Diffraction Grating


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.

The inscription reads "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-".

Date Made: 1886

Maker: Rowland, Henry A.Brashear, John A.

Location: Currently not on view

Place Made: United States: Maryland, Baltimore

See more items in: Medicine and Science: Physical Sciences, Science & Mathematics


Exhibition Location:

Credit Line: Smithsonian Astrophysical Observatory

Data Source: National Museum of American History

Id Number: PH.316718Catalog Number: 316718Accession Number: 227592

Object Name: diffraction grating

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 cmoverall: 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

Guid: http://n2t.net/ark:/65665/ng49ca746aa-39d3-704b-e053-15f76fa0b4fa

Record Id: nmah_1184621

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