19th Century Brass Sextant with Dovetailed Mahogany Keystone Box

A British made, mid 19th century brass sextant imported and sold by Jos. Roper Optician, St. Johns N.F. (Newfoundland Canada). Graduated silver arc and vernier, with original black-coated brass frame and fittings in a unique eyeglass-shaped (spectacles) sextant design. Engraved on arc “JOS. ROPER OPTICIAN, ST. JOHNS, N.F.” and on the left corner, “ENGLISH.”

This maritime instrument survives in good working order, but with some wear and losses. Features a silver scale calibrated from -5 to +130 degrees and the silver vernier scale reads from 0 to 10 arc seconds in 2 second intervals. The sextant has four shades for the index mirror, and three shades for the horizon mirror (missing one filter glass). The sextant's single scope is housed in its original dovetailed keystone-shaped mahogany box, complete with both hook and eye closures and the original key lock, keep and brass escutcheon. Rosewood handle, index arm clamp, and swing arm magnifier are complete and in working order. A fairly rare sextant both with it’s unique eyeglass frame design and Nova Scotia provenance.

CONDITION: The magnifier swing arm has a single break in the frame, but is all intact and works fine. The brass scope survives with multiple dents in it’s tube. The mahogany box lock and keep are intact, but the locking key is missing. A small piece of wood is missing from one corner of the box top, and a smaller piece missing from the bottom.

 This instrument is housed in a keystone box that is indicative of 18th century construction with fine dovetailed corner joint construction. The box may have been re-used from an earlier sextant or octant, or possibly the sextant is an earlier instrument than we are stating. Research did not find any provenance on Jos. Roper, so the actual date is an estimate.