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Physical Sciences Collection - Surveying and Geodesy

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Repeating Circle - click to enlarge

Repeating Circle - click to enlarge

Click photos to enlarge.

Repeating Circle

Catalogue number:
PH*317690

Inscriptions:
"Chollet Delamarre Constructeur Rue de Fourcy St Antoine 6 Paris."

Dimensions:
horizontal circle 8 inches diameter; lower telescope 14 inches long

Discussion:
The horizontal circle of this instrument is graduated to 2 minutes, and read by opposite verniers to 2 seconds; the vertical arc is graduated to 20 minutes, and read by vernier to 3 seconds. There are two telescopes: an upper one (which is missing), and a lower one which is attached to the central pillar, below the horizontal circle. Delamarre worked in Paris in the first half of the 19th century, making repeating circles, graphometers, etc.

Ref: Deleuil, Catalogue des Instruments de Physique, de Chimie, d'Optique et de Mathématiques (Paris, 1863), p. 69.

Further Information:

Repeating Circle

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