Rowland Diffraction Grating

Description
This concave metal grating probably belonged to Samuel Pierpont Langley, director of the Allegheny Observatory and professor of astronomy at the Western University of Pennsylvania (now the University of Pittsburgh). It probably came to Washington in 1887 when Langley became the third Secretary of the Smithsonian Institution.
It is marked "plate polished and corrected by J. A. Brashear Pittsburgh, Mar. 1886 Radius 64 Ruled by Schneider on Rowland engine Johns Hopkins University April 1886 - lines to in temp-".
Location
Currently not on view
Object Name
diffraction grating
date made
1886
maker
Rowland, Henry A.
Brashear, John A.
Measurements
overall: 4 3/4 in x 6 3/4 in x 7 3/4 in; 12.065 cm x 17.145 cm x 19.685 cm
place made
United States: Maryland, Baltimore
ID Number
PH*316718
catalog number
316718
accession number
227592
subject
Science & Mathematics
See more items in
Medicine and Science: Physical Sciences
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Smithsonian Astrophysical Observatory

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