Discover Yerkes Observatory, largest refracting telescope - YouTube
Refracting telescopes: Use lenses (refraction); Important concepts are focal length and apert… | Astronomical observatory, Astronomical telescope, Largest telescope
Yerkes Observatory Buildings, Instruments, Equipment, Grounds : Photographic Archive : The University of Chicago
Giant telescopes able to probe deeper into space - The Daily Gazette
Visual Observing With The 40-Inch Yerkes Refractor
40 inch telescope, Yerkes Observatory - Stock Image - C004/2128 - Science Photo Library
Yerkes Observatory Williams Bay Telescope Photograph by Tom Jelen - Fine Art America
Yerkes Future Foundation has big plans for Yerkes Observatory - Chicago Sun-Times
Wisconsin 101
The Not-Quite Closing of Yerkes Observatory - Sky & Telescope - Sky & Telescope
Yerkes Observatory | observatory, Williams Bay, Wisconsin, United States | Britannica
Yerkes Observatory - Wikipedia
Yerkes Observatory - Wikipedia
40 inch refracting telescope at Yerkes Observatory in Williams Bay, Wisconsin Stock Photo - Alamy
Yerkes Observatory | observatory, Williams Bay, Wisconsin, United States | Britannica
Inside The Yerkes Observatory: U Of C's 'Cathedral Of Science' | WBEZ Chicago
Wisconsin's Yerkes Observatory—stargazing through the world's largest refracting telescope
Yerkes Observatory – Williams Bay, Wisconsin - Atlas Obscura
Homepage - Yerkes Observatory
Wisconsin 101
Yerkes Observatory aims for resurrection as school for astronomy – Chicago Tribune
Changes at Yerkes Observatory, An Artifact of Wisconsin's Astronomical Glory Days | WUWM 89.7 FM - Milwaukee's NPR
Homepage - Yerkes Observatory
Yerkes Observatory is closing its doors | Astronomy.com
Yerkes Observatory – Williams Bay, Wisconsin - Atlas Obscura
