him complaining “about being continuously overworked and homesick.” He was married, with twin children, Victoria and Pavel, born four months after his arrival in the US, and Gold would find him not complaining but optimistic; John and Sam, Gold remembered, “spoke with great pride of their wives and their children, and would elaborate on their great plans for the future of the young ones.” When discussions among the Allies began in San Francisco “which led to the formation of [the United Nations], I can recall the enthusiasm with which Yakovlev discussed the affair. We both thought it was such a great thing.”
Fuchs and Gold met again in February, on the northwest corner of 59th Street and Lexington Avenue. They walked east toward the Queensboro Bridge, “the intention in my mind,” says Gold, “being that we would walk across the bridge and into Queens.” They found the bridge closed to foot traffic and walked uptown along First or Second Avenue instead, possibly as far as 75th Street. It was “anything but an exclusive area,” Fuchs remembered; Gold recalled “several passages on the dark deserted streets.”
At this second meeting Fuchs told Gold about the Manhattan Project work on isotope separation. Gold was captivated. For years he had studied developing a process for recovering valuable compounds from industrial waste gases using thermal diffusion, the type of isotope separation with which Otto Frisch had experimented at Birmingham in 1939 that had led him to conclude that U235 could be separated from U238 to make an atomic bomb. “That is my baby, that is my dream,” Gold exclaimed in 1950 when FBI agents asked him about his interest in thermal diffusion; he told them he had written a dissertation on the subject, a claim they later confirmed. So he was surprised when Fuchs seemed not to know about the process:
Klaus knew of only two methods for the separation of the isotopes from uranium, that is, methods as were being pursued here in the United States, and… these methods were, (1) The gaseous diffusion process, (2) The electromagnetic separation process.
It was Harry's chance to impress a man he considered to be a “genius.” He made bold to do so: “I… mentioned to Klaus the possibility of the use of thermal diffusion as a means of separating isotopes, but… Klaus… brushed this aside.” Gold must have been crushed. Fuchs could be arrogant as well as insensitive; in fact, when problems with the gaseous-diffusion plant that Fuchs was helping design delayed its full operation, Groves would jury-rig a thermal-diffusion plant of physicist Philip Abelson's design which would process a significant portion of the uranium enriched for the Little Boy uranium gun bomb exploded over Hiroshima; without thermal diffusion there would have been no uranium bomb ready to use in August 1945.
Fuchs emphasized to Gold then and later that Manhattan Project scientists, as Gold recalled, “worked in extremely tight compartments, and that one group did not know what the other group was doing. This I can verify by the fact that he told me that he thought that there was [the] possibility of a large-scale installation for isotope separation projected for future development somewhere, he thought, down in Georgia or Alabama. This, of course, later turned out to be Oak Ridge.” And was, of course, the very plant that Fuchs was helping design.
Gold “made good mental notes of such data,” he would testify, and after the meeting “… at the first opportunity I put this material in writing, and later handed it over to John.” John sent the information back to Moscow Center in coded cables; Fuchs's code name in the cables was “Rest.” The cables went out over commercial telegraph lines, which made it possible to intercept them. After the Japanese surprise attack on Pearl Harbor on December 7, 1941, and US entry into the war, the US State Department had promoted a “drop copy” program whereby the cable companies held up message transmissions long enough to copy them, ostensibly for the US Office of Wartime Censorship. The copies went through the censorship office to the Army security agency, where the FBI had access to them. Soviet espionage cables were coded on one-time pads, however — five-unit ranks of random numbers on pads of paper, used only once, that matched pads kept in Moscow — so that without access to the code pads they were effectively indecipherable; thousands of such coded Soviet wartime cables piled up at Army security, Fuchs's ongoing disclosures among them.
Fuchs met Gold for a third time in March 1944 on Madison Avenue in the 70s. “It was still quite cold and we both wore overcoats,” Gold recalled. “… We immediately turned into one of the dark deserted sidestreets toward 5th.” For the first time, Fuchs passed Gold documents. To reduce the risk that both might be apprehended together, it was standard practice between Soviet agents to separate immediately after a document transfer. “The whole affair took possibly 30 seconds or one minute,” Gold testified, “and I immediately walked ahead of Klaus and down 5th toward 57th Street and 6th Avenue, where approximately 15 minutes later I turned over the information to John.”
Fuchs and his colleagues, particularly Rudolf Peierls, were working on a series of papers for Kellex, designated the MSN series, laying out gaseous-diffusion theory. During the period when Fuchs was based in New York, the British completed nineteen papers in the MSN series. Of those, Fuchs personally wrote thirteen. “Two or more MSN papers,” Fuchs testified somewhat inaccurately in FBI paraphrase, “were passed to Raymond by him at each of the approximately 5 meetings held after the first meeting.” To evade security, Fuchs simply took advantage of the trust the Manhattan Project accorded him:
I, with other scientists, prepared certain highly confidential and classified documents… referred to as the MSN Series… I would first prepare a draft… [This draft] would be routed for duplication — In all instances, when I prepared the draft a proof copy and the original draft would be returned to me. Each of the duplicated copies was numbered for control and security purposes, due to the highly confidential character of the contents. I would personally retain the original draft, which most of the time I had prepared in longhand, and I personally furnished all of the drafts of my own composition directly to the individual known to me as Raymond… These documents were at times folded and at other times in package form and were delivered by me personally in groups of one or more at most of the… prearranged meetings, after the initial contact meeting which I had covertly with Raymond in New York City during 1944.
From this point on, Fuchs's and Gold's accounts of their meetings diverge. Gold remembered dinners together and personal confidences that represented, he said, at least “a deviation from the rules.” Fuchs remembered strict compliance and businesslike formality; confronted, later, with Gold's testimony of bonhomie, the emigre physicist rejected testimony and eager witness both with withering contempt:
[Fuchs] advised that there would have been no occasion for any meeting except to deliver written information since the knowledge and background of Raymond was insufficient to enable him to understand technical details and his lack of scientific knowledge of the type necessary to understand the problems on which Fuchs was working would have made it very unlikely that [Fuchs] would have arranged any meeting with Raymond after the first for any purpose other than to deliver information in writing to him.
But the volume of related information that Fuchs testified he furnished Gold orally implies extended conversation: “the manpower employed by Kellex and the nature of the work being performed by the British Mission and all that he knew concerning personnel and general activities in the Manhattan Engineer District… The identity of the officers and the high-ranking scientists… He also discussed some of the personnel orally.” Gold also reported confidences about Fuchs's family which the chemist could not easily have learned from any other source. Fuchs was a bachelor alone in a strange country, unable because of the double life he was leading to confide in colleagues, penny-in-the-slot. Under similar circumstances in England he had confided similarly in Sonia. He was both “stuffy” and “repressed,” as Gold accurately characterized him. In repudiating Gold, Fuchs sounds like someone angered to hear his confidences betrayed and incensed that a mere industrial chemist, a bag man, would presume. (The question is important. Later, when Gold was exposed as a courier and testified for the US government against Americans accused of spying, there were attempts to discredit him as a fantasist, a lonely bachelor who invented tales and connections to thrust himself into the limelight. But in fact, allowing only a little for the vagaries of recollection across fifteen crowded years of espionage work, Gold's remarkably detailed memories of events almost always prove accurate wherever they can be checked.)
So at their fourth meeting, in the Bronx, in April, Gold recalled, “we went for a walk partly along the Grand Concourse… during which time we discussed the next meeting… at which a second transfer of information was to take place… After this I took Klaus to dinner, it was a wet and somewhat chilled night for April, and as I recall, he had a bad cough, and I did not wish to expose him to the elements any more than was necessary… We had a dinner
