Smithsonian - National Museum of American History, Behring Center

Physical Sciences Collection - Navigation

Browse Makers | Browse Instruments | Index


Bubble Sextant - click to enlarge

Bubble Sextant - click to enlarge

Bubble Sextant - click to enlarge

Click image to enlarge.

Bubble Sextant

Catalogue number:

"SEXTANT–BUBBLE TYPE / BU. AERO–U.S. NAVY / AN5854-1 F.S.S.C. NO. 88-S-375 / MFG. PART NO. 29710 / MFG. SERIAL NO. VZ 3538 / CONTRACT NO. A(s) 539 / BAUSCH & LOMB OPTICAL CO. / ROCHESTER, N.Y. U.S.A." and "U.S. PATENT 1,674,550 2,306,874 PAT. PENDING"

Bausch & Lomb made this instrument for the U.S. Army and Navy in the latter years of World War II. It was rugged, compact, and easy to balance. It had an electric light for standard illumination, and radium for low intensity illumination. Its 15-shot median device was simple and self-explanatory, and offered "a fool-proof visual average, which is easily understandable to the navigator."

Ref: Operation, Service, and Overhaul Instructions with Part Catalog for Bubble Sextant, Army Type AN-5854-1, Navy Model F.S.S.C. 88-S-375 (Louisville, Ky., 1945).

E. L. Flint, "Liquid Level," U.S. patent #2,306,874.

E. L. Flint, "Use of the Bubble Sextant," Aero Digest (April 1946).

Further Information:

Bausch & Lomb
Aircraft Sextant