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Interview of William Morgan by David DeVorkin on 1978 August 8, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/4786-1
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Childhood and father's influence; high school in Washington, DC. Enters Washington & Lee University, 1923; becomes assistant at Yerkes Observatory, 1926, while continuing courses; B.S., 1927. Marriage to Helen Barrett. Contacts with Otto Struve, Mario Schoenberg, Dmitri Mihalis. Invention of UBV system; work on A-type stars, MK system, Ph.D. Work during 1930s on effects of metals in spectra; revision of HR Diagram, work on "spottedness" of stellar surface; changes of interest, paper on two-dimensional arrays, 1937. Problems of promotion and tenure at University of Chicago. Struve's administration, departure, and experiences at National Radio Astronomy Observatory. Decision to stay at Yerkes; effects of World War II, including Yerkes Optical Bureau and Greenstein-Henyey camera. Work on spiral arms, work with Walter Baade, William Pendry Bidelman, Jason Nassau; use of Case Schmidt telescope, and Case Survey for OB stars; paper on "natural groups"; recognition of spiral arms, 1951; physical collapse, 1952. Yerkes administration under Struve, Bengt Strömgren, 1950-1957, and Gerard Kuiper. Problems at Kitt Peak. Editor at Astrophysical Journal until 1952. Work with William Pendry Bidelman, Harold Johnson on UBV system. Associate at Lick, 1955; interest in forms of galaxies and classification schemes. Visiting professor at Caltech, 1956; contacts at Mt. Wilson; Edwin P. Hubble. Recognition of supergiant galaxies, 1960. Alfred Joy's review of Yerkes Spectral Atlas. Director of Yerkes, 1960-1963; creation of Astronomy Department at University of Texas; plans for Southern Hemisphere Observatory, eventually taken over by Associated Universities for Research in Astronomy. Younger staff departs Yerkes, courses moved to Chicago. Chairman of Astronomy Department, 1960-1966. Wife's illness and death; own illness in 1966. Also prominently mentioned are: Nathaniel Apter, Geoffrey R. Burbidge, Subrahmanyan Chandrasekhar, G. K. Chesterson, Agatha Christie, Louis Henyey, Lou Hobbs, Henry James, Phillip Keenan, Oliver J. Lee, Aden Meinel, H. R. Morgan, Henry Norris Russell, Alice Weatherspoon, Benjamin Wooten; Marvin College, McDonald Observatory, and Sky and Telescope.
Dr. Morgan, in starting out discussing your early life, I know you were born in 1906 in Bethesda, Tennessee.
Yes, a place which no longer exists, in Eastern Tennessee.
I’d like to know something about the conditions of your family at the time you were born, and the nature of your family home life as you grew up.
They were what used to be called home missionaries.
They were missionaries?
Well, home missionaries, that is, in this country. And they had been in Kentucky. There is a county in Kentucky called Breathitt County. It used to be called “Bloody Breathitt” because that’s where all the bloody feuds were, That’s where the original idea of the major feuds developed. They moved to Tennessee later, and this home missionary work was still going on. I don’t know when my father went directly into this work — he was a Southern Methodist minister until World War I. So they were living in eastern Tennessee doing this work.
Had the family always come from that area?
No. My mother was a Virginian, grew up in Rockbridge County, Virginia. That’s the county where Washington and Lee is, where I went to college for three years later on. And my father was from Alabama. He grew up and lived as a boy in a village just north of Birmingham called Warrior. It’s a mining village. The people living there were coal miners. He went to work in the coal mines when he was 12 years old. Very rough life. Well, he survived that and other things. Re was a lawyer briefly. Re had a law degree. Then, he was in the Spanish-American War and he became a semi-invalid for a period: he went into the ministry shortly after that.
Was he an invalid?
Well, he got yellow fever, which everybody got, you know. The “Yellow Peril” they called it. I don’t think he was actually in the fighting itself. But he became ill and came back, and so, he and my mother met while they were what you call home missionaries. They were from different parts of the country, especially different kinds of life. My mother’s father was a surveyor, and was from a different kind of life entirely. So then he became a Southern Methodist minister, and was subject to a famous bishop. I think it was Bishop Candler, who lived in Atlanta. I believe that’s the name. That was the man who had the job later, and I’m not sure just when he went in. But he had absolute authority, authority of life or death, as much as the Pope or more. And they would deal the preachers around. They never stayed more than four years at a place, but my father never lasted even that long at a place. There’s no point in going into the reason for that, except that it meant that we were moving every one, two or three years. Now, before that, in 1912, at least we were in Key West, Florida, at the time the TITANIC was sunk. I can place that. That’s the earliest thing I remember clearly. And my father there had a job as night editor of the KEY WEST MORNING JOURNAL, a newspaper, and this was a low point in our lives; we didn’t have any furniture in our house or anything else. Anyway, that was there, and I started to school there. I was six years old at the time. But I only lasted about two weeks in school, a few weeks, because I got a very bad case of measles, and I didn’t go back to school until I was 9 years old, in the 4th grade, out in Colorado Springs, Colorado. I don’t remember any of the details. My mother taught me all that time.
Between six and nine.
Yes, that’s right. It was the 4th grade and I was 9. So my mother must have taught me. There was no one else to do it. You know. I was not in any other group or anything. So we were moving around, and later on, the moving continued, the schools. We were in several places in Florida, and went out to Colorado Springs, and then back to Missouri in southeast Missouri. In 1914, we were still in Colorado Springs, because I remember “The Birth of a Nation” movie, I think that was 1914.
The movie, the original, when it first came out, D.W. Griffith.
What did you think about that movie?
Oh, I thought it was tremendous. That movie was terribly felt, deeply felt. You understand, the Ku Klux Klan was an entirely different organization in those days for a Southerner. Remember, I was a Southerner and I felt very strongly, had all Southern feelings very, very strongly. And the picture, (and of course now it’s criticized and called racist and stuff like that) as a matter of fact, was a magnificently liberating thing for the South. Now, I’m not a Southerner in my politics at all any more. But there were very terrible wrongs in the Reconstruction period for the whites as well as for the blacks, And it was just considered a tremendous thing, the movie was, And it was popular. It’s interesting, the attitudes toward this thing. Now, I saw it mentioned not too long ago in a paper or something of the sort, and I’ve seen it. I’ve seen it on television within the last 10 or 15 years, and I don’t see anything terrible about it still. I think it’s a remarkable work of art. All right.
Then, we moved to a place called Poplar Bluff, in southeast Missouri. And this was within a year of 1916. There, my father was a minister of a church. That town had the reputation of having the largest number of saloons for any town of its size in the United States, The average number of murders was the highest. It was a town around 8,000, 10,000 I guess. It may not be true but they had the reputation, and there was what you used to see: a saloon on almost every corner in the business district. So I was in school there. I graduated from grade school there. So World War I came out. First the war was on, at least, then we entered the war. My father resigned the minister position and got up an Army company in Poplar Bluff, and later there were three other companies. I don’t remember the names — one town was Dexter, one Donathan, I don’t remember what the last was. And he became major of this battalion. And it was his fate never to get overseas. I think he went with them to Camp Wadsworth in Spartanburg, South Carolina, where we lived for a while in the town, and I went to school a little while. This must have been near the end of the war; but the family was back in Poplar Bluff at the time of the armistice. He was with what was called a casualty detachment.
These were all the guys that had anything wrong with them, including social diseases, and every day when they had their roll call, each man had to step out and say what was wrong with him. It was not very pleasant. Anyway, this was where he ended up. He never got farther than that. The year 1918 was the time of the great influenza epidemic, the schools were closed. And this was when, as far as I can remember, the first explicitly strong interest in astronomy developed, although I remember my father had a sermon he used to preach when we were in Florida, in which he gave a reference to the Southern Cross — about the stars, the colors, in the Southern Cross, which thrilled me very much. I must have been around 5 years old.
This was a reference that he just brought in?
Well, he actually said: “When I consider the works of Thy fingers, the moon and the stars which Thou hast ordained, what is man that Thou art mindful of him and the Son of Man that Thou visitest him?” This is something out of the Bible, you see. My mother concentrated very strongly on the Bible and we read that and she taught us a lot of it by heart. Anyway, this was the topic, the wonders of the universe: “What is man in his littleness compared to the universe?” And he had this. don’t know where he got it. As a matter of fact, it wasn’t a technically interesting thing at all, but he had read somewhere. Now, it turns out that the Southern Cross itself does have one red star, together with three blue ones. Actually, there’s an association we picked out here back in 1951 on the spiral arm work, which is partly covered up by the Southern Coal Sack. Anyway, that’s the first thing I can remember of my preoccupation with astronomy. Now, I was told that I was taken out and saw Halley’s Comet in 1910. This was in northern Florida, at a place probably called Perry. The only point is, I’m not sure I remember it, You know, you get told about these things. Furthermore, it could have been 1910 and not Halley’s at all, because another bright comet came along at the same time and was more easily observable, I believe, in the Northern Hemisphere than Halley’s was, just before Halley’s. And so a lot of people saw l9lOa, I think it was, and thought it was Halley’s. I’m not sure I remember it. This is the sort of thing you hear when you’re a little kid. But later, when due to influenza there was no school in 1918, I took a piece of bamboo, and sawed a piece in the middle of each end, to put a couple of spectacle lenses in it. Well, the Pleiades looked nice because the stars were big. I thought I was looking at stars magnified. Well, they weren’t. It was a little thing with two lenses at random on each end, and all you got were extra focal images, big things, but I thought I was looking at star surfaces. I was 12 years old.
This is 1918.
That’s right. Winter of ‘17, ‘18. I think it was ‘18, I’m not quite sure. This was early 1918 or somewhere along in there, that’s right. Well, of course, it isn’t as it is now. Anybody ten years old has all the information you can get any number of ways about astronomy. You know what it’s like. Junior Astronomy Clubs and everything. There was nothing like that. You couldn’t imagine how different it was then from the way it is now. There was a magazine called POPULAR ASTRONOMY that died 20 years ago, which was a very fine magazine, but it was not of the type of thing that one finds in SKY AND TELESCOPE, or even all over the place. There was no opportunity for a person, especially traveling around the way I was from year to year, to have any real serious contact with ideas about astronomy. But the determining factor, I think one would have to say, in my becoming an astronomer came after I graduated from high school in Washington D.C. Then there was a trip back to Spartanburg for a few months and Washington one summer.
Spartanburg, South Carolina, Camp Wadsworth. This was when my father was in camp there. The war wasn’t over until the fall. So, I’m not sure, the summer of 1918 or the summer of 1919, but I think by 1919 these things had been dispersed. It probably was the summer of 1918. It wasn’t before that. It couldn’t have been before that. We weren’t in the war very long. We got in in the latter part. All right, then there was the trip to Washington. We were in Washington for a few months in the summertime.
Let me ask a few questions about your public schooling. I assume this is all public schooling?
Did you have any experiences there, in science?
Or any teachers whom you might remember?
Well, I’m going to tell you about the teachers when we get to the first year of high school, in a few minutes. But as far as that’s concerned, you see, this was a struggle to the limit just for survival. If one changes schools every year or two, especially the way the schools were then, one had a different environment, different kids to go to school with, different teachers. And I was always behind on everything. I wasn’t allowed to study on Sundays. And I remember late in high school, in Washington, D.C., I always dreaded Sunday night because I never was prepared for Monday. So it was a question of just survival. Just passing was all. And that’s what it was like all through these years.
Your family never allowed you to study on Sunday?
No. This was a religious thing. My father made the decisions. He made the decisions for the family. I’m not complaining about that. I’m just stating the reason. So it was a problem; actually, in high school, in Washington, D.C., I failed a course in math, a one semester course; and if my father had found out about it, he’d have practically killed me. Or might have thrown me out of the house. But I managed to get this report card signed without him noticing it, and took it the next time and made an A in it the next time around, and pretended it was a one— year course. Well, this is what grade and high school were like. It was a different environment, a different place every couple of years, different children, different requirements, everything all the way through, until departure for Washington and Lee University in Lexington, Virginia in the fall of 1923.
That was already after you’d become interested in astronomy?
It depends on what you mean by being interested in astronomy. It was a glamorous area to me about which I knew practically nothing. I didn’t know anything about it. And the first time I made any real efforts to find out anything about it — the only serious ones started in the first year of high school, when I was 13 years old, in a small, religious junior college (Marvin College) in Fredericktown, Missouri — a small town in southeast Missouri.
How many brothers and sisters?
I had one sister and she was a year and a half younger than myself. She was at this time with us. We went different directions when we were in Washington later on. After the war my father didn’t go back to the ministry, he joined something called International Correspondence Schools as a lecturer, to go around and lecture to police groups, street car conductors and this kind of thing. In other words, they were good and they were serious things, but the idea was that they would subscribe for these mail order lessons to improve themselves, and he was in that. When I saw him last in 1926 he was doing that. In the fall of 1919, my mother and my sister and I ended up at an institution called Marvin College, in Fredericktown, Missouri. Now, that’s a little north of Poplar Bluff, south of St. Louis, maybe 50 or 100 miles, And this was a little junior college, which actually had a cow pasture around it. It was denominational but I don’t know what the denomination was, in a little town. My mother was the matron or something of the dormitory, which had both boys and girls in it. Everyone lived there. It’s a different kind of thing from now, of course.
This was a very small thing, and I went to the first two years of high school there, Marvin College folded some time before 1939, when I drove through Fredericktown on my way to Ft. Davis, Texas, to attend the dedication of the McDonald Observatory. At Marvin, in my first year of high school, I took Latin. My Latin teacher was Miss Alice Witherspoon, a very remarkable young lady probably in her mid—20’s. I have never heard of her since my departure from Marvin in 1921. I went back through there in 1939 and the building was standing just empty, no one around at all. It was operating just at the borderline, and it disappeared. Miss Alice Witherspoon started me off in astronomy. There happened to be a theodolite, a one—inch theodolite that was in the college equipment. This is old equipment, old books, everything was old in it. And that was fixed up. She fixed it up on a little stand and we looked at the moon and various things, opening a window in the library at night.
This is your Latin teacher?
That’s right. And she bought me my first, she gave me my first astronomy book. It must be somewhere in the house still, I can’t find it. It was a companion book to Charles A. Young’s text, LESSONS IN ASTRONOMY, which is a remarkable book. I have that text, which I bought in Washington a couple of years later, but this original companion was called URANOGRAPHY, which is Greek for “description of the heavens.” Well, it was the star maps from that text bound together in a little booklet with a black leatherette cover, and that’s the first thing I had.
That was by him too, as a companion to the text?
Young. It was simply an excerpt from “Lessons in Astronomy.” That’s right. C.A. Young was in some respects a much more important person than he’s been given credit for being. Well, then it really was very serious, the interest in astronomy. I must say that not for a long time after that did I think of becoming a professional astronomer, because I was in a survival pattern in all senses, those next few years. But I’ll get to that. Am I talking too much in detail?
No, it’s fine.
So this is what this lady did, and as a matter of fact, in a certain sense, it saved my intellectual life or my mental life, for that matter, this thing. It was more than a hobby; it was an overpowering longing.
At that time. Did your parents have goals for you?
Well, you see, I don’t know about my mother. My father always wanted me to go into his field, which was in effect public speaking, whether religious or not. At one time I thought I would be a minister, but that did not last very long. In fact, the last summer I was at Washington and Lee (1926), just before I came out here, he set up a program whereby I went around visiting different manufacturing plants in the state of Virginia. He had gone and lectured at these places, and he set it up for me to go to the same places. I’d just go from one to the other the whole summer. My father was the kind of person who did not welcome differences in opinion. It was a very rough life. So this was the kind of thing he wanted me to do.
When I got the offer of an assistantship from Yerkes Observatory he said (in fact, this is the last time I can remember talking to him about anything; this must have been the late summer of 1926) “Well, you’ll end up just in a laboratory working for somebody else, that’s nothing.” But I went anyway. So he had the idea that I would follow in his footsteps, in some way, which was anathema to me. He was a public person; that’s not a pejorative remark; but he was a public person, and I was exactly the opposite; in the early years, it was a defensive position; but in the early years at Yerkes it became clear that the person I wanted to become, in order to carry out the work I wanted to do, was a very private person — one who could spend much of his time quite alone (in the company, of course, of a family and a few close friends). The public life would have barred effectively everything I was determined to do. My father, in a sense, was a very great man. He told me once it took two generations to make a gentleman and he was the first. His father was the same kind of person he was. But it was a very, very rough life. These months, these years, it was just a question of survival, just keeping one’s head above water. That’s what it amounted to for this person in those days.
Well, once you were stimulated by Miss Witherspoon, that started a change in your mind?
Not toward a professional career. No. Because mine was a sort of a lower middle class type life; and if a child has a survival problem, from the time he has any consciousness it’s just a question of survival. I’ve heard of things that I don’t want to talk about — there was abuse when I was very small, physical abuse and that sort of thing. But I have to say right now (I might forget to say it later on), if I were to go back, if I could have changed anything in that background, I wouldn’t change a thing, because I never could have gotten to where I was later on. I’m not talking about as a public figure — that means almost nothing to me — but to have gotten to the kind of profession and range of interest and depth, and in particular, to a kind of drive which some people say “one is born with, it’s built in with you when you’re born” — I don’t know about that. And this is something that I’m not an expert in, But it almost seems sometimes that if people do not have to struggle very hard for survival when they are very small, most of them do not find their kingdom. They drop off. It’s the end of them. They die or they give up or all sorts of things.
There are exceptions like George Hale and people like that, but at least for me, I would not change anything, except I would have hoped my mother would not have as bad a time as she did have in her married life. So then there were two years in high school at Marvin College in Fredericktown, Missouri, and then, we moved to Washington. All right. We go to Washington then. My father is traveling, still for the International Correspondence Schools, and we lived at 3522 13th St. N.W.
You lived in the Northwest part of Washington?
That’s right, and now it’s completely black where we were, but I lived about a mile north of Central High School, the biggest high school there. I used to go every morning, take a streetcar down. It’s completely different now. You wouldn’t even recognize it. My father bought a house there but it was never paid for. There was little equity in the house, but we lived there. So I go then from this dinky little Marvin College into a high school of 5000 or so. There were 491 in my graduating class. In the first year there it really was a survival problem.
That’s big. That’s a big high school.
As far as science was concerned there was no science contact at the place. They may have had shop or something. So I was two years there, and I graduated then, in the spring of 1923, 491 in my graduating class. I must have been the only person who applied to Washington and Lee University, down in Lexington, Virginia. They offered a scholarship for students at this high school.
That’s Washington — Lee?
Yes. This is an old school; it goes back to the 1700’s. This was something called Liberty Hall, later Washington College in the late 1700’s after George Washington. In fact, there were two brick walls still standing out in a corn field, when I was there, from clear back I think, before 1800. And it was still Washington College until the Civil War. After the Civil War, Robert E. Lee became president of it and died, He wasn’t there very long. And it became Washington and Lee University, So I went down there. I was helped with finances because I did get a scholarship. For the rest, my father paid the way. It wasn’t a question that I had to work for that.
He did agree?
Yes, Oh, he wanted me to go to college. He wanted me to specialize in other things than I did. There’s one thing that I think he’s responsible for, that I have to give him credit for, and I’m quite sure it’s true, and that was getting a general education. As a matter of fact, this is the most important thing in education in my life. He insisted it had to be so. He insisted that I have a general course rather than start specializing in certain things from the beginning. Now, this is all modern stuff now, but it’s a very strange thing for a man of his background in those days. Well, in that sense, I had to do what he said. So you know, I’d had four years of Latin already, and I had another year, and ran into this fantastic thing. There’s no time for all these things.
An old professor called “Toady” Kern by the students. Toady’s a nickname, of course. In his class we would spend months on a few pages of Latin and it was things like Ovid and stuff like that. I had had Caesar and Virgil in high school long before that. Now, this has nothing to do with astronomy; except, in a way, I’m not sure; it’s the first time I’ve thought about this, This could well have been the beginning of what one might call the concentrated intensive examination, outside of time. By outside of time, I mean that time is not a factor in what you’re doing. You’re not conscious of time. If you’re conscious of time it doesn’t exist. This is a characteristic which is one of the most important things in my entire life, and it could well be — this is the first time I’ve thought of it — the main thing I was thinking about before. You’ve got to give my father credit for this.
This sounds very important — that you became so engrossed, involved in your study of Latin?
Not involved. I didn’t particularly like it. I had to take it. My father wanted me to take it; so I had to do it. You understand, before you’d have a big assignment, of a lot of Caesar or Virgil or Cicero, all this stuff, and you had to cover it rapidly; and this was murder; I never got it covered well. But instead of that, this man would concentrate, just stay with a few lines of something, maybe for a whole hour — or several hours, And I must tell you; this is interesting; this is a rather Proustian thing, because it never occurred to me before; this could well have been the beginning of something which has been a major factor in my life after. But I never thought of it until we’re speaking about it now, Because other classes had little of comparable importance. Some English courses, for example: Early English Poetry (“Sir Gawain and the Green Knight,” etc.) for exceeding simplification and compression into few words for the deepest conceptual inventions. All right, the science at Washington and Lee was chemistry and physics, I had some of both. I never had advanced courses in either one. And I took math of course, and if I’d gone back for my senior year, I had won a scholarship in math.
Oh, you didn’t actually finish your senior year?
I’ll tell you about that. No, I wasn’t there for my senior year at all, So anyway that’s what it was like. In math we had differential equations and integrals and things of this sort. And of course I was only there three years, but I remember what impressed me most of all was the library. Now, it is not that it was a modern library or had lots of contemporary books. As a matter of fact they’ve just now built a new library. But it had representative works of greatness from the past. In a certain sense, I could not be described as a scientist at all. But anyway, this library, it had works in parchment — Latin classics — all sorts of things going way back hundreds and hundreds of years. They meant a great deal to me, a tremendous amount; how it affected my astronomy I can’t tell you; but I have a strong impression that these non—scientific works constituted one of the determining factors in the development of my personal phenomenology.
As far as astronomy’s concerned, I talked my physics professor into buying a small refracting telescope. So my physics professor at Washington and Lee was named Benjamin Wooten, and I talked him into spending several hundred dollars to buy a four—inch astronomical refractor. And I used to use that for observations of the sun. The telescope was mounted out on the roof of the physics building. We carried it up. There was no organized research carried out; sunspots were observed by projection; and I do not recall other uses. But this was the first direct contact with an astronomical telescope, except that once, probably in the summer of 1919, in Washington, my uncle who was a dentist in Washington, arranged for us to visit the Naval Observatory one night. And the astronomer, H.R. Morgan, a little black cap on his head, was demonstrating the 12—inch telescope for visitors. This was my first contact with professional astronomy. This was probably just before I enrolled as a high school freshman at Marvin College in Fredericktown, Missouri in September, 1919.
Was there any association because his name was Morgan?
No. I just exclaimed: “Gosh look, the man’s name is Morgan.” We met later. In later years, we corresponded concerning our research, He was an outstanding worker in positional astronomy. That was the first contact with astronomy. Now, the next thing that happened, through some combination of circumstances, Dr. Wooten came through Williams Bay in the early summer of 1926. I had finished my junior year at Washington and Lee and would have been a senior in September 1926. Dr. LB. Frost was director of Yerkes at the time; a blind man, He had become blind progressively from around 1915—20. But it was not due to his astronomical work.
He was completely blind at that time?
Well, no. He was normally blind completely, but he used to go to Chicago and have drops in his eyes for examination, When he returned from one such trip, he said to me: “Let’s see what you look like,” and he tilted his head far backwards and looked through the bottom of his eyes. At such times he could read headlines of newspapers. It turned out that Oliver J. Lee had been at Yerkes since around 1910 or ‘11, and had never been promoted to tenure at the associate professor level; he was still an assistant professor. I don’t know how Dr. Wooten happened to visit Yerkes Observatory. He told Dr. Frost, that he had a student interested in astronomy. I had no idea of this at the time. I was specializing in English literature at Washington and Lee, and the biggest thing I could imagine was I would be teaching English literature in some high school later. Then Mr. Frost told Wooten that he would offer me a position as assistant. They were going to get two young people and bring them up to take the place of Oliver Lee, who was leaving. So I accepted it. This is when my father said, “You’ll end up in a laboratory working for someone else”; and of course, he wanted me to be something entirely different. I arrived here on Labor Day, 1926. The railroad station was jammed, with summer visitors. All around the station was jammed. Dr. Frost came to the station to meet me (with a friend who could see), but having no idea what I looked like, they missed me.
This was when the train came to Williams Bay.
That’s right. So I didn’t find anyone, so I walked up the hill. Dr. Frost was here, and he greeted me very pleasantly. I lived in the observatory in the basement until I married in 1928. At Washington and Lee, I had had three years of math, just through differential equations. And in physics, two years of physics and through what was called industrial chemistry, in chemistry. But I’d had a lot of other things which my father wanted me to have. My father—in—law to be, Storrs Barrett, was on the staff here, I started observing with him on the Bruce Spectrograph, doing spectra for determination of radial velocity of B—stars.
You got your BS in 1927.
Yes. It turned out that in that latter part of 1926—27, I was taking courses, which were informal here, observation of variable stars, etc. I’m the only person who ever got an undergraduate degree from work at the observatory; no one ever thought of trying it before. There was no law against it because nobody had ever tried to do it. And it turned out that I had more credits at Washington and Lee than for the full three years, but I was given credit for these informal courses. There was an examination in English; I took it and passed it. So I received a Bachelor of Science, in June of 1927, without ever having attended the University of Chicago. I went a few weeks before that, went down once to the University and looked around the place. I didn’t know a single person in my graduating class. 1 was married in June, 1928 to Helen Barrett; she died in 1963.
Your wife—to—be was the daughter of a staff member here?
That’s right. She was secretary to, I think, the director of the University of Chicago Press, Donald Bean. He later went to Harvard. He’s dead now. The academic year 1929—30 I spent on the campus to try to make up some courses I had never had.
This is really as a graduate student.
I was a graduate student but I was taking undergraduate courses, in effect. I got credit for them.
By that time you’d already published a number of papers with Struve, 
Well, not a number. A paper on 95 Leonus with 0. Struve, “A spectrographic orbit,” and I had a short paper on a star called CP Cygni, it’s in POPULAR ASTRONOMY; an error had been made in the published period; I found the real period. That’s the first thing I did by myself. I did a lot of visual observing of variable stars, and actually computed a photometric orbit from my visual observations of a star called Z Z Aurigae. The observations were just determinations by Argelander’s method. I don’t like the word “estimates,” because they were better than .05 magnitudes you know, together. And it’s a serious orbit, it had reflection effects, reflection and heating. Then there was a star called AK Herculus. I think it was a visual orbit.
AK Herculus, right. Let me ask you this. You came to Yerkes. I’d like to know whom you associated with here, who trained you at the telescope, whom you worked with?
When I got here, Struve at the time was an instructor, I believe. He had gotten his degree the year before. I think he got his degree in 1925.
And he was out, he was out at Victoria at the time of my arrival; then he went down to Mt. Wilson. This was an interesting trip, because at Victoria, he asked if he could look at their spectra of 0 and B stars, and he went to work estimating interstellar K lines on those things. He demonstrated the growth of interstellar K with distance. But he was away then. He came back in the fall and I met him. I can’t remember the first few months, say the first six months or so, even maybe the first year. His influence was, far and away, the most important in my formative years as an astronomer. He had an intense enthusiasm that he transmitted to me, and was the sound basis on which I was able to build. He used to be at the Observatory at night an awful lot, even when he wasn’t observing; and of course I lived here at night.
He made the remark once that he never looked at the spectrum of a star, any star, where he didn’t find something important to work on. Now, that, in the light of the last half century or so, could be considered a slight overstatement, but this is the kind of statement which, even if it’s an overstatement, can build up tremendous interest in a field, and in attitude toward any kind of investigation, whether it’s science or philosophy or anything else. It doesn’t mean that one is consciously overstating. But one can put something in a very few words, so that the number of words one is using are obviously inadequate to really give a picture at the detailed level that one could give it, but it can be put in a certain very few words, that can serve as a catalyst to the person, and as a sort of a permanent symbol for work and attitudes.
My astronomy would not be what it has been if I were not at the same time a number of other kinds of people that I don’t talk about. I have one, maybe two books on astronomy at the house; I have probably a thousand books over there, altogether. But the point is, the kind of astronomy I do — and some people say I’m not an astronomer at all, they can make a case for it — is strongly influenced by the kind of person I became. Certain literary influences and philosophical influences have been of tremendous importance to me in the kind of astronomy I chose to do.
Could you identify them now?
Well, the earlier ones in the 1930’s, was Agatha Christie’s detective stories. Not that they’re perfect, but the way that a germ can be developed and so surrounded by underbrush. This is a phenomenological remark and I’m very serious about it; these Christie paperbacks are stacked up in my bedroom. Very rarely I re—read them, once in a while. But it’s remarkable that the two persons having the greatest influence in the earliest years (this is the 1920’s and thirties), were Christie and G.K. Chesterton. Especially his FATHER BROWN detective stories, which I began reading in the middle 1920’s at Yerkes, have had a tremendous influence. To start with, I was not satisfied with what a scientist was supposed to be. There was a certain glamour; but I had a strong feeling that there was something much deeper and more vital in science and philosophy than the popular ideas on these subjects in the 1920’s and 1930’s, These feelings have grown progressively up to the present, and form the conscious motive force for my work in the 40 years since 1940.
Then, there was a man named Mario Schoenberg. He’s still alive. He called me up from Chicago around 1976; I hadn’t heard from him since 1941. He called me up a year ago from Chicago. He collaborated with Chandrasekhar. He’s a Brazilian, and he was here for a year in either 1940—41, or ‘4l—’42 to work with Chandra. Of course I respect Chandra very, very much; but we live in different worlds and my creative world, my phenomenological world, has no point of contact with him. I have nothing in common with his way of looking at things. I am as much an a posteriori person as a person could be. I start with the specimens, look to try to see what they’re trying to tell me in their natural habitat. Certain orders and regularities appear to be present. It comes up from there. Now one of my closest friends, both scientifically and personally, is a pure theoretician: Dmitri Mihalas.
He had the office across from me for a couple of years. He says that in those two years, his attitude toward astronomy was changed, that he did not change from being a theoretician, but have you seen his revised STELLAR ATMOSPHERES? It’s completely rewritten, and I can’t understand how he feels about me the way that he does, but you look at the acknowledgement in the introduction to that thing, which I tried to stop, and he said, “Well, it’s true. Are you going to make me take it out?” And I said no, I wasn’t going to do that. Anyway, the main thing I’m getting at is that my approach (and this is the approach I had from the beginning — but it’s only in the last five to ten years that I have realized what it was) can be best understood from the title of a book by Sartre. Sartre wrote (it may have been his doctor’s thesis) a book translated by Hazel Barnes; the English title is SEARCH FOR A METHOD. That, in a sense, is the story of my life.
I’m interested in classification.
Classification is now a pejorative statement. You know, these classifiers look like “dumb fools.” I’m a classifier. But I’d like to use a word that includes more than what people consider is encompassed by classification. It is more than that, and it’s something which can be called phenomenology, even though the word phenomenology has become somewhat loaded by the work of Husserl; and I do not go with his later developments. But I refuse to let a person spoil a word just because he got to it first. And there’s nothing as close as that word. You mentioned influences. Returning to Sch8enberg, I didn’t see much of him the first nine months he was here, and then we got to talking. We talked all night, on occasion.
The greatest of all spectral classifiers, Antonia Maury had two strikes on her: the biggest one was, she was a woman. A woman had no chance at anything in astronomy except at Harvard in the 1880’s and 1890’s. And even there, things were rough. It now turns out that her director, E.C. Pickering, did not like the way she classified; she then refused to change to suit him; and after her great publication in HARVARD ANNALS 28 (1897), she left Harvard — and in a sense, astronomy. The men smiled on Miss Cannon, who did the Henry Draper Catalogue. I had quite a talk with her around 1936, and I saw how she classified stars: she had an eye piece like this, only it was much lower power, but the striking thing was that she had to hold it in the air instead of placing it on the glass, at a constant focus. And that’s the way she did the whole Henry Draper Catalogue. Hanging up in the air like this. And if you do that, you can’t help changing the focus a little. That means your eye jumping back and forth focusing all the time. That’s the way she showed me, she was doing it, still classifying when I was there. Her eyes were fine.
She was a glamorous lady and she did important work in astronomy. But the greatest thing, as far as I’m concerned — I would say the greatest thing in pure (classification) — was Miss Maury’s work. I’m not talking about spot discoveries; you point a telescope at something and there it is sitting in front of your eyes. I don’t mean that. But classification is not a discovery process. I would say the most remarkable phenomenological investigation in modern astronomy is Miss Maury’s work in HARVARD ANNALS 28. She didn’t have anything astrophysical to go on. Investigations between 1890 and 1900 were the origin of astrophysics. But these were solar, mostly. And there Miss Maury was on the periphery. I’ve seen pictures of groups, where she’d be standing away a little bit to one side of the other people, a little bit in the background. It was a very sad thing. When Hertzsprung wrote Pickering to congratulate him on Miss Maury’s work that had led to Hertzsprung’s discovery of super giants, Pickering is supposed to have replied that Miss Maury’s work was wrong — could not possibly be correct.
Were you aware of her work in the twenties before you first came here?
No. We lived up by DuPont Circle in Washington when I was in high school there, and I’d walk one of the diagonal avenues, I forget which one, all the way to the Public Library, which was clear down at something like 7th. It could have been four miles. I would read POPULAR ASTRONOMY there and also the JBAA. They took it there. And that’s all I ever saw in astronomy till I came to Yerkes, Together with my book LESSONS IN ASTRONOMY, Charles Young, and Garrett Serviss’ ASTRONOMY WITH AN OPERA GLASS (written, I think, in the 1880’s). The reason I brought up Mario Schoenberg’s name was because he alerted me to Proust’s A LA RECHERCHE DU TEMPS PERDU. (REMEMBRANCE OF THINGS PAST). My first wife and I had just joined the Book of the Month Club around 1930, and got this two—volume English version as a bonus. Proust had always been a dirty word — you didn’t mention him in polite conversation; you didn’t put it in your library.
And it wasn’t till Schoenberg was talking about this in 1940, ‘41, that made me realize what was there. Now, this is as far from science as you could say anybody could be, But I have to insist that in particular, the last volume of Proust called THE PAST RECAPTURED was of great influence upon me. A LA RECHERCHE DU TEMPS PERDUS, or “In Search of Lost Time,” and that’s the way it should have been translated, IN SEARCH OF LOST TIME. The novels and essays of the American, Henry James, began to have a very strong influence on me in the mid—194O’s. The next thing and the determining factor — what pulled the different things together — was the discovery of Ludwig Wittgenstein. I realized with astonishment as I read his later work, that they were supposed to be difficult. You’d say, “This man is difficult.” Well, I have very little difficulty with his great, later works. But he is not generally appreciated for what he was. For example, we had a very distinguished philosopher in the Philosophy Department at the University of Chicago who is now retired. I asked him,” Do you still consider Wittgenstein important?” “Oh, yes.” I said, “The PHILOSOPHICAL INVESTIGATIONS?” (1953 ) He said, “Oh no, THE TRACTATUS.” This was his doctor’s thesis clear back in the early 1920’s. He left a manuscript at his death (he died in about 1952), called PHILOSOPHICAL INVESTIGATIONS, which he’d worked on for five to ten years before that; and this, to me, is the greatest work. It is not scientific, in the strictest sense; but it furnishes an atmosphere in which the greatest creative work of the future can be done.
I’m really interested in how Wittgenstein’s work influenced you.
This is a very difficult thing to talk precisely about. The factor which affected me deeply was a matter of recognition, not of reading something new that I didn’t know about before. Well, you ask how it influenced me, conceptually. Conceptually, the later Wittgenstein confirms me in a kind of research and a kind of life which I have carried on at least since the Yerkes publication on the A stars, (I think 1934, ‘35). Something in the later Wittgenstein seems to explain and justify a private conceptual growth that began in the mid—l930’s, and that is illustrated in my research papers during the following 45 years.
Was that “A Descriptive Study of the Spectra of the A—Type Stars?”
That’s it. Stebbins and Huffer investigated the north galactic polar region using their narrow base colors, The photometry is very good. They found a color excess of up toward a tenth of a magnitude, and total absorption, or extinction as they call it now, of around quarter of a magnitude at the North Galactic Pole. Well, I didn’t believe it could be right. I got spectra of these stars. These were A stars they were using, intrinsic colors from the A’s, and it turned out there were a number of them classified as AO from the Draper Catalogue. But there wasn’t a single real AO star there. There were a number of A3 and AS stars, and a number of metallic line stars. The intrinsic colors, then, are of an order of one or two tenths of a magnitude redder than they had assumed, and that knocked out the whole thing.
Now, Bidelman and I had a little paper in the APJ about 1946, that says nothing about UBV or anything of the sort. But that was the principal paper along the way toward the UBV system. The latter was joint work with Harold Johnson: He made all of the photoelectric observations and devised the Q Method. The UBV system itself was devised by me; and I wrote most of the paper.
Did you actually design the band passes yourself?
Not in detail, just the regions. The U was terribly important. In spite of the fact that people go to U minus V — instead of U minus B and B minus V — and destroy its principal value; the U—B gives you the leverage for the Hydrogen Dip.
I know this is getting ahead and not chronological, but it’s important. Was it Johnson that first noticed the Hydrogen Dip?
Or was it you?
Yes, The UBV System could never have been done without two people. Later on, as in Volume III, the third volume of the Kuiper Series, Johnson wrote that all you need are ten stars to define the UBV System. This is simply not true. He actually, in the original UBV paper, didn’t re—observe the Super giants, G and K Super giants. He says, “Oh, you can reduce those from the PV System.” He finally observed them again. But he has never accepted the fact that one needs to have a great variety of objects, including white dwarfs and a range in luminosity classes, to define it properly. He says, “Well, if you’re at a height of 5000 feet above sea level and you have a freshly aluminized mirror, and you have Corning filters number ‘so and so’ and number so and so with certain thickness — “ (Of course those don’t necessarily stay the same with time either). That you define it. But the system has to be based intrinsically on stars, if you want to retain the highest possible accuracy and discrimination.
Not instrumental bases.
Right. And that is the strength of it, and it was designed to be a concomitant of the NK classification system. The UBV System deserves to be considered more carefully than it was considered in later papers by Johnson, where he stated that a dozen stars will define the entire system.
Now, there is a paper called “Relationship between Color Systems,” which has rarely been referred to; this paper was prepared by the late Daniel Harris and myself; the name of Harold Johnson was added quite properly, since he had made a number of the observations used. It turns out for some reason that I’ve never found out, that the slope of the reddening line in that paper, from the Least Squares solution by Dan Harris, was 88/100, not 72/100, (the value now used), and I’ve never understood the cause of the difference. This is the paper that shows, for many different color systems, how complicated the relationships can be, so that you need information for all kinds of stars, for satisfactory reductions from one photometric system to another.
OK. I’d like to get the reference on that. “Some Characteristics of Color Systems.” We’ve consulted the Science Citation Index on your papers, and there are 32 citations to that paper.
That much? Well, I’m interested. I never knew of one of them. The original paper (APJ, 117, 313, 1953). One of the most cited papers of the decade.
Right, that’s “Fundamental Stellar Photometry for Standards of Spectral Type in the Revised System.”
Was that listed under Johnson’s name first?
Johnson and Morgan. I put it that way; it’s alphabetical.
It is not a good system, you know, to have just one name and then “et al,” in the thing that you’re working from,
Oh, the SCIENCE CITATION INDEX. Yes.
Because very often, they’re alphabetical.
That’s right. That’s one of the criticisms of the system.
I’m surprised that I didn’t have any citations for the UBV system.
That’s just the problem, because that was (under) Johnson’s name.
Well, it’s called the Johnson System now, did you know that?
I’ve referred to it and heard it referred to as Johnson—Morgan? I see. the ‘53 paper with Harris and Johnson was a comparison of the MK Classification, UBV Photometry. You were just out of the hospital then.
Yes, Our paper was in APJ 118 — 92, and “Some Characteristics of Color Systems” was the title of it. I would like to show you some of the original paper.
We are looking at Page 93 of “Some Characteristics of Color Systems,”
This little part here was in the original paper. But you see, obviously, there is something different, but it’s a very strange situation. This thing here, Dan Harris did. He was a very fine photoelectric observer of stellar magnitudes — perhaps the finest who ever lived.
Now, there’s something important about these stars, compared with others; in a certain way you might say, in a negative sense. Here are the C—1 colors of Stebbins, Here’s B minus V and C 1. The discontinuity...
That’s in Figure 3.
...Discontinuity between giants, G 8 to K 5 Giants and look at that.
Yes, that’s strong.
All right. Now, I don’t say the relationship is linear. But I say, this is somewhere close, and you’ve certainly got a discontinuity. Incidentally, when John Neff and I split the U—point (of course others have done it since) and integrated on galaxies, we could get some idea about giant—dwarf populations from that thing. And then the work with him collapsed completely; it wasn’t published. But if one defines what one’s doing carefully enough you can split the U—point and use it. This is not new. One can get a lot more information on stellar populations in galaxies in this way. In this sense, you’ve got to have standards. Again, you get to this question of conceptual precision, you see. You have to have standards for the same kind of creature that you’re going to be observing. You can’t go from one kind of specimen to another kind, and do photometry and think that you can draw precise conclusions. You say, “Well, you can make comparisons with low accuracy” or something of this sort; but the main thing is, if you want to go to the limits that the method will give — and the observations will give — you have got to take the UBV system and have it defined in terms of the objects you intend to observe.
In terms of the objects themselves and not instrumental parameters.
Yes, Right. Because it is basically the same thing as in work in spectral classification. One should write a book about the fundamental ark standard, Gamma Pegasi, B2 IV; what’s it like in all wavelengths. The point is, you need to get two objects that are very nearly similar to each other, and only then can you make very sensitive comparisons between them; one of them, you have to assume, is standard; or, you have the whole system floating.
This is the thing that’s been the principal preoccupation I’ve had in many years. And It’s an interesting thing: Dmitri Mihalas (a theoretician) understands it. You throw away so much of the possible differential precision when you choose to make absolute statements instead. As a matter of fact, there were most completely fundamental two points to the MX System: G2 V was defined by the sun, and AO V by Vega. The choice of the sun to serve as a fundamental standard, now seems to have been ill—advised; it is too difficult to observe the sun and avoid systematic effects because of its proximity and brightness. It was chosen originally in the late 1930’s because we knew so much more about it than any other star; but this advantage is lost because of the difficulties in observing it with low dispersion. For Galactic Structure work, we need low dispersion. We can classify quite accurately that way. If you use measures like the Str8mgren system, every time you re—observe a Stromgren standard, you change the equivalent width of H. Every time you observe, you change it. You have no precise system.
You can’t reproduce it.
In a sense, in the most precise sense. This is why the spectral classification approach is still an absolutely fundamental one. The Stromgren system is very important also.
I told you about the conversation with Struve, in which he mentioned his excitement for any spectrum, and of course some of these spectra weren’t too pretty compared to contemporary types.
Wait a minute, what was the story?
He never looked at any spectrum without finding exciting things he wanted to work on.
So I got interested in A type stars. You see, there was one “manganese” star, Alpha Andromedae, that had published line lists in the 1920’s, I think, This was just the time when they were separating out some of these ionization stages. And there was 1.00 Europium star, Alpha Canum Venaticorum, which went back quite a bit earlier, and that was just from arc and spark spectra. And there was one, called Epsilon Ursa Majoris, which one cannot describe with ease or label it the way one does the others, So there was Alpha Andromedae, Alpha Canum Venaticorum, and then there was Theta Aurigae, which goes clear back to about 1900. There’s a paper where three of these are described before 1900 in the MONTHLY NOTICES. Theta Aurigae has certain lines strong. Well, the silicon lines were strong, but certain other things clearly too, the chromium lines were strong. So — and this is about as purely a posteriori as you can get — this is a good sample, of the beginnings of the method I was speaking to you about, where one simply tries to live with the specimens as closely as possible, in a purely descriptive kindergarten fashion. “How come there’s only one of all these different things?” You know. So I went to work. And just on the plates we had here.
You were fascinated by this?
The uniqueness of only one example which I didn’t believe that God in His wisdom would do, I wondered, “Did He just make only one of those?” That doesn’t look right. You know, esthetically. I don’t care what you want to label it, So the first thing I did was to go through the spectra and the first thing I found — then I found a batch — was a star that we used to call —18° 3789. Which is HR 5355, and that was I think the star that much later, was discovered to have a magnetic field, That was the first one of them, I think. Anyway, it’s one of them. But anyway, Hujer had taken three plates of this star. On one of the plates, there were real strong lines of Ti II, Fe II, and Cr II, all the way through it, and on one of the plates you could hardly see any at all. Just like that. Well, I took some more plates, obviously. 73 Draconis was another one that turned up with these kinds of things, you see. Anyway, I found on the order of half a dozen to a dozen of each of these things, and this was my thesis, several different papers.
Three papers, studying these peculiar stars?
One, two, three, that is my doctor’s thesis. 73 Draconis showed beautiful changes in these lines that I was just talking about, In Horace Babcock’s ASTROPHYSICAL SUPPLEMENT #30, published in, I think, in 1950, and which I’m using for something in connection with the SPECTRAL ATLAS here, he says, “This was reported by Morgan. We have not been able to see any variation in our own plates.” But I’ve got spectra illustrating these changes. Now, he’s polite, so he said, “Well, the thing must have changed in the meantime.” Boy, I’ll say it did. This isn’t any little minor thing, you know. All right, then, that’s the way it started. That was how those papers were published. Then there were papers on individual stars, some of those that turned up a little later, And that’s the way it started. That’s right. The first paper which is really quoted, quoted rather frequently in general papers now, is a paper on the possibility of a peculiar sequence of stars in the A’s, the late B’s and early A’s. And it’s interesting, that has been “Improved” by a number of people — no names mentioned, they’re my friends. But they always overdo it, go too much in detail to get too much, too many different kinds of things. For example, getting metallic line stars in B8 and things of this sort, which, you know it may be a similar phenomenon but I’m not sure. But that paper really is quoted quite often still. I would like to show you two color—color plots.
These are the papers from 1953?
That’s right. It’s in here somewhere, All right, the whole thing is in the first paper. This is the one I was thinking of, for the bright star and there’s the color, the reddening line you see down here — these diagonal things here.
It shows a great difference in angle between the reddening line and the thing for the B stars.
Yes, tremendously different, I’m just defining it for the tape: This is Figure 10, for your paper, “Fundamental Stellar Photometry for Standards of Spectral Type on the Revised System of the Yerkes Spectral Atlas.”
Right, but it does have these things, but the place where it’s labeled and the things are identified first is here, although it does appear in earlier work.
You do have the dips.
It does have it. That’s right. Now, that’s right, all right, now you are welcome to have that if you want. I can’t give this other paper to you because I am insuring some that I have, I want to have a good copy for myself and one or two friends, if I later publish a volume with about a dozen papers over the whole time, if I’ve got enough money to do it, later on. Just a private venture.
In 1933 you also had a paper on the effects of change of absolute magnitudes and change of temperature.
That’s a very important paper, because that was the beginning of a sequence toward the Yerkes Spectral Atlas, 1943. You’ve got ‘33 for that?
From three prism plates? Yes. The high dispersion plates. All right, that really was the start. The Zeroth approximation, the start toward the Atlas.
I’d like to show or have some of your recollections of how you came to that first paper, which you just referred to as your “zeroth order” work on the effects of metals in spectra and the effects of changes in absolute magnitude and changes in absolute temperature on the spectra of stars.
Well, it’s like this. I have a pretty good memory for some things, most of them unimportant things, but all I remember about that is, I gave a colloquium on it here, and Struve was very impressed. See, he would jump on interesting things, God bless him, you know, he was an astrophysicist. He used the observational work as a tool. The observational work was used to get somewhere, in physical interpretation. Now that doesn’t mean that that isn’t why observations are made. But for me, there is a whole area of science where one is at a level, a pre—interpretive level. For example, that 1935 paper, it was the first time that the discussion of the approximate constancy of log g along the Main Sequence came up. That’s the first time it was ever mentioned. The first time in the literature. It never was before, and it’s never been referred to since, as far as I know. The log g changes somewhat, but the whole slope of the Main Sequence almost disappears, when you go to the ‘35 paper.
This your study of surface gravity that came in right at that time?
Just let me look.
It was in ‘35?
The only date I remember exactly is the UBV paper. The paper I’m talking about is from 1937, “Descriptive Study of the Spectra of A to K Type Stars.” That’s where the g comes in — the similarity, almost the constancy, of g along Main Sequence. I always was surprised that that didn’t attract any attention, you know.
You interpreted the H—R Diagram with respect to temperature and surface gravity.
Yes, that’s right. I think that’s the first time it was done. It doesn’t seem possible, but I think it was. Well, now, this is the one. Let me see what the Abstract says. (reads abstract of paper) I think that’s an interesting thing, a very interesting thing. make no pretensions to it. And I never get caught, or commit myself, on the interpretive points, you see.
Well, I was interested in that particular paper. You acknowledged Henry Norris Russell’s aid.
Actually, as a matter of fact, somebody tried to call me on this, at Atlanta last year. I think Kai Strand or somebody, “Russell wasn’t so and so, Russell wasn’t so and so,’1 you see, and he came through on his way to Mt. Wilson, and there’s something else in that paper. This is where there’s a table showing the second coordinate. It was just absolute magnitude before, you know, had just been published, and the luminosity of super giants were still at zero absolute magnitude, you know. Did you know about that? Epsilon Aurigae. Well, look at the calibration. And this is where the case was made. This was really the medium for the whole Yerkes classification of spectra, you see. Just let me see here, I think I can show it to you. You see it there? Log g is constant. It sure looks a heck of a lot different from the ordinary HR Diagram. This is ancient history. This has no interest at the present time, you know, at all.
Yes, But it has no interest at the present time, you know, none whatever. All right, now you see, this is a case. In my innocence, I thought everybody would be very pleased. Russell saw this. Now, you see, here are the different times, the Mt. Wilson publications, and the luminosity they give for a certain star. So you’ll find a super giant, like the North Star cF7, was +0.6. Then it goes up to —3,0.
Those are different calibrations,
Different years. But nothing in the star spectrum changed. So Russell said, “Oh, this is great. I want to tell Adams about this.” You know the thing that happened?
Adams wrote Struve, my director, to tell him to tell me to get me to lay off of that stuff.
That’s what happened. Oh, you’re right. (laughs)
What did Struve do?
He told me. That’s how I know what I’m just telling you.
So, you certainly continued working on it,
Of course. But the point was that Adams was not overjoyed. Because it was criticizing Mt. Wilson work, he thought, you see. Here is the crux, on one page or so, of why the Yerkes classification, the NK classification, was developed, right there on that page, The star didn’t change in between,
But the values did.
This is the question of the numbers again, you see.
Yes. Now, that’s because the calibrations were different each time?
Sure. Look, if your calibration curve doesn’t go past zero for high luminosity, you can’t get a star brighter than zero. Even if they go up to — 8. Now that looked pretty obvious. But all I did, I stirred up the animals. I managed to make it to Mt. Wilson in 1948, and had a nice talk with Hubble, a few people, but of course, it’s all different now. I mean, it’s all historical. I just dealt myself out of the community, by that thing.
Well, how did Russell feel about it?
No, Russell was completely different. He came through and said, “Oh, I must tell Adams.” He was interested. It was a positive reaction he had to it. Not negative. Positive. He was enthusiastic. His enthusiasm was his great, great point, you see. I never had any trouble with Russell at any time, But he was really enthusiastic, this was the thing he was really excited about.
And he didn’t think Adams would react to it negatively?
I don’t think so. No, of course not. He wasn’t saying, “Now, look, I’m not sure that they’ll like that out there.” No, Just the reverse, as far as it could be to the reverse. Excited, enthusiastic, positive, “I must tell Adams about this,” you see. Ahah!
That’s very important.
That’s when I began learning the facts of life, The astronomical facts of life. Somewhere along in there.
But you always had Struve’s support?
I had, scientifically, yes. I have to say now, I have to tell you one of the other things, I must mention this and then it’s time to stop, for now, You see, I owe my start in the whole field of spectroscopy, which has been my life in a way, to Struve. But all people are different in the course of time and we did have differences. In fact, there’s a paper Struve wrote in 1935 on the classification of B stars, This is just after I had written one on classification. It may have been just after that. But anyway, it was on the B stars, and in it, he makes a number of statements. Well, within a year Russell, Donald Menzel and Cecelia Gaposchkin jumped on him with both feet. That’s the only paper Struve ever wrote in spectral classification, And you might look at it some time.
It’s an interesting paper, but it violates some established rules, It’s a useful paper. In it, he describes what he calls Giants and Dwarfs, by, among other things, the intensity of the Balmer lines. From a certain intensity, a certain number equivalent width, a star moved from being a Giant to a Dwarf or a Dwarf to a Giant, With a change in spectral—type of course the thing has to change, because the Balmer lines are sensitive to the temperature, you see. And in it, you see, he had some stars that I knew darned well were Super giants, HR 1035 and HR 1040, they’re up in Camelopardalis, they’re somewhere around B8, B9 to A 0 Super giants, very definite Super giants. They were known for many years, you see. And you’ll find a note, in Struve’s published paper, “Dr. Morgan called my attention to the fact that so and so are usually considered as Super giant, but if we take this line of reasoning...” Well, obviously, the line of reasoning was too wooden, was not sufficient. The way he did it was not sufficiently discriminating, and actually, that’s the only paper on classification he did.
And so when this Struve volume was being published after his death, they were going to reprint that paper, which they did, and I was asked to write the introduction to it. I wasn’t going to do this, but I wrote a short introduction. Well, if you look you’ll see the conceptual part of the thing. It just leapfrogs over a certain region in the conceptual development that you can’t leapfrog over. And Struve said, “Well,” he said something about, “If two stars have so and so — it goes this way.” And Russell in his might and Menzel and Cecilia, I think all three of them were on it, said, “Well, of course, everybody knows, so and so and so and so, and all that we need, in addition to the Draper type is ... we don’t need more than that if we use.. .“ and these are the words, “a liberal admixture of the letter p.”
Who said that?
Henry Norris Russell, in a paper. Their answer to Struve’s paper. It has been 40 odd years since then. I don’t believe in that, you see. In fact I’m trying very hard not to use p for anything in the Spectral Atlas. It’s difficult to use.
For the record, the Russell paper is where?
“Classification of Stellar Spectra” is the title of the Russell paper, Volume 81 of the APJ, in answer to the Struve paper on spectral classification.
Yes. (break for lunch) It’s after a break for lunch and a very interesting period with you in your home. We had finished up just before lunch, we were talking about the 1935 paper on Classification, and the criticism of it.
It’s worth looking at just to see how dogmatic the criticism was. Not that in the sense that it wasn’t justified, but the dogmatic attitude toward what was considered spectral classification in the 1930’s by a man as distinguished as Russell is a very interesting thing too, you see.
Yes. That’s quite important. Let’s center then through the thirties, and start with your 1935 paper, “A Descriptive Study of the Spectra of A Type Stars.”
That’s the big thing.
You realized here for the first time that the abundances were very important.
Yes. This is descriptive with the emphasis on the word “descriptive.” The pictures show the K lines very, very different in two stars of the same spectral type.
Now, in this ‘35 paper, you recognized that there were A stars with peculiar spectra that had previously been thought to have been produced by composite bodies, but you showed that they were not.
That could be. Yes. And also in the YERKES SPECTRAL ATLAS and even our last one is a case where you have what looks like a composite K line, a broad shallow K line, and you think that’s a G star and an F star together. And as a matter of fact, these are strong strontium stars. They’re also magnetic stars. And in no case, as I mentioned on one of the new pages in the ATLAS, at no place does it seem possible to account for these in terms of two different stellar bodies. Other things don’t hold up. Now, that may be questioned by some people, but that’s all in the future. This is terribly important for the future. Because here is where the context of spottedness almost has to come in. And also periodicities. And while Horace Babcock has a few remarks about this diffuse K line coming and going in one of the stars, and that’s in ASTROPHYSICAL JOURNAL SUPPLEMENT No. 30, the surface of the problem hasn’t been scratched. The descriptive study hasn’t even been scratched, because in the case of the sharp lines, the notation has been considered only for this in particular.
The helium star a Centauri, normally has very strong helium lines, but they almost disappear, some of them, in a period of around nine days. But in the case where we have the broad K lines only, simply the breadth of the K line alone — remember, there’s no stellar rotation effect that affects this appreciably because you have sharp lines in the spectrum — it’s hard to see how that could originate. It looks as if there’s a gap. It’s not a continuum between a high temperature phenomenon and a lower temperature phenomenon, but it’s a relatively high in A type stars or early F, and then something that goes with a G or K star, namely, the broad filled in K line. So if it is really one stellar atmosphere then, not only the fact that something is varying, as it does in many of the other spectrum variables, but the question of spotted ness and the nature of those spots is important. If it is spotted ness, first of all, then, there is a very interesting problem connected with this. There was a time when I felt that it would be interesting to study this. The largest number of M variables among the brighter stars are these irregular or semi—regular giants, not the long period variables at all. You know, there are a dozen of them visible with the naked eye, g Hercules and Alpha Hercules in a sense, and a number of others.
It would be interesting to see if one could get a rotation period, because they vary with relatively small amplitude, a magnitude or less. But now the thing is, suppose it’s due to spotted ness? This is the question. They’re later than the sun. The surface brightness is lower than one would imagine it, possibly the spotted— ness would be over a greater area, all right. Now then, the thing is, suppose the spot was at a certain longitude. You get a certain period from it. But suppose that spot disappears and spots come up in other longitudes. You’d have a zero point shift. The period would remain the same, but your effect would be changing all the time. Well, I never was able to get into that and to do it. I think it’s a terribly important thing still, although some other people feel differently and may be working on it.
Although some other people may be getting that directly (although I don’t think so), the thing is, it’s terribly interesting and it seems to me that there are ways of getting it. And there are still particular ways it could be applied still. One wants to be a good observer and use his good judgment and self—discipline.
Why didn’t you follow it up yourself?
Well, I was in other areas. I can’t follow up everything. When I do anything, there are always a dozen things to follow up. And the one criterion that I use and that I still use (this is one thing that may seem unrealistic): I refuse to do busy work — just to do something because it is easy to do, unless it’s strange and unless it may even fail, even at this present stage I’m in, I’m not willing to do it. I have an application in to NSF, and now approved for the SPECTRAL ATLAS, and also one in for the cD Catalogue — this catalogue of super giant galaxies that were discovered here around 1960. Super giant galaxies — much larger than anything — the largest single optical structures that we know of in the universe.
This Catalogue is extremely difficult to do. It’s a complicated problem. So when you mention all these other things — there are many, many things that are nice to do. First of all, it has to have morphological significance and phenomenological significance. Note that I did not say physical significance. It implies physical significance, of course. But morphological significance for me — in particular seeing how far one can develop and increase significant morphological resolving power and resolution in two—dimensional diagrams and other things. Because I feel that in that sense it then would be a continuing kind of an effort, which has been over many years, and where the cumulative effect means that I am somewhat more efficient at doing that sort of thing that’s changed into something else and I think that these methods are basic to every sort of thing that is going to come out in the future. So this is what I prefer. But that other problem, you know, is also very attractive.
Could you have done it in the thirties? In the 1930’s, you were moving in that direction.
Yes, but what did I do then — as you can see from that paper you have in your hand there? It was the departure from work on individual stars and small groups of peculiar stars, into the general two—dimensional arrays which one had, in both coordinates, to work with non—numerical approaches. And that was a full—time job.
That was your 1937 paper on two—dimensional arrays?
Yes. And it took me six more years until the ATLAS was published. Very little was published during that time, and as a matter of fact I remained an assistant professor for seven years, and eleven in the two lowest ranks. And if it had been the present day, I would have been out in seven years and would have never attained tenure at the University of Chicago. In those days I was a non—tenured person for eleven years. Seven years in this period we are speaking of when I was working on the SPECTRAL ATLAS with very little other publications. I was promoted to associate professor and got tenure the year the ATLAS was published — 1943.
Then tenure was due to the ATLAS?
Oh sure, yes.
But wasn’t it evident to everyone here at Yerkes that you were developing the ATLAS through these years, and that it would appear?
Not when you are merely developing something. Looking back on it, we see order in the past. We can perceive order in the past. But it is almost impossible to perceive it when one is in the past.
Can you recollect really what your thinking was at the time in the directions of your own research? Did you know that you were going in the direction of an Atlas?
The only evidence on that is how that 1937 paper reads. You can see yourself there what happens after that. I cannot give you, though, processes in between.
You certainly discuss the advantages of two—dimensional classification in there.
Yes. I had this little note on the M dwarfs, the little stars that had no dispersion in the bands, except between the emission M stars — the Me stars — and the non—Me stars. It was so narrow that one could get good spectroscopic parallaxes from a visual type alone — in the visual region. And that was part of the general situation. I cannot reconstruct anything more than that. If you look at the 1937 paper, you will find that it is rather detailed. You will see several things developed there which rather clearly lead to what happened later on. But that is as far as I can go. I don’t want to superpose later order on what happened then.
Let me ask you about your recollections of that general period at Yerkes Observatory. You acknowledge Strömgren for reading the manuscript of that paper. You discussed Russell’s input, which is quite interesting. You also acknowledge Kuiper giving you masses for Omicron Eridani. Now, both Strömgren and Kuiper at that time were deeply involved in the theoretical interpretation of the HR diagram.
Kuiper was doing almost the most important observational work of his whole career, because you had that temperature scale of the stars, and the bolometric corrections of ‘38 to ‘40, in there. And those two classical papers, and also a large observational program at McDonald. In the case of Strömgren I acknowledge him for reading the paper. That’s the polite thing to do. But there was very little interchange with Strömgren. Not that I respect him less for he was a friend. In the case of Struve, you didn’t mention that I did not acknowledge Struve. I’d forgotten. I guess I didn’t. So anyway, then until Struve, you see, left in 1950, and you know, we had friendly talks on occasion, but it never was the same thing. And later, when I was in the hospital in 1952, he wrote me a letter, “Dear old friend,” something of the sort, very warm, you know. He was a warmhearted person.
But then he had his big disappointment, when he had gone to Berkeley and was satisfied to settle there and everything was going well, but then he took the directorship of National Radio Astronomy Observatory. This was the tragedy of his life, there. You know more of this than I do, I don’t have original sources in this. But he got in a lot of difficulty there. He had bad advice, and he insisted on a certain order of things, doing certain things. In effect it was considered a failure, his administration there. Furthermore, he was not a young man any more. He was born in 1897, and so in 1960, for example, he was 63. Well, anyway, in the last year or two of his life at the IAU Berkeley meeting in ‘61, he was a broken man then. When he left National Radio or Greenbank, he was a broken person. Earlier, I was out at Pasadena, working as a guest investigator there, and Jesse Greenstein had picked him up. He was actually almost in financial want, it looked like. Struve’s voice had changed, you know. We had lunch, and I could see he was just a broken man completely. This was about ‘58 or so, I don’t know exactly when. But he was very warm. He sent me a very nice inscription in his book ASTRONOMY OF THE 20TH CENTURY just before he died.
He sent you that copy? (on Morgan’s shelf)
That’s right. That’s the last thing he did before he died. Then, there’s something else that has to be mentioned. This is scientific. The basic thing was — and he recognized this after starting out — that he was the inspiration really and really the guiding person for those first early years. I ran the spectroheliograph and I observed on the parallax program.
The spectroheliograph program and the parallax program, other things, too, in those early years.
You ran these programs in the thirties?
Yes. I guess I was working with Moffat on the parallax program but I had full observing time on it. G. W. Moffat, he’s dead now. But the thing was that Struve and I both recognized, I think I can put it that way, that while we were both astronomical spectroscopists, stellar spectroscopists, that our way of looking at these things and our particular interests were somewhat different. And it’s lucky that I had the courage and determination to follow my own interests, because it’s clear to a person who reads our papers that they are different, in this sense: one can say that his papers are the more realistic, in the sense that they treat both observations and theory, because always it was a question of testing a theory or establishing something of the sort. And that’s the way physical facts are determined. I recognized that. But I was not fitted for it in the first place, by preparation, and also, I gravitated into what one might call the pure phenomenological approach or a posteriori approach with time, and I liked it so well that I stayed in it.
You’ve been describing your philosophy, the phenomenological approach.
And it does not agree literally with Struve’s. We respected each other. Don’t mistake that. As scientists, we both respected each other all the way through.
You mentioned just a few moments ago that it was 11 years before you were promoted.
Well, I’d gotten raised from instructor to assistant professor, before I got tenure.
But during this time, was there any pressure to produce more or do different kinds of work?
Well, as far as producing more, I’ve never had that. I have never appeared to be inactive or little active. That’s just not the sort of thing. As far as changing fields is concerned, I respect Struve very much. He never attempted to get me to change fields. And actually, that is the saving thing. If I had had pressure, and I know other people getting pressure even these days on that sort of thing, if I’d had that sort of thing, something would have happened. I don’t know what I would have done. But past a certain stage my work was a progressive effort, as I’ve said. Looking back, it was progressive, but I wasn’t conscious of it at the time. But I knew what I wanted, the kind of work I wanted to do. I could see these other people. Struve was just terrific, you know, brilliant, bringing these people, Kuiper, Chandra and Strömgren. This group plus Struve, in the years just before the war, was sort of a Brain Trust, you know.
Kuiper, Chandrasekhar, Strömgren?
Strömgren went back just before the war. They’d meet at Struve’s house, you know, and it was a very elite group, and every one of them went by me. Except Struve. The other three came as assistant professors and they went, zoom, you see. And that’s the way it should have been. They were all more able, far better prepared and more able astronomers than I was. There’s no question about it. If you’re willing to call what I have done astronomy, it’s a very specialized kind of astronomy. It is not a general overall type of astronomy. These men were all brilliant, very good indeed. I was not in that group.
But you were tackling an extremely difficult and potentially very fruitful problem, in calibrating spectroscopic systems against photoelectric systems at that time.
Looking back from now, what you say is true. But it was not clear to my associates at the time that it was true.
They did not see this?
No. I was in a lower category from these people I mentioned a moment ago. I helped. I urged Struve. See, he was afraid. He was quite sensitive about being foreign, you see, I can’t remember the order of these people. Chandra came in a January, and he went back to get married. He just visited here in a January. I took him out to lunch, I remember that time. He got married and came back probably that fall. I can’t tell you the order. The president of the University of Chicago was very strong for Struve, and he wanted these things. But I was the one who pressed him very hard. He said, “We can’t have two or three foreign astronomers come in here, in addition to myself.” It was like that at the time, you see. This was in the Depression.
Who said that?
Struve. He was sensitive. This was the Depression. There wasn’t a lot of money around. It was rough. This was the middle of the Depression. You can get it from the records. Barbara Perkins has the catalogue of all these people, you can probably date their arrival and everything else if you want to from that. But anyway, I was the one who pressed him to go ahead, I know, very strongly, with Kuiper; to forget the foreign part, we wanted the best people, you see.
What about Chandrasekhar?
What about him?
From some of the records I’ve seen, it seems it took quite a while for the university to decide to bring him here.
I’m not aware of anything of that part. You see, I was taking care of the observatory on the day by day thing, but I did not see official communications at all. I have no idea about that.
When Kuiper came and began working here, what was your relationship with him?
Well, I respected him. Actually, I don’t know whether he had a continuing position at Harvard or whether it was a temporary position, but he was at Harvard. I wasn’t in his class, in a certain sense.
Was that his opinion?
That’s my opinion. But I got it from him, this opinion, from being around him.
I see. You didn’t really do any work together.
I’d like to know more. Could you bring up the discussion that we had at lunch, about Kuiper’s treatment of Wesselink?
Now, this came from Wesselink, and you have to get this information from Wesselink, because the details of it may not be correct, what I remember. But if you have Wesselink, there certainly must be something about it, because it certainly was an important thing in his stay here, see.
Well, the fact that you mentioned it really caused him to go back in disgrace, was this evident to Wesselink at the time or Kuiper?
I can’t tell you that. Kuiper, I don’t know whether he ever knew it. I don’t know.
Did Kuiper treat other people this way?
No. He was not stern, disagreeable or bossy in general. He had some people he cared for very much. You know, he was very close to some people. I could put it this way. The thing that meant the most to Kuiper was: 1, his getting the equipment that was needed for his work; and 2, carrying out the programs as efficiently as possible, and with the help he needed, with the point of view that his programs were tremendously important. Everyone has a right to feel that. But perhaps for him it was even more, so that that would even overrule some of the more soft interchanges and general lightness of social behavior. I think I’d have to put it something like that. No, I respected him very much. And he was a great astronomer. He has had nowhere near his recognition, nowhere near what he should have had.
Let’s return again to your research in the thirties. In 1937 you had a note on “The Effect of Recent Increase in Brightness of Gamma Cass.” That’s an interesting little note.
Well, you see, I spoke to Struve. I couldn’t do anything about it. I didn’t have the equipment. But I just thought somebody would feel it was worthwhile following this thing up, you know. But there was never any reaction to it. Nobody ever did. Of course, the time has passed, you know. There’s a certain light time relationship. It’s a simple thing. But it would be an interesting experimental opportunity, to know that something was going to happen in the future that one could prepare for that had actually happened in the past but could be observed in the future, you see.
But you couldn’t predict it?
No. Not the time it happened, not exactly, except it would be in the future.
Right. That’s very interesting, this light time would yield a true separation.
It is surprising that no one followed that up.
Well, you see, the thing is that people were all doing their own work. To be perfectly frank about the thing, at that time, I did not have a big reputation at all in astronomy. Just didn’t, you see. That’s all there was to it.
Do you think the observation might possibly have been made if World War II hadn’t intervened and closed so many observatories?
Possibly, if anyone had taken the trouble to do it,
I see your M Dwarf paper and your study of titanium oxide absorption came in l938. And also in ‘38, you wrote a paper on the determination of color indices of stars, from a classification of their spectra.
Now, this seemed to be an extremely important step.
I think it was.
Again, in hindsight?
Right. That’s right. This had its origins, almost certainly, in Opik’s Tartu papers, the beginning of this line of thought.
In Opik’s Tartu papers?
Yes, on color indices and things of that sort.
Could you discuss Opik again?
I can’t. You see, the point is, I have forgotten the details of this.
But you mentioned of course, at lunch, that he is a very underrated person.
But he’s beginning to get some credit now. For example, in astronomy the yearbook, THE ANNUAL REVIEW, he’s got a long chapter there, which is reviewed at great length in the last SKY AND TELESCOPE. It’s a completely different kind of thing than they ever had in there before.
It’s written by Opik on his own work, is it not?
You should read it. I haven’t read it in the original. I read part of it in SKY AND TELESCOPE.
I see. Yes.
In fact, I’m looking forward to reading it very much, you see. Right now I’m in an endurance contest to get this Atlas finished. I have got the money to pay for it from the National Science Foundation, and before inflation takes it out of the range of the money I’ve got, it’s got to come out within the next few months. And I have not kept up in other fields in recent months, either. The last six months, because of that. But the early Opik papers have a classical beauty about them. Incidentally, suppose that you survey a field for new proper motion stars, and you find a certain number. Now Opik was, I think, the first person who did this in one of the Tartu papers. You have a second survey, independent survey, and by simple, very simple analytical development, you can correct and get the total number in the field, from those two things. Did you know about that?
If the two searches are independent.
Independent. Incomplete and independent, you see. It’s a very neat paper. Now, a lot was made out of this. Someone else talked about this years later, maybe ten years later, I can’t tell you where.
The original Tartu papers were pre—World War I?
Pre—World War. I would like to look that up.
But he was publishing certainly pre—1920.
Yes. Of course. Yes. I can’t give you the dates. I don’t want to even give you the decade for these things, because I don’t remember.
How did you come to read them, if they were so esoteric? How did you become aware of Opik?
Well, I don’t consider them esoteric. It’s the way they were dealing with observations, because he only had little telescopes and so on. It was his certain methodology, dealing with color indices and such things, within a more precise conceptual picture than other people were doing at the time. But that was not popular in those days. It’s only recently, in later years, that this sort of approach is being taken. So I don’t think it’s esoteric. I think that it was very valuable but it was not spectacular work.
My question was, how did you become aware of this work?
Well, I just used to read all sorts of things. That was the beauty of the Yerkes library. And it attracted me, when I first saw them, as certain other things attracted me. And that was one of the ones that attracted me very much when I saw them.
Let me ask you a few questions about the 1938 paper on color indices.
I don’t remember that very well. I’d have to get out a reprint of it to remember it.
You discussed Bottlinger’s photoelectric color indices.
Now, at this time Stebbins and Whitford were actively developing photoelectric work.
But it was narrow baseline work. The baseline between the two colors, to get the color index.
But Bottlinger’s was different?
Bottlinger’s was. He was an extremely fine observer, and I believe the baseline was somewhat larger. The number of stars was as large though of different kinds. Stebbins and his collaborators worked usually on early type stars, except for the M stars, the giants.
Right. They had the big B star program.
That’s right. But regarding the Bottlinger work — the question is whether one recognizes its value. He was already dead, he died quite young, I think. I don’t know when it was. Conceptually, the way the thing was set up and done, and the quality of the results, was better than anyone else’s work that I was able to find. Now, Stebbins’ work was very good. But his Cl band was very narrow. So there was no change at all from about AO to the middle F’s as the Balmer lines drop out. The Balmer lines cut a lot out of the violet and as they drop out the metallic lines do not intensify strongly enough, the violet lines, to where you have an almost horizontal relationship. Hertzsprung found this sort of thing using photographic plates.
Yes. If you don’t use a red point, where this is minimized, you find this all along. It’s very insensitive for color index, in the region from the maximal hydrogen, which makes a star look abnormally yellow there. And as that fades, it blues it, at just about the rate that it will redden it from the metallic lines coming in.
That’s very difficult.
But Bottlinger was absolutely outstanding. His work was outstanding in quality and that’s why I used it. I couldn’t say that, I didn’t want to compare it with other people, but that’s the reason.
You found very little dispersion in the color index studies that he did, and your classification.
Yes. But this was before MK system.
But this was working in that direction. Did this get you interested in photoelectric work?
Well, not observationally. I never have had electronographic experience. I was not a laboratory type person in physics courses. I did what I have to do. I had no training and I never did. I never have observed with a photoelectric photometer, even a UBV photometer, and this is why without the willingness of Harold Johnson to collaborate with me there would not have been any UBV system. There had to be the observation and Harold Johnson was the ideal person to do the work.
I taught a course in photographic photometry for a number of years here, and this was on methodology. We covered technique in photographic photometry including prism crossed by gratings and things of this sort. I knew those well and I taught them and I actually did a certain amount of work that way. But the most important job I ever did with it was a complete flop. We had a little six inch reflector, a Newtonian of all things, mounted on the old Bruce instrument down here. There was an objective prism for that, and the shop made a wire grating for it to my design, with a certain spacing, so as to throw out the spectral orders. You get a spectrum down the center. Then you have others parallel on each side, only they aren’t parallel because the dispersion comes in and they bend out to longer wavelengths, you have a family of these.
Is this a “grism”?
I don’t use the word. The word is absolutely anathema to me. can’t stand the sound of it, It sounds like the leavings of the Thanksgiving turkey the next day. (laughter) Anyway, this goes way back. I didn’t invent the method at all. But anyway, this was to go to spectral photometry, to get a monochromatic system of magnitudes, and this was around 1930. I was dissatisfied with the international photometry, you know, integrated photometry, and the spectral photometric things. There were very few at the time. This is way back.
There were the large systematic errors you were talking about.
Yes. Well, that’s integrated light, but also the others. There was nothing in the red that was much of any good. What I wanted to do was to set up monochromatic photometric systems, just particular a point. The prism obviously is unwidened, you see, and the prism was to give the spectrum. The grating was to give the scale. So I had, by the old Abelian function the delta U and delta N, a certain constant of N, in terms of a family of delta S’s, which are whatever you’re measuring, a deflection or anything else like that. It goes back to the Abelian function of the 1850’s or something. This is what F. H. Seares used. This is the way Seares and others did for the North Polar sequence. All right, so then I had, with the prism crossed by grating, shall I draw a picture or do you understand what I’m saying?
Can we put this in the interview text?
Sure. So here, of course, down the middle we have a spectrum, like this. Now we have a crossed grating with the interval such, the A plus D interval, that it throws the spectrum out to a convenient distance, so we can measure these things without having scattered light from one thing or another. Then we have a pair on the other side, like this. Then we have others, like this, this sort.
The dispersion goes along these lines?
It’s the reverse of a prism. So, this is red out here, then, remember the grating throws out the red more. The red becomes more refrangible than the blue.
You want to label that Red?
You understand, one forgets things in 30 or 40 years when one doesn’t use them. The grating is the reverse. Anyway, so this is red, and this is violet, and here’s the zero order. Now, we know at any point, the Balmer lines if we want to. I had a point at 4200, and several points I was going to measure, and this would be pure monochromatic. There are certain effects, you know, differential extinction which is different with different colored stars, things of that sort — furthermore, I wanted to get red variables. The only way you can really get good light curves, photographic curves for red variables; their different colors and their comparison stars are different colors; where you have extreme color is to do it monochromatically. You understand?
Well, anyway, I spent a whole winter on that, one of the coldest winters of my life down here, and I had only one fundamental standard. What I did was work everything at the altitude of the Pole, to eliminate differential extinction from the altitude. In addition to that, on every plate, I had one star that was a fundamental standard, one that had a nearly continuous spectrum of all the bright stars. Do you know what that star was? Gamma Cassiopeia. Well, within a year of the time I finished this, Gamma Cass had brightened up almost to first magnitude, and it turned out it was really variable! This is worth putting in the record because of what I tell you now.
But the technique is interesting.
But I didn’t invent the technique. It was known before. But I was going to use it for all sorts of things in this paper you’re speaking about now. This is what I was working toward. But this is not worth the space on your tape. This is something that did not work out, completely destroyed, because I picked a comparison star that was a variable star, that had never been known to vary before.
Well, it is a worthwhile episode.
Sure. Fine, You’ve got to check this refrangible thing, it’s hard.
Let’s continue on. In 1941, you wrote a retrospective of the observatory. 
Well, a history of the observatory.
Yes, you wrote it. It was the one where you also wrote about the “Astronomical Struves” in SKY AND TELESCOPE.
Yes, I guess I remember a little bit now. What’s the date, what’s the year?
Yerkes Observatory, 1941, and some notes on the astronomical Struves, In THE SKY before SKY AND TELESCOPE came into being.
Volume 5, No. 8, yes.
1941. Now this was just at the time that McDonald was developing, the observatory.
Yes. It was in operation. It was dedicated in April, I think, of 1939, because it was just before war broke out, and the people just back from the dedication to Europe before war broke out.
Yes, right. And you discussed also the astronomical Struves?
Yes, I don’t know anything about that now.
But you were certainly on reasonably good terms with Struve to write this.
Well, we were speaking and we were doing business together. But this earlier part, where I was really inspired by him, and he used to come and talk at nights and all sorts of things had ended. It’s the difference between a close friendship and mutual respect and business—like working together, that’s what I mean.
At this time, though, as war was becoming more and more evident, that it was going to be breaking out, you were working on your ATLAS. But did you see a time when you would enter the war, one way or another?
Well, we’re talking about 1941, so I had a daughter who was seven years old and a boy who was five. I had a mother who had been deserted by her husband, my father. And I had a wife and myself.
When did that happen, the desertion?
Somewhere around 1930, ‘32, somewhere in there.
So you were well out of the house by that time.
Oh, I never saw my father after 1926. I went home Christmas of 1926. I never saw him again after that. I had many dependents, and in addition to that, I told you what Struve had said. I was tempted to take this, the order was to South Pacific. I can’t tell you what it was now. I don’t remember now. I was never told exactly what it was, the nature of it. It was to go somewhere in the western Pacific as a scientist. And I don’t know what it was. But I made the decision not to. As a matter of fact, the interesting thing was, I had not asked for exemption from the draft, you see. And it went on that way quite a while. I think that later, sometime in the middle 1940’s, I asked the local board at Elkhorn for exemption, from the point of view of dependents. I don’t remember whether I asked or whether it might have been made without my asking, simply from knowledge of what I was doing. But I did not ask for exemption in the beginning at all. I just let things go. Because at that time I didn’t know what I would do if I were drafted, but I simply couldn’t leave. My wife never was strong, actually, from the birth of our first child in January of 1934. She never recovered entirely from that. She was in an anemic condition all the time after that. And I had four dependents and it just seemed to me it would have been stupid of me to just take off. There was no one to take care of them. Her parents were dead by then, you see. Her father was dead and her mother was not able to, you know.
As the war progressed, more and more people here at the observatory left to do war work.
That’s right. Or did it here. There was no one else. Henyey and Greenstein were here, and Kuiper was in Germany. He talked a lot about rescuing Max Planck. I can’t remember. Don’t put the name down. Some famous physicist from Germany, in the time of the occupation or something. And he was active in some certain kind of work, I don’t know anything about it at all. Chandra was in highly secret work. It may have been at a place outside of Baltimore, I can’t remember the name. I don’t know where he was or what he was doing. He was doing very high level classified work, and Strömgren had just gotten back, after the dedication of McDonald Observatory, and was shut up in Denmark for the duration of the war.
Right. Now, there were other people here at the time — Thornton Page, Horace Babcock?
Page was not here during the war.
They were all on leave for war research?
Horace Babcock was here only a year, you know, just a temporary person. And Page was on the staff, but he did not have tenure. Of course, he was away during the war. He was up here a while, then he was on the campus a while, and I cannot reconstruct exactly what happened there. He had a terrific accident. He was a wild man in a car. He had the record for driving time from Yerkes to the Chicago campus. This was before there were any superhighways here. He would get to the Michigan Avenue Bridge in Chicago in less than an hour from here, and there were no superhighways.
Less than an hour?
That’s what he claimed. Anyway, he drove these little cars, and he ran under a truck. It just took the bottom part of his head out, I think, I can’t understand how. If it had been the top he’d have been killed instantly. He had 15 or 20 operations, and they finally got him put together, but he never was the person afterwards that he’d been before.
Is that when he lost the use of his eye?
Eye? It may have been damaged, I don’t know, but the main thing was that in the head he never was the same as he was before. He’s the son of Leigh Page, the physicist who wrote a famous textbook and he got his start from that, a reputation on that. He was a fairly good astronomer in the earlier days, but after that accident, I’d encounter him in various places in the world, including Moscow — and there just is a kind of dullness that must be from the operation.
Well, I know that the optical bureau here was very active — Henyey and Greenstein.
Well, actually, this is an interesting thing. The wide angle camera which doesn’t exist any more was built here, And that’s what we discovered those new HIT regions with. It was a 1400 F/2, but it was loaned up to Madison, by a former Yerkes director, by C. R. O’Dell, I suppose, and someone from Madison sent me a Polaroid picture of it. It ended up nothing but a spherical mirror in a ring stand in a laboratory up there.
They completely dismantled it?
Well, I don’t want this published anywhere and I don’t want this out. You can leave it on here if it’s not copied. Anyway, the genius behind that thing was Henyey. Greenstein, you know his record, he’s a good astronomer. Van Biesbroeck was a good astronomer. But the genius in that, the only genius, the only person with deep genius, was Louis Henyey. But it was never published. And the thing was that Henyey, also, as geniuses are, didn’t answer letters sometimes and things of this sort. And Greenstein said that he wrote a first draft of a paper on it and sent it to Henyey. Henyey never returned it and Greenstein said he was damned if he was going to write it again. Most places call it the Greenstein—Henyey camera. Again, you get the alphabetical order — but the person who did it, the genius, was Henyey.
What was Henyey like?
Well, he was from Cleveland. He got his degree at Case. I believe it was on an astrometric problem or something, not in the field where he became known. But he came here and joined the staff and, as far as I’m concerned, from what I could see, was the most brilliant man ever to be a member of the staff. With all the great names, he was the most brilliant. I will always remember a colloquium here, Chandra brought the daughter of C. C. Keiss, who was a physicist at the Bureau of Standards in Washington. He’s dead. His daughter, named Margaret Keiss (and she married Wasley Krogdahl later on), was his student here. She did a thesis under Chandrasekhar, and she presented it here at a colloquium. Now, this is the sort of thing that you cannot get out now, because these people are alive, those I’m talking about.
Anyway, this is just an incident. So she gave a colloquium. Henyey was at the colloquium. He asked a couple of questions. After the colloquium, someone saw Chandra. Officially the thesis had been put in the mail, to mail to the ASTROPHYSICAL JOURNAL. He pulled it out, and she spent a lot of time working on it again, because of Henyeys questions. So this is just an example. And Henyey was a great genius. His paper with the two guys who went over the hill to Livermore — this paper on stellar evolution — is THE great paper in the whole history of stellar evolution. To me. Now, not an expert in the field and you can pick someone else if you want to, but that was the thing where the meat and potatoes were. He even determined luminosity — absolute magnitudes. But he was a great genius. He was sort of a quiet person and he kept to himself. He was a very find chess player.
He was not the easy social type. I didn’t see him more than once or twice after he went out to California. I gave a colloquium out there one time when I was working at Lick. He died young and it’s a very terrible, great loss to astronomy. Guido Munch could have been as brilliant, but he had to live the Latin type life so he was working with two strikes on him the whole time.
Munch was here a bit later, a student of Chandrasekhar’s?
Yes. Henyey got his degree before he came here. But Henyey is the most brilliant person who ever went through, counting all the big names here, for sheer brilliance, Henyey was the most.
Who actually managed the optical bureau here?
In those days? In the war, this was completely secret. Nobody knew what was going on.
You weren’t really aware of what they were doing.
No. Listen, this wide angle camera was designed and constructed for the Air Force, I guess it was, to be used in exactly the opposite manner to its astronomical use. The light rays went in exactly the reverse direction to allow a person to see as if in a plane, simulated, all around him, for pilot training. That’s what it was for.. Now, somebody can describe that more precisely. Jesse Greenstein can tell you more. But this was a secret, We didn’t know what was going on. The place was locked, and they never talked in front of us about anything. Nothing.
Was there any other war work done here, other than the optical bureau?
Not that I know of. There was no one here to do it.
Nothing in the machine shops?
I can’t tell you. I didn’t have clearance. No reason why I should have clearance. I didn’t ask for it and there was no reason for it. I don’t know what was going on.
Well, during the war and just after, you continued work on a number of spectroscopic problems. By 1947 you began work on Population I and Population II kinematical studies. I’d like to know what your recollection is of this work.
I believe so. These were high velocity giants, you were looking at, spectroscopically.
Well, detecting them from their spectra from objective prism plates. But I was not actually working in kinematics as such.
But I’m interested in what your initial reaction was, if you can recall it, to hearing about Baade’s work in 1944.
Very impressed. See, I was the editor of the ASTROPHYSICAL JOURNAL from 1947 to 1952. During the war Baade was out in Pasadena. He was grounded. He was a German national and he had problems getting around but he got up to Mount Wilson. There was a blackout in Los Angeles and so the 100—inch, at the time of blackout, was really something. He worked to get the resolution of M—31, M—32 and NGC 205. Anyway, he sent that paper to the ASTROPHYSICAL JOURNAL when I was editor. And I thought so much of it that I asked permission to include original prints of the galaxies. The picture reproduction for it was not as good as I had hoped it might be, and I asked Baade if he would loan me a negative and we would make prints here, to bind in the APJ, showing it better, the actual prints. He sent the negative. We made them. I did those with my own hands. I made all the enlargements, all the masters and everything else on that, every bit of the photograph on that. And the prints were made with two high school girls along with myself, you see. So I had my lab where I was testing different fine grain formulae and all sorts of things and also photographic photometry. I was interested in it and taught it. So he sent the thing and we made the prints. The circulation of APJ was something between 600 and 800 at that present time. We made enough and it’s bound in the APJ, and he acknowledged it. The contrast is higher. It doesn’t show as far out, but it shows tremendously sharply, the resolution in the inner part, yes. I’ve always had tremendous admiration for Baade and that marvelous paper. This was a week’s work, long heavy work and very expensive to make that illustration better.
During that period also, during the war, the revenue for the APJ was very low because of the lack of foreign orders, and this was a very serious time. Now Struve was editor through this period?
That’s right. I was only editor beginning 1947.
But the Baade paper was ‘44.
Was it that early? Wait a minute, was it really?
The population study. Possibly this was the resolution study.
Wait a minute, I was not editor then. I talked Struve into my making the prints. He may have had me as referee or something, I knew about it. Struve was editor, but I made the prints. I didn’t realize it was that early. My crew was actually making the prints for the SPECTRAL ATLAS at the time, because we made 200. You see, we made two different sets, 200 at one time, 200 at another, I think, I think 400 altogether or something.
Did this paper and work increase your interest in galactic studies?
It must have. Actually this was a combination. The SPECTRAL ATLAS made it possible, so far as I’m concerned, for the first time to get good distances for B type stars. Now W. S. Adams and his people had methods, Adams and Joy. They had a paper on high dispersion spectra. On high dispersion, the Balmer lines look weaker in Main Sequence stars than they do in Super giants, because the wings do not show.
But we used low dispersion, the kind of plates that were taken in the years from 1939 to ‘40, really about 1940 for the best ones, although I was working a number of years before on it. A little spectrograph had been designed in the late 1920’s by Moffitt, and it was to get radial velocities for fainter stars. Well, they tried it out and it was unsatisfactory and they dropped it, put it away. There were six plate holders. tried it. Each plate holder had a different distance from the focal plane, that’s why they got poor results from it. We went to one plate holder, and made arrangements to move the plate along, and have the spectrum turned to the other direction, so we could get 15 to 20 exposures on a plate if we wanted. And then the development of these plates then showed very markedly that you could see differences among B stars, that simply did not show at all with the high dispersion, because of the wings of the lines. All right, then this was the development. This produced the result of the luminosity class step of the Yerkes Spectral Atlas, and in the plates taken in the years immediately after that, one began using it you see, to get distances of the B stars. And then we had Baade’s work on the stellar populations — he had three beautiful pictures. He sent me an original plate, you know, one of the first good plates from the 200—inch, with the Ross corrector in it. Sent me the original! When I was working on these things, you know. He was a marvelous, unbelievable person.
He was very generous.
This plate was reproduced on the front cover of SKY AND TELESCOPE, when we announced the spiral arms, that issue, a little section of it. But this showed the H II regions defining the spiral arms. So here we go to work then. First of all we get distances of the B stars, and in the years just immediately following that, start the wide angle camera survey of the Milky Way plane. We discovered that tremendously big — like a peeled orange — nebulosity around S Monocerotis.
Well, it’s an H II region, a great big H II region. And about half a dozen others were found right here, you see, and the same around Zeta Ophiuchi was discovered here. Because on the small scale, you could see low surface brightness things. And furthermore, the point was, well, “how can you use a polarizing filter for H alpha, when you have an angle of 1400?” We didn’t, because you have a lens up here, photographing the real image a few inches above the concave mirror, but the angle up here was only 260 for the 1400 down there, so you could use it all over, do you understand?
I see, the entrance window was quite far away from the mirror.
Now then, this was the thing that Sharpless and Osterbrock did also. Right, they took most of the plates. So these different lines then were converging, first the luminosity classes from the Yerkes Spectral Atlas. Second, the information Baade had on the populations and particularly the arm populations in M31. Third, the work in this paper with Bidelman about 1947, on the North Polar sequence and stuff. It’s a photometric paper. Nagun and W. P. Bidelman, “On the Interstellar Reddening in the region of the North Polar Sequence, and the Normal Color Indices of A Type Stars,” ASTROPHYSICAL JOURNAL 104 (1946) 245. That’s a short paper. But that was the beginning of the work that led to the UBV system. We have first of all the luminosity classes, we have the work of Baade and so on, but then we have the problem, the damnable problem of the interstellar reddening correction for apparent magnitude. And there, one has the narrow base line colors in which you had a factor of 6, at least 6 for the photographic, from the observed color to the other.
This is Stebbins—Whitford?
Stebbins had Cl and C2 both, I believe, in two given series. Stebbins, Huffer and Whitford, and one with Stebbins alone, I think, you can look it up. Strömgren has used Cl but other people have used Cl too. That’s Cl/T of long ago. So, it isn’t entirely the Strömgren area, you see. All right, so then the question you see, was, how to correct interstellar extinction for distances? I told you about this thing that Stebbins had found with his associates, that there was about a quarter magnitude extinction at the North Pole, you see, and that they were using intrinsic colors, the Draper Extension or something, and the intrinsic colors were too blue. They weren’t really AO stars at all. I told you about that this morning. So then this paper comes along and that clears that out. We needed a longer baseline, and we needed something defined in some other way than the North Polar sequence for color and magnitude.
You needed something other than North Polar Sequence?
Because there, in your guiding alone, you have a different kind of guiding, it’s perfect if your orientation is correct, while it’s never correct anywhere else. And the worst thing about it: the magnitude scale is a direct and almost smooth function of the color, and that means that you cannot separate color and magnitude for integrated work. You understand?
Yes, I follow that.
That’s why it has to be based on stars, and you have to have some other system other than that. And that’s how it started out.
OK. You started working with Jason Nassau also on this.
Is this basically because of the Case Schmidt telescope and its availability?
Yes. It was because of the objective prism, that’s right. As a matter of fact, he was always asking for advice on things. He asked for advice about plates and things of that sort and bending the plates and so on. I used to go there, usually several times a year, and initiated a survey, the most important thing, a survey for 0 B stars around the galactic equator, down to about the Henry Draper limit, to about 10th magnitude.
So I coined the name “OB” for a certain category, a two dimensional category which is defined, and here is the place then, the publication which followed that work. This is Volume 10, University of Michigan ANNALS, at a Symposium called “The Structure of the Galaxy,” symposium held in connection with the dedication of the Heber Doust Curtis Memorial Telescope, June 22—24, 1950. There was a meeting of the AAS at Indiana, and we drove up at the end of that for the dedication. All right, there are two papers in here, the one by me is a paper — the Natural Group paper which defines Then there’s a Nassau—Morgan paper “The Distribution of Early Type Stars of High Luminosity Near the Galactic Equator,” page 43. So here, it’s 33 and 43.
I’d like to talk about both these papers. Do you see them as two different aspects of the same problem, or are they quite separate?
The Natural Group concept is much more general.
I would say that, as a matter of fact, Malcolm Smith did that magnificent, what I consider the most brilliant observational job of the whole 20th century — the objective prism work in which he not only discovers new quasars, but gets their red shifts, from objective prism plates. The remarkable technique this man uses. He quotes the paper on Natural Groups for that. So the Natural Group thing stands on its own feet, and it’s just as valid today as it ever was. A Natural Group can also be a group of stars having similar extremely important spectral characteristics, even if they do not lie in a small region of the H R Diagram. For example, in the MAT Spectral Atlas, I show two Wolf—Rayet stars in Cygnus, and Gamma Velorum in the Southern Hemisphere, all of which show the metastable helium 3888, with a violet shift of between one and two thousand kilometers, each of them, which is like the satellite UV stuff. I like to put those in a Natural Group. Anyway, this is a detail. This is to me one of the nicest, one of the most satisfying things that I’ve ever done.
You sort of also —
I’ll now turn to discuss the work on distribution. Here’s the OB Group, you see, here in the HR Diagram.
You’re also looking at the minimum dispersion or lowest dispersion possible, for useful work.
That’s right. Now, the Nassau paper, you see, there is something which I want to mention here, I have to mention here. This is in effect Nassau’s paper. You know, I classified the OB stars we located, but I mean, it’s the kind of paper Nassau wrote. And I did part of it too. Now it doesn’t show any spiral arms, you see. Here’s the Gould belt. It doesn’t show any spiral arms. Nassau has never told me and I don’t know whether this originally was Nassau or Bok, but anyway, you see, there was a time when Nassau felt, I think, that he had not been given proper credit for the discovery of the spiral arms, because at one stage alone, the spiral arms discovery was made possible by the OB Survey at Cleveland.
Let me interject an important question here. Were you always sure, since let’s say Baade’s examination of H II regions in external galaxies, that the B stars and the 0 stars would give you the shape of the spiral arms, or that any high luminosity stars would?
Could it have been other types of stars? What finally convinced you?
No. The stars were blue stars, and the first hint was the H II regions. Then, a year later I had a paper with Whitford and Code, on the B type Super giants. That’s the only paper on the subject, the only complete paper I ever wrote. The other one was never finished, as I told you. I regret very much — this may have been built up from Bok, I don’t know — that Nassau felt that his name was included only by other people in the group that discovered the spiral structure of the galaxies.
But he certainly got involved in the work.
He certainly did.
You’re showing me now a SKY AND TELESCOPE from April 1952.
And there’s a front cover picture.
The front cover picture has a part of the outer arm of M3l from a 200—inch picture, by Baade. A red picture. You look at this thing here and it looks like the Orion Nebula loop, the Barnard loop of the Orion Nebula. And it turned out that from the distance of M 31, the diameter is on the order of 70 parsecs too! This object, this thing right here just intrigued me no end, because of the tremendous similarity with the Orion Nebula. All right, this is from the 200—inch. Baade sent me the originals. And he is the most unselfish man I have ever known in my life, to do this. He said that these were the first good plates he took of M 31 after the Ross Corrector went into use. All right, decided, is that thing there? And the points are exactly where they are on here. I haven’t moved that. That model was made in early December, 1951.
I’d like to photograph that.
You may if you want to. Of course, it’s suffered a little bit. But these are to scale. These are H II regions and they’re to scale, the size. Here’s one kiloparsec. Here’s the sun. Here is the Great Rift, which I interpret as a tilted thing of this sort. Nearby it looks big, and more foreground stars appear as you go out to Cygnus. All right. This is Scorpius, and the H II region around Tau Scorpii. And this is the inner edge of the spiral arm. This is the Southern Coal Sack, that’s the Northern Coal Sack. In Cygnus these are the H II regions, here’s an H region, here’s Orion, and these two are the two in Monocerous NGC 2244, 2264. And the others, we can give a name to all of them. All right. Now, the point is this. We simply confront this model with this photograph; remember they’re to scale. This is not the same scale as this. This should have been larger to have it exactly the same scale. By the time this came out, within a month of the time this came out, I was in the hospital completely collapsed, you see, and that was the end of that. All right, here’s another photograph.
This is under AMERICAN ASTRONOMERS REPORT, page 130.
Now, you see the Southern Hemisphere there where I couldn’t observe. You see the chalk things. They’re not on here. That’s before this was on here. The one at the left, the farthest to the left, is the Eta Carina region. Now, I didn’t have any spectra, I had nothing for the Southern Hemisphere, but I plotted it from the assumption that the Orion Association and the Car group had the same extent in the Z coordinate. I didn’t know anything about the work of Ambarcumian and Markarian at the time at all. Some people thought I was coming in late and giving a different name (stellar aggregate) to something that was already discovered (stellar association). You understand. All right, but the Z extent in Orion was about 75 parsecs. I took the Z extent of the stars Miss Cannon called plain B and BO in the Car association. And I moved the’ Car association to a distance where its Z extent could be equal to the Z— extent for Orion. I get a distance then of 2600 parsecs for the Car association. The present distance, that’s within the error of the best determination of the best distance at the present time still. All right, the next one down is in Centaurus. The next one around is Kappa Crucis, which shines through the Southern Coal Sack. And N 8 was observed here. So there they are. Now, here’s the identification, but they made a big mistake here, not a big mistake, but you see, they didn’t correctly identify the center of the arc. This is not the center of the arc. That thing is wrong. The sun is not out there, you see.
Oh, that’s the only mistake they made?
Yes. This identifies the different things, you see.
It’s just poorly drawn.
And this is something which, to me, is the closest to miraculous of anything I’ve ever known. Remember, there was no UBV system. There was no way of getting a distance determination other than correcting by the Stebbins narrow base line. And there were no good magnitudes even, because the Stebbins work were colors, you see.
For the tape I’m mentioning, this is a large model that you have on the wall.
That has not been changed in one iota. It has old longitudes on it. Except that once in a while I tilt back the Great Rift, which tends to turn over. But that thing there still defines more sharply both the Perseus Arm, the arm we’re in, and the inner arm is practically as good, although there just by the thickness of the association. Anyway, the remarkable thing is how sharply defined it is. Because later work has not upset this in any way. But obviously look what one could do, with UBV and with modern observations of all kinds. It should be much better. Well, anyway, look, I’m not handing it to myself when I say it’s miraculous. I mean, when I say it’s miraculous, it means it seems more than I could possibly do. I’m not handing myself anything. This is the greatest mystery of anything that’s happened in my life.
Did you build this model sequentially as the data became available?
No, it was built, and Sharpless and Osterbroek did their part in making it. Remember the H II regions are to scale on these things, you see.
Who built this?
Well, I bought this as a laminated piece downtown at the lumber yard, and the circles were ruled by Sharpless probably, and the pins I have not observed and I have not worked in this field for some time, but Roberta Humphreys is the best worker in this general field there is anywhere that I know of, extremely fine, and she has sent me a preprint of something, it is not yet published. This is a catalogue of associations, she’s got, stellar associations. I had included only the ones that have an early 0 star in them, that is, 04, 5, 6, 7. This is now, that’s what it is, all right. One plots those. This is logarithmic. Actually one of our students did the work on a computer. First we were going to publish it. I don’t know what I’m going to do with it yet. We’re going to work on it a while longer.
This is your work, not Roberta Humphreys’ work?
What degree of improvement do you think you have now, over your original model?
The main thing is the method. Here the methods are luminosity classes, the UBV system for accurate corrections for extinction, and good plates. A number of plates — these are not all my plates. These are Roberta Humphreys’. She used other things in the literature. I would say that, this is why I say this puzzles me. Nothing was left out of this. There are no omissions or anything. There was no handwork done on this.
On the original, on your wall.
Right. Now a very fine astronomer, W. B. Burton, who is going to be chairman of the department at Minnesota this fall. He’s from National Radio Observatory. He got his degree at Leiden. And he’s the one, in an absolutely classical group of papers, that has shown that the radio determination from the 21 centimeter of the spiral arms cannot be trusted at all. In effect, there was a symposium at Maryland just a month or so ago, and Roberta Humphreys went to that. And she said she went and asked people, even the Dutch people. They said, “No, you can’t believe anything from those.” The optical thing comes back, because of the model you use for the radio work. You have peculiar motions of large groups, large regions, you understand, and you have saturation effects. It was subject to saturation. Lew Hobbs gets saturation of these lines, you can get them in high galactic latitude, even. So the knowledge of the field and what this implies is far advanced. But the reason I’m taking the trouble to try to do this, present it in some other way, is because the optical determination has now become tremendously important to get, because of the failure of the radio work — the people going by models, the Schmidt model or anything else you want, to get the saturation effects. You know, they never got the Northern and Southern Hemispheres to match properly. I don’t know whether you know that or not, but they didn’t. And it turns out, with all respect, it’s a terribly important parameter. It has to be determined, it even has to be observed if possible, in terms of something else. It can’t be investigated in terms of itself. Because of these systematic effects, you see what I mean?
I’m not going to work on anything that doesn’t have strong implications for the future. There’s no point. I’m not interested in seeing my name on publications any more, can’t you see. I talked Treanor into entitling this colloquium which was held at the Vatican a few weeks ago, which I did not go to, “Spectral Classification of the Future.” You understand?
And all these things, unless there are implications for the future, there’s not time left to mess with. I wouldn’t mess with just the “make work” type stuff. One more thing. The importance of the optical determination of the arms, both from H II regions and from early type Super giants and possible later M Super giants if we can get enough stars over great distances, this is now come back into terribly great importance. We were read out of the field, practically, in the middle 1950’s when the radio people were getting more detail clear on the other side of the galaxy. And in fact van der Hulst — who discovered or predicted the 21 centimeter line — in a symposium down at McDonald Observatory a few years ago, stated categorically and simply that the spiral arms of the galaxy were discovered at the Leiden Observatory in 1953.
Hm. Did he say that?
The exact words. Now, I’m not going to stir anything up, he’s alive. This is not to be published under any circumstances. He was pleasant. He was friendly and expansive a few weeks ago at Madison. I didn’t think much of the guy after that, but Oort thought the same thing.
Were his statements published from this conference?
I don’t think it was published. Oort has a paper, though. He wrote and asked, this was years ago, he asked if I had a copy of the plot that I had or something of the sort. And he published it I think in MONTHLY NOTICES. Oort wrote a general article on the spiral structure, and you can look in that and see.
You mean he implies priority too?
No, I’m not saying that, No. You have to see what he says for himself. But I heard van der Hulst with my own ears say this. Leiden and other results and the Southern Hemisphere, using Schmidt’s dynamical model. Other problems came from interstellar absorption — if space is transparent to this. And the third thing, did the stars and the gas, in this case the gas, have the same kind of order as a good drum and bugle corps or card section that spells out names on a Saturday or Sunday afternoon pro football game on television? If each little thing knows exactly what it’s supposed to do and does it — OK. But those conditions turn out not to be true.
Right. I understand that. Let me ask you one thing about the late fifties. In the late fifties, Bok and a few others criticized the radio work of Kerr and others.
Well, he criticized my interpretation. They want the circular arms, because of Lin—Shu. So, you had a Cygnus—Carina arm, he went around like this to Carina, a circular arm. I think it’s in his books, several editions of his MILKY WAY book.
Well, the point is, there are no discriminates of spiral structure for a full kiloparsec, in the direction of the inner arm. In the direction of Carina, it’s practically two kiloparsecs. While one has a continuous sequence out, over three kiloparsecs, for the Orion. Now, they have different ways of doing this. Now they call the thing we’re in a spur — Orion Spur, it’s not an arm. Why? Do you know why?
Because it has a tilt, too high for Lin—Shu. You understand? No, that’s the real reason. That’s the reason they give. They try to explain it away, and then get a circular arm, by running whatever is the solar arm. But the point is, you see those arms, you see how inclined they are there? This last thing I showed you confirms completely the high inclination of the arms. This is on the order of 20 degrees, you see.
Yes. I’ll have to go and take a closer look at that. Because you can only see it in perspective.
Anyway, it’s more than the six degrees or so that they want.
Yes. But he also criticized Oort’s interpretation.
I don’t know about that, has he?
At about that time.
I don’t remember that.
He felt that they’d found too many arms, that they were looking for too many things.
Well, you know, a good question for a doctor’s examination is, “What is the distance from the galactic center of the three kiloparsec arm?” And the answer is, about 4½ kiloparsecs. Nobody knows it’s an arm. You compare it with the other arms; all you do, you get a certain velocity and a certain intensity for 21—centimeter.
(Note added Dec. 1980): There is now no doubt in my mind that this was the thing, the happening, that set the direction for all creative work I have carried out, from 1928 to the present.
APJ 66 (1927) p. 135.
Pop. Astr. 35 (1927) p. 490.
Pop. Astr. 38 (1931) p. 466.
Journal of the British Astronomical Association.
”A Descriptive Study of the Spectra of the A-Type Stars” Yerkes Observatory Publication 7 (1935) p. 133.
APJ 104 (1946) p. 245.
APJ 117, 313, 1953.
Basic Astronomical Data (Stars & Stellar Systems Vol. III) Chapter 11, p. 204.
APJ 117 (1953) p. 313.
”Some Characteristics of Color Systems” Astrop. J. 118 (1953) p. 92. NOTE: This paper has received 32 citations in the Science Citation Index.
First author is Johnson so no citation study was made.
”Some Characteristics…” See op. cit. ref.
See: AJ 68 (1963) p. 288; AJ 69 (1964) p. 145.
APJ 73 (1931) p. 104; 74 (1931) p. 24; 75 (1932) p. 46.
APJ 77 (1933) p. 330.
APJ 117 (1953) p. 313.
APJ 77 (1933) p. 291.
Yerkes Obs. Pub. 7 (1935).
APJ 85 (1937) p. 380.
”Struve’s Approach to Spectral Classification” in Spectroscopic Astrophysics (G. N. Herbig, ed.) U. of Calif. Press (1970) p. 25.
Op. Cit. Ref.
The effect of “sunspots” on the stellar surface.
OP. cit. ref. APJ 85 (1937) p. 380.
W/ Keenan and Kellman (U. Chicago 1943).
APJ 87 (1938) p. 589.
Miss Perkins has been an administrative worker at Yerkes.
APJ 86 (1937) p. 100.
Op. Cit. Ref.
APJ 87 (1938) p. 460.
See figure on next page.
The Sky 5 (1941) #8.
Leverrier and Levee.
W/P. Keenan and G. Munch. Ast. J. 53 (1948) p. 194.
Baade, “The Resolution of M32, NGC 205, and the Central Region of the Andromeda Galaxy” APJ (1944) p. 137.
Sky and Telescope, April 1952.
Publ. Obs. Univ. Michigan 10 (1951) p. 33.
Ibid, p. 43 (w/ J. J. Nassau).
”Studies in Galactic Structure. I. A Preliminary Determination of the Space Distribution of the Blue Giants.” APJ 118, 318, 1953.
Large plot of plane of galaxy in Morgan’s office. Picture of this included in text.