A large mahogany 'A' framed quadrant, 18in. (46cm.) radius, the cross member with inset ivory plaque, signed 'Made by J.N.O. Gilbert on Tower Hill, London for Thos. Hare, August 25. 1763', the box scale divided 0° - 90°, with pinhole sight and horizon mirror and lower horizon mirror (missing upper horizon and index mirrors)