupil and he is directed to take it home, and fill the blanksin the presence of his parents. The parents sign it and the

156 SCHOOL SCIENCE AND MATHEMATICS

pupils bring the chart back the next day. At this time eachpoint is discussed and the principle of the topic is impressedupon the student^ mind.A master chart is then made from these reports to show the

cause of most of the fires in the local district.

GENERAL SCIENCE.Fire Prevention Efficiency Chart.

To the student: Answer the following questions by the words "yes" or"no." If you ,use the word "no," put 4 per cent to the right of the word.When you have finished answering the twenty-five questions, add thenumbers. This sum is the per cent of efficiency of your home, as to fireprevention.

1. Do you use the common parlor matches at home? ...-.-.....- .�-...�.

2. Do you use candles? . .....--...-. .......-.--.

3. Do you use kerosene for lights? ....-�.-.. ..��.--.

4. Do you put dirty, oily rags in a wooden container?...........- ............

5. Do you use gasolene for any purpose? ...-.-�-.. .-...-.�.

6. Is the gasolene within twenty feet of the house? .-.��..- -..--..-.-..

7. Does the gasolene can lack red paint? -.-.�.-.-. ...-.....--.

8. Are any of the gas connections made of rubber? .�.-..-.-. -�.--�..

9. Is the fire place dirty? ............ ........�.

10. Does the woodwork around the stove lack metalprotection? ..-.-..-.- .-...-..�.

11. Have you ever seen your parents hunt for a gasleak with a match? ’ ............ .-.-..-..-..

12. Have you a wooden ash pail? �

..��.-.- .�.�....

13. Do your parents dry clothes within two feet of thestove? -.--.-.-.. ...�.-�.

14. Have you any open gas jets7 ............ ............

15. Is the roof of your house made of combustiblematerial? ..�-�.� ..--...-.�

16. Have you ever seen your parents use any liquidcleaning compound in the house? - .-.��� ..-.�...-.

17. Have you ever seen your parents thaw water pipeswith fire? --:.-..-.. ...--.-.....

18. Have you any loose rubbish in the basement? ��-.-.. ............

19. Have you any loose rubbish in the attic? �.�.�-. .�...-..-.

20. Have you seen any loose wire insulation? -..-...� ............

21. Does the garage show any signs of grease? .-.-.-..-. ...-...�..

22. Does your yard contain dry leaves or rubbish? .��..�. ............

23. Does any member of the family smoke in thehouse? -..-..-..-.- .-...-.-:.-

24. Have you mice in the house? ..�.-.� ....,�-.-.

25. Are you ignorant on the method’of ringing a firealarm?

^

’- ’ ............ .....-..�.

Efficiency ’

, -.....-.-.. ......�...The average home is about 70 per cent efficient. Many are below this

mark. We should be nearer the 100 per cent mark.Carelessness is the great cause of fires.Vienna and Chicago are cities of about the same size. Vienna had a

fire loss of about ^303,200; Chicago for the same year $5,513,237. If youare careful in making out your chart, I. think it will tell you the causeof such a large loss in Chicago.