|
Date: |
|
Description: | LO.55. (Lecture demonstration apparatus catalogue number in aluminium paint). NAT PHIL LO 55, NP 593 (on white preprinted label {ex Hunterian Museum} removed). Signed E. LUTZ, PARIS MANU LUTZ,E[douard] circa 1875 [49, Roue St-Germaine], Paris France The prism and lens can both rotate through 360 degrees. The prism which had been missing since 1957 was found with the contents of LO.42.
When light is passed through a cylindrical lens the lens can only form images of lines parallel to the axes of its surface. So if for example a cross hair was viewed through a cylindrical lens only one of the hairs would form a sharp image, the other would be invisible
As light enters a prism it is refracted or bent as it passes from the air into the glass. Refraction causes the different wavelengths to separate or disperse. The light travels on through the prism and is reflected internally until it re-emerges from the prism. As the light passes from the glass into the air it disperses even more. This gives rise to a wide band of colours that range from red through orange yellow, green, blue, indigo and violet.
By moving the glass prism so that light passing through a slit is dipersed by the prism and transmitted to the lens at right angles to its vertical axis then only a small portion of the visible spectrum, in the form of a pencil beam, will emerge from the lens.
On loan to the Physics and Astronomy Department EXIT NUMBER 2092 it is object 4 in display case A Kelvin & 'The New Professors', in room 470, The Kelvin Building, Department of Physics and Astronomy Glasgow University. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
|
|