Hi all,
Anybody who knows what purpose this stop watch once had? It makes one revolution in 6 sec's and beats 50/sec. As can be seen it also has a split second's function. It looks as if it is from the 20's, and I suspect it once had a military use, of which I don't know anything.

Thanks for the image of your interesting stop-watch. I think the Semikrograph was made by BREITLING of GENEVE. This model is also found with German retailer's names on lower edge of the dial and a small script letter with a crown stamped into the center of the back, which indicates issue to German forces in World War One.

A stop watch identical to yours is pictured in Konrad Knirims book; Militäruhren / Military Timepieces 150 Years Watches and Clocks of German Forces:

quote:

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http://home.t-online.de/home/konrad.knirim/

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In correspondence with Mr. Knirim, we were unable to find the exact use of this timer by the forces of Germany. However, timers of this sort have been used for such things as aerial bomb timing, air navigation and testing munitions. Other scientific non-military applications are also possible. So far, I have only seen two Semikrographs and they were both German military issue.

Are there any little markings on the back of the case of your timer?

Best regards,
Greg

Greg,
thanx for answering! The ferrous case is marked "E&M 1453" on the back. Mvt is only marked with the pat. nr you see on the dial. No markings under the dial.
The chronograph mechanism is also quite unusual; it works as a stop watch, where the balance is halted. In order to get the balance with its very heavy hair spring started again after stopping, there are TWO arms working in succession on the serrated edge of the balance. Otherwise the chrono mech looks like a normal chronograph, as opposed to a stop watch.

Are there any patent literature experts in the chapter? Is the symbol on the dial after the text "Pat." a mark to indicate Swiss patent 73392 from 1893?