quadrangle was formed with East College, South College, and the Hopkins Observatory.
The Olmsted Brothers design firm played a large part in shaping the campus design and architecture. In 1902, the firm was commissioned to renovate a large part of campus, including the President's House, the cemetery, and South College; as well as incorporating the George A. Cluett estate into the campus acreage. Although these campus renovations were completed in 1912, the Olmsted Brothers would advise the gradual transformation of campus design for six decades. The present-day grounds layout reflects much of the design intent of the Olmsted Brothers.
Williams College is the site of the Hopkins Observatory, the oldest extant astronomical observatory in the United States. Erected in 1836–1838, it now contains the Mehlin Museum of Astronomy, including Alvan Clark's first telescope (from 1852), as well as the Milham Planetarium, which uses a Zeiss Skymaster ZKP3/B optomechanical projector and an Ansible digital projector, both …
