Accession No

2121

Brief Description

Borda-type repeating reflecting circle, Secretan, France, c. 1860

Origin

Paris; France

Maker

Secretan

Class

navigation; astronomy

Earliest Date

1860

Latest Date

1860

Inscription Date

Material

metal (brass, oxidised brass, silver); glass; wood

Dimensions

box length 334mm; breadth 327mm; height 129mm

Special Collection

Provenance

Transferred from Institute of Astronomy, University of Cambridge, Cambridge, England, 10/1975.

Inscription

‘Secretan a Paris’

Description Notes

Borda-type repeating reflecting circle, Secretan, France, c. 1860, brass and oxidised brass.

Adjustable index mirror. Brass index arm with reading microscope on jointed subsidiary arm, type-B vernier on silver, hinged opaque shade for reading vernier, clamp and tangent screws. Oxidised brass arm carrying horizon glass, two separate shades (one for index mirror), silver type-B vernier, telescope, clamp and tangent screws, inner brass scale divided by degrees 180 - 0, 0 - 180, with two brass cursors. Distance between circle and telescope adjustable by knurled screw, with scale divided 5-0-5. Silver outer 720˚ scale divided by degrees, subdivided to 20’ and numbered 00-710 by 10˚. Limb supported by radiating spokes. Reverse has screw thread for handle (missing). Fitted wooden box contains 2 telescopes, 9 shades, 2 eyepiece shades, reading glass, adjusting square, wood and brass handle, screwdriver (wooden handle), 2 brass pieces, brass piece with aperture.

Condition: good.

References

Events