Accession No

1207

Brief Description

heliostat, by J. Duboscq, French, 1860 (c)

Origin

France; Paris

Maker

Duboscq, J.

Class

astronomy; optical

Earliest Date

1860

Latest Date

1860

Inscription Date

Material

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

Dimensions

box height 565mm; breadth 430mm; depth 405mm

Special Collection

Provenance

Transferred form the Department of Mineralogy and Petrology, University of Cambridge.

Inscription

‘J. Duboscq a Paris’
‘No. 128’

Description Notes

Large Silbermann heliostat, brass. Circular base rotates on flat tripod stand with 3 levelling screws, with clamping screw and short setting scale. Bubble level divided 20-0-20 by 1. Two brass uprights support horizontal axis with setting quadrant divided on brass -5-110 by 1˚ subdivided to 30’ with vernier. Brass-cased clockwork movement hanging beneath axis with 2 silvered dials and blued steel hands, knurled knob and pointer for selecting ‘M’ or ‘A’ and rate adjustment. Above axis is mount for silvered glass mirror with 2 setting arcs and one divided circle. One arc undivided moved by rack and pinion by knurled knob. The other divided for declination 30-0-30 by 1o, subdivided to 30’, with vernier. Date scale on reverse. Clamping screw and brass setting key fitting onto square. Pinhole and target cross mounted on declination scale, for setting by sun. Fitted wooden box and brass winding key, mirror cover, brass setting key and small box containing “Screws belonging to Mirror”.

References

Events