Dating vintage chronographs

Dan S

Shock protection can also provide a hint.

Pianotuna

OF members, a question posed by my recent acquisition of a Pierce chronograph which I believe to be a mid 1940’s model rather than the c.1950 listed in its advertisement. The tachymetre runs only to ‘800’ and thus the main question, does the tachymetre and/or sub-dials, provide accurate guidance as to a watch’s age in the absence of reliable company data?
For example the earlier Pierce chronograph (130) had an inner spiral index that only ran to ‘400’ or ‘500’. The early 134’s similarly.
As land and airspeed records continued to tumble in those heady days did watch manufacturers adjust their dials to suit? With Yeager breaking the sound barrier in 1947 did that sensational aviation record force a rethink among watch makers who with their chronographs were targeting this very industry?
I believe Breitling for instance, from 1947 put three-minute markers on sub dials so one could keep a track of the cost of trans-Atlantic calls.
Just curious on the matter. Appreciate anyone’s input.

just a pic to illustrate. M

Vitezi

The seminal reference book Chronograph Wristwatches: To Stop Time by Lang and Meis suggests that, in general terms, the highest speed reading on the tachymeter scale can be used as a means of dating a chronograph.

Chronographs made in the 1920s have scales that reach 300-360kph; in the thirties, scales reach 400, and by 1940 scales of 500 can be found. By 1950, top numbers were 750-800, in line with the increasing speeds of automobiles and aircraft. At 800, your example is about right for the 1950s and is consistent with the dial and case style.

Joe_A

Dan, apart from Dr. Roland Ranfft, can you share any sources where one can learn during which year a manufacturer of movements switched from and early attempt at shock-proofing to Incabloc?

I've been trying to pin down when Excelsior Park made the switch, but so far have not found anything helpful.

Information on Pierce can be found here:

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&&2uswk

Out of TIME!

Re-Read the Dial!
TELEMETRE!
For Artilere sound timing.
When you here the sound, than feel or see the explosion clock it read the correct scale to get distance.
Not sure of the formula but sure itis on line in some form. May help to date the watch also.
Instruments for WAR.... that lead to a bang & A Boom!
I won't look it up in my references, not worth my time.
Sorry Mike

Pianotuna

Thank you for the reply, I will adjust my thinking on the date accordingly. Is the book a ‘quiet read’ kind of thing or a text book for the more learned and technically minded?

Out of TIME!

Pianotuna

OF members, a question posed by my recent acquisition of a Pierce chronograph which I believe to be a mid 1940’s model rather than the c.1950 listed in its advertisement. The tachymetre runs only to ‘800’ and thus the main question, does the tachymetre and/or sub-dials, provide accurate guidance as to a watch’s age in the absence of reliable company data?
For example the earlier Pierce chronograph (130) had an inner spiral index that only ran to ‘400’ or ‘500’. The early 134’s similarly.
As land and airspeed records continued to tumble in those heady days did watch manufacturers adjust their dials to suit? With Yeager breaking the sound barrier in 1947 did that sensational aviation record force a rethink among watch makers who with their chronographs were targeting this very industry?
I believe Breitling for instance, from 1947 put three-minute markers on sub dials so one could keep a track of the cost of trans-Atlantic calls.
Just curious on the matter. Appreciate anyone’s input.

just a pic to illustrate. M