Glass positive of:- The new planet Pluto. Lowell Observatory 42-inch Reflector. Focal length 220ins. March 5d 3h 44m. C.O. Lampland. 12"x8". (Prepared from silver print [from R.A.S. N.416] lent by Sir James Jeans) Glass positive of the 'new planet Pluto' 1930
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
Positive transparency on film, size 12" x 10", five phases of Venus Lowell Observatory, 1919, (prepared from print purchased from the Lowell Observatory) Positive transparency on film 1919