Accession No
2098
Brief Description
diffraction graint by Rayleigh, c.1870
Origin
Maker
Rayleigh
Class
optical
Earliest Date
1870
Latest Date
Inscription Date
Material
glass
Dimensions
length 60mm; breadth 49mm box length 92mm; breadth 92mm; height 25mm
Special Collection
Provenance
Donated by widow of C.M. Sleeman, 1975. Property of C M Sleeman (1883-1973?), Fellow of Queens’ College, Cambridge
Inscription
‘F.A. Nobert fecit…Barth Pommeraniae’ (ruling)
‘6000’ (ruling)
‘Diffraction Grating 6000 to 1 inch. From a Nobert’s grating; photographed by & given to P R S by Lord Rayleigh’ (MS note in box)
Description Notes
Photo-replica of a Nobert 6000/inch ruling in glass mount.
Condition
References
Events
Description
Diffraction grating
Grimaldi (an Italian physicist) saw that the edges of shadows are not completely sharp, but have fringes. Only later, in 1785, when multiple edges were placed next to one another to form a grating, was the full importance of this observation elucidated.
A diffraction grating consists of very closely spaced lines on a reflecting surface (the line ruling process must be very precise). The lines disperse light into component wavelengths (much like a prism does) and this is useful for precise determination of the magnitude of wavelengths.
18/10/2002
Created by: Saffron Clackson on 18/10/2002
FM:43457
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