Accession No
1553
Brief Description
double refracting prism, 19th or 20th C
Origin
Maker
Class
optical
Earliest Date
1800
Latest Date
1950
Inscription Date
Material
stone (Iceland Spar or calcite)
Dimensions
length 52mm; breadth 30mm; depth 22mm
Special Collection
Provenance
Inscription
Description Notes
double refracting prism, Iceland Spar; 6-sided crystal.
Condition fair (chipped); complete
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:40405
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