2.5 x 2.5 inch, 31° carbonic disulphide liquid prism
Date: circa 1875
Inventory Number: 2007-1-0029
Classification: Prism
Subject:
Maker: Alvan Clark and Sons ? (1846 - 1958)
User: Oak Ridge Station (1931 - 2005)
User: George R. Agassiz Station, Harvard (1951 - 1982)
User: Harvard College Observatory (founded 1839)
Cultural Region:
Place of Origin:
Dimensions:
8.8 x 9.7 x 5.3 cm (3 7/16 x 3 13/16 x 2 1/16 in.)
Material:
Description:
A prism with angles of 13° - 37°- 130° is encased into a prism-shaped glass container. The container is 82°- 82° - 16°. It is made of optical quality plate glass glued together and has a hole on one side for filling it with a liquid.
The liquid prism formed by the combination has angles of approximately 31°- 67°- 82°. The working face of the interior liquid prism is about 6.5 x 6.5 cm.
The liquid was likely carbonic disulphide, and is no longer present.
The liquid prism formed by the combination has angles of approximately 31°- 67°- 82°. The working face of the interior liquid prism is about 6.5 x 6.5 cm.
The liquid was likely carbonic disulphide, and is no longer present.
Signedunsigned
FunctionThis hollow prism was filled with a solution of carbonic disulphide, which gave a large dispersion of light passing through it. The stuff reputedly smelled awful and had a temperature-sensitive index of refraction, but this type of prism was less expensive than one of solid optical glass. The prism was used for spectroscopy.
Historical AttributesIn the 1860s and 1870s, the firm of Alvan Clark and Sons made quite a few carbonic disulphide prisms and spectroscopes for the Harvard physics and chemistry departments. They also made spectroscopes for the Harvard College Observatory, and may have made this example.
Curatorial RemarksPrimary sources refer to the prisms as being filled with carbonic disulphide, but modern references call these carbon bisulphide.
ProvenanceHarvard College Observatory; George R. Agassiz Station; transferred to CHSI in 1969.