Concave Rowland diffraction grating on speculum metal

Made:
1882, Nov 6 in Baltimore and Allegheny City
maker:
Henry Augustus Rowland
and
Henry Augustus Rowland
and
Concave Rowland diffraction grating on speculum metal

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Concave Rowland diffraction grating on speculum metal
Science Museum Group
© The Board of Trustees of the Science Museum

Concave Rowland diffraction grating on speculum metal, grating area 80 x 52 mm, with scratched markings reading 'Ruled on Rowland's machine / Johns Hopkins University Baltimore / 14438 lines to inch / to Capt. Abney / with kind regards / H. A. Rowland, Nov. 6 1882', almost certainly on a plate prepared in J. A. Brashear's works, with remnant of film used for cleaning grating on part of surface.

Details

Category:
Optics
Object Number:
2000-1448
Materials:
speculum metal
Measurements:
overall: 14 x 102 x 100 mm
type:
diffraction grating - reflection
credit:
Imperial College of Science,Technology & Medicine (Spectroscopy Group)