Bubble Sextant MK IXA (instrument and case)
Donor: Harry Drader, 2004
The Bubble Sextant MK IXA was an aerial navigation device used in WWII. Where a normal sextant device requires an observer to be parallel to the horizon, the bubble sextant creates an artificial horizon that allows the observer to use the device in situations where the observer cannot be parallel. This is especially important in aeronautical navigation as the observer cannot always rely on flat surfaces, such as the ocean, for reference. The bubble sextant was first manufactured in the 1920s with the rise of aerial travel, eventually becoming an essential tool used in aerial combat during the Second World War.