10 Inch Flat Vernier Sextant Jesse Ramsden
Vernier Sextant by Ramsden London nr. 1093 + Box
Type of object:
Sextant
Time period:
Britain rules the waves + France
Place:
London
Date:
1791
Maker / Author:
Jesse Ramsden
Publisher / Printer:
idem
Dimensions:
31.7 x 31 cm, or 10 inch radius
Material:
Brass and glass
Graduation:
0- 135°
Inscription:
Ramsden London, nr 1093 behind the apex
Provenance:
via F. Clemens and E. Delbon, from the Peter James McSloy collection
References:
Sextants of Greenwich pag 172 nr 149
Description
Important brass sextant by probably the most important sextantmaker in the 18th century, Jesse Ramsden
Signed on the arc Ramsden London and numbered behind apex’ 1093’; scale divided to 135°, adjustable telescope socket, seven shades, Index and Horizon mirrors, rosewood handle. No box
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