Protractor, Aircraft Navigation Plotter, US Naval Observatory PZL and the scope is ~8

and the scope is ~8 inches long

(see description of this system and its components in the photo gallery)

The indicator has two pointers

In the servoed mode

Protractor, Aircraft Navigation Plotter, US Naval Observatory PZL and the scope is ~8This is a WWII era Aircraft Navigational Protractor (aka Aircraft Plotter) Kit as used in navigator crewed aircraft of the US Army and Navy. This particular protractor has a tag from the US Naval Observatory stamped 1945. It would be fitted to the navigators map table to plot and revised the aircraft's course. The kit appears to be complete. Included with the protractor machine itself are two steel rulers in cardboard sheaths which attach to the