Sharp-Millar photometer
Date: 1910-1920
Inventory Number: 2006-1-0018
Classification: Photometer
Subject:
Maker: Foote, Pierson & Company (fl. 1897 - 1950)
User: Harvard Engineering School (1918 - 1951)
Cultural Region:
Place of Origin:
Dimensions:
13 × 70.5 × 13.5 cm (5 1/8 × 27 3/4 × 5 5/16 in.)
Description:
This instrument consists of a rectangular wooden box housing an optical system, a moving standard light source and three baffles. The big 90-degree tube outside is where the light to be analyzed enters. There is an eyepiece on the side of the instrument to compare (balance) the intensity of the outside light source to the one inside. The position of the moving standard light inside is shown on the outside scale. Binding posts at one end of the box provides electricity to the light. Top of the box is hinged to allow access to the inner workings of the instrument.
A detailed description of this instrument is found here.
A detailed description of this instrument is found here.
Signedinside: FOOTE, PIERSON & CO.
Inscribedback of instrument, stamped: Property of Harvard Engineering School
FunctionA photometer is used to compare the intensity (brightness) of two light sources. This instrument is aimed at an unknown source of light, which is then compared to the light found inside the instrument. The latter's intensity is varied by moving back and forth inside the instrument. It's position is recorded on the scale outside. It is based on this scale that the intensity of the unknown light source is determined.
For more information on how this particular type of photometer worked, see the following website.
For more information on how this particular type of photometer worked, see the following website.
ProvenanceFrom the Harvard Engineering School.