Pocket brass framed sextant

Pocket sextant, with mahogany keystone box, made by Jesse Ramsden, Piccadilly, London, England, 1785-1795. Polished brass frame and limb, no handle. Signed on the crossbar: ‘Ramsden London’. Brass scale from -2° to 145° every 30', measuring to 125° (digits read from the pivot). Brass vernier to 1', zero at the left. The tangent screw is on the front of the index arm; the clamping screw is on the back. Two shades (both red); no horizon shades. Index-glass adjustment by screw; adjustment of the horizon glass by fixed milled screw and by Dollond's extended lever and clamp, operated from beneath the telescope bracket. Detached telescope bracket, to be fit to the frame by a dovetail mount; perpendicular adjustment by rising-piece and a milled screw. Detached magnifier on a 35-mm swivelling arm. Telescope (62 mm) erect image. Shaded eyepiece (red).