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Description: | Plane Rowland diffraction grating on speculum metal, grating area 45 x 35 mm, with scratched markings reading 'Plate prepared at the Astronom / ical and Physical Instrument / Works of J A Brashear / Allegheny Pa USA', 'Ruled on Rowlands Engine / Johns Hopkins Univty / Baltimore Md / USA', 'AE... / 1896' and '14438 lines to one inch / 568 to one m/m', in blackened metal stand with removable glass cover and three adjustable feet. | License: | http://creativecommons.org/licenses/by-nc-sa/2.5/ | Subjects: | diffraction grating - reflection | Temporal: | 1895-1909 (estimated) | Source: | Science Museum | Creator: | Rowland, H. A., Professor | Identifier: | 2000-1444 | Go to resource |
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