Operation Epsilon

From June to December 1945, ten leading German scientists, variously connected with Atomic Energy research, were detained, incommunicado, at Farm Hall, Godmanchester, near Cambridge, England. The scientists detained were Erich Bagge, Kurt Diebner, Walther Gerlach, Otto Hahn, Paul Harteck, Werner Heisenberg, Horst Korsching, Max von Laue, Carl Friedrich von Weizsacker and Karl Wirtz. Their conversations were secretly recorded by British Intelligence.

Background
Throughout the work on the Manhattan Project directed by Major General Leslie R Groves, those engaged saw themselves as in a race with the Germans who had a head-start since nuclear fission had been discovered by Hahn in Germany at the end of 1938.

The ALSOS mission, under the scientific leadership of Samuel A Goudsmit, was charged with following closely behind the Western Allied invading forces in 1944 to locate and seize personnel, documents and material concerned with the German Atomic Bomb programme. Though the evidence collected by November 1944 was enough to convince Goudsmit that there was no German Atom Bomb in the making, there continued to be many, particularly in America, who would not believe it.

So the mission continued with much the same target, at least for Intelligence purposes. These ten individuals were selected by Goudsmit. Among those picked up, mostly at Hechingen, by an Anglo-American raiding party, which had made its way through a gap in the crumbling German front, under the leadership of Colonel Boris T Pash, the principal military officer of ALSOS. Hechingen is on the Eastern edge of the Black Forest. It was there that the greater part of the Kaiser Wilhelm Institut fur Physik, in particular with its uncompleted nuclear reactor pile, had been relocated after being bombed out from Berlin.

It was R V Jones who pointed out that Farm Hall in England, which belonged to the British Secret Service, would be a suitable place to house them. He also suggested that microphones should be installed there before they arrived. This had become standard practice with senior prisoners-of-war. Experience had shown that their private conversations could be more revealing than interrogation.

1 May 1945
I (Major T. H. Rittner) received at HQ from Lieut. Cdr. Welsh instructions to proceed to Rheims (France), to report to G2 SHAEF (Supreme Headquarters Allied Expeditionary Force) and collect a party of German Scientists. A Chateau at SPA (Belgium) had been prepared for their detention.

A number of distinguished British and American Scientists would be visiting them in the near future. My instructions were that these Germans were to be treated as guests.

No one, repeat, no one, was to contact them except on instructions from HQ.

2 May 1945
I proceeded by air to Rheims and reported to SHAEF where I was informed that the Chateau at SPA was no longer available. The party was to be held at Rheims at 75 Rue Gambetta until other arrangements could be made.

Arrangements had been made to draw "American A Rations" ready cooked. A staff of two British Orderlies and an American cook had been provided by SHAEF in addition to the necessary guards.

The same evening, the following arrived at 75 Rue Gambetta, escorted by Major Furman, US Army : Prof. Hahn, Prof. Von Naue, Dr. Von Weizacker, Dr. Wirtz, Dr. Bagge, Dr. Korsching. Prof. Mattauch, whom I had been told to expect was not among the party.

The professors were friendly and settled down well. They expressed appreciation of the good treatment they were receiving. A very pleasant atmosphere prevailed. At my request, they gave me their personal parole not to leave the house or that portion of the garden which I alotted to them.

5 May 1945
The professors were by this time beginning to get restive. They were particularly worried about their families. They asked permission to write letters. After referring the matter to HQ and obtaining sanction, the letters were written. After being censored by me, they were handed to General Strong's secretary at SHAEF for transmission.

7 May 1945
SHAEF informed me that arrangements had been made to accomodate the party at Versailles and HQ had agreed to the move. A Dakota was put at our disposal. The party took off at 1700 hours in the expectation that at last the long awaited contact with their British and American colleagues was about to take place.

On arrival at Versailles, I reported to G2 SHAEF and found that the party was to be accomodated in a detention centre known as "Dustbin" at the Chateau du Chesnay. This centre had been set up for the purpose of interrogating German Nazi Scientists and Industrialists. The conditions were most unsatisfactory from my point of view, as complete segregation was impossible and there was great danger of undesirable contacts being made with the professors. In addition, only camp beds were provided. There was scarely any other furniture. The food was the ordinary PW rations. It was obviously impossible to carry out my mission in these surroundings but I was able to pacify the professors who accepted the situation with as good a grace as possible. I promised to do my best to get them moved as soon as possible. The Camp Commandant did his best to make them comfortable.

8 May 1945
In spite of the general holiday atmosphere at SHAEF and in London consequent upon the declaration of VE Day (Victory in Europe Day), I managed to contact HQ by telephone and explain the new situation. He told me to contact Major Furman, US Army, in Paris and try and make other arrangements through him. This I did and we decided to try and get the party back to the rue Gambetta at Rheims.

9 May 1945
Major Furman informed me that he was arranging for us to return to Rheims. In the meantime, the following Germans were to join the party : Prof. Heisenberg, Dr. Diebner.

The situation at the Chateau du Chesnay was becoming more and more difficult as the professors were highly indignant at being treated as "war criminals" as they put it.

In spite of the fact that other German Scientists were in the house and were being interrogated by British and American Officers, I was able to prevent the identity of my party being revealed. I had refused to submit a nominal roll or to allow any contact with them. Dr. Robertson, Scientific Advisor to SHAEF did, however, see Prof. von Laue out for exercise and spoke to him. But I was able to persuade him to break off the conversation and he accepted the situation well.

10 May 1945
The professors were becoming more and more restive. They begged me to contact Prof. Joliot in Paris, whom they assured me would help them. This request was of course refused. I told them they must have patience and that everything possible was being done for them. In order in some way to alleviate conditions, I took them in parties by car to Versailles to see gardens and Palace.

On one occasion, a guide asked for their identity cards in order to visit the Hall of Mirrors. We left the premises hurriedly, having pleaded a previous engagement.

11 May 1945
It was now clear that the difficulties which had arisen were due mainly to an order issued by the Supreme Commander stating that no preferential treatment was to be given to any captured German nationals. This order was given after reports had appeared in the press describing the good treatment being meted out to Reichsmarschal Goring.

General Strong refused to agree to my party returning to Rheims. But, arrangements were made by MIS (Military Intelligence Service), on the instructions of Brig. General Conrad, to accomodate the party for a short time at a villa at Le Vesinet, near St. Germain. The professors were overjoyed at the prospect of leaving what they called the concentration camp. After I had inspected the villa, I left Versailles with the party in command cars on the evening of the 11 May after informing HQ by cable of the arrangements which I had made.

The Villa Argentina, 89 Alee du Lac Inferieure at Le Vesinet was a large house standing in its own grounds. MIS provided a guard. They arranged for us to draw "American B Rations" in a semi-cooked condition from their mess. They also supplied us with canteen goods. During our stay at Le Vesinet, MIS gave me every possible assitance.

The professors were delighted with their new surroundings. The old atmosphere of cordiality quickly returned.

There was some trouble with the plumbing and electric light in the villa, which had been empty for some time. The professors all helped to remedy the defects. When outside help was necessary, such as on an occasion when the basement was flooded owing to a burst pipe, they were confined to their rooms whilst a very voluble and inquisitive French plumber dealt with the matter.

On the evening we arrived, Major Furman brought Prof. Harteck to join the party. As the party had now grown from six to nine, I asked the professors to renew their parole, which they did.

12 May 1945
As we could only have the use of the villa for a very limited period, I cabled HQ urging that efforts be made to bring the party to England, as it was obvious that it would not be possible to arrange accomodation on the continent suitable for carrying out my mission.

There was considerable speculation amongst the US troops and the French civilian population regarding the identity of the party. I was accused of harbouring Marshal Petain. A number of inquisitive people, including the owner of the villa who came post haste from Paris when he heard from the concierge that his house was being occupied, were dealt with. I was able to spread the story that my party consisted of active Anti-Nazis who were being kept by us for their own protection.

The information, inadvertantly let out by Major Furman, that French Colonial troops were still in occupation at Heichingen and Tailfingen caused consternation amongst the professors, who had been told that American troops would be taking over. Prof. Heisenberg asked permission to write a letter to his friend, Dr. Goudsmith of the US Army, who he believed was in Paris, asking him to get news of the families. I handed the letter to Dr. Goudsmit, who offered to do what he could. He subsequently gave me a letter from Prof. Heisenberg's wife, which I handed to him for which he was duly grateful.

17 May 1945
Brig. General Conrad came to the villa and I showed him over. He expressed his satisfaction with the arrangements that had been made and agreed that the "B" scale of rations should continue, although MIS wanted to reduce them to the "C" scale, which was that authorised for P.W. On the following day, however, the rations were cut without warning. I protested to Colonel FORD the C.O. of MIS who eventually agreed to restore the original scale.

The professors spent their time in Le Vesinet working in their rooms or sun-bathing in the garden. They developed a passion for physical exercise. Even the more aged Prof. von Laue and Hahn could be seen running solemnly round and round the garden at six o'clock in the morning. On Tuesdays and Fridays, they assembled in the common room to hear a lecture by one of themselves. I was able to supply them with books, technical journals, and games.

20 May 1945
I received a cable from VCSS informing me that Washington had been asked to agree to the professors being brought to England.

25 May 1945
MIS were pressing me to vacate the villa Argentina, which was urgently required to accomodate their own staff who were passing through Le Vesinet for re-deployment. I saw Colonel Ford and informed him that it was impossible for us to move until other suitable accomodation had been found. I assured him we were doing our best in this respect.

4 June 1945
A movement order was obtained from Colonel Ford. We left Le Vesinet at 1300 hours and arrived at the Chateau de Facqueval, Belgium at 2345 hours. There, only P.W rations were available. No provision had been made for a meal for the professors who had been travelling since midday. Fortunately, I had brought "American K rations" which we had eaten by the roadside.

5 June 1945
The routine at the Chateau was much the same as it had been at Le Vesinet. The weather being mainly fine, the professors spent most of their time in the garden. The guard troops had been provided with a piano and as they rarely used it, I persuaded them to give it to the professors. This instrument was in a very bad condition. A number of notes were missing, but it did not take them long to take the whole thing to pieces and repair it with improvised tools. I borrowed a local piano tuner's kit and they soon had it tuned. I also bought a wireless set, which proved a very welcome addition to the amenities of the house.

9 June 1945
The professors were very worried when they read in the newspapers that the Russians were extending their zone of occupation in Germany.

Dr. Diebner was frantic as it appeared that the town of Stadtilm, where his wife and son were, was to come under Russian Occupation. He begged me to get his wife and son moved into the British or American zone. In the meantime, Prof. Heisenber had told me that Mrs. Diebner had worked with her husband and knew about all his work and that of the others. He thought it would be unfortunate if she fell into Russian hands. I consequently cabled this information to HQ with the request for the family to be moved.

It was a great relief when I was able to inform him that his family had been moved to Neustadt Nr. Coburg. The receipt of this news moved him to such extent that he asked to be taken to Church although he admitted that he had had not been inside church for many years. I took him to the village church to mass the following Sunday.

14 June 1945
Professor Gerlach was brought from Paris to join the party. The professors were delighted to see their old colleague.

15 June 1945
By this time, the professors were again becoming very, very restive. They hinted to me that the time might soon come when they would take desperate measures to let the world know of their situation.

I had a long talk with Prof. Heisenberg. He told me that their main worry was the lack of information about their families. He also said that they suspected that their potential value was being judged by the documents found at their institutes. He said that these documents did not give a true picture of the extent of their experiments, which had advanced still further as a result of pooling of information since their detention. He begged for an opportunity of discussing the whole matter with British and American Scientists in order to acquaint them with their latest theories and work out scheme for future co-operation.

Prof. Heisenberg and Dr. Harteck suggested that Prof. Bonhoeffer of Leipzig, who they believed was at Friederichsbrunn in Ostharz, should be brought to join this party. They said he was an active Anti-Nazi who had worked with them and that it would be unwise to let him fall into Russian hands. The above information was passed to HQ by cable.

The professors again asked to be allowed to write to their families. I said I would try and arrange for the letters to be delivered. Letters were written. After censorship, which necessitated a lot of rewriting, these were handed by me to Lieut. Cdr. Welsh in London.

Lieut. Cdr. Welsh told me on the telephone that permission had been given for the professors to be brought to England. He asked me to come over as soon as possible to inspect Farm Hall.

17 June 1945
In order to get an air passage to the UK, I had to get myself temporarily attached to a British unit stationed at Brussels. I accordingly got myself attached to 21 Army Group. I got an authority from them and proceeded to London.

Lieut. Cdr. Welsh and I went to Farm Hall, where arrangements had already been made to install microphones. I had asked for such an installation from the day I took charge of the professors. We arranged with Colonel Kendrick to transfer the necessary staff of technicians from CSDIC (Combined Services Detailed Interrogation Centre) to man the installation.

26 June 1945
I returned to Belgium to complete the arrangements at Farm Hall. The professors received the news of the impending move to England with mixed feelings. On the one hand, they looked on it as a step forward in that they expected to meet their British colleagues. But on the other hand, England seemed much further away from home than Belgium.

Summary
The operation has been successful. The professors have been detained for over ten weeks without any unauthorised person becoming aware of their identity or place of detention. They have, with considerable difficulty, been kept in a good frame of mind.

The following are brief character sketches of the professors :
 * 01 : A man of the world. He has been the most helpful of the professors. His sense of humour and common sense has saved the day on many occasions. He is definitely friendly disposed to England and America.
 * 02 : A shy mild mannered man. He cannot understand the reason for his detention. He has been extremely friendly. He is very well disposed to England and America.
 * 03 : He has a very cheerful disposition and is easy to handle. He appears to be genuinely co-operative.
 * 04 : Charming personality. Has never caused any trouble. His one wish is to get on with his work. As he is a bachelor, he is less worried than the others about conditions in Germany.
 * 05 : A diplomat. He has always been very friendly and co-operative. I believe he is genuinely prepared to work with England and America, but he is a good German.
 * 06 : He has been very friendly and helpful. He is, I believe, genuinely anxious to co-operate with British and American Scientists, although he has spoken of going over to the Russians.
 * 07 : An egoist. Very friendly on the surface, but cannot be trusted. I doubt whether he will co-operate, unless it is made worth his while.
 * Y : Outwardly very friendly, but has an unpleasant personality. He is not to be trusted. He is disliked by all the others, except X.
 * X : A serious and very hardworking young man. He is unlikely to co-operate. His friendship with Y lays him open to suspicion.
 * Z : A complete enigma. He appears to be morose and surly. He very rarely opens his mouth. He has, however, become more human since his arrival in England.

The professors landed at Tempsford from Liege airport on the afternoon of 3rd July and were taken to Farm Hall by car together with four PW orderlies.

All the professors have renewed their parole to me in writing in respect of Farm Hall and grounds. I have warned them that any attempt by any one of them or by the orderlies to escape or to communicate with anyone will result in them all having their liberty considerably restricted.

Ordinary army rations are drawn for the professors, the officers, and troops. These are prepared by all by the PW cooks.

Microphones have been installed in all the bedrooms and living rooms used by the professors. This installation has enabled us to follow the trend of their thoughts.

The bi-weekly lectures are being continued. In fine weather, these take place out of doors.

6 July 1945
"I wonder whether there are microphones installed here?"

"Microphones installed? (laughing) Oh no, they're not as cute as all that. I don't think they know the real Gestapo methods. They're a bit old fashioned in that respect."

"They seem to be afraid that one might do something hostile to England, but they are hiding us from their own people. That is the amazing thing. If it had been the other way round, we never hid a foreign scientist in Germany, the other scientists all knew about it."

"It may be that the British Government are frightened of the communist professors. They say : 'If we tell Dirac or Blackett where they are, they will report it immediately to their Russian friends'. Kapitza and Comrade Stalin will come and say : 'What about the Berlin University Professors? They belong in Berlin'"

"It's quite possible they just don't want to say anything."

"Then of course they will have to wait until everything has been settled by the Big Three."

"They may not be able to say it openly because of Comrade Stalin."

"It is possible that the Big Three will decide it at Postdam, and that Churchill will come back and say : 'Off you go, the whole group is to return to Berlin' and then we'll be in the soup."

7 July 1945
"I think you should speak to the Commander and tell him we are very dissatisfied."

"Yes, and tell him in no uncertain terms that we are being wronged."

"You appear to have a certain influence on him. I think that you could achieve something with him."

"Well, I think I am more or less in his good books. I will point out to him that he has let ___ and ____ go on living happily in Germany, whilst we poor wretches have to let our wives and children starve."

"In the meantime, the British and American soldiers are looting everything at home."

"___ told him that we are living here like princes. But what use is that to us when we have no news of our families, have no idea what is to happen to us, and are out of touch with our work. Although we are well treated, we are nevertheless prisoners."

"These people have detained us firstly because they think we are dangerous. That we have really done a lot with Uranium. Secondly, there were important people who spoke in our favour and they wanted to treat us well. These two facts were mixed up. Now they have got into this awful political muddle."

"The decent thing for them to do now would be to say to us : 'It is not possible to come to a decision about you so quickly. What shall we do? Would you like to remain with your families for the time being or --?' But they don't do that, but prefer to keep us on ice. That's not nice of them. I don't believe it is due malice that they do nothing with us, but it is just that they cannot come to a decision about us."

"The damnable thing is that they won't let one have any say in what is to happen to one or one's family, or give any hopeful indication of what is going to happen."

11 July 1945
"If we want to continue working on our subject, we will certainly have to work together with the Anglo-Americans. No one has any money in Germany."

"If one is convinced that Germany will be occupied by the Russians for a long time and you work on the production of weapons for the English, the end result will be that you will make Germany into the future battlefield."

"I was once talking to ____ and ____ and I said : 'It would certainly be a clever move for anyone who is thinking of working in England to acquire British nationality as otherwise he would be shot if he fell into Russian hands'. They both agreed that one would have to do that. If one is taken to England, one many have to stay there."

16 July 1945
After reading in the newspaper that Lord Cherwell was attending the Postdam conference.

"That's the man who has had us detained."

"If Cherwell knew we were detained here, something would happen. He doesn't know. He would certainly speak to one and discuss what he should or could do."

"Things like that will certainly be discussed. I imagine they will decide at the Big Three conference which scientists are to go to Russia."

17 July 1945
"I would be glad if we could stay here."

"It would be a wonderful thing if we could become English."

"And then have nothing more to do with the Party again. I would willingly take an oath never to have anything to do with the Party again."

18 July 1945
"I could also imagine that they are afraid of the following. Assume that it became known that we are here. Some clever journalist would turn and would have a look at the place from the outside, see us playing all sorts of games in the garden, sun bathing, etc. The next day there would be a terrific article in the newspaper just like it was with Goering : 'German Nazi Scientists enjoying life in England. For lunch they have --' I could well understand that is the reason they want to keep it secret here. "

"I would imagine that we will be given more freedom the moment the Russians say : 'We agree, you will take over the scientists.' They are negotiating with the Russians as to who shall be handed over to Russia and who shall not. Presumably that is being discussed in Berlin now."

"If I were ever to land with airborne troops in England, I would have all the men arrested straight away and they would be separated from their wives for two years just to show them what it's like."

"I think there is a 90% chance of our getting back to Germany."

"Yes. I think that is most likely. At first I thought they would really be more interested in getting information out of us. But they don't do that."

"They will wait until they can do it better themselves. Then we will have to swear on oath not to talk about the thing, etc. And then perhaps they will pay each of us £500."

"Not on your life! We will have to pay for having been here."

21 July 1945
"I think there is a very good chance we will get back to Germany. There is a 25% chance we will get back before 1 December."

"The chance of getting back between 1 December and the end of next year, I would put at 70%."

"I think there is a 40% chance that we will never get back at all."

"I think there is a 15% chance that we will never to see our wives again"

"I can see no reason to assume that they want to treat us badly. But I can see a reason to assume that they don't want to have us in Germany, as they don't want us to pass our knowledge to other people."

"On the other hand, we may be shot. Not by the English, but by the people there. If one of us went to Hamburg University, some mad student might come and shoot one."

"I still feel very strongly that they are making an exception in our case, in that they are treating us better than most others. Therefore, I should say we will see our wives again even if we don't return to Germany. That would only be prevented if somthing unforeseen occured. Of course, one never knows. Something astounding may suddenly happen."

"That's what I think. I consider there is a 15% chance of that."

26 July 1945
"You must see that the situation is getting worse. Up to now I always hoped that the thing would come to end in some sensible way. But I have lost hope. That is the tragedy. I'm frightened. I'm reaching the end of my tether. (half sobbing)"

"About your family?"

"Yes. Of course that's one reason."

"That's been going on for three months and I'm supposed to look happy here. I shall go mad. I can't stand it much longer."

"You must stick it."

"I shall refuse to go downstairs. I shall eat nothing. I shall go on hunger strike."

30 July 1945
"I read an article in the Picture Post about the Uranium bomb. The newspapers had mentioned that such a bomb was being made in Germany. They will not let us go until they are absolutely certain that we will not fall into Russian hands or anything like that."

"The longer one is detained here and knows nothing, the more one gets into a state where one racks one's brain to discover what is going to happen. I fight against it and make jokes. Also, I don't take life too seriously in that I always look on the bright side of things."

"I would have been just the same in Germany. The day before I went away, I said to my wife, "I suggest we commit suicide." I had reached that stage then."

"My wife was like that sometimes. That is why I am worried whether she will hold out without news."

"I am becoming more and more pro-English. They do everything very decently. The Major takes great trouble."

"He takes great trouble and he would probably consider us ungrateful if we suddenly sabotaged everything. We can't do that."

"No, no, that's out of the question."

6 August 1945
Shortly before dinner on the 6th August, I (Major T.H. Rittner) informed Prof. Hahn that an announcement had been made by the BBC that an atomic bomb had been dropped. Hahn was completely shattered by the news. He said that he felt personally responsible for the death of hundreds of thousands of people, as it was his original discovery which had made the bomb possible.

He told me that he had originally contemplated suicide when he realised the terrible potentialities of his discovery. He felt that now these had been realised and he was to blame.

Later, he was calmed down and we went down to dinner where he announced the news to the assembled guests. As was to be expected, the announcement was greeted with incredulity.

"If the Americans have a uranium bomb, then you're all second-raters. "

"They are fifty years further advanced than we."

"We always thought we would need two years for one bomb. If they have really got it, they have been very clever in keeping it secret."

"I'm glad we didn't have it."

"Who is to blame"

"Hahn is to blame"

"I think it's dreadful of the Americans to have done it. I think it is madness on their part."

"One can't say that. One could equally well say 'That's the quickest way of ending the war'"

"That's what consoles me"

All the guests assembled to hear the official announcement at 9 o'clock. They were completely stunned when they realised that the news was genuine.

"They have managed it either with mass-spectographs on a large scale, or else, they have been successful with a photo-chemical process."

"Well I would say photochemistry or diffusion. Ordinary diffusion. They irradiate it with a particular wavelength."

"Or using mass-spectographs in enormous quantities. It is perhaps possible for a mass-spectograph to make one milligramme in one day, say of '235'. They could make quite a cheap mass-spectograph which, in very large quantities, might cost a hundred dollars. You could do it with a hundred thousands mass-spectographs."

"Yes, of course. If you do it like that. They seem to have worked on that scale. 180,000 people were working on it."

"Which is a hundred times more than we had."

"That shows at any rate that the Americans are capable of real cooperation on tremendous scale. That would have been impossible in Germany. Each one said that the other was unimportant."

"How many people were working on V1 and V2?"

"Thousands worked on that"

"We wouldn't have had the moral courage to recommend to the Government in the spring of 1942 that they should employ 120,000 men just for building the thing up."

"I believe the reason we didn't do it was because all the physicists didn't want to do it, on principle. If we had all wanted Germany to win the war, we would have succeeded."

"I don't believe that. But, I am thankful we didn't succeed."

"One can say it might have been a much greater tragedy for the world if Germany had had the uranium bomb. Just imagine, if we had destroyed London with uranium bombs, it would not have ended the war. And when the war did end, it is still doubtful whether it would have been a good thing."

"The point is that the whole structure of the relationship between the scientist and the state of Germany was such although we were not 100% anxious to do it, on the other hand, we were so little trusted by the state, that even if we had wanted to do it, it would not have been easy to get it through."

"Because the official people were only interested in immediate results. They didn't want to work on long-term policy as America did."

"Even if we had got everything that we wanted, it is by no means certain whether we would have got as far as the Americans and the English have now. It is not question that we were very nearly as far as they were, but it is a fact that we were all convinced that the thing could not be completed during this war."

"It is possible that the war will be over tomorrow."

"The following day we will go home."

"If we had worked on an even larger scale, we would have been killed by the Secret Service. Let's be glad that we are still alive. Let us celebrate this evening in that spirit."

8 August 1945
All the guests have been extremely worried about the press reports of the alleged work carried out in Germany on the atomic bomb. As they were so insistent that no such work had been carried out, I suggested to them that they should prepare a memorandum setting out details of the work on which they were engaged, and they should sign it.

As the press reports during the last few days contains partly incorrect statements regarding the alleged work carried out in Germany on the atomic bomb, we would like to set out briefly the development of the work on the uranium problem.

1. The fission of the atomic nucleus in uranium was discovered by Hahn and Strassman in the Kaiser Wilhem Institute for Chemistry in Berlin in December 1938. It was the result of pure scientific research, which had nothing to do with practical uses. It was only after publication that it was discovered almost simultaneously in various countries that it made possible a chain reaction of the atomic nuclei and therefore, for the first time a technical exploitation of nuclear energies.

2. At the beginning of the war, a group of research workers was formed with instructions to investigate the practical application of these energies. Toward the end of 1941, the preliminary scientific work had shown that it would be possible to use nuclear energies for the production of heat, and thereby to drive machinery. On the other hand, it did not appear feasible at the time to produce a bomb with the technical possibilities available in Germany. Therefore, the subsequent work was concentrated on the problem of the engine, for which, apart from uranium, heavy water is necessary.

3. For this purpose, the plant of the Norsk Hydro at Rjukan was enlarged for the production of larger quantities of heavy water. The attacks on this plant, first by the Commando raid, and later by aircraft, stopped this production towards the end of 1943.

4. At the same time, at Freiburg and later at Celle, experiments were made to try and obviate the use of heavy water by the concentration of the rare isotope U 235.

5. With the existing supplies of heavy water, the experiments for the production of energy were continued first in Berlin and later at Haigerloch (Wurtemburg). Towards the end of the war, this work had progressed so far that the publiding of a power producing apparatus would presumably only have taken a short time.

Remarks :

Paragraph 1. The Hahn discovery was checked in many laboratories, particularly in the US, shortly after publication. Various research workers, Meitner and Frisch were probably the first, pointed out the enormous energies which were released by the fission of uranium. On the other hand, Meitner had left Berlin six months before the discovery and was not concerned herself in the discovery.

Paragraph 2. The pure chemical researches of the Kaiser Wilhelm Institute for Chemistry on the elements produced by uranium fission continued without hindrance throughout the war and were published. The preliminary scientific work on the production of energy mentioned in paragraph 2 was on the following lines : theoretical calculations concerning the reactions in mixtures of uranium and heavy water; measuring the capacity of heavy water to absorb neutrons; investigation of the neutrons set free by the fission; investigation of the increase of neutrons in small quantities of uranium and heavy water. With regard to the atomic bomb, the undersigned did not know of any other serious research work on uranium being carried out in Germany.

Paragraph 3. The heavy water production at Rjukan was brought up to 220 litres per month, first by enlarging the existing plant, and then by the addition of catalytic exchange-fumaces which had been developed in Germany. The nitrogen production of the works was only slightly reduced by this. No work on uranium or radium was done at Rjukan.

Paragraph 4. Various methods were used for separating isotopes. The Clusius separating tubes proved unsuitable. The ultra-centrifuge gave a slight concentration of isotope 235. The other methods had produced no certain positive results to the end of the war. No separation of isotopes on a large scale was attempted.

Paragraph 5. Further a power producing apparatus was prepared which was to produce radioactive subtances in large quantities artificially without the use of heavy water but at very low temperatures.

Paragraph 3 and 5. On the whole, the funds made available by the German authorities (at first the Ordnance Department and later the Reichs Research Board) for uranium were extremely small compared to those employed by the Allies. The number of people engaged in the development (scientists and others, at institutes and in industry) hardly ever exceeded a few hundred.

Signed

- Otto Hahn - Walther Gerlach - P. Harteck - K. Wirtz - H. Korsching - M.v. Laue (My signature signifies that I share responsibility for the accuracy of the above statement, but not that I took any part whatever in the above mentioned work) - W. Heisenberg - C.F.C. Weizsacker - E. Bagge - K. Diebner