Wilcox, Stephen (1830–1893)

US inventor who, with Herman Babcock, designed a water-tube boiler which was developed into one of the most efficient sources of high-pressure steam.

Wilcox was born in Westerley, Rhode Island. After leaving school he went to work on improving old machines and inventing new ones, such as a hot-air engine for operating fog signals. In about 1856, with his first partner D M Stillman, Wilcox patented a steam-tube boiler which was not entirely successful. Ten years later, with his boyhood friend Babcock, he designed an improved safety water-tube boiler, and they formed a company to manufacture this. Throughout his inventing career Wilcox acquired nearly 50 patents.

The Babcock–Wilcox boiler, patented 1867, had straight tubes inclined to the horizontal and connected together at their ends, through which the hot water gradually rose by convection. The firebox surrounded the tubes to give rapid heating, and there was a reservoir of hot water above the firebox and tubes, with steam above the water. These steam engines were used in the first American electricity generating stations and played an important part in the subsequent development of electric lighting.