Sextant

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This brass sextant was made around 1790, probably by Jesse Ramsden (1735-1800), a scientific instrument maker based in London. The design for this type of sextant was patented in 1788 by Edward Troughton, another London-based scientific instrument maker.

The 'pillar frame' sextant with silver scale has two thin frames of plate brass held together by a series of brass pillars. The design was previously popular in the navy, and this instrument is engraved on the upper bridging joint 'Capt Wood', for a one-time owner.

This effort - to combine lightness and rigidity in the sextant frame - was patented by one of Ramsden's competitors, Edward Troughton. According to a contemporary in 1828, these were 'in great request in the naval service'.

Record details

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• Online ID: 000-100-104-228-C
• Image Rights Holder: National Museums Scotland
• Project: National Museums Scotland
  Project description   View all records in project
• Ref: National Museums Scotland  T.1963.42
• Date: Around 1790
  c. 1790
  
• Material: Brass
  
• Dimensions:
• What:
• Subject:
• Who: Horsburgh Collection
  Ramsden, London (Instrument maker)
  
• Where: England, London
  
• Event:
• Description: Brass sextant with the hand lens missing, by Ramsden of London, c. 1790
  
• References:
  • For Ramsden and Troughton, see Clifton, Gloria, Directory of British Scientific Instrument Makers 1550-1851. London: 1995, pp 227-8 
  • Turner, Anthony, Early Scientific Instruments 1400-1800. London: 1987, pp 228-9; Bennett, J.A. The Divided Circle: A history of instruments for astronomy, navigation and surveying. Oxford: 1987. pp 136-8 
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