Robert Pound - Session I

Pavlish:

Today is September 23, 2006. My name is Ursula Pavlish and I am here to interview Professor Robert Pound about his work in the discovery of Nuclear Magnetic Resonance. Professor Pound, as my main source, I have this article you wrote for The Encyclopedia of Nuclear Magnetic Resonance called “The Early Days in NMR.” In it, you give a very vivid account of the time leading up to the discovery at the end of World War II, including your work in the MIT Radiation Laboratory. You describe the day to day work of yourself, Purcell, and Torrey. My first question is a trivial one. You say: “One hot day in December, Henry Torrey and I invited Ed Purcell to join us for lunch at the small restaurant in Central Square, Cambridge, where we frequently went.” Then you go on to explain the genesis of the idea of doing the NMR experiment.

Pound:

Purcell asked Henry Torrey about his views about whether he thought it could be done, because Henry Torrey had done his thesis work with I. I. Rabi back before the resonance technique had been started. But then, Torrey became a theorist who wrote some of the most analytical things about the resonance technique. He and his wife became mine and my wife’s closest friends during the Radiation Lab days. He was the co-occupant of the same room we called an office at MIT.

Pavlish:

That was the office where you would remain even after the work at the MIT Radiation Lab was finished? You remained on to write the reports on the research that had been done at the Lab during the war? Or did you then move on to [another] office? Because, here you say that you shared an office as well. Did you also share an office at Harvard?

Pound:

No, just at MIT, just at the Radiation Lab. Henry did not come to Harvard with me. I came to Harvard as soon as soon as I left MIT, because I was appointed to The Society of Fellows at Harvard, which provided not bad offices. I was not a physics faculty member, I was a member of The Harvard Society of Fellows; they called me a Junior Fellow.

Pavlish:

Was this a frequent occurrence that you would go to meals together with other researchers and discuss physics questions?

Pound:

Oh yes. There were three persons that I usually went round to see if they were available to go walking up to Central Square. We frequented this wonderful delicatessen that we would go to that made its own bread. It made its own ice cream, and a number of other things. You have to remember that these were days of austerity, because the ration controls of World War II were still in effect. And how they put all that together, I have never understood because our standard lunch was Boston cream pie with ice cream. How did they get all that together to be able to do that every day? We had a ‘waitress effect’ because she always substituted our favorite foods for us when we came in. They usually had a special every day for 40 cents; the 40-cent luncheon. We found that even though sometimes the luncheon we wanted was the 40-cent luncheon, it was not always what we preferred to eat. But we were always able to get that waitress to substitute, and bring us what we wanted.

Pavlish:

So she would give you something else for the 40 cents?

Pound:

Yes. We would get our regular, this special thing that we liked. But the other two persons that I went with (Purcell was not so often as somebody else) were Bob Dickey (If you were a Princeton person, you knew Bob Dickey) and his laboratory co-mate called Robert Baringer (he became a professor at Yale after the war). We were very close friends for many years there. Those are the two I usually went to pick up to go to lunch together with, walking up to Central Square.

Pavlish:

The restaurant is not still there, is it?

Pound:

No. It was called M&M, MM something or other. [laughs] They made their own wonderful molasses bread. I used to buy a loaf to take home. My wife loved it too. Usually the waitress would give us the thing we wanted under the special of the day, even if it was not the special.

Pavlish:

Was the conversation during these regular lunches usually on physics topics? One of the interesting things is how you describe that you talked about the possibility of detecting something like NMR. I was wondering, was it serendipitous that this one time it turned into something big? Were there many different ideas being thrown about and then 1% of the ideas actually turned into productive work?

Pound:

Well, I suppose you could put it that way. I do not know, because we did not think of it at the time as being something leading to productive work. We were all of course concerned with the fact that we were going to be out of there [The MIT Radiation Lab] in fairly short order. Therefore, there was an issue as to, “What can we do next?” Our program there at the MIT Radiation Lab was pretty much determined by what it was committed to achieve. Whereas, at the end of the war we were going to be back in academia; although I had never been a professional in academia before that, because I went into all that Radiation Lab work straight out of being an undergraduate in college. I had been a senior in Physics at the University of Buffalo. One of my mentors there was Howard Schultz, who was my brother-in-law later. He married my younger sister — not younger than I, but the younger of the two sisters. He became a professor at Yale later. Howard and all these people, you see, were very well known to my family because my father was professor of Mathematical Physics. He had to teach, he had to have in his classes, all of the Physics majors at Buffalo.

Pavlish:

Did you take a class with your father?

Pound:

Oh yes. Not only that, but I had to take an oral exam with him. [laughs]

Pavlish:

Wow.

Pound:

Oh yes. He had all of the Physics majors. Quite a few of them became rather well-known in the world. There was a very distinguished physicist at Stanford named Chatterow [sp?]. He was one of my father’s students at Buffalo, before he went off to Stanford. Marvin Chatterow, I think his name was.

Pavlish:

Speaking of Stanford, one of the fascinating things about the discovery of NMR is that just a month after your publication of the discovery came Bloch and his group’s publication. In this article, you mention that Rabi might have visited them in December?

Pound:

He told them that we were up to this I think. So yes.

Pavlish:

Did Rabi visit you? Did he see what you were doing?

Pound:

Oh yes. Rabi was very much with us during all that time because we had been together for so much of the time during World War II. He was Ed Purcell’s immediate superior.

Pavlish:

At the Rad Lab?

Pound:

At the Rad Lab. See, Ed had become the chairman of the Department of Advanced Development. His predecessor in that had been Norman Ramsey. Norman Ramsey had been chairman of that department. But he quit and went off to found Brookhaven and so forth.

Pavlish:

So Rabi was with you at the Radiation Lab, but did he also stay on into the fall and into the winter of 1945 in Cambridge or did he go back to New York? Would he have visited ‘the shed’ for example, where you made the discovery of NMR?

Pound:

He might have, yes. He might have, being Purcell’s supervisor at MIT. The other person that was so much involved with us was Gerald Zacharias.

Pavlish:

Okay. He was a collaborator of Rabi’s in the initial molecular beam experiments?

Pound:

He had come to MIT on a more or less permanent basis. He in fact was my immediate boss when I first came to The Radiation Lab. I was assigned to the new group just being started under Gerald Zacharias, because Gerald Zacharias had just come back from spending a leave of absence of over a year where he was learning about electronic technology at Bell Laboratories. He had been sort of farmed out to the Bell Laboratories and so he was regarded as one that had a much bigger leg up in that business than any of the rest of the people at the Radiation Lab. Bell Labs was where the action was in terms of electronics in those days.

Pavlish:

Would he have seen your NMR apparatus? Would he have given you comments about the electronics? Or, was it more like you saw him at MIT and perhaps told him about what you were doing?

Pound:

I think more like that, yes. Zach, who ended up as a professor at MIT, he kept pretty close track of what was going on. The other person that knew very much about what we were doing was Al Hill, A. G. Hill, Albert George Hill, who became vice president of MIT. I understood that he once said, was it he? No, it was Rabi. It was Rabi, who called my wife and asked that she should give me a kick in the pants to get me to do something that I was able to do. He knew that I could but thought I was not up to my potential. He thought that I could have done much more than I was doing.

Pavlish:

This was after the Rad Lab, or when was this?

Pound:

It was after, yes.

Pavlish:

When you were actually working on the NMR?

Pound:

Yes.

Pavlish:

Before the publication of the first paper?

Pound:

I do not think so, no.

Pavlish:

After the publication of the first paper, once it was out in the community?

Pound:

Oh, that was just a letter that was not very revealing. The first paper that was very complete, much more complete than that, was what is called BPP.

Pavlish:

Right.

Pound:

That paper still did not really get into all the details. I think that in a way, the article that you found in that encyclopedia is as complete as any of the papers of that era. There was an annual volume called Annals of Nuclear Physics that I wrote a rather extended article for. That covered a lot of the issues like fluctuation narrowing and all the things we had learned about how to understand NMR in those days. I wrote that for a man named Frisch.

Pavlish:

At Cambridge?

Pound:

Yes, at Cambridge.

Pavlish:

The nephew of, he was the nephew of…

Pound:

Oh, of Lise Meitner. [laughs] Did you know that? He was very proud of Lise Meitner. In fact when I visited him there in Cambridge in 1948, the summer of ‘48, he had Lise Meitner there with him. I met her, then. She is the one that got so shortchanged by her colleagues in Munich.

Pavlish:

By Hahn.

Pound:

She was so instrumental in understanding nuclear fission. [laughs] I will always remember having Frisch over at our house in Arlington. He played the piano. Although my wife was not that impressed with his piano [playing] because she played the piano as well. The other person that brought him, who came with him, was Viktor Weisskopf; they were very close friends. Viki played piano too and thought he was good. Betty says that she thought that she could do that much better. And she could.

Pavlish:

She was quite a musician.

Pound:

Yes. We had acquired this beautiful 5 foot 6 inch small Steinway piano, which is set up in our house in a corner especially designed to accommodate it, in the living room. I will always remember Frisch going over there to play.

Pavlish:

Was Frisch working at the Rad Lab? Did he visit after World War II?

Pound:

I didn’t ever see him at Radiation Lab, no. I met him in my visit to the Cavendish, I imagine.

Pavlish:

Oh, and you said that was in 1948.

Pound:

Then, he talked me into writing a chapter for the book he was editing.

Pavlish:

Did you often have other physicists over to your place, for evening get-togethers? Can you remember, was there ever a time when you, Purcell, and Torrey, and your families were relaxing on a Saturday evening?

Pound:

No, the persons we were most likely to have over were the Van Vlecks. John H. Van Vleck was such a dear friend of ours. Van Vleck was a member of the Harvard Physics department. He was very friendly with people like Frisch, I think.

Pavlish:

What were the personalities like of those involved in the discovery of NMR? Would you say that you had complementary personalities? Did you focus on one aspect of the machine while Purcell and Torrey worked on other parts, in the beginning? From your article, it sounds like during the day you wrote the documents for The Rad Lab during the day and work on this NMR research in the evenings. Is that indeed how it went?

Pound:

Yes, except that I think that people looked at me as being such an expert in electronics — I sometimes resented it to a certain extent. George Pake (do you know the name? He just died a while ago come to think of it). I was very grateful to him once, because he wrote me a long letter to tell me how much he appreciated me as a physicist, and not as an electronics expert. That is something that I have always been grateful to him for, for making that point. I wished he had made it in a number of places. In the world at large and even particularly Purcell used to tell people that I was their electronics expert. That failed to recognize what I felt that I had contributed to this; in the sense of having been as fully conversant with the physics there as anyone else. Yet they looked at me as just a kid who had just got out of college. At The Radiation Lab there were generational issues. Almost all the people there were people who had finished PhDs somewhere or other. And here, I was just a kid out of The University of Buffalo, which was not your frontline research university; except it was more than people recognized. I can point out that my own father was the mainstay of the theoretical aspect of things there. He was a PhD physicist from The University of Toronto from 1912, which was long before anybody from this country was really that much into physics. Toronto was in the Cavendish orbit, you see. They looked to the Phil. Mag., which is where they published. Do you know what the Phil. Mag is? The Philosophical Magazine. That’s where all their publications were back in those days. I have found bound copies of my father’s thesis in Widener library, along the shelf where they have things from Rutherford and other people of that vintage. My father was one of the earliest people studying nuclear physics, radioactivity, at Toronto. His mentor is just getting a certain amount of attention and celebration in Toronto. He is called Sir John C. McKlennan [spelling?]. They are just making a thing about remembering his name. I got a little bit annoyed when the American Physical Society had a meeting in Canada, wherein they were supposedly reviewing the development of physics in Canada. They described McKlennan, not wrongly in a sense, because what McKlennan did was to put Canada into Low-Temperature Physics. He built a helium liquefier following the pattern of the Leyden designer of the helium liquefier. So Toronto was the only laboratory in North America in the low-temperature business. That was long after my father had done his work there.

Pavlish:

They had done radioactivity before that?

Pound:

That is right. That is what I am bringing up. They completely ignored that aspect of McKlennan who was one of the leaders in radioactivity. They thought of themselves as being parallel to Rutherford. Rutherford was at McGill at the time. Toronto and McGill were sort of at the same level in science there in Canada. Of course, most people would think Canada would not even count in those days. It is interesting to know that this thing that they wrote up in this meeting of the American Physical Society was the development of physics in Canada. I thought that they were being extremely ignorant in not recognizing how much had been done. There was no mention of McKlennan and the radioactivity work there. And nobody was doing that in this country. There was Hall, I think, at Harvard studying radioactivity to some extent. It is interesting that at lunches here I spend quite a lot of time with a woman called Rachel Hall. She is a niece or something of Edwin H. Hall, who was a professor at Harvard back in those days when I first came here.

Pavlish:

Have there been other physicists in your family, other scientists aside from yourself and your father?

Pound:

Not really. My mother’s father was an educator but not a scientist as such. His name was Mark Krouk [spelling?]. He died when I was four years old. That is the first and only funeral I have gone to. I was taken to it when I was four years old. It was my first and only railroad trip until I was into my middle twenties. That was a trip from Bridgeway, Ontario, to Toronto. He did not live in Toronto. He lived in Bowlinville [spelling?] Ontario. But my mother grew up in Toronto. And my father went to The University of Toronto as perhaps you are aware. His was the fourth PhD in physics at Toronto, in 1912.

Pavlish:

Is that your first memory, the railroad trip to Toronto?

Pound:

Yes, probably. It is an early memory.

Pavlish:

Four years old, that is very young.

Pound:

I remember it because there were special arrangements made for my two older sisters to stay behind. This issue has arisen recently. My father’s mother was named Frances Ellsworth. She died when she was 24 of consumption, what they called tuberculosis in those days. She was apparently a very beautiful woman and she was also an artist. We have in the house, still, sketches, paintings, and watercolors that she made when she was young. We also have four diaries that she wrote. She wrote two diaries in the years when my grandfather, called Isaac L. Pound, dragged her out to North Dakota. You could get a claim, as they called it. The United States was encouraging homesteaders to make claims, with The Homestead Act. They established a claim in North Dakota. That is when she came down with a severe case of consumption. She died when my father was four years old. We have pictures of her in the house. She was quite a beautiful young lady. One of the diaries she wrote while she was 17 years old, living in Ridgeway [sp?], Ontario. That is where I was born. She describes going to Weland. Weland is the biggest town in that part of Ontario. It is near Niagara Falls and St. Catherines. The Weland Canal is named for it. So, she went to Weland one day and in her diary she describes how she loves the city and hates the country [laughs]. Weland was hardly a big city. My wife and I always felt sad reading this stuff about her being dragged out to North Dakota, knowing how she felt about that. She did it, though. I do not think Weland exists anymore. It is part of the metropolitan district of Port Erie, as I recall. It was Weland County. In fact, my birth certificate is from Weland County.

Pavlish:

Getting back to your description of the discovery of Nuclear Magnetic Resonance, you give exact dates; I was a little confused by one of the references. You write, “Finally we were able to make a determined search for the resonance on the evening of Thursday, December 13th, 1945. Ed had brought in some home canners paraffin wax from a small grocery shop. We melted a couple of pounds and poured the cavity full.” This is almost trivial to ask, but was the grocery shop nearby? The shed where you did the experiment was adjacent to Jefferson Lab, right? The shed where Nuclear Magnetic Resonance was set up?

Pound:

That is where the magnet was, yes. J. C. Curry Street’s magnet that we used was in that building, on the back of room 432 or something like that.

Pavlish:

When he stopped by to buy the paraffin, would that have been a grocery shop in Harvard Square?

Pound:

No, it was on Massachusetts Avenue, a block or so above the corner of Martin Street and Mass. Avenue. It is still there. I have seen it. It is a general provisioner. It is more like a convenience store, not just a big grocery store. Ed was proud that he could stop there, pick that up, and bring it in with him that night; although I could have brought one in from home because I know we had some cans of paraffin at home.

Pavlish:

How had you decided on paraffin as the first sample?

Pound:

Because of two reasons; one is that paraffin is rich in protons. That was the main component. We knew that we could use protons because they had the biggest nuclear magnetic moment. That was well-known. The other thing that has a comparably big nuclear magnetic moment is fluorine, but fluorine does not come so simply.

Pavlish:

Do you remember whose idea it was to use paraffin?

Pound:

Oh, it was automatic for us, and there were two reasons. One is not only that it had all those protons; the other is because we were much involved in microwave spectroscopy, so we knew that paraffin had about the lowest electromagnetic absorption by ordinary dielectric laws, of anything going, you see. Paraffin was an extremely good dielectric, as we call it.

Pavlish:

That was from your work at The Rad Lab, that you had been looking at absorption of microwaves?

Pound:

Yes. Purcell, Torrey, and I all knew paraffin. Torrey was particularly knowledgeable in that field because he was in charge of the study of semi-conducting crystals. He had come from Columbia University, where they had done a lot of work in electromagnetic absorption and so forth, too.

Pavlish:

Before the War?

Pound:

Well, before coming to The Radiation Lab.

Pavlish:

As a scientific problem as opposed to a practical problem?

Pound:

Yes, that is right.

Pavlish:

You open this article by writing, that “Academic scientific research, especially in physics, was almost completely suspended between 1940 and 1945.” You go on in that paragraph to describe the work at The Radiation Lab. How much did the work there hinder the progress of physics and how much did it help the progress of physics?

Pound:

Purcell often pointed out that we were not doing physics; we were engineers. We felt that what we were doing was really a form of electromagnetic engineering. More so than had been the case with Rabi’s group at Columbia where they were very proud of being physicists. I got kind of criticized sometimes for not concentrating on physics, I guess, as compared with being an electronics guru. But, you see, my electronics background sprung from my 10-12 year old’s start in amateur radio.

Pavlish:

Really?

Pound:

Oh, yes.

Pavlish:

Is that how you got into physics?

Pound:

That is how I got into, not physics so much, as how I got into science, yes. I think I would have gotten into physics through my family background in the first place. Although, I do resist saying that. Do you know about Phyllis Geller (what was her name?)? She worked for Razowski [sp?] as the Dean. She published a book, and at one stage I was kind of offended by it because in that book she described me as somebody who had just followed in his father’s footsteps and his background in engineering, which was kind of a put-down. I complained about it and she fixed it. [laughs] That is part of the game I was mentioning, that they were putting me down as a sort of engineering type who did the electronics and nothing else. I got her off of that. I think she is at Brandeis now. She was the principal advisor and assistant to Henry Rezowski [sp?] while he was Dean of Harvard. I had a little bit of a snarl with him. That is because I made speeches against the core curriculum. I got well-recognized among the faculty as being the main anti-core-curriculum spokesman. It was Henry’s invention. I know he gave a speech that claimed that it bothered him that I would be against it, because I was not only a good physicists, but a good physicist. Which reminds me of something else. A good friend of mine was Alfred North Whitehead. You may know the name. He was a member of The Harvard Society of Fellows. I used to drive him to dinners and various things. They claim, and I cannot quite believe it, it does not seem proper, that when The University was debating about appointing James Bryan Conant as president, the story I have been hearing, lately, is that Whitehead said that, “Conant is a chemist. It would not be suitable to have a chemist as president of Harvard University.” [laughs] The comeback to it was, “But look, Charles Eliot was a chemist.” [laughs] He was of course one of the longest term presidents of Harvard. He was highly respected. He introduced the electives system and all that. It is reputed that Whitehead said that, “Yes, but Conant is a good chemist.” [laughs]

Pavlish:

That is a good story. Getting back to this excellent description of yours, starting on Thursday, December 13th. You mention how Purcell picked up the paraffin at a grocery shop. You write, “We balanced our bridge down to receiver noise, increased the input power and rebalanced, until we could no longer reduce the meter reading to that of pure receiver noise.” It goes on. I am trying to picture it in my head. Is it you and Torrey leaning over the apparatus? Is Purcell in the room?

Pound:

We were all three there, but I am the one that was the guru of this kind of thing. Neither of them would have been handling it in that way. I always remember that what we call noise there, some of that noise is simply the residual power-line hum that is always in the background of the power supply. There is a certain amount of residual hum left over. When you amplify things like that, it gets to the point that you cannot get it down any further. We cannot balance it because there is no other side to it. A lot of people, who have not been involved in that kind of thing, would not really appreciate that kind of statement. That is why I put it in. I am amused that I have a recent letter from some dear friends of mine. One of them is John Hall. Does the name mean anything to you? He just got the Nobel Prize. John Hall, and another person, Ronald Dreever. Ronald Dreever worked with me. He is a Scotsman. He works on this LIGO project [gravity wave experiment]. He has been dedicated to gravity wave experiments. He comes to see us. He is a dear. He and John Hall wrote me a postcard from Switzerland where they were together. They described me as having educated them. They said, “We are two of your disciples who picked up the frequency locking technique that you invented.” It was so sweet of them to make that point because they are among the only people in the world that recognize my role in that. Frequency locking meant that you could control the frequency of something from another signal by injecting one of the signals into the other device. If you knew what you were doing, you could do it so that one of them would be exactly in phase. There would be no slipping.

Pavlish:

When did you invent that?

Pound:

What they are speaking of is when they would have been together, which would have been in the 1960s, I think.

Pavlish:

Was this in relation to your work in NMR?

Pound:

No. It was quite a long time afterwards. I had spent a year at Boulder. That is where John Hall is. I had taken a sabbatical year and spent it at Boulder, Colorado. That is where I educated John Hall in that respect. He was the right person because he thought the same way I did in this connection. There are not too many out there that did.

Pavlish:

In your article here you say, “We watched the meter for evidence of a change in balance as we passed back and forth through the region of 73 Amps, of magnet current.” When I read this, I see somebody twitching the nob. Would that have been you? Did you take turns? If you were to describe this discovery to somebody who does not even know what an Amp is exactly, how would you characterize it? Obviously, it is too long ago to know what color shirt you were wearing?

Pound:

Well, among other things, I would follow on something that Purcell once mentioned, that we should not describe it as a discovery; he was not speaking about this particularly; as he pointed out, it was something entirely predictable, and if it had not been the way it is, if it had not worked, it would have been completely our fault because everything about it was calculable.

Pavlish:

You had calculated it beforehand, so you expected it to work?

Pound:

Oh, yes.

Pavlish:

That is why you do not regard it so much as a discovery. You did not say, “Oh, what is this?” You were looking for the effect.

Pound:

That is right. All we did was dig it out of the noise. It was just as it should be. Sure enough it was there. And if it were not, as Ed once said, it would have been bad, because we would not have known anything.

Pavlish:

Here you write, in the article, “At about 4 am on Friday morning, somewhat discouraged, we shut down, with the agreement to try again on Saturday.” I am thinking, 4 am, that is very late into the night!

Pound:

Oh, well, we used to do that kind of thing — work all night. We not only did that in that case, but we were quite used to it during the war years, in the Radiation Lab, oh yes. I think we put in longer hours than anybody ever realized in The MIT Radiation Lab days, just before any of this came up. So we were quite, what is the word, immune to any concern about those kinds of hours.

Pavlish:

If you were working on reports during the day, what time would you have started lab work?

Pound:

I do not know what working on reports means, because I do not think we did anything but write a Letter to the Editor in The Physical Review.

Pavlish:

Oh no, I mean the reports about the work that you had done in The Radiation Lab.

Pound:

Oh, that is not reports. Those were the books! I was working on those day and night, pretty much, mostly at home. Ed said he would do his writing on Saturday morning.

Pavlish:

Was 4 am on the date of Friday, the 14th, or on the 15th?

Pound:

I bring in the fact of the 13th, don’t I? That is because I had a record on that, because that is the day there was a snowstorm in Boston. I checked that out and found there had been about a 6-inch snowstorm. That is why I chose that day to cite as the day we tried but failed. I think I say that, don’t I, that I had driven Purcell and Torrey to Harvard that day?

Pavlish:

It is not mentioned in here.

Pound:

Oh. Because that is what we did. We got together in order to be together when we tried the thing out, but we did not detect anything when we started. I do not know if I mentioned it there, but I know I did one time when I was writing, was that in my mind was this New Yorker story about a friend of mine who was the head of The Department of Physics at Columbia, described having gone to a meeting, where Niels Bohr described the discovery of nuclear fission. And he describes in his article, how he went home to Columbia after that meeting, and thought heavily about it, because he went off, leaning into the snow which was coming down, leaning against the wind and the snow. So, on the 13th, I said to myself, we can lean into the rain if necessary, and contemplate what we had just done.

Pavlish:

What was the atmosphere like in the lab once you got the signal? You had made the calculation, so you expected to see it. Was there a feeling of elation, of accomplishment? Did you call other people into the lab?

Pound:

No, we just took it for granted. As Ed has sometimes said, if we had not been able to find it, that would have been catastrophe, because everything was clearly calculable, and there is no way it could have failed. Now the only way it could have failed was by what is called saturation; overpowered by the RF field, so the absorption can be wiped out by being saturated. We knew enough about it; we kept it at a level so that it could not do that. So, we knew what we were doing that way. There was no danger of losing, from that point of view. I think, some people who have not been through that kind of thing, would not have realized, how much we really knew and had the quantitative ideas about how to deal with it; avoiding saturation and keeping the RF level down where it would not override the interactions in the material and so forth. We were pretty clear about what we were doing.

Pavlish:

In this article you mention that you think of Nuclear Magnetic Resonance as part of Nuclear Physics.

Pound:

That is what I thought in the beginning.

Pavlish:

When did it become clear that NMR would be applicable to many different parts of science?

Pound:

Well, we discovered that quantitative aspects to study were things like the relaxation times, and the line widths, and all those things which were not so much nuclear properties as properties of Materials Science. And so, the whole thing immediately turned into Chemistry and Materials Science, Physical Chemistry. And of course, the physical chemists took the whole field over in the long run. I have sometimes mentioned that several of the things I have gotten involved in, turned into Chemistry pretty quickly; another one being the study of nuclear transitions.

Pavlish:

How about the ‘Pound Box’?

Pound:

What about it? When Paul Horowitz first came, he introduced me for a lecture at Harvard. He described how when he was in prep school in New Jersey, he got sent to Columbia where they had a special program for advanced placement undergraduates. So, he got assigned to a graduate student, who put him onto a Pound box. He said that it was not until he came to Harvard that he discovered there was a Pound. He said, he had always thought the Pound box meant that in order to make it work, you had to pound it. [laughs] Anyway, that is Paul Horowitz for you.

Pavlish:

Aside from the initial development of NMR, how much of your career in physics was dedicated to magnetic resonance?

Pound:

Well, in those first years, I spent almost all of my time developing nuclear quadrupole interactions. I thought that was going to be a new and independent dimension of the whole subject, which it is to some extent. It has never gotten the recognition that I thought it might deserve. I was the first one to get into that area. When I started studying Nuclear Magnetic Resonance in crystals, and in solids and so forth, I began studying line-shapes and structures. I soon realized that the Nuclear Quadrupole Moment could be exploited. Not only that, but the energy gaps that were introduced by the interactions of nuclei through the quadrupole moment with the electric fields in materials were much bigger than you could produce with magnets on the magnetic moments. I always used to get a little bit annoyed when people spoke about all these other things in terms of their magnetic moments. They do not work that way, because their interactions in materials with quadrupole interactions completely dominates their behavior. You cannot isolate that from the magnetic moment aspect. The magnetic moment aspect is trivial compared with the electric quadrupole effect.

Pavlish:

Did your father witness your great successes in your early days at Harvard?

Pound:

To some extent. I would say he was aware, and relatively proud of the fact that I made some headway like that. Of course, my two sisters had some credibility too. My sister Jill [sp?] was a mathematician. She became a school teacher in mathematics. She taught mathematics at Wellesley High School for some time. My other sister however, is basically an artist. She married Howard Schultz, who was a professor at Yale.

Pavlish:

The physicist who studied under your father?

Pound:

Yes. Jill’s husband, Harold Hart, also had studied under my father. He is now Vice-President at Raytheon. When I came to Boston, the purpose was to work with him. He was the head of the radar program which was just starting, at a company called The Submarine Signal Company.