25. Halsted Observatory


As early as 1848, professor of astronomy Stephen Alexander urged the College to build an observatory, but construction of a structure based on his plans did not begin until 1866.  The Halsted Observatory was completed three years later, though it did not acquire its most important piece of equipment—a 23” refracting telescope—until 1882, after Alexander’s retirement.  Named for Princeton benefactor and Civil War general Nathaniel Norris Halsted, the observatory was used until 1932, when it was razed to make way for Joline Hall.  The stones from which Halsted was constructed were then used to build the new FitzRandolph Observatory, though one large stone from the outer wall of Halsted still marks the original site in what is now the Mathey College courtyard.  The 1882 telescope was also transferred to the new observatory where it needed only minor modifications for modernization, as it was impossible to create better quality lenses.  This equipment was not replaced with a 36” reflecting telescope until 1966.