Aircraft Bubble Sextant Type MA-2 Commemorative Display F6F Hellcat Here is a Type C

Here is a Type C Altimeter used in early military aircraft of the US Army Air Service during WWI

The left knob adjusts the indexing 'aircraft' within the dial to align the perspective of the pilot to the horizon indicator

Some pencil markings

The main pointer rotates clockwise as the airspeed increases

Aircraft Bubble Sextant Type MA-2 Commemorative Display F6F Hellcat Here is a Type CThis is an Aircraft Bubble Sextant Type MA 2 elegantly mounted on a hefty wooden base with brass plaques dedicated to its recipient, pilot Colonel Melvin P. Clark, by appreciative navigators of the 323rd Flying Training Wing at Mather Air Force Base near Sacramento CA in 1978, where he was base commander. The sextant, made in 1957, swivels on the wooden base to permit viewing of all angles. The knobs on the sextant turn, but its operating condition is