The Mather Sundial, which sits in the center of McCosh Courtyard, is a replica of the Turnbull Sundial (1551) at Corpus Christi College, Oxford. It was given in 1907 by Sir William Mather, governor of Victoria University in Manchester, England, "to symbolize the connection not only between Oxford and Princeton, but between Great Britain and America." There are 24 different dials on it, and the frustum supports a globe (representing the earth) with a pelican on top (the symbol of Corpus Christi College).

At one time, the Mather Sundial was the province of seniors, who by custom enjoyed the exclusive privilege of sitting on its steps between classes.

(Adapted from A Princeton Companion and the Princetoniana Web site.)