Accession No

2756

Brief Description

reflecting telescope, 24"/5" Gregorian, by James Short, English, 1768 (c)

Origin

England; London

Maker

Short, James

Class

astronomy; optical

Earliest Date

1768

Latest Date

1768

Inscription Date

Material

metal; brass; glass; ivory

Dimensions

length of barrel 844mm; diameter of barrel 124mm

Special Collection

Provenance

On loan from Christ’s College, University of Cambridge, Cambridge, England since 02/07/1981.

Inscription

James Short London 69-24 (eyepiece end of barrel)

Description Notes

Reflecting telescope, 24"/5" Gregorian; by James Short, English, circa 1768.

Brass Gregorian reflecting telescope. 24-inch focal length; 5-inch aperture. 844mm-long barrel with cover (not readily removed). Mirror cell (not readily removed) secures speculum metal primary mirror (d: 124mm). Screw-in two-lens eyepiece with screw-on pinhole eyestop. Focus by long screw with knurled and moving secondary mirror. 4 screws secure barrel to open brass semicircle, on altazimuth mount with two slow motions moved by screws with square ivory handles. Knurled screw disengages vertical control. Telescope rotates around pillar stand with clamping screw. Folding tripod base with cabriole feet.
Screw holes on barrel for finder (missing).

Fitted wooden box (lid was broken has been conserved) with screw-in cover for mirror cell when eyepiece removed, and alternative secondary mirror in fitted tin box.

Condition good.

References

Events