Accession No
1872
Brief Description
prism, early 18th C
Origin
Maker
Class
optical
Earliest Date
1700
Latest Date
1730
Inscription Date
Material
glass
Dimensions
length 187mm; breadth 29mm; depth 25mm
Special Collection
Provenance
Purchased from Peter Delehar, 146 Portobello Road, London in 31/10/1973.
Inscription
Description Notes
Glass 60˚ prism with two glass handles. Prism noticeably misshapen.
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:43377
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