 000-100-044-570-C © National Museums Scotland |
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Theodolite
A theodolite is a surveying instrument for measuring horizontal and vertical angles. This brass example was made around 1750, and retailed by London optician Benjamin Martin (1704/5-1782).
This instrument consists of a compass, with two spirit levels, and has both fixed and movable sighting vanes on a graduated circle. It could be used if attached to a ball-and-socket levelling head and tripod (neither shown here), to take readings in both vertical and horizontal planes.
Martin was a much respected designer of scientific instruments and had a shop at the sign of 'Hadley's Quadrant and Visual Glasses' in Fleet Street in London. He was also a prolific writer and gave lectures on Natural Philosophy illustrated with his instruments.
Record details
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Online ID: |
000-100-044-570-C |
Image Rights Holder: |
National Museums Scotland |
Project: |
0098: National Museums Scotland
Project description | View all records in project |
Ref: |
National Museums Scotland T.1971.87 |
Date: |
Around 1750
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Material: |
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What: |
Circumferentor / compass
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Subject: |
5. CARTOGRAPHY, Surveying (Departmental Classification)
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Who: |
B. Martin, London (Maker)
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Where: |
England, London
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Event: |
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Description: |
Circumferentor and compass by B. Martin of London
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References: |
- For an explanation of the evolution of the theodolite, see Bennett, J.A. The Divided Circle: A history of instruments for astronomy, navigation and surveying. Oxford: 1987. pp 145-9
- Millburn, John R., Benjamin Martin author, instrument-maker, and country showman. Leyden: 1976, pp 224-5
- Millburn, John R., Retailer of the sciences: Benjamin Martin's scientific instrument catalogues, 1756-1782. London: 1986, p 24
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