Chronograph

Chronograph, an apparatus for automatic recording of time on kymographic records (see illustration). At the suggestion of Dr. Jacquet, first constructed by the firm Boulitte in Paris. It contains a clock mechanism, one of the gears of which is provided with a cam that raises a light lever once per second, connected to an aluminum feather located on the upper face of the chronograph; switching to another gear gives raising of the feather every 1/5 of a second. The feather serves not only as a recording device but also as a conductor of current between two contacts: at the moment of raising, the circuit is broken. Thus the chronograph can also be used as a rhythmic current interrupter (through 3/5 and 1/5 sec.). On the side face of the chronograph is embedded a dial with second and minute hands; the latter are in constant motion during the entire operation of the chronograph, but from any position they can be brought to zero by pressing a special lever. Price about 80 gold rubles. A variant of the chronograph provides marks at 10, 30, and 60 seconds.