Oral History Transcript — Dr. Peter Van de Kamp
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Peter Van de Kamp; April 9, 1977
ABSTRACT: Recollections of family background and early schooling in Holland; interest in science and influence of C. Flammarionís writings; university training at Utrecht; contact with Julius and brief interlude on Einstein; astronomy at Utrecht and practical work with van der Bildt; move to Groningen and work with P.J. van Rhijn; contact with E. Hertzsprung; move to Virginia and association with S.A. Mitchell and H. Alden; decision to remain in America; contact with Vyssotsky; Ph.D. exam at Lick Observatory; life at Lick; organization of science in the Netherlands -- Kapteynís legacy; research on interstellar absorption circa 1930 and contact with R. Trumpler; peer review in professional journals; collaboration with Vyssotsky and work on galactic structure and interstellar medium; double star work, 1931, Barnardís star origin of interest; religion and philosophy.
Session I | Session II
DeVorkin:I know you were born in Kampen. I believe it was 1901. But I donít know anything else about your family, and to start off the Oral History, who were your parents? What did they do? A little background on your family.
Van de Kamp:My father was Lubbertus van de Kamp, and he was born in Ijsselmuiden which is a small village near Kampen, across the Ijssel River, in 1872. He did not have the benefit of an education, after primary school. Thatís the way it was in those days in the country. So he went to work early, at a clerical position, and later on, had an administrative position at a business firm; Kampen had a strong cigar making industry. So he became very much a self-educated man. He learned foreign languages and all kinds of other things which are taken for granted now, in Holland at least. Mother was born in Alkmaar. Her name is Eugelina Cornelia Adriana van der Wal. She was born in 1875. They married in 1901, in March. I was one of the first results of their marriage, December 26th, the day after Christmas. Mother had regular education in Alkmaar, later Amsterdam, where we frequently went as children because Grandmother lived there. Besides myself there was my younger brother, Jacob, who was 2Ĺ years younger and who also came to the United States later. I came in 1923. He came in 1929, as a research chemist. If you like you can get more information about that.
DeVorkin:Did your father continue working in the cigar industry during your childhood?
Van de Kamp:Yes. In those days, certainly in Holland, one did not move very easily from one profession to another. Remember that we are talking now about the days before World War I, the ďgood old days,Ē when people like my father were exploited by the system. I say that advisedly. Thatís the way it was. He had one weekís vacation in the year. He had the terrific salary of $400 a year — a year! And no wonder that my mother, a very forceful woman, was a strong supporter of the Socialist movement in Holland, so as to bring about better working conditions, for my father, and for others, of course.
DeVorkin:How did your father feel about this?
Van de Kamp:Oh, the same way, of course. He was caught in the system. He was not a revolutionary or an activist or anything like that. One didnít do that so easily in those days. He went to work at 7 in the morning, had a lunch break from 12 to 1:30 — that was a holy thing even for the workman in Holland — and then came home at 6 or 7 in the evening. And it was a big event in our lives when the government finally decreed that Saturday afternoons should be free. It was the first accomplishment of the equivalent of the labor movement in Holland. A free Saturday afternoon! Can you imagine? What a thrill it was!
DeVorkin:What did you and your family do on these free Saturday afternoons together?
Van de Kamp:Well, it probably rained, since this was in Holland. Of course, home life was very strong. I donít recall what we did on Saturday afternoons. I remember the ritual on Sunday was to visit Grandfather, who lived in Ijsselmuiden where my father was born. My Grandfather had several sons and daughters. As a matter of fact, the last year when I was in Holland, I visited two of my cousins, who are in their eighties now and are still doing well, thank you. I have pictures of them somewhere. But Sunday morning, we walked. That was the mode of transportation. We walked a mile or so to visit Grandfather and pay respects. Grandfather was a nice, lively gentleman. So, I remember very strongly that we didnít mind particularly, because Grandfather was nice, and we probably got a cookie or so, and we could play in the garden and eat berries, red currants and gooseberries, whatever there was. We probably were not supposed to, but we did anyway.
DeVorkin:What did you grandfather do during his life?
Van de Kamp:Grandfather had a laundry. A big laundry with machinery and all that. He served a wider neighborhood. If you look at old maps of Holland, of Kampen, (I have one upstairs) even 300 years ago, in that particular section, you see shirts and things lying on the grass, drying in the sunshine. So that thereís a long tradition there of laundry.
DeVorkin:And this was in the family.
Van de Kamp:In the family, yes. My father broke away from that, he became a clerical man, a bookkeeper, an administrator. Father was a highly intelligent man, a very gifted man. As I said before, he learned foreign languages, and read and read and read. Both Father and Mother decided that the children should be given the benefit of all possible education. Mother was the prime mover toward our continued education and scholarly careers. This was in a sense a reaction to my Father not having had it. So all three boys, I and later Jacob and then still later Jan, the younger brother, all went to the university. And Iím glad to say, all did well afterwards. This was not easy for the parents, because in 1914, the First World War broke out, and this led to inflation and all kinds of things. I donít know the details about it, but I remember that before the First World War, even on fatherís munificent salary, $400 a year, we had a nice life. And we had a maid, of course. The maid was paid one guilder a week. That was the equivalent of forty American cents a week, which was all right. Some maids didnít like that. They went to The Hague in Holland because they could earn a dollar a week there. Well, of course, the dollar meant a little more than it does now!
DeVorkin:Your older brother, did he go to Utrecht, too?
Van de Kamp:I was the oldest one. Then Jacob was 2Ĺ years younger, which meant in school and in university, he was three years behind, the way it worked out. Yes, he also went to the University of Utrecht and studied chemistry there.
DeVorkin:Getting into your early schooling, before Utrecht. Could you describe your early schooling? You mentioned, your father read a lot. What kinds of books did he read and what kinds of books were you exposed to through your family?
Van de Kamp:Oh, I donít remember too clearly. I remember that long before we went to school, we knew how to read and write. I mention that because nowadays there are people the world over, also in the country, who never learn to read and write.
DeVorkin:What age did you go to school?
Van de Kamp:The year in which one became six years of age. I went to school at the age of five, since I was born before January 1.
DeVorkin:Was this the equivalent of what we would call public school?
Van de Kamp:
Public school, yes. But this was the grammar school then. In my days, I donít know how it is now, there were different types of grammar school. There was the regular grammar school for — letís name it the way it was — the middle class. And then there was also a grammar school for the proletariat, as I call it, for the working man, of which there were many in Kampen. And then there was a grammar school which was called School A, where one paid a few dollars a year, and you got better teaching there. It sounds all terribly undemocratic. In other words, there was a recognition of economic position, or rather willingness to pay. It smells like elitism. Iím all for elitism. I think itís very good. Iím glad I benefited from it. My parents scraped together their pennies and sent us to the best school, you see. Not a private school. What is called private school here or public school in England, I think, is in Holland mostly for problem people, rich problem people quite often.
They were sent to private schools. But in the small town where I was, everyone was together in the grammar school. I could show you a photograph, as a matter of fact, of the third grade, all these children with the teacher. There were the people from different classes of life, really, except come to think of it, there were no children of the laboring class. Iím speaking of grammar school now, primary grade. Beyond that, we got the secondary school, it was called high school, except that the high school in Holland included and still includes two years of college. In other words, we were two years ahead of here. I think that is still that way. Although Iím sure education in Holland has deteriorated, also, in the way it has everywhere, in the Western world. But nobody was required to go to high school. You also had to pay a certain amount. And that was definitely intended only for those whom the parents felt were worth educating. In other words, you didnít have to go to high school to make it in life later on. This was the system at that time. Why should the son of a cigar maker, as we called them, go to high school? He didnít belong there. In that respect, we, being middle class, lower middle class if you wish, felt that it was all right, you see, taken for granted. Of course, what basically counted was the attitude of the parents. I donít mean that the child of a cigar maker couldnít have gone to high school. Of course he could have. But it probably didnít occur to him that he should. He just became another cigar maker.
DeVorkin:Did your father or mother have any interest in science or in collecting? As you said, your father was a bookkeeper, a clerk. Did he have a mind which would lead to classification and order in his life, and therefore in the life of his family?
Van de Kamp:I may not give a direct answer to that. My father would have made an excellent teacher. As a matter of fact, I remember later on, when he was in his sixties, he visited in this country here, and he happened to visit a local school here. We were just showing him around, and as one of these coincidences, one of the school teachers, a woman — as a contrast with ďoldĒ Holland, where practically all the school teachers were men, except for the first two grades, we had women teachers and above that, naturally, men teachers — Well, anyway, we visited this school and the woman teacher came up to my wife, frantically, and said, ďOh, my gosh, our teacher is sick today, what shall we do? And we were just to talk on geography about Holland.Ē My wife said, ďHere is my father-in-law, Peterís father. Heís from Holland, just came from Holland. Let him talk to the children.Ē He did. He talked to the children about Holland. His English was quite good, and he did it very well. I think he was basically a teacher. Just as I am basically what I call a school master, and I use that word advisedly, I think itís a very fine profession. Of course, his other interest, besides reading in general, of all the foreign languages, English and England. He made a short visit to England one time, his only visit. England and English were his love. Then beside that, of course, music. That also rubbed off on me, because Iím also a musician, be it an amateur.
DeVorkin:Did you start your musical training quite young?
Van de Kamp:Well, I started — we had a piano at home, so naturally I started playing the piano, and father helped. I never had piano lessons, but itís something one can learn by oneself.
DeVorkin:How old were you?
Van de Kamp:Oh, at the age of six or seven or so. Then at the age of eight, a little later, I started violin, and I had violin lessons for eight or nine years. So formally speaking, thatís my instrument.
DeVorkin:Did your father start you out on anything scientific?
Van de Kamp:No.
DeVorkin:Where did that influence come from.
Van de Kamp:I think, that was rather from the teachers. It just happened. Well, I was a bright boy. OK. One can say that at my age. I was bright and I was number one. Itís quite interesting. I think it was in the third or fourth grade, for the first time, the students got serial numbers, after the first semester, letís say. And the 40 students — we didnít call them students, we called them pupils in those days — were arranged in order from one to the lowest. Very cruel somehow. I turned out to be Number 1. The lowest one was the son of one of the rich people in town, as a matter of fact the son of my fatherís boss! This I shall never forget, because it gave me the idea that the brighter people were from the poorer classes. I observed it frequently. And perhaps thatís the way it should be. The new blood comes from there.
DeVorkin:Thatís an interesting observation. Do you recall the teacher specifically?
Van de Kamp:Oh, very well, yes.
DeVorkin:What was his name?
Van de Kamp:Well, in grammar school we had six grades, and each grade had a separate teacher. As I said before, the first two grades we had women, Ju Frau Wolbers and Ju Frau Oelhof. I still remember. They had no particular influence, I think. They were just good. But the real inspiration came in high school, after the age of 11. In high school, we had several subjects. There were no choices. Everything was just the way it was. You took everything. If you couldnít make it, you just failed. You might try again for a year. And altogether — this even amazes me nowadays — when it came to the final examination, at the age of 16 or 17, we were examined in 17 subjects. 17 subjects!
DeVorkin:All at once?
Van de Kamp:Yes. We had them all at once. No foolishness about electives and all that. Of course, this was before the days of psychology and sociology, all these fuzzy subjects, you see. We had the three foreign languages. Then there was Dutch, the native language, of course, which was not neglected.
DeVorkin:Which were the three foreign languages?
Van de Kamp:The three foreign languages — French, German and English. Still every Dutch person who goes to high school learns French, German and English, I think. Not just one year, but several. I have a list of it, I can give it to you. Itís quite interesting. I kept it deliberately. Actually in my days, we started French in grammar school. That was still a hangover or leftover from the Napoleonic times. So we had French for 7Ĺ years. I started French very early, with the result that I have virtually no accent in French. I have an accent in English. I know it, a nice little Dutch accent. And I have an accent in German. We had German for five years, in high school, four hours a week. You may say, why? Because German is so close to Dutch. Well, thatís exactly why. To keep them apart. We had English for only four years. English is really a simple language. It has little grammar, so to speak. I mean, up to a point. I know itís a very rich language, and is probably the language I know best, although itís a tossup between English and Dutch at this stage. So that continued, and as I say, every year, for three, four hours a week, we had these languages. The classical equivalent of high school which was called gymnasium, in addition to the three foreign languages you also learned Latin and Greek, and Hebrew was optional. So some people learned seven languages at once. It can be done, you see. Itís just a matter of tradition of the country.
DeVorkin:Did you elect the Hebrew, by any chance?
Van de Kamp:No, that was for the classical. I elected, for better or worse, I made a choice, when it came to secondary school, to take the scientific aspect, where there was more stress on mathematics and physics. And that means I never had any formal training or education in Latin or Greek, which I think is regrettable, in a way. But itís too late now.
DeVorkin:Well, could we talk about your scientific training then?
Van de Kamp:In the scientific training, I had good luck in high school. I have a good perspective now of 60 years. I had two first rate teachers, one in mathematics who was absolutely superb, and the other in chemistry, of all things. The physics teacher was ordinary. He was not that good. But the math teacher was absolutely superb.
DeVorkin:What were their names?
Van de Kamp:The mathematics teacher was J. Van de Griend, there were no female teachers in high school. This was high school. The chemistry teacher also was superb, M.J. van der Stadt, and meant a great deal to my brother, who went to do chemistry later. But thereís no doubt about it (as I look back upon it), that these two people, especially the math teacher, helped a great deal to awaken or form my interests. And then when the time came to graduate from high school, well, it was obvious that I would go into what was called, and is still called, higher learning, the university.
DeVorkin:Were you pretty sure by high school or before then that you were going to college?
Van de Kamp:Oh, before. My parents had made up their minds that we were going to the university later on. I was very good at mathematics, and there was a trial or a difficult period because I had become very much interested in music. And besides playing at the piano and playing the violin, at the age of 14 I started composing and I had a little orchestra and all that, and I thought I should become a professional musician.
DeVorkin:But by this time you had no formal training. You said you took eight years of violin?
Van de Kamp:Yes.
Van de Kamp:No, not piano.
DeVorkin:But you did have training in violin.
Van de Kamp:Yes. But I thought I would become a musician, in a very vague way, compose and be a conductor of a big orchestra and all that. Well, I have been a conductor of several little orchestras in my life. But good well meaning friends advised me that I should not go into music.
DeVorkin:What was their reason?
Van de Kamp:Well, I think they were very wise. They realized that to be a professional in music, you have to be awfully good, and they knew I was good in mathematics and that sort of thing. Actually my father took me to the Conservatory in Amsterdam at one time, to have an interview with the director there, and I was not encouraged, really, by them that I should do this.
DeVorkin:Did the lure of science and mathematics help you decide?
Van de Kamp:Oh, in favor of science and mathematics. Then it became a choice, really. I could have become a mathematician very easily. I think that would have been easy. Physics did not attract me particularly; chemistry, more. But then I became interested in astronomy.
DeVorkin:How did that come about?
Van de Kamp:Well, partly, but not entirely — astronomy was taught in high school in those days, cosmography.
DeVorkin:And you did take this?
Van de Kamp:Yes, of course, I have to (no electives) but this was not particularly interesting.
DeVorkin:Do you recall your teacher? Was it the physics teacher?
Van de Kamp:No, it was a math teacher who also taught cosmography.
DeVorkin:The same math teacher who was very stimulating?
Van de Kamp:No, this was another one. Another math teacher especially for algebra. The stimulating one was for what we called arithmetic and geometry.
DeVorkin:Did you have trigonometry at that time?
Van de Kamp:Oh, yes, we had trigonometry. We had plane geometry and we had solid geometry in high school. Excuse me if I look through my books. What is that book? There was a teacher of mathematics in the gymnasium who retired and decided to sell his books, and I bought this book for ten Dutch cents.
DeVorkin:What is the name of this book?
Van de Kamp:HEMEL EN TARDE (SKY AND EARTH).
DeVorkin:Oh, Flammarionís book.
Van de Kamp:And this was translated into Dutch by a gentleman by the name of Goudsmit, and hereís a picture of the observatory at Leyden. Now, I notice that I gave this book obviously to my brother, because his signature is in it. It was mine originally.
DeVorkin:Is this one of the first books that you read in astronomy?
Van de Kamp:Yes. I got it in February, 1917, and I read and became quite fascinated by this. There were some lousy pictures of the constellations in here, very bad! That was in 1917, while I was in, I think, what we called tenth grade, in high school. And this drew me very much to astronomy. So then in 1918, I decided that, since I had given up the idea of becoming a musician, I was going to be an astronomer.
DeVorkin:And you can actually direct it to reading this book?
Van de Kamp:I think, very much so, yes. As a matter of fact, I told Madame Flammarion this. I knew her. As a matter of fact, I gave a lecture, for the Societe Astronomique de France on December 11th, 1949, and I paid my respects to the memory of Camille Flammarion, for having gotten me started in astronomy. Iím not saying that I have gotten started in astronomy anyway, but this helped very much.
DeVorkin:I notice that thereís a scene of Leyden on the title page.
Van de Kamp:In the Dutch edition, yes. It was not in the original French edition. The other pictures are all from the French edition.
DeVorkin:All right, then — this was 1917, and youíve identified that as approximately the time that you became interested in astronomy. Through this book or through your teacher, did you see the relationship of astronomy to physics and to mathematics? At that time?
Van de Kamp:Not so much to physics. I think astronomy was a lot more mathematical than physical in those days. Iím not even sure that the word ďastrophysicsĒ existed.
Van de Kamp:Yes. Well, that. The astronomy which we learned in high school, as I said, was called cosmography, and it was terribly dull. It dealt with right ascension, declination, sidereal time, azimuth, equation of time — and then finally as a last chapter, something about the universe. But it was really basically what on a university level would be called spherical astronomy. A very reputable subject, I know, but not inspiring for a youngster.
DeVorkin:Did you have a text for this?
Van de Kamp:Now youíve got me there. Yes, we had a text book. Just a little book, a Dutch book, and I donít know at this moment what the textbook was. I donít think I kept it. It was quite uninteresting.
DeVorkin:All right. But it was Flammarion and his descriptive writingsÖ
Van de Kamp:— Yes, that really gave me a push. Thereís no doubt about that.
DeVorkin:Do you recall any of the particular elements in the book that did?
Van de Kamp:No. I remember, after having got this book, after Iíd gotten the book, looking at these very poor star maps, that for the first time that year, I saw the new constellations come — the first time that I had seen the constellations in the sky. I became fascinated with them, really. I was a teenager, 14, 15, and — well, one is romantic in that respect, and this was just beautiful. I didnít think in terms of distances, but simply the revelation that, of the constellations. But at the same time, of course, mathematics always came very easy to me. I enjoyed the beauty of mathematics. I almost was going to say, the uselessness of it, the same way that music is useless. Itís beautiful. Well, you know what I mean. You can do a lot of harm with music and with mathematics, of course.
DeVorkin:Something that makes you feel good isnít useless.
Van de Kamp:The best things in life are the useless things!
DeVorkin:When you became interested, then, in the year 1917 approximately, as you place it, this was a year before you were to go to college.
Van de Kamp:Yes, to the university. ďCollegeĒ didnít exist, you see.
DeVorkin:Did you make your feelings known to your father, that there might be a specialization in science, at this time?
Van de Kamp:Oh, yes. Now that of course was not too serious a matter, because whether you were going to specialize in mathematics, physics or astronomy, you got the same first two years. I think thatís still the way it is everywhere. So my diploma, which I have somewhere, reads that I have received my diploma, the Candidaat — what is called the Bachelorís degree here. When you enter the university in Holland you already have half the bachelorís degree. Itís like having had junior college already, the equivalent of the Dutch high school diploma. So this is the Candidaat degree.
DeVorkin:That was in 1920 you received that.
Van de Kamp:I received that in 1920, yes. And that included mathematics, physics and astronomy.
DeVorkin:OK, youíve gotten out a sheaf of papers from your file that have some very fascinating pictures in them, and you have your diploma, is that correct?
Van de Kamp:Yes. This is the end of high school. We had these 17 subjects.
DeVorkin:I see, and these are the grades?
Van de Kamp:Thatís mathematics. I was best at mathematics and mechanics. And I still am, I think. Physics, chemistry, biology, cosmography, political science, economics, geography, history, bookkeeping — we had two years of bookkeeping — Dutch, French, English, German, drawing and drafting.
DeVorkin:These were your records of completion.
Van de Kamp:Here is the Candidaat diploma in mathematics, physics. A candidate for mathematics, physics, astronomy chemistry. Cum laude, bin! This was the 5th of July, 1920. This was my second degree, doctoramdus, yes. (Showing the diploma)
DeVorkin:Letís talk about Utrecht. How did you come to go to the university?
Van de Kamp:Well, the explanation is really very simple. I had an uncle and aunt who lived in Utrecht. And I could not have afforded to go to any other university. But they were understanding and I was able to live with them, for a nominal monthly price of 30 guilders. Leiden, of course, would have been as good or better. All universities in Holland were good. There were few of them, and theyíre all good. So, Leiden of course was more interesting, in a way, thereís no doubt about that.
DeVorkin:Were you interested specifically in astronomical training, at this time?
Van de Kamp:I wanted to study astronomy, and I could have done it in Leiden, Utrecht, or Gronigen or Amsterdam. But I went to Utrecht because I could live, there with my uncle and aunt. Otherwise my parents could not have afforded it. This was 1918, remember. I went there a few months before the Armistice, and my parents were properly poor. We were very poor. Thatís it. No reserves of any kind.
DeVorkin:There was nothing through the war that ever made you fear that you would not be able to go to the university?
Van de Kamp:No. The enthusiasm remained. We took it for granted that thatís what we should do. Fortunately, from the economic point of view, as soon as I became a student at Utrecht, I was able to support myself by tutoring, because there were always lots of students, and others, but mostly students, who needed tutoring badly, and I was very well paid.
DeVorkin:What was the average kind of student at the university at that time, as far as background is concerned? And interests?
Van de Kamp:Well, I can judge only, of course, of the science students. They came from all levels. Certainly by that time, a good number came definitely from the middle class. When I think of the early days, many more may have come from the so-called higher, upper classes, but the upper classes wouldnít go to science in particular. Upper classes would go to law and that sort of thing.
DeVorkin:I see. Why is there that difference? How was science thought of in society?
Van de Kamp:Oh, Holland has always had a very high regard for science, I think, and a very high reputation in science.
DeVorkin:But the statement you made is quite interesting.
Van de Kamp:Itís a matter of class, I think. I must be careful, because I cannot prove any of this. Itís feelings more than anything else.
DeVorkin:But feelings are what weíre interested in. Your own feelings about the position of science in society would be very valuable for us.
Van de Kamp:For example, there was never any doubt in my mind, or in the minds of my fellow students, that we wouldnít get a position later on. There was not that terrible uncertainty that there is in this country now, where many people have their PhD in astronomy and they canít get a job. That sort of thing didnít exist in those days. Things were much better in balance, somehow. We knew that not every one of us would become a professor, because the number of professorships was extremely limited. You could predict that you would have to wait at least, say ten, years before he might die or retire, that sort of thing, you see. And professors stayed at the same place for a long time. There was not the mobility which exists here, or in Holland too now. The total astronomical population in Holland was very small in those days, just a few professors, and now it has increased at least tenfold.
DeVorkin:What was the social standing of a professor at the university compared to a lawyer or a doctor?
Van de Kamp:Well, I think very high. Professors were very high. There was not that stratification which we have here, and which I like, of professor, associate professor, assistant professor, instructor, and all that. In my life I went through the whole row. Assistant, associate, instructor, etc. I think this is good. In Holland, in Amsterdam, for example, where I know the situation very well, thereís one professor, P.J. van den Heuvel, a very good man. Heís a professor. And then thereís a lecturer, and there are — grades, we call it. The equivalent of some high civil servants, research situations.
DeVorkin:As a university student, how were you respected in the community?
Van de Kamp:Oh, the students. Utrecht was not exactly a village. Itís a fairly large town. The students were accepted at being part of the scenery.
DeVorkin:How did you feel as a student, part of the scenery?
Van de Kamp:Yes. Well, you felt very much part of the academic group, of course. Unconsciously we felt probably superior to the non-academic people. There was a bit of that feeling, without malice.
DeVorkin:During your first two years, you did have science, physics, mathematics. Did you have astronomy?
Van de Kamp:Yes. I took a general course in astronomy with Nijland. He was professor of astronomy. He was a specialist in visual observations of variable stars, a field that doesnít exist anymore. But he was very good at that, and he was a good teacher, no doubt about it. There was no personal contact whatsoever with the professor. I visited him once to pay my respects. I still remember, I left the visiting card I had in those days, you know, and when I left, he gave the card back to me. He said, ďYou can use it again.Ē That was very nice. Thatís the only thing I remember about that conversation.
DeVorkin:Whom did you have contact with?
Van de Kamp:Iíll come to that in a moment. There was Nijland, the astronomy professor, and then there was W.J.H. Moll, of the Moll photometer, you may have heard of it, who gave an elementary course in physics, and then there was Jan de Vries, who was a professor of descriptive geometry, projective geometry, and what have you; he was first rate. He gave a very good mathematical course. And then in analysis, the differential integral calculus and differential equations, we had a French professor, A. Danjoy. He died recently. I remember, he was very young and had a beautiful black beard. He didnít know a word of Dutch. He lectured in French. And although we knew French, it was not exactly easy, because the subject wasnít easy either, the way he treated it, with little epsilon and deltas and all that — really the fine points of analysis. So, one student volunteered to take notes. Iíve forgotten whether they were kept in Dutch or French. Thatís not important, but anyway, the notes were made available to help us. Danjoy didnít stay very long, somehow, and it was well realized at the university, by de Vries, the Dutch mathematics professor, that it had been difficult for us. So without much to-do, he announced that he would give a short course in analysis, and so he taught us all the things that we should know, that we had always been afraid to ask, so to speak, but that we should know about analysis and differential equations.
DeVorkin:This was his decision? This was not a request by the students?
Van de Kamp:No. It was one of these things that was brewing. It was announced one day that he would give a short course. It had to be done carefully. He didnít want to create the impression that he was hurting the feelings of his colleague. He just acted as a tutor, you might say. It was really very helpful, because he did it so beautifully. But again, I was lucky there, you see. In high school, I had van de Griend, the math teacher, and here, de Vries, Jan de Vries. It has to be qualified because there was another Professor de Vries, also a mathematician, in Amsterdam, whose first name was Hugo. We had physics, I mentioned already, with Moll, who also — this was very interesting — gave a special course in the afternoon on a very new subject: atomic theory as developed by Bohr. Can you imagine that?
DeVorkin:This is 1918.
Van de Kamp:1918. And Moll was a wonderful schoolmaster.
DeVorkin:He certainly was very up-to-date.
Van de Kamp:Oh, yes. This was new stuff. Wonderful. And then, we had courses in inorganic and organic chemistry. I can give you the names if you want. Inorganic was by E. Cohen, who later was killed by the Nazis. He was a very good friend and teacher of my brother, Jacob, who became a professional chemist. And then we had P. v. Romburgh in organic chemistry. Both courses in chemistry had laboratories one or two afternoons a week. No physical chemistry. That didnít play a role yet. And then we took a course in crystallography, of all things. All the different kinds of crystals. This is sort of mathematical, given by some very old professor named Wilchmann. He was German, I remember. Now, you may say, why did we take these courses? Because it was known that you should take these courses. How did we know? From a catalogue? No, there was no catalogue. One just knew these things. There was no president or anything like that. The university was a government university. Each year there was a rector magnificus, chosen from among the full professors, who formally was in charge of the university.
DeVorkin:Each year this position changed?
Van de Kamp:Each year or every two years, I think each year — Rector Magnificus. And there was no administration. You had to pay your 200 guilders tuition. You went to some little office, some government office, where a little fellow was sitting and you paid your money. By now, of course, they have catalogues, and itís just as bad as here. This is of interest, I think, I spoke with a good friend of mine in Holland, a distinguished professor of anthropobiology, Arie de Froe, who was Rector Magnificus almost ten years ago, during the student unrests the world over, and they were bad in Holland too. Occupation of buildings, that sort of thing. No violence. We talked about things now, how things have quieted down and there are no problems and students realize that they have to work in order to get ahead. To which I countered: ďOh, yes, itís not the students any more that are the trouble makers, now itís the professors.Ē Quite often. But thatís my personal peeve, that all the employed young professors who donít know how good they have it complain. Then I said, ďWell, how are things now?Ē ďOh,Ē he said, ďas compared with ten years ago, the paperwork at the University of Amsterdam has increased tenfold.Ē This is the curse of modern life. And he said, ďThe level of education has decreased somewhat.Ē
DeVorkin:Because of the paperwork increase?
Van de Kamp:I donít know whether itís related or not. In other words, the increased paperwork didnít help, certainly. Does it make anybody happy? I donít know. Of course, Holland is an overpopulated country, and they have real problems of meeting the needs of all the students. Itís not as bad in Holland as it is in France or Italy, apparently, where itís simply terrible. Where they donít build new facilities. In Holland, at least, they build new ugly high rise buildings for classrooms and to house all the people, and all the charm is gone. The Observatory of Leiden is not at the University of Leiden location any more now. Itís terrible. Astronomy is now in some high rise building outside of Leiden.
DeVorkin:Your first experiences in astronomy and physics, did you have any laboratory experiences in physics?
Van de Kamp:Yes, we had regular laboratory. We had teams of two. We determined wave lengths and we did minor experiments in physics. There was nothing going on in astronomy during those two years. Iím coming to that.
DeVorkin:So you did some spectroscopy?
Van de Kamp:Yes. It was assigned to us. The director of the laboratory at that time was L. Ornstein, the distinguished physicist, who had succeeded W.H. Julius. The name Julius may mean something, it should mean something to an astronomer; W.H. Julius, who was an expert on the sun, and his topic or hobby was anomalous dispersion. He gave a course, during my first year I think, that was in the framework of physics actually, but a course on the sun. And I wish I had the notes of that still, because what did we know about the sun in those days? He had enough to give a course. He was a charming old gentleman.
DeVorkin:His main interest seems to have been to explain the visible surface of the sun.
Van de Kamp:Yes.
DeVorkin:How we get a definite edge; how we get a definite surface. Do you recall the characteristics of this theory? Did he ever talk about it?
Van de Kamp:
Yes, but Iíve forgotten it now. It was all very strange to me. He was a charming old gentleman. One thing I remember about Julius was that in 1918, I think it was my first year there, or it might have been a year later, a fellow student and I entered the physics laboratory, which has now become the sociological laboratory, at Utrecht, and coming downstairs, (I can still see them coming down the stairs) are two gentlemen. One is Julius, with his beautiful white hair, and the other is a gentleman with lots of hair. And I said to my colleague, who was a physics major, as you would say nowadays, ďWho is the other fellow?Ē ďOh,Ē he said, ďthatís Einstein.Ē It was Einstein. 1918. ďOh,Ē he said, ďdonít you know Einstein? Heís the man of relativity.Ē I said, ďWhat is relativity?Ē I didnít know. And why was he there? Because Julius, in his laboratory, had built a tower telescope, for the specific purpose of testing the red shift of the sun, which was one of the three tests of Einstein. I donít think he ever succeeded.
Other people didnít succeed very well either. It remained a very ticklish thing. But thatís why Einstein was there. It was the very first time I saw Einstein. In a separate chapter, I can tell you more things about Einstein. Actually, just about this same time, another friend of mine in Holland, a student friend, Hobma, (whoís still around) had an experience with Einstein. If you ever go to Holland, you might interview him; heís 82 but heís all there; heís very well informed about physics in Holland, because he studied with Julius and all these people, and was a chief assistant in the laboratory. Moreover heís a charming fellow. Hobma tells me this story: He was in the laboratory, and in comes the janitor. The janitor was known as ďthe CyclopsĒ because he had only one eye. And the Cyclops told my friend, Hobma, ďWhat shall I do? Thereís a man at the door.Ē Hobma said, ďWhat do you mean, thereís a man at the door?Ē ďOh,Ē he says, ďthereís a Jew there, a little Jew. He wants to come in and see the professor.Ē Hobma checked it out — it was Einstein. But you see, there was no malice in that. This was before 1940. Amsterdam had 100,000 Jews; in Holland there were Jews. Iím not saying there were no prejudices against Jews. There were clubs, etc., that refused Jews and all that. But it wasnít anywhere near the anti-Semitism here and now.
Well, anyway, in those days we had never heard the word ďanti-Semitism.Ē But we knew that there were Jews; in my home town, for example, there were a few dozen Jews. And why were they singled out? Because there were so few of them, and because they were so very special. They were, let me say, more interesting perhaps than the average citizen. And they were strange; we had two who lived near us, and on Friday night my mother had to go there and light the oil lamps because they werenít supposed to do that. So they asked for it, in a sense. Everybody made jokes about the Jews, and people still do. The best Jewish jokes, as a matter of fact, come from the Jews themselves. The best Catholic jokes come from the Catholics. I think itís healthy, if people can make a joke of themselves. We wonít go into that right now. But anyway this janitor was just confused. It was Einsteinís quiet bearing. I was reminded of this when I saw my old friend last year, and he told me this again. We were reminiscing about the old days.
DeVorkin:What was Einstein there for?
Van de Kamp:The first time that I saw him, he was there to talk to Julius about the red shift. That other story, I donít know at what occasion that was, but itís likely that Einstein frequently visited there.
DeVorkin:This was at Utrecht?
Van de Kamp:Utrecht. Yes. I repeat, if you ever go to Holland, try to get hold of this man, Hobma. I can give you his address. Heís a charming fellow. He used to be a high school teacher, a very high grade, high level high school teacher. A very inspiring man.
DeVorkin:I appreciate that. What about astronomy at Utrecht?
Van de Kamp:Well, now we get to the time I got my Candidaat.
DeVorkin:Did you have any astronomy the first two years before you got it?
Van de Kamp:Yes. I told you, I took a general course and a course in spherical astronomy with Nijland. I also took a course in how to calculate eclipses, with Nijland, and I think he gave a course invariable stars. Also, we had a colloquia every so often. I remember I had to speak at one, and I was assigned (and fate played a role there) to speak on Shapleyís work, the recent work by Shapley which kicked us away from where we are.
DeVorkin:This is the globular clusters.
Van de Kamp:24,000 light years away from the center (of the galaxy), something like that. And I reported on that, and little did I know at the time that I would come back to that same problem later on.
DeVorkin:What did you find most interesting in astronomy at this time?
Van de Kamp:
Nothing in particular, really. Just the whole field of astronomy. And then, after the Candidaat, I started doing some practical work. The observatory (the word ďdepartmentĒ didnít exist in those days) at Utrecht was very small. There was a professor (Nijland) a lecturer, whose name was Jan van der Bilt, who played a very important role in my life, and then there was an assistant to run the clocks and that sort of thing, and a janitor, and a part time computer. And that was the whole business. Now, after the Candidaat, Nijland turned me over, literally, to van der Bilt, who was supposed to teach me practical astronomy. I took with Nijland a course in Celestial Mechanics and Orbit Computation, the name of the course was ďTheoretical Astronomy,Ē but I also took lots of mathematics and physics courses during the second two years. But this meant a great deal in my life to be turned over to Van der Bilt who started his life as a man in the Navy. He was a Navy man at heart.
In connection with that all the Navy officers, were in touch with observatories, (at least with the observatory at Utrecht,) every so often. They had to learn how to work with the sextant and that sort of thing. But the details are not important at the moment, Van der Bilt had been offered the position of lecturer, weíd call it assistant or associate professor, at Utrecht, and it was my good fortune to fall into his hands. So we did practical work together, which meant adjusting instruments and working with the sextant and the transit instrument to determine the time. In those days you determined the time from the stars. And if it was cloudy for three weeks, you were in trouble with your clocks; radio was just beginning to come in. Well, at any rate, Van der But took an interest in me, and I liked him. He considered Nijland very old fashioned, and he said, ďThe sooner you get away from here, the better. You should go to Leiden or Groningen and do some Ďmoderní astronomy, along with some photography which is the new thing nowadays.Ē
DeVorkin:Well, what was the limitation at Utrecht?
Van de Kamp:Only visual telescopes. I think it was an eight inch refractor which was called a ďlarge telescope.Ē I worked also with a micrometer (at that time) to determine the positions of asteroids with respect to stars nearby, But according to Van der Bilt, there was no future in that. He was a very far-sighted person. He advised among other things, that as a young student I should get to a larger observatory as soon as possible. It was no reflection on Nijland as such, but — a larger observatory. Then, it happened; Jan H. Oort was assistant in Groningen, J.C. Kapteyn died in 1922, and before that he was succeeded by P.J. van Rhijn who had been his chief assistant. And Oort was van Rhijnís assistant, after having been assistant to Kapteyn. Then Oort was invited by Frank Schlesinger to come to America, where he stayed for two years at Yale.
DeVorkin:This is all approximately 1922 - 4?
Van de Kamp:1922-4, yes. Because Oort went to America in 1922.
DeVorkin:Because Schlesinger would have just gone to Yale at that time.
Van de Kamp:Yes, 1922. So van Rhijn needed a new assistant, and van der Bilt talked to van Rhijn and said — something like, ďI have this fellow van de Kamp here. Heís very close to his doctoramdus now. Take him as assistant. He hasnít got his doctorís degree, but so what. That doesnít matter. Heís good.Ē To make a long story short, I was offered the assistantship, and I went to Groningen to talk things over the van Rhijn and there I met Oort and Jan Schilt who was still there. Oort was very helpful in finding me a place to live because I decided that this was wonderful for me; my first position, terrific salary, 2000 guilders a year, which was quite good.
DeVorkin:You hadnít finished your work.
Van de Kamp:No. I started there September the 4th, 1922, I remember. But then I went back to Utrecht to get my doctoramdus.
DeVorkin:What did you have to do for the doctoramdus, an exam?
Van de Kamp:Well, an exam. The exam in those days was very simple. You just went to your professors and arranged a preliminary exam at the home of each professor. It was a private arrangement. Then they would get together and say, ďWell, at such and such an afternoon, letís all of us get together for an hour and finish this off.Ē Again, there was no administration involved. Then they would scribble on a piece of paper that everything was OK, and then you got your diploma. And you paid 50 guilders I think or something like that, for expenses. Then I got my second diploma, which I just saw there a minute ago, and no cum laude this time, because I had tasted blood and I was in a real research institution, and I neglected my preparation for my exams. But I passed anyway.
DeVorkin:So the practical work that you did for Van der Bilt was a true research experience? You still thought you were learning, rather than doing real research?
Van de Kamp:Oh, yes. There was no pretending, like the little kiddies now ďdo researchĒ in grammar school. We were just learning. It was the old system of the master and the apprentice, and I still believe in that. Thatís the way to educate people on all levels, and not just use big words. Never use big words. I donít think Einstein ever used the word ďresearch.Ē Iím sure he never did. He just tried things, and played with things. So the two years with Van der Bilt played a very important role. I have a terrific correspondence with Van der Bilt. Itís worth anything for archives. Van der But was a very critical man, and in a sense, the-letters are interesting, I think, historically.
DeVorkin:During what period do you have these letters? (Dr. Van de Kamp is examining his files)
Van de Kamp:This goes up to Ď37.
DeVorkin:And it starts with Groningen? 1923, from E. Hertzsprung, what is he saying here?
Van de Kamp:Oh, this is something. He inquired about something. Proper motions of the Hyades. Thatís interesting, in January, 1923, van Rhijn thought I should make a redetermination of the proper motion of the Hyades. And so then I wrote to Hertzsprung about some advice. And at the same time, I got the invitation to go to America.
DeVorkin:This was by invitation?
Van de Kamp:Yes. Well, itís really very simple. Kapteynís last paper, in the BAN No. 14, deals with the systematic errors of proper motions of the Boss Catalogue, and if you have never seen it, you should look at that article. There he proposes a scheme by which these systematic errors could be determined, from measuring proper motions of faint stars. He slipped up there, scientifically. But thatís a minor matter. That was straightened out later. Anyway what was later called the Kapteyn Astronomical Laboratory relied for its work on material from the outside, because there was no telescope at Groningen, and Kapteyn had paved the way for that, because Kapteyn was accepted the world over, and so, wrote particularly to S.A. Mitchell and said, ďMr. Mitchell, as Kapteyn suggested in publication BAN No. 14, this problem could be attacked or solved by repeating early parallax plates, taken as early as six or seven years agoĒ (now we deal in intervals of over 50 years) ďand would you take these plates and send them to Groningen,Ē practically ordering him (to do so). Van Rhijn was not very tactful in that respect. The Dutch are not very tactful. ďAnd then, send them to my assistant Van de Kamp and he will measure the plates and analyze them. This was S.A. Mitchell, SAM, as we called him — Sam — Kovalinko used to call him ďSex Appeal Mitchell.Ē Then Mitchell wrote back. I have that letter here. Saying ďrather than us sending the plates to you, why donít you send Van de Kamp over here?Ē
DeVorkin:This was Mitchellís request.
Van de Kamp:Mitchellís request, ďwhy not send him here? our Dr. Alden is also interested.Ē H.L. Alden. Well, I found it was a delicate situation, because Alden had started this work, following Kapteynís suggestion, and now Mitchell brought in this unknown quantity from abroad, which Alden didnít like at all. Alden and Mitchell didnít get along anyway.
DeVorkin:Is that possibly why Mitchell asked for your presence?
Van de Kamp:No, I think Mitchell asked because he was pleased to have this expression of interest from van Rhijn, and he thought in this way — I think in a way, this was correct — that if this man comes over here, then Alden and Van de Kamp can do it together, and more can be done in a shorter time. Well, anyway, I came and it was a bit of a blow, I think, for Alden, that somebody else came. Alden wanted very much to get something for himself. He had been doing slave labor on parallaxes. In the first place, Alden was 35 and I was 21, so that was more acceptable. If I had been Aldenís age and very aggressive and all that, it might have been difficult to work together. But under the circumstances, it worked, and looking back on it, I learned a lot from Alden. He was a good man. And I think between the two of us, we did better than either one of us would have done, because he contributed the technical knowledge. He was an excellent observer and measurer — all these things that played a role and still play a role — while I had formal theoretical knowledge. I think it worked out well. So this was to be for one year, then, and Mitchell offered $1500 also, to take care of my going and coming, which meant $200 per crossing in those days, lovely ocean trips. Except that coming over in February on the old SS Ryndum wasnít so lovely. The weather was terrible every day. And then, an adequate salary of $100 a month. One could live on $30 a month in those days very easily, as a matter of fact. And I had living quarters on the mountain there, and it worked out very well.
DeVorkin:That was the University of Virginia?
Van de Kamp:Yes, the University of Virginia. So in a year we werenít ready, so Mitchell said, ďStay another half year,Ē which I did. And by that that there were complications.
DeVorkin:What were they?
Van de Kamp:When I left Groningen, van Rhijn said, ďWell, this is wonderful, of course, for astronomy, also for you, this experience, to go there to America. But you must come back.Ē I said, ďYes, of course Iíll come back,Ē and I had fully intended to come back, because I thought that I still had a lot to learn from van Rhijn and the people in Groningen. And as I realized later on, I couldnít have learned much from Mitchell. Mitchell was basically an organizer and a hard worker, but he didnít know too much really. From Alden I learned more. So I fully intended to go back. But then my successor, Klein Wassink, had been broken in, and I think he was working on the proper motions of the Hyades at Groningen, So my successor had been broken in, and apparently he was working out all right, And I think, I donít know all the details, but I think van Rhijn hesitated to kick him out again. And Mitchell wanted to keep me in Virginia. And so van Rhijn wrote to me and said, ďOf course, you stay in Virginia, chance of a lifetime and all that, why should you come back here?Ē I said, ďI want to come back because I think I canít learn anything from Mitchell, I can learn more from you, ďwhich was perhaps an over-estimation, but, to make a long story short, I was virtually told by van Rhijn, ďDonít be a fool, you canít come back, Klein Wassink is doing all right.Ē
DeVorkin:Was he sincere? Did he see a true value of you being in the United States?
Van de Kamp:Oh, yes, I think so. He had been in the United States himself, and of course the United States, in those days, was very much the promised land in astronomy. It is still, to some extent, thereís no doubt about it. You know how they have big telescopes everywhere now. If you want to do first rate work in radio astronomy, you might well consider going to Holland, for example, right now. I can tell you more about that later on, in connection with other things. So I didnít mind particularly. But meanwhile, as the saying goes — (it sounds like a drama, doesnít it, in the movies, ďmeanwhileĒ —)
DeVorkin:Itís a very dramatic part of your life.
Van de Kamp:Of course it is. I had come in March, 1923, and then in October, A.N. Vyssotsky came. I know the exact date, I can check that. Vyssotsky came here through Struve. Vyssotsky like so many of these Russians, had fought the Communists, and they were left high and dry, because they lost. The White Russians lost, as we all know. These White Russians were taken care of somewhere, temporarily, and were given a chance for education, and Vyssotsky had been in correspondence with Struve. And Struve with Mitchell. Mitchell needed somebody else for the observatory, and Mitchell asked Vyssotsky to come over, and he came over. So Vyssotsky and I became great friends. We lived together from Ď23 to Ď27, actually, till I got married. We lived in the same town and worked together. So then, when it had appeared that I wanted to go back to Groningen, as I had shouted from the housetops, then Mitchell said, ďWell, itís too bad, we would like to have kept him.Ē Vyssotsky said, ďWell, I know somebody in Paris — Michael S. Kovalenko. Why donít you ask him?Ē Kovalenko basically was a mathematician and engineer. But Vyssotsky had told him to go to Paris to study astronomy, ďbecause maybe I can get you a job later.Ē He was given to some fund for stranded people. And thatís the way it worked. And so, Kovalenko was offered a job to succeed me, at the time when I was fully determined to go back to Groningen. Then it appeared that I would go back to Groningen, so there was a problem, for Kovalenko was coming. Well, Mitchell was very very helpful in that respect. He said, ďWell, OK, you have to go somewhere else, then, and Iíll help you.Ē He wrote to a few places.
DeVorkin:Where did he write? Do you know the number of places?
Van de Kamp:He wrote to three places, I think. But the place which worked out was Lick Observatory.
DeVorkin:Do you know the other two places?
Van de Kamp:Gosh, I may be able to trace it. I donít know. From correspondence. But I donít know it right now.
DeVorkin:OK, we can leave that for now.
Van de Kamp:And then, R.G. Aitken was in charge at that time, and Aitken said, ďWell, we have the Martin Kellog Fellowship, which really is for Ph.D.s but Van de Kamp hasnít got his Ph.D., but perhaps we could make an exception.Ē Mitchell had told only good things about me. Then, the only hesitation Aitken had, and I can show you that letter some time, is that, ďWeíve had some trouble with foreigners who canít take our food, here.Ē And Mitchell said, ďOh, Van de Kamp eats everything.Ē Something like that. So there was no problem at all. It was solved.
DeVorkin:Do you know who Aitken was referring to?
Van de Kamp:He was referring to ďdyspeptic foreigners,Ē Thatís all I know. (Dr. Van de Kamp now reads letter from Aitken to Mitchell)
Van de Kamp:(reading) ďDear Mitchell: There is a vacancy in the Martin Kellog Fellowship, and I have been looking for some time,Ē blah blah blahÖ well, I wonít read the whole thingÖ This was June 4th, 1924. ďIf you would let me know what his courses were at Groningen or LeidenÖ Utrecht. Let me in this connection bring up another matter bearing upon the point. We have had some difficulty in the past with dyspeptic foreigners. The conditions here are such that our unattached people, living in the dormitory, are expected to get their meals at the general boarding house. This is well managed. The food served is good, and I have no hesitation, when occasion makes it desirable, to go there for my own meals, or have any one of my friends there. If Mr. Van de Kamp is normally healthy, I think that he would enjoy conditions of life here, but in view of past experience, I want to proceed a little cautiously.Ē Isnít that nice? Maybe youíd like to have a copy of that.
DeVorkin:Yes, we certainly would.
Van de Kamp:Itís very much an Aitken letter.
DeVorkin:Did you ever learn the names of the people he was referring to?
Van de Kamp:No. I didnít ask. This is a letter two weeks later. ďYour letter quite confirms the idea that we should like Van de Kamp as Martin Kellog fellowĒ blah blah blahÖ ďPlease let me know,Ē thatís all.
DeVorkin:When you took the fellowship, was there any understanding before you came as to what you were going to be doing for research?
Van de Kamp:Gosh, I donít know. Here is the letter of my appointment: ďMy dear Mr.
Van de Kamp:It is a pleasure to notify you officiallyÖ therefore you can count on $1200 a year.Ē Thatís a lot, you see. ďWe should be interested to know something of your ideas concerning the work you will do while here. If you have no definite program worked out, I would suggestÖĒ blah blah blah.
DeVorkin:What was he suggesting?
Van de Kamp:Well, suggesting, one, that I use the photoelectric cell photometer attached to the 12 inch refractor, ďI think the instruments and the conditions here are good. Dr. Stebbins has the same opinion, after he worked here last year.,Ē ďOf course there will be opportunity for you to become familiar with the other work, and to take part in it, but I strongly recommend that you have a definite program of your own, in addition to such general participation.Ē
DeVorkin:So he was interested in the photoelectric work that Stebbins did?
Van de Kamp:Yes. Well, — then, — what I suggested at that time, because it was something of common interest was that I determine radial velocities of faint stars. And I got my doctorís degree on that.
DeVorkin:You received the doctorate within one year.
Van de Kamp:Yes. Because all the residence requirements were waived because I had taken all the courses already, in Holland, I told them which courses and they took me at my word. There was no paperwork involved. They just believed me, I had to pass examinations.
DeVorkin:Who administered the exams? Aitken, I imagine.
Van de Kamp:Yes, there was a committee, R. Trumpler and J.H. Moore. And the physics professor was E.P. Lewis, and the math professor was Kaskell. And I also was examined by Leuschner, on the preliminary exam. This was a very nice experience. Because Leuschner said, ďOh, you have been at McCormick, you know all about parallaxes, I know nothing about parallaxes, tell me about them.Ē And I had prepared Leuschnerís method, a modification of the LaPlace method for determining orbits of asteroids. But we talked about parallaxes. W.W. Campbell would turn up once in a while, at the observatory, and thatís where I met him.
DeVorkin:What were your impressions of Campbell?
Van de Kamp:Oh, very charming, distant, dictatorial person. Everybody was scared of him in those days. Everybody was scared of bosses. As contrasted with Aitken, whoís such a gentle, gentle person. Always a bit this way: (sotto voce) ďNow, you mustnít you mustnít do this, you must ÖĒ He was so gentle. Mrs. Aitken was tough. When Van der Bilt knew that I was going to California, (and I should get that letter now but I havenít got it here) he said, ďOh, that will be wonderful. The people there are very nice and very hospitable, and when I was thereĒ — of course, he said that they were terribly chauvinistic over there in California, terribly chauvinistic. I found out that there were chauvinistic Americans, but even more chauvinistic Californians, and a man like W. H. Wright, whoís a very fine fellow, didnít like the East at all. It was a foreign country, as far as he was concerned. Probably worse than Europe, you see.
DeVorkin:How did you react to that?
Van de Kamp:Oh, I didnít know what to do, really, I was still very young and didnít talk back. But Van der Bilt wrote the following. He said, ďOld Aitken is a very nice man, and Mrs. Aitken, she will treat you as a mother.Ē And this was true, in a sense. She was also very much the Mrs. Director, very much in charge, because on the mountain, there are all these families. There are always problem with people living so close together. The men got along fine with each other, as scientists, but you know, the women, itís more difficult, of course.
DeVorkin:Do you think that ever affected research?
Van de Kamp:No. I donít think so. Well, anyway, then Van der Bilt continues to write: ďWhen I visited the Aitkens at their house, Aitken said, ĎOh, Mr. Van der Bilt, youíre from Holland.íĒ Oh yes, Van der Bilt said, ďYou will find, wherever you go, it means a great deal that you are from Holland. The Americans are nuts about that.Ē So Aitken said to Van der Bilt, ďOh, you are from Holland.Ē ďYes.Ē I have some Dutch ancestors, let me see —Ē And then Mrs. Aitken interrupted and said, ďRobert, rubbish, your ancestors and mine, theyíre all cattle thieves.Ē But it sounds reasonable, coming from her the way she was. And poor Aitken, he tried so much to dig up a Dutch ancestor.
DeVorkin:That would stop him at that point?
Van de Kamp:Yes, Iím sure that stopped him. He didnít have much of a chance with Mrs. Aitken around. But they were very happy, I think.
DeVorkin:Did you work with the Crossley, then?
Van de Kamp:No, with the 36 inch refractor, I didnít build my own instruments. I couldnít have done that. I used a small six-inch spectroscope, with a light prism camera, to get the faintest stars possible. And the man of course who helped me more than anybody else was R.J. Trumpler. Trumpler was a wonderful man, And J.H. Moore. Everybody was helpful. I talked with Moore because he was a radial velocity man. Trumpler of course was very much the cluster man.
DeVorkin:Had he started working on clusters at that time?
Van de Kamp:Oh yes. All his life he worked on clusters, Trumpler had a large family, all those small children — I remember carrying Cecelia in my arms. I donít any more now. Sheís Mrs. Weaver now. Sheís a big girl. But I have pictures of that. I took lots of photographs that year.
DeVorkin:Was he making H.R. diagrams at the time?
Van de Kamp:Yes, I think so, or shortly afterward. These four different groups. He was a good man, Trumpler. And a hard working man.
DeVorkin:Did you ever talk to him about the significance of the different groups of cluster diagrams that he made?
Van de Kamp:No. No, I didnít.
DeVorkin:Did you ever think about them at that time.
Van de Kamp:No, I didnít. I just thought in terms of getting more radial velocities of faint stars. And then I was lucky. I had the regular shift, two, three nights a week, but then Aitken, although he was called Associate Director or Acting Director by that time — observed double stars. But for double stars, you need very good seeing. And moreover, Aitken wasnít that young any more. So frequently, he would decide that the seeing was no good for him. He would come to my room and say, ďYou can have the rest of the night.Ē And I welcomed that, because the more stars I could get, the better. I didnít need good seeing really because I used a wide slit, and average seeing was good enough for me.
DeVorkin:Were you staying in the dormitory?
Van de Kamp:Yes. It was a separate building. And there was a nice group of people. I made many good friends there. One of them was E.F. Carpenter, who later went to Arizona. We always remained good friends.
DeVorkin:He did binary work, didnít he?
Van de Kamp:Yes he did. Spectroscopic doubles, such as U geminorium. Then there was Ching Sun Yu, the Chinese, who later went to Hood College, in Maryland, where he still may be for all I know. Then there was Hamilton Jeffers. But while we were there, Jeffers got married to the secretary. That marriage didnít work out. Thatís another matter. Jeffers was the oldest unattached man, and he presided at the dining room table, where we all ate. We had to eat together with the workmen. There was a Mr. Osen, a carpenter, very nice fellow: a Mr. Young, electrician, who was sort of a rough guy, and then there was Dorothy Havens, later Mrs. Chappell.
DeVorkin:Did you have any contact with the Shames?
Van de Kamp:Yes, well, the Shames were down the mountain, you see.
DeVorkin:They were at Berkeley?
Van de Kamp:They were at Berkeley. But they would come up once in awhile. Of course, this is over 50 years ago now — they were barely 30. They had a little boy with them. I forget whether it was Whitney or the other one. I donít know. And Shane was known for making the trip from the foot of the mountain to the top of the mountain in 40 minutes. He was a wild driver. And I remember, he looked wild in these checkered black and red shirts.
DeVorkin:How did you find the general conditions for research at Lick?
Van de Kamp:Oh, good.
DeVorkin:The scientific attitude was good, positive?
Van de Kamp:Wonderful place. I enjoyed it very much. By the time the year was over, I was offered a position for the next year. They would have continued me. But by that time, Alden had been offered the position to go to South Africa, to run Schlesingerís telescope, and had accepted that, because he was glad to get away from Mitchell and so he went from the frying pot in the fire. He was unhappy with Schlesinger, who was in his way a dictator I guess. But anyway, I was offered the instructorship, $2000, I remember, by Mitchell, and I thought Iíd better accept it. Also, in California, I felt I was so far away from Holland I would never get back again. This was practically before the invention of the airplane, you remember. So I went back, and I would have enjoyed staying another year, perhaps, at Lick, but it appealed to me to go back to Virginia.
DeVorkin:And Vyssotsky was there.
Van de Kamp:Vyssotsky was there. Vyssotsky and I started our big work, and I did odds and ends of different pieces of research, diameter of Mars, you may recall, and then work on the absorption. (references AJ 1920, 1932)
DeVorkin:How would you relate the influence of Van Rhijn upon you?
Van de Kamp:Well, he had some influence, I think. He was not a strong man, not a dynamic person. He felt very much that he had to live up to the reputation of Kapteyn. Van Rhijn was a very modest man. He was one of the most natural people I ever met — ďHow can I live up to that, you see?Ē Kapteyn, the great Kapteyn — He did his best. I had been in Groningen for only five months, which wasnít very long. They had a system there where everybody made notes in big books, which were kept, so they called them just scrapbooks, which means the first draft. It was very interesting to read through these in Kapteynís own handwriting, where he would say, ďLetís try this. No, it doesnít work. Letís try this.Ē
DeVorkin:Would you say these books still exist there?
Van de Kamp:I hope so. I have a feeling that some of them have disappeared, by accident. But youíd better check with Blaauw about that. Adriaan Blaauw would know.
DeVorkin:That would be a very good idea. Iím interested in the organization of science in the Netherlands, organization of astronomy, I should say, during reconstruction after World War I, and the development of the BAN. You were still a student at Utrecht, of course, but did you begin to become aware of the astronomy that was done at the other observatories, through the BAN?
Van de Kamp:Yes, through the BAN. Itís difficult to remember. Before the BAN, the Dutch published mostly in the ASTRONOMISCHE NACHRICHTEN or in their own publications. In Utrecht for example the publications were in French, and then there were the German publications. Then partly as a reaction to the First World War, and partly the initiative of de Sitter, the BAN was born. He said, ďLetís get together and have our own publication, and not depend on the ASTRONOMISCHE NACHRICHTEN and so on. So then the institutes combined.
DeVorkin:Was this a reaction then against the ASTRONONISCHE GESELLSCHAFT?
Van de Kamp:Well, I donít know. But why should we publish in German? (The Germans havenít been that nice. Ever.) Also, it was basically a practical matter. There are five of us, there are enough institutes so we can have our own magazine. No it doesnít exist anymore, as you know. Again the Dutch took very much the initiative to disband the BAN and establish ASTRONOMY AND ASTROPHYSICS, which is the next step, isnít it, still higher up.
DeVorkin:Thatís even a larger consortium.
Van de Kamp:Yes. And there again, I remember when Blaauw told me about it I said, ďOh my gosh, the dear BAN that started only yesterday, in 1922 —Ē ďWell,Ē he said, ďwe have to look ahead. It makes sense that the western European people combine.Ē
DeVorkin:You had contact with Blaauw at that time?
Van de Kamp:No Blaauw is 12 years younger than I am. Blaauw didnít exist then. Blaauw and I become acquainted 25 or 35 years ago. We have remained good friends ever since.
DeVorkin:In the initial period, you say de Sitter was the guiding influence. Who supported it strongly? And did anyone feel it was a bad idea?
Van de Kamp:I donít think anybody thought it was a bad idea. I think everybody took to this as a duck to water. It seemed natural.
DeVorkin:What about the decision to print it in English?
Van de Kamp:Well, the Dutch knew that English was the international language. We knew it long before everybody else did.
DeVorkin:Was it the influence of Kapteyn?
Van de Kamp:Kapteyn published everything in English. Yes. I think it played a role, probably, in Kapteynís relation to S. Newcomb, D. Gill and to America.
DeVorkin:To Hale especially.
Van de Kamp:To Hale. They were very close. Yes.
DeVorkin:Do you know any stories, possibly from van Rhijn, about Kapteynís impressions of Hale, Adams and American science, the growth of great observatories?
Van de Kamp:No. You will find out a lot more in that book here. No, I didnít stay long enough. We didnít get to know each other too well, because van Rhijn was so busy. He said, ďWhen we have a little more time, weíll make music together.Ē He played the viola. I played the violin. And we did it once after I had come back from America, much later.
DeVorkin:Did you have any impressions at that time?
Van de Kamp:No, except that he had this great admiration for Kapteyn, and this feeling of responsibility.
DeVorkin:Responsibility, did you say?
Van de Kamp:To have this responsibility to carry on the work of Kapteyn. Historically speaking, now, van Rhijn played his role, thereís no doubt about it. But the natural successor to Kapteyn was Jan Oort. And Jan Hendrik Oort, I think even goes beyond Kapteyn. He benefited from all that had been done. Thatís so. Kapteyn did the best he could. Kapteyn to the last defended the Kapteyn system, till Shapley pointed out that we are not at the center, which is in Sagittarius somewhere. There was this very strong feeling of loyalty, I think of van Rhijn who said: ďShapley canít be right.Ē Now admittedly, Shapley had a lot o luck, because he dealt with only 13 Cepheids or so, and gosh — it could have gone wrong. But it didnít go wrong. And the whole reasoning of Shapley of course is simple, very simple reasoning. To go from the Cepheids to the red giants, and then to the total luminosity. The simplest approach possible. Building everything on the limited number of globular clusters. Their merit was that they are so bright. You could see them. So far away. While Kapteyn and van Rhijn worked all the time on stars and proper motions and magnitudes. They didnít get out very far. And without knowing it, they were bothered by absorption, of course.
DeVorkin:When did you first begin studying interstellar absorption?
Van de Kamp:1930, after Trumplerís paper, I became very much interested.
DeVorkin:It was Trumplerís paper that —
Van de Kamp:— that got me started, yes, Iíve written all of this up in a little booklet which of course you have — the Shapley Lectures — five papers written for Shapleyís 80th birthday. My contribution is ďThe Galactocentric Revolution.Ē
DeVorkin:Thatís right, I have that.
Van de Kamp:Shapley himself wrote me a letter after that, a lovely letter, saying that ďYou have made it a lot easier for future historians.Ē — I can give you a copy of that, if I havenít done so. I think heís right. Nobody else has done this. Itís not a matter that Iím so smart, but I was historically interested, and I lived through this whole period, you see. And I stopped in time, which is very important. I stopped at radio astronomy. When radio astronomers came in, there I stopped, somebody else has to take care of that. There was Shapley, and then the next big step was B. Lindblad in 1925, galactic rotation, and that really — that did it. Nobody could hold out any longer. And then of course Oort, who confirmed it observationally. And then 1939, absorption in space, which polished up things, which explained, perhaps clearly, why Kapteyn have gone any further, and also showed incidentally that Shapleyís universe was too large, had to be reduced. I reduce it very much, much more than is done nowadays, but I think the final word isnít in yet. I donít know how long it will take, before we really know these distances.
DeVorkin:Lindbladís work on galactic rotation is interesting, from an analysis of the systematic change in space velocity with spectral class.
Van de Kamp:Yes.
DeVorkin:By the turn of the century, it fascinated Kapteyn, and he thought it was an evolutionary sequence.
Van de Kamp:That was the idea, in those days.
DeVorkin:Did people, while you were being trained, during this time, in the early twenties, still think that way?
Van de Kamp:No. I remember specifically that, in the elementary course which Nijland gave, I think in 1918, and it may have been possibly a year later with another course, I donít know, but it doesnít matter, that he mentioned what was called the Russel Diagram in those days. He also spoke about evolution, and said the original idea of Kapteyn was that the stars started as blue stars, and then they became red, and so on, they start going (moving) fast, or something like that, That was the Kapteyn idea, I think. Campbell also had this idea. And then H.N. Russellís idea was of course the inverted seven. But the Kapteyn idea was already overboard, really.
DeVorkin:By Russellís time?
Van de Kamp:Yes, by Russellís time, which was 1913, wasnít it?
DeVorkin:What was the regard for Russellís work by Nijland and others?
Van de Kamp:Oh, very great.
DeVorkin:His theory of evolution, or his basic work on the diagram?
Van de Kamp:Well, both. Yes. Of course, then it remained for others to point out that the essence of the diagram had been discovered already by E. Hertzsprung in 1905; as I always tell my students, if anybody asks you who invented something, first youíd better say ďHertzsprung,Ē itís probably right.
DeVorkin:Did you ever talk to Hertzsprung about that?
Van de Kamp:No. Hertzsprung was a most unapproachable man, But the differing attitude of Hertzsprung and Russell to the diagram are quite interesting. Iíve heard Russell speak, ďand one can plot the stars in the diagram, which sometimes is referred to by my name.Ē So this was in the l920ís. And Hertzsprung made it very clear that he thought it was terrible to have personal names attached to a diagram. I agree with him. Why not call it, as I do for my students, a spectrum luminosity diagram? And not bother them. Because if you say ďHertzsprung,Ē in the exam what comes back is HerschelĒ or something like that. They get things mixed up all the time. Why should they be bothered? The elementary students, I mean. But it was for a long time the Russell Diagram. And then, if Iím not mistaken, primarily through B. Bokís action, it became the Hertzsprung-Russell Diagram.
DeVorkin:Why do you think Bok was the one that championed this change?
Van de Kamp:For two reasons, I think, or one. Bok was a man with a very strong feeling of justice, though he probably had no personal love for Hertzsprung at all. Neither Hertzsprung or Russell are lovable people at first sight. When you got to know them, possibly, yes, and of the two probably Russell was certainly more approachable. But I canít tell the whole story. Jan Schilt might know a little more about it. But it was Bokís feeling for justice, and the fact that heís a stubborn Dutchman, of course, and pushed. I think he pushed it through. Ask him. If he still remembers. But tell him, thatís the way I remember it. You can tell him. Weíre very good friends.
DeVorkin:Iíd like to be able to do that, if I get a chance to.
Van de Kamp:— So now itís the H-R Diagram, which is a terrible name of course. The spectrum-luminosity diagram. We speak about mass-luminosity relation. Itís the same thing. The mass-luminosity relation, who made it first? You guessed it, Hertzsprung. Of course. Itís the same thing, isnít it, basically?
DeVorkin:Right. When you first were exposed to the H-R Diagram, what was your feeling for the reality of the difference between giants and dwarfs? Had that been pretty well settled by 1920?
Van de Kamp:Oh yes. That also came from the spectrum of course. Of the M stars and K stars.
DeVorkin:Through Adamís work?
Van de Kamp:Yes. Kohlschutter too. We were taught in Holland at least, that Kohlschutter gave Adams the idea.
DeVorkin:Could you expand on that?
Van de Kamp:No, just, that, I recall, is what Nijland taught to us. Adams was a very nice man. I shouldnít make an issue over that. I donít say that Adams stole anything. I donít think it is that way. I mean, people benefit from each other. Kohlschutter apparently was in California.
Van de Kamp:And I think there are many places in the literature where you find a reference to these luminosity criteria as being due to Kohlschutter and Adams. And Adams probably did a lot more observational work on it afterwards.
DeVorkin:What about Kapteynís role? Did you ever hear any stories about his role in the development of spectroscopic parallaxes?
Van de Kamp:No, He may have thought the same as I do. I donít think theyíre very significant.
DeVorkin:Kapteyn had almost a lifetime search for interstellar absorption.
Van de Kamp:Yes. He did. So did van Rhijn who wrote a long paper on it, and couldnít find anything. He didnít go out very far. Kapteyn was aware of the fact that absorption might have played a role, I think, in explaining the petering out of stars. But then, I think that observational evidence was sort of against it. Even in Shapleyís work, if I recall correctly, itís in the HARVARD BULLETIN somewhere. Shapley studied the color of Messier 3, letís say, which is at a high latitude, and found that there was no reddening, over that distance of 10,000 light years or so. So why couldnít he find the reddening? Because when you go in that direction, you step out of our own system. Thereís no chance for any reddening to accumulate. If you take a globular cluster at low (galactic) latitudes, the situation may be different. But at a very low (galactic) latitude you may not see them at all. They just had not been studied. So there was this terrible situation always, due to this selection effect which is always at work. I think Shapley makes the statement somewhere, that we neednít worry about the interstellar absorption because (of his work). This was because Shapley did not pay attention to the fact that it is a latitude effect. This remained for Trumpler. Trumpler didnít study globular clusters. He studied open clusters, which were just in the midst of all the mess. No wonder he found the absorption.
DeVorkin:How close were you to all of this work in the twenties? Were you actively following the problem of galactic structure?
Van de Kamp:I think I did. I think one could, because whatever was published in those days, one could read. There wasnít that much that you couldnít read. Certain things, papers on the interiors and atmospheres of stars, I read, but anything that pertained to galactic structure, I would read. A very important name, of course, not to be forgotten, is Stromberg.
DeVorkin:Yes, Gustav Stromberg.
Van de Kamp:Gustav Stromberg, whom I knew, who discovered what he called the asymmetry in stellar motions. Which of course is the thing that he didnít quite interpret. He was a bit mystical about it, I think.
DeVorkin:Did this eventually develop into the Botlinger diagram?
Van de Kamp:Itís the same thing, sort of. The Botlinger diagram came after galactic rotation had been (discovered.)
DeVorkin:— Stromberg worked before Lindblad?
Van de Kamp:Yes. Lindblad actually made use of what Stromberg had found. He said, ďhello, this is what it means,Ē Stromberg didnít get there. It was not because Stromberg was not clever, but he was blocked. It happens all the time in science, that people donít quite get there. And somebody else comes in, in a sense, you see and says ďWhat are they doing? Oh that means, so and so.Ē
DeVorkin:How did you hear about that? Was that an actual association between Stromberg and Lindblad?
Van de Kamp:No. Stromberg published his work in the ASTROPHYSICAL JOURNAL and Mt. Wilson contributions, with all these lovely diagrams, the asymmetry diagram.
DeVorkin:And then Lindblad —
Van de Kamp:— published, yes. Publication in those days was much quicker than it is now. Whatever I present now takes half a year before it appears.
DeVorkin:OK, this is Tape #3, You made a comment about the lag time in publication, being far less in the twenties, and you gave an intimation that this partly was a function of refereeing, How has the system changed, and how do you feel about the changes in the system of refereeing, since the twenties?
Van de Kamp:Well, this is a delicate matter, shall we say, because one always may be accused of being involved oneself, and kicking, which is not necessarily so. But it seems to me, in the so-called ďgood old days,Ē there wasnít refereeing, except via the institution with which one was connected. One might write a paper, and the director of the observatory or of the institute would pass judgment, whether it should be published or not. And if the judgment was favorable, then the paper was sent off to the journal, and it was published. Now, I think that if one looks at journals 50 years ago, I donít think there are that many bad articles in them, that sneaked through. Nowadays, everything is heavily refereed, and it leads to great delays, and to feelings like: ďI have not been treated fairlyĒ or something like that, once in a while.
DeVorkin:Did you have these feelings from time to time?
Van de Kamp:No. My own experience with refereeing has been this. My procedure or attitude, is this way, one should have oneís paper refereed by oneís immediate colleagues, in the institution.
Van de Kamp:Locally, yes, own people. In any case, for example, I show all of my papers to Miss S.L. Lippincott, whoís rather busy, but primarily Hershey, who is a very good reader. He reads my article with — if one can read with a fine tooth comb, so to speak — and lets me have it. At first he was a bit hesitant about it. He said, ďOh well, I shouldnít —Ē I said, ďGo ahead. Nothing is worse than for me to ask advice of somebody.Ē ďWill you please read my paper?Ē I would ask, then he glances through and says. ďThis is wonderful.Ē This is not what Iím interested in. I want criticism. Positive criticism. I donít want nasty criticism. I donít believe in maliciousness.
Van de Kamp:Constructive criticism, exactly. And I get it from him. With the result that my paper is the better for it. And this is mutual. When he writes a paper, he shows it to me, and I have the feeling I criticize him less than he criticizes me, but thatís fine, and the criticism is both, sometimes, of an editorial nature, or even language, and contents, of course, and emphasis. Now, my experience is limited, I must say, as far as my own papers are concerned and what I observe with others, that sometimes a paper is heavily refereed by three or four referees who donít agree, and then one gets some quotations from that, and — well, again, theyíre in oneís field, one knows pretty well who is the referee, because there are not too many people. So one can judge from the style, sometimes from the typewriter even — you donít have to be a great detective for that — who did the refereeing. And this may be helpful. But there are some referees, Iím glad to say, who say; ďI want the writer to know that I refereed this, and I want to play with open cards and Iím writing to him, making suggestions.Ē This, I think, is good. I believe in things being in the open, rather than things being hidden. Now, the refereeing leads undoubtedly to delays. Thereís no doubt about that. Not everybody answers immediately. If I get a paper which Iím supposed to referee, I try to get it out as soon as possible, so that I shall not be the cause of further delay. And I try to be very brief, and I try to be reasonably positive if I can. Always keeping in mind the principle of free speech, so to speak; even if I might not agree with that particular article, I let the person express himself. Itís good to have some tension, some disagreements going on, I think. I have only one quarrel with refereeing, I was invited to write a paper at one time.
Van de Kamp:When? No names and no times mentioned, this time. I was invited to write a paper. A survey paper, you know, that sort of thing. And the survey paper was refereed. Why shouldnít it be? Well, thatís a real question, whether an invited paper should be refereed. I have written a number of invited papers which were not refereed. They were gone over by somebody who picked up a few typing errors, and asked a few questions, which I always welcomed. Fine. A good editor is a good thing. In the old days, if I may interrupt myself, with the ASTRONOMICAL JOURNAL, for example — Dirk Brouwer was a marvelous editor, and I would send a paper to Brouwer and I think that was before the day of passing the buck, thatís what refereeing is — thatís really what it is, to a great extent. Brouwer was able to judge all the papers that came to the ASTRONOMICAL JOURNAL, and he let me have it, once in a while. But it was always on the level, on a very high level. For example, he would point out, ďPeter, you have said this sort of thing before. It takes up space, and subscribers are not interested to read that again, so canít you leave that out?Ē And he was right. He said it in a nice way, in a businesslike way, but it was well-founded. Or, he would make a criticism. At one time I remember he said, ďWell, the masses which you have found here donít agree with the mass-luminosity relation,Ē to which I reacted sort of angrily, ďSince when am I supposed to confirm the mass-luminosity relation?Ē I was younger then than I am now.
DeVorkin:Could you give me a date for this?
Van de Kamp:Oh, well, 30 years ago, perhaps. I mean, Iím supposed to provide material; whether it agrees with anything or not, thatís another matter.
DeVorkin:These were not astrometrical binaries, these were regular —?
Van de Kamp:No, this was a regular conventional old-fashion double star.
Van de Kamp:It was simply that my results probably werenít very accurate. But I still believed that I think the massóluminosity relation should never be considered as anything holy. If somebody finds a discrepancy, then maybe the person is at fault or the material isnít good enough, or could it be real? I donít know. Well, anyway this was all amicably solved. I repeated again, those were the days, when the editor, this particular editor, I should say, Brouwer, who was a very superior person, could really judge things. Now, he may have asked colleagues sometimes, because he was the chief editor, and then there were associate editors. Maybe there were no referees in those days, but just an editor and a few associate editors, and the associate editors were the referees, probably.
DeVorkin:Youíre talking now about the early fifties?
Van de Kamp:Iím talking something like that, 25 years ago roughly speaking.
DeVorkin:I havenít been able to look in that period, but I can say that for the thirties, papers were refereed by people who had familiarity with the field, the general subfield. In the ApJ. I donít know about the A.J.
Van de Kamp:— The ApJ is a much wider field, I think.
DeVorkin:I really donít know the AJ history of refereeing —
Van de Kamp:— The field is so much narrower. Yes. For a long time, Brouwer was the man. He was the one, you see. So, I was at one time invited to write a survey paper, and the person had been after me for a long time to write this paper. I said, ďNo, Iím not ready for it,Ē I used a story about Einstein which Iíll tell later. Iíd say, ďIím not ready for it.Ē Then finally I decided that one never gets really ready for anything, and there is merit in publishing something, because as soon as you have published, then you find out what you should have done, perhaps, and you can start work again, The publication exposes you, and this is good. Well, anyway, I finally decided, ďOK, he can have the article.Ē I said, ďDo you still want it?Ē ďOh yes, I still want it.Ē And I sent it. And then I didnít hear anything for a long time. Then I got a letter back, not from the person but from his secretary, that the paper has been refereed by four different people, and ďIím enclosing two of their opinions. If you will revise your paper drastically, well, we will accept it, we will consider accepting it.Ē
DeVorkin:This was from the secretary of the person who had asked you originally for the paper?
Van de Kamp:Yes. DeVorkin; Again, youíre not naming names or dates?
Van de Kamp:I prefer not to, at this moment because if I would dislike this person (it would be one thing) but this is not the point at all. I think it was stupid of this person not to write me himself. Well, so, thereís only one thing for me to do. I said, ďSend me back the paper. After all, you canít have it, in that case.Ē Well, then, later on I heard from the person himself, the editor in other words, who had invited me, and he said, ďWell, I hope you will see your way clear to revise this paper.Ē So I think this was a very bad treatment of me. Now, Iím not a young graduate student or a young undergraduate student. I like to think that I have a reputation which is fairly good. Iíve published some wrong papers and Iíve made mistakes, like everybody else. But if Iím invited, year after year, to write a paper, and then finally I do it, and then I am asked to revise it drastically — I donít do that.
DeVorkin:What was the nature of the revision that they wanted?
Van de Kamp:I donít remember the details, but it was not that I had written this paper overnight. Well, everything works out for the good, I believe. They couldnít have it, itís quite obvious. I kept the paper for a while, and revised it because I had grown and developed. I extended the paper, and it became a much better and a much longer paper.
DeVorkin:Was this the direction that they wanted?
Van de Kamp:No, this was the direction I wanted to develop. It became a more mature paper. And I presented it to another journal, I should say where it was accepted without further ado. They were both periodicals. Well, all right. Iím not saying that some of the criticism that was contained in these four refereesí reports was not justified.
DeVorkin:Did you know who they were?
Van de Kamp:No. I didnít even try to guess. I can guess, but I didnít want to lose so much time, for detective work here, I would have taken a few suggestions. But I think really, the mistake was a matter of tact or even of choosing words. To revise it drastically, that really (stung).
DeVorkin:The secretary told you this.
Van de Kamp:She may not be an astronomer even, for all I know. But this becomes a matter of manners. If it had been approached in a different way, if the editor had said, ďWell, itís a good try but why donít you try again?Ē or something like that, or ďPerhaps I shouldnít have rushed you, so —Ē
DeVorkin:How long was your manuscript in pages?
Van de Kamp:Oh, in print it would have been 10 pages, I think.
DeVorkin:So this was an extensive effort on your part, and the editor knew this.
Van de Kamp:Yes.
DeVorkin:Now, is this a criticism of the refereeing process, or of an editorial position which you simply donít care for?
Van de Kamp:I think my basic objection here is that this was an invited paper, and I think one accepts invited papers, the way they are. Thatís really the way I feel. The paper has grown to a 20 page paper now, and is a much better paper. If Iíd kept it for three more years, it might have grown even more. But you see, any paper that you keep will change eventually, if you keep it at your desk. I rewrite my things sometimes six or seven times. And finally I say, well, enough is enough, out it goes. But you see, I donít want to send out my first draft, and then later say: ďOh my gosh, Iím sorry I didnít look at that.Ē Now I have the feeling, when I look at my papers and send them out, I can look at them several years later and say, ďWell, itís all right. It was the best I could do at that time. It was a mature, well-thought out paper.Ē
DeVorkin:What about for general publishing in the journals? The refereeing process certainly has changed. Itís gotten more sophisticated, partly with advancing specialization in the field.
Van de Kamp:Yes.
DeVorkin:Do you see any preference for a different structure of refereeing at this point? at this moment? Or, some structure that existed in the past?
Van de Kamp:Well, refereeing may be necessary, I have presented many papers to the ASTRONOMICAL JOURNAL. (When I was talking before, it was obviously not the ASTRONOMICAL JOURNAL). I usually have gotten opinions from referees back, and Iíve always made use of them. They were not opinions that ďthis paper is no goodĒ or ďfor Godís sake, donít publish it.Ē Not that sort of thing at all. They said, ďWell, couldnít you have said — I feel about this — and so on. Things which were normal, which I would expect from my colleagues. And I have made use of some of them, and not made use of others where I disagreed. I am trying to put myself in the position of the uneasy chair of the editor. Itís a hell of a job, in a way. The editor, of course, has the ultimate right, I think, to accept a paper without refereeing, and I think one paper which I presented was immediately accepted, which pleased me and puzzled me. Obviously he didnít have it refereed. He just accepted it.
DeVorkin:Do you remember which paper this was?
Van de Kamp:Yes, it was my last paper on Barnardís Star for the ASTRONOMICAL JOURNAL. I had thought it might go through refereeing, with a few people who donít like my work. But apparently it wasnít even refereed. All right. The paper was carefully prepared, very short. Itís important, I think, one should make oneís papers short. As a general thing, I would agree with almost any referee that papers are too long. ďCanít you say it in fewer words?Ē ďWell, Iíll try.Ē Now, you see, you did say it in fewer words. Therefore, then do it that way. So that is one thing. But donít you think that in general it could be this way: That an editor is burdened with so many papers so he passes them on to other people. In a certain field, in the field of astrometry, for example, there are not too many people who can do this. And we know, always, when our papers are refereed — ďOh well, Strand thinks this, and so and so thinks that, and this obviously is so and so.Ē Well, thereís nothing wrong with that. There are few people in the field. The people in the field of course support each other, to some extent. Itís an interesting human aspect, the old story: We have to hang together, you know, otherwise weíll hang separately. But also, within a certain field, there are a few who want to find fault. Sometimes deliberately.
DeVorkin:Any that you could particularly identify?
Van de Kamp:Oh no, I donít want to mentioned names at the moment, I think. After maybe a drink I might, but not now. Among my colleagues these things are well known. But, it is too bad, if personalities enter in the refereeing. And they do enter, sometimes. And they come from people whom I call unhappy people. People who are happy are positive, and their refereeing, even if they donít like a paper is positive criticism. But others are unhappy, and thatís another matter. In connection with this, I think of something else. I think of good old Henry Norris Russell again. Now, in the old days, (when I say the old days, I mean, 30, 40 years ago) at the meetings of the American Astronomical Society, there were always three outstanding people. There were Shapley, Schlesinger and Russell. They were sometimes referred to as ďthe Generals.Ē They ran astronomy, in a way. Their opinion was very important; when it came to appointments and that sort of thing, they were consulted. Iíve noticed, several times a young person, an unknown person, would come and present a paper, and the paper sometimes was good, sometimes not so good. I donít recall any real bad papers having been presented. I think there was sufficient internal screening by the director of the observatory and by the person himself. People were very careful in the past before they would present a paper, generally speaking. And then, when it came up for discussion, there was always one person — I have referred to this in a publication, this is printed somewhere, I feel Iím repeating myself now — there was always one person who had an opinion, and that was Henry Norris Russell.
DeVorkin:We spoke about this last week.
Van de Kamp:Yes. He was probably the best informed of all astronomers. He knew. He had read everything and understood everything, and he often understood better than the person himself what his paper might mean, and he would comment, in a very positive way. And if the paper had not been too clear, which could easily be, he would make it clear to the audience, without making the author feel that he had done a bad job.
DeVorkin:Was he sensitive to this?
Van de Kamp:Oh yes. He was quite sensitive to that, yes. And I always remember, that was one of the very positive things about Henry Norris Russell, who otherwise appeared to be a very unapproachable person. Not easy to talk with, but always this positive approach, encouraging young people. I think I mentioned also that the counterpart to that, later on became, for a while at least, Martin Schwarzschild. I havenít been at many meetings. But Iíve been at a number of meetings where somebody presented a paper, some young person and by this time Martin Schwarzschild had taken the place of Russell, you might say. But probably, there are more papers which are slept through, because of more people and all that, and if there are more people, there are more good people and also more bad people. And then Schwarzschild had this very nice approach. His charming English was very good, with a fairly strong accent. He would say, ďWell, I probably am very dumb, but I did not understand what the speaker said. Did he meanÖĒ and then he would say so and so, and explain. But this introduction, ďI am probably very dumb,Ē you see, heíd thrown that in and then putting it, in the form of a question, disarm the speaker completely that way.
DeVorkin:What was the audience reaction to this?
Van de Kamp:Oh, it was good. I mean, Schwarzschild was much more charming about it, much more theatrical. Russell wasnít. But Russell was the referee, if ever there was a referee.
DeVorkin:Could we possibly expand on Russellís personality in this regard? There was never any question of his sincerity, to the growth of the field, I take it. He was never after any people.
Van de Kamp:No. I donít think so.
DeVorkin:Did you ever experience any event where Russell fully disagreed with something that had been said, and spoke his mind?
Van de Kamp:I donít remember at the moment, but Iím sure that must have happened, because I think he was a man of the highest integrity, and sincere, and if somebody had done some things which were either foolish or which he didnít agree with, he would say so.
DeVorkin:What if someone criticized him?
Van de Kamp:I donít recall that it ever happened. He was not very vulnerable. He did good things, had done good things always. Speaking of Shapley — Shapley was vulnerable, I think, at times. He did so many things. He was, in a lovable way, a bit wild. And Shapley and Schilt didnít get along. I donít know the details right now, but it had something to do with Cepheids, and probably it was a hangover from the Old Kapteyn days, when Shapley was still being attacked scientifically for, my gosh, building a whole universe on a couple of Cepheids. And I remember, at one meeting, I donít know the details, but Shapley had held forth on something and I was rather shocked that Schilt asked him a question which, was very tactless, really. (But) Very sincere. He said, ďWell, enough about that, thatís no good,Ē or something like that, and then Shapley said something like this, I canít remember the exact words — it was all in the discussion, open discussion — ďWell, but after all, there are these and these — (referring to different points). The Schilt said, ďWell, if it hadnít been for that, all this would have been no good whatsoever.Ē He sat down again. This happened more than once, that Schilt attacked Shapley in a most tactless way, and Shapley handled it. Shapley didnít get mad — he wasnít that sort of person — but it was held against Schilt, after all. Iím sure that Shapley was a sensitive soul, and so was my good friend Schilt. But these were some of the more serious confrontations I remember, between Schilt and Shapley.
DeVorkin:Was this before Shapley was in retirement?
Van de Kamp:Oh, yes, this was all in the thirties or thereabout, when Shapley was young and Schilt was young. Schilt had some disappointments in life. I know that.
DeVorkin:These were personal or professional?
Van de Kamp:Well, professional. Not personal. He was happily married and all that. And he had a good career. He became professor at Columbia at a fairly young age. Schlesinger thought very highly of Schilt, and as a matter of fact, considered Schilt as a possible successor. I think Brouwer turned out to be a good choice, in that respect.
DeVorkin:To your knowledge, did Schlesinger choose Brouwer personally as his own successor?
Van de Kamp:Oh, I think so. Things were done in a rather personal way, not all this business of committees and so on. You knew a good man when you saw him. Well, it wasnít quite that way. I know, about the succession here, when they looked for a successor for Miller, I told you that, they had a whole list of people. I have a list somewhere here.
DeVorkin:We havenít actually gotten to that point yet, in our discussion.
Van de Kamp:No. It can wait.
DeVorkin:In fact, we should go back to the twenties. And finish up your early interests in galactic structure, and how you felt eventually when other people apparently re-did your work, or extended your work, on the existence of absorption in space. This would take us into the thirties, during your time at McCormick.
Van de Kamp:
The work at McCormick with Vyssotsky was obviously a long range work, and it lasted for a long time, and ended up with Publication No. 7 of McCormick Observatory, and then after that Vyssotsky and his wife continued, and it became publication No. 10. Incidentally Mrs. Vyssotsky was Emma Williams. She played a very important role in all this work. Emma Williams Vyssotsky. I was recently approached by the author of ďNotable Women in AstronomyĒ, Barbara Sicherman, who deals with notable women as such, I think. They came up with a list from which to choose about ten or so. My top choice was Emma Williams Vyssotsky, as being the most distinguished of all, although a lot of the work she did was behind the screen. But Vyssotsky and I benefited enormously from that. And then the next most important one, I thought, was Louise F. Jenkins primarily through her contained association with Brouwer and the Yale Parallax Catalogue. Emma Williams was a Swarthmore graduate, by the way. Emma Williams was much the greater scholar, thereís no doubt about that. Louise Jenkins, I would not call a great scholar in that sense. But she played a very important role, of course, at the Yale Observatory. These were astronomers who died between Ď50 and í75.
There are some very good women running around yet, but they donít quality for this. They will be taken care of in 2000 if they die before 2000. So, so much for Emma Vyssotsky there. Well, I became interested in this absorption business through Trumperís articles. I said, ďMy gosh, this is interesting — something can be done because there are lots of star colors lying around that havenít been analyzed.Ē I analyzed them, and summarized all of this in that first article which I sent you a copy of, I believe, in the ASTRONOMICAL JOURNAL, which was published without refereeing, obviously, and which had a bibliography of about 30 articles that had been written up to that time on the absorption of light in space. Oort at one time referred to that as being a complete bibliography up to that day. By now, there are probably 5000 articles on the subject. Itís hopeless. Well, then I followed this up by taking Shapleyís globular clusters and bringing them closer to home, and there I used a system which I was the first to utilize — to use galaxies as they appeared in the catalogue by Shapley and Ames — to derive the optical thickness of what was called in those days the galactic absorbing layer. I also used some other material, but basically it was the Shapley-Ames material. And that was the first determination of the optical thickness of that absorbing layer. Then I used that to reduce the distance of the globular clusters, in bringing them closer to home. And that was basically all I did in the field.
DeVorkin:This was 1930?
Van de Kamp:1930-1932 and 1933. Then I stopped working on that. Then other people had become interested in it, like Hubble and Stebbins. They probably got much better material than I had.
DeVorkin:I would see Hubbleís immediate interest in the possible revision of the Hubble Constant, because you were revising the size of the galaxy.
Van de Kamp:Yes.
DeVorkin:And then the Cepheid calibration. Did you ever talk to Hubble or others about this?
Van de Kamp:No, I never talked much with Hubble. He died rather young, didnít he? He was rather unapproachable anyway.
DeVorkin:Did you have ideas personally about the cosmological significance of what you were doing?
Van de Kamp:None whatsoever. I was just interested in straightening out the globular clusters and bringing them closer to home. I reported on that in 1932. In 1932, there was a meeting of the International Union. (IAU)
DeVorkin:The one that you have the picture on the wall?
Van de Kamp:Yep. And immediately after that meeting, there also was an eclipse, as you may know, in September.
DeVorkin:Oh no, I didnít.
Van de Kamp:In Canada. And so this brought astronomers from the world over. Now, what Iím going to mention now does not appear anywhere. Shortly after this IAU meeting, Shapley organized a meeting on galactic structure, and there is no record of it anywhere in the literature. Hardly. Thereís a minimum of reference to it, in POPULAR ASTRONOMY, possibly. Whatever there is, I have gathered that there isnít very much.
DeVorkin:Is this one of the Harvard Colloquia that were held?
Van de Kamp:It was an informal Harvard meeting on galactic structure.
Van de Kamp:In 1932, right after this IAU meeting. It was not recorded. There was a program. And I was invited to speak. Shapley had planned to invite Trumpler, but Trumpler couldnít come. So Shapley invited me to give a paper, which was very thoughtful of him, My report was the first public report, as far as I know, on bringing the globular clusters closer to home, and showing that they formed what later was called ďa halo.Ē I didnít think of that word. I called it a ďsuper (globular) clusterĒ of globular clusters, And I had drawn slides of their distribution and of the fuzzy objects near the Andromeda galaxy discovered by Hubble and tentatively identified as globular clusters in 1932. And I showed that it looks very much the same. Thereís agreement there. But those particular results were never published. But then of course my globular cluster (papers were).
DeVorkin:Was this a surprise for Shapley, when you gave this paper?
Van de Kamp:I donít remember now. I think it was. All these things were so much in the air somehow. I felt slightly guilty, here I took Shapleyís watermelon distribution and made it a regular melon distribution. Shapley accepted that. It did not do anything to his great discovery. It was simply a touching up, isnít it? Reducing distance from 12 kiloparsecs to 5Ĺ kiloparsecs. But the general picture of the galactocentric system remained, of course. But itís too bad — I wrote to Shapley about that — that there is no record of this anywhere, except I think a remark somewhere that after the meeting a conference was held. There were good people there. I was among very good people. A.S. Eddington was there.
DeVorkin:Eddington was there?
Van de Kamp:Oh, all kinds of good people.
DeVorkin:Did he come from the particular IAU meeting?
Van de Kamp:Probably just stayed on, you see. The IAU meeting was held in Cambridge, and this thing afterwards was also held in Cambridge.
DeVorkin:Did you talk to Eddington about this directly. Did he have any comments?
Van de Kamp:No. Nobody talked to Eddington.
DeVorkin:Nobody talked to Eddington?
Van de Kamp:He always walked around, like that — (gesturing)
DeVorkin:He was solitary?
Van de Kamp:During this IAU meeting, there was an excursion, a boat trip to Plymouth, Massachusetts. And all 400 astronomers were loaded on that, and there was considerable conversation — if this boat would sink, now, think of all the positions that would be open! But anyway, then we ended up in Plymouth, and there we ate. There were two food lines, chicken on the left and lobster on the right, or something like that. But at any rate, on board ship, as would happen, there was a piano. By that time my reputation had been ruined anyway, that I was a pianist, for all the people to dance or drink to — but this was before Prohibition had ended, so there was no drinking — Prohibition ended in Ď33, but this was still a dry situation. Thatís why everybody looks so woeful on the group photograph. But anyway, I played the piano, and I looked around, and there was Eddington sitting next to the piano, and I was playing jazz music, and I wondered what must this man think of me? He probably didnít even hear it. He was always involved with something else. I had a similar experience, but that was on a much easier level, in 1955, there was a meeting in Bloomington, and we had a get together afterwards, at somebodyís house. It was a conference on stellar atmospheres, I was with the N.S.F. at that time — thatís why I went to that meeting. And there, Marshall Wruble and I sat down and had a jam session at the piano. And who was sitting there, where Eddington used to sit, so to speak, in my memory? Otto Struve. But he accepted it. Otto Struve accepted it.
DeVorkin:There was a piano at Lick, at least when I was there. Was it in your day?
Van de Kamp:Yes.
DeVorkin:Did you play?
Van de Kamp:Yes, I played. Sometimes.
DeVorkin:Any of the other Lick astronomers play?
Van de Kamp:We had regular musical evenings at Lick, — Radio had just been invented. The first time I saw a radio was at Lick. And an electric ice box, which was very complicated.
DeVorkin:It seems from your published record that after your return to McCormick, after Lick, you began broadening out into many different fields of interest, all bordering on astrometry and the galactic distribution and motion of stars.
Van de Kamp:Yes.
DeVorkin:What got you interested in double star work?
Van de Kamp:Well, letís see, now. You see, we were doing this galactic structure work which would be published five years later or something like that, and one had to do something else in between, to preserve oneís sanity, with this long range program.
Van de Kamp:Well, yes, with Vyssotsky. It was nice work. It was a happy group of two people. But we knew that, actually, it was not until Ď37 that the first publication came out. Some meanwhile, — if I can analyze it or remember correctly — after all, there was parallax work going on at the observatory, and I saw that, of course, there was a possibility of doing mass ratios. And I did my first mass ratio of Zeta Herculis, in 1934. This I just sneaked in. And since I felt that this was extracurricular, almost, as compared with galactic structure project, I would come in 8 oíclock in the morning and measure a few plates before the regular work started. I wouldnít want to have Vyssotsky feel that Iím not doing my duty toward the general work. So I published this mass-ratio and it was in the air, that after parallaxes, mass ratios would follow. And at Sproul they had gone in for that, also.
DeVorkin:Was K. Strand there at that time?
Van de Kamp:No, Strand didnít come until I came to Sproul, a year after I came, but Pitman and Kovalenko were doing mass ratio work, and it was done — looking back — in a very elementary and provisional way. But they were doing it. That was important. Then when I came to Sproul I certainly went in for the mass ratio work. (There were) more years (available as a base line) — this is important — but I also went in for the search for unseen companions of single stars.
DeVorkin:By 1935, at least, you had begun paying attention to Barnardís Star?
Van de Kamp:No, not Star. That didnít come until I got here (Sproul) in Ď37. Oh yes, Barnardís Star, at McCormick I had made an examination of the secular acceleration.
DeVorkin:Thatís exactly right.
Van de Kamp:Yes. That was another problem which was very provisional and which of course was superseded again later; by now that is well determined. As a matter of fact, this whole matter of secular acceleration has always been on my mind, and I have just written a long survey article. It will be published in VISTAS. (Without referee. I think.)
DeVorkin:Well, I donít want to ask about Arthur Beer just yet, but I imagine he is a very popular editor with you and with others.
Van de Kamp:With everyone, I think. Well, Arthur Beer is his own editor. Which is important. Heís a good man. I donít think he would accept a paper from me if it werenít good.
DeVorkin:The beginnings of your search for unseen companions of stars, then, really started at Sproul. Is this because you had the freedom, of director?
Van de Kamp:
I had the freedom. But it started before that. It started at McCormick, where Vyssotsky and I discussed that. We realized that the Bessel discoveries were comparatively easy, and that nobody had done anything about it, except for a few discoveries of third companions in double star systems. As so we decided, it would be nice to repeat parallax series, for the purpose of discovering unseen companions. Mitchell of the McCormick Observatory was not particularly in favor of that, but that was understandable. But then I think, a historically very important thing happened. Vyssotsky and I wanted to put faint stars on the program, Mitchell wanted bright stars. Bright stars are easier, but most bright stars have no parallaxes to speak of. And here were all these new discoveries of faint proper motion stars by Ross. This was before W. Luyten really entered the field. All these faint Ross stars. And so Mitchell said, ďOK, you can put some on the program, but no Ross star fainter than the 11th magnitude, and they must have a proper motion of at least one second of arc.Ē Which, from a directorial point of view, was not a bad thing. You have to draw the line somewhere.
So we put a lot of these Ross stars on the program. And they were measured up for parallax in a few years. This was our idea, to get parallaxes of nearby stars. For Ross 614 instead of the series being finished in two years, it dragged on for nine years, because of what I call directorial sabotage. The star were regularly removed from the program, so instead of getting this parallax series in two years, we had to wait nine years to get the parallax. This was a blessing, because in nine years Ross showed a perturbation. I still remember when it happened. D. Reuijl, who by the way was my first cousin — you saw pictures of him as a child upstairs said, ďLook here, 25 plates, look at these residuals, pulses, minuses, pulses — wonderful, perturbation.Ē We measured declination immediately, because normally parallaxes were measured in right ascension only. We measured declination and it was even worse, or rather even more beautiful. Terrific amplitude! Obviously the first photographic perturbation. That was published. A period of nine years was derived because we just tied the ends together and made it nine years. Later on it turned out to be 16 years.
DeVorkin:How did you feel about this?
Van de Kamp:Well, we felt that we were on the right track, that itís possible to discover (perturbations). We had, a bit, a snooty feeling. Oh well, we knew this would happen sooner or later. But the very interesting thing is that the star sneaked into the program, because its magnitude was very bad and provisional. By Ross, it was 10.9 though it turned out to be fainter than the 11th later on. The proper motion by Ross was 1.Ē 01. Just made it. The proper motion later turned out to be 99/l00th! Now, you wonder how many stars are not in programs yet, and are just waiting to be measured for parallax, and/or, more important, for perturbation. Now, the parallax of this star was not super large. It was 25/100th of a second of arc. But the period was long enough to show a good perturbation, and the companion object was not a planet but was a regular faint M dwarf, that swung the bright star around.
DeVorkin:By the mid-thirties at least, people had been wondering what the difference was between stars and planets.
Van de Kamp:H. N. Russell wrote a good article on that.
DeVorkin:And he said, about 5/l00ths of a solar mass, which is actually very close to the Kumar limit.
Van de Kamp:Yes, or 6/100.
DeVorkin:Yes. Did you think that there was a possibility at that time of actually measuring down to that very low mass?
Van de Kamp:Yes, I think so. I did not think seriously about going way beyond that, to planetary levels. But Ross 614 was a terrific encouragement for the whole field, you might say. And when I came here, I felt justified in spending half of the time at the telescope on single stars, for the purposes of studying perturbations.
DeVorkin:How many stars on your list were originally selected from from the Ross material.
Van de Kamp:At McCormick?
Van de Kamp:Oh, I donít know, but several dozen sure. But I donít know exactly. Iíve never been very good at that sort of thing. But here, as you know, of course, we have been at this for 40 years now. At Sproul we have found I guess well over ten perturbations. McCormick has found one or two. And of course, K. Strand has found about six now, with his new telescope. And why? Because he has a beautiful telescope, and measuring machine and, although ten years isnít very much — very high accuracy in both telescope and the measuring machine. He has found several perturbations with period of a few years only, John Hershey and Sarah Lee Lippincott can tell you more about that. Ross 614 turned out to be 16 years, and itís well determined now.
DeVorkin:The companion has been observed now, has it not?
Van de Kamp:The companion was observed by W. Baade, Ď55, and has been observed by others since.
DeVorkin:How did you feel when he made the confirmation?
Van de Kamp:Oh, ďI told you so,Ē — that feeling again, which is nice, anyway. Itís one of these things, ďI told you so,Ē but once you can see the thing, itís fine.
DeVorkin:Did he write you directly or did you talk — did he telephone?
Van de Kamp:No, he wrote. One didnít telephone in those days. He wrote that he had observed it, after having tried for three nights with poor seeing, and then the fourth night he got it. And he took a photograph also. And since then it has been photographed. It has been seen by Charles Worley, by G. van Biesbroek and by some others. Itís not an easy object of course. This is of some interest, because there is a debatable observation in the literature by van den Bos, who saw Ross 614 as a double, and this was ignored. I donít have the information in my head right here. A number of the important perturbations have been found by N. Wagman at Allegheny. You see, Allegheny has a great plate collection, a beautiful telescope, and Wagman discovered several perturbations. Thatís a great credit to him. One is of Alpha Ophiuchi, which was confirmed by us here. Another, Mu Cassiopeii, was also confirmed by us here. And then, Ross 52, which also has been confirmed at Sproul. So thatís a real contribution by Allegheny Observatory.
DeVorkin:What about Luyten L726-8?
Van de Kamp:Thatís a double, yes.
DeVorkin:Was that also an unseen astrometric binary?
Van de Kamp:No. That started as a double. It really started as a proper motion star. Then people put it on the program at McCormick and at Yerkes, and saw that it was double, on the plate. W. Luyten couldnít have seen it, because his scale was too small. This has happened several times. This is the same with Ross 52, which still can hardly be seen as a double, but was discovered as a slightly elongated object, at McCormick.
DeVorkin:Letís go back to the mid-thirties again. As you were working on these binary systems, how did you feel about the revival by Lyttleton in the mid-thirties of the collision theory, for the origin of solar systems? And its possible effect for your searches and for your ideas?
Van de Kamp:I never paid much attention to that. This whole idea of the origin of the solar system, I consider fairly well settled by now. (Through C. von Weizsacker and C. Kuiperís research).
DeVorkin:But in the thirties, how did you feel about it then?
Van de Kamp:I donít recall having any particular feelings about that at the time.
DeVorkin:Russell of course was involved deeply. He criticized the Lyttleton revision, and then Spitzer came along, 1939-40, showing that these filaments could not condense.
Van de Kamp:Yes, I know.
DeVorkin:You donít recall any of your feelings about this general line?
Van de Kamp:I still remember, Russell gave a series of lectures in 1935, at the University of Virginia.
DeVorkin:On the solar system.
Van de Kamp:And there he came up with what seemed to be a new idea, that originally the sun was a double star. And then something happened to the one star, and now we have the planets. But I think collisions are out, really. Chances of collision are nil. You canít explain origins that way. You could explain one system, perhaps, the solar system for example, but itís farfetched.
DeVorkin:Iím really interested though in how you felt in the thirties, if you can recall your feelings then.
Van de Kamp:As Russell pointed out, it became gradually evident that there were many double stars, and the sun may have been a double star too, at one time. Why is the sun a single star? Maybe it was a double star, and then the one star was destroyed, and whatís left are the planets. I donít recall if he went into deep scientific explanations. These were popular lectures, mind you, which he gave. The Page-Barbour Lectures, I think they were called.
DeVorkin:Iíve read parts of that book, the book that came out of that. And it seems as though he never really considered that idea finally in print. At least, he would always remain critical of the collision hypothesis.
Van de Kamp:Yes.
DeVorkin:But he wasnít really talking about collision, he was talking about the disruption of one sun, is it so?
Van de Kamp:Yes, but wasnít that also supposed to be due to a collision with another star? I think so.
DeVorkin:Had everybody given up on the collision or the encounter theory from the probability standpoint?
Van de Kamp:Yes.
DeVorkin:Did you have any feelings about the probability argument, in the thirties, alone; just the probability argument?
Van de Kamp:I donít know. Speaking for myself, I didnít give much thought to that. But perhaps my reaction is the same as that of W. de Sitter, who gave lectures in this country in the early thirties. He gave a wonderful series of lectures at Harvard, that appeared in a book in Cosmos. De Sitter was invited to give a lecture, I think in New York, probably at the Planetarium or the museum, and he gave a lecture on the Milky Way system. 1932-33, thereabouts.
DeVorkin:That was about when the Planetarium opened.
Van de Kamp:Yes, it was — Iím not even sure it was there. It must have been there. Those were the days when there were lots of cranks in the audience. We donít have so many cranks nowadays, it seems to me. People are much better educated. Unless you call people cranks who want to know all about black holes and UFOís. Well anyway, some crank, a real crank, apparently got up and said, ďDr. de Sitter, what do you think about the expanding universe?Ē And apparently de Sitter made it clear that he didnít want to talk about the expanding universe. And he stood up with his six feet, six inches, he was a very tall man, and said, ďI donít think about it.Ē
DeVorkin:Why do you think he didnít think about it?
Van de Kamp:Aw, he wanted to get rid of this fellow.
DeVorkin:But what do you think de Sitterís feelings were about all this?
Van de Kamp:Oh, he worked himself on this problem as you know. I donít know. I think he was just annoyed by the way this man proposed the problem. Thatís my one story about de Sitter.
DeVorkin:Thereís one aspect of your early life that we have not covered. Weíve covered music, and development of your own life and of the life in general, to a certain extent, in the Netherlands, but of your religious background, we havenít spoken.
Van de Kamp:
Well, letís start at the end. Now I am a free man. I mean, I deal directly with the good Lord, at this stage of my life. But having been brought up in Holland, my parents were what in Holland is called ďLiberal ReformedĒ, in other words, Protestant Dutch Reformed, but ďLiberalĒ Reformed. Holland is a country which is split and split and split into groups and more groups, and the old fashioned Orthodox Reformed religion, to which many of my relatives belonged; people who go to church three times on Sunday, and then sin during the week, and then go again three times on Sunday, and so on. My father and mother both were liberal in the best sense of the word, and they were religious also. It was just what one did — one belonged to a religion. Which meant that as children, we were sent to Sunday School, with a penny, which we had to ďgive to the ladyĒ who ran the Sunday School; we enjoyed it, after all, there was nothing else. There was no TV. There was no radio. You couldnít sin in any way. We went to Sunday School.
We heard these lovely stories about the old Testament, and if you want excitement and murder and violence and all that, thereís no better place than the Old Testament, as one after the other is disposed of. Well, Iím not saying that this was our primary interest, but I mention this. So then as teenagers, we went to what we called Catechesaties which met on Wednesday evenings. We went to a small auditorium or small room, in fact, of a building, which probably belonged to the church. There, quite informally with the local preacher, six boys (girls apparently didnít require any education, or maybe they were kept separate, I donít know), learned mostly about the New Testament. And this was in a seminar style. This was very interesting, and very advanced, I would say. And of course, an additional attraction was that it was in the evening, so (when) we were let out, we could do mischief before and after, on the way there and on the way back, which of course was very minor — ringing doorbells and running away; hitting a window and dropping a bottle which broke and so on, that sort of thing, to scare people. My father played the organ in the church so I frequently went with him.
That was his contribution to the church. He didnít get paid for that. It was only when I came to this country that I realized, one gets paid for everything, including being a good Christian. But my father did it for years. At the end of the year, they would give him a book or something like that. He enjoyed it. He played very well. He improvised very well. And I went frequently with him, and I was permitted to pump the organ, once in a while. But when the time came that it was suggested that I should join the church, I was stubborn. I said, ďI donít want to,Ē and I never did. So Iím a free person.
DeVorkin:Did you have specific reasons at that time?
Van de Kamp:I just didnít want to belong to an organization, thatís all. I wanted to be alone, I didnít believe in belonging to organized religion.
DeVorkin:How old were you then?
Van de Kamp:
Oh, 16 thereabouts. I think it was partly stubbornness, because it was suggested that I should do it, and I didnít do it. But my parents didnít mind. My wife Olga, if I may bring that in for a moment, was born in Bavaria where everybody was Catholic, and she was actually brought up in a convent, with sisters and all that. She ran away from that. She didnít want it. She became independent at the age of 16. But when she came to Swarthmore, she joined the Quakers, and became a Quaker. I have frequently been asked to join the Quakers, and Iím sympathetic with the Quakers, but I feel that Iím in a stronger position in life by not joining any organization. Though I do things for the Quakers. I have given money to the Quakers. Itís the only organization I give money to. I distrust organizations, charitable organizations, because so much money goes to the organization. But the Quakers are a little better in that respect, perhaps, I trust.
Well, now my attitude toward religion. Iím awfully glad or very glad, that my parents sent me to Sunday School for years, and to (?), because now I know my Bible, and I think the Bible is wonderful stuff. I quote from it, left and right, all the time. I donít know what I would do without the Bible and Shakespeare, and a few other things like, what is it, ďArchie and Mehitabel,Ē you know, that wonderful book by Don Marquis. And as a matter of fact, in that article, which is bound to appear, may have appeared already, on Barnardís star, the idea of unseen companions and all that, I have an illustration of a Rembrandt etching, ďJesus and the Apostles,Ē in particular Mr. Thomas who didnít believe, you know, unless you could touch. I refer to that, the Gospel of St. John, 20th chapter, 29th verse — you might look that up. Borrow a Bible from your neighbor and find out about that. As a matter of fact, I saw the original etching, I went to Amsterdam specifically to the museum to see that etching of Rembrandt. I always thought of buying one, but there are about six in the world, and the last one changed hands at the price of $20,000 or so. But I got a wonderful photograph, for one dollar, I think.
DeVorkin:What is the imagery and the association with the Rembrandt and the quotation of the Bible, in this work on Barnardís Star?
Van de Kamp:Well, Jesus says, ďBlessed are those who have not seen but yet have believed.Ē
DeVorkin:Itís sort of an answer to the positivist philosophy?
Van de Kamp:Well, I mean, this is interesting for this whole unseen business, of course. We talk about the companion of Ross 614, which has been seen, and other ones; the companion of VW discovered recently by John L. Hershey, and also seen afterwards. Now, there are people who just a priori believe in things which they havenít seen. Well, itís understandable. Itís nice to be able to see a thing. But the law of gravitation is rather reliable. And the law of gravitation has showed us, at least four times now, that it has ďseen,Ē before the eye has seen. So you have to have some faith, and keep your fingers crossed. Naturally itís a relief if, after you have predicted an unseen thing, finally you see it. But in some cases, you can predict that the chances for seeing it are pretty bad. With present day technologies. Especially when you get down to the planetary level.
DeVorkin:Well, how do you feel about technology which will soon be available with the space telescope? Are you involved at all in the possibility of detected 22nd and 23rd magnitude objects around nearby stars?
Van de Kamp:No, Iím not involved. On Monday, as a matter of fact, this coming Monday, thereís a meeting in Washington asking people for ideas of what they might like to do with the space telescope. My former student Nancy Grade Roman is involved in this, as you know. John Hershey is going Monday, and I hope Miss Lippincott is going also, Iím not going. I hope Miss Lippincott will. She should go because we are working in this field of unseen companions, and we should remain informed about what goes on, with these big telescopes. And I will certainly urge her to go. And John will drive, in his beautiful car, have you seen his car.
DeVorkin:Yes, he referred to it as his ďold clunker.Ē
Van de Kamp:Well, he has two cars. He has an old Ford, ready to break down, and then he has a Cadillac Eldorado.
DeVorkin:Thatís the one he was referring to as the old clunker.
Van de Kamp:— that he bought for a ďfew penniesĒ and then renovated completely, a lovely car. Thatís the kind of man he is. Getting back to religion, I hope Iím still acceptable. As I say, I feel sorry for so many young people nowadays, who donít get any religious education at all. This is not because I want them to become hypocrites, like so many religious people, but itís part of the heritage and knowledge. One may not feel that the Bible is the final answer to everything, it may not even be well written for all I know, but thereís a lot of good stuff in there.
DeVorkin:Thatís certainly true. The paper that youíre talking about, on Barnardís Star now, truly fascinates me, especially in your allusions to these statements. Are you making serious statements, or just trying to prod people to understand your position?
Van de Kamp:No, Iím quoting. Iím having several quotations in that article, and itís supposed to be out already, but I havenít seen it yet. The British are notoriously slow. My paper which I presented almost two years ago now in Herstmonceaux hasnít come out yet. Gosh. ďUnseen companions. At least I havenít seen it. And thereís always another delayed year, of course, when things lie in the library. They sit there for weeks, with all the unnecessary (paper work in processing.)
DeVorkin:Beer doesnít send complimentary copies?
Van de Kamp:Oh, Iím sure he will, and we shall have reprints, as a matter of fact. But that takes long, too. By surface mail things take an awful long time. See, before the invention of the airplane, surface mail took ten days. Now it takes four or five weeks if you are lucky.
DeVorkin:But getting back to the paper, how do you feel today about present work on Barnardís Star, and your hopes for future work on Barnardís Star?
Van de Kamp:Where are we now, the 1930ís or 1940ís?
DeVorkin:Well, Iím interested in the paper now thatís coining out.
Van de Kamp:As I was saying, there are several quotations in there. One is the famous quotation by Kapteyn about how sad it is that we have to deal with systematic errors, and I deal a great deal with systematic errors. I know better than anybody else, especially my critics. And then I quote from Eddington, something which I donít remember at the moment, and I quote from Ira and George Gershwin. ďIím biding my time, cause thatís the kinda guy I am.Ē
DeVorkin:This is a letter from Ira Gershwin.
Van de Kamp:Yes, heís a lovely person. I visited him in his house and Iíve played Gershwinís piano. Ira is a lovely man.
DeVorkin:We were talking about Barnardís Star. In fact, Iím interested in your present day feelings about the reactions of the astronomical community to your work on Barnardís Star, and you can present it to me as you wish, either presently or historically.
Van de Kamp:Well, I think, if I would have to judge the present opinion of the astronomical community I would say, a ďwait and seeĒ attitude. In a sense, thatís mine too. Now, I announced the perturbation in Ď63, and I interpreted it in a certain way, and I think everybody believed it. I myself wasnít skeptical, but I felt, ďkeep on going, keep on going.Ē You see I waited seven years actually before I announced it, because I didnít want to rush into things. And then in Ď69 I made another orbital analysis. Meanwhile, two other astronomers from a limited number of plates, scattered over two telescopes and over years, here and there, had tried, as they told me, to confirm what I had found, and they were not successful. Of course they hardly could be successful, because they didnít have enough material. And they published an article under the very honest title of ďAn Unsuccessful Attempt toÖĒ But then they turned it around. Since it was unsuccessful I was wrong. This is the impression which one of them tried to create unfortunately. This upset a lot of people. It upset me. But I had no quarrel with their first article, where they couldnít confirm because they didnít have enough material. Itís quite obvious, And as I state in my recent article which if anybody is going to confirm of disconfirm, it looks as if I will have to do it myself. Because I have 4000 plates to start with. They had about 200, I think — not enough.
DeVorkin:You re-measured the plates?
Van de Kamp:They are all measured on the Grant machine.
DeVorkin:The new two-dimensional Grant?
Van de Kamp:Oh yes. All remeasured.
DeVorkin:Are you still using your modified dependences method? For reduction?
Van de Kamp:That plays no role, what reduction you use. There are people who say that Van de Kamp is wrong because he uses dependences. This is stupid, because there is no difference between dependences and linear plate reductions. They are literally identical. In the old days we used dependences because it was cheaper. Now we donít use dependences because the plate constants are cheaper.
DeVorkin:Itís quite evident that you are working with the dependence method with the feeling that there was a way to detect systematic error, second order error. How successful do you feel you were?
Van de Kamp:Second order, what do you mean?
DeVorkin:Well, second order would be something other than tilt of the plate or something like that.
Van de Kamp:Well, the dependence method, of course, and the linear plate constants method, deal only with origin, scale and orientation. Now, the plate tilt is not important here. Itís very small. We know, we can easily prove that. What one has to be afraid of is, of course, optical distortions. What happened in our case was that between 1942 and 1949 there is an instrumental error which must be recognized and allowed for. In 1949 we got a new cell. We replaced the old aluminum cell. And since 1949 things have been (whistle) just lovely. So we have 28 years of constant performance of the telescope which is absolutely unbelievably good. You talk to John Hershey about it. He works on this problem all the time, and heís probably the most knowledgeable person in the field. Recently, for Van Maanenís star he has made reductions, incidentally, with three reference stars, with ten reference stars. People donít believe that, but now we have the proof, if that were necessary, that ten reference stars donít give any better information than three reference stars, because all the error is essentially in the central star. All right, you get a 1 percent improvement, 2 percent improvement. If there were second order terms, color effects and magnitude effects, well, you need an awful lot of reference stars, and I have nothing against it, if people want to do it that way. But that has not been done yet, I think. Now, what the people who criticize me have done, they have used six reference stars. Six or seven reference stars, and they have made a point of trying to point out that I may be wrong, because I use dependences. This is silly. It shows they donít know what dependences mean.
DeVorkin:Did you have a method for accounting for the unknown proper motions of your standard stars?
Van de Kamp:Thatís not important at all.
DeVorkin:Even over a long period of time?
Van de Kamp:No. Well, it introduces a quadratic effect and that I have allowed for. Whether you know the proper motions or not doesnít matter. The perturbation of Barnardís star could not possibly be affected by the proper motion of reference stars.
DeVorkin:What about a change of scale?
Van de Kamp:Thatís also negligible. Thatís taken care of by the reduction method. This is what the articleís about. It may be appeared already. ďThe Sexagintennial Report.Ē
DeVorkin:No, I didnít see this one.
Van de Kamp:It should be out any moment. Yes, it has appeared VISTAíS 1977, 20, 501-521. One must know what the dependences of the reference stars are, because they indicate the significance of each reference star. Obtainable accuracy Ö orbital instability instrumental equations Ö thatís the Kapteyn method actually. Itís this work of Kapteyn thatís brought me to this country. ďI know of no more depressing thing in the domain of astronomy than to pass from the consideration of the accidental errors of our star places to that of the systematic errors.Ē (Quotation from paper.) That still remains. Itís still as bad as it ever was. So, I spend a great deal of time on that problem. Hereís ďParallax and Secular Acceleration.Ē We dispose of that first. (Section of paper).
DeVorkin:Itís basically the second order terms, in the secular acceleration, that give you evidence of perturbation, is it not?
Van de Kamp:No, no. You remove the parallax. You remove the proper notion. You remove the secular acceleration. Then there should be nothing left. If thereís anything left, thatís either error, or perturbation.
DeVorkin:The errors should be random?
Van de Kamp:Ideally, yes. And then, the orbital analysis is in the form of tables and diagrams. (Looking at the tables) — What is this anyway? This is 1950. This is right ascension, this is declination. Interesting, the accuracy in right ascension is very good in declination is not so good.
DeVorkin:This is Figure No. 4.
Van de Kamp:Yes. Figure No. 3 goes back earlier, even. But thereís some uncertainty about the earlier observation.
DeVorkin:What could cause the variation in the amplitude of the perturbation?
Van de Kamp:Well, this is the interpretation if there are two orbits, you see. One is the period of 12 years and one is the period of 19 years. Now, the 12 year period is obviously very well established. No getting away from that. The longer period is not that well established. Hereís the Gershwin quotation, ďIím biding my time, because thatís the kinda guy I amÖĒ I donít know how this will go over with the public, but I think itís lovely.
DeVorkin:This is the astronomical public youíre referring to?
Van de Kamp:Yes. Why not have a little fun? And here is, ďBlessed are they that have not seen and yet have believed.Ē Thatís good. The Rembrandt, you see the Rembrandt here. Jesus and the Unbelieving Thomas.
DeVorkin:Do you have any fear at all that, by inserting these very appropriate lovely things, people might have a wrong reaction?
Van de Kamp:Oh yes, some people will think Iím facetious. But I donít mind being facetious. No. I mean it.
DeVorkin:How could you best describe your attitude for putting those insertions in there?
Van de Kamp:Is just want to do it, thatís all. I canít help it. Itís instinctive or compulsive, if you wish.
DeVorkin:To me, it represents a very interesting aspect of your life.
Van de Kamp:— Right. I like Gershwin. And I like Rembrandt. It plays a role.
DeVorkin:True. In some small way, are you using your very well known sense of humor to poke at the people who would be your dry critics?
Van de Kamp:Yes. At the critics. No, I feel very strongly that as long as thereís an urge to say something, for Godís sake, say it! I quote myself — one thing is said in Ď38, another at the time, Ď75 — ďWhat is needed for this work? Persistence, curiosity and faith.Ē
DeVorkin:Thatís in 1938.
Van de Kamp:Ď38. And I add to that, ďcourage, resolution, charity.Ē Charity in the sense of Faith, Hope and Charity. And the charity, that is for my colleagues. For the nasty ones, I mean.
DeVorkin:Again are you implying that they should have similar feelings to you?
Van de Kamp:I donít care. And the interesting thing is, you know where this comes from, ďcourage, resolution, charity?Ē Thatís not mine. That is the motto on the Coat of Arms of Amsterdam. And I happened to be in Amsterdam at the time that I wrote this.
DeVorkin:Well, weíve spent the time very well, these last few hours.
Van de Kamp:
Well, I hope you think so. I dread to think that all this has to be written down now. Worked out now.
J.C. Kapteyn. B.A.N. 1 #14 (1922. cf. P.J. Jan Rhijn and P. van de Kamp. B.A.N. 1 #36 (1923) p. 209ff.
"Photographic Determination of the Diameter of Mars." PASP 37 (1925) pp. 261-264.
R. Trumpler, Lick Obs. Bull. 14 (1930) p. 154
PASP 77 #458, (October, 1965) pp. 325-335.
After K.F. Botlinger
Astronomical Journal 80 #8 (August, 1975) pp. 658-661.
Publ. Leander McCormick Observatory 7 (1937). Cf. AJ 45, 161-173 (1936); 45, 177-188 (136); 46, 9-21 (1937); 46, 25-31 (1937).
AJ 40 pp. 145-159 (1930). See also AJ 42 pp. 97-106 (1932).
AJ 42 pp. 161-164 (1933).
VISTAS IN ASTRONOMY (1977) Vol. 21, part 3, 289-310.
Detection of perturbation of Sirius A and Procyon A. ASTRONOMISCHE NACHRISCHTEN (1844) 22, 145.
D. Reuyl, A.J. 45 p. 133 (1936); Pub. Am. Astr. soc. 10 #3, p. 143, 1941.
W. de Sitter. KOSMOS (Harvard, 1932)
"Barnard's Star 1916-1976, a sexagintennial report." VISTAS IN ASTRONOMY (1977).
A.J. (1975), 80, 662.
Cf. page 63.
Quoted also in: Van de Kamp. "Unseen Astrometric Companions of Stars" ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS 13 (1975) p. 295; p. 299.
G. Gatewood. A.J. 79, 52; 815.
Cf. p. 63.
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