40 inch telescope. Eyepiece of the 40 inch refractor telescope at the University of Chicago's, Yerkes Observatory, Williams Bay, Wisconsin, USA. The observatory was founded in 1897 by George Hale with a grant from businessman Charles Yerkes. It has been used by many eminent scientists of the 20th century, including Chandrasekhar who conducted his research on black holes there, which led to his Nobel Prize in physics.