Compass, Direct Reading Magnetic / Direction Indicator, US Navy

This WWII-era Direct Reading Magnetic Compass/Direction Indicator Mark X, Kollsman 398C-01 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 dial, which turns the double-arrow pointer clockwise or counter-clockwise.  The single pointer would indicate true magnetic north.  There are adjustment screws for E-W and N-S for calibration alongside the course setting knob.  See Kollsman diagram in photo gallery.

This example is in reasonable cosmetic condition given its age. The single pointer and course setting arrow rotate, and there is damping fluid in the compass bowl. The lamp is missing from its location in the upper right corner. It is mounted in a metal bracket.