born July 31, 1803, Långbanshyttan, Swed.
died March 8, 1889, New York, N.Y., U.S.
Swedish-U.S. naval engineer and inventor.
He moved to England in 1826, where he constructed a steam locomotive (1829) and later devised a caloric engine and patented a screw propeller. He immigrated to the U.S in 1839. During the Civil War he proposed, designed, and built a novel warship, the Monitor . Its battle with the Confederacy's Merrimack led the government to place an order for many more such vessels. Wholly steam-powered and with a screw propeller and an armoured revolving turret, it set a new pattern for U.S. warships that continued until the 20th century. He later developed a torpedo and investigated solar-powered motors.