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Oral History Transcript — Dr. Michael Wilcox Perrin

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Interview with Dr. Michael Wilcox Perrin
By Mark Walker

April 11, 1985

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Michael Wilcox Perrin; April 11, 1985

ABSTRACT: Topics discussed in this interview include: Michael Wilcox Perrin's war work with the British atomic bomb, his management of the Allied intelligence of the Nazi atomic bomb, Werner Heisenberg, Samuel Goudsmit, Carl von Weizsacker, and John Anderson.

Transcript

Walker:

…the part of the story which you personally played a role in.

Perrin:

Yes.

Walker:

— do this scientific intelligence, and also, your interactions with the German scientists after thee were captured.

Perrin:

Yes.

Walker:

And, how can I put this? Your impression of their attitudes and what they thought that they believed and how this change of course and so on, and finally, before I forget, the other thing, is — as soon as you have to go, you must tell me.

Perrin:

Yes, yes.

Walker:

The other thing is, like every historian who is interested in these things of course I’m intrigued by the Farm Hall case.

Perrin:

Yes.

Walker:

And I also know that it’s not very likely that it will all be made public. However, if there is a possibility, I think I have — if it’s possible, I have the proper credentials. I am a student at Princeton. I am an historical student and if you would know the name of the person who I would officially contact —

Perrin:

It’s not, that I feel the same thing about Farm Hall. Because it is all recorded, from the first time when they got together and, they asked to come in to the city where was and here the first news. And then, their reactions, and some of the points had been published. I think mainly because Chadwick, they sent Chadwick a copy of the conversation, the general translation, and the various relevant conversations and reactions and so on, and —

Walker:

He gave it to Groves?

Perrin:

He must have given it to Groves. That’s the only way Groves could have got it. Because still, the Foreign Office is responsible for the main secrecy and so on and so forth, and it’s very much on the grounds that, as I understand it from them, that they say that so long as the Germans in Farm Hall had their arguments and their discussions and their ideas of what it was and so on, that this could be very emotionally embarrassing to our relations, even if they’re dead (for their relations even if they’re dead) and the Foreign Office takes the view that in order to keep reasonable relations with Germany, so to speak, to keep that on the thing, it wouldn't be wise to let the public know the way in which they did talk about each other and how stupid one was and how —

Walker:

Well, I have a, in effect, I know what is likely on the tape. I certainly know there are no scientific secrets to be found there.

Perrin:

No, a lot of scientific nonsense.

Walker:

What is to be found there I’m sure is in the heat — well, well, I know the scientists were they themselves made a distinction, they said, “We’re not pro-Nazi but we are pro-German.” And that allowed them to be very nationalistic and —

Perrin:

— yes, apart from the ones who were of course Nazis.

Walker:

Some were members of the party as well. I imagine that after the war was over, those captured in England, especially as time dragged on, that they said some less than pleasant things about the British, about the Americans, about each other, about —

Perrin:

Oh yes —

Walker:

And especially these things they wouldn’t want a historian 40 years later to publish. The one thing, it’s not that important to me, I wanted to at least make a token effort simply because if they can be obtained, then I should see them, if I’m going to write about this. If they can’t be seen then I will content myself with what has been published.

Perrin:

Yes.

Walker:

And I know that Groves took the most damaging, some of the most (crosstalk)

Perrin:

(crosstalk) (I have?) had a very low opinion of General Groves, and from the — From the forensic(?) side. I had not the ones that — and as I was in Washington, a good deal — but had a meeting out there in Washington and Groves and one or two of the others, who was the scientist he had attached to him (?) I can’t think of names now. A very nice chap. But anyhow, they came down to visit Bellows (?) at that meeting and so I had a chance then, and it gave me a verbal account of where I thought, we thought, they were at that time. And just to put it in general terms, there is no reason to classify any of this thing at all in Germany. They weren’t even beginning. And his reaction was as typical one, that well, you may be right, but I’m not going to believe a word of that until I’ve it all in the bag. He had no conception of the – I’ve talked to people who say Heisenberg and the more Nazi ones, there were few Nazi ones, and they were very much so and of course, nobody realized until after the war that the key lot with the Germans could and would have done the whole thing, and those were the group who were linked with the man at Ardennes, (?) the Russian side of Berlin, and one of that lot certainly saw the possibility of a fast reaction, of a bomb. And the others never did.

Walker:

I’ve got my own opinions of this, and I think, the one problem with people, they automatically assumed that Heisenberg was in charge and that he was aware of every aspect of the program, but as I see it, the program was very fragmented, and the more the war went on, the more it was fragmented, and I have evidence which — that certain German scientists, not the ones in Farm Hall, knew very well that this fast neutron bomb reaction, knew very well all these things. Heisenberg, they weren’t on good terms with Heisenberg, Heisenberg had decided this was the way it was going to go, and his group went for it and so Heisenberg for example was very confused about bombs. About the mechanism of bombs.

Perrin:

Yes.

Walker:

But it’s not fair to say that the Germans didn’t know that a bomb would use fast neutrons. That’s a very simple thing, a very simple process. But of course, after the war Heisenberg emerged as the leader, and there are many other scientists who did, who examined parts of the problem, but they were usually discouraged when they found that Heisenberg ignored them.

Perrin:

Yes.

Walker:

Or that they were in the — for example, half way through ‘42, Speer backed the Kaiser Wilhelm Institute. And he didn’t, he gave them high priority, but all the scientists who weren’t working in the Kaiser Wilhelm Institute didn’t get the priority, and there work was way down.

Perrin:

Well, they had of course through this city (silly?) thing which, I’m sure you’ve got this story, that when, after the outbreak of war, there were two groups.

Walker:

Yes.

Perrin:

The very ineffective — their —

Walker:

That’s Asaw.

Perrin:

Asaw, he had by chance some uranium. He was a great [???] Nazi, and thought he really had got the and Galler, who knew more about this sort of thing than he did, and said, “Now, look, we’re going to have a completely secret thing on this and we’re going to get the bomb and all the rest of it,” and then Galler of course was a complete very advanced Nazi —

Walker:

Do you mean Volta Galler?

Perrin:

No, no, I don’t know the names, but, no, the man who was taken over into Asaw’s setup, and two weeks later, the military boss who happened to be Schumann who wasn’t a physicist at all, he got hold of it, and he pinched the — pinched Galler –

Walker:

Pinched Asaw?

Perrin:

No, Asaw was the boss. There were two bosses.

Walker:

Yes, Asaw and Diebner.

Perrin:

Diebner’s the man, you must check me because I cannot remember names. Diebner was a really violent active Nazi, (?) and Asaw collared him first and then, this does come in early, he was short circuited by Schumann, who was again not a physicist but a musician.

Walker:

Yes, well —

Perrin:

— more or less, and he grabbed Deibner back. And one of the things in Farm Hall which was very noticeable was that all except Diebner — they really sort of ganged up together and all of that, but none of them would touch Diebner. For one thing, they caught him cheating at the game of bridge. And they wouldn’t talk to him. He was completely — now, I don’t know how good he was. I don’t think he was a really good physicist but he was an adequate one.

Walker:

Yes.

Perrin:

But the ones who really mattered were the ones who went over to, who had tremendous lot of skill in —

Walker:

— in getting funded.

Perrin:

In getting funded, had tremendous things and he could have and would have tried to get that four together. And would have provided them, through the postmaster general at the time, and the postmaster general was persuaded to go to Hitler himself, and to say that we thought this is something we can do better than the others. And the same thing happened when they moved Diebner at first, as they did, into the Kaiser Wilhelm Institute, and as soon as, I think this is correct, the director of all the institutes said, “Well, I’m not going to appoint him in place of Debye,” and von Weizacker and one of the others had the bright idea to get Heisenberg as a part time active head, and then Diebner got pushed out of there, or got out. And he couldn’t do anything by himself. As far as I can make out, from anything there, was that he was really only acting as a hold out on both heavy water stock and uranium stocks and allocating it out, either to Schumann’s setup, or to Heisenberg’s setup.

Walker:

I don’t think that’s correct. After he went to [???] he gathered a group of younger scientists and engineers and had his own — he tried his own reactor experiments.

Perrin:

Yes, he did. He did, because he was, the Heisenberg lot had to appeal to him to get allocations of the, both the uranium and the heavy water.

Walker:

Yes, everything that was controlled by the army.

Perrin:

Yes. And he was the person. He was an adequate physicist, but, all the way through the story, the different groups, this is one thing that’s very striking, I think, there were different groups, apart from the Nazis and the non-Nazis, there were different groups that said, “We can do it this way, we want some heavy water, we want some uranium, we want it in flat cubes, we want it in plates, we want it in cubes,” and of course, Heisenberg with who was working with him wanted the metal uranium, and of course, none of them, until they learnt it the hard way, twice, knew that if you get very fine powdered uranium in contact with water, whether it’s heavy water or not, that they will get hotter and hotter and they lost an awful lot by that. The two main experiments that they did at Leipzig, the first one, it started fizzing before — there was a leakage, obviously and they had a fire there. And then they went off with the second report, leaving it running, and when they came back, the thing was a catastrophe again. The thing that strikes me about it is that they had no single organization aiming at the same end point, and the larger group at Ardennes(?) of course were also then captured by the Russians, and, who was that top guy? Beria. He took them. If they had been left, or if they had got a thing going, — because Ardennes did get his postmaster general to go to Hitler and the story is that he said, “Well, I’ve had the Berlin people doing all these wonderful V-1s and V-2s and things like that, and here are you, postmaster general, coming along and telling me that you're going to get a super bomb! Get out!” It was a complete schomozzle from their point of view. They had no real organization. And I think this stands out a mile. It’s due to the fact that, well, Heisenberg is basically entirely a theoretical physicist.

Walker:

He had no conception of what it takes to carry out an experimental project.

Perrin:

Not a bit. Not a bit. I mean, he was thoroughly thinking in advanced mathematics and all the rest of it, and I suspect that in some cases is right in the things he said. Of course, they muddled two meetings. There was to be a fast (?) meeting, a few people — That was Asaw and another chap, going against each other.

Walker:

That’s example of where I don’t, some of the facts are correct but I think the interpretations are wrong. There was to be a double conference in February, 1940. One was a popular lecture series.

Perrin:

Yes.

Walker:

The one at the other was technical papers among [???] the scientists themselves.

Perrin:

Yes.

Walker:

And everyone was invited, Goering, Himmler, Speer, all those people were invited to the popular lectures but none came. And Irving finds that Himmler was sent the wrong invitation. But I really don’t think that they would have come to such a meeting anyway.

Perrin:

No.

Walker:

It was put on by the education ministry, and the audience was full of low level education bureaucrats. To give you an example — to give you another example, in June of ‘42, Speer went out of his way to meet with the scientists, and the reason why was that Speer was recommended to the scientists by two very important people. One was who was head of the Kaiser Wilhelm Society and head of Germany’s largest steel concern, and most important an early supporter of Hitler. He for example had the honor of sitting in the first all-Nazi parliament. And the second was a General, General Fromm. Now, it was after Speer was recommended to this group of scientists, then he had a meeting with them, so I think it’s a little too theatrical to think that the secretary of air (?) caused the project to go under. I think that as soon as Speer had reason to think it was important to meet the scientists, he did.

Perrin:

But didn’t they say, the one who was asked this question by Speer, “How much are you going to want?” and he gave some ludicrously low figure.

Walker:

Yes, that was —

Perrin:

— and so he said, “Well, that doesn’t interest me.”

Walker:

Well, yes and no. Speer decided that an all-out effort did not interest him, but he — that was Heisenberg — he went out of his way to support the work at an experimental level. He made sure that Heisenberg and Hahn, all the Kaiser Wilhelm Institutes, could continue working.

Perrin:

Yes.

Walker:

Also I found some very interesting things in Heisenberg’s papers, which he didn’t brag about after the war. In 1943 Heisenberg was awarded the War Service Decoration First Class, one of the highest awards given in Nazi Germany. He didn’t receive it from Hitler personally, it was sent through the mail, but he received it because he was recommended to Hitler personally by Speer. So Speer was quite content to let these scientists, he made sure that these scientists could continue their work, and as the war got worse, that meant that they retained the priority necessary to — Speer made sure they retained the priority necessary to build a building, he made sure that they received the priority necessary to continue trying to get heavy water from Norway. So it’s yes and no. It’s true that Speer decided, this obviously isn’t going to affect the war, but it’s also, it isn’t true that he was disgusted with them, he thought that they were naive scientists, but it sounds interesting, we should support this politically.

Perrin:

Yes. Yes, I think that is right. The other thing is that — this is Irving again — that Speer said to Heisenberg, “How big is this bomb going to be?” and he said, “About the size of a pineapple,” or something like that.

Walker:

But that doesn’t agree with what he said at Farm Hall. At Farm Hall Heisenberg thought that they would need tons of fuel.

Perrin:

Did he?

Walker:

Yes, that’s one of the things that Groves cites. Let me get back — OK —

Perrin:

— it might be —

Walker:

That’s an example of shoddy historical work. See, I’ve read Irving’s book very carefully, and there are no foot notes, but in the back there’s a list of sources. Now, Irving is an entrepreneur. He collected a great deal of material and he made microfilm copies of it, and he sells them, you can order these things, — they’re very expensive but you can order them, and I had access to microfilm sources that he used for his book, and it’s exactly what he lists in the back, one thing after another. And I was interested in this so called critical mass because it seemed it seemed contradictory. At one point, Heisenberg appears to be saying that he knew he had an estimate similar to what the Americans and British used when they started off with the effort. In other places, Heisenberg seems to use a really crude quick calculation, and came up with a figure that, instead of critical radius, instead of a radius on the order of centimeters it’s on the order of meters, and that worked out to tons of uranium, pure uranium, and so he thought that this, I’m convinced that this estimate about the pineapple, so to speak, is a fabrication. It came from Heisenberg after the war. Irving takes this from what Heisenberg told — that’s the problem with Irving is, some things, some parts of the book he took from public sources, from sources of the time, from a reporting 1943, but other things in the book he takes from an interview he had with Heisenberg, 1966. And you can't tell reading the book where they’re from, and the pineapple story, Heisenberg said, — Heisenberg was very cagey, he said, “I don’t remember it myself.” Heisenberg wrote Goudsmit in 1949, ‘48, and Heisenberg, this is the genesis of the pineapple story, Heisenberg wrote to Goudsmit, “Well, I don’t remember it myself, but I was talking with Ans who was in the Kaiser Wilhelm Society, and he remembers and a secretary remembers that one of the generals asked me how big it would have to be, and I said it would be about a pineapple.” To make a long story short, this rests on the flimsiest [???] of evidence, and also, after the war, you see, it appears clear, well, I know, for example, that Heisenberg spent very little time on the theory of nuclear reactors. He wrote two reports, between 19(?) and 1940, and then nothing else. But these reports became dogma. He suggested that they use layer machines and that’s what they were going to use.

Perrin:

Yes.

Walker:

No one questioned it until the very end, and although there’s no written evidence, from, for example, what R. V. Jones and Charles Frank mentioned they remember from meeting the prisoners of Farm Hall, it turns out from the descriptions, that Heisenberg was very surprised that the Americans had managed to make a bomb because he thought they would need tons of pure uranium-235 or plutonium, and then Heisenberg, the next day Heisenberg gave a seminar, he obviously spent the whole night working out the real problem, and he started off with this crude calculation, he said he did quickly in 1940, which is a very crude, to simplify, it’s a crude calculation you’d expect a physics student to do the first time you give him a problem on the board. And he came up with tons. And later, in the same seminar, then he did it in a more sophisticated manner which came up with estimates similar to what the Americans and the British came to, and he mentioned that he himself, he wasn’t aware that he was being recorded but he gave the clear impression that he’d made a mistake and this was how it worked. You don’t remember the leaves a portion of [???] the tapes out — were you actually there or did you actually listen to the tapes?

Perrin:

Anything that Welch, who was, thought was [???] interesting or relevant or significant, not just ordinary conversation —

Walker:

No, that would have taken a long time.

Perrin:

A long time, yes — he had them, they were translated and radioed and I got a copy. And Chadwick got a copy from the States. The inaccuracies about these things are, another thing, you remember that section in (?)’s book about his interview with Bohr?

Walker:

Yes.

Perrin:

Well, when Bohr came over here, that was one of the things — I said to him, I said, “Did you remember this, what happened there?” He said, “Nothing of the sort, purely imagination.” Irving’s got a sort of variant of the story.

Walker:

Once again he took that from Heisenberg.

Perrin:

Yes.

Walker:

— took out from Heisenberg. I know a great deal about how and Irving wrote their books because I’ve read — because they corresponded with Heisenberg and I’ve read their letters.

Perrin:

Yes.

Walker:

In Munich and Irving was I think, became, it’s interesting, suffice to say how Irving came to the idea of writing the book. He’d already written a book about the destruction of Dresden, and he was working on this book about the rockets, the German rockets, and he came across a remark about using uranium tipped shells. Now, they were used because toward the end of the war, they didn’t have very many heavy metals. They used uranium because it’s heavy, no other purpose, and that shows you something of how important they thought the nuclear fission project was. But they did, toward the end, tip some of the rockets with uranium because it was heavy metal. And Irving wrote to Heisenberg saying, “Are you sure that this doesn’t signify a nuclear missile?” But he corresponded with Heisenberg and I got the impression that Heisenberg saw him I think as a way to “set the record straight” as he saw it, to put his view of the matter, and I think Irving was sort of taken in by the fact that this great man was willing to spend so much time with him and help him so much, and in the end, — a typical example, Irving wrote a draft, sent it to Heisenberg, Heisenberg said, “Well, I don’t agree with these parts.” Irving wrote back, “You’re right, of course you’re right, I’ve taken them out.” That’s about the level of the book. And asked Heisenberg about specific things, two specific things — his visit with Bohr and, well, “the moral standing,” loosely put —

Perrin:

— yes —

Walker:

And Heisenberg wrote him two long letters back, and in this sense, I think took advantage a little bit of Heisenberg, because, one example will suffice, Heisenberg wrote that in a dictatorship, open resistance is futile, thus it appeared to be the only possible resistance was to try work within the system and save what you can. That’s his apology in a nutshell for his behavior. And quotes this in his book. However, to give Heisenberg credit, Heisenberg in his letter immediately followed this with a sentence which said, “Of course I was deeply ashamed by the attempted coup on Hitler in 1944, where friends and acquaintances of mine bravely gave their lives, and I realized how futile my conduct had been.” Didn’t cite that in the book.

Perrin:

No.

Walker:

So in that sense he twisted Heisenberg a little himself. Heisenberg was incredibly obtuse about these matters.

Perrin:

Yes. Yes. I mean, they had a thing — from what we got through from this — of course, more than R. B. Jones, who James rarely had very much to do with the intelligence, I mean, he was absolutely up to his eyes in his flying bombs and things like that and radar things —

Walker:

— you mean he wasn’t much involved with the nuclear.

Perrin:

No. But James is a very funny man. I knew him in a sort of way quite well. He’s obviously absolutely brilliant, but he’s a complete grabber. He wants everything. He obviously, he was in the war at the same time the head of AR intelligence, and that’s where he was doing all his work on the — but he also had a chair in the SIS, MI 6, which was where Welch was, and James’s story is that when they got the first information about the Norwegian heavy water, he said to Welch, “Look, this is something you ought to look into,” because Abrams (?) wasn’t under him, and they were very conscious of it. Welch kept things very close to his chest if he wanted to. He said, “What’s heavy water?” And Jones (and James?) said, “But you ought to know, you're a chemist and you’ve been doing all this sort of thing, you’ve been working in Norway for the whole of, between the two wars, you know, in a Norwegian company, paint company. Of course you must know.” And Welch with a bland smile said, “Never heard of it.” Of course he wasn’t going to tell Jones. They were completely like that with each other. And he got the whole gang going, of course. He’s an interesting man. He’d been in Naval Intelligence in the First War, and when that was over, with a lot of imagination he took a job, he got a chemistry degree, he took a job at this paint works in Norway, and he married a Norwegian girl and he lived there between the wars. And apart from what he did to help the paint company, I wouldn’t know, but he made an absolute network of people all through Scandinavia, on whom he could call. He realized there probably would be something over there. And when it did come to the point, he had contacts there that he’d worked up over this time period which of course Jones hadn’t got. I mean, he had nothing to do with it at all. But he was very secretive about telling anybody. It was all right with me, because I was a sort of animal in alloys and it didn’t seem to matter. Anderson, head of MI6, asked could he have somebody to keep him personally in touch with intelligence. Eric Welch was sent over. He and I got on perfectly well together because he realized that I couldn't possibly scuttle anything that he was going to play with, and I think he wanted more or less a bit of guidance as to what could be done. But Jones, it was a funny thing which I can’t get to the bottom of yet. I’ve tried every single route I can think of. They wanted me — have you seen this series of British intelligence in the war?

Walker:

I think so.

Perrin:

It’s an official history, and it’s done in three volumes, most of which were done in terms of each year, three or four, and they have historians in the Cabinet office, and presumably [???] to write up anything as historians, and they had a vague sort of go in the first volume which of course didn’t go anywhere, it just started on the heavy water raids and things like that. So the final volume has got a part 2 in it in which they decided to tell the full story, forgetting the year by year, of things like the landing in France and one or two other things. I think the flying bombs and things like that. And that they’d like another one on the story, which I’m supposed to be doing. I’ve nearly finished. That’s all under the auspices of the professor of history at Cambridge. He's the official author. After we cleared up everything especially in the area, Welch had got a onetime pad (pass?) and the — he got empty wine bottles and stuck candles in them, and I dictated, and Welch took it down and he converted that one time pad into a long cable, which we had our own for, and the thing had to be sent of course as a onetime pad, nobody else, from Welch and myself to Jones, personal, for, personal, for Anderson, and I know that cable went off, but no one can find it, in any of these. And I’m personally convinced that either Jones tore it up, or he’s got it locked up in some cabinet which he's never going to disclose to anyone.

Walker:

It’s interesting, I wrote to Jones asking if I could come interview him but I never heard anything from him.

Perrin:

You never heard anything?

Walker:

No.

Perrin:

No, he’s — what?

Walker:

Perhaps he’s not all that keen.

Perrin:

Well, I don’t know. He’s written a book and there is a chapter in it on this which is wildly inaccurate. I mean, it’s all imagination.

Walker:

Well, it sounds as if he was a little put off that he never got his share in —

Perrin:

I think, from what I can remember of the Farm Hall conversations and the quotations, it just shows up that they never had one single dive (?) on the thing. They were all really at each other’s throats and didn’t like each other. I imagine that Goudsmit’s publication, in his book, the letter they found from Heisenberg to him, it’s asking couldn’t they please give him a better reputation, on Nazism, is – Heisenberg’s relations knew him as —

Walker:

Yes, Heisenberg’s mother knew Himmler’s mother.

Perrin:

Yes. And he didn’t get much of a on it, reading from that, the letter that —

Walker:

That reminds me of something else I wanted to ask you about. Two things, Samuel Goudsmit and the last, the days in when you were busily arresting the scientists and taking apart the machines and that sort of thing, I mean, Goudsmit wrote his book of course and mostly he wrote his book without reading the scientific papers.

Perrin:

Yes.

Walker:

And. he would have been better to wait, because he was later caught on some of the inaccuracies.

Perrin:

Yes. Goudsmit’s book is way up in the sky somewhere in a general sense, I mean, he doesn’t give facts and dates and exact importance of things. I think, I knew him, and — long ago, in Holland, Utrecht, I think I knew him vaguely them. But he was a very very nice person. No, instead of saying, what he did argue was the debate with the Germans when we had them, and he was much more inclined to ramble off into what he thinks about it himself.

Walker:

How did he interact with the Germans in the war? It must have been very tense, as diagnosed it.

Perrin:

Yes. He took the line, not with the Deibner types, but the other ones, von Weiszacker, Heisenberg, I mean he had a great respect for them.

Walker:

They had been very good friends.

Perrin:

Yes, good friends. I was saying, quite obviously there was, I think somewhere quite early on in this story, is that there was no need for us to come here in the mission at all — I mean, they haven’t done anything and they aren’t going to be able to do anything. And when there was a question of stopping the French at the Left Bank of the Necker, and putting the US Army down in — I think that was it — and they were delayed a bit, and the French knew that was a few miles ahead, fast with him, and got a new order from Eisenhower that stopped them getting across the Necker, and then, was very wily, (?) and they said, “Well, we’ve got to get in” and said, “Well, let’s persuade the General to do an air drop into the area that we want,” and Sam Goudsmit in his book says he wasn't about to have even risk (crosstalk) I mean, he was quite convinced all the time you see that there was nothing there.

Walker:

In retrospect, it’s quite clear to me as well that it shows you what happens when military men are making decisions about scientific matters.

Perrin:

Yes. They really didn’t know, basically, that there couldn’t be anything possible there.

Walker:

Well, I’ll make a distinction between research on the uranium question, and the possibility of a successful drive to build a bomb. Now, it must have been clear that the Germans could not be making what the Americans made at Los Alamos.

Perrin:

Yes.

Walker:

They could well be doing experiments on isotope separation and nuclear reactors, but it was a plaything compared to the American — and that, just by counting the number of scientists involved, the fact that the Germans were publishing some of the publications about these things —

Perrin:

— yes —

Walker:

The fact that our intelligence knew roughly what — which German firms were doing what — it must have been clear to a rational person who wanted to consider it, but it was much more cowboyish too.

Perrin:

I mean, men in their senses, whatever country they were, when they allowed Hahn to go and give lectures in Sweden, and line up with Meitner, tell her all about it, what he was doing, I mean, if they really had thought that they were going to have a military weapon, he would have been — he would have found that impossible.

Walker:

It’s clear from my research that early on the Germans worked out that these things are possible, nuclear engineer control systems, but once again, it’s a very simple problem. But during the first part of the war, during the Blitzkrieg days, the Germans didn't need any wonder, the Germans thought they were going to win.

Perrin:

Yes.

Walker:

And by the time, after the Blitzkrieg stopped in Russia, and especially after Stalingrad…

Perrin:

Yes.. (off tape)

Walker:

They didn’t think it was feasible during the war.

Perrin:

Oh no.

Walker:

And so that explains their behavior, really. They continued working on it because it was interesting, because it was so-called war work, which meant that they didn’t have to be drafted into the army, things like that. They were very concerned about that. And they just wrote reports and that's why they were so utterly confused and bewildered when they heard that the Americans (had the bomb) because at the very end, they were certain that, “We’ve only come so far, that’s proof that the Americans are behind us.”

Perrin:

There’s one of the extracts which I think has been produced from Farm Hall, was, one of them, and I can’t remember which one it was now, it might have been Diebner, said, “You know why we’re being kept here.” (crosstalk) “They want to see what we’ve done and repeat all the experiments and see if it's right.”

Walker:

That was Vahga.

Perrin:

Was it?

Walker:

He was the only one who was friendly with Diebner. He became very good friends with Diebner. I interviewed him. He said that he was forced to share a room with Diebner at Farm Hall and they gradually became friends.

Perrin:

Where did you find this (?) I didn’t know that.

Walker:

Oh, I talked to him.

Perrin:

Oh, you talked to him. Because he has written quite a (crosstalk)… diary he kept…

Walker:

He published parts of it.

Perrin:

Published parts of it.

Walker:

Yes. Some parts he didn’t publish are more interesting.

Perrin:

Yes.

Walker:

But he indeed, part of this diary was in a book which he and Diebner published.

Perrin:

Yes.

Walker:

FROM URANIUM FISSION TO CALDER HALL?

Perrin:

That’s the book yes.

Walker:

From about ‘55 he and Diebner were very good friends, although he was still friendly with Heisenberg. He was a funny, sort of in between —

Perrin:

Yes. I know some of the top brass objected violently to Vahga when, being brought in with the lot of them because they thought he was much too junior.

Walker:

Yes, but he had an in with the army.

Perrin:

Yes.

Walker:

Because in 1938 Vahga had written a paper on the disintegration of deuterium, smashing deuterium, one at a time, and he gave a talk about it, and after the talk an old physicist took him aside and said, “You should take up something practical. This disintegration of nuclei will never lead to anything.” But also he had just taken an assistant’s position with Heisenberg, and that’s the main reason he joined the Nazi party, in order to grease his path upward, so to speak, and after this lecture with the army Herr, the army weapons development center, had set up branches of chemistry, physics, biology, and the head of the physics branch was Diebner, and after Vahga gave this talk, people from the science branch were there, and they came up to him and said that they obviously were impressed, “Would you like to join us, would you like a job?” And Vahga said, “I’ve just gotten an assistant’s position with Heisenberg, I’ll stay there.” But a year later after Hahn’s discovery, when they decided to set up the project, they had their expert, Vahga, who’d given the talk on the disintegration of nuclei, so they brought in him right away. See, the people in the army had no idea what these things meant, but they had heard some physicist give a talk about these things. Vahga since he was in the Nazi party was easier to bring in than others, so they brought him in. And he’s the one that brought Heisenberg and von Weizsacker and the other people in, because Vahga was asked to help set up the project, the project, “Who do you think should be in?” and he said, “Well, of course you must invite Heisenberg for the theory,” and then Heisenberg was in.

Perrin:

Yes.

Walker:

It’s about five after —

Perrin:

— it’s all right, I can…

Walker:

About taking in, how did these scientists react when you came in? I imagine they were simultaneously antagonistic and relieved.

Perrin:

Relieved. Of course they were in different places. I mean, Heisenberg had gone, up to his place up in the mountains. Hahn was in a different town, Vahga was in and so was von Weizsacker, they were both there, but Vahga was in a different building, trying to make his —

Walker:

(crosstalk) — separating —

Perrin:

— yes, about the sixth time. I felt sorry for him because just as he got it there he had this man — some way — but no, they were completely, Weizsacker was cleverest in a way.

Walker:

He still is.

Perrin:

And still is, he started to — he has makeup in him because, I mean, he kept back the stocks of uranium and heavy water had been hidden, and the papers (where the stocks of uranium and heavy water had been hidden) and the papers, in a can under the —

Walker:

— yes —

Perrin:

It must have been Sam Goudsmit who finally got him to say where they were. That’s the other contradiction (?) angle from Jones’ point of view, they had occasional messages from Switzerland, saying that they reckoned the Germans were going to have uranium bombs, and all the rest of it, and in particular that the fission products of the reactor would be dropped at, could be dropped at say in northern France, and would make landings impossible. And Groves hitched onto that, which is a completely bogus thing, I mean, a person didn’t know (?) obviously — twisted Eisenhower’s arm, by, first of all, he got the theorists to work out the fission products of one of the big, they had three big Hanford piles, three Hanford piles, one of them, and this came of course to some fantastic number, mega curies, and he warned Eisenhower that it might be dangerous to (?) make these landings because all this could be dropped by the Germans, and we wouldn’t have to get shot, but it was grossly unfair because I mean, it was a pure guess on anybody’s part, particularly Grove’s part. I don’t think he had a clue what —

Walker:

— fission products meant.

Perrin:

— fission products out of the major pile, you see. Not a bomb at all. How you carry that over, how you get anybody to fly the plane, if you'll sit within a few meters of it — or anything. But we scotched that one quietly, because I got it checked over here and found it was absolute nonsense. I think the first that — effect was that they were letting out from a small sized nuclear reactor which was just working. I mean, it’s absolutely ludicrous, and I got that across to John Anderson, and he said, “Well, what do I do with this?” I said, “Well, the great thing is, if the Americans completely go to think this can be done on a major scale, its absolute nonsense.” He’s a wily old man, John Anderson. He looked it over carefully and said, “Well, you know, Eisenhower has never discussed this or talked of this to our British chiefs of staff. I’ll write a note to the secretary of the British chiefs of staff to say that there are stories of this sort of thing happening, but we’re quite certain that nobody’s going to drop small sized working active (crosstalk) products of a huge —” He said, (We said?) “Well, we’ve never heard that from Eisenhower.” So Anderson said, “OK, then you haven’t heard it from anybody. Forget it.” We did go through the motions of getting the national physics labs to make a few detectors and send some chaps, when Liverpool was being bombed, we tested the crater and there was nothing there at all. But that was Groves’ behavior, you know, which, he wanted to get more power to himself by getting Eisenhower behind him, then the — At any rate, I’m glad you’ve shaken up my thinking — what did I say (?) which part of the whole story, I mean, from the beginning, the end, the middle and all the rest of it, and it’s the intelligence side really that we can talk about. (crosstalk) What?

Walker:

You want to use your sources. The intelligence side is what you can tell me the most about.

Perrin:

Yes, I think that’s probably true. That is probably true. Because. Because is dead now and you won’t get — I’d be very cautious, if you do get anything out of R. V. Jones, be very careful to cross-check it.

Walker:

What I’m doing actually is, tomorrow I’m going to visit Charles Frank.

Perrin:

He’s much better. Much better. He was at Oxford with me. I knew him. I don’t think you’ll get much from him. You might.

Walker:

We’ll see.

Perrin:

You’ll get more than you would from R. V. Jones. At least you won’t need the same amount of salt to take with it.

Walker:

As a specific, Goudsmit’s book has been republished.

Perrin:

Yes.

Walker:

Goudsmit’s book, it’s been republished, yes, and Jones has written the foreword for it.

Perrin:

Really?

Walker:

Yes. If you’re curious I can write you down, at the publisher, and you might get —

Perrin:

Do, I’d love to see that. Ask Frank if he’s —

Walker:

Ah, this comes the story. In it, Jones, the only thing that interested me was Jones’ recollection of Heisenberg’s crude calculation from the Farm Hall transcripts. And not in Jones’s book but in this foreword, he quotes a letter from Frank to Jones. Jones had obviously asked Frank about this and Frank said, “Yes, I remember the same thing. This is how I remember it.” It’s all in the book, set in type, and I wrote to Jones and asked if I could speak to him. I also wrote to Frank, and I specifically said, “I’d also like specifically to discuss with you the matter that you brought up in your letter to R. V. Jones.” He said — published in this list of and he said, “Well, you’re welcome to come, but I don’t know which letter Jones published in the (?).” He had no idea that it had been published. So I —

Perrin:

Well, I think you’ll find, he’s very nice. I mean, he occasionally, — no, I think, at one stage, Jones said — well, I better deal with Jones — then he said, “Well, I don't think I will; perhaps, because you know him, you can do him,” and came along, but Jones wasn't really very active — in the active community. (?) How long are you going to take before your thesis comes out?

Walker:

Well, the next six months, I’m going to write an article, try to write an article which will be just the German nuclear reactor research, just doing the war, and I hope to have that published as sort of a preview of my thesis. And the thesis, well, it will be done when my funding runs out, and it will either be done in June of ‘86 or June of ‘87, and of course you know this academic game, then I will try to get a temporary job and then I will try to make it into a book while I have the job. As soon as I get anything published, I’ll send you a copy.

Perrin:

I’d like that, because I was going to say, with any luck, I can’t believe it will take as much as a year more before you’ve (they’ve?) done it, Volume 3 is the official history, and Part 2 should be out, but I won’t offer to send you a copy of it. (crosstalk)

Walker:

No, I can find it.

Perrin:

I can do something else. They can charge, oh, anything from 30 to 40 pounds per volume. It’s that sort of nonsense. But — I can get a copy of my article.

Walker:

That would be very good. Have you had access to previously classified material when you were writing this?

Perrin:

Yes. Yes. Otherwise it wouldn’t be much.

Walker:

Well, there wouldn’t be much use in doing it again.

Perrin:

Yes.

Walker:

If you’re curious here is, I’m sure that — I’m sure if you know someone in the libraries they can find you a copy.

Perrin:

(crosstalk) Tomas?

Walker:

Tomas. Yes, it’s a funny company which has been reprinting older books in the history of science.

Perrin:

Pasch (?) told me that he was getting to do another one.

Walker:

Another book?

Perrin:

Yes. He was going to do it. I don’t — he came over. I like Pasch. I know he’s pretty wild. His one and only book isn’t accurate, largely on lots of things.

Walker:

THE MISSION.

Perrin:

Yes. It isn’t at all accurate. I mean, he’s got dates wrong and everything. But he said, he was over here, and I had a talk with him. I pointed out that some of the things he put in his book weren’t quite right. His dates and things. And he said, “Well, I think I’m going to write another book.” I think he was going to have it, the whole of his career, and put in —

Walker:

His memoirs.

Perrin:

Memoirs, yes. He didn’t know of course in the slightest what he was [???] going to deal with.

Walker:

No. But it didn’t bother him.

Perrin:

Not a bit, no, as long as he could get somebody to surrender to him, that’s all right.

Walker:

It’s about time, I think — is there anything else you want to ask me? I always ask that in my interviews. I often get some very interesting questions.

Perrin:

Well, no, except that I would very much like to see it as it goes along, and how you get into it, because some of the things you’ve been saying to me now are not exactly as they’d appeared to me, these relationships.

Walker:

The more I do with this, the more in a sense reasonable and less spectacular the whole thing becomes. It’s not a question that the project was unified and then broke up. It was always split up. And you have to make a distinction between what Heisenberg’s group did and what German scientists working on this problem did.

Perrin:

Yes.

Walker:

You have to make a distinction between what Heisenberg thought and believed, what he kept secret, what all the scientists knew and believed, and kept secret. Because some things Heisenberg thought are utter nonsense. I mean, that’s clear.

Perrin:

Yes.

Walker:

But it’s not fair to say that German scientists all believed this nonsense. Some did work that was very comparable to the American work, in theory. They never actually made anything. They never actually made any plutonium or separated any. But often these scientists became very resigned and fatalistic about it, because Heisenberg was only — Heisenberg always wanted to keep things in his small circle, among his confidantes from — And as the war went on, after Heisenberg moved to Berlin, then he became much more powerful, and after that, and you see the personal backing of Speer, and after that, it was, the scientists who weren’t in Heisenberg’s inner circle, they —

Perrin:

It was always — when he went to Berlin, he also had his roots down in Leipzig, didn’t he?

Walker:

No, (crosstalk) — it changes. You have to look at different periods in the war. From 1939, 1940 to the middle of ‘42, Heisenberg was professor at Leipzig.

Perrin:

Yes.

Walker:

An assistant of his, Durpal (?), actually carried out the experiments. Heisenberg didn’t. He couldn’t have done the experiments. And he came to Berlin occasionally as the advisor. But in the summer of ‘42, he received two calls. He was called to be full professor of theoretical physics at Berlin, and he became the official director at the Kaiser Wilhelm Institute and then Diebner had to leave, that was in ‘42. And then, that also coincides with the fact that, when the Leipzig reactor blew up —

Perrin:

— yes —

Walker:

And then there were no more experiments in Leipzig, and then all the experiments were in Berlin.

Perrin:

Yes.

Walker:

So in a sense these experiments, Heisenberg’s experiments followed him there. When Heisenberg was in two places, there were —

Perrin:

— (crosstalk) and they didn’t use his [???] powder, did they?

Walker:

The first ones they did. They used powder and paraffin. Paraffin was the moderator. The first experiments in Berlin, Dalan(?) were horizontal layers, first, uranium oxide and paraffin, then metal uranium powder and paraffin, and then, Derpal had shown, Durpal himself adds very laconically, “Perhaps it would be better if we used metal uranium.” Then the next experiments were metal uranium plates and paraffin, because they always had a shortage of heavy water.

Perrin:

Yes.

Walker:

And then finally, it wasn’t till 1944 that the Berlin Dalan experiments used heavy water. Then they used metal uranium plates in heavy water. Then finally in the end they switched to cubes in heavy water.

Perrin:

Yes, and that was the last, which they took down and finally put it together in, yes, and they just didn't have enough, because Diebner had gone off somewhere else, with his stuff.

Walker:

That’s another thing, Irving is too theatrical, I think — even if they had managed to achieve a critical chain reaction, say six months earlier, than all they could have done was play with critical reactor machines. They couldn't have done anything else. So it’s not, it’s too theatrical, “they came so close.” They almost made a critical reactor but that’s all they would have (crosstalk)

Perrin:

Heavens, I know, and then they'd have had new problems, to get something out of it. Yes, actually. (They’d have begun new problems?) Anyway, I’m sorry that I have to go.

Walker:

It doesn't matter. I’m pleased that you could find time for me. I scheduled this…