L4514-001

Azimuth compass Long Caption: The compass was designed by Ralph Walker, a resident of Jamaica. It was intended as a solution to the longitude problem and the idea was put to the Board of Longitude in 1793. The idea was to use magnetic variation (which was known to vary according to geographical position) as a means of determining longitude. Walker's proposal consisted of a compass with a sun-attachment for indicating the true direction, with which the magnetic compass's reading could be compared to find the variation. Walker's compasses were sent for trial on the 'Invincible', 'Glory' and 'Lynx' in 1794, but proved unsuitable for determining longitude. Nevertheless, they received considerable praise as compasses and were adopted for the Royal Navy the following year, but proved expensive and officers found them difficult to use, although the Royal Academy at Portsmouth offered instruction in their use. They were therefore only supplied to ships in which the Captain or Master could prove that they understood how to use them. In 1819, the Navy decided to stop buying the compasses. Credit line: © National Maritime Museum, Greenwich London Object: NAV0263 Artist: Ralph Walker Date: circa 1793 Click here to buy a bespoke print of this image.