Spectrum comparator, with travelling micrometer microscope by Adam Hilger Ltd., London, serial No.L1303/22216, dated 1922. Modified for measurement of circular photographic plates and thought to have been used at the University Observatory, Oxford for solar image measurements. Spectrum comparator 1922
Spectrocomparator by Hilger & Watts Ltd, serial nos.L128301 and 61205, on wooden stand with accessories Spectrocomparator by Hilger & Watts Ltd 1961
