W.C. Cox Double Frame Sextant
Enameled brass strait-bar pattern pillar frame , wooden handle. Signed on the scale W.C. Cox, Devonport. Silvered scale from -5 to 140 by 10'. Silver vernier to 10'', zero at right. Index glass adjustment by screw, horizon glass by detachable milled knob and flange screw. Tangent screw and clamp on the back of the index arm. Four sun shades , three horizon shades . Magnifier mounted on 11 inch index arm. Telescope bracket in two parts, fitted for correcting collimation error, perpendicular adjustment by rising piece and milled knob. Four telescope site tubes, two filters and one adjustment tool. In mahogany keystone box. Circa 1822-1857.