Quite rare; a 4.5 inch nickel silver double arm protractor by Piggott, London, with geared adjustment via a thumb-wheel, the swining arms with pointers and steel springs (one missing), divided from 0 – 360 down to a half degree, the vernier reading to 15 arc seconds. The reverse engraved with previous owners name, ‘H. Stone’. Contained in original mahogany case 13.5 x 13.5 cms with two fastening hooks.
Probably either George or Peter Piggott with a combined working range date from 1816 – 1859.