Bausch and Lomb Model A Bubble Sextant

Second-generation aeronautical sextants were much more aerodynamic, lightweight, and easy to handle. H. K. Beij of the National Bureau of Standards designed this one (and many others) for the U.S. Navy.

Caption:
One of the first effective models of bubble sextant for aeronautical use.
Type: Artifact
Image Date: January 4, 1913
Credit: National Air and Space Museum, Smithsonian Institution.
Origin: National Air and Space Museum, Smithsonian Institution.
Creator: Eric Long
NASM2013-00134
 
One of the first effective models of bubble sextant for aeronautical use.