Compass, Direct Reading Magnetic, US Navy Mark X P-80 The pendulum is geared to

The pendulum is geared to a pointer which revolves in a limited arc on a dial calibrated through the range from zero (level) to 30 degrees nose up or down

Embossed on the face (black-on-black) is AC USArmy (Air Corps)

made by Aerosonic part number RC60V10 for Cessna

It also has the USN stock # of R88-I-1331

and curious

Compass, Direct Reading Magnetic, US Navy Mark X P-80 The pendulum is geared toThis WWII era Direct Reading Magnetic Compass Mark X, Kollsman 398 01 2702 was made for aircraft of the US Navy such as the seaplane JRF 5 Grumman Goose. The interesting aspect of the design of this compass is that the directional mechanism lies horizontally within the rear chamber, and displays the direction on a vertically mounted compass card. In addition, the desired course heading can be selected by rotating the knob at the bottom center of the