John Ericsson (1803-1889), Swedish-born American engineer and inventor, perfected the screw propeller and constructed radically designed warships, notably the ironclad "Monitor."

John Ericsson was born in Långbanshyttan, Värmland Province, on July 31, 1803. He began as an iron miner but showed an aptitude for machinery construction, drafting, and engraving. After work as a surveyor on the Göta Ship Canal, he became an army topographic officer in 1820.

In 1826 Ericsson went to London, where he worked mainly on engines and on locomotives and screw propulsion for boats, receiving 14 patents. English railroad builders kept him profitably at work.

To devise a means of using heat more efficiently than did steam engines, Ericsson applied flame directly in a "caloric" engine. His most lucrative invention was a steam fire engine. To improve marine engines and keep propulsion apparatus underwater, he designed a screw propeller (patented 1836) which was more efficient than a paddle wheel, ensured better engine performance, and made larger ships possible. In 1836 the speed of his model vessel exceeded 10 miles per hour. His screwpropelled ships were used on English rivers, and some were taken to America; yet the British navy rejected his designs. In 1839 he migrated to America to build naval vessels.

Ericsson won a prize in 1840 for the best-designed steam fire engine. He adapted twin screw propellers to a vessel, and by 1844 there were 25 such boats on American waters. In 1844 he completed the 1,000-ton iron frigate U.S.S. Princeton, the first screw-propelled warship and the first with engines and boilers underwater, out of firing range. A coal burner with a self-adjusting gunlock to compensate for roll, it was pronounced a shipbuilding marvel. But on a trial run the 12-inch wrought-iron gun (not designed by Ericsson) exploded and killed the secretaries of state and Navy and four others. This tragedy stigmatized Ericsson and delayed the building of American steam naval ships.

At the London Crystal Palace Exposition of 1851 Ericsson entered a pyrometer that measured very high temperatures, a model gas engine, an engine barometer with an alarm, a sounding instrument, a distance measurer, and a compass.

Another blow to Ericsson's career occurred in 1854, when the Ericsson, equipped with caloric engines, capsized in a storm. Though the engines were too heavy for ship propulsion, they were economical and thousands were used to pump water for homes.

Ericsson regained prestige with the Monitor. Napoleon III had rejected his model ironclad warship in 1854. A U.S. Navy board reluctantly granted him a contract to construct the craft for Union use in the Civil War: the Monitor was launched in January 1862. It arrived at Hampton Roads (Norfolk) on March 9 in time to drive off the Confederate ironclad, the Merrimac. This first, historic battle between steam-driven ironclads was a turning point in naval technology. For the rest of the war Ericsson designed and built ironclads.

After the war Ericsson built monitors for other nations and gunboats for Spain. By 1878 his torpedo boat, the Destroyer, was ready. It could outrun ironclads, could partially submerge, and fired a dynamite torpedo projectile underwater. During Ericsson's lifetime the U.S. Navy displayed no interest in it.

Ericsson later worked with solar energy, gravitation and tides, high-speed engines for electric lighting, a marine surface condenser, and forced-draft ventilating fans. His solar engine was never commercialized.

Ericsson died in New York City on March 8, 1889. His remains were reinterred at Filipstad, Sweden.

Further Reading

• A favorable biography of Ericsson is Ruth M. White, Yankee from Sweden: The Dream and the Reality in the Days of John Ericsson (1960). George Iles, Leading American Inventors (1912), includes a short account of Ericsson. For a detailed, illustrated account of the evolution of ironclad warships and screw propellers see James Phinney Baxter III, The Introduction of the Ironclad Warship (1933). Ericsson's ironclads are depicted in most illustrated histories of the Civil War.