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, 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
- credit:
- Imperial College of Science,Technology & Medicine (Spectroscopy Group)