Photograph showing Titanum Oxide spectrum, compared with the banded Spectrum of the Third type stars, as represented by Omicron Ceti in glazed frame. I. Spectrum Omicron Ceti ( Slipher), II. Spectrum of TI Oxide (Fowler). Photograph showing Titanum Oxide spectrum 1911
Glass positive:- Halley's comet, V.M.Slipher, Lowell Observatory 1910, May 7, Exposure 24 min, 6 1/2" x 8 1/2" Glass positive:- Halley's comet 1910