Bohr’s news had spread quickly, and when Leo Szilard heard about uranium fission a few days later from his friend Eugene Wigner, a physicist at Princeton, he was stunned. It was what he had been working toward for years. “When I heard,” he recalled, “I saw immediately that these fragments, being heavier than corresponds to their charge, must emit neutrons, and if enough neutrons are emitted in this fission process, then it should be, of course, possible to sustain a chain reaction. All the things which H. G. Wells predicted appeared suddenly real to me.” Szilard had immediately understood the implications of such a discovery. Europe was on the brink of another world war, and fission—which might be used to create “violent explosions”—had to be kept from the Germans. His first thought had been to contact Fermi and those physicists in Europe who were most likely to intuit this possibility and begin to organize self-imposed censorship on all nuclear research.
But once Bohr and Fermi spoke publicly about uranium fission in Washington, the cat was out of the bag. At the conference, Fermi, who had himself nearly discovered fission several years earlier, theorized that when a neutron knocked uranium apart, more neutrons might be emitted. He suggested there might be the possibility of a chain reaction—the release of atomic energy—and a bomb. In the days that followed, physicists everywhere rushed to their laboratories to test the process of uranium fission, and within forty-eight hours the key experiments had been replicated in several laboratories, including the Rad Lab, the Carnegie Institution, and Johns Hopkins. Bohr’s information was published in the Physical Review, which later reported verification by Fermi at Columbia. Following a demonstration of uranium being bombarded with neurons at the Carnegie Institution on January 28, the Washington Evening Star carried a front-page story with the banner headline “Power of New Atomic Blast Greatest Achieved on Earth.”
Throughout that spring, Bohr and Fermi continued to appear together at various scientific meetings, and their increasingly candid views on uranium fission, and its potential military use, were the talk of scientific and political circles. In mid-April, Bohr again stayed at Tuxedo Park for the weekend, where, as Loomis wrote Vannevar Bush, “he gave us a very interesting talk” on chain reactions with uranium and other heavy elements. After the American Physical Society’s spring meeting on April 29, The New York Times wrote that the conferees argued “the probability of some scientist blowing up a sizeable portion of the earth with a tiny bit of uranium.” Over the course of that summer, the intense activity and concern in the world of physics prompted the Einstein letter to Roosevelt warning him of the seriousness of atomic weapons. The whole matter came to a head in the fall of 1939 with the formation of a uranium committee, under the chairmanship of Lyman Briggs, director of the National Bureau of Standards. The Briggs Advisory Committee on Uranium was to be a panel made up of physicists and representatives of the army and navy and would coordinate secret research on a fission explosive. If a bomb was possible, and it unleashed enormous power, it would render the totalitarian war machines of Hitler and Mussolini unstoppable. It was essential that America’s scientists and military organizations stay ahead on nuclear research should it ever prove feasible to build such a device. “Shortly after that,” recalled Loomis, “the thing went underground.”
As Europe slipped deeper into the war, the uranium panel twiddled its thumbs. It was so mired in bureaucracy that by the spring of 1940, it had managed to approve only the $6,000 in research funds earmarked for Fermi and Szilard, so they could purchase uranium and graphite for their fission experiments. A number of leading scientists were increasingly alarmed by the government’s inaction, and chief among them was Vannevar Bush. During the weekend get-together in Del Monte, they had discussed the various possibilities for destruction inherent in fission. At the time, Bush had relayed the expressed concern of British researchers that a fission bomb could be developed. If the Nazis were to succeed first, they would control the world. There was general agreement that there ought to be a preparedness policy. Bush let it be known informally that he was working on a plan. He believed it was vital to find a way to organize the best brains and experts in the country to assist in the accelerated war effort and to help adapt the armed forces to the needs of a highly technical contest.
WHEN Loomis returned east in April 1940 to help Lawrence navigate Wall Street, he was more determined than ever to dedicate his private resources to scientific problems that might have value for defense purposes. Convinced that the United States would inevitably be drawn into the war, he was juggling several disparate projects related to mobilization and believed that priority should be given to things that could yield results in a matter of months or, at most, a year or two. Impatient with the MIT group’s slow progress, he decided that the Loomis Laboratories would no longer muck about with a preliminary long-range exploration of propagation problems. Instead, it would focus on one pressing problem and work to find a practical and efficient solution.
While he was in San Carlos, Loomis had observed some early detection experiments done with a makeshift system that had actually been designed for blind landing tests. Even so, in the course of several tests with the ten-centimeter klystron and a ten-centimeter “Barrow horn” (a galvanized iron hollow cylinder used for transmitting ultrahigh frequencies, named after MIT’s William Barrow), they had actually been able to pick up automobiles and trains a quarter of a mile away, using only a crystal detector with an audio amplifier. Loomis had also observed some of the experiments Hansen and the Varian brothers were performing with one of the first continuous wave Doppler radar sets. Impressed with what he had seen, Loomis proposed to develop a similar airplane locator based on the principle of the Doppler effect. He had brought back several ten-centimeter klystron tubes from California, and he had even convinced Hansen to come back with him to help assemble the setup in Tuxedo Park.
Loomis went up to MIT to arrange for several members of Bowles’ team to be loaned to his laboratory for the summer. At the same time, he wrote Compton another check to help keep the university’s ultra-high-frequency program going. By the end of April, he had assembled a group consisting of Hansen and two young MIT graduate students, Donald Kerr and Frank Lewis, and together they made the drive from Cambridge to Tuxedo Park. There they were joined by MIT’s William Tuller and William Ratliff, now with the Sperry Co. At first, Lewis did not know what to make of Loomis and his lavishly equipped laboratory, and in telling the story later, he joked about his utter astonishment at the exclusive surroundings he suddenly found himself in: “Now this Tuxedo Park is a private enclave where people go who don’t want to be bothered with other people just driving in and saying ‘hello.’ They have a fence around it and they had a gatehouse where you go in and check yourself through. Everybody who was run in and out of there was thoroughly understood by the people that opened the gate. So if they didn’t know you, you didn’t get in.”
As they settled down to work, Lewis began to do “a little inquiring” about the mysterious millionaire who was bankrolling their operation. An enormous amount of equipment was needed, and Loomis “footed the bill generously,” as well as paying the salaries of himself and the other newcomers who were not covered by the original grant. They were joined by several of Loomis’ longtime associates: Garret Hobart; Charles Butt, who was E. Newton Harvey’s research assistant at Princeton and a regular during the summers; Philip Miller, the lab’s manager, machinist, and jack-of-all-trades; and Loomis’ youngest son, Henry, who was in his third year at Harvard but had enlisted in the navy and was due to ship out in six weeks. There was also an impressive stream of visitors, including R. W. Wood, who filled Lewis in on Loomis’ background, how he had made his money, and his close ties to Henry Stimson. As the weeks went by, Lewis came to have a grudging respect for what his wealthy host was trying to accomplish on his own dime:
“Loomis was anxious to have people there who knew about microwaves because he had a feeling microwaves were going to be important,” explained Lewis. “He was a
person who loved to be with the leaders of any one particular enterprise. As such he was called a dilettante by people who thought that was a good name for him. So you had to work for him and talk to him a bit and then you found out there wasn’t anything phony about him at all. He was a first-class scientific person, and he had a lot of money. With those two things he could do a lot of things.”
Aggressive and enthusiastic, Loomis insisted on getting started right away. His time on the East Coast was short, and he had to be back in Berkeley before too long. In any case, he was a hands-on experimenter and believed they stood a much better chance of accumulating useful data if they had a system in operation. It was the way he and Wood had always worked, and it was the way he intended to proceed now. They would just have to make improvements on the fly and incorporate new equipment as it became available. Bush, who had kept a close eye on Loomis’ project at Tuxedo Park, felt the work was promising enough that he had told Ed Bowles, the MIT radar expert who had been collaborating with Loomis on microwave research, if he “needed further support, to let me know.” Bowles did, and Bush directed the Carnegie Institution to allot the sum of $10,000 for Loomis’ microwave detection project at Tuxedo Park.
In the beginning of May, Loomis received a letter from Cooksey telling him that Lawrence was down with a “terrible infection” and updating him on the contracts for the 184-inch cyclotron. Cooksey included a bulletin about a possible breakthrough in radar technology: “Professor Marshall of the Electrical Engineering Department, who, you will remember, is working with Dave Sloan on the micro-wave tube, just back of the partition of my office, told me Friday of some of their successes. . . .” They had tested a tube that oscillated at 50 centimeters and at 2,500 watts and were now in the process of running more checks. It looked as though a piece of cyclotron technology had been transformed into a generator of radio waves at a frequency and power suitable to radar. Loomis was elated by the news. It meant that radar sets could be smaller, while the detail of what they could see increased. The Sloan-Marshall tube, or “resnatron,” could well become the basis of a new generation of powerful, airborne microwave transmitters.
At the end of the letter, Cooksey added that the physicist Emilio Segrè, who was attached to the Rad Lab, had returned from New York and “tells us there is a great deal of hush hush around Columbia in regard to the work that is proceeding on uranium isotope separation and uranium bombs. Apparently the army and perhaps the navy are interested. I have no words with which to express my feelings about the conditions in Europe. I merely know that it is what we must expect. . . .”
Loomis responded with a long letter outlining the status of his various negotiations for the tons of steel laminates for Lawrence’s cyclotron. He confirmed that “U-235” had indeed become “very hot” and that Bush was organizing a conference in Washington the following week for all the scientists who were working on it. As for his microwave work, he wrote, “This whole problem has speeded up enormously because of its immediate war demand” and promised more details later. In a subsequent letter to Lawrence, Loomis wrote that he was working on the Sperry people to provide financing for Sloan’s research. “If the tube is as promising as it seems to be, there ought to be no delay in pushing it.” The Sperry company was building a large factory in Hartford and had bought a private airfield and might be using his Tuxedo facilities as well. He had put Bowles “in charge” of the laboratory. He added that while he hoped to return to California with Lawrence after his planned visit to Tuxedo in late June, “I don’t know how long I will be able to stay out there this summer, if this micro-wave work gets very intense.” It was the first hint Loomis had given Lawrence that he might no longer be able to continue carrying on his share of the responsibility for getting the big cyclotron built. Putting his duty to his country first, Loomis had put his plans for a new life out west on hold.
During this same period, Loomis had a visit from his old friend George Kistiakowsky, who wanted to pass along some troubling information that had come his way. Kistiakowsky had heard that the Germans were carrying out extensive uranium research at the Kaiser Wilhelm Institute in Berlin and feared that with their advanced laboratories and aggressive approach, they might be the first to develop a fission bomb. Kistiakowsky was well aware of Loomis’ reach into the highest levels of science and government and felt sure he would see to it that the facts were communicated to the right people. Loomis decided every attempt should be made to discover the status of the Germans’ uranium experiments, and he enlisted Kistiakowsky to use his network of émigré scientists and European colleagues to gather information and offered to pay for his time and expenses. He then arranged a meeting with Compton and told him what he had learned from Kistiakowsky. On May 9, Compton wrote Bush a confidential letter apprising him of his conversation with Loomis:
As far back as the first suggestion that uranium fission might have a very significant industrial or particularly military significance, he [Loomis] has been very close to groups involved in his work. . . . It is now clear that the German scientists are concentrating major efforts on this problem at the Kaiser-Wilhelm Institute. It also appears clear that uranium 235 could be a tremendously powerful war weapon if it could be secured in substantial quantity and a fair degree of purity. Alfred makes the pertinent suggestion that we really ought to get together some of the most competent men in the field to analyze the possibilities in the situation and be ready to proceed actively if a promising program develops. . . . George Kistiakowsky is intensely interested in the subject (as a weapon which must not be allowed to develop first in Nazi hands) and he is also making an independent study and will report to Alfred Loomis. . . .
Bush promptly wrote to Loomis in Tuxedo Park on May 13:
The matter of uranium fission is exceedingly active. I rather think that the [Carnegie] Institution should take the lead in furthering and correlating this whole matter. Dr. Jewett and I are to see the Army and Navy today on the subject. If we proceed actively we will of course have to use some of our [MIT] Corporation grant, and this matter will probably come up, therefore, at the meeting of the Executive Committee which follows the Finance Committee meeting on the twenty-third. If it is going to be possible for you to be about, I would suggest to Governor Forbes that you be invited into the Executive Committee meeting when the matter is considered. I will be able to give you further information on this particular subject before very long. . . .
On May 17, Bush sent Loomis a quick note informing him that the governor had authorized him to attend the executive committee meeting, “inasmuch as you are so well informed on the subject.”
Loomis, as always, kept Lawrence abreast of the latest news on the uranium front and the behind-the-scenes effort to organize a campaign to move public opinion in favor of taking advantage of modern scientific developments for military purposes. As Lawrence wrote Loomis on May 20, “I gather from your letter that something along this line may be imminent. We in this country certainly do not want to miss any bets in this direction. Incidentally, Mr. Rockefeller would not like to hear this, but we certainly will not be unmindful of the possibilities of discoveries of military value in the energy range above 100 million volts. I am betting that we will find all kinds of fission reactions in many of the heavy elements.”
Three days later, Bush convinced the Carnegie Institution’s executive committee to give him $20,000 “for a defense research project concerning uranium fission.” Even though he shared the prevailing opinion that an atomic explosion was “remote from a practical standpoint,” he agreed that they should push ahead on exploring the possibilities: “I wish that the physicist who fished uranium in the first place had waited a few years before he sprung this particular thing on an unstable world. However, we have the matter in our laps and we have to do the best we can.”
As far as Bush was concerned, the Carnegie money was only a drop in the bucket. He believed it was vital that science and technology were broadly mobilized for the war, which would prov
ide him with a way to address what he saw as by far the most pressing military problem—the need to rapidly improve the country’s air defenses. He was convinced that airpower was the backbone of military strength. America, which had been isolationist since the First World War, was vulnerable only to transatlantic attack. Radar held the key to revolutionizing warfare by providing a better means to track the enemy and accurately destroy targets. But to date, the army had ignored radar’s potential for defensive action and could not be interested in sponsoring any research. The navy had developed its own detection devices but was woefully short of funds to do further research. As Bush had complained to former president Hoover in a letter a year earlier: “The whole world situation would be much altered if there was an effective defense against bombing by aircraft. There are promising devices, not now being developed to my knowledge, which warrant intense effort. This would be true even if the promise of success were small, and I believe it is certainly not negligible. . . .”
The “intense effort” Bush had in mind would require unprecedented cooperation among three distrustful—at times even hostile—communities: military, science, and industry. It would also require an enormous amount of money. But Bush believed with the right leaders working together, he could create a new military research organization that could exploit the technical advances that were indispensable to modern warfare. “I was located in Washington, I knew government, and I knew the ropes,” he would say later. “And I could see that the United States was asleep on the technical end.” As head of the Carnegie Institution, he was held in high regard by the scientific establishment, and he knew he could count on the backing of four men who figured prominently in its ruling echelon: Compton, Conant, Jewett, and Loomis. Compton and Conant headed major universities; and Jewett was president of the National Academy of Sciences and Bell Labs, easily the most respected industry research center. Loomis was a well-connected banker, but in Bush’s view he had gained acceptance into that brotherhood by virtue of his “real contribution to scientific knowledge.” What drew these men together, he explained, was “one thing we deeply shared—worry.”
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