Yerkes Observatory 01 by Todd Smith

Canon S5 IS

From the Wikipedia entry:

The Yerkes Observatory, arguably the birthplace of modern astrophysics, is an astronomical observatory of the University of Chicago in Williams Bay, Wisconsin. It was created in 1897 by George Ellery Hale and financed by Charles T. Yerkes. The observatory represented a shift in the thinking of observatories, from mere housing for a telescope and observer, to the modern concept of observation equipment integrated with laboratory space for physics and chemistry. A 102 cm (40 inch) refracting telescope built by the master optician Alvan Clark is located inside. It remains the largest refracting telescope ever used.