Thomas Ewbank, an American writer on practical mechanics, born at Barnard Castle, Durham, England, March 11, 1792, died in New York, Sept. 16, 1870. At the age of 13 he was apprenticed to a tin and copper smith, and about 1819 emigrated to New York. In 1820 he commenced the manufacture of metallic tubing in that city, and retired in 1836 to devote himself to literary and scientific pursuits. In 1842 appeared his Descriptive and Historical Account of Hydraulic and other Machines, Ancient and Modern; including the Progressive Development of the Steam Engine," of which the loth edition was published in 1870. In 1845-'6 he made a visit to Brazil, recording his observations in a work entitled "Life in Brazil," with an appendix descriptive of a collection of American antiquities, New York (1850). From 1849 to 1852 he was United States commissioner of patents. He also wrote "The World a Workshop, or the Physical Relation of Man to the Earth" (1855); Thoughts on Matter and Force" (1858);

Reminiscences in the Patent Office" (1859); and a variety of miscellaneous essays on the philosophy and history of inventions, which appeared chiefly in the Transactions of the Franklin Institute." His Experiments on Marine Propulsion, or the Virtue of Form in Propelling Blades," was reprinted in Europe. As a member of the commission to examine and report upon the strength of the marbles offered for the extension of the national capi-tol, he made some suggestions which led to the discovery of a means of greatly increasing the power of resistance to pressure in building stones. He was one of the founders of the American ethnological society.