Chicago Astronomical Society
The Chicago Astronomical Society (CAS) was founded by scholars and leaders in the arenas of business and politics in 1862 to advance the scientific knowledge of astronomy. The founders knew that a primary step in their mission was to build an observatory from which to conduct original research in the field. Inquires were made and the prime telescope maker in the United States was identified as Alvin Clark And Sons of Massachusetts. During negotiations Mr. Clark advised that he had completed and tested a lens of 18 inches diameterthe largest apochromatic lens in the worldfor the observatory of the University of Mississippi.
Previously, arrangements were made by CAS to acquire vacant land at 35th Street and Cottage Grove Avenue on the far south side of Chicago, actually on the campus of the first University of Chicago. Contracts were let for the construction of an observatory building and for the crafting of an equatorial mount and optical tube to hold the Clark lens. Professor Hans —, a renowned astronomer from Germany was hired to direct studies and research at the CAS observatory. Professor Hans made several discoveries of physical double stars. He began parallax studies of some of the brighter stars and was able to estimate their distances from Earth.
For more information, please visit http://www.chicagoastro.org