Catalogue Page from Exhibition Catalogue: 1909 Fifty-fourth Annual Exhibition of the Royal Photographic Society of Great Britain

showing (E09A061) Exhibit no. [812]: New Model Portable Concave Grating Spectroscopic Camera, with repeating back taking six spectra upon a ¼-plate, giving very fine detail, quick exposure and extreme facility in use. by Sanger-Shepherd & Co. ()