James Gayley (born Oct. 11, 1855, Lock Haven, Pa., U.S.—died Feb. 25, 1920, New York, N.Y.) was an American metallurgist who invented a device to ensure uniform humidity in the air stream going into blast furnaces.
Gayley enjoyed a long career in a variety of positions with steel companies. Beginning as a chemist for the Crane Iron Company, in Pennsylvania, he had, by the age of 30, worked his way up to superintendent of blast furnaces at a Pennsylvania steel plant that later became Carnegie Steel Company. By 1901 he was first vice president of the newly formed United States Steel Corporation (which included Carnegie Steel Company).
Throughout his career Gayley developed numerous devices to improve the construction of blast furnaces and the quality of iron produced in them, the most important of which was a device (patented with improvements 1894–1911) to prevent water vapour in the air from entering the furnace with the air blast and absorbing heat; previously, such vapour (a particular problem in regions with hot, humid summers) had harmed the quality of the pig iron. Gayley’s basic idea, although improved upon or varied by his successors, has remained in wide use.
In addition to his many inventions improving blast furnaces, Gayley was a prolific author of technical papers on the subject. With the gains from his varied career, he endowed the Gayley Hall of Chemistry and Metallurgy at Lafayette College, Easton, Pa.