Inventory no. 35510 - Former Display Label
English ARTIFICIAL HORIZON
c. 1825
Signed: "Dollond London"
Inscribed: "No. 33 Royal Astronomical Society
Presented by Miss Sheepshanks."
Brass; diameter 68mm; in mahogany box, 100 x 99 x 45mm. The reflecting surface is green opal glass under which is spirits of wine to provide an air bubble when levelling with the three screws. When in use, the heat of the sun expands the alcohol too greatly, so to allow for expansion a screw is removed from a vent and a brass funnel substituted. The printed instructions have been stuck in the lid.
Richard Sheepshanks (1794 - 1855), F.R.S., was Secretary of the Royal Astronomical Society from 1829.
[R.A.S. 59]
R.A.S. Colln.