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Scientific Apparatus
Grating, concave

This grating was ruled on speculum; a light aluminum coat has since been applied. The plate was prepared by the John A. Brashear Co., Allegheny, PA, in 1901. It was ruled on Prof. Henry Rowland's engine at the Johns Hopkins University, Baltimore. Used by Ira Bowen and R. A. Millikan to study the spectral gap between ultraviolet spectra and X-ray spectra. They began their work in Chicago in 1919; work resumed in 1923 in room 1 of E. Bridge at Caltech. The grating was used with a 21' hot spark vacuum spectrometer. Documentation in file. Manufacturer: J. A. Brashear Co., Allegheny, PA.

ID: 1980-00029
Millikan, Robert Andrews, 1868-1953 (Experimental Physicist, Nobel Laureate, Caltech President)

Creation Jan. 1, 1901


Topics: Physics, Spectroscopy

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