Accession No

1610

Brief Description

transit instrument, portable, by Dollond, English, 1800 (c)

Origin

England; London; St. Paul’s Churchyard

Maker

Dollond

Class

astronomy

Earliest Date

1800

Latest Date

1800

Inscription Date

Material

metal (brass); glass; wood

Dimensions

height to top of circle 440mm; telescope length (min) 564mm; d vertical circle 146mm; diameter base 304mm box length 470mm; breadth 455mm; height 196mm

Special Collection

Provenance

On loan from Trinity Hall, University of Cambridge from 16/03/1972.

Inscription

Dollond London (degree scale)

Description Notes

Brass transit instrument, portable, by Dollond, English, c. 1800.

Braced brass ring forms base with double A-frame stand secured to it by six knurled screws. Three levelling screws. One A-frame carries turned wooden platform for lamp for illuminating cross-wires through horizontal axis. Y bearings adjustable on both sides in different dimensions.
Set in the bearings is an axis carrying a vertical circle at one end and supporting the telescope. Telescope with achromatic object glass in screw-fit brass cell, push-fit right angle eyepiece, focus by knurled screw moving object glass by rack and pinion. Vertical circle divided anticlockwise 0 - 90˚, [0] - [90˚], 0 - 90˚, [0] - [90˚], numbered by 10˚, graduated to 30´. Two type-B verniers on index arms moving over the scale.

Condition - good.

References

Events