


Hartridge prism
1984

Replica of Rowland's Diffraction Grating
1905-1915

Diffraction grating with focal power
1973-1983

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

Diffraction Grating on Glass

Two Diffraction Gratings

Circular diffraction grating

Thorpe diffraction grating 14950 lines per inch

Circular diffraction gratings

Ultraviolet grating spectrophotometer

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