TROWBRIDGE, William Petit, American engineer: b. in Oakland County, Mich., 25 May 1828; d. New Haven, Conn., 12 Aug. 1892. He was graduated at West Point in 1848, served there during the last year of his cadetship as assistant professor in chemistry, later as assist ant in the astronomical observatory, and in 1851 was assigned to the coast survey. His work on the Pacific Coast in 1853 embraced a series of magnetic and tidal observations covering a distance of over 1,300 miles, from San Diego to Puget Sound. In 1860, at Key West, Fla., he superintended the erection of the first perma nent self-registering magnetic observatory in the United States. After the outbreak of the Civil War he furnished minute descriptions of the rivers, harbors and inlets of the Southern coast to the War Department, gnd later was stationed at New York, where he superintended the accumulation and transmission of field supplies. Besides these duties he superintended the construction of fortifications at Willett's Point and at Governor's Island, and the repairs of Fort Schuyler. In 1870 he became professor
of mechanical engineering in the Sheffield Scien tific School at Yale, and later held a professor ship in the Columbia School of Mines, and at both institutions rendered an efficient service in the establishment and development of new courses of instruction. To him belongs the credit for the design of the first cantilever bridge, details of which are given in his work, (Proposed Plan for Building a Bridge across the East River to Blackwell's Island' (1869). A company was formed to carry out the scheme, but the financial crisis of 1873 put an end to the plan. He was the inventor of a coil-boiler, utilizing forced circulation of water, a principle that later came into use. His publications in clude 'Heat as a Source of Power' (1874) and 'Turbine Wheels' (1879).