Princeton University

By the numbers

Princeton’s orrery

The Rittenhouse Orrery, a mechanical model of the solar system built in 1771, hangs on a wall near the entrance to Peyton Hall.

• David Rittenhouse, a Pennsylvania clockmaker and self-taught astronomer, designed and built Princeton’s orrery. President John Witherspoon purchased the device for approximately 220 pounds, taking advantage of an opportunity that presented itself when the provost of the College of Philadelphia (now the University of Pennsylvania) decided that this price was excessive.

• The orrery instantly became Princeton’s most valuable asset but was almost destroyed during military occupation of Nassau Hall by the Continental Army during the Revolutionary War.

• After serving as a notable teaching aid for the first half of the 19th century, the Rittenhouse Orrery’s usefulness in the classroom faded, and it became a mere curiosity. It was included in Princeton’s exhibit at the Chicago World’s Fair in 1893, and then packed away upon its return.

• Its whereabouts were a mystery until 1948, when carpenters working in McCosh Hall discovered the orrery still in its World’s Fair shipping box, and brought it to astronomy professor Newton Pierce for identification. Because of the damaged condition of the orrery, its discovery was not publicized until the spring of 1951.

• Thanks to the generosity of Bernard Peyton, a member of the class of 1917, the orrery was restored and equipped with electric motors. After a temporary stay in Firestone Library, where it formed the focus of an exhibition in 1954, it was placed in the lobby of the newly opened Peyton Hall, which was built in 1966 to house the astrophysical sciences department.

Source: Mudd Manuscript Library Web site: www.princeton.edu/mudd.