An early 20th century oxidized brass 'Bell' pattern sextant, the arc with silvered scale, signed 'Heath & Co LD Crayford London S.E', numbered '5512' and detailed 'F.H.G. Walker. R.N', fitted with magnifier, coloured filters, mirror and wood handle, complete with assorted accessories within a fitted mahogany case, the hinged lid interior displaying National Physical Laboratory certificate, dated December 1902, the hinged lid inset with a brass plaque, inscribed 'F.H.G. Walker. R.N', case width 26.4cm, with bespoke outer leather case, accompanied by original Admiralty Lord Commissioner's letter appointing Captain F.H.G Walker RN in command of H.M.S. Iron Duke, dated 22/11/34, an application form for railway ticket reduction for officers of the Navy and a Rowland Langmaid etching of 'H.M.S. Iron Duke December 1934', framed. Note: Francis Heathcote Gordon Walker (1887-1937) was a Royal Navy officer with a series of appointments in battleships and cruisers, including Magnificent, Iron Duke and Greenwich.