Sharp-Millar photometer
Date1910-1920
Inventory Number2006-1-0018
ClassificationPhotometer
Subject
Maker
Foote, Pierson & Company
fl. 1897 - 1950
User
Harvard Engineering School
1918 - 1951
Cultural Region
Place of Origin
Dimensions13 × 70.5 × 13.5 cm (5 1/8 × 27 3/4 × 5 5/16 in.)
Material
DescriptionThis 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.
Hermann & Pfister
Date: circa 1872
Accessories: pine box; instruction manual; glass tubes (2); open-ended tube; gas lamp (DW0854b)
Object number: DW0854a
Kollmorgen Corporation
Date: circa 1980
Accessories: Two instructions manuals: SPECTRA PRITCHARD PHOTOMETER, MODEL 1980A, CONDENSED OPERATING INSTRUCTIONS; INSTRUCTION AND MAINTENANCE MANUAL FOR SPECTRA PRITCHARD PHOTOMETER, Model 1980A. Both in gray archival box, C2-H1
Object number: 2004-1-0214a
Nachet et Fils (I)
Date: 1862-1872
Accessories: 3 Objectives; 2 oculars; substage mirror with mounting screw lost; 1 prepared slide
Object number: 1030
