Accession Number: 2009.ph.14
A flat metal disc, one side of which is reflective, with a rectangular grating in the middle. This is contained within a wooden box which shows evidence of having been screwed shut. There is a paper label affixed to the top of the box.
Primary Materials: Metal, Glass
The box has a label which reads: “TO WHOM IT MAY CONCERN: This box contains one diffraction grating which is being sent to Dr. E.F. Burton by Dr. H.G. Gale for trial purposes,” (typewritten); This side up (handwritten, red pencil); 317.5 Centimeter ______” [label torn]; on one edge of the grating is written “TOP”; on the back of the grating is engraved “Grating No. 129” and “Melt No. 151”.
Dimensions (cm): Height = 2, Diameter = 14.5
Diffraction gratings break light into a spectrum.
Fair: The box had been screwed shut, perhaps for transport. Now, only a few screws remain in place; they are rusty. The paper label on the lid is ripped in one corner. The reflective side of the disc is somewhat dulled and corroded; this is especially true of the rectangular grating, which is browned, although it still reflects and splits light with a prism-like effect.
Date of Manufacture: 1930-1940
Sent to Dr. E.F. Burton (University of Toronto Department of Physics) by Dr. Henry Gordon Gale at Department of Physics at the University of Chicago.