Ericsson, John at English => English (The Britannica Concise) Of Explained:
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 emigrated to the U.S in 1839. During the Civil War he proposed, designed, and built a novel warship, the Monitor. Its battle with the Merrimack led the government to place an order for many more such vessels. Wholly steam-powered and with a screw propeller and an armored revolving turret, it set a new pattern for U.S. warships that continued until the 20th cent. He later developed a torpedo and investigated solar-powered motors.