Built in 1896 on the University of Illinois Urbana-Champaign campus, this observatory replaced a smaller earlier facility and became the home of the university’s astronomy department until 1979. Designed by Charles A. Gunn and equipped with a 12-inch Brashear refractor, it was first led by George W. Myers. Its greatest importance came under Joel Stebbins, whose work from 1907 to 1922, with Fay C. Brown and May Stebbins, pioneered the use of electricity and later photoelectric cells to measure stellar brightness more precisely. Research continued under Robert H. Baker, and in 1933 light from Arcturus gathered at its annex helped open the Chicago World’s Fair.