Hopkins Observatory 1904
Hopkins Observatory in 1904

In 1834, Prof. Albert Hopkins went to England, with the permission of the trustees of Williams College, to search for astronomical apparatus. From 1836 to 1838, Prof. Hopkins enlisted some of his students to build by hand a permanent observatory, which now also contains the Milham Planetarium.

Exterior of Hopkins Observatory in 2008
Hopkins Observatory in 2008

The original telescope was replaced by a 7-inch refracting telescope, which was built in 1852 by the Alvan Clark firm. It was Clark’s first professional telescope, made when the Williams commission led him to leave his job and set up his telescope-making company. A view inside the dome shows the historic telescope up close. Decades later, the Clark company made the largest refracting telescope (that is, a telescope with a lens) in the world. The Clark refractor was restored for the Observatory’s sesquicentennial celebration. The main telescope of the Hopkins Observatory, for the use of current Williams College students, is a 24-inch reflector that is located on the roof of the physics/astronomy building in the Science Quadrangle. Also see the articles “Williams College’s Hopkins Observatory: the oldest extant observatory in the United States” by Jay Pasachoff in the Journal of Astronomical History and Heritage 1(1): 61-78, 1998, and Early American Observatories: Which Was the First Astronomical Observatory in America? by Willis I. Milham (Williamstown, Massachusetts: Williams College, 1938), pp. 38-44.

Group photo of 1937 American Astronomical Association meeting
The 58th meeting of the American Astronomical Association in front of Hopkins Observatory in September 1937.