Accession No
3433
Brief Description
polariser, by J. Duboscq, French, 19th Century
Origin
France; Paris
Maker
Duboscq, J.
Class
optical
Earliest Date
1840
Latest Date
1900
Inscription Date
Material
metal (brass, oxidised brass); glass
Dimensions
height 70mm; diameter 65mm
Special Collection
Provenance
Purchased from Department of Physics, King’s College, London, England, 10/1986. Purchased with the assistance of a grant from PRISM Fund.
Inscription
‘J.DUBOSCQ
PARIS’ (top)
Description Notes
4 circular oxidised brass plates, each pair holding a parallelepiped prism and joined by 4 brass columns, screwed into plates. The two pairs joined by 3 short brass columns. Windows for viewing at ends of prisms.
Condition fair (tarnished, one plate bent); complete
References
Events
Description
This object is made of two prisms held together by a metal frame. These prisms are held at the exact angle at which light would refract. This means that even though the prism are at an angle and there is no direct line of site to the through the polariser, because the light refracts when it enters the glass, you can see right through the polariser. This is a very good example of the phenomenon. The main use for a polariser is in magic tricks. The polariser effectively makes the light bend round corners, the effect is that the audience thinks that they can see that a box is empty but in fact there is a rabbit inside.
Created by: Richard
FM:39465
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