120° prism half-polished
Datecirca 1900
Inventory Number2007-1-0427
ClassificationPrism
Subject
Maker
American
?
Owner
Theodore Lyman IV
?
1874 - 1954
User
Harvard College
founded 1636
Cultural Region
Dimensions2.2 × 8.9 × 6 cm (7/8 × 3 1/2 × 2 3/8 in.)
Material
DescriptionGlass prism with angles 30°, 30°, 120°. One short face and the long face are polished. The other short face and top are frosted glass. There is evidence of adhesive on the long face where a rectangular mask had been placed. The mask is no longer present.
The pencil annotation on the top face--T. L. L--may refer to Theodore Lyman's lab.
The pencil annotation on the top face--T. L. L--may refer to Theodore Lyman's lab.
Signedunsigned
Inscribedin pencil script on top: T. L. L
in orange paint: H
FunctionThis prism is used like a right angle prism to divert light by means of internal reflection on the longest face. Light rays would be diverted by 120°.
ProvenanceLikely from Theodore Lyman's lab; later used in the Harvard College Optics Lab, and transferred to CHSI in 1967.
Historical AttributesLikely used by Theodore Lyman.
American
Date: circa 1914
Accessories: mounting plates and pads
Object number: 1998-1-1389
American
Date: 1900-1925
Accessories: none
Object number: 1998-1-1398b
