slide rule wrist watches 3
TRANSCRIPT
Slide Rule Wrist Watches
ByBob Adams
IM 2010, Leiden The Netherlands
A simple concept
First Slide Rule Watch
Meyrat & Perdrizet Circa beginning
19th Century
First Slide Rule Wristwatch
Mimo-Loga, Juvenia and the Breitling1940’s patent
Types of Slide Rule Wrist Watch 1
Calculating Watches
Ventura
Types of Slide Rule Wrist Watch 2
Aviator Watches
To replicate the E6-B functions
Time Speed Scale and Conversion marks
Types of Slide Rule Wrist Watch 2 cont…
Examples
Breitling Navitimer with 9-hour speed scale.
(Note: not all Navitimers have this scale)
Time Speed Scales 1
• Align 16 on the outer scale with the speed index
• 24 on the outer scale corresponds to "1:30" on the inner scale• Thus the answer is 1 hour and 30 minutes
Obtain the time required for the flight of an aircraft at 160 knots for 240 nautical miles.
Time Speed Scales 2
• Align 25 on the outer scale with “1.40” on the inner scale
• The speed index corresponds to 15 on the outer scale• Thus, the air speed for the flight is 150 knots
Obtain the knots speed for 250 nautical miles with a flight time of 1 hour and 40 minutes
Scales 1
C and D scales
CI scale
Time Speed Scale
Scales 2
Trigonometric Scale
Gauge Marks
Category Gauge Mark Value
Distance Nautical Mile 660 or 327
Statute Mile 760 or 380
Kilometre 1222 or 611
Fuel Litres 485
Fuel Lbs 766
Oil Lbs 960
Imperial Gallon 1065
US Gallon 1280
Mathematical Pi 3.14
Seconds 360
Lbs 3630
Kgm 1623
Feet 1430
Metres 4360
Cursors
Seiko 6138-7000
Rare
Index Mark
Calculating Watches
Index Mark is 1 positioned at the 12 o’clock position
Index Mark
Aviator Watches
Index Mark is 6 positioned at the 12 o’clock position
AccuracyVariable
Some good
Some not so good
Evolution
Thank You