EVANS, Oliver, inventor, born in Newport, Delaware, in 1755; died in New York City, 21 April 1819. He was apprenticed to a wheelwright, and before he had reached the age of manhood the construction of a land carriage to be propelled without animal power began to occupy his attention. At the age of twenty-two he invented a machine for making card teeth. Two years later he entered into business with his brothers, who were millers, and in a short time invented the elevator, the conveyer, the drill, the hopper boy, and the descender, the application of which to mills worked by waterpower affected a revolution in the manufacture of flour. In 1786'7 he obtained from the legislature of Maryland and Pennsylvania the exclusive right to use his improvements in flouring mills, and Maryland gave him a similar privilege with regard to steam carriages.

It was not till 1799 or 1800 that he was able to set about the construction of a steam carriage. Finding that his steam engine differed in form as well as in principle from those in use, he secured a patent, and applied it to mills more profitably than to carriages, This was the first steam engine constructed on the high-pressure principle; and to Evans, who had conceived the idea of it in early life, and in 1787 and again in 1794'5 had sent to England drawings and specifications, the merit of the invention belongs, although it has been common to assign it to Vivian and Trevithick, who had had access to Evans's plans. In 1803'4, by order of the board of health of Philadelphia, he constructed the first steam-dredging machine used in America. It consisted of a scow, with a small engine to work the machinery for raising the mud. The machine, which he named the "Orakter Amphibolos," propelled itself on wheels to the Schuylkill, a distance of one and a half mile, was fitted with a paddlewheel in the stern, and navigated the River to its junction with the Delaware. This is believed to have been the first instance in America of the application of steam power to the propelling of land carriages. He predicted the time when such carriages would be propelled on railways of wood or iron, and urged the construction of a railroad between Philadelphia and New York, but was always prevented by his limited means from prosecuting his mechanical experiments to the extent he desired. He was the author of " The Young Engineer's Guide" (Philadelphia, 1805; translated into French, Paris, 1821): and of the "Miller and Millwright's Guide" (Philadelphia, 1797; Paris, 1830; 14th ed., with additions by Thomas P. Jones); and he also published a description of an improved merchant flouring mill, by C. and O. Evans (Philadelphia, 1853).