Painted black rectangular box with open sides. Detachable top with viewer/eye piece. Metal rod protruding from rectangle. Interior consists of two separate mirrored chambers separated by a paper covering with three oblong-shaped grease stain.
Accession Number: 2011.ph.466
Primary Materials: Painted metal, glass mirror, paper.
Height = 27 cm, Width = 22 cm, Length = 13 cm
This instrument is used to visually compare the luminosity of two light sources. By looking through the hole the user can see, by means of the mirrors, the paper containing a grease spot from opposite sides. Placing a light source on one side of the instrument illuminates the paper and its grease spot. By placing the photometer between two light sources and comparing the relative brightness of the grease spots, the viewer can judge the relative luminosity of the two sources.
Very subtle flakes and scratches from wear on painted metal.
Date of Manufacture:
Acquired from Physics department, University of Toronto.
Additional Information and References: