Accession No

1267

Brief Description

portable astronomical repeating circle (a.k.a. altazimuth circle), by Cary, English, 1800 (c)

Origin

England; London

Maker

Cary

Class

astronomy; surveying

Earliest Date

1800

Latest Date

1800

Inscription Date

Material

metal (brass); glass; ivory; unknown substance

Dimensions

radius 235mm; overall height 850mm; parts envelope length 220mm; breadth 130mm; height 65mm

Special Collection

Provenance

On loan from St. John’s College, University of Cambridge from 09/1953.

Inscription

‘Cary, London’

Description Notes

Portable astronomical repeating circle (a.k.a. altazimuth circle), by Cary, England, c. 1800, brass.

Circle divided on brass 0 - 90˚ - 0 - 90˚ - 0, graduated to 20´. Telescope with cross hairs, screw-in eyepiece, type-B Vernier on brass, clamp and tangent screw with head divided 0 - 4˚, subdivided to 4´. Telescope mounted in reinforcing brass framework. Circle pivots around horizontal axis, with two counterweights and hanging bubble level beneath. Pillar stand, with divided horizontal circle at base, divided 0 - 180˚ - 0, graduated to 30´, clamp and tangent screws. Tripod base with three levelling screws.

Envelope containing
3 reading microscopes on stands
1 knurled screw
1 object glass cover (end plate detached)
1 drum with pores containing numerous spheres of unknown material
1 unidentified object
Note on envelope in DJB’s hand: ‘Either Troughton or Cary Circle’

Condition good (instrument), fair (accessories - much tarnishing)

Key for this instrument may be on bunch of keys for St. John’s instruments. See location note and notes fields for more information.

References

Events