452 stereoscopic pairs of cloud chamber photographs and five single photographs of electric discharges (all glass negatives) Cloud chamber photographs, 1922 1922
Scientific stereoscope for use on desk or bench top by Carl Zeiss Jena, Nr. 5284, and 14 (plus one duplicate) out of a set of 20 stereographs, post-1908 Scientific stereoscope for use on desk or bench top by Carl Zeiss Jena 1908-1914 (estimated)
Photographic replica plane diffraction grating, area 27 x 27 mm, on glass plate, wrapped in a piece of paper marked in manuscript 'Photograph copy of / Spectrum Grating / 6000 lines per inch / Dr. . . . 's / Keep dry & do not rub / the film side'. [The three letters of the name are indecipherable.] Photographic replica plane diffraction grating 1900-1949 (estimated)
Photographic replica plane diffraction grating, area 19 x 12 mm, on glass plate, wrapped in an envelope marked in manuscript 'Gratin (Replica) / made by photographing in much / reduced size a grating of lines / ruled in India ink on paper / by Mr. Barrow / I.C.Sc.T'. Very coarse line spacing. Photographic replica plane diffraction grating 1907-1949 (estimated)