Replica plane diffraction grating, usable area 64 x 64 mm, mounted on a glass lantern slide, with glass cover plated and taped edges, with label reading 'Ives' Photographic Replica of Diffraction Grating / C153, $1.50. Nearly 3,000 lines to the inch. / Sold by the Scientific Shop, Chicago.' Label annotated in red ink '2,888'.