Add to albumReflecting circles were used to measure angles necessary for finding longitude. This is a detail of the wooden box for a 'Borda' type brass reflecting circle. The circle was made around 1820, probably by Etienne Lenoir, a scientific instrument maker based in Paris.
The box has three trade labels pasted to the inside of the lid, which reveal some of this particular instrument's history. The uppermost label is that of Lenoir, and gives his address as '340 rue St Honore' which dates the instrument to between 1818 and 1828. The second and third labels belong to provincial instrument makers and probably date from occasions where the instrument was overhauled, at Brest or St. Malo.
The reflecting circle was devised in the 1750s by the German astronomer Tobias Mayer (1723-62). A number of improvements to the instrument were published by the Chevalier de Borda (1733-1799) and gave it its alternative name.
Record details
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- Online ID: 000-180-001-171-C
- Image Rights Holder: National Museums Scotland
- Project:
National Museums Scotland Part 2
Project description View all records in project
- Ref: National Museums Scotland T.1939.1
- Date: Around 1820
- Material: Brass circle / wooden box. Inscription: No. 229
Reflecting circle / telescope / box / accessory
- Dimensions: 11.00" / 6.00" / 12.50" x 12.50" x 3.50"
- What: Reflecting circle / telescope / box / accessory
- Subject: 9. NAVIGATION (Departmental Classification)
22. PHYSICS, Light (Departmental Classification)
- Who: Borda (Eponym)
Lenoir, Paris (Instrument maker)
- Where: EUROPE: France, Paris
- Event:
- Description: Borda reflecting circle, No. 229, by Lenoir, Paris, with brass circle, 6 inch telescope and removable handle, in a wooden box containing a variety of accessories
- References:
- Daumas, M., Scientific Instruments of the 17th and 18th Centuries and their Makers. London: 1972, pp 129, 183-7, 318-9
- Edinburgh Encyclopaedia 1830 Vol VI pp 484-92
- Turner, A. J. From Pleasure and Profit to Science and Security: Etienne Lenoir and the transformation of precision instrument-making in France 1760-1830. Cambridge: 1989, pp 30, 51-60
- Translations:
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