Accession No

1079

Brief Description

brass reflecting circle, by Edward Troughton, English, 1810 (c)

Origin

England; London; 133 Fleet Street; The Orrery

Maker

Troughton, Edward

Class

navigation

Earliest Date

1810

Latest Date

1810

Inscription Date

Material

metal; glass; brass; wood; gold

Dimensions

radius 132mm; height 450mm mercury bottole height 122mm; base diameter 76mm; artificial horizon length 167mm; breadth 91mm; height 113mm

Special Collection

Provenance

On loan from St. John’s College, University of Cambridge from 08/1951.

Inscription

Troughton 218 London

Description Notes

Brass reflecting circle with mahogany handles and gold scale. Brass pillar stand with counter weights and three radial feet with levelling screws. Circle mounted on the stand by means of an axle. Circle itself has a lattice frame, adjustable index mirror, telescope sights and a horizon glass. Two sets of three filters. Two wooden handles, one with screw-in section so that instrument may be mounted on stand from either side. Three index arms each with mounting for reading microscope (missing), one with clamp and tangent screws; all have type-B verniers. These move over the gold degree circle which is divided to 720˚, graduated to 20´, and part is numbered 140˚ - 0 - 140˚ by 10˚.

Artificial horizon with wooden tray.
Wooden mercury bottle [empty] with brass cap.

good condition

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