RITTENHOUSE, David (1732-1796). American astronomer, b. Germantown, Pa. Great-grandson of William Rittenhouse. Gained reputation by building two
orreries, one for Princeton U. (c.1767) and one for the U. of Pennsylvania. Built observatory and a transit telescope, believed to be first telescope made in America, to observe the transit of Venus (1769). Inventor of
a collimating telescope (1785); one of earliest to use spider webs as reticle in the eyepiece of a telescope. During Revolutionary War, served as member of Pennsylvania assembly (1776) and president of the council of
safety (1777); treasurer of Pennsylvania (1777-89). First director, U.S. Mint (1792-95). President, succeeding Benjamin Franklin, of American Philosophical Society (1791-96).