Accession No
1211
Brief Description
portable direct-vision spectroscope, by John Browning, English, 1870 (c)
Origin
England; London; 63 Strand
Maker
Browning, John
Class
optical
Earliest Date
1870
Latest Date
1870
Inscription Date
Material
metal (brass); glass
Dimensions
minimum length 147mm
Special Collection
Provenance
Donated by the Science Museum, London.
Inscription
John Browning
63 Strand London (one side of tube)
Grace’s
Spectroscope (other side of tube)
Description Notes
Portable direct-vision spectroscope, by John Browning, English, c. 1870.
Brass direct-vision spectroscope. Slit, with glazed cover, adjustable by milled ring. Eyepiece moved for focussing by external rod attached to milled screw.
Cloth lined leather case.
Very good condition.
References
Events
Description
Spectroscope
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:40369
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