Accession No
2249
Brief Description
Sorby-Browning type micro-spectroscope, by John Browning, English, c. 1875
Origin
England; London; Strand
Maker
Browning, John
Class
optical; chemistry; laboratory apparatus
Earliest Date
1875
Latest Date
1875
Inscription Date
Material
metal (brass, steel); glass
Dimensions
length 223mm; stand height 335mm; length 315mm; breadth 150mm
Special Collection
Provenance
Purchased from Harriet Wynter, 1976.
Inscription
‘John Browning,
London’ (main tube)
Description Notes
Sorby-Browning type micro-spectroscope (aka microspectroscope), by John Browning, English, c. 1875.
Brass. Screw fit draw tube adaptor for microscope with a screw fit lens; brass jaws; screw adjustment of slit width; reflecting prism on arm pivots about a rod moved by external knob; side plate with a second slit, brass jaws and screw adjustment for slit width. Brass mount and steel clips for holding specimen tube; mirror in form mount on ball and socket joint. Rack and pinion focus. Condensing lens and 5 direct vision prisms in draw tube; push fit eye-end with side-mounted illuminating mirror and bright line micrometer; silvered drum head divided 0 - [100], numbered by 10, graduated to 1. Screw fit eye-stop.
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.
The Sorby-Browning type micro spectroscope was designed to facilitate the observation of the absrptive phenomena of the smallest solid or liquid bodies. It contains six small prisms inside the tube.
18/10/2002
Created by: Saffron Clackson on 18/10/2002
FM:40386
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