Circular diffraction grating ruled on glass
- maker:
- W. R. Clark
Circular diffraction grating, 2-inch diameter ruled on glass, 165 lines per mm (4,200 per inch), unsilvered in passe-partout mount, made by W. R. Clark, London, England, 1910 -1915
Circular diffraction grating, 2-inch diameter ruled on glass, 165 lines per mm (4,200 per inch), unsilvered in passe-partout mount, made by W. R. Clark, London, England, 1910 -1915