Certain details and images of Turing at Bletchley Park have remained a part of the cultural image of him—as recently as September 2009, in discussing the possibility for posthumous honors for Turing, Geoffrey Wansell referred in the Daily Mail to some of his well-known habits: “Notorious for his idiosyncrasies—he would tie his tea mug to the radiator so that no one else could use it, and ride his bicycle wearing a gas mask simply to avoid hay fever—Turing was, nevertheless, keen to ‘fit in’ … Despite his high-pitched voice and increasingly odd behaviour—he would sometimes run the 40 miles from Bletchley to London to attend meetings.” Wansell points out, “Turing was critical to the war effort.” In his spare time at Bletchley Park, Turing, like Zuse, was also thinking about chess, partly because the workforce at Bletchley played a lot of chess in off hours. As a result, Turing’s imagination, which seems always to have had a philosophical bent, turned to another thought machine—one that would use probable outcomes to extrapolate the relative benefits of various chess moves. The idea was to create a machine that could simulate human decision making. He also thought about mathematical problems, saying, “Before the war, my work was in logic and my hobby was cryptanalysis, and now it is the other way round.” In October 1941, right about the time that Mauchly was feeling out Atanasoff about whether he could use some of his ideas, Turing and a few of his colleagues were writing to Winston Churchill to request additional typists and other staff. In 1941, the war was going better than it had in 1940, partly because Hitler broke with Stalin and attacked the Soviet Union in late June of that year, giving himself only about three months to take the major Russian cities before the onset of winter—according to historian Andrew Roberts, if he had attacked two months earlier, as originally planned, he might have had a chance of prevailing. Germany did manage to take Kiev, Minsk, Kharkov, and Rostov, though just before Pearl Harbor they had to call off the attack on Moscow. The Allies were making progress in Africa, too, but at Bletchley Park, those working on the Enigma cipher were wondering about the Americans. They were certain that Roosevelt would enter the war fairly soon and were nervous about whether the secrets of their methods could be entrusted to the American navy. As it turned out, the Germans declared war against the United States on December 11, 1941. According to Turing’s biographer Andrew Hodges, when British intelligence then attempted to share information derived from the operations at Bletchley Park about German U-boat locations in the Atlantic with the U.S. Navy—in particular, “the operation of fifteen U-boats off the American coast at the declaration of war”—the navy ignored the information, resulting in huge losses in the Atlantic at the same time the United States was deploying many vessels to the Pacific. The war in the Atlantic, which had been going well, suffered serious setbacks.
In Ames, the entry of the United States into World War II brought work on the ABC, particularly the electric spark card-marking mechanism, to a halt. Though Atanasoff and Berry felt that if they could find the right card stock, they could make the charring mechanism work, the start of the war in America made supplies and parts of all kinds scarce, and Atanasoff had to turn his full attention to his defense project. Berry had to turn his full attention to looking for a job in the defense industry—he was due to receive his master’s degree in May. In their spare time, both men assembled and polished the information needed for the ABC patent application, which, Iowa State continued to assure Atanasoff, would be filed any day. In the summer of 1942, Berry married Atanasoff’s secretary and departed to take a job in California. In September, Atanasoff himself left Iowa State for a job at the Naval Ordnance Laboratory in Washington, D.C., though he retained his full professor position at Iowa State with the plan of returning after the war. He had done well in Ames—his salary was $5,800 a year, more than twice his starting salary in 1930, which meant that his salary for defense projects would also be a high one. And he was convinced that between them, the patent attorney in Chicago and the administrators at Iowa State had the patenting of the ABC well in hand. The machine itself he left in the basement of the physics building.
Chapter Six
The John Vincent Atanasoff who worked at the Naval Ordnance Laboratory for the next seven years, through the war and then on several projects afterward, was the same man who had made his self-confident, energetic, innovative, and sometimes abrasive way through school, college, graduate school, and a successful teaching career. He worked unceasingly and impressed everyone who knew him, but he did not always fit smoothly into the navy’s way of doing things, nor was he always happy at the way projects for the navy started and stopped according to what seemed to him to be whims on the part of the admirals in charge.
Lura and the children stayed behind in the house on Woodland Street in Ames—Atanasoff commuted throughout the war, a thirty-six-hour train trip each way on top of a weekly work schedule that could run as much as sixty hours. At first, he was put to work on developing mines and depth charges that would operate acoustically rather than magnetically. At the beginning of the war, especially in the Atlantic, mines were used that detected ships by sensing magnetic waves. When they then exploded, the shock wave of the explosion would damage the hull of the passing ship. These mines could be cleared or disarmed by minesweepers dragging electrical cables through an area and passing a large pulse of electric current through the cables, a method called the Double-L Sweep. The navy wanted a mine that could be triggered by the sound of a nearby propeller or the clanking of the metal plates of a ship’s hull.
Atanasoff had never specialized in acoustics, but as always, he mastered the material with a few months of intensive reading, and soon he was in charge of the entire acoustics division at the NOL, supervising about a hundred men. He directed projects on the acoustical properties of explosives, acoustical detection, acoustical location, and numerous other topics. He was so inventive that he was later cited for, among other things, “his unusual imagination and exceptional mechanical ingenuity, his enthusiasm and indefatigable energy and zeal.” Part of his citation might have easily described the invention of the computer: he “has succeeded in conceiving of the solution to an urgent military problem which had been considered insoluble. Having conceived of the answer to the problem, he saw it through design, production, and test to the final timely adoption despite almost insurmountable obstacles.” Some of the men Atanasoff hired he knew from Ames—almost all research not related to the war effort had been shut down by mid-1942, so there was a large talent pool to draw from. In the midst of all of this, he still had time for hobbies, one of which was a comparative study of alphabets. On his visits to Ames, he tried to keep track of the progress of the patent application for the ABC, but his efforts proved frustrating—he was never able to find out exactly what the college was doing about the patent or to persuade them to move more quickly.
Atanasoff’s desk was in the Naval Gun Factory—it is an index of his powers of concentration that he got so much work done in the midst of a constant din. Atanasoff held a very high security clearance, so one day in the late spring of 1943, he was surprised to look up and see John Mauchly standing in front of him. Mauchly sat down and lit a cigarette, and, as far as Atanasoff was concerned, they had a pleasant conversation in which they first discussed what they had been doing since they’d last met almost two years before.
Mauchly had a lot to tell. He had become involved in a project at the Moore School, calculating trajectories for aiming large pieces of artillery. The proper aiming of a cannon had to take into account all sorts of factors: the elevation of the cannon and the elevation of the target, wind speed, wind direction, air temperature, humidity, and numerous others things. The variables were organized into firing tables, which were calculated by women employed by the Moore School working on Monroe calculators, but, as with Atanasoff’s calculations for the dielectric constant of helium, the calculations were tedious and time-consuming—the army was inventing and producing weapons faster than they could be put to use. At the Aberdeen Proving Ground, the Bush
Differential Analyzer—the analog machine based on Babbage’s Differential Analyzer and invented by Vannevar Bush, the man who was now the head of National Defense Research Committee—was making some headway on the necessary calculations, but the Bush Analyzer could only solve differential equations with up to eighteen variables. Mauchly was aware of the army’s problem and now told Atanasoff about his new colleague, Eckert. He explained that the two of them were attempting to devise a machine that the army could use to make the necessary firing-table calculations.
Mauchly had submitted two proposals. The first, seven pages entitled “The Use of High-Speed Vacuum Tubes for Calculation,” was submitted in August 1941 and described “an electronic device operating solely on the principle of counting.” He suggested that it would do the same jobs as analog machines, but do them more quickly. The army authorities in charge of research at the University of Pennsylvania apparently did not understand what he was getting at and also did not consider him a serious contender for research funding—one man, Carl Chambers, is quoted by Scott McCartney as saying, “None of us had much confidence in Mauchly at that time”—a sentiment Atanasoff would have agreed with.
The pivotal figure in Mauchly’s career was a twenty-eight-year-old lieutenant, Herman Goldstine, who happened to have a Phi Beta Kappa BA in mathematics and a PhD in ballistics from the University of Chicago. Before being drafted into the army, he had taught at the University of Michigan. Once he was drafted, a former professor found him a position at the Aberdeen Proving Ground. Goldstine was put in charge of the firing tables. When he took over, each table took a month to produce. Goldstine’s first thought was to hire more women to do the computations, but when his wife, Adele, also a mathematician, set out to find more female math students (female math students could do the calculations and were not as essential to actual combat operations), she could find only a few. The Bush Analyzer was too slow and hard to maintain in working order. It was Goldstine who heard of Mauchly and his idea, and Goldstine who found Mauchly and asked him about it.
But neither Mauchly nor John Grist Brainerd, the Moore School’s liaison with the army, could find a copy of Mauchly’s seven-page proposal, now eight months old. At Goldstine’s behest, Mauchly, Brainerd, and Brainerd’s secretary put together as good a new proposal as they could come up with and took it to Aberdeen.
A major Allied setback that was not understood until after the war was the fact that the Germans also managed to crack English codes, specifically the code that routed convoys, Naval Cipher No. 3. Even though they did not have the benefit of a machine like the Bombe to do so in real time, they could often figure out the “size, destinations, and departure times,” according to Andrew Roberts, but “instead of recognizing the danger, the Admiralty put the U-boats’ remarkable success in intercepting convoys down to the advanced hydrophone equipment they used … Naval Cipher Code No. 3 was not replaced with No. 5, which the Germans never cracked, until June 1943.” The spring of 1943 saw the sinking, between March 16 and March 20, of twenty-seven Allied ships on their way from New York to Liverpool; 360 seamen died in the battle. Captain H. Bonatz, of the Beobachtungsdienst, a German naval code-breaking organization, later recalled, “The Admiral at Halifax, Nova Scotia, was a big help to us. He sent out a Daily Situation Report which reached us every evening, and it always began ‘Addressees, Situation, Date.’ ” The rote repetition of the first words of the communication enabled the Germans to break the English codes every day in the same way that the repeated three-letter signal had helped the Enigma decoders. At Bletchley Park, the decoders could tell by what they were decoding that the Germans had access to Allied coded information. But code breaking in Germany was fragmented among various services and commands—there was never a well-funded center for deciphering Allied messages like Bletchley Park.
Turing, at this time, was in the United States. He spent a while at Bell Labs, working on a method for enciphering speech, where he discussed his paper “On Computable Numbers” with Claude Shannon. Shannon, himself a graduate of MIT, had written his master’s thesis in 1937 on using relay switches to solve Boolean algebra problems. He also had the insight, like Atanasoff, that the binary arithmetic that relay switches represented would simplify information systems. His master’s thesis, written when he was twenty-one and published when he was twenty-two, is considered to be one of the most important, if not the most important, master’s thesis of the twentieth century. Shannon had studied neurology, too. According to Hodges, when Turing and Shannon shared their ideas about “thinking machines” in March 1943, “they found their outlook to be the same: there was nothing sacred about the brain, and if a machine could do as well as the brain, then it would be thinking—although neither proposed any particular way in which this might be achieved.” At the end of March, Turing returned to England on The Empress of Scotland.
It was in this context that Mauchly submitted his second proposal to Goldstine and Goldstine sought authorization from the army to fund the project—conditions seemed dire and the army was desperate enough to grant $61,700 (the equivalent of $750,000 in 2010 dollars) to Mauchly and Eckert.
According to McCartney, Mauchly and Eckert discussed their ideas casually—sitting around the Moore School and spending time drawing on napkins in a restaurant nearby. “A machine could be designed to do nothing but count the pulses of electrons, with the pulses representing numbers, and to crunch numbers in different ways to solve different problems. Instead of moving gears and wheels in a conventional calculating machine, Mauchly thought he could build a machine with no moving parts: only the electrons would course through the machine.” Eckert agreed with and was inspired by the idea of electronic calculation—he had already devised a method of calculating smokestack emissions that sent a beam of light through a cloud of emissions. The amount of light that got through was then measured, giving a reading on the density of the emissions. There is no evidence that Mauchly and Eckert kept a record of their deliberations or that they elaborated on the theory behind the ideas that they passed back and forth between their meeting in June 1941 and the submission of the first proposal in August 1942.
It was with his authorization in his possession that Mauchly came to visit Atanasoff at the gun factory in April 1943, but he said nothing about it. After chatting amiably for a while, he did ask Atanasoff a few questions about the ABC and about Atanasoff’s computer design ideas. Atanasoff, still underestimating Mauchly in several ways, was as forthcoming as he had been before. He felt, after all, that he and Mauchly were friends and that they were on good terms. He also had few opportunities to discuss his passion for electronic calculation. It was only later, after thinking about their meeting, that Atanasoff wondered how Mauchly had gotten security clearance to visit him—to just show up. Though he asked around, he never got an answer to this question more satisfactory than the vague supposition that possibly Mauchly had connections, since his father was a Washington, D.C., scientific eminence.
After the first visit, Mauchly stopped by off and on, always chatting in a friendly way about personal matters before asking a few specific computer questions. At one meeting, he asked about the progress Iowa State was making toward patenting the ABC, but Atanasoff couldn’t answer that question with any certainty—he was working so hard at the NOL that he had neither the time nor the energy to keep after the college. Nor could Atanasoff say that he had kept on top of recent developments in computing—he was simply too busy. It seems clear from these conversations that Mauchly was using his access to Atanasoff both to probe him and to gauge whether the computer he was developing with Eckert might turn out to be profitable. The visits went on for three years.
Frugality was never a feature of ENIAC, which began to take shape in a large unused room at the Moore School in July 1943. At first the engineering team numbered twelve—Goldstine, Eckert, and Mauchly oversaw the general design (with Eckert in charge). Other members of the team were put in charge of individual components and, since the army was in
desperate need of the firing tables, the Moore School team worked with seven-day-a-week dedication. Eckert’s most controversial decision was to use vacuum tubes—at first five thousand, a number that grew to eighteen thousand (in part because the army, in its desperation, pushed Goldstine to expand the capacity of the machine). Such a number was unheard of, not only because vacuum tubes themselves were considered unreliable, but also because wiring so many together would amplify the malfunction of any single one. But Eckert was determined to use the tubes and decided to make them less prone to burning out by obtaining only the best tubes and then operating them at a much lower voltage than recommended, as well as never turning the machine completely off—the current could be reduced to a trickle to keep the tubes warm and to guard against the potential danger of thermal shock.
Eckert was dedicated to testing every part. According to Scott McCartney, in order to choose his wiring, “Eckert acquired some mice in cages and starved them for a few days. Then he put different kinds of wire in their cages to see which kind they enjoyed eating. The least appetizing brand was used in ENIAC.”
Eckert and Mauchly also decided to use a decimal counting system, sort of an electronic version of the Monroe calculator—if the number 345,679 was entered into the calculator, the counter in the ones column would flash nine times, the counter in the tens column seven times, the counter in the hundred column six times, and so on. But the tubes were much faster, of course, than a person tapping a calculator—a number would register in two millionths of a second. The advantages of speed were balanced by the dangers of unreliability, and so the machine, which was huge, had to have repairability built into it—it was so important that every tube be accessible in case it burned out that the machine was designed in discrete units with doors that opened into the mesh of wiring and tubes, and it took so much power to run the machine that Eckert had to include safety switches on every door to prevent electrocution. In addition, because the machine was decimally based, it could only add and subtract, not multiply, but Eckert’s idea was that it would be so fast that a binary number system would not improve overall performance and would require an extra piece of input- output hardware.