High Quality Content by WIKIPEDIA articles! Yale`s first observatory, the Atheneum, was situated in a tower, which from 1830 housed Yale`s first and America`s largest refractor, a 5-inch (130 mm) Dollond donated by Sheldon Clark. With this telescope Olmsted and Elias Loomis made the first American sighting of the return of Halley`s Comet in 1835. (August 31; seen in Europe August 6, but no news of this had reached America). The telescope was mounted on casters and moved from window to window, but it could not reach altitudes much over 30 deg above the horizon.