


Hartridge prism
1984

Diffraction grating with focal power
1973-1983

Pair of glass crossed diffraction gratings in single mount
1900-1956

Replica of Rowland's Diffraction Grating
1905-1915

Thorpe diffraction grating 14950 lines per inch

Circular diffraction gratings

Circular diffraction grating

Diffraction Grating on Glass

Ultraviolet grating spectrophotometer

Two Diffraction Gratings

Diffraction Grating
1910-1915
Diffraction grating
1963
Diffraction grating 1800 gr/mm on 6 inch diameter blank
Diffraction ruling on glass sheet
Thorpe's Transparent Relica of Rowland's Diffraction grating
Perkin-Elmer 257 IR grating spectrometer.
circa 1980
Ebert grating spectrograph E543 by Hilger & Watts Ltd.
1967-1968
selection of 8 sets of diffraction rulings on polished steel
1820-1829