Accession No
3104
Brief Description
compound prism 1875-1900
Origin
Maker
Class
optical
Earliest Date
1875
Latest Date
1900
Inscription Date
Material
glass
Dimensions
length 114mm; breadth 112mm; height 90mm
Special Collection
Provenance
Transferred from Institute of Astronomy, University of Cambridge, Cambridge, England, 12/1983.
Inscription
Description Notes
Compound of 3 prisms comprising two 30˚ and one 90˚ to form the half prism and the reflecting end prism of a train; non-optical surfaces black.
Condition
References
Events
Description
Prism
A prism consists of a translucent piece of glass or crystal, usually triangular in cross section, which is used to separate light into a spectrum of its separate colours.
The instrument works because different wavelengths of light are refracted (bent) by different amounts as they enter and leave the prism; the shorter wavelengths (towards the blue end of the spectrum) are refracted by the greatest amount, and the longer wavelengths (towards the red end) are refracted the least. This spreads out normal white light, which is a mixture of all the different colours, into its constituent parts and produces the rainbow effect of a spectrum.
18/10/2002
Created by: Saffron Clackson on 18/10/2002
FM:43415
Images (Click to view full size):
