The Breitling Chronomat manual and some links
|
My dad (Niel Jonas) wearing his Breitling Chronomat in the army.
|
The Breitling Chronomat is unique for the circular slide rule.
Mine is a bit scratched so here's a nicer photo from
Chronomat history
as well as this delightfully enthusiastic description:
The Breitling Chronomat with its rotating slide-rule was patented in 1941
as war raged through Europe and other parts of the world,
its design offering a welcome respite from the plethora of military and military-inspired watches of the period.
The Chronomat's emphasis on engineering and mathematics, science and industry
seemed to offer hope for a future when the war would be over and reconstruction could begin.
To summarize the manual for the 'Type 42' circular slide-rule:
- The outer CI scale is read CCW and is marked
- telemetre at 1.2 for
the speed of sound (1,236 kilometers per hour).
- at Pi
- The inner D scale is read CW and is marked
- red "S" at 3.6 (for 360 seconds) at top dead center
- with a red arrow and red "H" at 1.0 (at the 26.6 second mark)
- red "minutes" at 6.0 (for 60 seconds)
The Navitimer's 'Type 52' slide-rule
is different
-
inner (face) has concentric scales for
- hours 1-12
- 60 seconds (in 1/5 second ticks)
- slide rule D scale
- 6.0 at top dead center, '1' around 13 seconds
- "NAUT" at 3.3
- "STAT" at 3.8
- "KM" AT 6.1
- outer C slide rule scale (also read cw)
- later
versions have red triangles
on the inner dial for 1.0, 3.3 "NAUT", 3.6 (probably for 360), 3.8 "STAT", 6.1 "KM"
outer dial (ALSO read CW): 1.0 3.6 6.0
- is intended to match the
E6B Flight Computer
Differences in the slide rules:
- The Chronomat's inner "D" scale has 360 at the top,
the moving outer scale is "CI" (inverted single decade counter-clockwise)
- The Navitimer's inner "D" scale has 60 at the top,
the moving outer scale is "C" (single decade clockwise)
- Chronomat history
shows other Chronomats with 1.0 top dead center (near the bottom: 1973, 1975)
Since the stop watch's second hand extends all the way to the slide rule,
I figure there's got to be some method of setting the outer ring
so the second hand acts like the cursor of a circular slide rule
to point directly to some calculation.
Does anyone have directions for that?
Here's the manual for the Breitling Chronomat sliderule:
other links: