Timing devices for clocks or watches for comparing the rate of the oscillating member with a standard

Full Title

Measuring, counting, calibrating, testing, or regulating apparatus > Timing devices for clocks or watches for comparing the rate of the oscillating member with a standard

Classification Context

Section:

PHYSICS

Class:

HOROLOGY

Subclass:

APPARATUS OR TOOLS SPECIALLY DESIGNED FOR MAKING OR MAINTAINING CLOCKS OR WATCHES