Pocket sextant made by Charles Augustus Schmalcalder, London, about 1830. Lacquered brass frame and limb, the detached screw-in handle is missing. Signed on the index arm: Schmalcalder | London. Polished brass scale from -2° to 134° every 30', measuring to 120° (digits are read from the pivot). Brass vernier to 1', zero at the left. There is no tangent or clamping screw; the index arm is moved by hand, by a milled knob. No shades. Index- and horizon-glass adjustment by screws and a fixed milled screw. Sight vane with one pinhole. A mahogany keystone box. Pocket brass sextant. 1825-1835
Clinometer patent by C. A. Schmalcalder, 82 Strand, London, England, 1810-1826. Patent clinometer, British, 1810-1826 1810-1826
Two prismatic magnetic compass, one with leather case, by Charles Auguste Schmalcalder, Strand, London, England, 1810-1826 Two prismatic magnetic compass, British, 1810-1826 1810-1826