Components from the three-foot geodetic theodolite, sometimes called the ‘great Theodolite’, used for the Principal Triangulation of Great Britain. Made by Jesse Ramsden, Piccadilly, London, 1791. Components consist of: 3 lamp microscope housings; 2 oil lamps with condensing lens; small oil lamp (without case); oil lamp brackets plus 2 lamp covers; clamp and sector clamp; telescope dust cap with apertures; 2 curved double bracket pieces; 1 single bracket piece; flange disc; 7 eyepieces; 1 filter; 1 right-angled eyepiece; dust cap; brush; 4 microscope illuminating mirrors and an assortment of bolts and fittings.