Astronomer; born in Roxboro, Pa.
, April 8, 1732; was of German descent.
His great-grandfather established at Germantown
, in 1690, the first paper-mill in America
Accidentally falling in with instruments and mathematical books of a deceased uncle while working on his father's farm, David had mastered Newton
and independently discovered the methods of fluxions before he was nineteen years of age. He early became a skilful mechanic, and, at the age of twenty-three, planned and constructed an orrery, which was purchased by Princeton College.
He afterwards constructed a larger and more perfect one for the University
In 1763 he was employed in determining the Mason and Dixon's line
(q. v.), and afterwards fixed other State boundaries.
In 1769 the American Philo
sophical Society appointed him to observe the transit of Venus
He erected a temporary observatory for the purpose on the Walnut Street
front of the State-house.
It is said that the emotion of Rittenhouse
was so great at the apparent contact at the time of the transit that he fainted.
In Philadelphia Rittenhouse continued his manufacture of clocks and mathematical instruments
From 1777 to 1779 he was treasurer of Pennsylvania
; in 1791 he succeeded Franklin
as president of the American Philosophical Society; and from 1792 to 1795 was director of the United States Mint.
He was a member of the Academy of Arts and Sciences of Boston
He died in Philadelphia
, June 26, 1796.