Elmer Ambrose Sperry

• Born: October 12, 1860 (baptized)
• Birthplace: Cortland, New York
• Died: June 16, 1930
• Place of death: Brooklyn, New York

American engineer

One of the most prolific inventors in U.S. history, Sperry invented an improved gyrocompass and contributed to significant military projects in the lead-up to World War I. He also possessed the business acumen to turn his inventions into lucrative investments.

Primary fields: Mechanical engineering; military technology and weaponry; navigation

Primary inventions: Gyrocompass; gyrostabilizer; flying bomb

Early Life

Born in Cortland, New York, Elmer Ambrose Sperry tinkered with mechanical devices from an early age. He was fascinated by the machine shops in his hometown and spent many days learning how machines worked. Recognizing the young boy’s potential talents, the local YMCA sponsored Sperry on a trip to the 1876 Centennial Exposition in Philadelphia. The central feature of the exposition was Machinery Hall, a massive building filled with all the mechanical and technological achievements of America’s industrial age. Amid the massive machines and whirring cogs, Sperry discovered where his future lay.

Sperry subsequently attended two years at Cortland Normal School (now State University of New York College at Cortland), followed by a year at Cornell University. At Cornell, he concentrated on electrical engineering. In 1880, he moved to Chicago, where he founded the Sperry Electric Company to manufacture dynamos and arc lamps.

Life’s Work

Sperry’s new firm specialized in urban lighting systems, and Sperry designed the electric street lighting for a number of large American cities, earning him a fortune in contracts. In 1887, Sperry married Zula Goodman, with whom he had four children. The next year, he established the Sperry Electric Mining Machine Company to manufacture machines for mining. After observing many American mines still using obsolete steam machinery or even brute manpower, Sperry began to design systems to electrify the mines. Starting with electric lighting to illuminate deep shafts, he followed with electric drills, hoists, and sorters that sped up the pace of production and improved safety.

Sperry next turned his attention toward electric streetcars. In 1890, he organized the Sperry Electric Railway Company, and he designed a streetcar that used electricity more efficiently and could run longer on a single charge than other models. He first sold the design to the city of Cleveland, Ohio, and other cities purchased his design after seeing its success. Sperry would continue to develop railroad technology for the rest of his life. In 1911, he established the Sperry Rail Service, which developed devices for testing railroad lines and locating rail defects to reduce accidents.

Sperry also improved on existing searchlights, using better lens design to increase their brightness without increasing their weight. The searchlight was adapted to serve as a beacon in a number of lighthouses and airfields in the early twentieth century, giving Sperry still more public exposure.

His greatest achievement came in 1911, when he received a U.S. patent for his gyrocompass, a nonmagnetic compass that indicatestrue north. In 1910, Sperry founded the Sperry Gyroscope Company in Brooklyn, New York, and his gyrocompass underwent its first trial in 1911, when it was installed on the U.S. battleship Delaware. Before Sperry’s invention, ships relied onmagnetic compasses. These devices do not point to true north; instead, they point to magnetic north. The true North Pole is the axis around which the Earth revolves, while the magnetic North Pole is the positive pole of the Earth’s magnetic field, which is some distance from the North Pole. Thus, while magnetic compasses are generally accurate and practical for most basic purposes, they are not precise enough when speed and efficiency are of the essence.

Magnetic compasses were useful on ships made of wood, but they were practically worthless on iron ships, which appeared in the nineteenth century. The metal hull of the ship affected the magnetic field around the vessel, degrading the accuracy of the magnetic compass. Electrical systems on the ship also hampered the compass’s accuracy. Sperry’s compass, harnessing the gyroscope, solved the problem. The spinning gyroscope aligned itself to the spinning of the Earth, maintaining a north-south orientation. With the gyrocompass locked onto the north-south line, any relative movement could be measured to determine course direction, measured as degrees off the north-south alignment. Consequently, not only were north and south determined accurately, but relative movement east-west also was very precise.

Sperry’s gyrocompass design was an improvement on German scientist Hermann Anschütz-Kaempfe’s gyrocompass. When Sperry tried to sell his version to the German navy, Anschütz-Kaempfe sued Sperry for patent infringement. In 1915, a German court ruled in Anschütz-Kaempfe’s favor, largely because, with World War I going on, Sperry refused to risk his life to go to Germany to defend himself. The U.S. Patent Office upheld his U.S. patent, however, and Sperry continued to produce gyrocompasses. Gyrocompasses can still be found on ships today, although satellite navigation has largely supplanted them.

Sperry found other applications for the gyroscope. In 1913, he received a patent for a gyrostabilizer, a device to control the roll, pitch, and yaw of a moving ship. Before Sperry’s invention, even the largest ships were at the mercy of the sea. Sperry’s gyrostabilizer was a powered gyroscope mounted in the center of the ship’s hull and attached by linkages to fins mounted on the sides of the ship. At sea, the gyrostabilizer measured the movement of the hull relative to the stable gyroscope. By accurately measuring how much the ship moved, the gyrostabilizer could then actuate the external fins to dampen the roll, pitch, or yaw. The device could not completely compensate for a ship’s movement, but it smoothed out the ride considerably. Moreover, as an automatic device, it acted more quickly and more precisely than could a human at the fin controls. In the 1920’s, Sperry invented “Metal Mike,” the first automatic pilot for ships. Sperry’s autopilot allowed a ship to follow a straight course and to maintain a set speed without direct intervention. This made it easier to steer a ship because helmsmen no longer had to constantly make minute adjustments to the ship’s wheel and throttle.

Like many scientists and inventors, Sperry worked on military projects during World War I. His most prominent invention was a precursor to the cruise missile. Sperry, working with his son Charles and Peter Cooper Hewitt, developed the “flying bomb,” an unmanned aerial vehicle also known as an aerial torpedo. Hewitt was a pioneer in radio technology, and Sperry believed that Hewitt could provide the expertise to use radio waves to control a gyrostabilizer by remote control. Glenn H. Curtiss, the famed aircraft designer, aided with the aircraft components. After a number of failed flights in 1917, the group found success on March 6, 1918. The flying bomb flew more than half a mile under radio control and struck its intended target. Using a modified Curtiss N-9 airframe, the flying bomb flew for nearly eight miles in a test in October, 1918. However, the war ended a month later, the flying bomb project was canceled, and the world would have to wait for the emergence of the cruise missile. The project got Sperry interested in automatic control for airplanes, and he developed several basic designs based on his ship autopilots. Sperry was still working on the project when he died in 1930 at the age of sixty-nine.

Impact

During his lifetime, Sperry founded eight companies and received some four hundred patents. His inventions made rail and sea travel safer, opening the world for exploration by common people. Many of his inventions, including his autopilot designs, utilized gyroscopic principles. His most famous invention, the gyrocompass, was used by Allied navies during the two world wars. In his will, Sperry left a large portion of his estate to the YMCA, the organization that opened his eyes to the future of mechanical engineering.

Bibliography

Brown, David E. Inventing Modern America: From the Microwave to the Mouse. Cambridge: MIT Press, 2002. An homage to American inventors of the twentieth century, this book places Sperry within the context of developmental inventions, revealing how earlier inventions shaped Sperry’s work and how Sperry’s invention of the gyrocompass in turn influenced inventors after him.

Fahrney, D. S. The History of Pilotless Aircraft and Guided Missiles. Washington, D.C.: Department of Navy, Bureau of Aeronautics, 1958. The only significant study of Sperry’s World War I efforts to create a guided weapon, the book attempts to demonstrate that the true origins of guided weapons began in the United States, not Germany, with its infamous V-1 and V-2 rockets.

Hughes, Thomas Parke. Elmer Sperry: Inventor and Engineer. Baltimore: The Johns Hopkins University Press, 1993. The only general biography of Sperry ever written, this book concentrates on the whole spectrum of Sperry’s career. Hughes does not focus on any particular invention or period of Sperry’s life.