Accession No
2946
Brief Description
direct-vision spectroscope, by W. Watson and Sons Ltd., English, 1900 (c)
Origin
England; London
Maker
W. Watson and Sons Ltd.
Class
optical
Earliest Date
1900
Latest Date
1900
Inscription Date
Material
metal (brass, steel); wood; glass
Dimensions
box length 130mm; breadth 67mm; height 36mm
Special Collection
Provenance
Transferred from Physiological Laboratory, University of Cambridge, Cambridge, England, 03/03/1983.
Inscription
‘W. Watson & Sons Ltd.
London.
10614’
‘PHYSIOLOGICAL & LABORATORY
CAMBRIDGE’ (box with ink stamp)
Description Notes
Brass direct-vision spectroscope. Slit with steel jaws, width adjustable by milled ring. Brass barrel with screw-fit eyepiece. Subsidiary brass tube with micrometer scale reflected into field of view, screw adjustment for scale. Slit in screw-fit mount on long draw tube. Covers missing. Fitted wooden box.
cf. no. 2839.
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. 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:44824
Images (Click to view full size):
