I am offering an original WWII USN PELORUS-DRIFT SIGHT built by AERIAL MACHINE & TOOL COMPANY based in New York. A Pelorus-Drift Sight is designed to function either as a Pelorus, for taking bearings on objects, or for improving dead reckoning aircraft navigation by measuring the angle between the heading and the track of an airplane. It consists of a small telescope extended vertically through the bottom of the aircraft with the eyepiece inside the navigator's station. A rectile, consisting of spaced parallel lines, is rotated until objects on the ground are seen to be moving parallel to the lines. The angle of the reticle then indicates the aircraft's drift angle due to winds aloft, which can also be used to calculate ground speed. All the components are housed in the original dove tail wood case with slide-in top. The base plate assembly has had a wood base added for display purposes. Also, the manufacturer’s tag is still attached to the base plate and the original “Instructions for Installation, Operation and Maintenance” are included. This nautical artifact is in excellent condition and is a prime example of U.S. Navy Aeronautical history. Additional Nautical Items Available - Please Call Cliff @ 760-736-8101 For More Information.