Form watch by Richard Masterson, The Royal Exchange, London c.1630. Oval case made of silver, cast in the form of a cockle-shell, with raised ridges on both sides of the case, radiating from the case joint. Shutter for winding hole, made of plain silver.

Plain silver dial with small engraved hour circle and steel hour hand. Verge escapement, with steel two arm balance. Pinned-on, pierced and engraved balance cock. Ratchet wheel set-up for mainspring. Three wheel train. Fusee with gut-line. Back plate with engraved border, and signed ‘Ri Masterson at the Exchange Fecit’.

Masterson was a free Clothworker. He became an Assistant of the Clockmakers’ in 1633 and Master in 1642. His widow continued his business after his death in 1653. An almost identical watch by Masterson is in the collection of the British Museum (inventory number 1958,1201.2301)

Clockmakers' Museum No. 14