HENRY DRAPER. 445 



was especially interested in instruments and appliances for Sfientific 

 research. It is said that a visit to Lord Rosse's great reflecting 

 telescope turned his attention especially to solar physics. On his 

 return, he entered Bellevue Hospital as an assistant, and retained 

 the position sixteen months. It was his intention to become a prac- 

 tising physician, but in 1860 he accepted the position of Professor 

 of Physiology in the academic department of the University of New- 

 York. The civil war, which had just begun, called for the services of 

 all trained young men, and he was appointed, in 1862, surgeon of the 

 Twelfth Regiment of New York Volunteers. 



In 186G he was appointed to the chair of Physiology in the Med- 

 ical School, and continued in this position until 1873. The present 

 flourishing condition of the School is said to be largely due to his 

 enthusiasm, to his personal contributions, and to his executive ability. 

 While occupying the chair of Physiology he was engaged in many 

 researches. With a fifteen and a half inch reflecting telescope, con- 

 structed under his supervision, he took photographs of the moon fifty 

 inches in diameter. In 1872 he built with his own hands a reflecting 

 telescope of twenty-eight inches' aperture, and, in August, 1872, first 

 succeeded in jjhotographing a star spectrum, — that of Vega. During 

 the same year he made a photograph of the diffraction spectrum of 

 the sun, extending from the neighborhood of G to O. 



There seem to have been two epochs in his scientific career which 

 are marked by his contributions to science. In the first epoch, from 

 1864 to 1870, he published the following works : — "A Text-Book of 

 Chemistry." " Philosophical Use of Silvered Glass Reflecting Tel- 

 escopes " (Phil. Mag.). " Silvered Glass Telescopes and Celes- 

 tial Photography." " Petroleum, its Importance and its History." 

 "American Contributions to Spectrum Analysis." " Construction of a 

 Silvered Glass Telescope of fifteen and a half inches' Aperture, and 

 its Use in Celestial Photography" (Smithsonian Institution Contribu- 

 tions, Vol. XIV., 1864). 



From 1872, and onward till his death, photography played an im- 

 portant part in all his researches, the second epoch having been 

 prepared for during the first. The following are the principal papers 

 which have been published : — "On the Diffraction Spectrum Photog- 

 raphy" (American Journal of Science, 1872). "Astronomical Ob- 

 servations on the Atmosphere of the Rocky Mountains " (American 

 Journal of Science, 1877). "Spectra of Venus and a Lyra3 in 1877" 

 (American Journal of Science). " Discovery of Oxygen in the Sun 

 by Photography, and a new Theory of the Solar Spectrum." " On 



