"CELESTIAL PHOTOGRAPHY"

Professor G. W. Ritchey, of the Solar Observatory, of the Carnegie Institution at Mount Wilson, Cal., will deliver an illustrated lecture on "Celestial Photography" in New Lecture Hall this evening at 8 o'clock. The public will be admitted.

Professor Ritchey graduated from the University of Cincinnati in 1887. Between 1896 and 1899 he was superintendent of instrument construction at the Yerkes Observatory. He resigned this position in 1899 to become assistant professor of astronomy at the University of Chicago, where he stayed until 1904. Since January 1, 1909, he has been in charge of the construction of the 100-inch reflecting telescope at the Carnegie Solar Observatory, which is on the top of Mt. Wilson, 6.00 feet above the sea. He cast the famous 60-inch telescopic mirror at the observatory, which is the largest of its kind in the world. Many of the photographs which will be shown this evening were taken with the aid of this mirror.