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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