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The instrument is mounted on a sturdy metal tripod with a horizontal platform at the top. The instrument consists of an enclosed vertical cylindrical metal chamber which contains a prism. Three narrower cylindrical brass optical components resembling telescopes, including viewing and focusing optics, extend horizontally outwards from the central chamber.

Accession Number: 2012.psy.86

Alternative Name:

Primary Materials: Metal, brass, glass


Damaged manufacturer’s label reads: “Central Scientific Company.”

Dimensions (cm): Height = 31, Width (diameter) = 40


Measures the spectrum of light from an emitting source.


Good. the paint is chipped in some areas. There are scratches over the surface of the instrument

Associated Instruments:

Manufacturer: Central Scientific Company , Chicago

Date of Manufacture: c. 1925


Department of Psychology, University of Toronto

Additional Information and References:

Historical Notes:

Students used this instrument for threshold determinations. In 1915 Edward Bradford Titchener listed a set of tests for determining the extreme limits of the visible spectrum for a particular subject. He described investigations with TR (terminal stimulus, in this case the last detectable spectral line or colour), and LR (Stimulus Limen, or the point at which a stimulus enters consciousness). [Tichener, 1915]

1. Baird, J. W., and R. J. Richardson (1900). A case of abnormal colour sense, with special reference to the space threshold of colours, University of Toronto Studies, Psychological Series, A. Kirschmann (Ed.), Vol. 1. Toronto: Librarian of the University of Toronto.

2. Boring, E. G. (1942). Sensation and Perception in the History of Experimental Psychology. New York: Appleton -Century. p. 155.

3. Titchener, Edward Bradford. 1915. <i>A text-book of psychology.</i> New York: The Macmillan Co.