Alan Holden - Session II

Hoddeson:

I’m looking at an article by Alan Holden — “Artistic Invitations to the Study of Physics” — that Alan says is full of euphoria. ^[1]

Holden:

I think that you can read in that the joy of a man receiving a prize. He thinks he’s pretty great for a while and there he was, that’s what he sounds like.

Hoddeson:

In the first session of our interview, some two years ago, I did not ask you very many questions about your early background. I’d like to begin today with an attempt to fill in some of that information. You were born in New York in 1904. Where did you live?

Holden:

About the corner of 131st St. and Lexington Avenue. My parents moved to White Plains in a couple of years and built a house there, and my earliest memories are in that house in White Plains. And I went to grade school at the Roger Ascham School, which was a private school in Scarsdale not too far from where we lived. Then my family moved to Montclair, New Jersey, just as I was about to enter high school. So I went to Montclair high school for four years and then went to Harvard.

Hoddeson:

What did your father do?

Holden:

He was a sales manager for the Mason Box Company in a New England box making concern, which made paper boxes, mailing boxes and jewelers’ boxes, fancy paper boxes, things of that kind. He ran the New York office, which is to say an office consisting of himself, and one assistant and a secretary. That was what it was.

Hoddeson:

Did your mother work?

Holden:

No, she had been trained as a kindergartener but she never worked as one after she was married.

Hoddeson:

And did you have any brother or sisters?

Holden:

I have two brothers, both younger. We were spaced eight years apart, so each of us behaved pretty much like an only child, you know. My next younger brother is a professor of music at Mount Holyoke College, a musician and composer, and my youngest brother I’ve lost track of completely, I don’t know where he is.

Hoddeson:

Where do you believe your scientific interest came from? Do you recall any specific events in your childhood, in your education perhaps or in your relations with your friends or relatives that may have contributed?

Holden:

Well I think the nearest thing I could point to, though I’m not sure how much of an influence that really was, was the fact that my paternal uncle was a mining engineer and a professor of mining engineering at the University of Wisconsin. That’s a connection of a sort, and as I began showing an interest in science he loaned me little books, things of that kind.

Hoddeson:

Was this while you were still in grade school?

Holden:

Yes, I began getting interested when I was very young, in chemistry in particular. I would put vinegar on chalk and watch it sizzle and so on, and be absolutely delighted. Wondered why it was that — since they told me that sulphuric acid was H₂SO₄ — if I mixed up sulphur and oxygen and hydrogen I didn’t get sulphuric acid, which I jolly well didn’t. And things like that.

Hoddeson:

Did your little brother participate at all in these little experiments?

Holden:

No.

Hoddeson:

You worked alone?

Holden:

Alone yes. No, you see eight years younger he hardly could.

Hoddeson:

And then this interest, I guess, continued through high school.

Holden:

Oh yes.

Hoddeson:

And right into college.

Holden:

Right, straight through.

Hoddeson:

Were there any teachers who played a major role in high school or earlier?

Holden:

I don’t think so.

Hoddeson:

When were you sure that you were going to follow a scientific career in chemistry and physics?

Holden:

I was really sure that I was going to follow a scientific career when I went to Harvard. I was less sure that I was going to do so when I left Harvard. And in fact then I spent ten years out of science. Five of them as a business methods investigator at Bell Laboratories and five or six of them as a publicist. By that time I was jolly sure that I was going to be a scientist all over again.

Hoddeson:

Most of your writing had to do with research that was going on at Bell.

Holden:

I suppose, yes.

Hoddeson:

Getting back to Harvard, how did you make the decision to go there?

Holden:

Well at the last minute I had been going to Dartmouth and a friend of mine at Montclair High School who was going to go to Harvard, said “Oh you don’t want to go to that place, come on let’s go to Harvard.” And I said alright, sure. And I guess I still had time to take the comprehensive examinations in order to get admitted to Harvard. I had been going to go to Dartmouth on certificate, which you could still do.

Hoddeson:

And this is about 1920 or ‘21.

Holden:

Yes, it was ‘21.

Hoddeson:

And did you take courses with any of the well-known people who were at Harvard at that time, such as Van Vleck, or Slater?

Holden:

Slater wasn’t at Harvard at that time, and Van Vleck was still out in the West, or in the Middle West.

Hoddeson:

I believe they were both graduate students at that time, in the physics department at Harvard. And so of course you wouldn’t have known them.

Holden:

Slater was either there as a graduate student or just left as a graduate student.

Hoddeson:

I think he left in ‘23. Did you take some physics courses or were you focused entirely on chemistry or —

Holden:

Well I was focused almost entirely on chemistry, but was more interested in physics then most of the chemists seemed to be. I did take courses at Harvard in the physics department with Kemble and that very charming viola player and later in violin acoustics, Saunders. And with an X-ray guy, ^[2] and that’s it I guess. I tried to take a course with Bridgman but it time conflicted with one that I really wanted to take in chemistry and I couldn’t do it.

Hoddeson:

Did you study with any chemists?

Holden:

Well I don’t know. After all Mr. Conant became rather eminent. He was Assistant Professor Conant at that time. I took his course in organic chemistry. I took the physical chemistry course with Richards and analytical chemistry course with Forbes — those are gents and names that come to mind. And Kohler, the advanced organic chemistry course was Kohler. E. P. Kohler I don’t know how eminent he is. Not pretty well known among the organic chemists in this period. But I ranged modestly widely around the college. They almost didn’t give me a degree.

Hoddeson:

Why?

Holden:

Because I did the kind of thing that I think many smart young fellows probably do, or did do, I don’t know. Signed up for courses which I didn’t really take and then took courses that I really didn’t sign up for. That kind of d—- thing. And so at the end of things they told me that I had not completed enough credits for the degree, and then I rustled around among the professors whose courses I had sat in on and taken most religiously and carefully, and completely but had never signed up for, and when they put in a word for me they gave me a degree Cum Laude. College credentials what you make of this kind of thing. I don’t approve of playing fast and loose with college that way, but I did it. I can’t recommend it.

Hoddeson:

Did you have any jobs along the way, either in high school or in college, summer jobs perhaps, that related to your career directions at all?

Holden:

I didn’t have any summer jobs related to science. I had little jobs of various kinds.

Hoddeson:

Who supported you in school?

Holden:

My family.

Hoddeson:

Entirely?

Holden:

Yes. Well I got some scholarships, the first two or three years of college. They weren’t big but they helped.

Hoddeson:

And also earlier when you went to private school.

Holden:

Yes then, I don’t know the ins and outs of that thing. That was a private school which was founded by our next door neighbor in White Plains, who had been an old friend of the family and I went to the thing. I almost had to because they were such close friends with my family. Now, I dare say the Allens made special concessions for me, I don’t know, financial concessions, I just don’t know. I wouldn’t have been told at that age.

Hoddeson:

Was your high school career somewhat unconventional also?

Holden:

That was pretty straightfoward. That was a public school. It was Montclair High School. The only remarkable thing about the public high school was that I was the editor of the high school paper in my senior year, but that’s it.

Hoddeson:

I imagine you probably became a little bit aware the new developments in atomic physics while at Harvard. Harvard was one of leading American institutions for physics in the early part of the 20th century. Did that enter into the undergraduate courses that you took?

Holden:

Well, as I guess I mentioned to you I sat in on this course that Kemble gave in quantum theory, which was the first such course I think they gave there, and I mentioned perhaps, that I might be able to find the notes that Kemble made for that thing. And I haven’t looked them up yet I’m sorry to say. They would now be yellowed mimeograph things. I can do it. Now apart from that, some of the early pre-quantum – pre-wave mechanical, of course this is all pre-wave mechanical, I graduated in 1925 — that X-ray course, needless to say, had something to do with this material. Not much oddly enough. It didn’t, as I recall it, even talk about Bohr orbits or anything of that kind. It just talked about energy levels and left them unexplained. It was in short a pretty empirical sort of course.

Hoddeson:

What made you then turn away from the idea that you wanted to do research in a scientific area?

Holden:

I guess, a rapidly growing interest in literature, mostly that, music perhaps — the feeling that there was something awfully restricting about scientific work I think must have gone into this. This all probably has to do with the fact that the chemistry courses one was taking all involved quite a lot of laboratory work; they had a very pre-professional air to them. They were solid work, and I got very much the feeling, I remember it well, that if I went into this as a life work, there I was, lodged in a laboratory able to think of nothing but the scientific work that I was doing — able to, simply from the point of view of time and attention. And Harvard had brought my interests tremendously beyond that, so I had the feeling “Gee some other walk of life may enable me to lead a broader life.”

Hoddeson:

And yet, when you began to look for a job you did lock for a job first as a chemist.

Holden:

Yes, that’s what I was trained as.

Hoddeson:

Did you look anywhere else besides Bell Laboratories?

Holden:

Oh yes, yes. Bell Laboratories is where I ended up. I looked elsewhere; I had a lot of letters and introductions to all kinds of places and people.

Hoddeson:

How did you go about looking for a job?

Holden:

Mostly by letters of introduction. Kindly friends and relatives and their friends and relatives and things of that kind. Not necessarily very powerful but just something with a personal word in it that would introduce one somewhere.

Hoddeson:

Well anyway, then you got to Bell and we’ve covered your early work in Accounting and Publications briefly in the first session. What I did not get clearly in the first session is the nature of your interactions in that period with other people at Bell. For example, with members of the research staff between 1925 to 1936 — particularly in the last few years when you were writing articles on research. You must have gotten to know almost everybody.

Holden:

Oh no, not almost everybody, but a fair number of people. No, you see Bell Laboratories consists mostly of electrical and mechanical engineers, did then, does now, will even more in the future, I think. And rightly so, that’s what the job is. So as one of two people editing pieces for Bell Laboratories Record, I was mostly editing things by electrical engineers and mechanical engineers. And that didn’t acquaint me very broadly in the research area. I got to know some of these people. And I was always given, or took, the chemistry articles to edit, so I got to know the chemists moderately well.

Hoddeson:

Well, who for example?

Holden:

At that time, Bob Waterman, who was instrumental in getting me into the chemical department later.

Hoddeson:

(Brings out chart) This is a chart of January ‘38 chart, of the entire research department. In chemistry the leader is R.R. Williams, and below him we have Harris, Kemp, Burns and Schuh.

Holden:

Yeah, Bob Waterman would have been under Burns. I think —

Hoddeson:

No he’s not here, I have a ‘37 chart of the chemical laboratory and oh here, Waterman is down under Kemp. What was the nature of your interaction with Waterman?

Holden:

I edited a piece of his. And he was a friend of another chap I knew. That’s about it. And somehow we hit it off pretty well. And after they began to be able to move people around the laboratory after the depression freeze — all the departments were 1ookng to replenish their staff even at the expense of other departments — Bob Waterman said to Williams that he knew this little chap in the publication department who seemed to know some chemistry.

Hoddeson:

Did you get to know Fletcher?

Holden:

Fletcher somewhat, yes.

Hoddeson:

Would you talk much to Fletcher?

Holden:

No not really. I always found Fletcher kind of an unapproachable sort of a cuss. He was, later in my career there — career is the word to use isn’t it? –- I think he was my boss, or my boss’s boss. But I don’t think he ever paid me a great deal of attention.

Hoddeson:

How about Arnold? Did you know Arnold?

Holden:

I didn’t know Arnold, no, I never met him.

Hoddeson:

Buckley?

Holden:

I probably met Buckley, that’s about it. Not much more than that.

Hoddeson:

J.B. Johnson?

Holden:

J. B. Johnson, I knew a little better. He became Fisk’s first boss by the way. Nice man, J. B. Johnson.

Hoddeson:

Let’s look at some of the people in chemistry. Going back to the chart in ’37, here you are working under Kohman, along with Egerton. Do you remember what you were working on at that time?

Holden:

The general situation in my earliest time there was that the chemistry department was to a remarkable degree an odd jobs department, and I did quite a lot of odd jobs. I can describe the sort of thing I mean, if you like. Do you like?

Hoddeson:

Yes.

Holden:

You do.

Hoddeson:

I’m trying to get a feeling for the general research environment.

Holden:

There came for instance requests from the vacuum tube department for somebody to make a bunch of co-precipitated carbonates of the alkaline earth metal to use as vacuum tube coatings. As you may or may not know, in those days, and I guess today, the major coatings on vacuum-tube filaments, so as to enhance emission of electrons from the filaments, were alkaline earth oxides obtained by firing alkaline earth carbonates on those filaments. And there were all kinds of mystical businesses about what kinds of combinations of alkaline earths you wanted on those things. And also what their physical state ought to be, finely crystalline or whatever. How were you going to get that kind of situation? And somebody from the General Electric Company had figured out a peculiarly effective recipe for this stuff. And somebody else had tried to follow it and had failed to get anything remotely satisfactory. And so they asked the chemistry department to make up a big batch, according to this recipe. And the chemistry department asked me to do it, and I did it. This is sort of a production job. To precipitate things at a certain rate and a certain temperature, and washed in a certain way, this kind of business, and you dry at a certain heat — nobody knows why but you do it. And I was told, I think some twenty years after I did that job, damn near twenty years, by somebody in the vacuum tube department, they’re still using that batch of stuff. It was marvelous, nobody ever managed to do it again. They hoped they’d never have to, so on and so on. I made a h—- of a lot of it. And, well that’s odd jobs. What does it require? Well it does require a certain sense of — it means that you’ve been around a chemistry laboratory that’s one of the things it means. It means the most elementary things about being around chemistry laboratories. It means when you pick up a heavy piece of glass that you don’t drop it, break it, for example. Some sense of how to keep the d—- thing from getting contaminated, some sense of what kind of filter paper is going to do the best job on this particular job. That kind of thing. And I had had an awful lot of laboratory experience before that, at Harvard, and before that too.

Hoddeson:

Where?

Holden:

In my high school. I loved the chemistry laboratory in high school, I played a lot of games —

Hoddeson:

Let’s go back to that.

Holden:

— Played games in that with the chemistry teacher, who enjoyed playing games and who liked to have a high school boy who liked to play games. And did things in the laboratory.

Hoddeson:

For example.

Holden:

For example, we made a batch of seleniumy oxychloride, and distilled and purified it and things because he had read somewhere that seleniumy oxychloride would remove print from paper. And it will. We made it, we found it would, yes, they were right. But really the reason we were doing it was the kind of thing that goes I think probably into a young man’s interest in chemistry, which is mud pies. Preparative chemistry is a lot of fun, and gives you a strong sense of reward. I enjoyed, I kept right on exploiting it and enjoying it, right up through my physics career. I worked with Charlie Kittel once, much later making solid organic free radicals, for example.

Hoddeson:

In what connection? It must have been in the late ‘40’s.

Holden:

Yes, the late ‘40’s. This was for experiments in microwave absorption. Organic free radicals have an unpaired electron, and you can put a fixed magnetic field on them, polarize them, and then a varying microwave field on them and flip them. And by finding what frequency they flipped, at what applied field, you can find out something about the bonding which held those electrons there in the first place. So these things which have been pursued considerably since then, in a number of different ways, were among the early experiments that were done. Charlie’s and my experiments were among the earliest experiments that were done on microwave absorption in organic free radicals. Well I had a lot of fun making the free radicals. That was preparative organic chemistry.

Hoddeson:

I see you also worked with Merritt and Yager on these experiments.

Holden:

Yes.

Hoddeson:

There are some papers here with all four of you as co-authors. They’re all in ‘49 or ‘50.

Holden:

Yes, you’ve got the dope there pretty much.

Hoddeson:

But so in that group you were then the person who actually made the materials.

Holden:

I made the materials. I also dreamed up materials, so to speak. I mean — “hey, let’s see about it, what materials shall we make?” And in some cases I made a few new free radicals that had never been made by the organic chemists before! I dreamed them up. And that was all in good fun. Then Yager and Merritt were the microwave apparatus people.

Hoddeson:

And Kittel was —

Holden:

— a theorist. He’s entirely a theorist.

Hoddeson:

He played no role at all in experiments?

Holden:

No.

Hoddeson:

Who set up the microwave resonance.

Holden:

Yager and Merritt.

Hoddeson:

Under Kittel’s direction?

Holden:

I don’t think so, no. I think Bill Yager is amply cable of setting that up, you know.

Hoddeson:

Who designed the experiment.

Holden:

Bill did.

Hoddeson:

I’m trying to figure out how the group got together. Here’s a good example of one of the groups we were talking about earlier in chemistry, and some in theory —

Holden:

The group got together initially over — I don’t know. We did a job, and it was in that inorganic single crystal field that we got together because before Charlie Kittel joined the Bell Labs he had written a theoretical paper with Quin Luttinger on what resonances were to be expected in well if not chrome alum, then in chromium compounds or maybe nickel, single crystal form, how the crystal field would split these things so that you would have a fine structure in the microwave absorption. He and Quin had written a paper on this for Physical Review and I knew it, so that when he came and settled in there a while I said Charlie you know, all this nice beautiful elegant theoretical work, and nobody’s done any experiments on the G—- d—- things and that isn’t right is it? Shouldn’t we really do something about it, see whether you fellows are right or not? And I said Bill Yager might be interested in this; he is getting interested in microwave transmission. So, perhaps, I think, I was the agent provocateur on that get together beginning with those things. Then after we had done some work on a few crystal types, and I am surprised there isn’t something there, maybe there is and maybe there isn’t, about the fluosilicates; something about nickel fluosilicates, maybe not. Anyway, we did some work on it.

Hoddeson:

The same group?

Holden:

Yes. The same bunch. Then at some stage of the game looking through literature of various kinds, Charlie or I, or us together sitting like that, ran across — it was in Landolt Bernstein’s tables — ran across a mention of a chemical compound with a very long name and after it — Bernstein — was the legend (Latin used here)… Charlie, I think, probably said, “Why don’t we try it and see if we get resonance.” So we did and that was the first organic free radical that we examined. Then Charlie found out that Zavoisky, unknown to us, and we unknown to him, had done this at about the same time on an entirely different compound which was also an organic free radical.

Hoddeson:

When you were working in this group with Kittel, Merritt and Yager, did you speak with Kittel on a daily basis?

Holden:

Pretty much.

Hoddeson:

Was he interested in the chemistry?

Holden:

I don’t think Charlie cared much about the chemistry of the thing. Well, it’s not quite fair to say that Charlie was not interested in the chemistry. We found, for example that these free radicals gave absorption lines which were fantastically narrower than the inorganic materials had. Now, Charlie was concerned about why the h—- that would be so, and he developed a little bit of a theory of exchange narrowing having to do with those lines which really required him to examine somewhat the chemical basis, the chemical structural basis, for exchange narrowing. And I would kick around with Charlie what the chemistry said about bond lengths, what it said about electron localization in those bonds and things of that kind; questions of whether or not an electron might have a considerable probability of jumping to another molecule, such questions. We would kick them around.

Hoddeson:

Was this interaction an outgrowth of your having been part of the famous solid state physics group under Morgan and Shockley that I am particularly interested in?

Holden:

I remember quite well that when we found this extremely sharp narrow line in one of those organic free radicals, we promptly told Bill Shockley, who was a co-director of that group as you know. Bill was excited and immediately called up Ralph Bown, I guess, and said, “Come on down here and see this. We need an audience.” So Bown did. You know, he came down and admired this very sharp line on the spectroscope.

Hoddeson:

How did you feel working under Shockley and Morgan in that group.

Holden:

I felt fine about it. I had a wonderful time.

Hoddeson:

Were they aware of the details of your work?

Holden:

I would say that, yes, they were. They were abreast of certainly what they needed to know in order to have a general understanding of the thing. The details, maybe and maybe not.

Hoddeson:

Did they guide your work in any way that you felt aware of?

Holden:

No. I would say that neither of them did guide that work.

Hoddeson:

Now, your work on piezoelectric materials was later wasn’t it?

Holden:

Before.

Hoddeson:

Before. The publications…

Holden:

I didn’t publish much on piezoelectric…

Hoddeson:

There is something in ‘47, oh just a Bell Labs Record piece. There is an article in ‘O, when you worked with Mason, Kohman, and Morgan.

Holden:

That’s the heavy water one.

Hoddeson:

In ‘39.

Holden:

Yes. Morgan had suggested that quite awhile back when heavy water first showed up. And that was his reason for being on that thing. He had made an initial suggestion about it and Kohman and I did — I grew the crystals and then Kohman and I did the dielectric measurements and then we shot stuff over to Mason who made some piezoelectric measurements and things.

Hoddeson:

In a group project like this how is the paper generally written?

Holden:

It varies quite a lot. You mean who writes it?

Hoddeson:

Yes.

Holden:

Well, somebody usually has to write the thing. Then you send it around for comments and criticism.

Hoddeson:

Were you close to Mason?

Holden:

Fairly, if anybody was. Mason is not the kind of guy you get close to. At least that was true in my experiences and I think Walter Bond, who was probably closer to him than I was, would say the same. I was kind of thrown close to Mason constantly by the collaborations I think — the succession of operations which involved me and then Mason, you know, in growing new piezoelectric materials and handing them over to Mason for measurement.

Hoddeson:

How about Morgan?

Holden:

I would talk about things with Morgan much more than I would with Mason, because Morgan is a much more approachable person. Partly I suspect that Morgan was a man who no longer had his own fish to fry. He interested himself in what other people were doing. He stopped his research in dielectric materials when he became a group head. I think it is very hard for a supervisor to show that kind of interest and at the same time have his own research going.

Hoddeson:

Well, at about the same time that you worked with Kittel, you also worked with Townes —

Holden:

… a little bit earlier

Hoddeson:

— on microwave spectra.

Holden:

There what I was doing was entirely the preparative side of the thing.

Hoddeson:

You are working with Merritt, on several papers. There is also one with Bardeen on it.

Holden:

That’s quadrupole moments, yes. I didn’t realize that Bardeen was in on that quadrupole moments thing. Certainly I didn’t collaborate with him. Townes was the unifier of that thing. I don’t remember what that was about.

Hoddeson:

In your interactions with Townes, did you discuss the physical basis of the work?

Holden:

Sure. I would discuss the physical basis of the work with Townes. There was pretty close interaction with Townes. He was a pedagogical type and likes to explain things and I was eager and curious to find out about things. Apart from the preparation of the materials which went into these things, which was always my responsibility because I was the only guy in the whole d—- bunch who gave a hoot about making something — making things — the only mud pies plainly in the whole show. Apart from that, I would get caught up by some aspect of the thing and do at times a lot of the numerical calculating that had to be done in the job too. I did do a certain amount of deciding that things ought to be made to accomplish certain things that Charlie Townes wanted to do. How can I describe that? Well, you don’t need to describe, you can kind of imagine that. What sorts of compounds were accessible which would present a cylindrically symmetrical electric field at a nucleus of such and such a species? Well, all right. Townes doesn’t know any chemistry or d—- little at that time anyway, probably knows more now. And I would say, “Gee, it strikes me that this is the kind of thing that you are probably talking about. And one can make it in the following form, I think.” And he would say, “Well, great. Look into the question of whether you can.” And that kind of business. So, we want to examine, let us say, some molecules which are linear. “What have you got to contribute in the way of linear molecules which still have a dipole moment so that we can get a hooker on it for a mark?” So, you dream up something linear, well, carbon, triple bond carbon, hydrogen on one end and chlorine at the other, how about that? Great! Can you make it? Pretty stinky stuff to make.

Hoddeson:

Did Townes look you up in order to do this?

Holden:

You mean, how did our stuff get started? Let’s see. Townes had been doing war work which involved microwave transmission, radar work. And as he played with those radar things and he thought, as a good many of them probably did think. You know after the war I am going to do something with these d—- things of a scientific kind because they are spectroscopic tools in a new region of frequency, and now we have all this stuff tooled up and it’s possible to do something. They wouldn’t release him from his work for quite awhile. But he had built up quite a pressure, an internal steam, to do this. But I am just not certain now what connected them with me except that we knew each other well by then. I might have been the only one who was free. I may have said, “Well, come on let’s go, soon as they will let you do it, come on let’s do something about it.”

Hoddeson:

What did you do during the war?

Holden:

I was working on ADP, piezoelectric materials. You know the ADP story?

Hoddeson:

No. Tell me.

Holden:

Large single crystals of ammonium dihydrogen phosphate were in demand by the Navy as piezoelectric materials for underwater sound devices. And the Western Electric Company agreed to manufacture these crystals and the problem was to set up a factory for making large single crystals of ADP, which nobody knew how to do. They agreed to do it, but… And I had been working on piezoelectric crystals at that stage of the game that was what I was working on entirely as the War broke out and either was detailed or detailed myself to do the thing. It was the obvious thing for me to do, to try to get something together which would work in that area, and so that’s what we did.

Hoddeson:

Did you continue to work in the same laboratory at Bell?

Holden:

The same laboratory, yes. When the thing started to get in production out in Chicago, the Western Electric Company Plant especially put up out there to do this. I spent a time commuting between Chicago and Murray Hill, two weeks out there and two weeks back here, that kind of shuttle, supervising the installation of that thing and getting it so that it would work and then coming back here and growing seed crystals to put into it, and then going back with new information on impurity effects and worrying about the more and more refined problems which arose in connection with it — impurities that began to be ingrown in the crystals and increased their conductivity.

Hoddeson:

And after the War?

Holden:

Well, after the War, I used techniques which I had worked up in connection with the ADP job to grow large single crystals other things, piezoelectric things, in the hope of finding a satisfactory substitute for quartz which had always been the reason why I was working on piezoelectric things in the first place.

Hoddeson:

I didn’t know that.

Holden:

That was the motif behind that piezoelectric stuff. That was stuff that I started when I first joined the chemistry department. They asked me to look around and see what kind of work I would be interested in doing for the chemistry department. Among the things I had looked over were memos that had come in from Heising and Mason on the importance of trying to find some kind of substitute for quartz as a piezoelectric material, the importance stemming from the fact that we were essentially dependent on Brazil for our sources. Brazil could shut them off at any time and could charge any price. That was a dangerous situation. So I said there’s “Open Sesame” and a hell of a lot of fun with crystallography and the preparation of crystals and all the rest of it, and I elected to do this: to develop methods for making decent crystals. And I made them, and then increasingly Mason did work on those things. Well, after the war I got back at that and, I don’t know, perhaps it was another year or after I got back at it, that we came up with EDT, ethylene-diamine-tartrate, as a material which would do the trick. And Western Electric put up a factory at Allentown to make this stuff in great amounts and crank out great big beautiful crystals of the stuff. They then showed a collection of Brazilian potentates through the factories — how beautiful a thing it was, and how beautifully it was going on and the price of quartz came way down. I guess it was pretty quick after that they junked the factory and in the meantime, word of course was coming through more and more about the work that the Germans had done on growing quartz itself. Albert Walker got going on that. And having found the EDT thing, I turned aside from piezoelectrics and Albert carried on the stuff on quartz, very triumphantly, as you probably know. They now grow their quartz so far as I know, all of it. I don’t believe they import any quartz.

Hoddeson:

From Brazil?

Holden:

From Brazil or any other place. That quartz development is beautiful.

Hoddeson:

Do you recall your reaction to the invention of the transistor? Do you remember first hearing about it?

Holden:

I don’t recall my reaction. I don’t remember just how I heard about it.

Hoddeson:

Were you aware of the work that was going on?

Holden:

Yes, I was aware of it but not in detail though, just that it was going on. Over tea, Bardeen would talk about the theory, which before the transistor was discovered was wildly wrong, of course. The fact that Walter had a thing there that amplified. I don’t seem to recall at all, how and when.

Hoddeson:

We are returning from a short break. While we were not recording you told me about your work on the rotating crystallizer. Was that an outgrowth of explorations that you began during the War?

Holden:

Right. How to grow large single crystals, which isn’t an easy job, at least not a very easy job. At that time it wasn’t generally known how to do it. I didn’t know either. I worked up, finally after a lot of different ideas, a scheme for doing it, which we called the reciprocating rotary crystallizer. Nowadays, I think, most people who are going to grow crystals from solution use that scheme. And in 1949, I went to Britain and talked about it at a discussion of the Faraday Society on crystal and crystal growing at Bristol. It was one of the Faraday Society’s annual discussions.

Hoddeson:

Were you invited?

Holden:

I was invited, yes.

Hoddeson:

So, the news of your work had traveled to Britain.

Holden:

Yes, news of my work traveled to Britain. I travelled around Britain and found these various crystals being grown by my scheme in a number of places.

Hoddeson:

How did they learn it?

Holden:

They learned it because of the fact that the delegations of British scientists during the war to America had been shown through my laboratory which was essentially a sound idea and enabled them to do this if they needed to do it. So, I found, for example, well, way down in the bowels of Dollis Hill where there was a little laboratory, that was well temperature controlled because of the fact that it was down where nothing that would ever change a temperature could ever reach it. It was a wartime bunker, originally for Winston Churchill, and now they were using it to grow crystals by my method — way down there. And they were doing this also in Paris, and they were doing t in Poole, where the British Naval Service has a laboratory. That’s it. I don’t remember finding any in the Netherlands.

Hoddeson:

You mentioned that the work you were doing during the War got you onto this even though you were using a different method. People often talk about how the War stopped research, and how their research, then began again after the War. But most of the conversations I’ve had, it seems to be that in fact, the War aided their research.

Holden:

I suppose what it did was stop the research of many people who had wanted to be doing some research which they weren’t able to do during the War, and it probably started the research of a lot of other people.

Hoddeson:

Quite a bit of the research that really paid off greatly after the War was started during the War, or at least accelerated.

Holden:

Yes.

Hoddeson:

Think of all the money that during the War was put into making materials that had very small amounts of impurities — more accurately controlled impurities — through the radar studies, for example.

Holden:

Yes.

Hoddeson:

All of that paid off tremendously in research terms after the War.

Holden:

Yes.

Hoddeson:

In your case also… I am wondering whether any generalizations can be made.

Hoddeson:

I don’t know.

Holden:

Now, if you would like me to hunt down that reference of the Faraday Society, I will do so. I am very much surprised that they do not have it there. And of course the other things that you don’t have there now are the books. Do want them or not? I have several books.

Hoddeson:

It would be useful to me to have a list of them to include in the file of material that will be deposited at the Niels Bohr Library with the final transcript is all ready.

Holden:

But you’re in no hurry for that?

Hoddeson:

I’m in no hurry. That would be fine. Is there anything crucial we have left out? Is there some major area of your career that we haven’t touched upon?

Holden:

What have you got? You’ve got microwave absorption stuff over a wide variety of things. That, of course, feathers cut in a lot of different places, quadrupole resonances and all kinds of things.

Hoddeson:

Oh, we didn’t talk about your work on ferroelectrics. Let’s spend a few minutes on that. Didn’t that work become important later on in studies of superconductivity?

Holden:

Oh, I don’t think so. No. I really don’t think there is any contact there. The only connection there was through the personality of Matthias.

Hoddeson:

How did you get involved in research on ferroelectrics? This was in the mid-fifties.

Holden:

Yes, Bernt Matthias was interested in ferroelectrics way back. He knew that I had grown an immense number of piezoelectric materials, in particular, in the form of small samples for preliminary test, and that I had them in bottles tucked away somewhere. And he had said to me several times, “One of these rainy days we ought to get together and test those things for ferroelectricity.” And I said, “Sure, sure, we certainly should.” And we never did. And then later he said, “You know one of these days we ought to get together and test these things for ferroelectricity,” And the first thing we tried, of course, was not ferroelectric. Ferroelectrics are rare. I don’t really think we expected to find any in this collection of 200 or so things. So first thing we tried didn’t show any signs of ferroelectricity and we put that back in the bottle. The next thing didn’t either… and we put that back in the bottle. And the third thing did. And I said, “Come on now, I don’t believe it. Take another sample out of that bottle and try it.” We took another sample out and it didn’t. And I said of course, it’s possible that the first sample was right and that the difficulty is that we are looking in a different direction on this second sample. Let’s see if I can cleave that thing in such a way that we will look in the same direction.

So I cleaved it and we looked in the same direction and it did. That was a ferroelectric. That was a thing later called GASH, guanidine aluminum sulfate hexahydrate. That’s what got us into it. And then, I looked around for some more and he looked around for some more and we did some more work on it. And the motif here, apart from the fact that ferroelectrics are rare and interesting things, was that we felt that there could be a use for ferroelectrics in the telephone plant as memory devices. And, in fact, groups of people in the apparatus department, a group of people there, became quite interested in the idea and tried out some designs using chips of those crystals as memories. And they work as memories alright. Finally, there was a showdown, so to speak, between the use of those things as memories and the use of magnetic devices as memories, and I forget the details of why it was decided to abandon further engineering work on the ferroelectrics. But there was a definite and conclusive reason for this and that took, of course, a good bit of steam out of the thing. I guess that is essentially the story there. Berndt has turned up some more. He got interested in trying out a lot of different materials and he turned up some other ferroelectrics. No more out of that hatch of 200 of mine. Walter Merz instantly ran through tests on all of those things and found nothing more. Berndt had been characteristically lucky running into ferroelectrics right off the bat.

Hoddeson:

There’s an interesting parallel between this story and the one that I heard about Ohl’s discovery of the silicon pn junctions.

Holden:

Yes. That’s right. He made whisker detectors didn’t he.

Hoddeson:

Right. He was interested in high frequency microwave detection. He examined every material he could get his hands on and in the process came to recognize the superior properties of silicon. Then the metallurgists began working to obtain samples of pure silicon. And then Scaff created the first pn junction which Ohl then discovered.

Holden:

Yes, Ohl was sort of like Michael Faraday. He said, “Try everything.”

Hoddeson:

Is Ohl someone I should speak with? He lives in California.

Holden:

Maybe so. He’s an interesting old cuss.

Hoddeson:

You later did some work with silicon in the fifties, spin resonance work.

Holden:

I didn’t do anything on it.

Hoddeson:

You write a letter to the editor of —

Holden:

Oh, Yes.

Hoddeson:

Probably just a suggestion?

Holden:

Yes, I made a suggestion.

Hoddeson:

So, you weren’t involved in silicon work at all then.

Holden:

No.

Hoddeson:

… or semiconductor work in general?

Holden:

Not really, no.

Hoddeson:

Maybe this is a good place to stop for now. We can always continue.

Holden:

Yes, we always can.

Hoddeson:

Can you think of something right now that we’ve left out?

Holden:

No. I don’t.

Hoddeson:

Well than let me thank you so much for this interview today.