This very fine and highly polished small sextant was made by John Sewill of Liverpool. Instruments by this maker are rare, but several of his marine chronometers also survive. The instrument features a lattice frame in brass with silvered scale, vernier, magnifier, three telescopes, two sets of filters, mirrors and a rosewood handgrip. Its mahogany and brass case bears a plaque, "Sewill, Liverpool, Maker to the Royal Navy" The sextant itself also has the maker’s mark on the scale and is numbered 3893.

The box measures 10 x 9 x 5 inches. Arc is 9 inches wide. The box also includes the original retailer’s label, "John Parkes and Sons, Marine Opticians, Liverpool"

This instrument was part of a 1987 exhibition at the Pacific Asia Museum entitled "Trade and Treasure. Repercussions of the China Trade and its Impact on Maritime Technology."