12 Inch Flat T-Frame Sextant by Jesse Ramsden
Jesse ‘Ramsden London‘ Nr 976 + box
Type of object:
Sextant
Time period:
Britain rules the waves + France
Place:
London
Date:
1790
Maker / Author:
Jesse Ramsden
Publisher / Printer:
idem
Dimensions:
12 Inch or 305 mm radius (40.5 x 43cm.)
Material:
Brass and Mahogany box
Graduation:
- 4 till 125°
Inscription:
Ramsden London
Provenance:
Fr Clemens collection
References:
Harriet Winter Ltd
Mörzer Bruyns Sextants at Greenwich pag 168
Description
A FINE 12 IN. RADIUS FLAT-FRAME VERNIER SEXTANT BY JESSE RAMSDEN, LONDON, CIRCA 1790
apparently unnumbered, with lacquered-brass 'T'-frame, signed on the arc Ramsden London, the scale divided -4°-130°, Vernier with magnifier, braced index arm, adjustable telescope socket, two telescopes, mirrors, six shades, hardwood handle, contained in original fitted mahogany keystone case
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