5 inch Sextant Jesse Ramsden
A miniature sextant by the famous Jesse Ramsden; Miniature Type B reversed VERNIER SEXTANT nr 746 + Box
Type of object:
Sextant
Time period:
Britain rules the waves + France
Place:
London
Date:
1783
Maker / Author:
Jesse Ramsden
Publisher / Printer:
Idem
Dimensions:
17.8 x 19 cm; 5Inch radius
Material:
Brass
Graduation:
0-150°
Inscription:
Ramsden, London Nr 746
Provenance:
The Peter James McSloy Collection
References:
Sextants of Greenwich p 166 en 167
Description
A RARE 5IN. RADIUS MINIATURE BRASS VERNIER SEXTANT BY JESSE RAMSDEN, LONDON, NO. 746, CIRCA 1783-4 with polished-brass one-piece frame, signed on the cross bar 'Ramsden London' and numbered on the back of the index arm '746', sloping arc with scale divided to 130°, Vernier scale with right-aligned '0', fine-screw adjustment with magnifier, back-lever horizon mirror adjustment, quick-release threaded telescope socket, mirrors, shades, telescopes and threaded ebony handle, contained in a fitted keystone box with accessories and trade label for 'Ewer & Sons, Cardiff'
Additional information
Jesse Ramsden FRS (1735 – 1800) was one of the leading manufacturers of scientific instruments in the latter part of the eighteenth century, apprenticed unusually late to the industry at the age of 21, to Mark Burton, mathematical instrument maker in Denmark Street, in the Strand. Ramsden had previously been apprenticed to a cloth worker, although abandoned this trade when he apprenticed himself to Burton in 1756.
Swiftly gaining a reputation, Ramsden began trading under his own name by 1763. It was at this time that he developed a life long association with the Dollond family. Ramsden was undoubtedly influenced by and learnt from John Dollond, who had famously invented and patented 'the achromatic lens'. When Ramsden married Dollond's daughter, Sarah, he subsequently acquired a profitable share in this patent. Opening a shop in Haymarket, near Little Suffolk Street, Ramsden traded under the sign of the Golden Spectacles