Sextant made by Spencer, Browning and Rust
Maker
Spencer, Browning and Rust
(British, 1784 - 1840)
Date1784-1840
Object number00006886
NameSextant
MediumBrass, glass, metal
DimensionsOverall: 110 x 265 x 240 mm, 1.65 kg
Display Dimensions: 110 x 265 x 240 mm
Display Dimensions: 110 x 265 x 240 mm
ClassificationsTools and equipment
Credit LineANMM Collection
Purchased with USA Bicentennial Gift funds
DescriptionThis brass sextant was made by Spencer, Browning and Rust of London.HistoryThe sextant was developed in 1757. It is an instrument of double reflection by means of two mirrors, and thus although its actual arc subtends an angle of 60 degrees (1/6th of a circle - hence the name sextant), it is capable of measuring angles up to 120 degrees. The sextant was an improvement on the earlier quadrant, an instrument capable for measuring angles up to 90 degrees (1/4th of a circle hence the name quadrant). The capacity of sextants to read angles greater than 90 degrees was an advantage when using the lunar distance method to determine longitude. This was also useful for taking horizontal angles.
SignificanceThis sextant is representative of the high level of technological development achieved in the design and manufacture of navigational instruments in the 19th century.
Parent (child)/Child (parent)