Charles and Anne Morrow Lindbergh used this instrument in 1933 when they
surveyed air routes across and around the Atlantic for Pan American Airways.
Anne had recently studied celestial navigation, and the notes on the back are
probably in her hand. The serial numbers indicate that this was the third
example of the Model 342, and the third one made for the Navy in 1931.
Ref: "Recent Developments in Pioneer Aircraft Instruments," Aviation Engineering 7 (Oct. 1932): 16-17.
Victor E. Carbonara, "Navigating Instrument," U.S. patent
#1,970,543.
Victor E. Carbonara, "Sextant," U.S. design patent #85,912.
A. Scott Berg, Lindbergh (New York, 1998).
