Engraved in script on the silver inlaid arc "Heath & Co LTD. Crayford. London." and "C. M. Blackman R. N.". The case measures 11 inches x 10 1/2 inches by 5 inches and carries an ivory tag that reads "Bell Pattern (No. 1) Sextant.". The sextant has patinated brass with an ebony handle and silver inlaid graduated scale. It includes four telescopes, ocular shifting apparatus, adjusting pin, sun filters, a swing-away vernier magnifier and bottom lock to keep the instrument secure in the case. The sextant has a proof label in the case lid by Kelvin & Hughes dated "20.4.55". The previous owner Captain C. M. Blackman was with the Royal Navy Mediterranean Fleet First Destroyer Flotilla, "GRENVILLE" in 1937. In May 1941, Captain C. M. Blackman DSO, Captain of the "EDINBURGH" was named a Commodore Second Class to temporarily command the 18th Cruiser Squadron.

Fine. The instrument has seen little, if any use, and is in working condition. The original case shows minor wear, and carries the engraved plaque, "C. M. Blackman R. N.".