University of Chicago
Telescopes at Yerkes Observatory / Virtual Tour
This site describes the difference between reflective and refractive telescopes and includes a virtual tour of Yerkes Observatory which houses the largest refracting telescope in the world.
University of Chicago
University of Chicago: History of Yerkes Observatory
Read about the history of the Yerkes Observatory, which was run by the University of Chicago. This observatory houses one of the few research grade refractors in the world. The observatory was closed in October 2018 and discussions were...