Tachometer, Victometer Centrifugal, 1920s USSR The glass is intact

The glass is intact

made by Bendix and labeled for engines #1 & #2 and 3 & #4

receiving ground signal from a selected transmitter via its loop antenna mounted top or bottom of the fuselage (see photo of an example of the loop antenna)

Likely made by Horn

such as the B-17 Flying Fortress (see image illustrating the location of the co-pilot's regulator from the B-17F flight manual dated 1943)

Tachometer, Victometer Centrifugal, 1920s USSR The glass is intactThis is a WWI or Post WWI vintage aircraft or laboratory tachometer "Victometer" made by the Jos W Jones Co. This is a centrifugal tachometer: as the rotation of the engine shaft rotates a cable attached to the case, flyweights rotate around an internal axis. The weights move outwardly due to centrifugal force, which pull a brace attached to the spring loaded pointer. As the brace is pulled by the centrifugal force of the weights, the pointer is