Click image to enlarge.

Bubble Sextant

Catalogue number:
NASM 1963-79

Inscriptions:
"AIRCRAFT OCTANT / PATENTS PENDING / PIONEER INSTRUMENT CO. / BROOKLYN, NEW YORK" and "AIRCRAFT OCTANT / MARK III MODEL 3 / BU. OF AERO. U.S. NAVY / SER. NO. ORDER NO. / PIONEER INSTRUMENT COMPANY / BROOKLYN, N.Y."

Discussion:
This was made after Carbonara filed his patent application in 1931 and before the patent was issued in August 1934. It is identical to the original Model 342, but here the eyepiece rotates around a vertical axis so that sights can easily be taken in any direction. The U.S. Naval Observatory transferred it to the Smithsonian in 1948.

Ref: "Recent Developments in Pioneer Aircraft Instruments," Aviation Engineering 7 (Oct. 1932): 16-17.

Pioneer Instrument Company, Aircraft Octant Mark III - Model 3 (Brooklyn, N.Y., n.d.).

Victor E. Carbonara, "Navigating Instrument," U.S. patent #1,970,543.

Victor E. Carbonara, "Sextant," U.S. design patent #85,912.

Further Information:

Pioneer
Aircraft Sextant