Bubble sextant
Item
Title
Bubble sextant
Description
AIR MINISTRY BUBBLE SEXTANT MK. IX, REF. NO. 6B/151, SERIAL NO. 7808/40, WITH ALUMINUM STOWAGE CASE. Made of a blackened alloy finish, (Ref. No. 6B/151) first model without the clockwork attachment. The black rubber eyecup is torn from the eyepiece. The batteries are no longer present in the handle located on the left side of the sextant. Dials and levers seem to be functional. "A.M. BUBBLE SEXTANT MARK IX 6B/151, Serial No. 7808/40 BRIT PATS. 480112 490621 AND PENDING" is stamped in white on the left hand side in the bottom corner. The serial number, 7808/40, is stamped in white on the upper right side. The aluminum case, with all seams rivetted, stands 8 7/8" tall, is 7" wide, and a base depth of 6 3/4" with its cover closed. Its top is 3 1/4" deep with its cover closed, angling outward until it matches the base depth 3 1/2" above it. Rectangular alloy "rings" are rivetted to either side, through which are sewn either end of a 1" x 17 1/2" brown leather carrying handle. Rivetted to the reverse are, to either edge of its base, two aluminum extensions with stud holes. To the center of the top of the case, an identical extension is oriented upwards. These were no doubt meant to mate with wall mountings. Rivetted to its top are aluminum flanges which mate with the two brass friction clips rivetted to the upper edge of the cover. The lower edge of the cover is hinged, allowing it to open outward. Fit into a rivetted aluminum window to on the front of the cover lid is a paper card with, "Ref. No. 6B/151 BUBBLE SEXTANT MK. IX, S. S. & S. Ltd., SERIAL NO. 7808/40 INDEX CORR No.", printed on it. The interior is padded along its base, both sides, and on the inside of the cover. Two sections of padding are to extensions along the rear interior wall. Inside the case there are two metal bracket clips for a 12/24 volt plug adapter with a 80" purple braided cord attached to a two pin plug (not present).
Identifier
986.x.006
Provenance
Interest in aeronavigational instruments arose with the demonstration of the military potential of aviation during World War I, and built slowly in the 1920s. The introduction of commercial transoceanic flights in the mid-1930s, together with growing international unrest, led to increased attention to this technology. The military services purchased large numbers of these instruments in the early years of World War II, and again during the Cold War, as did commercial airlines in the post war period.
Abstract
Good
Date Created
1940