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
Glass positive:- Halley's comet and Venus, H.E. Wood Union Observatory, Johannesburg, 1910, May 6, 10-inch Cooke lens, focal length, 45in exposure, 60 min, 6 1/2" x 8 1/2" Glass positive:- Halley's comet and Venus 1910
