DRYDEN, HUGH LATIMER

(b. Pocomoke City, Maryland, 2 July 1898; d. Washington, D.C., 2 December 1965)

physics, aerodynamics.

Dryden’s parents, Samuel Isaac Dryden and Zenovia (Nova) Hill Culver Dryden, moved their family from Maryland’s Eastern Shore to Baltimore in 1907, where his father found work as a streetcar conductor. Dryden was educated in Baltimore public schools and at Johns Hopkins University, completing his B.A. in 1916, his M.A. in 1918, and his Ph.D. in physics in 1919. At the time he was the youngest person to receive a doctorate from Johns Hopkins, On 29 January 1920 he married Mary Libbie Travers; they had a son and two daughters. Throughout his career as a scientist and a public administrator, Dryden was a key figure at Calvary Methodist Church, Washington, D.C., where he was a licensed local preacher.

Dryden took a summer job as an inspector of munitions gauges with the National Bureau of Standards (NBS) in 1918; shortly thereafter he joined the staff of the bureau’s new wind tunnel section. At night he completed his doctoral studies under Joseph S. Ames of Johns Hopkins, who taught advanced courses at NBS. Research for his dissertation, “Air Forces on Circular Cylinders,” was conducted after hours at the NBS wind tunnel. This work described a series of experiments he had conducted on the drag and distribution of air flowing around cylinders perpendicular to the wind. Dryden was appointed chief of the Aerodynamics Section of NBS in 1920. His research on the problems of wind tunnel turbulence and boundary-layer flow caught the attention of the international engineering and scientific community. The work of Dryden and his colleagues demonstrated the effect of turbulence during the transition period from laminar to turbulent flow in the boundary layer near a solid surface. emphasizing the practicality of maintaining a laminar boundary layer over a large fraction of the surface of an aircraft to reduce drag.

With Lyman J. Briggs, Dryden took some of the earliest high-speed airfoil measurements during the mid 1920’s. His work at NBS led him to other engineering projects, such as calculating skyscraper wind loads and ensuring the structural integrity of propeller blades. He also conducted investigations designed to measure the acceleration of gravity.

In 1934 Dryden was named chief of the bureau’s Mechanics and Sound Division, which during World War II supported the development of guided glide bombs for the Office of Scientific Research and Development. In cooperation with the U.S. Navy, Dryden’s section developed the BAT radar homing missile, which was used in combat. This was the first large-scale research and development project Dryden had directed.

Dryden became associate director of NBS in 1946. The following year he joined the National Advisory Committee for Aeronautics (NACA), of which he had been a member since 1931, as director of research. He was named NACA’s director in 1949. During his tenure with the organization, NACA became the leading authority on supersonic flight. Highspeed wind tunnel research, flight testing of the X series aircraft, and study of the critical reentry heating problems experienced by high-and-fast-flying missiles and manned vehicles were conducted under Dryden’s direction. Dryden had become an administrator of scientists and engineers, and increasingly he devoted his energies to formulating broad research policy rather than pursuing his own research interests.

Concerning the problems of managing research, Dryden said, “Conventional management procedures are well adapted to operations in which the product consists of a series of nearly identical items.” But, he wrote, “A research laboratory produces ideas and new knowledge verified by experiment. Its reports are varied in nature and cannot be considered as nearly identical in scope, difficulty, or effort required.” Dryden feared that actions taken at high administrative levels, while entirely appropriate for the general operations of government, may “produce unexpected and often harmful results on the efficiency of research activities” (“Science and Public Administration: Viewpoint of a Scientist-TurnedAdministrator,” 21 March 1958). Fully realizing the difficulties, Dryden was prepared to play a key role in the U.S. response to the orbiting of the first artificial satellite. Sputnik I, by the Soviet Union.

When President Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958, Dryden—along with NACA’s other 8, 000 employees—was transferred to this new civilian agency. As deputy administrator he participated in the planning of the successful U.S. manned space program and emphasized the importance of international cooperation to space research. Dryden served as NASA’s technical negotiator from 1962 to 1965 in an attempt to forge a formal agreement with the Soviet Union.

In 1965, Dryden lost a four-year battle with cancer, bringing to an end his forty-five years of government service. He had been fond of saying that he had grown up with the airplane, but he did much more than passively “grow up” with aeronautics. His work at the National Bureau of Standards, NACA, and NASA had a great impact on the speed, safety, and efficiency of manned flight.

Among the many awards presented to Dryden were the Sylvanus Albert Reed Award (1940), the Presidential Certificate of Merit (1948), the Daniel Guggenheim Medal (1950), the Wright Brothers Memorial Trophy (1955), and the National Medal of Science (1965, awarded posthumously),

BIBLIOGRAPHY

I. Original Works. Dryden’s basic work on air flow is summarized in’Turbulence and the Boundary Layer, ’ in Journal of Aeronautical Sciences, 6 (1939), 85–105, the second Wright Brothers Lecture to the Institute of Aeronautical Sciences, Columbia University, 12 December 1938, His important technical writings have been collected at the Milton S. Eisenhower Library, Johns Hopkins University, See Richard K. Smith, ed., The Hugh L. Dryden Papers, 1898–1965; A Preliminary Catalogue of the Basic Collection (Baltimore, 1974), Other collections of his papers are at the NASA History Office Archives and the National Air and Space Museum Library, both in Washington, D.C.

II. Secondary Literature. An obituary with portrait and bibliography is Jerome C. Hunsaker and Robert C. Seamans. Jr., “’Hugh Latimer Dryden,” in Biographical Memoirs. National Academy of Sciences, 40 (1969), 35–68.

Linda Neuman Ezell