Simple theodolite, with box, trade card and brass parts, by James Search of London, 1771-1781
Simple theodolites such as the circumferentor (with a full circle scale) and graphometer (with a half-circle scale) were widely used throughout the 17th and 18th centuries for angle measurement. A joint on the support allowed for both vertical and horizontal use. The tradecard on the box lid indicates that this circumferentor was made by James Search (active 1771-1781), a Mathematical, Philosophical and Optical Instrument maker who made and repaired instruments 'At the Globe in Crown Court, St Ann's Soho, London'.
Box with trade card label and parts for simple theodolite, by James Search, London, 1771-1781
Simple theodolite, by James Search of London, 1771-1781
Circumferentors (with a full circle scale) and graphometers (with a half-circle scale) were widely used throughout the 17th and 18th centuries for angle measurement. A joint on the support allowed for both vertical and horizontal use. The tradecard on the box lid reads: 'Mathematical/ Philosophical and Optical/ INSTRUMENTS/ Made and Repaird in the best Manner/ At the Globe in Crown Court, St Ann's Soho,/ London/ BY/ James Search, Instrument Maker'.
