Concave Rowland diffraction grating on speculum metal

Made:
1894 in Baltimore and Allegheny City
maker:
Henry Augustus Rowland
Concave Rowland diffraction grating on speculum metal

Creative Commons LicenseThis image is released under a CC BY-NC-SA 4.0 Licence

Buy this image as a print 

Buy

License this image for commercial use at Science and Society Picture Library

License

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 84 x 39 mm, with scratched markings reading 'Plate prepared at the Astronomical / Pysical (sic) Instrument Works of / J A Brashear, Allegheny, PA USA / 1894' and 'Ruled on Rowland's / Engine Johns Hopkins University / Baltimore Md / USA / 1894', in wooden case marked 'V.211.', with '15000 per inch' pencilled inside the base. A paper label on the case marked in German indicates (according to the donor) that the grating came from Paschen's laboratory

Details

Category:
Optics
Object Number:
2000-1440
Materials:
speculum metal and wood
Measurements:
box: 25 x 118 x 118 mm
grating block: 13 x 99 x 101 mm
type:
diffraction grating - reflection
credit:
Imperial College of Science,Technology & Medicine (Spectroscopy Group)