Hi!
First of all, I do not know wht it is called in english but I hope you will understand anyway.

Some ships chronometers are equipped with electric sockets, like the Ulysse Nardin in Whitneys exelent book on page,....I do not remember exactly but I think it was on page 150. What was these sockets used for?
Regards
Bernhard

Break Circuit.

Ship's chronometers were equipped with a break circuit that opened (or closed) contacts at a fixed interval. That signal could then be used to synchronize other time displays or instruments.

Here is a close-up view of the mechanism from a Russian chronometer.

Thanks a lot Tom!
/Bernhard