John Augustus Roebling, an American engineer, born in Mühlhausen, Prussia, June 12, 1806, died in Brooklyn, N. Y., July 22, 1869. He was educated at the polytechnic school in Berlin, and emigrated to America and settled near Pittsburgh in 1831. He was assistant engineer on the slack-water navigation of the Beaver, and on the Sandy and Beaver canal and a feeder of the Pennsylvania canal, after which he spent three years in surveying the route across the Alleghanies adopted by the Pennsylvania Central railroad. He introduced the manufacture of wire ropes, first at Pittsburgh, afterward removing his establishment to Trenton, N. J., and their use in the construction of suspension bridges, his first work being the suspended aqueduct of the Pennsylvania canal across the Alleghany river, completed in May, 1845. He afterward constructed the Monongahela suspension bridge at Pittsburgh, and some suspension aqueducts on the Delaware and Hudson canal. In 1851 work was begun upon the Niagara bridge (see Bridge, vol. iii., p. 274), and in 1867 he completed the Cincinnati suspension bridge, which has a clear span of 1,057 ft.