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“BUBBLE SEXTANT / U.S. NAVY / BUREAU OF STANDARDS / MODEL NO. 2 / 1924 / NO. 4”
This instrument was developed for the Navy by the Aeronautical Instrument
Section of the National Bureau of Standards in 1924, and produced by the Bausch
& Lomb Optical Co. P. V. H. Weems, who donated this example to the
Smithsonian, noted that "Six sextants were made at the time for $250,000
each. Bausch & Lomb lost money on the deal but naturally recuperated on
later orders and on later models. I drew this sextant from the storeroom in
North Island, at the Naval Air Station, San Diego, and made numerous tests with
it, along with Byrd, Lindbergh, Ellsworth, etc. etc."
Bausch & Lomb