At the same time that we were seriously considering the possibility that the Germans would prepare an impenetrable radioactive defense against our landing troops, we also had to plan confidently on a successful invasion. On the latter assumption, we again began to explore ways to exploit the intelligence opportunities that the invasion would open up. Dr. Bush and I urged Major General Clayton L. Bissell, now G-2, to establish a mission similar to the one that had produced such excellent results in Italy. Our recommendations fell into the grist mill of the General Staff and became the subject of a number of staff papers which contributed nothing of value to anyone’s knowledge of the situation. At first I went along with the staff’s efforts to develop a universal system which could be applied to our specific needs, but finally, by the end of March, 1944, I felt time was running out and I insisted that Bissell bring the matter of a scientific intelligence mission to the personal attention of General Marshall without further delay. The next day, G-2 proposed to the Chief of Staff “that a scientific intelligence mission be organized in the Military Intelligence Division, with the assistance of General Groves and Dr. Bush, and that it be sent into various portions of active theaters at suitable times. The military and civilian scientific personnel will be selected by General Groves and Dr. Bush, and the intelligence and administrative personnel by Assistant Chief of Staff, G-2.” This proposal was approved by General Joseph T. McNarney for the Chief of Staff on April 4.
Colonel Pash was again designated chief of the mission. Bush and I agreed on Dr. Samuel A. Goudsmit, an extremely capable atomic physicist, and one not involved with the MED, for the scientific chief. An advisory committee to guide the work of the mission was established, consisting of representatives of the Director of Naval Intelligence, the Director of the OSRD, the Commanding General of Army Service Forces, and the Assistant Chief of Staff, G-2. This committee concentrated on the nonatomic areas.
To make absolutely sure that his operations would be fully supported, Pash was provided with a letter to General Eisenhower, signed by the Secretary of War, saying: “I consider it [the mission] to be of the highest importance to the war effort. . . . Your assistance is essential, and I hope you will give Colonel Pash every facility and assistance at your disposal which will be necessary and helpful in the successful operation of this mission.”
Pash visited England in mid-May to make arrangements for establishing the mission on the Continent, and to open an Alsos office in London. Because of his letter, the mission obtained full support from General Bedell Smith; Brigadier General E. L. Sibert, G-2 of First U.S. Army Group; and Brigadier General T. J. Betts, G-2 of SHAEF; as well as from Conrad and the members of his section, who had been well prepared for Alsos by Calvert. The understanding co-operation given to Alsos by all these agencies throughout the European campaign made the difference between failure and the brilliant success it achieved. With their assistance, Pash was able to establish special channels for Alsos reports and targets. He also succeeded in negotiating out of existence the many problems that might have arisen in connection with seizing intelligence targets in liberated friendly territory.
In June, at the height of his preliminary work in London, Pash was interrupted by an order from Washington to investigate a most disturbing report from Italy. We had just learned that our efforts to bring a number of Italian scientists from German-occupied Rome had failed. In spite of the reports of success from an OSS agent to the effect that he had been in touch with these scientists, Pash now discovered that in fact no contact had ever been made. Fortunately, Pash was able to conclude after a severe interrogation of the agent that no lasting damage had been done. Pash ordered him to leave Rome at once, and never to talk about the operation. Needless to say, he was never used on our work again.
Pash’s trip to Italy was not in vain, however. June 4, 1944, was notable as the day on which Rome finally fell to the American Fifth Army. With his customary initiative and energy, Pash left Naples immediately to secure the original Alsos targets in Rome. Most of these men were connected with the physics laboratory of the University of Rome, which was placed off-limits to Allied troops. The following day he took over the National Council of Research.
The pressure of business in London did not permit Pash to remain in Italy any longer, so he turned over the mission’s activities there to Agent Bailey, who had accompanied him on this trip, and returned to England. We took steps promptly to reconstitute Alsos in Italy and, on June 17, Major R. C. Ham, Pash’s Executive Officer, left London to establish the Mediterranean Section of Alsos. I had already arranged for Major Furman and Dr. John R. Johnson to join him in Rome to see what information might be developed there.
They arrived in Rome on June 19, and immediately started investigations that extended over the next six days. Drs. Wick, Amaldi and Giordani, all of the University of Rome, were questioned about their research activities. Their replies confirmed earlier indications that Italian scientists had had very few opportunities to visit Germany before the Italian armistice in July of 1943, and that practically no interchange had taken place since then. Italian scientific research and development had been generally disorganized and was almost militant in its resistance to the Fascist state—militant, at any event, after the armistice.
Both Wick and Amaldi had served in the Italian Army and since the surrender had been hiding in Rome. During the war they had engaged in theoretical research principally on isotope separation, neutron, infrared and cosmic rays. They had no direct information about German research in the field of nuclear fission, for they had never been asked to do any work with or for the Germans. They claimed not to understand the significance of heavy water, and they were not aware of any new activity at the Joachimsthal uranium mines in Czechoslovakia.
Wick had made a trip into Germany during June and July of 1942, and had seen and talked at some length with a number of German physicists at that time and, together with Amaldi, had been shown some of the correspondence between various German scientists; thus they were able to supply us with some useful information. They were most co-operative, and what they gave us was the basis for the compilation of brief accounts of the activities and locations of a number of Germans who were of outstanding interest to the MED. Although later investigations in Germany proved that some of the information obtained in Rome was not wholly accurate, in the main it was well worth the trouble we had gone to in collecting it.
The second phase of the Alsos mission, however, in France and Germany, was where our efforts really paid off, for here we were finally successful in obtaining positive rather than negative atomic information. In addition Alsos obtained important scientific information on matters, such as long-range rockets, outside its main preoccupation. This is a long story which cannot be told here, but G-2 was concerned about a number of scientific intelligence problems. In general, scientific intelligence had been a relatively neglected field in all the intelligence agencies, and the co-operation between G-2 and MED, with the advice and help of the OSRD, in Alsos was a pioneering achievement of significance.
Staffing of Alsos progressed gradually. By July 26, it had three operations officers and eleven scientists, most of whom were commissioned officers. Pash asked for some CIC detachments to increase the mission’s capabilities and, after much co-ordination with many headquarters, these agents were eventually assigned to him. At the same time, Goudsmit was pressing for additional scientific people to handle the ever-growing load that was being placed upon Alsos as its reputation in the European Theater grew. We got them with the help of the OSRD, and by August 31, the mission had grown to seven operations officers and thirty-three scientists.
Throughout the European campaign, as far as atomic efforts were concerned, Alsos members had the tremendous advantage of knowing where they were going and whom and what they were seeking. When they landed on the Continent, they had in hand the fruits of Calvert’s labors, in the form of a comprehensive list of intelligence “targets”—the names of key individuals, where they worked and where they lived; and the location of the laboratories, workshops and storage points, and other items of interest to us. At the head of the list was the famous French atomic scientist, Frederic Joliot-Curie (later High Commissioner of Atomic Energy for France), and his equally famous wife, Irene Curie, the daughter of Madame Curie, discoverer of radium.
On August 9, 1944, advanced elements of the Alsos mission landed in France and entered Rennes. In going through the laboratories of the university there, they discovered a number of catalogues and other papers that provided information pointing to possible future targets.
Pash’s first efforts in France were unproductive. Joining the Eighth Army Corps with one CIC agent, he tried to reach and search Joliot’s summer home, as well as the homes of his colleagues, Pierre Auger and Francis Perrin, near l’Arcouest. Although the surrounding area was heavily mined, Agent Beatson led the way into Perrin’s house on August 11, only to find that it had been completely stripped of furniture and personal effects and provided no information of any value. In trying to reach Joliot’s house, the party came under small-arms fire from snipers and prudently abandoned the effort. When resistance finally ceased on the twelfth, the house was searched, but without any worth-while results.
Alsos’ work on the Continent began in earnest on August 23 when Pash, Calvert and two CIC agents joined the leading elements of the Twelfth Army Group moving toward Paris. Learning that the entry into Paris would probably be from the south, the group joined the 102nd Cavalry Group, but when that unit was held up at Palaiseau, they moved cross-country and joined the 2nd French Armored Division, which had been chosen to lead the liberating forces into Paris.
They reached Joliot’s house in the suburbs of Paris on the twenty-fourth. Servants there informed them that the professor was in Paris, probably at his laboratory. So, without further ado, they telephoned the laboratory and, finding Joliot away at the time, told one of his assistants that they would like to see Joliot, they hoped, in a day or two.
On August 25, they reached Paris, at the Porte d’Orleans, ahead of the French troops, and waited there for about half an hour until General LeClerc arrived with his armored division. The General led the triumphal entry, at 8:55 that morning, but tucked into the column, directly behind the first tank was an American jeep containing the first representatives of the U.S. Army: Pash, Calvert and two other Alsos agents. The sniper fire became a bit unpleasant, particularly as the open jeep was a much more attractive target than the well-buttoned-up tanks, so Pash’s group left the column. They soon returned, however, finding that an exposed jeep was better off in a tank column than out of it. Later, toward evening, they broke off again, and succeeded in reaching Joliot’s laboratory. There, on the steps of the university, they found Joliot and some of his staff, all wearing FFI arm bands. That evening they celebrated the liberation with Joliot by drinking some champagne he had reserved for the occasion. The American soldier’s staff of life, the K ration, served as the hors d’oeuvres. In keeping with the scientific surroundings, the champagne was drunk from laboratory beakers.
In the course of their conversation with Joliot, the names of two of his former colleagues came up: Hans von Halban, born an Austrian in Leipzig and later naturalized as a French citizen, and Lew Kowarski. Both men had left France for England in June of 1940 and had been working in the British Tube Alloys Project in Canada. Joliot immediately surmised that there was some connection between them, Pash and Calvert, and the uranium problem. They did not openly tell him at first what they wanted of him. However, after an hour’s conversation, Joliot willingly told them just what they wanted to hear: that it was his sincere belief that the Germans had made very little progress on uranium and they were not remotely close to making an atomic bomb. He said he had refused to perform any war work for the Nazis and had forbidden them to use his laboratories for such purposes. However, after the occupation commenced, he said he did allow two German scientists to move into his laboratory to continue academic work on nuclear physics. He added that he talked with them frequently and clandestinely checked their work at night after the laboratory was closed, thus keeping constant surveillance on their activity. How true this all was we never knew.
Arrangements were made immediately for Joliot to be interviewed in Paris by Goudsmit on August 27, and two days later, Calvert flew back to London with him. There interrogations were conducted for several days by Michael Perrin, assistant director of Tube Alloys, and others of the British staff, as well as by Goudsmit. At first Joliot, who claimed to have been actively engaged in the French underground resistance movement, seemed quite willing to discuss the scientific activities in his laboratory. Although he added little to the knowledge we already possessed, he did clarify a few doubtful items. The College of France, which was Joliot’s laboratory, owned a cyclotron, and a number of German scientists of interest to the MED had spent varying lengths of time there operating it. Among them was Professor Erich Schumann, who headed the German Army Research conducted by the Ordnance Department and who, during the war, served as the personal adviser on scientific research to Field Marshal Wilhelm Keitel. Schumann was credited with initiating work on the German uranium project, although by the end of 1942 his responsibilities had been transferred to the Reich’s Research Council. Another visitor to Joliot’s laboratory was Dr. Kurt Diebner, who in 1939 had served as Schumann’s right-hand man and who had continued nuclear research under the Reich’s Research Council. Then there was Professor Walther Bothe, an outstanding German nuclear experimentalist in the physics laboratory of the Kaiser Wilhelm Institute for Medical Research. Dr. Abraham Essau, who until early 1944 was in charge of physics under the German Ministry of Education in the Reich’s Research Council, had made a number of visits to Paris. Essau had been president of the Ministry’s Bureau of Standards until January, 1944, when he was replaced as Plenipotentiary for Nuclear Physics by Walther Gerlach. There was also Dr. Wolfgang Gertner, an able German scientist who, before the war, had been associated with Ernest Lawrence in the United States. Gertner was an outstanding German authority on cyclotron operations. Joliot’s other visitors had included Dr. Erich Bagge, a member of the Kaiser Wilhelm Institute, who specialized in isotope separation, and Dr. Werner Maurer, an experimental physicist engaged in nuclear research.
Joliot consistently maintained that he had acquiesced in the Germans’ use of the cyclotron with the distinct understanding that its use would not be of direct military assistance to their war effort. There was no independent evidence that this condition was made. There may have been a promise made to him by some of the German scientists, or they may have said that there appeared to be no military possibilities that could result from the use of the cyclotron, but I never found any real proof of Joliot’s contention. Certainly, his subsequent behavior—and I shall come to that shortly—gave us room for doubt.
Bothe appeared to have been more or less in charge of the German scientists who visited the Paris laboratory. Apparently he had been rather high-handed in his treatment of Joliot, who showed no love for him. Joliot expressed the opinion that Bothe knew a great deal about our work in the United States.
We considered Joliot to be a competent judge in this matter, for he was in contact with von Halban and Kowarski, who, as I have said, were associated with the Canadian National Research Council, working on Canada’s part in our joint project. We understood that von Halban had written his mother, who lived in Switzerland, that his Canadian work was the same as his prewar activity. That information had been relayed to Joliot. By this and similar means, he had been able to assemble considerable knowledge of our efforts—knowledge that he tried with little success to explain away.
Conversations with Joliot did reinforce our more recent surmises that” the Germans were not so far along in the development of an atomic weapon as we had originally feared. Nevertheless, we felt he was evasive about his contacts, and we placed little faith in his statements. In any event, if what he said were true, his contacts in Germany and with German scientists were not too strong. He said he had only meager knowledge of the steps taken by the Germans in the field of nuclear fission, and we had no reason to doubt his contention.
And so the Alsos investigators were left once more without any positive information on enemy progress in nuclear research and development. On the other hand, we fully appreciated that the Germans must be embarked upon some sort of program, or they would not have found it expedient to use Joliot’s laboratories.
In mid-September, after Paris was securely in Allied hands, Alsos headquarters was set up there, the mission’s London business being turned over to Calvert. At the same time, through the link-up of the American Third and Seventh Armies, it was possible to reduce Alsos activities in the Mediterranean area and to reinforce their efforts in northern France and the Lowlands.
The mission was organized at this time into a number of groups of officers and CIC agents, who were to secure vital targets as they were seized by the assault elements of the advancing Allied armies. The good working relationships with the several high headquarters in the theater, which Pash and Calvert had established before the start of the campaign, ensured the mission whatever combat support it might need to reach its targets. And, as always, Calvert’s group in London was invaluable in supplying it with the data it needed in order to operate—names, places, installations. Long before the invasion of France we had begun to get the reliable information that inevitably develops when intelligence officers keep plodding through the drudgery of examining thousands upon thousands of uninteresting reports.
The most difficult problem that Calvert’s intelligence group had to tackle was to find out where Hitler was hiding his atomic scientists. They knew, as everyone did, that before the war the Kaiser Wilhelm Institute in Berlin had been a focal point for all atomic physicists and atomic research, not only in Germany, but in all of Europe. It was there that Otto Hahn and Fritz Strassman had carried out their startling experiments. It was also the home of Max Planck, the internationally famous atomic scientist.
As the war drew on, however, and the bombing of Berlin was stepped up, we had learned from both aerial reconnaissance and a Berlin scientist, who got word to us through the Norwegian underground, that research on uranium had been moved, presumably to a safer location, but where he did not know. Until that time, our intelligence had come in on a fairly regular basis, but then it virtually ceased. We were confronted with the problem of finding out where the Kaiser Wilhelm group had moved and what they were up to.
The first information had trickled through in the summer of 1943. It seemed so innocuous that we did not appreciate its full import until much later. It was in the form of a report from an ungraded1 Swiss informant, received by the British Secret Intelligence, stating that a certain Swiss scientist, who was allegedly pro-Nazi, was aiding in the development of an explosive a thousand times more powerful than TNT. His experiments and research were being conducted in the greatest of secrecy in an unused spinning mill in Bisingen, Germany. Inasmuch as Allied Intelligence was receiving hundreds of reports of this nature daily, and coupled with the absence from this one of any telltale words or phrases, such as uranium, atoms, heavy water, cyclotrons or the like, Calvert catalogued this item but did not attach immediate importance to it.
Next, in the fall of 1943, American censorship had intercepted a letter from a prisoner of war in which he mentioned that he was working in a “research laboratory numbered ‘D.’” The letter was postmarked Hechingen, Germany, which is three miles north of Bisingen, in the Black Forest region of Germany, where many secret German projects had been moved. But again the report was so scanty that one could hardly assume that Germany’s atomic research was being carried on in these outwardly sleepy little villages.
It.was not until the spring of 1944 that Calvert received his first solid information. Then the OSS reported from Berne, Switzerland, that a Swiss scientist and professor had said that Dr. Werner Heisenberg, an internationally famous nuclear physicist and one of Germany’s top atomic scientists—if not the top—was living near Hechingen. We knew from other intelligence that Heisenberg was working on the uranium problem. With this new bit of information, Calvert knew that he had found the hiding place of Hitler’s top atomic scientists. From that moment on, his group worked feverishly to learn all they could about the Bisingen-Hechingen area. Almost simultaneously with the Berne report came a message from one of Britain’s most reliable agents in Berlin that other top-ranking atomic scientists had been seen in this same area.
Calvert’s next big problem was to try to penetrate the area. To do that he would have to get somebody who knew it extremely well. British Intelligence located a vicar living in England who before the war had been Vicar of Bisingen. He was able to pinpoint and identify buildings and factories for us. He also pointed out buildings that had housed spinning mills. At the same time Calvert sent a very reliable and able OSS agent, Moe Berg, the former catcher of the Washington Senators and Boston Red Sox, and a master of seven foreign languages, into Switzerland to prepare for a surreptitious entry into the Hechin-gen-Bisingen area. While Berg was in Switzerland, he picked up additional information and, passing himself off as a Swiss student, even attended a lecture given by Heisenberg, who had been granted permission to travel outside Germany to deliver this one speech. When I heard of Calvert’s plan for Berg to go into the Hechingen-Bisingen area, I immediately stopped it, realizing that if he were captured, the Nazis might be able to extract far more information about our project than we could ever hope to obtain if he were successful. Instead, we continued to send agents into Sweden and Switzerland to see what they could find, and, at the same time, intensified our search for prisoners of war who had recently been in the area.
Starting in July, Calvert put the Bisingen-Hechingen area under constant air-photo surveillance. The pilots who flew these missions were never told of the nature of the suspected targets, lest they be interrogated in the event of a crash landing. At first our aerial reconnaissance produced nothing new. Then in the fall of 1944, we had our biggest scare to date. After one aerial sortie it was observed that near the town of Bisingen a number of slave labor camps had been erected with incredible speed. Ground had been broken and a complex of industrial sites had mushroomed within a period of two weeks. Railroad spurs had been constructed; mountains of materials had been moved in; power lines had been erected; and there was every indication that something was being built that commanded the utmost priority. Aerial interpreters, intelligence officers, our own technicians and scientists were all baffled after studying the photographs. Nobody could offer any sensible explanation of this new construction. All we knew was that throughout the past year we had been getting reports that this area was housing Germany’s top atomic scientists. The only thing upon which we could all agree was that whatever the construction was, it was unique. Naturally the first question that came to our minds was whether this was the start of Germany’s “Oak Ridge.” If it was, we did not want to bomb it immediately, since that would only drive the project underground and we would run the risk of not finding it again in time. Yet we could not let construction progress too far, particularly since this was just at the time when it was thought that the Germans might withdraw to the Black Forest and make it a redoubt area. Fortunately our anxiety was short-lived, and the fear of a German atomic plant was dissipated almost as quickly as it had arisen, when some British mining experts recognized that what we had been observing so closely was nothing more than a new form of shale-oil-cracking plant.
When Alsos moved northward into the Lowland countries in September, Pash entered Brussels with the advanced elements of the mission. There he set about securing Union Miniere’s offices and records. From these, he soon determined that all our previous information about the disposition of the Belgian ore had been correct.
Mr. Gaston Andre, in charge of uranium at Union Miniere’s main office, gave us much valuable information about the movement of uranium from Belgium during the German occupation. Before the war, when Union Miniere was the world’s leading supplier of uranium and radium, a number of German firms had purchased uranium products for normal peacetime uses, as well as for retrading purposes. The shipments involved in such transactions normally consisted of less than a ton per month of assorted refined materials, but since June, 1940, orders from a number of German companies had increased spectacularly.2
A preliminary study conducted by Union Miniere indicated that a quantity of material was still in Belgium. Part of it was ready for shipment, but probably had not yet been removed. When I learned of this, I immediately sent Furman back to Europe with instructions to locate and secure the material. He and Pash conferred with General Bedell Smith, who arranged for the British 21st Army Group to support Alsos in its recovery operations, without revealing to the British the name or purpose of the material being sought. The area where they expected the ore to be was then in the front lines of the British sector and under light sniper fire. Pash and two of his agents hunted for it from September 19 to 25 before they finally found it. The captured ores amounted to sixty-eight tons, which were placed under joint American and British control and removed from Belgium to the United States by way of England.
Information obtained in Belgium led to further investigations in Eindhoven, near Antwerp, where we learned that in May of 1940, nine cars containing approximately seventy-two tons of uranium ores had been shipped out to Le Havre, France, ahead of the German invasion. Apparently, the Germans had seized two of the nine carloads at Le Havre, while the remainder were rerouted to Bordeaux. I instructed Alsos to obtain clearance from Supreme Headquarters, and then to locate this material and secure as much of it as possible. Pash and Calvert concentrated at first on an area in the vicinity of Perigueux, France, and finally in early October expanded their search to include much of southwestern and southern France. They were greatly hindered in their search by the presence of several thousand German troops, who had been cut off south of the Loire River by the Seventh Army. Eventually, they found thirty tons of the missing ore in Toulouse, but the remaining forty-two tons eluded us.
Calvert had by then determined where almost all of the Union Miniere ore in Germany was located and asked permission to make plans to go behind the German lines to get it. I denied his request, for I thought that any such attempt would be doomed to failure, and, what was more important, it would alert the Germans to the fact that we considered the ore to be of such value that we would take great risks to obtain it.
Throughout this stage of the campaign, one Alsos team had been visiting stockades to question prisoners of war, giving special attention to men who had served with labor battalions in Germany. They turned up a number of good leads. One took them, in November, 1944, to the abandoned office of a Paris company that handled rare earths. It had been taken over by Auer-Gesellschaft, the well-known German chemical firm, and was run by a Dr. Ihee whose trail we had crossed earlier in Brussels. During his frequent absences from the Paris office, his business was conducted by his representative, a Dr. Jansen, and his private secretary, Use Hermanns. Among the few items of intelligence found in the Paris firm’s office was a list of registered mail, which indicated that one of the last outgoing letters was addressed to Miss Hermanns at Eupen. This town was in American hands by then and the investigation was pressed until both Miss Hermanns and Jansen were found. Although we got very little useful information from Dse Hermanns, documents found among Jansen’s effects indicated that both had recently visited Ihee at Oranienburg near Berlin, and that Jansen had also recently visited his mother at Hechingen. Since we had previously learned of thorium deliveries to Oranienburg, and considering our vital concern with Hechingen, our interest was greatly aroused. Yet Jansen, it turned out, had very little information about either place. He told us that Ihee was in charge of the rare earths department of Auer, and that his main office was at Oranienburg, but he appeared to have only a superficial knowledge of what Auer was producing. He said that Ihee had visited Paris about once every six weeks and in the meanwhile traveled extensively in southern France, for what purpose he did not know, though he did speak of a search for monazite. As for Hechingen, Jansen knew only that it was located within a zone that had been restricted for military reasons; but otherwise he knew of no activity there.
Jansen’s information, though unremarkable, did focus our attention on Ihee, whom we eventually caught up with. It also strengthened our suspicions regarding Oranienburg and Hechingen.
As the American armies approached the city of Strasbourg, we made careful plans. The main items of interest to us there were the personnel and facilities at the University of Strasbourg. The Nazi authorities had always treated this as an entirely German institution; it was staffed throughout by Germans and the faculty was working on at least a part-time basis on German war projects. Pash maintained close liaison with the Strasbourg T-Force Command, a unit of the Sixth Army Group, to ensure that the Alsos advanced party would be among the first to enter the city and to make certain that the T-Force knew what the Alsos objectives were.
On November 25, 1944, the advance party from Alsos joined the T-Force in Strasbourg, took over the university laboratories and the offices and residences of all target personnel, and by the end of November had located, interned and placed under guard seven physicists and chemists, all of whom were German citizens.
The scientific members of Alsos began a detailed study of all captured objectives as soon as the military situation permitted. They obtained various leads and items of information concerning medical research, aircraft and naval matters. In the field of our particular interest, they found four faculty members whose backgrounds and occupations warranted their separation from the other internees, for possible transfer to the United States. Subsequent questioning, however, failed to show that any of them had engaged in direct research on nuclear weapons and their answers provided very little worth-while information.
One of the men in whom we were particularly interested was Professor C. F. von Weizsäxcker. We had thought he was with the University but though we found his house, he appeared to have fled before the entry of the Allied forces. In contrast to the meager information obtained from the German scientists themselves, the documents and personal correspondence found in their offices, laboratories and home files provided us with much intelligence of real value.
While this information was in itself unclassified, it was possible, through the notes of meetings, fragments of computations, descriptions of experiments and vague hints in personal correspondence, to assemble a revealing picture of the German nuclear research program.
This operation at Strasbourg was by far the most successful that Alsos had conducted up to that time. The information gained there indicated quite definitely that Hitler had been apprised in 1942 of the possibilities of a nuclear weapon. Nevertheless, all evidence from Strasbourg clearly pointed to the fact that, as of the latter part of 1944, the enemy’s efforts to develop a bomb were still in the experimental stages, and greatly increased our belief that there was little probability of any sudden nuclear surprise from Germany.
I still wanted further confirmation, however, for Strasbourg also established that the enemy was definitely engaged in a program of nuclear energy research and indicated the places in Germany where that work was going on. We were also fairly sure of the personnel and locations involved in the industrial effort supporting this program. After all these indications had been analyzed by both the MED and the OSRD, Alsos was in possession of a dependable guide for its subsequent operations in the German homeland.
The German Ardennes offensive (the Battle of the Bulge) caused us some real consternation when, for a brief period, it appeared that the Allied forces might have to evacuate Strasbourg temporarily. This created a very serious problem for us, for it inevitably would have compromised Alsos for future operations within Germany. Fortunately, evacuation did not become necessary.
1 A term used to indicate “unknown reliability,” in military intelligence.
2 Auer-Gesellschaft, a well-known German chemical firm, which had not been one of Union Miniere’s customers before the war, suddenly became an outstanding consumer of uranium products, and had bought about 60 tons of refined material from them during that period. The next large German shipment was in November, 1941, and consisted of about 9 tons of uranium products to the Deutsche Gold und Silber Scheideanstalt (Degussa), an Auer subsidiary. Degussa had been a prewar user of small amounts of uranium for making ceramic colorings. It had an outstanding reputation in the field of metal refinement.
During June of 1942, unusually large amounts of uranium products had been shipped to Roges GMBH, a wartime trading agency which was considered to be directly connected with the German Ministry of Trade and Finance. The uranium products ordered by Roges consisted of about 115 tons of assorted refined and partially refined materials. In addition to these, they obtained 610 tons of crude materials, 17 tons of uranium alloys and about 110 tons of impure rejects from the refining process. In January and May of 1943, they obtained 60 tons and 80 tons of additional refined products.