Accession No

2996

Brief Description

direct-vision spectroscope, 1930 (c)

Origin

Maker

Class

optical

Earliest Date

1930

Latest Date

1930

Inscription Date

Material

metal (brass, alloy, iron); glass

Dimensions

length 110mm; breadth 70mm; height 197mm

Special Collection

Provenance

Donated, 1983. Belonged to G.R. Naylor, Gonville and Caius College, University of Cambridge, Cambridge, England.

Inscription

Description Notes

Direct-vision spectroscope in brass, metal alloy and iron, with black painted finish. Slit; metal alloy jaws; adjustable by a knurled ring; reflecting prism with mirror on pivotted side mount; push focus, screw fit eyestop; horizontal mount; clamp; pillar stand with adjustable height; clamp; side arm; box mount with 2 apertures and glass holder for absorption specimens; cast base.

References

Events

Description
In 1814 Joseph von Fraunhofer noticed that the sun’s spectrum, when dispersed by a glass prism, is crossed by hundreds of fine dark lines. These lines could be used to determine the chemical composition of the sun, stars and many other substances by spectral analysis. The first photograph of the spectrum of a star (Vega) was made by Henry Draper using a spectroscope in 1872.

There are various different forms of spectroscope, but all use a slit and collimator to make a parallel beam of light, a prism for dispersing different wavelengths and a telescope to observe the dispersed spectrum. Direct vision spectroscopes consist of a series of prisms of different refractive indices arranged to produce dispersion of light without deviation.

18/10/2002
Created by: Saffron Clackson on 18/10/2002

FM:44870