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In footnotes or endnotes please cite AIP interviews like this:
Interview of Betty Schwartz by Aage Petersen and Paul
Forman on 1963 May 17, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/4866
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This interview was conducted as part of the Archives for the History of Quantum Physics project, which includes tapes and transcripts of oral history interviews conducted with ca. 100 atomic and quantum physicists. Subjects discuss their family backgrounds, how they became interested in physics, their educations, people who influenced them, their careers including social influences on the conditions of research, and the state of atomic, nuclear, and quantum physics during the period in which they worked. Discussions of scientific matters relate to work that was done between approximately 1900 and 1930, with an emphasis on the discovery and interpretations of quantum mechanics in the 1920s. Also prominently mentioned are: Mogens Andersen, Aage Berleme, Harald Bohr, Niels Henrik David Bohr, Hendrik Brugt Gerhard Casimir, Hans Marius Hansen, Werner Heisenberg, Oskar Benjamin Klein, Hendrik Anthony Kramers, Mrs. Kramers, Mrs. Maar, Yoshio Nishina, Olsen, Adalbert Wojciech Rubinowicz, Ernest Rutherford, Toshio Takamine; Committee for the National Museum (Copenhagen), and Polyteknisk Laerenstalt (Copenhagen).
Well, this is a copy of the contents of the proceedings of the Institute which I made.
Oh yes, of Professor Bohr’s works.
And others. I thought maybe later we could talk about any of those papers that you remember and also about the visitors.
Yes, I have also a book here of guests of the Institute. It lists from the very beginning.
Yes, that we would very much like to copy.
It was begun in ‘27; here I have written what I could remember afterwards of the years before 1927.
We wanted to ask you about the beginning. We would like to know when you came to Professor Bohr and what the state of the Institute was then, and perhaps a little bit about what preparation you had for your job and how you were hired by him and so on. Usually if people talk about things in fairly personal terms, that is, as they happened to themselves — how the history impinged upon them — then one gets very good and concrete reminiscences.
I can tell you when I came to Professor Bohr, I went out to his home in Hellerup. I had heard that he wanted a secretary and I prepared the whole way what I was able to do. I took shorthand and knew a little English, and such things, but when I came there, he didn’t ask for anything except whether I had been interested in science. And I said, “No, I do not know what it is,” and then I was engaged.
How had you heard that he wanted a secretary?
My teacher in shorthand writing had been in connection with Professor Bohr’s aunt, Hanne Adler, and she had asked whether she had anyone she could recommend for that position. My teacher telephoned to me about it, and I said, “No, I am very satisfied where I am.” But they asked me to try it.
Where were you?
In Hannibal Sander, the farveri.
And what were you doing there?
Office work, correspondence and a little bookkeeping and such things.
So what made you then decide to go out there?
I went because there was no use for my English there, and only very little for shorthand, and it was a very long day there and a very long way. This was better — shorter office time, and a shorter way to go.
Did you have an appointment then with Bohr that day?
Yes. I think he had made an appointment with me, but I was not quite sure. But on the 2nd of January I came to the Polyteknisk Laerenstalt. I was appointed from that date, but there was nobody at all; it was quite empty — the whole Laerenstalt, and I went home again. After a week I went up again, and there was nobody there. Then I went out to Hellerup and found a young lady at Professor Bohr’s house. She said, “Oh, yes I know that Professor Bohr had engaged a secretary, but now he had gone to Norway, and he has thrown your address away.” It was a very curious way in which I was situated here.
And this was 1919?
Yes, the first time it was 1919. It was the 2nd of January, ‘20 I went up there, and I went home again. And I got a letter from Professor Bohr when he got home from Norway saying that I had to come to the Polyteknisk Laerenstalt where we had a very, very small room. And there was Professor Bohr and Kramers and I sitting in one room like this table.
Was Oskar Klein also there then?
He came shortly after; in the beginning of this year Klein came, and Rosseland and Hevesy and Rubinowicz. They were the four first scientists who came. And they were placed in the library beside.
What did you do then, the three of you in that little room?
First I had all of Professor Bohr’s reprints to make a catalogue of. When he was not there, I did that; otherwise he wrote letters and such things, and prepared the beginning of the Institute here. I did the bookkeeping in just a very little book; we had not much money at that time.
Which things had Kramers done that you did now?
He helped Professor Bohr with his scientific work. He dictated also to him and to me, sometimes in the evenings too — very often.
You mean there were all three of you in the room and Bohr dictated letters to you while Kramers was sitting doing physics?
Yes. I was not there every day, because when he should work with Kramers, I could go home, and Kramers went away when we worked. There was not enough space for all of us to be there.
How many letters did you write a day?
Oh, I don’t remember. It was applications for grants to the Institute and such things mostly.
They were still working on raising the money for the Institute then?
Was the committee —
No, from the Danish Government, the ministry.
No, the committee of which Professor Faber was the chairman.
Oh yes. Now it was in the very first beginning, before the Institute here was erected. But it was finished in ‘21, so when I came here it was being built. It wasn’t finished, but it was in process.
I think you once told me that the first time you came out to Hellerup to talk to Bohr, he had hardly seen you and hired you when he began to tell you about the building plans of the Institute.
Yes. I had expected he would ask me about many things — what I could do, but he didn’t. He took all these drafts of the Institute and showed me how it should be — there should his office be, and there should my office be, and such things. It was mostly that he spoke about the first time that we spoke together.
And how long was it then until you did get to the Institute, until you moved into the Institute?
It was in the beginning of ‘21, I think, in January or February ‘21 that we began to come out here.
A full year after you began to work for him?
Had Kramers his doctor’s degree when you came?
Yes, he had.
How much did Bohr tell you about his own suggestions in these drawings. Did he tell you how much he himself had done?
No, I don’t remember.
When did you start working in the morning?
Would he be there?
Yes. Not every day, of course. Yes, he often came at 9:00 o’clock.
How did he get there?
On bicycle from Hellerup.
Then how would the work day go? What would you do first, what would you do next; what would you do before lunch?
Oh, it was not the same thing every day, because there was not so much to do the first year, you see. He had no Institute. But sometimes when Professor Bohr was away I prepared the reprints. I remember Rubinowicz helped with that work when he was here. When there was nothing for me to do then I could go, and walk and go home.
When did Bohr start dictating scientific things to you, right from the beginning?
Yes. In 1919 I was there a few times in Hellerup where he dictated something to me — scientific things.
He then explained to you about the field?
He tried to, yes, but I think he saw really that I didn’t understand anything of it. It’s impossible when one has not studied it.
But you learned the words!
Yes, I learned the words, yes, of course.
Did you do letters, say the first thing in the morning, when you worked together?
Yes, it was different. Sometimes Professor Bohr had to speak with somebody else, and I just sat by myself and wrote that catalogue and such things.
And then you had lunch?
Then I went home for lunch. Sometimes Professor Bohr brought his lunch with him, and took it on his desk.
Were there any Danes there besides Bohr?
No; I saw at that time Professor H. M. Hansen, he was there, and Jacobsen, nobody else.
Jacobsen was just beginning then?
No, I think he had his examination about that time. He was Cand. Mag. I think.
Did Bohr have much contact with H. N. Hansen and Jacobsen?
Much with H. M. Hansen, yes. He gave Bohr much advice about the Institute building and such things — the practical things.
And then you began to get an impression of the guests who came there. You saw Kramers from the beginning. He spoke Danish then already and had for a long time?
Yes, yes. A very funny Danish, but he spoke Danish.
Did you also take letters for him?
Yes, and I wrote a book which he and Helge Holst wrote — I have typewritten this book for them, but it was here in the building here; it was not the first years.
You typewrote all the papers that were done?
Yes, there was only me working.
Do you remember the architect, Mr. Borch?
Yes. Mr. Borch, and his assistant was architect (Munk).
I just saw Borch’s name on the drawings. How did he and Bohr get along?
Very well. They got along fine, but we saw most of his assistant, architect (Munk). He came every day and looked after everything.
Bohr also looked after everything, didn’t he?
Did he draw all the details, I mean for instance, this auditorium — the big auditorium?
I do not know, because when I came they had begun to build the Institute.
But he didn’t tell you whether for instance the system of the blackboards was his own idea?
But it must have been much later that this part of the building was constructed.
Yes, it was much later; there was only the one building, the middle building here. Here was a kindergarten — a community kindergarten.
Oh, here? Whatever happened to that then?
It was torn down. In 1926 this building was built.
Was this the Rockefeller money that you had then?
The first time — I do not remember whether it was Rockefeller money or not. I don’t think it was — no, it was a little later that they came in.
Do you remember the selecting of the first staff of the Institute? There was to be Professor Bohr, and there was to be an Associate Professor, and two assistants and then you; and then a mechanic.
Yes, (Mechanician) Olsen. Yes, that was the first staff.
Do you remember who was who then?
Yes, I think one of the first assistants was Kramers, and there was Sven Werner. Yes, he came a little later; he was one of the first assistants.
Was he already hired as an assistant while you were still at the Technical High School?
No, no. In one of the first years James Franck was also here for a time.
Well, what was Hevesy’s position? Was he made associate professor?
Yes, I think we must have made him an associate professor. He was professor himself, but he was here until, I think, ‘26 or ‘27; then he went to Freiburg. He was professor there.
Can you remember particular incidents when Klein and Rosseland were here? Do you remember the paper which they wrote together, particularly? Do you remember in ‘20 they wrote a paper?
Professor Bohr had time then to go to the theater and so on?
Yes, and to the Bio, [motion picture theater]
That was in the first year or two.
Only the first years, yea. And there was also during the first years, Coster from Holland. He wrote that work about hafnium together with Hevesy.
That was very exciting.
Yes, it was an exciting time.
But that was already after Professor Bohr had his Nobel Prize?
Yes, I think it was in ‘22.
It was just around that time.
Can you picture, say, the fall and early winter of 1922, when Bohr was working with Coster on the periodic system? Can you remember their working together?
Oh, not so much. They may have done so, but I do not remember.
Had you expected that Bohr would get the Nobel Prize?
I don’t know, I don’t really know.
That must have been quite a time then at the Institute.
How did he react to it himself?
I do not remember that very much. One thing I remember — that so many people were coming here to the doors asking for money, because they had read of it in the newspapers. It was my job to show them out. Many people came and many people wrote and asked for money.
Do you remember what Bohr did with the money?
Yes. He had very much use for it; he had children and such things and he used it in his ordinary life I think. But we were afraid he would have given the whole thing to all these people, if we had not said no. He never said no.
Then you had to keep him from seeing them?
Yes. And Mrs. Bohr too.
Do you remember he had to write a speech to give when he accepted the prize?
Yes, yes. No, I don’t remember. Although I must have written it for him.
You often worked with him in the evening too?
Yes, very often. More than I liked.
How often was it — do you remember? Was it many times a week?
He did not work so much then with Kramers in the evenings?
Yes, also, but then Kramers was married, and he could not every night go away from his wife.
Do you remember when Kramers got married?
I think it was the first year. I think it was in ‘20, or ‘2l. She was a Danish lady.
Did many young physicists marry Danish ladies?
Yes. Klein also; Hevesy.
They were always very attractive to physicists.
They must have been. Weisskopf, Mercier, many of them.
What kinds of women do you think appealed to these young men?
They were very different, these ladies. Mrs. Kramers was a singer; he was playing cello and she was singing.
And did they do that together?
Yes. That is in private company.
Did all these guests stick together very much? Did they live at the same place usually, in the same pension?
No. Kramers and his wife had a flat.
Do you remember a Fru Maar?
Yes. Klein lived there. And I think he met Mrs. Klein there. Yes, I remember her very well.
Heisenberg said that Fru Maar had taught him both Danish and English.
Oh, yes it may be.
Do you remember him as a young man? He must have been very young when he was here.
Very young, yes. Such high hair, yes I remember him very well.
He lived here at the Institute?
Yes, in that old building there were two small rooms where he lived. Felix Bloch has also lived there, and Rosenfeld and his wife, and Ehrenfest, and Lise Meitner was there.
Do you remember when Ehrenfest was there?
Yes, yes. I do not remember when it was, but we can find it in the guest book. Yes, yes, I remember him very well.
They were all very different personalities.
Do you remember Aage Berleme?
He came here to this building the first day we were here, Professor Bohr and Kramers and I. And he came with a bottle of wine and some chocolate and a piece of bread and salt which Professor Bohr should eat. He should eat the salt and the bread because it was good luck to do so the first time in a new house. I remember him very well.
Berleme was one of the people on the committee that helped organize the Institute.
Yes, yes. I think he was chairman of that committee. He collected the money and gave a great deal of it himself, I think.
He was a school friend?
He was a school friend of Professor Bohr.
I notice that when Professor Bohr went to America in 1923 — do you remember that?
That was his first visit to America.
Was it? I don’t remember so much of it.
And somehow I heard that Aage Berleme was then your boss, while Bohr was gone.
No, no, no, no. Never, never. He was a businessman, he had nothing to do here. No, he wasn’t. No, I think it must have been Professor Harald Bohr, Professor Bohr’s brother, and H. M. Hansen who took care of the Institute while Professor Bohr was away.
Do you remember the first mechanic? There were two mechanics, there was one that came before you —
Yes, but I have never seen him. There was a man before, but I have never seen him. But the next one who was here for 30 years; he came a few months after me, and there was a little house out here on the ground and there he had his first workshop. Professor Bohr went out there every day and I looked at the things.
Do you know how he was hired?
After an advertisement, I think.
I saw in a letter that he had been sent then to Leiden, to Crommelin, to train him in glass blowing.
In glass blowing, yes, I remember that.
Did he bring things back with him?
No. But sometimes he had to blow glasses here.
Was he somehow in charge of the laboratories when they were once set up?
Yes. He was head of the workshop, yes.
That’s a very powerful position.
Yes. Not at the beginning because he was alone with a pupil, but then it grew. Now there are 8 or 9 people out there in the workshop.
Did Bohr ever work there himself?
Oh, I don’t think so.
He had no time?
He had no time.
He did not go out there in the evenings to do things with his children?
I don’t think so much. But the eldest boys went to Olsen and learned some mechanics — Christian at least, and Professor Chiewitz, too, went to the workshop and learned something from Olsen. It was Professor Bohr’s eldest son who died, you know.
Yes, in the boating accident. Did they spend a lot of time with their boat?
Yes, every summer. It was Professor Bjerrum’s boat, and they sailed every summer.
For how long?
For many years, but not after that time, never.
Was it for some weeks every time?
Yes, I think for two or three weeks.
Oskar Klein spoke of the months before Bohr went to the Como conference in the fall of 1927. Do you remember that at all? He recalled that he had been working with Bohr on a paper that he was to deliver there, and then it was to be sent off as a letter to Nature and they were working and working and they weren’t getting it done. They were rewriting and rewriting and working the whole summer, and then at the very end Bohr was supposed to leave at midnight on the train. And that very evening everybody, you and he and Bohr, were trying to get ready the final copy to send off to Nature.
That was always so when Professor Bohr should go away, then he worked the whole night and made the last things at the railway station on a bench.
Evidently Harald Bohr was there that evening, too, and Professor Bohr signed the letter to Nature, “Niels Bohr,” when he should have written “N. Bohr.” That disturbed him quite a bit.
So? I don’t remember it.
Do you remember when he stopped writing his name himself in his books, and had a stamp made to stamp it in?
He had a stamp, though it has never been used. He had made such a stamp because — now I remember when it was. I think it was about that time when the National Museum was built. There was a Committee and Professor Bohr was on it, and he had to write his name so many times, many hundred, then he had a stamp made. But we were not allowed to use it — it should be handwritten.
How much time did this Committee for the National Museum take up?
I do not remember.
Did he have to go to many meetings?
He had to go to some meetings — sometimes they came out here to speak to him, Knud Rasmussen and Hoffding, Vilhelm Thomsen and H. N. Andersen. It was the five greatest men in Denmark at that time.
How did Bohr happen to be such an active member of that board?
I think they asked him.
And then Knud Rasmussen went away?
Yes; he died about that time — a little later.
At what time was this?
Around ‘24 or ‘25.
And this was the founding of the National Museum?
Yes; there was a National Museum, but a very old one. There was a new one built.
Did Bohr take part in other such projects?
Yes, I think he did.
How do you think he decided which things to involve himself in and which things not to involve himself in?
I think he was interested in that about the National Museum. Later on his brother-in-law was director of it, Poul Norlund.
Now when you look back on all these years, do you then have some feeling of differences — for instance, you know in physics this time was a time of great change. And when you started working, then it was a time when one had approached this quantum theory, but still very much was to be learned. But then in a short period there around 1924, ‘25, ‘26, ‘27, things changed considerably. Could you feel that, too?
Yes, of course, there came so many people in these years.
Yes, but could you also feel it in Bohr? Could you feel as if a crisis had now been overcome?
No, no. He was always busy; he could never come over it, so then there was something else.
Although he was busy all the time, there must still be years where he was more engaged in things.
Yes, I think these hafnium years were very busy years.
And then again about ‘26, ‘27, wouldn’t there also be —
Yes. And also later, when Frisch and Meitner and all these things were going on.
Yes, and also the time with Rosenfeld, in the beginning of the 30’s. When Einstein was here —
He was not here. I have never seen him. I think he has been in Copenhagen.
Yes. He was in Copenhagen in ‘27, I think.
I have never seen him. I don’t think he was in the Institute; wasn’t he in the Observatory with Stromgren? No, I have never seen him.
But Bohr saw him?
Yes, I think. But he has not been here in the day time at least.
In ‘24 and ‘25 and ‘26, when Heisenberg was here a good deal and worked a good deal both with Kramers and with Bohr, can you remember how they worked together. I mean, in some way Heisenberg is a — although he looks like a little boy — very strong person.
I don’t think they worked so well together, because he was independent himself; he worked on his own things. He was not so much help for Bohr’s work. Kramers was much more, I think.
But when it came to having something published, in some way Professor Bohr had to agree. Then they must have had some difficulty.
Yes, maybe; I do not know.
In what way did Professor Bohr agree to the things which were published from the Institute?
He sometimes read it through, and sometimes came with some better ideas and suggested alterations.
And then you typed it up?
Yes. Many, many times.
Then how did he decide to what journal to send it?
When he saw now it was finished, and now it could be sent, Professor Bohr said, “I must just take it home and sleep, and then we’ll send it tomorrow morning.” The next morning we wrote it once more.
Was it mostly in English?
In the beginning there was also some German, but later all English…
When did he give these lectures when he first went to Gottingen? Was that in ‘21?
It was the summer of ‘22.
That was, I think, the first time he gave a series of lectures on his work. Do you have any recollections?
That must have been a pretty busy time, too.
Yes, the first years were very busy, ‘22 and ‘23.
When you think back on these years now, what is it then that you think of — it is the people who were here; there must have been a very great variety.
Yes, many of the people. There were many Japanese people in the first years, also; they were very pleasant people and kind people.
Do you remember Takamine?
Yes. I think he was the first one, and he came here later and had a son born here in Copenhagen. And last year a young man came here to the door, and it was that young man; he has been born in Copenhagen.
Takamine worked a long time here.
Yes, he worked here for many years together with H. N. Hansen and Werner. Then came Nishina, Kimura. Nishina was here I think 7 years. He said goodbye and he went away, and shortly after he came back again; he couldn’t leave Denmark. But at last he had to go back to Japan, because they had found him a wife there; he had to go back and be married.
Maybe that was what kept him.
He wrote about it afterwards. He said, “You can’t understand how it is here; with you it is love first, and then marriage. Here it is marriage first, and then maybe love.” He was not very happy to go home and be married.
Do you remember whether there were any discussions in this group about prob1em outside physics, too. I mean, about social questions and so on.
No, I’ve not heard.
And when you worked with Bohr in the evenings, would he then discuss such things?
Yes. He spoke about many other things.
And he would tell you what he was thinking of?
Do you remember anything in particular?
I remember one thing. He spoke about the Life after Death, and I was the only person who believed in that. Professor Bohr tried to convince me that there was nothing, and the next morning he continued.
Do you remember how he did it?
He said, “It’s quite impossible; it can’t be.”
And did he say why?
So he did not convince you?
No, he couldn’t convince me, but he tried two days, the evening and the next day.
Did he draw any conclusions from that about how one ought to live one’s life?
No, I think we started about Conan Doyle and such things.
And then how did you get from that —?
Oh, I don’t remember. It was here in this house when Professor Bohr was living here, and one evening Professor Bohr and Mrs. Bohr and I spoke about it.
Did you have any idea why he wanted to convince you that there was no life after death and why he took it up again the next day.
Yes, he took it up again the next day.
Then in later years, he never returned to it?
No. Once we spoke about inheritable properties or characteristics. Professor Bohr thought there was nothing in that. A person’s character was determined only by the way in which he was educated. But I thought not.
But he really thought that everyone could be like him, even?
Oh, I do not know, he didn’t say just that. But he said when a Negro from South Africa came into a cultivated home he could be just like the other people.
But you did not agree?
Not especially because it was a Negro, but I mean there is something which children have from their parents. Even if they do not see them, they have nevertheless something of their peculiarities.
Did you often have discussions with Bohr about such things?
No, no. It was in the nights — when we worked in the nights, and had tea afterwards. Then it came.
You always had tea afterwards? What kind of tea? Just ordinary tea?
They tried to give me Kamillete [chamomile tea], but I said, “No, I’m not sick.” Did you get chamomile tea when you were serving there?
No, I never got that. I think it had been canceled after Pauli.
Mrs. Bohr took chamomile tea every night; and for Professor Bohr it was just the same, but I didn’t like it.
Did he have something sweet?
Yes, ‘kiks’ [biscuit, cracker] and such things, or smorbord [open sandwich].
He was fond of sweets?
Yes, I think he was. In the day time he went over to the baker over there sometimes and bought such a great sack of bread for the afternoon tea here, before we had that lunch room over there.
Some smakager? [cookies]
No, the big weinerbrod [danish pastry]. He liked that, yes.
It wasn’t good for his teeth.
No, but he had his teeth nevertheless, until he was an old man.
He had also a good dentist, probably.
Yes, of course.
Did he go to the movies often with the young guests who were here?
Yes, I think during the years when Weisskopf and Gamow and some other people were here, they went to movies. Especially when (Anny Ondra) was there. She was quite young, a big star, and he liked her very much. He went to all her movies.
What kind of star was she?
Oh, a little comical mostly.
That was the chief entertainment in the evenings? What other sort of entertainment was there in the evenings?
He worked also in the evenings; when there were no guests there, then he always worked.
And the guests would usually also be physicists.
Sometimes also other guests were there, then he couldn’t.
The atmosphere at the Institute must have changed a great deal according to who was here?
Absolutely. It was a very comfortable atmosphere in many of the first years. It was like one great family; it is not like that anymore. Now it’s just a great factory.
What sort of things did the family do together? Did they have outings and so on?
No. They came together in the evenings in their homes and they went to movies and sometimes went into the forest and so on together — many of them. Gamow and Weisskopf had motorcycles. They went out with Professor Bronsted’s daughters very much. He was living here at the Institute and had two daughters. After Mrs. Maar we had a Miss Have who had the pension, and many of them lived there. And sometimes there was such an evening company there. Pais and (Bothe) — Rosenfeld was also there.
Do you remember Landau?
Yes, I remember him and his red coat. He went around in such a short red coat, like a postman.
Did you get to know him?
Yes. Not so much. I knew everybody at that time.
What kind of jokes would he make?
Oh, they played ping-pong in the evenings in the library. There were great holes in the floor and in the table afterwards, because they played ping-pong every night.
Not in the day time?
Oh, yes they did, but it was mostly in the evenings.
When did the ping-pong start? How early? When did the table come?
I think it was about the time of Gamow and Delbruck and Weisskopf and Placzek, I think.
Did they have other sports before then that they did?
I do not remember. I remember one thing; it was not just sport. They had been somewhere and came to the lakes over there [two blocks in front of the Institute], and they — Casimir and Weisskopf — bet whether Casimir could swim across the lake. I think for 5 kroner. And he did with all his clothes and shoes and everything. He swam over the sea in the night.
When I was at graduate school in physics, there was always either a ball game after lunch or something like that. Did people play like that?
No, I don’t think so. Not here in the daytime.
And were there annual outings? A picnic where everybody came together?
Not every year. Of course there were some Congresses here, and then they went out in buses to North Zealand and ended in Professor Bohr’s summer house in Tisvilde.
Did you go out in the summer house too in the summer to work with him?
Where did you stay then?
I stayed in Professor Bohr’s house.
Then he was together with the children.
I went out in Tisvilde woods walking with one or two of the boys.
Did he spend much time then in the evening with the children?
What did he do with them?
Oh, he walked with them, and played ball or chopped wood.
Did he make wood cuts too?
No, I have never seen it; I do not know.
Did he ever read to you? I mean as an entertainment, did he read novels or poems to you?
I only heard it very few times in Tisvilde. The children were not very big at that time.
And he would read to them too?
What kind of things would he read?
I don’t know.
But not children’s stories.
But for you, too, for the whole family.
No, no. It was only when I was there alone and the children were there and Mrs. Bohr. And Professor Bohr’s mother was also there sometimes.
Would he read from the Icelandic Sagas?
No, that I never heard.
Did he read Schiller?
No. It was something more for the children, I think.
Did you play cards out there in the evening, too?
No, but I remember Aage played chess.
With his father?
Yes, and Aage tried to teach me chess when very little.
I have never seen Bohr play chess.
Oh, I have only seen it once with the children out there. It was not very earnest I think.
And then some of the guests would come out too to work with him?
Yes. I think Rosenfeld was there many times.
But now the Institute has become a factory you say.
Gradually you took on other duties and left many of the jobs that you used to do for Professor Bohr as the Institute got larger.
It was necessary. I couldn’t take all of it. For the first 16 years there was only me, then it was too much.
When you think back on the years, are there any curious stories which come to mind?
No, I don’t think so.
When the war approached, then — also in the years before — many refugees came up. Did the atmosphere change then?
Was it still a happy family?
Yes. There were not so many who came here. There were many who the Committee helped in some way, but there were not many here. There were Hevesy and Franck, Rozental and the two ladies, Hellmann and Levi.
In the war time when Bohr was still here, how was he then? Did he feel quiet, or could you feel that he was —.
No, he was so quiet, yes. I asked him two days before he left whether he would leave himself and he said, “No.” And two days after he was away, and when he came back he said — I was there for a dinner –- “You must have thought it very curious; I have thought of it many times. I said I would not go away, and two days after I did.” But it was after a special warning that he went away. It had not been his intention. It was the worst time of the Institute.
Did you feel worried yourself about it?
Yes, of course. We lived here. I had to move, and the soldier sat there in my office.
Some people were put into jail and forbidden to work.
Yes. Olsen, the mechanic, and Professor Boggild were taken the first morning when they came.
But you were not?
No. Because I had nothing to do with the apparatus, so I couldn’t make any sabotage for them, and therefore I got to go free.
Then Heisenberg came here to —
Yes. There was another man who came here. I think his name was (Schisch); he came on his way to Norway and spoke with Moller, and he had not heard anything of the occupation of the Institute, and the German physicists did not know anything about it. Then he went home and told it to Heisenberg, and then Heisenberg tried to come up and help, and he did. Then the Institute was made free.
So the big change in the Institute was before and after the war. Then things were different after the war. The first years after the war, then?
Because soon after Professor Bohr came back the great building was erected, and there was so much about that and many people. It was something different.
So you were here at the best time of the Institute?
Yes, absolutely. There was very much to do, but nevertheless, it was the best time, the first years.
You say you worked too much with Bohr in the evenings, so it was also some sacrifice on your part, but in general when you look back on this long time, how do you feel about it?
I feel well. I think it was an interesting time, of course. And Professor Bohr lived here in this house, and the children were here every day, and I saw from the very beginning. I saw Aage from the time when he came from the hospital 10 days old. I was sitting here and working with Professor Bohr and he said, “Have you time to stay a little more, then you can see the new little boy.” It was Aage. There were only Christian and Hans when I came.
Did you find any change in Bohr’s personality as the years went by?
He was always the same.
And if somebody asked you, “How was he?” what could you say?
He was wonderful, I could say. He was the most wonderful man I ever met; always kind to everybody and tried to help all people and never said a bad word about people. Will you make a book of these interviews?
No, no, they are not to be published, but are only for historians to see how people lived and worked.
Maybe I could ask you one more question. Do you remember when Rutherford was here?
I remember I think it was when we were in (the Laerenstalt) — no, it was —
He was here twice, wasn’t he?
But the first time he was here because he should be Doktor honoris causa and then I helped him write that little bit he should give into the University about himself.
How was he, compared to Bohr. Was he like Bohr?
No, he was more gruff than Bohr.
Did he also smoke a pipe?
I think he did, yes.
He was Bohr’s teacher in a way, so it would be very interesting to hear how they were together. I mean, when they were together, how —?
I have never seen them so much together. Professor Bohr told me that Rutherford would like to have something written. And then I went home — Professor Bohr lived in Stockholmsgade with his mother at that time, before the Institute was quite finished — and then went up there and wrote this thing for him. So it must have been in ‘21.
Were you somewhat surprised in the beginning to see the way Bohr worked when he worked?
Yes, because I have been in an entirely ordinary office with a very kind director. I liked him, but he did not say, “Good morning,” every day. But Professor Bohr came up to me and shook hands every day. It gave me the greatest impression from the beginning I think; he was so polite.
And then there was the way he worked –- always having to speak to someone while he worked.
Yes, but I couldn’t compare it with anything else, because I had never worked for a scientist before.
But didn’t it somehow seem strange that it all came out as he talked, and that otherwise —. I mean, didn’t you imagine that he might spend his time sitting thinking in his office and then writing this up?
Yes, it was something quite other than what I was accustomed to seeing. But he went round and round and that made it difficult to hear what he said.
Did he speak as softly then as later?
Very softly and he spoke and with his boots squishing all the time. And the streetcars disturbed. But nevertheless I wish we had him still here.
Did he speak to you about art sometimes?
No. Not so much, because we had not the same taste. I think these things of Mogens Andersen which Professor Bohr put up were dreadful.
But Bohr did not think it was so dreadful, you think?
Oh, they had put them in my office, and Professor Bohr said to somebody else, they had to move them because Mrs. Schultz doesn’t like to look at them. And now it is in the lunchroom.
I remember that day when they had moved them, and you said that it looked like a truck tied to a factory chimney, or something. And then Bohr said –- do you remember that –- that the difference between Greek art and modern art is that in Greek times all the work was supposed to be done by the artist, but in modern times all the work is left to the spectator.
Yes, and I don’t think that’s a good thing. I once asked Mogens Andersen if anybody could see what it means, what he paints. He said, “Yes, my children can.” I think nobody else can.
But did you have the impression, Bohr liked paintings like that?
But I didn’t have the impression –- maybe I’m wrong –- that Bohr was particularly impressed with modern art. Do you think so?
No, it was so that Mogens Andersen was a friend of his eldest son; his interest in Mogens Andersen stems from that.
But I remember he told that he had had a discussion with Mogens Andersen, and Mogens Andersen had pointed to something –- I don’t know what, a shell or something, some natural thing, and said that this was the most beautiful art that one could have, one could imagine. And Bohr said that this was not art at all, because in order to be art it must be formed by a human; one must be able to see or to feel the human hand behind it. So I don’t think that Bohr would consider abstract art in itself as —. I don’t remember; I don’t know. You probably know better than I. He liked Cezanne; Bohr’s favorite painter was Cezanne. I have often heard him say that nobody could paint better than Cezanne.
I think he liked also (Scharff’s) way of painting.
But that is also, I think, somewhat related to Cezanne.
Yes, it must be, and they are nice colors. Mogens Andersen’s colors are not nice.