2—
The Roaring Twenties
The increased reputation of physical science after the war combined with the requirements and fruits of California's high technology to give physics at both Caltech and Berkeley a more rapid acceleration during the 1920s than it experienced at any other research university in the country. The most prominent single theme in this California physics was its concern with high voltages and radio technologies. The theme sounded first at Caltech. In 1920 Southern California Edison provided the new institution's new president, Millikan of the NRC, with a high-tension testing laboratory. The utility's interest is easily stated: according to a rule of the art, to transmit power economically, at least 1,000 volts should be provided for each mile to be traversed.[35] Southern California Edison, then becoming the world's largest producer of hydroelectric power at a cost that exceeded the price of the Panama Canal, aimed to work at over 200,000 volts. The laboratory at Caltech did improve the technique of high-voltage transmission. Later it supplied the power to run a powerful x-ray
[33] Quotes from, resp., Weld, Science, 52 (1920), 46, and Carty, NRC, Reprint , no. 8 (1919), 8; Hale likewise lamented the "avalanche of new students," "these swelling throngs," in Harper's, 156 (1928), 247. Cf. Kellogg, Science, 54 (1921), 19, 22; Angell, NRC, Reprint , no. 6 (1919), 2; H. Hoover, ibid., no. 6 (1925), 4.
[34] National Resources Committee, Research, 1 (1938), 177; Weart in Reingold, Context , 298–9; Geiger, Knowledge , 262.
[35] Compton, Science, 78 (1933), 21.
plant for cancer therapy designed by Charles Christian Lauritsen, an engineer and physicist who for a time competed successfully with Lawrence in smashing atoms.[36] At Berkeley the high men in voltage were Fuller, who had become professor there without cutting his ties to Federal, and his protégé Ernest Lawrence.
The work of such men and the students they attracted paid dividends on the capital the state had invested in physical science. The president of the American Physical Society alerted its members in 1933 to the distortion of the old ring circle of Eastern institutions worked by the newly scientific West. "In the past decade the State of California has risen from obscurity to become a center in the physical circle, or more precisely one of the two foci in the academic ellipse representing American physics."[37] Europeans also noticed. "The development of science in California is very impressive, even if theoretical physics is not so strongly represented." Hendrik Kramers, professor of physics at the University of Utrecht, teaching in Berkeley in 1931, thus informed the dean of the world's quantum theorists, Niels Bohr of Copenhagen, who would visit the state twice himself in the 1930s to see its physics for himself.[38]
The MIT of the South
Bohr's visits fit a pattern established in the 1920s by the new administration of Caltech, Hale and its "executive head," Millikan, who had the power, but not the duties, of a college president. With plenty of money from local sources and the Rockefeller and Carnegie foundations, Caltech brought in the leaders of international physics for seminars and lecture courses: Max Born, Paul Ehrenfest, Albert Einstein, H.A. Lorentz, A.A. Michelson, Wolf-gang Pauli, C.V.R. Raman, Arnold Sommerfeld. With the help of the prestige thus conferred, the former Throop College of Technology recruited first-rate scientists at home and abroad: Ira Bowen, Paul Epstein, William Houston, J.R. Oppenheimer, Linus Pauling, Richard Tolman, Fritz Zwicky. The great luminaries and Nobel
[36] Sorenson, Jl. elect., 53 (1924), 242–5; Lauritsen and Bennett, PR, 32 (1928), 850–7; Holbrouw, in Weart and Phillips, History , 86–93.
[37] Foote, RSI, 5 (1934), 65.
[38] Kramers to Bohr, 5 Oct 1931 (BSC).
prize winners, among whom Millikan, already widely nominated, would soon be enrolled, attracted hundreds to pay thousands to belong to the Caltech Associates, a fund-raising initiative worthy of Wall Street.[39] By 1930, by most measures, Caltech overshadowed MIT as a technical school and rivaled the University of California in most fields not related to the social sciences.
Caltech's trustees cared less for science, natural or social, than for the practical and electrical potential of the school. Delays in construction occasioned by the first world war had caused an acute shortage of power in the fast-growing Los Angeles basin. In 1920 the creation of the Federal Power Commission and the revocation of an ancient prohibition against damming navigable waterways opened the way to new hydroelectric developments. Southern California Edison, which dreamed of a dam on the Colorado River to generate hydroelectric power for Los Angeles, planned in the meantime $100 million worth of construction, including conversion of its high-voltage lines to 220,000 volts.[40] These undertakings required research. A cheap and reliable way to get it was to build a high-voltage laboratory at Caltech, supply it with electricity, lease it to the school at a nominal fee, and obtain from its high-powered, low-paid staff help with "all problems of the company arising in connection with [its] experimental and research work."[41]
Millikan understood how to couple a scientific program to the applied work of the laboratory. In a successful approach to the Carnegie Corporation, he wrote that "the most promising field of science today is the field of the behavior of matter under enormously high potentials. . . . The physicist wishes to enter it for purely scientific reasons." Millikan proposed studying spark spectra in high vacua, high-potential x rays, and corona discharges at high potentials. Ultimately the knowledge gained might help in the understanding of nature's play at extremes of electric force, temperature, and pressure, in atoms and in the stars.[42]
[39] Seidel, Physics research , 66–83; Kargon, Rise , 101–3.
[40] Rendy, Jl. elect., 44 (1919), 479–81; Breckenridge, ibid., 501–5, and 45 (1920), 347; Barre, ibid., 566–7.
[41] Arthur Fleming to Hale, 17 Mar 1911, enclosing lease, quote (Hale P, micro edn, 14.72–4). The company pledged $100,000 for the building and 10,000 kWh a month to run it.
[42] "Memorandum . . . to the Carnegie Corporation," 1921 (Hale P, micro edn,6/406–7); Seidel, Physics research , 321; Kargon, Rise , 122–35.
The early work of the high-voltage laboratory centered on immediate application. Royal Sorenson, a Caltech electrical engineer and consultant to Southern California Edison and the Metropolitan Water District of Los Angeles, built a four-stage cascade transformer that gave a million volts. It was used to test vacuum switches that Sorenson and Millikan designed to overcome the arcing in oil circuit breakers. A high-voltage switch, patented per agreement as the joint property of Southern California Edison and Caltech, was sold to GE in 1930 for $100,000, which repaid the cost of the laboratory. Other patented products of the laboratory included high-voltage fuses and discharge tubes.[43] The physics on which they rested was worked out by Millikan and Lauritsen, a graduate student and former employee of the Federal Telegraph Company, and by Oppenheimer, who came to Caltech as a National Research Fellow in 1928.[44]
Lauritsen carried Caltech's high-voltage technology into new fields with the help of R.D. Bennett, likewise a National Research Fellow, who had sought to extend work on the quantum theory of x-ray scattering to high voltages. The internal workings of the very sturdy instrument Lauritsen devised relate to particle accelerators and will be discussed later. Its external workings were more general and immediate. Millikan had asked Seeley G. Mudd, a Pasadena cardiologist, for money to develop Lauritsen's tube. Mudd consulted Francis Carter Wood of the Crocker Institute for Cancer Research at Columbia, who advised that the high-voltage x-ray tube was "the exact step forward that we need for the treatment of cancer." Others disagreed, for example, Fred Stewart of New York's Memorial Hospital, who preferred "small quantities of energy over a long period of time." Millikan accepted the advice that favored the tube.
Preliminary therapy began in 1930 at 600,000 volts, which Wood judged to be insufficient. Higher potential meant more money. Millikan got it from W.K. Kellogg, the Corn Flakes King, who desired only "credit of some sort."[45] While Caltech built the
[43] Sorenson, AIEE, Trans., 45 (1926), 1102–5; Caltech, Board of Trustees, minutes, 25 Feb 1930 (E.C. Barrett P, 1/8); U.S. patents 1,757,397 and 1,764,273.
[44] Millikan and Lauritsen, NAS, Proc., 14 (1928), 45–9; Oppenheimer, ibid., 363–5.
[45] Wood to Mudd, 22 Sep 1930, and Stewart to Mudd, 1 Jan 1931 (MillikanP); Holbrouw, in Weart and Phillips, History , 86–93.
Kellogg Radiation Laboratory, Los Angeles County Hospital used its 600-kV tube to treat 200 patients. They improved. Albert Soiland, the radiologist in charge, ascribed the efficacy of the rays to their energy, or perhaps to their homogeneity.[46] It does not appear that many of the 746 people treated at the Kellogg Laboratory during the 1940s improved dramatically. The sanguine and bold attributed the fault to the voltages. Still higher energies were sought at Berkeley, Stanford, and Caltech. Supervoltage x rays proved no better therapeutically than high-voltage ones. But the attempt to devise equipment to make them and the funding their uncertain promise provided were very good for physics.
The Harvard of the West
Wartime service also advanced research at Caltech's northern rival. An immediate outcome of Berkeley's contribution to national defense, and a harbinger of much greater reform, was the transmutation of a parochial editorial committee charged with publishing their colleagues' contributions to knowledge into an outward-looking Board of Research. In the early 1920s the new board brought the experience it had gained in supervising war work to promoting the cause of research, particularly scientific research, to the University's administration and well-wishers. The board's pushiness fit in well with a general agitation, led by G.N. Lewis, John C. Merriam (chairman of the wartime State Committee on Scientific Research and a high official of the NRC), and Armin O. Leuschner (dean of the Graduate School and head of the NRC's Physical Sciences Section in 1918), to improve salaries and working conditions. The professors won important concessions in self-governance and a new president representative of their new self-image. He was William Wallace Campbell, a research astronomer, formerly head of Mount Wilson's northern rival, the University's Lick Observatory.[47] Under its version of George Ellery Hale, Berkeley rapidly expanded its facilities and staff for physical research.
[46] Soiland, Radiology, 20 (1933), 99–104.
[47] U.C., Pres. rep. , 1919/20, 156–8; Seidel, Physics research , 85–105.
First things first. The throng of students entering the University after the war included many more would-be engineers and physicists than could be taught in the old headquarters of physics in South Hall. In 1924 Le Conte Hall, the greatest achievement of the chairman of the Physics Department, E. Percival Lewis, opened for business (plate 1.3). It was among the largest physics buildings in the world, and second in size only to those at Cornell, Illinois, and Princeton (all built under uninflated prewar conditions) in the United States. It exceeded its larger counterparts in the proportion of space dedicated to individual research—forty rooms in Berkeley in contrast with twenty-eight rooms at Princeton.[48] The Board of Research willingly helped to furnish Le Conte. The physicists there had the good sense, in the board's opinion, to spend their money on equipment and supplies, "in marked contrast to . . . other departments, which expend the funds granted almost exclusively for personal research assistance."[49] The board's grant to the Department in 1923, in anticipation of the completion of Le Conte, was $5,000. The amount rose to $10,000 in 1925/26 and $12,250 in 1928/29 before sinking to an average of about $8,000 during the Depression. These grants and outside monies built up an inventory of research equipment valued at $226,500 in 1934, exclusive of the special apparatus in Lawrence's Radiation Laboratory.[50] The Department's operating expenses also increased steeply, reflecting the enlargement of the staff by the capture of several young physicists: from $78,000 in 1922/23, just before Le Conte opened, to $100,000 in 1923/24 and 1924/25, to $130,000 in 1929/30.[51]
Berkeley tried first to fill its physics building with men of established reputation: Niels Bohr, Arthur Compton, Paul Epstein,
[48] U.C. Pres. rep. , 1918/19, 43, 81; Forman, Heilbron, and Weart, HSPS, 5 (1975), table D.1. Le Conte's floor space covered about 5,200 square meters; Simpson, California monthly, 16:5 (1924), 251–3, and "Le Conte Hall" (TBL, CU/68).
[49] L. Loeb to R.G. Sproul, 8 Nov 1927 (Loeb P); Board of Research, "Minutes," 1928 (TBL).
[50] Ibid., 9 Sep, 4, 15, 20 Oct 1923, 4 Apr and 14 Oct 1925 (TBL, CU/9.1); "Research budgets, 1924–1927," and R.T. Birge to Sproul, 4 Aug 1934 (TBL, CU/68).
[51] U.C., Pres. rep. , 1925/26, 559; 1926/27, 597; 1927/28, 671; 1928/30, 866; Birge, History, 2 , vii, 15; viii, 46.
W.F.G. Swann, none of whom valued the charms of Le Conte above the attractions of his position elsewhere. When this premature strategy, which was urged by G.N. Lewis and the Board of Research, failed, two ambitious recent recruits to the Department, Raymond T. Birge, who became its chairman in 1932, and Leonard B. Loeb, took over the head-hunting. Their strategy, as Birge later summarized it, was to follow the guidance of the NRC: "In order to guarantee a prospective candidate's scientific standing and research ability, we have chosen from among the most successful of the National Research Fellows." In this way they chose, among others, Samuel Allison, Frederick Brackett, Robert Brode, Francis Jenkins, E.O. Lawrence, J. Robert Oppenheimer, and Harvey White.[52]
Recruitment is one thing, retention another. Campbell understood the danger: "Tempting invitations come every year to half a dozen or more members of our faculties—always to men in the front rank of attainment and promise—to leave our employ and cast in their lot with other universities, at higher salaries than they are here receiving. . . . The competition for able professors is already keen; it is going to be more keen in the near future; and we must find ways and means of retaining the services of our able men." Campbell tried to make good his word. Birge wrote a colleague at Harvard in 1927: "When our own men, at least the younger men, have had definite offers elsewhere, the administration has at least done something to hold them, and we have succeeded in holding them so far."[53] Allison and Brackett left before 1930, Oppenheimer in 1946; the others remained, despite flattering invitations to emigrate. Loeb refused the chairmanship of Brown University's physics department in 1928, and Brode, Lawrence, and (until 1946) Oppenheimer frequently turned down raiders. In consequence their salaries rose, Oppenheimer's marginally (he was a theorist, a wealthy man, and a part-time professor at Caltech), Brode's by 50 percent in six years (from $2,700 in 1927/28 to $4,160 in 1933/34), Lawrence's by almost 150 percent in eight years (from $3,300 in 1928/29 to $8,000 in 1936/37).[54] As
[52] Birge, "Budget request," 1935, in U.C. Budget Requests (TBL). For recruitment strategies, failures, and successes, see Seidel, Physics research , 85–105.
[53] U.C., Pres. rep. , 1926/28, 5–6; Birge to Kemble, 27 Oct 1927 (AHQP).
[54] U.C. Budget Request, 1934/35 (TBL); Sproul to Lawrence, 11 Apr 1928, 19Sep 1930 (full professor at $4,500), and 4 Mar 1936 (16/42).
the figures suggest, Lawrence was hard to get and expensive to keep.
Lion Hunting
Loeb began stalking Lawrence in 1926. The game was then a National Research Fellow at Yale, where he had arrived in the intricate wake of his teacher W.F.G. Swann, whom Berkeley wooed in vain. Lawrence, a native of South Dakota and a graduate of its state university, had sought out Swann in 1922, on the recommendation of Merle Tuve, likewise from South Dakota, whom Lawrence had known from childhood. (It is singular that Tuve and Lawrence came from similar middle-class backgrounds of Scandinavian origin, had similar training in physics, and later went at atom smashing with instruments similar in cost and size.) Lawrence joined Swann and Tuve at the University of Minnesota to work on a master's degree. In 1923 Swann left Minnesota for the University of Chicago, where Lawrence followed, to begin work on the photoeffect in potassium vapor. He made good progress in designing equipment before Swann wandered to Yale. There Lawrence finished his dissertation and took up another investigation, which also posed delicate instrumental problems, for example, the creation of a monochromatic beam of slow electrons.[55] That project acquainted him with the magnetic analysis of particle streams, which may later have assisted his design of the cyclotron.
As a National Research Fellow at Yale, Lawrence extended his work on the photoeffect to other alkali vapors and used his monochromatic electrons to demonstrate that the excitation function for ionization of an alkali vapor—the dependence of the probability of ionization on the energy of the ionizing agent—was the same for electrons as for x rays. This demonstration attracted Loeb, head-hunting at the American Physical Society's meeting of May 1926. He spoke with the demonstrator, and wrote his chairman: "I felt out one of the most brilliant experimental young men in the East—a lad whose name is on everyone's lips on account of his recent papers on Ionizing Potentials. . . . He is personally one of the
[55] Childs, Genius , 63–75; Lawrence, NAS, Proc., 12 (1926), 29–31.
most charming men I have met. . . . When asked whether he would consider an Assistant Prof. at Berkeley following the termination of his fellowship, he was quite enthusiastic." Birge too praised Lawrence's "really splendid experimental work" on the excitation functions.[56]
Two projects were never enough for Lawrence. A fellow midwesterner, Jesse Beams, who had settled at the University of Virginia, had tried to measure the interval between the absorption of a quantum and the ejection of a photoelectron. While failing, he had devised a very fast electric switch incorporating two Kerr cells. (A Kerr cell is a parallel-plate condenser with a gaseous or liquid dielectric.) Beams and Lawrence teamed up to try to study the speed of the onset of birefringence and to incorporate Beams's idea into a practical device for creating very short bursts of light.[57] Lawrence was to stick to the Kerr effect, as he did to photoionization, until the cyclotron turned his attention to bigger things; and he was to stay in productive contact with Beams while the idea of the cyclotron developed.
Berkeley made its first offer to the young electro-optician in the spring of 1927; Yale did the same; Lawrence stayed East (plate 1.4). His rejection of Berkeley would have discouraged men of weaker will than Birge and Loeb: "I like Yale, the personnel, the laboratory and the facilities for research perhaps even as much as I like the friends I have acquired in New Haven." Loeb and Birge persisted. They extolled Berkeley's "democratic spirit," research ethic, and, what the NRC campaigned for and every ambitious academic desired, light teaching load. Lawrence allowed that if Yale made him work too hard, he might go West: "I am more interested in finding some more of Mother Nature's secrets than telling to someone else things I already know about her." The announcement by his flighty mentor, Swann, of a new nest, the Bartol Foundation in Philadelphia, "a hard blow to Yale and to me," increased Lawrence's mobility.[58]
[56] Lawrence, Science, 64 (6 Aug 1926), 142; Loeb to Hall, in Childs, Genius , 99; Birge to Lawrence, 9 June 1926 (Birge P).
[57] Beams and Lawrence, NAS, Proc., 13 (Jul 1927), 505–10, and JFI, 206 (1928), 169–79; Szlvessy, Handbuch der Physik, 21 (1929), 742–3.
[58] Quotes from, resp., Lawrence to Loeb, 13 Apr 1927 (Loeb P); Birge to Lawrence, 23 Feb 1928 (2/32); and Lawrence to Loeb, 7 May 1927 (Loeb P). Cf. Lawrence to Tuve, 30 Sep 1926 (MAT, 4): "Merle, for the nth time, I hope youwill run up to New Haven . . . This is a wonderful lab."
Loeb now hinted that Berkeley might offer an associate professorship with unusually few teaching responsibilities. Yale countered by improving Lawrence's laboratory and reducing his courses.[59] Friends of California were commissioned to enlighten Lawrence. They reported that he believed that at Berkeley only full professors could supervise graduate students (a regime to which he could not submit) and that he had no conception of the treasures of Le Conte Hall. Loeb and Birge set him right in February 1928, when Berkeley formally offered Lawrence an associate professorship. They itemized the research staff, budget, and facilities, pointed to auxiliaries in the Chemistry Department, praised the liberality of the Physics Department in assigning graduate students to junior faculty, and fired off their biggest gun: "The teaching schedules are as light as at any place in the country, with the exception of Harvard."[60] There remained only salary. The very experienced Swann advised Lawrence to ignore the few hundred dollars difference between Berkeley's offer and Yale's, which the lower cost of living in California would cancel, and to concentrate on the research opportunities. Birge reassured the captured lion that promotion came rapidly to vigorous young research men. It was as if the University had been preparing itself ever since the war for the reception of Ernest Lawrence: "Younger men are now being appointed and advanced on an entirely different plane from that of the older men. . . . I doubt if any man has ever been offered the permanent position of associate professor at this University with as short a period of teaching and research experience as in your case. . . . The conduct of this University now is really in the hands of the exact scientists."[61]
Lawrence arrived in Berkeley in the summer of 1928. By September he was writing with such fervor about his new surroundings that Beams rated him "a 'Native Son' of California already."
[59] Loeb to Lawrence, 20 May 1927, and Lawrence to Loeb, 27 Sep 1927 (Loeb P).
[60] E.U. Condon, "Comments on Birge's History" (UCA); Muriel Ashley to Loeb, 18 Feb 1928 (Loeb P); E. Hall to Lawrence, 21 Feb 1928 (the offer) (8/8); Loeb to Lawrence, with passages to Birge, 21 Feb 1928 (Loeb P).
[61] Birge to Lawrence, 23 Feb 1928, and reply, 2 Mar 1928, in Birge, History, 3 , ix, 5–9; Swann to Lawrence, 28 Feb 1928 (17/3); Birge to Lawrence, 5 Mar 1928 (2/32), quote.
The enthusiast took up residence at the Faculty Club, where Gilbert Lewis brokered influence and crossed disciplines nightly at the dinner table.[62] Lewis became a strong supporter of Lawrence's and, after the invention of the cyclotron, a transient, but most influential, collaborator. The antecedents of the grand invention are not to be sought, however, in the research work that Lawrence did between dinners with Lewis. He continued his study of the photoeffect in alkali vapors.[63] What counted more for his future were his sojurns at General Electric's research laboratories in Schenectady during the summers of 1929 and 1930.
In arranging for his visit of 1929, Lawrence wrote A.W. Hull, an expert on x rays and vacuum tubes who would be his host, that he wanted to study the photoeffect and the Kerr cell. Nothing new there. But Hull was then working with Beams on a lightning arrestor and on the development of sparks under high voltages, and Lawrence was drawn into the investigation.[64] Here he faced for the first time the practical difficulty of holding a potential of more than half a million volts. If we credit Beams's unlikely recollection, this experience inspired a line of thought remarkably, indeed astonishingly, close to the reasoning behind Lawrence's great invention. "There's just no use trying to build this [voltage] up," Lawrence argued. "You may get a few million volts. That's limited. What we've got to do is to devise some method of accelerating through a small voltage, repeating it over and over. Multiple acceleration."[65]
In the event, Lawrence did not labor with Beams or Kerr cells or photoeffects. He wandered about GE's well-equipped laboratories, familiarized himself with Hull's state-of-the-art vacuum tubes, with high-voltage equipment, and with so much of the firm's applied research that he was offered (but declined) a consultancy. Lawrence brought this lore back to Berkeley, along with two other items of importance: a glass blower, E.H. Guyon, a specialist in x-ray and vacuum tubes; and a genius at electronics,
[62] Swann to Lawrence, 14 Sep 1928 and 7 Jan 1929, and Beams to Swann, 18 Oct 1928 (Swann P); Lachman, Borderland , 143.
[63] Lawrence to Loeb, 13 Mar, 16 and 25 May 1928 (Loeb P); Swann to Lawrence, 3 and 4 Oct 1928 (Swann P).
[64] Lawrence to Hull, 28 Mar 1928 (7/28).
[65] Beams, quoted by Childs, Genius , 142.
Hull's assistant David Sloan, whom Lawrence persuaded to improve his B.S. in physics from Washington State College with graduate work at the University of California. Sloan came in 1930, on a Coffin Fellowship (established in 1922 in memory of GE's first president, Charles A. Coffin) from GE.[66] He remained throughout the 1930s, kept from his degree by lack of interest in his studies and injury to his back. The early successes of Lawrence's Radiation Laboratory owed much to David Sloan, who would not have come to Berkeley but for Lawrence's sojurns at GE.