Page:Popular Science Monthly Volume 36.djvu/855

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S a citizen of Pennsylvania" says William Barton, in the preface to his "Memoirs of the Life of David Rittenhouse"; "as an inestimable public and private character; as a distinguished son of science, of great probity and extensive usefulness in society—in all these points of view, the history of Dr. Rittenhouse may be contemplated as holding a relationship with almost every object connected with science and art in his day that could in any way contribute to the well-being of mankind in general and his native country in particular." He, in fact, acquired a fame in the period of the infancy of American science, the nature and extent of which can hardly be realised in this day; and his gifts, then regarded as extraordinary, were always freely placed at the service of the public.

was born in Roxborough Township, near Germantown, Pa., April 8, 1732, and died in Philadelphia, June 26, 1796. He was descended from a family of paper-makers residing at Arnheim, Guelderland. His great-grandfather, William Rittenhouse, a Mennonite preacher, came from Holland with his family in 1687-'88; was the first Mennonite minister in Pennsylvania; and established the first paper-mill in this country, at the spot where David was born.

David was early put to work on the farm, and was plowing at fourteen years of age. An uncle dying had left him a chest of tools and a few books on arithmetic and geometry, with some manuscript mathematical calculations. These furnished palatable food to his mind, and his biographers tell of his having covered the handle of his plow and the fences around the field with his workings of the problems which they set before him. As the uncle mentioned above was his mother's brother, it is inferred that he inherited his genius from his mother's side. His mechanical talent was shown in his construction of a complete water-wheel in miniature when eight years old, a wooden clock when seventeen, and a clock with metallic works at a later age. His father was not disposed at first to favor the youth's tastes, but eventually he furnished him with money enough to buy a set of clock-making tools; and David built a workshop at Norriton, whither the family had removed, where he carried on the clock-making business for several years. He at the same time pursued his studies so diligently that he impaired his constitution, and contracted a pain that afflicted him all his life. Astronomy appeared to be his favorite study; and he was interested in optics and mechanical science. He discovered himself, independently, the method of fluxions, of which, in his imperfect knowledge of what Newton and Leibnitz had