During the daytime raids, all that was required was to bring the pilots into the general vicinity of the incoming stream of bombers, and then the pilot took over, using his own sight and judgment to select targets and gun down the enemy. The nighttime raids, however, demanded much more accurate course directions than these radar sets could deliver. It also relegated experienced pilots to the role of hapless chauffeur right up to the moment when they were close enough to see the blur of the enemy plane against the sky; only then, at the last minute, could they press home their attack.
It went without saying that this complicated system required a very high order of skill and virtuosity on the part of the ground controller, the radio operator on the plane, and the pilot, and that in wartime Britain there was a critical shortage of such talent. In addition to the radar system’s technical shortcomings, the RAF’s Blenheim bomber planes lacked the speed and weaponry required to take on the Luftwaffe and were having little success after sundown. The radar system that had enabled the RAF to function so brilliantly during the daylight raids of the Battle of Britain left them blundering in the dark. The night fighters desperately needed more sharply defined radar beams, and that meant microwaves. The magnetron promised the development of radar sets using much shorter wavelengths than the 1.5 meter then in service. Only at wavelengths below 10 centimeters could an antenna be small enough to be installed on an airplane yet still produce a sharp enough beam to give a highly accurate read on the enemy’s location. This electronic eye—which could see through clouds, fog, and cover of night—was Britain’s most pressing radar need, Loomis told them, and the laboratory’s first priority.
After Loomis’ briefing, the various industry representatives on the microwave committee gave updates on their progress in manufacturing the components. Although the original timetable had been extravagantly optimistic, there were no delays. Incredibly, almost all of them would meet the deadline. The following day, Loomis and Lawrence declared the new lab open for business. Bell delivered the first five copies of the British magnetron right on schedule. After everyone had a chance to admire them, they were locked in a safe in DuBridge’s office.
Frank Lewis, one of the young MIT researchers who had joined Loomis’ Tuxedo operation, had been the first to arrive and along with several other members of the original staff spent the first few days giving demonstrations of their microwave aircraft detector, mounted on the Loomis Laboratories truck, to the new recruits at the East Boston Airport. “Loomis brought the entire crew from his lab at Tuxedo Park,” he recalled. “We picked up all the equipment we had originated, and all of the stuff we had bought to work with, and we put it into the didey wagon and we drove the truck up there.” Having already heard reports of the British tracking systems, and the two-hundred-mile range covered by their equipment, some of the new recruits scoffed at the Tuxedo device’s measly two-mile range. Young, cocky, and supremely confident, they were certain that with their collective brainpower they would invent a radar system that would whip the Nazis and win the war.
The first week in Cambridge was tense and bewildering. Loomis was creating the radar laboratory out of thin air, and the fact that it did not really exist yet, combined with all the secrecy surrounding the project, made it hard to know exactly how to proceed. Everyone was told the project they were going to work on was for the military: “We had to keep our mouths zipped shut all the time,” recalled Lewis, “and we had to be sure that we were working with people who were cleared for this.” As they began to set up shop and contact the various manufacturers about the delivery of parts and supplies, they realized for the first time the extent to which Loomis had simply willed the enterprise into being. Seeing how far the country still was from entering the war, and knowing from firsthand experience how difficult it was to move the services in a new direction, Loomis had essentially hijacked the project for himself: “The microwave committee, which was a fictitious organization that was set up by Alfred Loomis, had made arrangement with all these government contractors to work on these problems,” explained Lewis. “They had no official appointment from the federal government to do this. But Loomis got them all talked into doing it, and they were so convinced that they were it, they went right ahead. And it’s a good thing they did.”
For all Loomis’ wealth and freewheeling style—he had used money out of his own pocket to jump-start the new lab—the government had him on a short leash. The feasibility of microwave radar had to be established quickly if the project was to get the green light and receive further funding. “Loomis got all the radio manufacturers that he could get his hands on to buy the idea that this was going to be a big show, and he would be the main propellant, and they’d better do what he told them,” said Lewis. “He didn’t put it in those words, but that’s what he was saying.” As far as the salesmanship was concerned, “It took the talents of a Loomis and a Compton,” agreed Bowles, adding that there was “more than a bit of skullduggery” that went into the early contracts, most of which were negotiated verbally and not set down on paper until months later, creating all sorts of havoc. “We pretty well got away with murder.”
Everyone agreed that the new lab needed to have some sort of title, but a descriptive yet nonrevealing name was hard to find. Finally, one of the Berkeley group suggested calling it the MIT Radiation Laboratory in honor of Lawrence, who was largely responsible for their all being there. The misleading name would account for the large and rather sudden concentration of experimental physicists and cyclotroneers in Cambridge, while at the same time it would be descriptive, in a sly way, of their purpose. In the interests of secrecy, they also hoped the disguise would fool outsiders into thinking that they were engaged in research as altogether remote from the war effort as nuclear fission, which was considered of no practical significance as compared to radar. The “Rad Lab” met with unanimous approval and was officially adopted.
As the parts began to appear, and more physicists arrived, a loose structure took form. The immediate work was divvied up into seven technical sections based on the components, and as everyone had expertise in different fields but not specifically in the radar set’s dissembled parts, the selection process was somewhat random. “We chose up just like a baseball team,” said Rabi. “We chose up sides. What would we take?” Turner took receivers; Bainbridge took pulse modulators; Lewis took klystrons; and so on. Rabi opted for the magnetron, though as he recalled later, “I had no idea how it worked.” He was hardly alone. Most of the young nuclear physicists, freshly arrived from their university laboratories, knew little to nothing about microwave electronics and had only the vaguest understanding of how the British ten-centimeter magnetron would transmit power for a radar set. But then no one else did, either. Microwave radar was virgin territory and the magnetron brand-new technology.
Rabi was confident that he and his fellow physicists had “the intellectual mobility” to find out everything they needed to know. As he was in charge of the magnetron group, he decided to go around to MIT and ask some of their electrical engineers for advice. “After talking to them I could see they didn’t know anything, either,” he said, “so we started absolutely fresh and designed magnetrons.” Everybody did the best they could, hopping back and forth across organizational lines as needed and throwing out ideas to members of one group or another. Caught up in the excitement of the adventure and imbued with a sense of their own importance and assured success, they plunged into the unknown.
“It’s simple,” Rabi boasted in one of the early sessions, when they were seated around a table, staring at the disassembled parts of a magnetron. “It’s just a kind of whistle.”
“Okay, Rabi,” challenged Edward Condon, one of the Berkeley physicists recruited by Lawrence, “how does a whistle work?” The long silence before Rabi attempted an answer spoke volumes about how much they still had to learn.
Bowen was struck by the easy camaraderie that prevailed at the lab: “Everyone worked long hours and did not spare themselves.
Here was the cream of American scientists, hell-bent on doing all they could for the war effort.” There was little time for relaxation, but on Friday nights the gang all gathered at the bar behind the Commander Hotel just back of Harvard Square, where Luis Alvarez and Ed McMillan, among others, were staying. Inevitably, this was soon dubbed “Project 4,” a last and vital addendum to the lab’s must-do list. Bowen generally took a lot of ribbing on these outings, particularly because the mural decorating the walls of the bar depicted various patriotic scenes “dear to the hearts of all Americans”—the Boston Tea Party, Paul Revere’s ride, and Minutemen shooting through the trees at the Redcoats. “The message was loud and clear—this was where they beat the pants off the British,” he recalled with amusement. “Proceedings usually began with an expression of solidarity, a friendly toast to the British—‘The hell with the Limeys.’ ” There were also weekly dinners in Chinatown, limerick competitions, and the “laugh meter,” featuring jokes only physicists could appreciate. As a break from the tension, everyone read science-fiction novels and dog-eared copies were passed around.
Loomis moved into the Ritz-Carlton Hotel in Boston, where he occupied a lavish suite—particularly given the spartan dormitory quarters assigned to his physicists—and often hosted private dinners for Bush and other NDRC officials. Because of his long hours at the lab and erratic travel schedule, Ellen spent most of her time with her parents in Dedham, away from the noise and dirt of the city. Because Hobart was also immersed in the radar project, and both her boys were now enrolled at the Fay School in Massachusetts, Manette had an excuse to be in Boston and came as often as she could. She and Loomis continued to see one another secretly and were so circumspect that it seems neither their families nor anyone at the lab guessed what was going on. They were greatly helped by the fact that Boston had been flooded with hundreds of newcomers, and people’s lives no longer conformed to a regular pattern. Young men were scattered in hotels and temporary housing all over the city, many of them separated from the wives and children they had left behind. Young women who had never worked before were taking jobs in town and going about in slacks and sweaters. There was a general feeling of chaos and things building toward a crisis, and it tended to make people more casual than they might have been in more orderly times. Later, the dim-outs made it hard to get around at night, and the darkness no doubt covered a multitude of sins.
THROUGHOUT that fall, work proceeded at a furious pace that DuBridge, with heavy irony, described as “the blitz.” The physicists set about trying to understand why the magnetron worked so well and initiated theoretical and experimental studies. Rabi’s group quickly discovered that the magnetron could produce far more power than the British had suspected and soon enough was known to improve the efficiency considerably. As the parts were delivered, work was begun on testing and adapting them, while other groups designed components for use in an aircraft.
By mid-December, the lab had almost doubled in size and was employing thirty-six people: thirty physicists, three guards, two stockboys, and an indomitable secretary by the name of Edythe Baker, whose idea it had been to paint the windows. It had also outgrown its original space, first moving upstairs, via a spiral stairway, to the second floor and then upward again to the top of Building 6. There they had erected a crude wooden “penthouse,” about twenty by fifty feet, covered in green tarpaper, and a second story was already being added. The so-called Roof Laboratory soon became the main hub of activity as the various components they had ordered started to arrive and they began to hitch up the radar system.
On December 16, emboldened by their progress, Loomis wrote out on the blackboard a schedule of ambitious target dates for the AI project:
Goal 1:
By January 6, a microwave system working in the Roof Lab.
Goal 2:
By February 1, a working system mounted in a B-18 bomber supplied by the Army.
Goal 3:
By March 1, a working system adapted for an A-20A attack bomber (the plane most likely to be used for night combat).
Loomis and Lawrence set up a group dedicated to assembling the system and appointed Alvarez expediter to ensure that the deadlines would be met.
By late December, a complete ten-centimeter pulsed microwave radar set was assembled on the roof, and they would soon be able to begin testing it against buildings in Boston, just across the Charles River. This was a two-antenna system, with separate parabolas for transmitting and receiving. The two large dishes, mounted in a rickety apparatus in the Roof Lab, looked like two monstrous black eyes staring out at the golden dome of the State House and the Boston skyline. The physicists, shivering in their unheated penthouse laboratory, had put together the parts and wrestled the unwieldy system into operation. Now the only question was, Could their electronic eyes see?
Loomis took a quick break for Christmas, heading to Hilton Head for the holidays. All three of his sons were away at war, but Ellen would be there, along with Julia and Landon Thorne and their family. He invited along the Comptons, as well as Bowen, who was on his own for the holidays, as his wife was stuck back in England owing to wartime travel restrictions. Loomis knew the Welshman had more than earned a rest after an exhausting few weeks demonstrating the British AI and ASV (air-to-surface vessel) Mark II long-wave radar sets to American military personnel. Bowen had showed off the performance of the Mark II, which he had helped develop and which had been fitted into a U.S. Navy PBY aircraft. Flying over merchant ships in the Atlantic, he had successfully picked up an echo from a capital ship at a range of about sixty miles. Satisfied that this was the equipment to adopt, the navy had finally agreed to take over for the Tizard Mission, placing orders with the Philco Corporation for seven thousand copies of the ASV radar systems. An additional ten thousand sets were ordered from Canada’s Research Enterprises Ltd. Ultimately, the procurement would run into hundreds of thousands of sets, the majority of which would be used by American forces.
Just before New Year’s Eve, Roosevelt gave a speech promising aid to Britain from the “Arsenal of Democracy.” Bowen, who was heartened by the president’s address, only hoped it had not come too late. As Loomis and his friends rang in the new year, they had much to celebrate and much yet still to do. Loomis’ best estimate was that the project would take at least two years and millions of dollars in government funds. England was being methodically bombed by the Luftwaffe. The dark winter of the Blitz had begun.
ON a cold, clear morning on Saturday, January 4, 1941, two days ahead of schedule, a radar beam was sent out from the Roof Lab, and the first echoes from the Christian Science church tower in Boston were detected. In less than eight weeks after they walked into the Rad Lab, Loomis and his band of microwave novices had managed to build a working prototype of a radar system. It was far from perfect; in fact, there were so many tuning stubs introduced at so many different points that coaxing the tuning was “distinctly an adventure.” But it was a start. An excited DuBridge telegraphed Lawrence at home in Berkeley, where he had returned just in time for the birth of his second son on January 2:
ROOF OUTFIT IN FALL [sic] SWING LOOMIS IS JUBILANT. . . . FEBRUARY FIRST DATE LOOKS EASY IF SHIP COMES IN HOPE YOU ARE AS PROUD OF YOUR BABY AS WE ARE OF OURS=LEE
Loomis’ euphoria was short-lived. It quickly became apparent that there were almost as many things wrong with the system as there were right. To begin with, it was poorly designed and was altogether too large and unwieldy. The main problem still facing them, and one that seemed to have no easy solution, was that the radar system they were charged with designing had to be compact enough to fit into the nose of a fighter plane. For the system to be small enough to be practical, they would have to find a way to use a single antenna, or “duplexer,” for both transmitting and receiving. Unfortunately, no one knew how to build such a device.
An air of gloom descended on the Rad Lab. In a sense, they were back to square one. The design of the duplexer—what the British called a “TR” (transmit-re
ceive) box—had confounded them from the beginning. Without a duplexing or switching device, or some kind of protection, the main transmitted pulse would burn out the receiver crystal. Because the outgoing signal was a million times stronger than the incoming echo, the question was how to use a single dish that poured out a powerful radar beam without swamping the feeble echo that bounced off the target and returned in a few microseconds.
DuBridge organized several teams to attack the problem. From day one, the physicists at the Rad Lab were guided by Loomis’ insistence on a hands-on approach and practical rather than theoretical solutions—they lived by the law of “cut and try.” Finally, after some frantic efforts and several failed attempts, a makeshift single-antenna system was made to operate. The team, under Jim Lawson, who happened to be an amateur radio enthusiast, succeeded in fashioning a TR box by using a klystron amplifier as a buffer in the line from the antenna to the receiver crystal. As Alvarez observed, “If we had been paid in proportion to our contributions to the success of the first microwave radar program, Jim Lawson would have earned more than half the monthly payroll.”
Lawson’s roof team spent hours on end fiddling with the homemade contraption, one of them working in a bulky coonskin coat against the cold. The signal-to-noise ratio in the receiver made it very hard to stay on the proper frequency. One day, while they were working with the system, they picked up a great deal of interference that made it impossible to pick out a signal. “We nuclear physicists had absolutely no idea what to do,” recalled Alvarez. Then one of the Berkeley group asked if anyone had a pair of earphones. An MIT engineer ransacked the classrooms and finally found an old pair in a student laboratory. When they hooked up the earphones to the radio receiver, they heard a voice crackling: “Hello CQ, CQ, hello CQ.” The mysterious noise they had been hearing was a local amateur radio operator announcing himself over the airwaves. After taking some added precautions, Alvarez noted, “We were back in the radar business again.”
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