Problems of Celestial Photography

Professor G. W. Ritchey, of the Solar Observatory of the Carnegie Institution at Mount Wilson, Cal., delivered an illustrated lecture on "Celestial Photography" in New Lecture Hall last evening.

Remarkable progress has been made in the last few years in the construction of telescopes and especially in the construction of those instruments made for photographing celestial bodies. This progress seems all the more wonderful when one considers the very great problems to be solved. One of the most difficult of these problems is that of contending against the varying atmospheric conditions, but the modern instruments are so skillfully constructed that photographs of marvelous clearness have been obtained in spite of the varying density and light of the air strata.