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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