John W. Draper's Position in Science

Abstract

IN NATURE of Sept. 24 the interesting Calendar of Discovery and Invention states that the first astronomical photographs were made in 1840 by John W. Draper, using daguerreotype plates; also that Draper's last great photographic achievement was a record of the nebula in Orion, made on Sept. 30, 1880, and that attempts at improving on this first effort were cut short by Draper's death. Here, at New York University, where Draper was a member of the faculty during the productive years of his life, we were gratified to see this appreciative note about him. In the interest of accuracy, however, it should be stated that the photographs of the great nebula in Orion were obtained by Draper's son, Henry, who was in his own right the leader of stellar photography in America. The photograph made on Sept. 30, 1880, was given 57 minutes of exposure. In March 1881 a better photograph was made by Henry Draper from an exposure of 104 minutes, and on Mar. 14, 1882 (more than two months after the death of John W. Draper), a remarkably successful exposure of 137 minutes was made, which showed stars of the 14.7 magnitude of Pogson's scale—stars invisible to the eye. Henry Draper also obtained many excellent photographs of the spectrum of the nebula in Orion. Unfortunately, Henry Draper died suddenly on Nov. 20 of the same year at the age of forty-five.