LEWIS, WARREN KENDALL

(b. Laurel, Delaware, 21 August 1882; d. Plymouth, Massachusetts, 9 March 1975),

chemical engineering, distillation, fluidized-bed catalytic cracking, continuous automatic chemical processing.

According to Ralph Landau, a distinguished chemical engineer who began his career at the M.W. Kellogg Company, one of the first American engineering firms to specialize in the design and development of plants for the modern chemical and oil industries, Lewis “virtually single-handedly created modern chemical engineering and its teaching methodology” (1991, p. 49). “Doc” Lewis converted nineteenth-century industrial chemistry into twentieth-century chemical engineering. He did so by using the new physical chemistry initiated in Europe by Wilhelm Ostwald (and taught in the United States by his student, Arthur A. Noyes), and crucially, by establishing the new concept of unit operations, developed by William H. Walker.

In 1920, Lewis was appointed chairman of the new Chemical Engineering Department of the Massachusetts Institute of Technology (MIT). A good university administrator, a successful and respected teacher, a sought-after technical consultant with scores of patents to his name, and an enthusiast for the scientific method, he promoted the role of the engineer in society while acknowledging the importance and difficulties of human relations in industry. Lewis’s seminal work on the distillation and the cracking of petroleum provided the foundations of the modern oil processing industry. A religious man, Lewis never stopped trying to reconcile his faith with his profound belief in science. His numerous honors include membership in the National Academy of Sciences (1938), the Priestley Medal of the American Chemical Society (1947), the President’s Medal for Merit (1948), the Gold Medal of the American Institute of Chemists (1949), and honorary doctor of science degrees from the University of Delaware, Harvard University, and Princeton University.

Childhood and Education . Lewis was born into a middle-class farming family, the only child of Martha Ellen Kinder Lewis, who ran her own millinery business, and Henry Clay Lewis. As he grew up in the 1880s and 1890s, Warren and his parents expected that he would inherit the farm that had been in the family since the eighteenth century. To prepare young Warren for a college education in the agricultural arts, he was sent at age fifteen to live with a cousin in Newton, Massachusetts, so that he could attend the local high school, which had a good reputation. Lewis was not immediately a star pupil, but he thrived on competition and eventually chose to enroll at MIT in Cambridge. Because no agronomy course was offered, Lewis opted for a mechanical engineering major, changing later to chemical engineering.

William H. Walker, a graduate of Pennsylvania State College with a PhD in organic chemistry from the University of Göttingen in Germany, taught analytical chemistry at MIT until 1900, when he left to enter into a partnership with the consultant Arthur D. Little. Walker and Little were convinced that the chemistry departments of MIT and other institutions should change their curricula to fit better with the needs of various industries, based on the chemical processes that they used. At the time, MIT offered several chemical engineering options, each one tailored to only one type of chemical manufacturing.

Walker believed that the teaching method of his predecessor at MIT, Frank H. Thorp, was wrong. “What an industry needed,” Walker wrote, “was not a man who had been taught what that industry already knew, but rather a man who was trained to do what the industry had not been able to do” (p. 2). Walker’s vision of a chemical engineer was a man who had been trained not only in physics and chemistry, but also in applying his knowledge to solve whatever industrial problems arose. Walker met opposition in academia and industry, but he returned to teach at

MIT in 1903 “to prove the soundness of [his] idea” (p. 2). He reconstructed the institute’s Course X as a “general education course without options” (p. 2)

Writing in 1934 about his changes to the chemical engineering course, Walker recalled that he “cut such courses as mechanical drawing, analytical chemistry, shop and foundry practice, and introduced all the physical chemistry that was then available and greatly strengthened the courses in organic and advanced inorganic chemistry. I then organized a laboratory course in industrial chemistry which was designed to teach method of attack in the solution of industrial problems through the application of chemical engineering already acquired. This was the beginning of the [modern] course in chemical engineering” (p. 2). Walker used George F. Davis’s A Handbook of Chemical Engineering (2 vols., 1901–1902) as a model for organizing the material for his revised Course X.

Walker hired Lewis as a research assistant before Lewis had graduated in 1905. With a Swett Fellowship and an Austin Traveling Fellowship from MIT, Lewis moved to Breslau University in Germany for his PhD work, supervised by Richard Abegg (a pupil of Ostwald, Svante Arrhenius, and Walther Nernst). He successfully defended his fifty-five-page dissertation on physical chemistry, “Die Komplexbildung zwischen Bleinitrat und Kali-umnitrat” (The complexes of lead and potassium nitrates) in July 1908.

Early Career . In 1910, Lewis was appointed assistant professor of industrial chemistry at MIT. As Walker said later, the new Course X became synonymous with modern chemical engineering and “was copied more or less by many other institutions” (p. 2). Asked in 1905 to give an industrial chemistry course at Harvard, Walker decided to introduce the concept known (from about 1915) as unit operations, standard processes such as crushing and grinding, filtration, distillation, crystallization, and drying, which had applications in chemical industries with many different products. Walker’s lecture notes were a foundation for the groundbreaking textbook, Principles of Chemical Engineering, coauthored with Lewis and William H. McAdams, a student of Lewis, and eventually published in 1923.

In 1911 Walker and Lewis published an article in the Journal of the American Chemical Society titled “A Laboratory Course of Chemical Engineering,” a description of a four-year undergraduate course intended to demonstrate general chemical engineering principles (such as the economic importance of minimizing heat losses). Walker was in charge of chemical engineering at MIT from 1912 to 1920; he believed that the institute should concentrate on applied sciences and the training of builders and leaders of industry. With those objectives, Walker and Lewis, supported by Little, founded the MIT School of Chemical Engineering Practice in 1916 to give undergraduates “the engineering equivalent of the hospital internship” (Lewis, 1953, p. 700). Lewis realized that simply learning the scientific principles of physics, chemistry, and engineering would not easily enable students to apply their knowledge to complex problems in industrial chemical engineering, but in the practice school, especially by focusing on unit operations, they would understand how commercial processes could be analyzed and quantified, and thereby improved and made more profitable. The practice school required significant commitments from MIT, the students, and industry. George Eastman agreed to provide three hundred thousand dollars for equipment, and a number of MIT stations were established at chemical plants in various industries, staffed by MIT teachers.

Well after his own retirement, Lewis said that the payoff from Walker’s reorganization of the MIT chemical engineering curriculum in the early years of the twentieth century came during World War I. German shipping was subject to an Allied blockade, so that many imports from Europe had to be produced in America; furthermore, the demand for explosives multiplied as Europe’s Allied powers turned to the United States for supplies. At the same time, the growth of the automobile industry (total car production in the United States in 1918 exceeded 800,000) was pushing up the demand for gasoline.

The provision of the Hague Convention of 1899 that outlawed projectiles containing poison gas held only until World War I; by then, most European governments had a gas capability. The Boston Evening Transcript of 11 January 1919 proclaimed that “poison gas will remain indefinitely one of the weapons of civilized warfare.” Two months before the United States entered the war, Van H. Manning, director of the U.S. Bureau of Mines, advised the War Department to prepare for gas warfare; the National Research Council (NRC) formed a committee on gases, chaired by Manning. MIT academic staff were co-opted. The physical chemist Arthur A. Noyes chaired the NRC in Washington, D.C.; Walker, a commissioned colonel in charge of the new Chemical Warfare Service, built and ran the Edgewood Arsenal near Baltimore, the U.S. Army’s first chemical warfare facility; and Lewis became the civilian head of the Service’s Gas Defense Production Division.

In 1920 a separate Chemical Engineering Department was created at MIT under Lewis’s chairmanship. Three years later the pioneering chemical engineering text, Principles of Chemical Engineering, was published, and for years afterward, chemical engineering was particularly associated with MIT. In the preface, the authors emphasized that “the treatment is mathematically quantitative as well as qualitatively descriptive”; chemical engineers, they said, should themselves design the industrial apparatus they need, rather than building it first and relying on trial and error to make it work (Lewis, et al., 1923, p. v).

Writing in 1953, Lewis acknowledged the considerable achievement of Davis’s Handbook, but noted that “his quantitative treatment of operations was limited by lack of data” (Lewis, 1953, p. 699). This was not a criticism; simply to calculate the heat lost by a fluid flowing through a pipe required a considerable amount of experimental data. Aware of the importance of chemical engineering data, Lewis was an advocate of the undergraduate thesis, which trained MIT students to produce valuable empirical data that could be rapidly diffused to professional engineers and consultants. Much of the utility of the Principles lay in the useful data that it contained. E.I. du Pont de Nemours & Company (DuPont), recognizing the need for chemical engineering data, began a program of fundamental research in 1927, and in 1934 John H. Perry issued the first edition of the Chemical Engineer’s Handbook, the work of sixty contributors.

Warren K. Lewis’s teaching style was idiosyncratic, but among his papers are numerous affectionate testimonies to its effectiveness from grateful former students. Furthermore, a remarkable number of his students became eminent chemical engineers. Three of them were eventual heads of MIT’s department of chemical engineering. In the classroom, Lewis could be merciless when faced with a student who came badly prepared; nevertheless, a collection of anecdotes about himself and stories that he told his students was published by them under the title A Dollar to a Doughnut (1953)—a bet that he often made (and sometimes lost) in scientific disputes with students.

Continuous Distillation . In 1911 the two largest refiners of petroleum were the Standard Oil Company of Indiana, later Amoco and part of British Petroleum from 1998, and the Standard Oil Company of New Jersey, or Esso, later part of ExxonMobil. (Hereafter, these firms are referred to as Amoco and Esso, respectively.) Natural petroleum was separated into various fractions by distillation in the later decades of the nineteenth century, when the greatest demand was for kerosene for lighting. Batches were heated and the lightest hydrocarbons were vaporized first and then were condensed by passing them through cooled tubes. Eventually, gasoline became the most important product. Higher boiling fractions could be transformed into lower boiling fractions, such as gasoline, by a process called cracking. Amoco had the larger research group and developed a thermal cracking process, using heat to break large molecules (heavier oils or tars) into smaller ones, thereby increasing the yield of gasoline, for which a post-1918 boom was accurately predicted.

Distillation and cracking dominate oil refining. Early in the twentieth century, Lewis worked at MIT on the theory of continuous distillation (extending the work of Ernest Sorel in France in the 1890s) in order to make precision distillation a continuous and automatic process. Lewis first realized that industrial practice was well behind his own and his university colleagues’ understanding of the distillation of multicomponent mixtures such as petroleum when an MIT colleague visited a refinery. In the late nineteenth century and the early decades of the twentieth century, chemical engineers developed the theory of fractional distillation in terms of multiple stages, and it was found that multistage distillation could be achieved with a fractionating column in which there was a series of perforated plates: vapor bubbled up through the column from plate to plate and liquid flowed down. With experience and more theoretical study, material to be distilled was fed in part way up the column and part of the vapor leaving the top was condensed and returned to the column as reflux, improving the separation of the components of the feed. Different fractions of product could be withdrawn from different points in the column. Lewis and his colleague (and former doctoral student) Edwin R. Gilliland acquired international reputations in this field.

Esso lacked a development facility but soon hired an engineer from its competitor, Amoco; realizing that patent protection of any new methods would be vital, Esso also hired Amoco’s patent attorney, Frank A. Howard. In 1919 Esso created a new Development Department, headed by Howard, who immediately engaged Lewis, the best consultant he could find—by then, Lewis had a strong record with the Goodyear Tire and Rubber Company and the Humble Oil and Refining Company. From 1914 to 1927, Esso’s gasoline yield doubled to 36 percent of the crude oil input, partly through Lewis’s efforts. Howard now made contact with the German chemicals giant I. G. Farben, initiating agreements that gave Esso access to Farben’s work on coal hydrogenation. He hoped that the technical information would improve gasoline yields and increase Esso’s activities in chemicals. Howard realized that Esso would need a new research group and asked Lewis for advice; Lewis recommended hiring Robert Haslam, head of MIT’s School of Engineering Practice.

Haslam set up a team of fifteen researchers (all MIT faculty members and graduates) in Baton Rouge, Louisiana. By applying German know-how to oil refining, American petrochemical firms closed the gap between industrial practice and university and industrial research. From 1935 Gilliland (who was the fourth author of the third edition of the Principles of Chemical Engineering[1937]) took on Lewis’s role of consultant to the Baton Rouge group. Lewis, however, had been pivotal: it was he who focused chemical engineering on the design of continuous automated processing, leading to enormous growth in the world petrochemical industry. Lewis showed that university professors with hands-on industrial experience were good teachers of chemical engineering at MIT, and their Chemical Engineering Department enjoyed high worldwide prestige during the 1920s and 1930s.

Fluidized-Bed Catalytic Cracking . Petroleum contains a complex mixture of molecules, ranging from the light gases (one to four carbon atoms), through gasoline (five to ten carbon atoms) and lubricating oils (twenty to fifty carbon atoms), to heavy bituminous residues whose molecules contain more than seventy carbon atoms. Cracking transformed the heavy fractions into more valuable lighter ones. A short two-and-a-half page memorandum in the MIT archives, written by Lewis probably in the 1930s, is typical of his scientific approach to new problems. He listed eleven points that he had deduced from his experience of cracking. For example, he learned that the stability of a hydrocarbon decreases in any series as the molecular weight increases and that the C-H bond is the most stable; therefore, it is the C-C bonds that tend to break. Thermal cracking produced sixty to seventy octane gasoline, which required a tetraethyl lead additive to boost the octane number and so prevent gasoline engine pre-ignition. By 1930, however, the French engineer Eugène Houdry had invented a method of producing high-octane fuel by cracking heavy tars using a silica-alumina catalyst. Houdry succeeded in selling the process in the United States to the Sun Oil Company, which worked on its development with Socony-Vacuum; half a dozen plants were in operation in the early 1940s. Lewis was consulted about catalytic cracking by Esso, and serious work began at the Baton Rouge research center in 1936.

The catalyst was quickly poisoned by carbon deposits. This was at first overcome by using two separate beds of catalyst: the vaporized petroleum was passed (at high temperature and pressure) through the first catalyst bed and after a predetermined time, the petroleum stream was automatically switched to a second bed, while the first bed was regenerated with an air blast; the process, however, was complex and costly. Small-scale experiments at MIT showed that gasoline could be successfully produced if powdered catalyst were mixed with petroleum vapor and passed under pressure through a hot pipe. Lewis and Gilliland’s innovation was the fluidized catalyst bed: Particles of catalyst were suspended in the flowing petroleum vapor, giving time for the chemical reactions to take place; with the fluidized catalyst in suspension, it was easier to automate the process, passing the catalyst rapidly between a reaction zone and a regeneration zone. Lewis’s design was in operation in 1940; the first plant cost $4.5 million and processed 13,300 barrels of oil per day. Soon, the production of American high-octane aviation fuel was increased a hundredfold and quantities were shipped to Europe, helping the Allied effort in World War II. By 1962 there were 222 fluidized-bed catalytic crackers worldwide.

Polymers: The Manhattan Project . In 1929, after nine years in the post, Lewis resigned his chairmanship of the MIT Chemical Engineering Department to concentrate on research and teaching; he was nearly forty-eight years old. However, his interests continued to expand with scientific developments, and in 1942 he published Industrial Chemistry of Colloidal and Amorphous Materials, with coauthors Lombard Squires of DuPont and Geoffrey Broughton of Eastman Kodak. The book, reprinted twice that year, included discussions of the newly synthesized polymers (such as polyester and nylon fibers, polystyrene, and the rubberlike polyisobutylene) as well as the commercially important natural polymers: wool, cotton, and silk. The illustrations included the kind of x-ray diffraction photographs of fibers that were important in establishing the structure of large organic molecules such as DNA a decade later. Lewis and his coauthors used basic science to explain large-scale phenomena in terms of the forces between atoms and molecules. In the 1930s and 1940s, this was a new approach to engineering, and the term engineering science was soon current. Lewis noted that polymer chemistry had developed to the point that “industry [could] produce materials of almost any required physical characteristics” (Lewis, et al., 1942, p. 469).

In 1941 Lewis was asked in his capacity as a leading consultant in the process industries to join a National Academy of Sciences committee to review existing atom bomb research; the Manhattan project received presidential approval later that year. From September 1942, the project was managed by General Leslie R. Groves, a senior army engineer. Groves appointed a review committee under Lewis’s chairmanship to monitor progress and priorities; the other committee members were the ordnance design engineer E. L. Rose, the Harvard physics professor John H. Van Vleck, and the physicist Richard C. Tolman (a former high-school friend of Lewis). Lewis and his committee traveled constantly during World War II among the various Manhattan research laboratories and development sites, including Berkeley, Clinton, Hanford, Los Alamos, and the naval research laboratory in Washington, D.C. The Lewis committee approved the nuclear physics research program proposed by J. Robert Oppenheimer and his staff, and they recommended that work on a thermonuclear bomb should have lower priority than the atomic bomb. Lewis was among the select group invited to witness the first self-sustaining nuclear chain reaction on 2 December 1942 in Chicago; then sixty years old, Lewis at the last minute generously gave up his place to a younger man (probably Edwin Gilliland). The successful production of the atomic bomb irrevocably changed the world: all-out war would in the future be either unthinkable or suicidal. Later, Lewis hardly ever talked about the Manhattan Project, although he was haunted by it; he had believed that it was necessary to build the bomb, but in his very old age he “worried that he could not wash the radiation off his hands” (Williams, 2002, p. 6).

Social Responsibility of Engineers . A year after the Hiroshima bomb, MIT vice president James R. Killian Jr., in a mood of postwar reevaluation, suggested to the MIT president, Karl Compton, that a committee of the faculty be convened to study educational objectives, organization, and operations at the institute. Some fundamental questions needed answers. For example, were courses too theoretical? Was there enough time for humanistic studies? Killian suggested that Lewis was the logical person to chair the committee, in view of “his great prestige and his strong interest in teaching” (Williams, 2002, p. 67). The Report of the Committee on Educational Survey, known as the Lewis Report, was published in December 1949; Lewis was sixty-seven and had retired the previous year.

The nub of the Report lay in chapter 3, “A Broader Educational Mission.” Acknowledging the increasing complexity of society, it stated that science and technology could not be separated from their human and social consequences, that the postwar generation’s most difficult and complicated problems lay in the humanities and the social sciences, and that these problems reflected the impact of science and technology on society. MIT now had the opportunity to make a larger contribution to solving social problems and to giving scientists and engineers a better understanding of the forces at work in society. Conversely, the school could also give social science and humanities students a deeper understanding of the implications of science and technology. After the publication of the Lewis Report, the School of Humanities and Social Sciences was added to MIT’s three existing schools (Engineering, Science, and Architecture and Planning). The Lewis Committee believed that MIT was in a position to make contributions “to education and the advancement of knowledge” in all four spheres (Lewis, et al., 1949b, pp. 42–43).

Lewis wrote and spoke about the role of the engineer in society. Not infrequently, he made the point that found its way into the Lewis Report, namely, that the most difficult problems were not those of engineering and the exact sciences, but those of sociology, economics, and political science. In articles by Lewis published in the 1940s and 1950s, he identified the essential product of engineering: the huge increase in human efficiency. Lewis recalled his job in a tannery in New Hampshire about fifty years earlier, when the working week was seventy-eight hours; by the 1950s it was down to forty hours and the standard of living of the worker had more than doubled. In the 1850s, fewer than 5 percent of children attended high school, whereas in the 1950s the figure was 85 percent. And yet, Lewis noted, the operators of the machinery that produced unprecedented wealth and leisure were often less happy than the subsistence workers of the past. Lewis’s point was that engineers who failed to attend to the social consequences of technological developments were not members of a profession, but mere technicians who were uninformed about the social, economic, political, and international environment.

Lewis was fond of defining the engineer as “someone who can do for a dollar what any damn fool can do for two” (Williams, 2002, p. 30). He had faith in the utility of science and engineering and believed them to be the agents for social progress. Engineering students, virtually all men, many of them (even as late as the 1960s) from the poorer and less-well-educated segments of the middle class, were able to obtain a professional degree in four years. Such students had a strong belief in meritocracy and accepted capitalist society. Lewis too was a staunch believer in the profit system as an objective measure in a competitive capitalist economy of the success of an enterprise and its economic contribution to the community, but he despised the profit motive—undertaking an enterprise with the sole purpose of making a profit. The irony for Lewis was that his own profession, chemical engineering, helped fuel the automobile age and later supplied the antibiotics required to support factory farming, so that it was instrumental in destroying his childhood way of life on a farm near a small town (Williams, 2002, p. 12).

BIBLIOGRAPHY

There is a great deal of unpublished, uncataloged archival material pertaining to Warren K. Lewis at MIT. Most of it resides in the MIT archives (building 14). The author of this article was informed that the majority of the papers were classified, presumably because of Lewis’s wartime association with the Manhattan Project; no one had asked for them to be declassified. At the opposite side of the campus is located the MIT Museum (building 52), which holds fewer papers—again uncataloged. Professor Rosalind H. Williams (Lewis’s granddaughter) is a senior faculty member at MIT and has a quantity of papers, though many have been handed over to MIT. Although this author knows of no single exhaustive bibliographic list, a combination of the one for this article and Hottel’s would be fairly comprehensive.

WORKS BY LEWIS

“The Theory of Fractional Distillation.” Industrial and Engineering Chemistry 1 (1909): 522–533.

With William H. Walker. “A Laboratory Course of Chemical Engineering.” Journal of the American Chemical Society 33 (January–June 1911): 618–624.

With Frank Hall Thorp. Outlines of Industrial Chemistry: A Text-Book for Students. 3rd ed. New York: MacMillan, 1916.

With William H. Walker and William H. McAdams. Principles of Chemical Engineering. New York: McGraw-Hill, 1923.

With Lombard Squires and Geoffrey Broughton. Industrial Chemistry of Colloidal and Amorphous Materials. New York: Macmillan, 1942.

“The Professional Responsibilities of the Technical Man.” Chemist (June 1949a): 205–211. This was Lewis’s acceptance address on the occasion of his receipt of the American Institute of Chemists Gold Medal, 7 May 1949, in Chicago.

With John F. Loofborouw, Ronald H. Robnett, C. Richard Soderberg, et al. Report of the Committee on Educational Survey to the Faculty of Massachusetts Institute of Technology, Cambridge, MA: Technology Press, 1949b. Copies are in the MIT Museum.

“Chemical Engineering—A New Science.” In Centennial of Engineering, 1852–1952, edited by Lenox R. Lohr. Chicago: Museum of Science and Industry, 1953.

“The Future of Engineering as a Profession.” Technology Review 59, no. 7 (May 1957): 351–354.

“Evolution of the Unit Operations.” Chemical Engineering Progress Symposium Series 55, no. 26 (1959): 1–8.

OTHER SOURCES

Brigham, W. E. “We Were Ready.…” Boston Evening Transcript, 11 January 1919.

Cohen, Clive. “The Early History of Chemical Engineering: A Reassessment.” British Journal for the History of Science 29 (1996): 171–194.

A Dollar to a Doughnut, or Doc Lewis, as Remembered by His Former Students. New York: American Institute of Chemical Engineers, 1953.

Furter, William F., ed. History of Chemical Engineering. Washington, DC: American Chemical Society, 1980.

Hottel, Hoyt C. “Warren Kendall Lewis, August 21, 1882–March 9, 1975.” Biographical Memoirs of the National Academy of Science (U.S.A.) 70 (1996): 204–218. Also available from http://stills.nap.edu/html/biomems/wlewis.html.

Hounshell, David A., and John Kenly Smith. Science and Corporate Strategy: DuPont R&D, 1902–1980. Cambridge, U.K.; New York: Cambridge University Press, 1988.

Landau, Ralph. “Academic–Industrial Interaction in the Early Development of Chemical Engineering at MIT.” Advances in Chemical Engineering 16 (1991): 41–49.

Landau, Ralph, and Nathan Rosenberg. “Successful Commercialization in the Chemical Process Industries.” In Technology and the Wealth of Nations, edited by Nathan Rosenberg, Ralph Landau, and David C. Mowery. Stanford, CA: Stanford University Press, 1992.

Mattill, John. The Flagship: MIT School of Chemical Engineering Practice 1916–91. Cambridge, MA: MIT Press, 1991.

Peppas, Nicholas A. One Hundred Years of Chemical Engineering. Boston, and Dordrecht, Netherlands: Kluwer Academic Publishers, 1989.

Perry, John H., ed. Chemical Engineer’s Handbook. New York and London: McGraw-Hill, 1934.

Rhodes, Richard, The Making of the Atom Bomb. New York: Simon & Schuster, 1986.

Servos, John W. “The Industrial Relations of Science: Chemical Engineering at MIT, 1900–1939.” ISIS 71 (1980): 531–549.

Spitz, Peter H. Petrochemicals: The Rise of an Industry. New York: Wiley, 1988.

Weber, Herman C. The Improbable Achievement: Chemical Engineering at MIT. Washington, DC: American Chemical Society, 1980.

Williams, Rosalind H. Retooling: A Historian Confronts Technological Change. Cambridge, MA: MIT Press, 2002. Williams is Lewis’s granddaughter.

Clive Cohen