[2][3] His mother was a descendant of Mayflower passengers Francis Cooke and Stephen Hopkins.

In 1838, he became professor of mathematics and astronomy at Philadelphia's Central High School and director of the observatory.

[1] In 1855, he became professor of mathematics and astronomy at the University of Pennsylvania, and in 1883 became vice-provost and dean of the college faculty.

[5] He received a Doctor of Laws, LL.D., honorary degree from the university in 1888 for his scientific work.

[1] He died on January 5, 1899, in Philadelphia and is buried in the Saint Luke's Episcopal Churchyard.