Gyrosyn Compass C-2A Sperry Master Indicator 653894-6B C-119 Boxcar USAF P-2 Neptune Also note the photo of

Also note the photo of the fuel tank locations in a B-36H with their capacities in gallons (note that the gages indicate fuel in pounds

Here is a WW2-vintage electrical Free Air Temperature Indicator

The P-38 had two fuel quantity indicators

which existed with that name from 1918-1926 until it was renamed Air Corps US Army

Gyrosyn Compass C-2A Sperry Master Indicator 653894-6B C-119 Boxcar USAF P-2 Neptune Also note the photo ofThis is a Gyrosyn Compass Master Indicator Type C 2A made by Sperry part number 653894 6B. The Master Indicator was part of a 5 module system combining the functions of a directional indicator and a magnetic compass, introduced in the late 1940's. See the diagram of the system with an explation of its function in the photo gallery, including a diagram of this specific indicator. An illustration of its position on an instrument panel is in the photos