Thomas Jones box sextant c 1840
Box sextant which is signed on the upper plate:thomas jones, 62 charing cross, london, a lacquered brass box sextant, signed above the silvered scale, with vernier and magnifier, with screw cover. The instrument has an inlaid silver scale from -2Ã‚Â° to 134Ã‚Â° by 30 arcminutes, measuring to 125Ã‚Â° (the digits are read from the pivot). The sextant has a silver vernier measuring to 1 arcminute, with zero at the left. 7cm diameter, in a morocco red leather covered crimson velvet lined case.
Look for reference in: sextants at greenwich, w.F.J. Morzer bruyns on page 190.