WILSON, HAROLD ALBERT

(b. York, England, 1 December 1874; d. Houston, Texas, 13 October 1964)

physics.

Harold Albert Wilson was the only son of a North Eastern Railway clerk who later became a district manager, and Anne Gill, daughter of a local farmer and innkeeper. He had one sister, Lilian, who married Owen Willans Richardson, a physicist and Nobel Prize winner whose work was closely related to Wilson’s. Wilson attended a private boys’ school and later, when he was about twelve, entered a private preparatory school called St. Olave’s, at which he stayed until he was nineteen, the last two years as an assistant mathematics master. At school he took lessons in chemistry and got some practical knowledge of machines such as railway engines and steam rollers, but his passion for science was stimulated more by his home than his schools. Wilson’s father was an enlightened man who studied mathematics and philosophy, and encouraged the development of his son’s scientific interests. By the time he left St. Olave’s, Wilson had done chemical experiments in his home lab and taken evening classes in chemistry at the Railway Institute in York, receiving the advanced certificate in elementary inorganic chemistry.

In 1893 Wilson entered Victoria University College at Leeds, where he studied mathematics, physics, chemistry, and biology. It was at Leeds that he started, with Professor Arthur Smithells, research on the electrical conductivity of flames that he continued, with varying intensity, for more than thirty years. After receiving B.Sc. degrees in physics and chemistry, in September 1897 Wilson arrived at Cambridge to work at the Cavendish Laboratory with J. J. Thomson.

This was an exciting time for Cavendish physics. Thomson and Rutherford had just published their fundamental paper on conduction by gaseous ions produced by X rays, and the concept of the electron was taking concrete shape; C. T. R. Wilson (unrelated to Harold) had invented his cloud chamber, making it possible to observe trajectories of single charged particles; Paul Langevin was studying the properties of the ions produced in gases by X rays, and shared his laboratory with Rutherford and H. A. Wilson. The years at the Cavendish, interrupted by an eight-month visit at Jacobus Van’t Hoff’s laboratory in Berlin in 1899, were among the most productive in Wilson’s scientific career. He investigated the mobility of ions in flames, studied electric discharge in rarefied gases, measured the Hall effect in gases, and, following J. J. Thomson, made an attempt to determine the charge of the electron by using the cloud chamber. The experiment, in which he observed the fall of the condensation drops in the vertical electric field and in its absence, was a forerunner of the more precise technique developed by Robert Millikan. Wilson, however, used water instead of oil droplets and observed the top edge of the condensation cloud instead of individual droplets. His result was about 35 percent too small, mostly owing to the effect of evaporation during the experiment.

In 1904 Wilson joined the faculty of King’s College, London, and in the following year was named professor and head of the department of physics. In 1906 he was elected a fellow of the Royal Society. Three years later he left England for Canada, to accept a professorship at McGill University; and in 1912, when the Rice Institute (now Rice University) was established in Houston, Texas, Wilson became one of its eleven original professors. In the same year he married Marjorie Patterson Smyth, a former gold medalist in physics at McGill. He remained at Rice for the rest of his academic career, leaving it for only one year (1924) for the chair of natural philosophy at Glasgow, once occupied by Kelvin. He gained a reputation as an excellent teacher and developed an active research center.

Wilson’s professional interests ranged from practical problems such as oil cracking and sound perception (during World War I he designed an underwater sound receiver, later developed by General Electric for use in antisubmarine warfare) to the theory of relativity and the structure of the nucleus. He was best known for his research on the conductivity of flames, but after 1932 nuclear physics became his primary focus. During World War II, Wilson did research for the Manhattan Project.

Although an experimentalist, Wilson had well-developed mathematical skills. He used them mostly in a semiempirical manner for interpretation of his experimental results. He belonged to the last generation of classical physicists who witnessed the full triumph of the modern, quantum-relativistic vision of the world. Like many others he did not immediately embrace revolutionary ideas. As late as 1928 he believed that atoms could be viewed as absorbing light like simple damped oscillators; in 1910 he tried to explain the results of the Michelson-Morley experiment without resorting to relativity; and in 1921 he still referred to ether in discussing electromagnetism. However, Wilson later accepted the relativity and quantum theories. Upon his retirement he chose relativity as a subject of his teaching to a small class of Rice students who met at his home.

Wilson was naturalized as an American citizen in 1931. In 1947 he was named professor emeritus but continued to teach part-time until 1964. He died six weeks before he would have become ninety years old. He was survived by his wife, two sons, and two daughters.

BIBLIOGRAPHY

I. Original Works. Thomson’s article (see below) includes a bibliography of Wilson’s works. It consists of ninety-nine research papers and four books: The Electrical Properties of Flames (London, 1912); Experimental Physics (Cambridge, 1915); Modern Physics (London and Glasgow, 1928); and The Mysteries of the Atom (New York, 1934).

Archival materials held at the American Institute of Physics in New York include undated Biographical Notes of H. A. Wilson (21 pp.) and a transcript of an interview conducted with Wilson by G. Phillips and W. J. King on March 3, 1964 (28 pp.).

II. Secondary Literature. G. P. Thomson, “Harold Albert Wilson, 1874–1964,” in Biographical Memoirs of Fellows of the Royal Society, 11 (1965), 187–201, is the only published biography of Wilson. A brief obituary is in Physics Today, 18 , no. 1 (1965), 154.

Kris Szymborski