Scientific Instruments > Drawing Instruments

Napier Pocket Compass In Original Case Made by Threadwell.

Item#: SDI218



Napier Pocket Compass, ‘Swiss Pattern’ Type By Threadwell. This is the most compact of all drawing instruments, a true mechanical work of art. Produced in England by Threadwell, the small tools engineering company and made from German silver (electrum) with the legs folding up into the upper part. Here, the swivel joint is made in the same plane as the head joint. This arrangement may provide a compact combination of two needle pointed heads for use as dividers for marking off distances, or one pointed head and an ink or pencil head for use as a compass. The compass is marked 'Threadwell' and also has the broad arrow of the British acceptance mark. Comes in its original silk and felt-lined case 8 cm (3 ¼ inch) long. David Napier (1790 – 1876) is considered to have invented the folding compass in 1848.