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Interview of Albert Whitford by David DeVorkin on 1977 July 15, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/5147-1
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Interview centers around early life in Wisconsin; family background in Milton, Wisconsin; physics at Wisconsin and graduate work there; quantum mechanics under J.H. van Vleck and spectroscopy with Julius Ellis Mack and Mendenhall's influence; contact with astronomy and work for Joel Stebbins circa 1930; NRC Fellowship at Mount Wilson and contact with I.S. Bowen: work in spectro-scopy; influence of Trumpler and work on interstellar absorption; recollections of relations between East Coast and West Coast observatories; contact with Hale's associates; Shapley's regard for 200-inch and for existence of galaxies; continuation of work with Stebbins, at Wisconsin and Mount Wilson and continual choice between developmental work or production work in photoelectric photometry; John Hall's cesium oxide cells and a photoelectric guider; reception of electronics in astronomy pre and post war; growth of use of photomultipliers at Wisconsin: contact with V. Zworykin and use of tube in guider; collaboration with G. Kron; multicolor work with Stebbins; the "Stebbins-Whitford Effect" and its resolution with Code-Whitford spectrum scanner; research during World War II on radar at MIT; projects at MIT; post war changes in astronomy due to technology; Wisconsin after the war, Stebbins’ retirement; director at Washburn and micron survey of galactic bulge, 1945-1946; increased contacts at Lick Observatory; development of Wisconsin graduate program; origins of Kitt Peak and the Flagstaff Conference; move to Lick Observatory in 1958; conditions at Lick after Shanets and Sproults retirements; ApJ Editorial Board, 1947-1951; spiral structure of the galaxy, 1953.
I know you were born in Milton, Wisconsin, 1905. But I don't know too much else about your family, and I would like you to start with some comments on your family origins and your early life experiences, and include some brief biographical information on your parents and other close members of your family.
Yes. I come from an old Yankee family which traces back to an immigrant who came to Rhode Island in 1670. Both of my grandfathers were born in central New York State at a place called Leonardsville near Utica. My paternal grandfather, Albert, and his brother William came to southern Wisconsin in the early 1850's and had between them a major role in the founding of Milton Academy, which later became Milton College. My Grandfather Albert attended Union College, was educated in classical languages, but taught mathematics all his life. And when I was in high school. I had to read my Latin lessons to him, a subject which he still knew very well. My father grew up in the tradition, and after some time away at school in Chicago, was on the faculty of Milton College, teaching physics and mathematics. He later became president of the college, in the 1920s. It was a small private college. The community had a high percentage of New England Yankees. The tradition of quality, for a small and quite poor college, was amazingly high. From this background, I majored in physics in college. It was natural for me to consider graduate study. Many will recall that in the decade right after the First World War, the burgeoning graduate schools of universities were frequently populated by the graduates of high quality private colleges. I suppose I was a part of that era. I had no particular background in astronomy. My father taught the course, as had my grandfather as professor of mathematics. My father knew two or three astronomers at Yerkes Observatory, which was only 30 miles away. And I recall looking at Jupiter with a surveyor's transit telescope that my father had, and learning the names of the constellations. But when I went to the University of Wisconsin in Madison, it was physics. It was an era, often recalled fondly, of sealing wax and string, when every graduate student learned how to make his own apparatus. The leading figure in the department then was C.E. Mendenhall.
Let me ask you, your father had gone to the University of Wisconsin?
He studied at the University of Chicago, but later on, he took a year off and went to the University of Wisconsin and got a Master's degree. That was probably the source of the publication on which you came across. He told me when I was entering graduate school that his burning desire was to get married to his college sweetheart. My mother was my father's third cousin. Her maiden name was also Whitford. But this prevented him from going on to graduate school when he could have, at the University of Chicago.
Was it financial?
Well, I think so. He sat under Robert A. Millikan, as a matter of fact, in those years. He hoped that I wouldn't allow such considerations to keep me from finishing my graduate study. Well, perhaps we're going into more detail than you want?
No, I do appreciate the detail. I wanted to ask you more questions about your early home life. You were the son and grandson of members of the faculty at Milton College, so there was never any question but that you were going to go to Milton?
That is right.
But the choice of physics—was that as clear, from your father's interests? And from yours?
No. It was my own interest.
I'd like to know more about your earlier school years and some of the influences upon you, in high school, junior high school, if any come to light. Were there courses in physics? When did you first experience physics and math? Was it in high school?
I think it was in high school. I don't remember very much about my teachers. I was always going off on my own and reading extra books and staying after school to do private experiments which my teachers allowed me to do. I think a childhood chum, whom I lost track of in later years, was a little bit like Clarence Buddington Kelland's "Mark Tidd". He was an albino instead of a fat boy. He was always in projects, and got me interested in doing things with apparatus.
What was his name?
His name was Raymond Crosley.
When did you lose track of him?
Oh, I suppose in the 1940's or thereabouts.
What did he go into?
Oh, I don't think he ever went on into anything other than commercial connections and things like that. I do remember that I had four years of Latin in high school, and knew my teacher really well. Her name was Anna J. Plumb. And then I continued Latin in college, but I later felt that it was a mistake not to do more in modern languages.
I see. Did you later take any modern languages?
Yes, I learned German, actually from my aunt. Mrs. Anna S. Crandall.
The conditions of life in Wisconsin, as you were going through high school, during the First World War—were there economic difficulties for your family? Was there any question that you might have to stay and not go on beyond Milton College? Ever any question about that?
Well, as I have said, Milton College was a poor college, and the family devotion, and religious ties, never made my father anxious to go away and do something else. He accepted the low salary and rather modest living that came with it, without much question. I, like every kid around town, tried to get a job in the summer. I, worked on a farm, and earned self support when I went to graduate school. That was expected. My parents didn't help me very much beyond the first year, and I soon got TA's or something like that. Indeed, the universities had enough aids of this kind so that they were able to support practically all the graduate students they could take. That was of course long before the days of the NSF, and many of the students were supported out of state resources. Tax money, I suppose, for a good many of them.
What was your religious training? At Milton?
My family was Seventh Day Baptist, often confused with the Adventists, but they emphasized that they were quite separate. They were more related to Congregationalists, and did not emphasize or believe in the Second Coming as the Adventists do. But they did observe Saturday as the Sabbath, and that goes back to early times in the British Isles and perhaps on the Continent. Because it was so free and democratic a denomination, like the Congregationalists, it hasn't succeeded in retaining very many of its young people. It's not so very evangelical.
How strong was the church as you were growing up, in your family?
Well, we were all loyal and devoted, and it wasn’t until I went away from Milton that my own backsliding began. I was like the other young people, who usually did not remain loyal.
How did you bring up your children? It’s jumping ahead, but just to keep continuity on this topic.
No religious training at all. Some of them started to keep up with their schoolmates, voluntarily associating themselves with church groups.
Was this an active decision on your part, not to mention the religious affiliation? Or was it simply that our life got busier and busier?
Well, perhaps it was like the “Santa Claus myth” – we didn’t want to pretend things to our children that we didn’t believe ourselves. I remember my father worrying about it to me, and talking to my wife’s mother about it. He once said that he thought we were making a mistake, and that we were depriving the children of something they ought to have. He wished we would get them into some young group in some church, even the Unitarian!
So he was really concerned with association, and the fact that some religious identification would be made available to the children? It wasn’t anything stronger than that?
Yes. I think he remained active in church work. Although in his later years, he lived in a place where there wasn’t a Seventh [Day] Baptist church. So he went to another one.
Yes. “Even Unitarian…” [Laughter}
Three is a famous jibe, “The Unitarians say that there is at most one God.” But this religious connection maintained the purity of the New England Yankee inheritance. The migration went from New England to central New York state to Wisconsin. And there was a certain degree of inbreeding, of which I am a product. [Laughter] But nevertheless, there was, I would say, an excellent tradition of maintaining all that was best in the British and Colonial and New England heritage, in quite pure form, in this small town.
What was the specific area in Britain that your family came from?
I don’t know where my ancestor came from in Britain. Now since the publication of ROOTS, I am thinking about checking and trying to find out.
Was the name always Whitford?
Did you mention a town in New England?
Newport, Rhode Island.
OK. We can move on then, through high school to Milton, and I guess pretty much the influences at Milton were centered around your family still, or were there other strong influences upon you at Milton, in deciding your career?
Oh, I don't know that my career had thoroughly jelled, at the time that I went off to graduate school. I think I believed that I would probably become a teacher.
And go back to Milton?
Oh, it was not out of my mind. But of course one's horizons expand, as one meets a larger circle of acquaintances, and lots of new ideas. The tradition at Madison made it an exceedingly free place for the exchange of ideas. The famous bronze plaque on the front of the main hall, Bascom Hall bore the inscription: "Whatever may be the limitations that hinder and Trammel inquiry elsewhere, we hold that the great State University of Wisconsin ought ever to encourage that fearless sifting and winnowing by which alone the truth can be found."
Did you have any direct experience with laboratory research at Milton, before you left for Wisconsin?
Well, I did an undergraduate thesis in which I made some apparatus myself. It was an ultraviolet spectrograph. And I tried to do a little absorption spectrophotometry. There was strong biological interest in the college then, so I did test some biological materials. I didn't have any access to the current scientific journals that would help me very much. I think I borrowed some books that helped me through associations between-the college library and the University library in Madison.
Was the tie between Milton and Madison strong?
Yes. It was. There were always graduate students going every year. The then Dean of the Graduate School had a warm spot in his heart for the Milton people. His name was Charles S. Slichter. Charles Sumner Slichter, possibly the grandfather or great uncle of the astrophysicist now in Urbana, I'm not sure. His son Louis Slichter was professor of geophysics at UCLA. It's a famous family.
There was not much question but that you were going to go to the University of Wisconsin? Or did you consider other colleges?
There was an annual scholarship from each of the private colleges in Wisconsin for the magnificent sum of $250. I was awarded that and that tipped it. But I didn't apply anywhere else or think about going anywhere else.
Your father had gone to Chicago, you mentioned.
There was no passing interest in going there?
—Dr. Millikan had left, I guess?
Oh yes. He was already in Pasadena.
Do you think if Millikan had stayed there, you would have been interested in going to him particularly?
I don't know. I do recall that I was a little bit unhappy about some of the stodgy or quite classical interests of some of the professors at Madison. I could become acquainted with the University of Chicago because the Thanksgiving meeting of the Physical Society was always in Chicago, and various students went down. It was at that place I saw Michelson and Compton. Once when I was in Chicago for another reason I just dropped in to a lecture. It happened to be by Henry Gordon Gale. And he noted that the number of people and the roll call didn't jibe and asked, "Why was this"? I had to explain why I was there. Well, the lecture wasn't especially fascinating or modern, and I thought maybe I should go back to Madison.
Gale was an interesting name, associated with Hale and others. For quite some time.
Yes. Hale, Gale and Frost, remember?
Right, using the "Snow" telescopes.
However, my father's interest in Chicago wasn't just his own study there. Now, you're getting me far, far afield, but his sister, my aunt, Anna Crandall, from whom I learned German, married Eugene Crandall, who was a divinity student at Yale at the time that William S. Harper was dean of the Divinity School in New Haven. And Harper brought my uncle to Chicago, to run a kind of a correspondence school, with the objective of improving the knowledge of Hebrew among small town preachers. My uncle got a PhD in Hebrew languages. His health broke down and he had to resign. He moved to Milton, and my aunt became the teaching member of the family. During his studies, they spent a year in Berlin, as everybody did in those days if he wanted to be really educated.
Yes, in Berlin, in Germany. And that was where my aunt learned German.
What was that year approximately?
OK. I'm thinking of Chicago—as you mentioned, certainly Michelson was there, and there were other people very well known at that time for instrumentation, laboratory work—I'm interested in how you got more and more involved in instrumentation. I'm very interested in this ultraviolet spectrograph when you were an undergraduate. Do you recall who suggested that to you? Or is that something that came out of your own interests, to work on this project in Milton?
I think I thought it up myself. I don't think anybody suggested it to me.
Do you recall making gadgets when you were a child at home?
I was always interested in it, but I always felt that everybody else's father was enough richer to provide better tools than we had, so I can't remember that I made a lot of gadgets. No. I think I was always interested in tinkering with bicycles, and Mechano type devices, motors, batteries and lights. I had some dream of making a switchboard, but it never got very far.
Well, I can't remember all that it was supposed to do. It was to run motors and lights and things.
So you could just have a series of knobs of toggle switches, where you could direct different—?
Yes, but it was knife blade switches in those days. Toggles hadn't been invented yet.
Right So it was double pole, double throw?
Yes, or single pole. Or double pole, single throw, and so on.
When you were going to University of Wisconsin as a graduate student, did you have anyone particular person in mind that you wanted to work with, or one particular direction that you wanted to take?
It was in a period when physics was changing rather rapidly. Quantum mechanics, which is now a senior undergraduate subject, was considered the most difficult subject for especially these, "do-it-yourself apparatus-maker type students". I learned it under J.H. Van Vleck, who is still at Harvard. Must have reached retirement age now. He was a rather young professor at the time.
He was at Wisconsin.
Was this your first experience with quantum physics?
Yes. His father had been a famous mathematics professor on the campus.
You asked me how I got interested in physics. It was at a time when atomic spectroscopy was developing. Russell Saunders coupling and the J-J coupling were the words. I studied up on it a good deal through a book by Friedrich Hund in German, called LINIENSPEKTREN, on my own.
This was not taught as part of the quantum course?
There wasn't any modern spectroscopist on the campus then, although Julian Ellis Mack came before I finished my physics training, and he was actually my major professor. And I did a spectroscopic thesis. But it didn't lead to anything more. I did pursue it some, when I got the NRC. Fellowship which was nominally in physics, jointly between Cal Tech and Mt. Wilson. A minor publication came out of it It was during a time when I was being weaned over to astronomy. That's probably the thing that you would like to know more about.
I wanted to be sure that we would give proper credit to Julian Mack or to others. I'd be interested to know how you were directed to your graduate thesis, and the structure of the course offerings, what the quality was of laboratory equipment at that time, at Wisconsin, that sort of background.
Well, you're dusting off some cobwebby back rooms in my memory.
If you don't mind?
I think that it may have been C.E. Mendenhall who directed my attention to vacuum spectroscopy in the extreme ultraviolet. This had been quite an important development in laboratory physics at the time. Two of the leading practitioners were Millikan and Bowen. Harvey White at Cornell was another. During his years at Berkeley, he was a co-author of Jenkins and Whites Optics, and later had a leading part in establishing the Lawrence Hall of Science. I did my reading with Millikan and Bowen, and had Mendenhall's help in getting shop facilities. There had been another graduate student who had worked in the field whose experience helped.
If I could just ask you a directed question about Bowen, you had no contact, I'm assuming, with the Cal Tech people?
But you had contact with the literature?
Had you learned of Bowen's work in fluorescence mechanism at the time, '27, '28, '29?
I don't think so. I knew about forbidden lines. And I can't remember when I first read about the fluorescence mechanism. I built a new vacuum spectrograph, and became interested in isoelectronic sequences. I had hoped that, by extrapolating back from the argon I sequence, AI, KII, CAIII, etc.-I could get a binding energy for the -negative chlorine ion, which has a stable configuration. And I worked on it a while. But I didn't succeed.
Who did you discuss your instrumentation needs with? And who helped you in the designs? Or were these all designs that you had developed, the vacuum valve couplings and that sort of thing? Was it Mendenhall?
He was over it all, with a pretty good instrument shop. There was a German-born instrument maker, and he could pretty much make up things as you went along, if you gave him a few dimensions and some sketches. Vacuum technique was something that every graduate student automatically absorbed by osmosis. We used mercury diffusion pumps and liquid air. Getting a vacuum and finding leaks was just part of the trade. It was long before helium leak sniffers. Some of our techniques, by modern standards, weren't awfully good, but they were good enough. I got good vacuum ultraviolet spectra going down to about 250-300 angstroms. It seems to me that the scandium sequence that I hoped to find, I never could find. Anyway, I can't remember the motivation of doing the Zeeman effect thesis that I did—if I went back and read the paper, it would come back to me.
You indicated that your NRC work was an extension of this, to a certain degree. We can come to that eventually. But during the years between perhaps up to 1932 when you received your doctorate at Wisconsin, did you have any contact at all with the astronomy department.
Yes. That's how I got into astronomy. During the latter years of my graduate study, I got a bit restive, and as a way to bring in a little more money to make me happy, Dr. Mendenhall recommended me for a research assistantship at the observatory. Joel Stebbins had such a position, which had been held by physics graduate students before me. It was there that I got my first introduction to astronomy, and the weaning over began.
What were your duties?
Well, I might give you a preprint or a Xerox of the manuscript of Joel Stebbins biographical memoir. That would give you a background on it. Stebbins had quite successfully made an astronomical career out of measuring, first the light curves of eclipsing variables, and then the colors of stars by photoelectric methods. He was the only one in the U.S. that was doing it, for a long time. And the results with the rather modest telescope on the Wisconsin campus—15 1/2 inches had been quite rewarding. He had been helped by occasional visits to an observatories with larger telescopes. But he was always trying even before he left Urbana in 1922, to get something better in order to be able to measure fainter stars. He recalled the first time he tried, he couldn't even detect Jupiter with a 12-inch telescope.
His first cell was the Selenium cell?
He used potassium cells after that?
Yes. The selenium was a photoconducting cell, and the potassium was an emission-type cell. It wasn't a vacuum photoelectric cell. He put gas in, and used ionization in the gas to amplify the photocurrent. The voltage was kept below the glow point, and the extra ionization multiplied the original photo-emission by, oh, five to ten times.
It still had external amplification, though?
No, the measurements were – in the days when selenium was used – with a d’Arsonval galvanometer, and a bridge circuit.
Which kind of galvanometer?
D’Arsonval. That’s just a moving – coil galvanometer. You don’t remember all that? But as soon as one was working with direct photemissivecells, the currents became very much smaller, and he had to use electrometer methods; the Wulf-string electrometer was used first, and then later a thing called the Lindemann electrometer.
The Lindemann I'm familiar with, but this is Wulf-string?
The Wulf-string electrometer had two quartz fibers that repelled each other when charged up. Then as you put the current in it and discharges it, and the fibers moved at a rate observed with a microscope.
And you viewed that directly under a microscope.
Yes. The Lindemann was a quadrant electrometer, with taut quartz fibers, coated with gold to make them conducting. It would work in any position, which was good for working at the end of a moving telescope. That Lindemann later became Lord Cherwe1l, who was Churchill's confidant.
When you first became a research assistant, which photometer was in use?
It was the Lindemann.
What were your duties?
Well, for some years there had been a project to try to measure smaller currents by amplification. The difficulty was that ordinary vacuum tubes had internal defects that made the noise level much too large to do that. And it was at just about that time, around 1930, that there had been an important development, by Metcalf and Thompson at General Electric. They devised a special vacuum tube in which all the resources of grid current were made extremely small. I can give you a reference to an historical review of this development, if you would like?
A chapter I contributed to HANDBUCH DER PHYSIK.
OK, we can locate that.
And so I came into it with this vacuum tube existing, and being tried out in various physics laboratories. But nobody could ever quite get the claimed noise level, the level one should get, given the parameters of the tube.
Were you made aware of the problem by the people who brought you in, Stebbins? Or was it something you were aware of from the general literature?
Well, the standard way to measure small currents, when I entered physics, was the Compton electrometer. But it wasn't applicable in astronomy, except in Coude’ situations. There was one astronomer in Pasadena named Sinclair Smith who used that kind of electrometer—actually a better one made in Germany called the Hoffmann duant electrometer. He worked at the Coude’ focus.
Smith was —was that contemporary? More or less contemporary, although I didn't know about it. a physicist trained at Cal Tech.
What I'm interested in getting at is, was Stebbins aware of these developments in physics, to the degree that he said, "Find a way to use these new vacuum tubes by Metcalf"—or was it something you looked for on your own.
Well, it was general knowledge in the physics community. L.A. DuBridge spent a summer at Schenectady trying the tube out, but the fine results he obtained couldn't exactly be duplicated in trials within the Wisconsin Physics Department. It became understandable later, why. And this was general knowledge, among the physics group. I think Stebbins didn't have this knowledge. But he knew the ins and outs of electrometers quite well-such as the need to have all insulating surfaces very clean and dry, to use electrical guard rugs, and to keep the air around the electrometer free of moisture by use of drying agents. Without these precautions the damp air in the dome was sure to cause trouble from leaking insulators. He always used amber for the insulators. He had a stick of it that came from somewhere in Europe I think. Amber was used in physics laboratories, too. It was in all the old recipe books, that amber is really a good insulator.
So what was the working relationship between you and Stebbins?
Well, I was given carte blanche to do what I needed to do to get results. As it finally turned out an important hint came from some experiments that one of the physics professors in the department had done. He found that when he kept the sensitive lead, as we called it, encased in a metal tube filled with ceresin wax, the noise went down. Then the idea came to several of us, I don't quite remember who, that it was indeed ions generated by cosmic rays that were causing the trouble, and that there was a high enough voltage around a photoelectric cell to pull them in from quite a volume. If you pumped out the air, there wouldn't be any cosmic ray ions, and the noise should go down to its theoretical limits. That was the step forward that I managed to get working. So I built a photometer which was put first on the Washburn telescope. I immediately brought fainter stars into the realm of observation. It was at about the time that Stebbins became a research associate of the Carnegie Institution, and thus had regular time on the Mt. Wilson telescopes. He was very interested in getting this amplifier device to Mt. Wilson, Pasadena, and in my getting an NRC fellowship that would allow me to work in—I wasn't sure till I'd gone to Pasadena and had worked there in both physics and astronomy', that astronomy was what I really wanted to do. Stebbins never pushed. He never pushed. He just seduced. (Laughter)
What were your first impressions of him as a man? How did your personal relationship with him develop?
Well, it became a very warm and almost affectionate relationship over the years. But he had a slight aura of austerity, when I first met him. Extremely friendly, helpful, patient, forgiving. In some remarks I made at his farewell dinner, in 1948, I recalled the first time I went to the observatory to talk to him about the job. It's an old observatory, older than Lick Observatory, built in 1878, out of Madison sandstone, on a gorgeous hill above the lake.
What kind of sandstone?
Madison sandstone, which was used for many of the old buildings around the university. High Victorian ceilings, bearded portraits around the walls, certain carved book cases, which were actually copied on' Mount Hamilton by E.S. Holden, when he went from Washburn to become the first director of Lick. These carved book cases in the first Lick Library were still there until sometime in the 1950's—they came when the old library room was remodeled into an assemblyroom.
Yes. My early recollections at Washburn Observatory also included ticking clocks, which took one way back – the sidereal clock was in a special double cabinet. There was a Meridian Circle, which hadn’t been used for a decade or two.
By that time, they'd ceased using Meridian Circles?
Yes. Yes, that's right. Professor A. S. Flint, whom I never saw was the last one to use it. But in the basement, there was a workshop, which Stebbins found money to buy tools for.
Where do you think he got this money? Where did his sources come from?
Some of it came out of the support that the University of Wisconsin gave the University. He got some private grants, from places like the American Philosophical Society, and various other sources. I don't have verification, but I think during this process, he got a little money from Hale to develop instruments for the 200-inch telescope.
For the 200?
Yes. It was in 1928 that the Rockefeller grant to build the 200-inch came through. By 1931 or 1932 the project was still in the design phase, and putting money in related developments could be justified. Hale believed very strongly, as you know, in making the auxiliary instruments as modern as they could be. I don't know exactly where support for Stebbins development work all came from. I don't remember. I don't have the documentation.
OK. Sure. But it is an interesting point, especially if Hale had supported him—he certainly was aware of the development of photoelectric work.
And your mention of the simultaneous use at the Coude'-this was by Sinclair Smith—I think should be followed up. I may follow that up at Hale Observatories and see what he was doing.
If it never got into a published article, you could certainly find it in the annual reports.
Yes. Exactly. Did you take any courses in astronomy during this time?
No. One of the things that came from the kind of physics training I had was the knowledge gathered from rather independent reading. I learned more physics that way than from I was taught in formal courses-a great deal of modern physics had to be picked up by osmosis. Of course, there were colloquia, and visiting professors form England, or more likely Germany—I remember a short visit from Heisenberg, a longer visit from Gregor Wentzel—
Did you have any personal contact with these people? Whitford; Well, I think I went to some lectures by Wentzel. Peter Debye was another one. To finish answering your question. One of the good things about that way of learning and indeed I think it may be the best way even now—was that I was forced to wrap myself around a new subject using my own resources, rather than being carefully guided into it and tutored. And I found I could do it on my own, more than once. And so, when astronomy became larger and larger on the horizon. I picked up a fairly good background in the subject through spin-off and conversations with Stebbins, and by my own studies. I never had any formal course in it.
Stebbins and Huffer I believe did teach courses in it. In astronomy there, at the time. You had no contact at that time?
No, not as a student. Later on, when I became a faculty member, I taught some of these courses myself and got the automatic benefit that came from being required to dig into the fundamentals of the subject. These were elementary courses. Stebbins resisted establishing a graduate program. Near the end of his years as an active faculty member, Olin Eggens persistence and determination won out over their attitude. Eggins became the second PhD in astronomy at Wisconsin. Huffer was the first.
Let's see—in astronomy directly, Eggen was the second, Huffer was the first? There's quite a long period of time between the two.
Yes, about 20 years. Stebbins felt that graduate students should be discouraged rather than encouraged because there weren't enough jobs. He also felt there weren't enough resources in the Wisconsin department to do as well as ought to be done—and that the most promising students should go to the larger centers. It's interesting that in his own career, his first graduate study was at Wisconsin also.
Under Comstock, George Cary Comstock, who succeeded Holden as director. When Stebbins came from Lincoln, University of Nebraska, in 1900, Comstock gave him a very good introduction to astronomy. And Comstock must I think be viewed as somebody who was quite aware of the rise of astrophysics in astronomy, although pretty much a classical astronomer himself. After a year here in Madison when Stebbins apparently impressed him, he said, "You ought to go on to a place where you can get better training in the new astronomy, which means astrophysics". Stebbins considered Yerkes Observatory, but when a Lick Fellowship was offered to him, he jumped at it.
Stebbins went to Lick at that point.
Yes. He got his degree at the University of California, Berkeley. It was all there was of the University of California at the time.
Yes. He then really felt that someone should go elsewhere than Madison for his graduate astronomy training.
Yes. When he came to Wisconsin as director, he had an agreement with the then president, and the dean. They wanted to have an astronomy department, and they would support research by the working staff, and agreed to light teaching. It was just sort of a genteel thing to in those days. I remember that the dean under whom I served, Mark Ingraham, (and this rather spoiled me) said that he believed that University of Wisconsin had always, since the Van Hise presidency wanted to be counted as a major league university, and it had been. Maybe I'm interpolating a little bit, but I will now quote Ingraham - "a first rate university simply has to have somebody who knows about two things, and can teach students about them if they want to know. Those two things are the classical languages and astronomy, and they must be maintained, even if there are very few students."
Nice attitude for astronomy. Just to go way ahead at this time, this is just an anecdote, but I visited Washburn a number of years ago, wasn't it occupied at that time on the first floor by the classics department?
Yes. After I left my successor - Arthur Code - jumped at the chance to get some modern quarters and some roof-top installations on the top of the physics building. There have since been fenced in by high rises all around. The telescope in the old house on Observatory Hill was maintained for visitors, but at the same time a country station was set up. Getting that built was more or less my valedictory there.
That was your valedictory?
Yes, getting that country station at Pine Bluff established. Yes. And of course, Madison had made the sky around Observatory Hill much too bright, and the telescope was outdated. These developments left the way open for this very, very classical Victorian observatory building to be occupied by an Institute for the Humanities. I haven't been inside the place since I left.
Very interesting association, about Ingraham wanting to associate astronomy and classics, in that way.
I don't know how the decision to use the old observatory building in that way was made.
Well, let’s go back to 1932 and your growing interest in astronomy. How did the fellowship at Mt. Wilson develop? Was this directly through Stebbins?
I had expressed interest in a National Research Council Fellowship. This was the postdoctoral fellowship that physics students could aspire to for further domestic study at that time. I had in fact applied for it on my own the previous year. But Stebbins encouraged me to re-apply, with the tie-in between spectroscopy under Bowen and astronomy at Mt. Wilson under him, essentially.
That's right, he'd been going to Mt. Wilson periodically.
Yes, and he wanted to enlarge the range of objects that he could observe even with the extra light gathering power of the telescopes. And they were quite generous within giving him time on the telescopes. So that started a long association. In those two years, I spent more and more time doing astronomy, working on the mountain, and less and less doing physics. And I saw that astronomy was what I was not interested in. Stebbins didn't make it hard for me, but neither did he force it. And when I finished the fellowship, he got me a one-year research appointment in Madison. I was appointed to the faculty for a year later.
Had you considered other possibilities? The possibility of going to Lick, as others from Wisconsin had done? At that time?
There wasn't an opportunity. Jobs in the thirties were pretty scarce. The average number of astronomy Phd's in the whole country in those days was about eight, and they didn't all get jobs.
How about your family? They remained in Milton during this time. Was there any hardship?
No. My father resigned as president of the college, and spent the last years of his life with Alfred University, in Alfred, N.Y., as dean of the college.
Was the reason he resigned having to do with long tenure?
Well, there were problems, and I think he felt that he was not coping with them. There are always problems in small private colleges.
How did you feel about this? When was this move, for him?
Oh, 1930 odd.
You were in the middle of your Wisconsin studies.
I was still in Madison.
Did you consider yourself pretty much independent of your parents by that time?
Well, not disloyal. But I was self-reliant.
So you didn't see this as any great change that would mean that you would have to move, too. There weren't any feelings pulling one way or the other. You felt the most important thing for you was to continue through at Madison?
As you moved on to Mt. Wilson, at the time, do you recall becoming interested in any particular problems of study, with the techniques that you were developing and using with Stebbins? Stebbins and Huffer were doing variable star work at that time, and Stebbins was getting interested in red stars, and then very bright stars, and 0 and B, I guess, were the stars he was studying.
Yes. There were two main areas of research, and you can read this in the biographical memoir. One was the demonstration of the extent and mapping of the interstellar reddening by the colors of test objects. OB stars were excellent test objects because they're so luminous and have such clean spectra, not mucked up with a lot of absorption lines and blanketing. Although blanketing hadn't become a household word at that time. DeVorkin : That's right.
The other test objects were the globular clusters, because they were known to be at great distances in the galaxy. I think the differentiation among the globular clusters wasn't then known, but the reddening of some of them was so pronounced that it was astounding, and it had never been detected photographically. I helped in both of these and became interested in both problems. And later research that I did myself in establishing the law reddening all stemmed from that. It was quite clear, with a twocolor index, you couldn't draw the curve for the whole range of wavelengths. You just knew two points on the curve. It might go this way or that way.
A positive curve, a negative curve—
Or straight, a straight line, depending on what coordinates you plotted it with. Well, the first analogy was with Rayleigh scattering in the atmosphere, it could be a law. De Vorkin: What about Trumpler's work?
Well, that was what motivated the study. From a visit to Lick Observatory, Stebbins became acquainted with Trumpler's results. That came out about 1930, but the data had existed before that. The proof of the existence of general absorption in the Milky Way was based upon apparent diameters of open clusters, as you must recall. It was a pretty statistical result, since you have to take the open clusters where you find them. Of course, Trumpler's pioneer study of open clusters was one of the landmarks in the research done at Lick Observatory, in my estimation.
But what was needed was something more like standard candles and more precise models, more precise mapping. There finally got to be 1300 B stars whose colors and been measured by Stebbins and Huffer, and by Stebbins Huffer, and Whitford.
Well, the evidence became overwhelming and quantitative, and the evidence also became overwhelming that it was spotty, and that no one coefficient of absorption in magnitudes per kiloparsec, would do. Likewise probably no cosecant variation with latitude would do, except as a kind of a statistical result, which one could fall back on if he didn't have anything else to go on. The second result was that, with so much reddening in front of the globular clusters, their apparent faintness wasn't a result of being very far away, but because we didn't see all the light. And so the revision of the scale of the galaxy, which was in progress at that time as a result of studies of the rotation of the galaxy, that was substantiated this way.
Let me ask you a few general personal questions about your coming into the field at this time, and your association with Stebbins. Did Stebbins ever recall his trip to Lick Observatory, to talk to Trumpler, or that particular meeting, and how he became aware of Trumpler's work? I know that Stebbins was understandably a pretty good story teller.
He certainly was a good story teller, but I don't recall his recounting his conversations with Trumpler. I blame myself for this, that in his post-retirement years, and he kept active until he was 80 years old, no one gave him an opportunity to record an oral history of his early days in astronomy. He remembered a great deal about the personal characteristics of leading figures of that time, of the astronomers who founded what became American astronomy. He carried these recollections to his grave. I recall many of the stories that I heard him tell more than once, and many of the quips and anecdotes were so delightful. But it would have been nice to have had it on tape. And I could have done something about that, I suppose, but it wasn't the thing, it wasn't de rigueur, in those days.
Well, tape recorders weren't as easy to handle at that time, and it wasn't in everybody's mind to use tape recorders for that purpose. It's a relatively recent phenomenon. I think.
Well, in further answer to your question about Trumpler- I do recall that in his first publications on interstellar reddening, Stebbins did acknowledge that his was where the idea came from.
Did he ever talk to you about the significance of the discovery, not only the discovery of reddening, but its use in shrinking the size of the galaxy. Was there any correspondence or any interaction with Shapley, and with his reticence to believe in absorption at that time?
Well, I referred to this in a piece I did for the New York Academy which you may have stumbled on.
No, I haven't seen that.
Well, I'll give it to you.
OK, let me read this for the tape. This is: "Personal Accounting of the Development of Modern Astronomy, Astronomy and Astronomers at the Mountain Observatories", from the New York Academy of Sciences—is this by any chance the conference on history of astronomy?
Yes. Berendzen's meeting.
I thank you for the copy and I'll certainly put it in the file.
The reason I referred to that is that in the latter part of this little account—it's not all anecdotal, some of it is just from the literature—I refer to the fact that as soon as I came to Mt. Wilson, I was made aware of the running feud between the East Coast and the West Coast astronomers. Shapley was the personification of the East Coast, and at the other end it was all of the West. It had begun years and years before at Lick Observatory.
Between Lick and - ?
Well, I can remember an anecdote of Stebbins from his graduate student days. They had a visitor from the East who was something of a dude, a dandy. He was arrogant. I never found out the man's name. You could read about it in the letters he wrote to his family during those years, which I asked Mrs. Shane to put in the archives.
Mrs. Shane does have the Stebbins material?
It's a fine picture of life on Mt. Hamilton from 1901 to 1903.
I got the letters from his family, in the preparation of his memoir. They organized a snipe hunt, for the special benefit of this Eastern visitor, and it worked beautifully.
I went on a snipe hunt once when I was a Boy Scout. It's a Western phenomenon. No one's heard about them in the East.
Yes. By the time I got to Mt. Wilson, Shapley was not much admired around Santa Barbara St. Hubble never lost an opportunity to speak rather regretfully, about the fact that a young man who had started out so brilliantly, during his Mt. Wilson years, had since taken to leaping so far and so fast on rather poor observations.
Was that the essence of the difference, then?
No, what I remarked about in that paper is this: Both Mt. Wilson and Lick never allowed themselves to forget that they were the first mountain observatories, that they had wonderful telescopes, wonderful skies, and the best instruments and the best observations, and that a new standard of accuracy and precision had thereby been established. And they felt they were the carriers of the tradition. As observers who had lived and grown up with the telescopes, they approached their assigned nights on the telescopes with devotion, almost with reverence. They felt that astronomers in the East were forced to compromise with poor sites, poor telescopes, poor adjustments, not as refined technique, and were inclined to speculate on the basis of inconclusive data. This was reciprocated: the Easterners felt that the mountain dwellers had become hermits who were so obsessed by the idea that no clear night hour should go unused that they didn't really know as mush as they should about a lot of developments in theoretical astrophysics.
This was Shapley's argument?
Well, Menzel, and others, but Menzel was the leading proponent of it. He tells something about it in this same series, Berendzen's conference.
There was a certain amount of truth in both points of view. And it's long since been erased.
In the case of Shapley, what we're looking at now of course is a very direct topic, the dissension between Shapley and Hubble, and of course, the further discovery of interstellar reddening complicated the issue. Did you ever have any direct experience of this, in talking to Hubble, or talking to Hale, if you met him?
I met Hale, during my fellowship year in Pasadena. He was still trying to detect the general magnetic field of the sun, and was drawing in various people around the observatory, and Cal Tech. John Strong was then working in a Cal Tech laboratory devoted to 200-inch projects perfecting the technique for aluminizing mirrors. He was spending some time on the solar magnetic field. He was probably the one who suggested that I could help out by making some direct photoelectric measurement of the two components of polarization. At any rate I was asked to come down to Hale’s Solar Laboratory in San Marino. De Vorkin: Hale's home?
I think it was adjacent to the home of one of his family. It was his private laboratory. I believe he built it with his own hands. I worked there for two or three weeks, with my photocell and amplifier, but we never got a positive result. I don't know whether it was due to the fluctuations in my own apparatus, or to the doubtful atmospheric variability. It had to be "to and fro" measurement, and those are always dangerous. We could not flicker back and forth in a fraction of a second. That's the way it is done nowadays. Horace Babcock finally developed the technique and was able to go more than an order of magnitude beyond anything we could do. The general magnetic field that he finally measured was much smaller than the field that Hale thought had earlier been detected on the spectrograms.
Was Hale engaged directly in the research with you?
He planned and guided the work, but the actual operations were carried out by helpers and co-workers. He had an instrument maker that he employed, who opened and closed the observatory. Sometimes Hale stepped in and made an adjustment. During an observing run he often stood by and watched. On occasion he talked quite animatedly—very fascinating stories about what he was interested in, and about some of his previous years. His study and library upstairs was just a magnificent place. He had all kinds of interests —one was Egyptology. He was a great friend of James H. Breasted at Chicago. Several objects that had come from Egypt were displayed in the library. I treasure the recollection of having seen him, in his retirement years. This was 1933 or thereabouts. He mentioned “the cobwebs in his head” —a reference to his recurring psychological difficulty. He had had more than one nervous breakdown, and his health finally forced him to resign as director of the Mount Wilson Observatory in about 1923. He wanted to keep doing science himself, using his time as a way of sweeping away those cobwebs. Most remarkable. And I recall my aunt recalling that she remembered Hale on the Chicago campus. They rode bicycles together along the Midway.
You mentioned that your father had had contact with the people at Yerkes, and I was going to ask if he had contact with Hale.
No, it was long after Hale had left. People like Barrett and maybe Edwin Frost, who was director at the time.
I wanted to ask you if you had any contact with some of Hale's laboratory associates, such as A.S. King or any others?
Yes. It was an interesting time to be in Pasadena when I first went there. Of course, a good many of Hale's original staff were still around, and A.S. King was one of them. There was a laboratory on Santa Barbara St. where he did his spectroscopy, and where Sinclair Smith did some of his experiments. And I worked in a corner of it some of the time. Others were H.D. Babcock. Also W.S. Adams, A.N. Joy, Ferdinand Ellerman, who was a photographer. Even Charles St. John, although he had just about retired when I got there. Then A. Van Maanen and Francis Pease, who had dreams about a 300-inch telescope and who built that 50-foot interferometer that never worked. And of course, E. Bettit, Seth S. Nicholson and Paul Merrill who were later additions. And Edwin Hubble and Walter Baade.
Yes, a lot of people. The people that you were directly associated with were naturally more involved in laboratory work and spectroscopy—Char1otte Moore might have been around at that time?
She was a visitor. Of course, Stebbins' position as a research associate was parallel to that of Henry Norris Russell, and he was there for part of the year. A legendary figure.
How did your research develop, your own personal research, in addition to what you were doing in Hale's lab?
Well, it was all joint with Stebbins for a time. But the next subject in his research career was one that was being taken up at that time, and that was the photometry of galaxies, then called nebulae because Hubble preferred the term.
Did he ever talk to you about why he preferred that term? Why he always used the term "red shift" instead of "velocity recession"?
He mentioned his preference in The Realm of the Nebu1ae, but I'd have to look it up.
Nothing direct that you recall.
No, I don't remember Hubble saying anything about it in my nearing. I would want to look up the exact words in the Realm of the Nebulae. If I find it, I'll show it to you. One was that he loved tradition, especially British tradition, from his Rhodes Scholar days. And so, a Word whose usage had been hallowed by a hundred years or more of usage wasn't easily changed. And of course, he did as much as anybody to make it clear that there were nebulae and nebulae-unresolved clouds of nearby gas and dust, and distant stellar systems. He was the man who provided the evidence. The word "extragalactic," as you know, just meant, in angular coordinates, outside the Milky Way belt. It didn't mean beyond the Milky Way as a galaxy, originally. Nevertheless, "extragalactic nebulae" got to be the words he liked to use. I think Shapley was probably the leader of the campaign to try to make "galaxy" with a small "g" the word that applied to these external star systems. And indeed, it's universally adopted now, because it's a word that is descriptive and useful. I don't know, but it's just possible that the fact that Shapley tried to change the usage and popularize it induced some reluctance on Hubble's part to take it up himself.
In your year or so at Mt. Wilson, at Santa Barbara St., when you knew you were going, how did you personally feel about this chance to associate with the astronomical staff that had done so much to revolutionize galactic astronomy and extragalactic research?
Well, I guess I reveled in the prospect, and it was a very exciting experience. I'd never been to the West Coast before. Stebbins paved the way for me, and I had lots and lots of help. Stebbins had to go back to Madison during the academic year to carry on his faculty duties, although I believe he got one spring term off, during those two years. And during these times, when I wanted to do something astronomical, I certainly got a lot of help, in the observatory and the shops, Walter Adams, who was the director, saw to that.
Who were you closest to there, in terms of your research interests?
Oh yes. I mean, on the staff.
Well, I think that the people who had the biggest influence on me were certainly Hubble and Baade. Among the younger people there, there was a graduate student at Cal Tech, with whom I was very friendly. His name was Olin Wilson, and he was Cal Tech's first graduate student in astronomy. He went into spectroscopy, learned his trade under Merrill. He has recently retired from the Mt. Wilson-Palomar staff.
Merrill was still very much around?
Yes, he was still very much around, and was quite a vigorous character.
I'm thinking in terms of the fact that you did extend your laboratory spectroscopy work. — whom might you have worked with? Did you ever actually work with King directly?
No. I was doing vacuum spectroscopy and was doing it in Bowen's lab, at Cal Tech. De Vorkin: So you were working in Bowen's lab. Did you have direct contact with I. Bowen, then?
Yes. I saw him frequently.
But it was no longer a situation where someone was supervising your research, you were on your own?
What about the continuance of photoelectric study? Who was interested in this sort of new technique at Mt. Wilson, and did you continue it during that time?
Well, the first project that I did on my own, — let's see. Stebbins was induced by Hubble and Baade, to go into the photometry of galaxies, a subject we got started on when we started talking about the difference between nebulae and galaxies; photographic techniques for measuring these subjects were not very direct. A Swedish astronomer working at Mt. Wilson named Eric Holmberg finally did refine the technique and make it quite exact.
The photographic technique?
Yes. By strip scans and integration, using the characteristic curve of the photographic plate. But the photoelectric cell could take all the light coming through a diaphragm that was large enough to encompass the galaxy, could thereby measure the integrated magnitude irrespective of the distribution of light within it. Offset measures on a nearby piece of the sky were used for subtracting the foreground light. Photoelectric magnitudes of galaxies offered an immediate advantage, and everybody saw it. It was all a part of Hubble's attempts to refine the cosmological work — you had to have accurate photometry. So he induced Stebbins and me to recalibrate their stellar sequences. This involved the so-called North Polar Sequence, and the selected areas. When we finally finished the selected areas and found out there had been quite big errors.
Did Stebbins at this time, or did you feel torn between developmental research and doing production work with photoelectric cells?
Yes, this has been a continuing tug in my life and the lives of others, as to the philosophy of what a staff member in an observatory should be. It's continued into modern times here. I think I got ahead because I somehow managed to make the apparatus work, and make it work in a way that kept advancing what could be done. But as soon as it was clear to me that I was going to try to make a career out of astronomy, I think I said that the end was more important than the means, and that I wanted to be doing astronomy that seemed important, rather than just making the apparatus or doing measurements for somebody else to say, "This is great, and this is what it means".
Yet you certainly did both, throughout your career.
Yes. And so, while I felt that the next step in instrumental development had to be taken, had to be kept going, I also wanted to use it to do something significant. I don't think that hope was fully realized — that was the ambition, not necessarily the realization.
Well, during the thirties, then, after you had successfully produced this vacuum amplifier, and I guess that was still back in Wisconsin, you pretty much used that design well through the decade?
Yes. We changed the shape of the hardware, but the same principle was used, up to the time that we all went off and did different things during the war. However, some of the very first multiplier devices were coming out in the late thirties, and we had samples of them.
We'll get to that soon. Why don't we be sure that we've covered, at least to a reasonable level, your experiences in Pasadena.
Yes. I don't think I quite finished what I started to say. The first research that I did on my own was the photometry of bright galaxies. It was done with the 10-inch telescope on Mt. Wilson, a four-lens refractor, but it had an F-ratio much like the refractors. Of course, it had a small scale, so it was good for getting the light of the large, bright galaxies through the diaphragms.
Were you doing color work at that time on galaxies, in addition to integrated brightness?
On that particular project, it was only integrated brightness. But it soon became clear, as I started to say previously, that the two colors — well, the two bands, only one color, since color is the difference between two magnitudes at different wavelengths couldn't tell you very much about what you ought to do towards correcting the apparent brightness to the intrinsic brightness. To interpret what would be observed with the reddening removed, you had to have the whole curve. In the late thirties, there was another development, that helped. John Hall, at Yale, was the pioneer in putting into use a new photocell with a very wide spectra range. That kind of a phototube had to be refrigerated, because it had so much dark current at room temperature.
— John Hall was at Yale at that time?
This is the lead sulfide cell?
No, it was the cesium oxide photocell. It became the standard photo-cell for sound movies, for a long time.
That's interesting — you mean off the side of the track, the sound track?
Yes. It had high response in the red and near infra-red. And since one wanted to use incandescent lights; you couldn't have very blue sources. It was enormously better than anything that was available before, and at those high intensities the high dark current didn't matter. And it was solid commercially; you could go down to the local store and buy a dozen or a hundred. But these commercial cells were not built to handle very low light levels and very small currents. They had a complex cathode with a very low work function, low enough to make the red photons able to release electrons. They were sensitive out beyond 10,000 angstroms. But the low work functions permitted some spontaneous emission even at room temperature, from just general thermionic emission. This had to be reduced by refrigeration with dry ice. John Hall showed how you could do this. We hooked up the photocell to the amplifier, and then made our first attempt to try to map the reddening curve. This was done at Mt. Wilson, with a spectrophometer of the slitless type. We saw that the result they'd gotten at Yerkes was correct, that it wasn't -4, but was closer to -1. That was right, but it was an extremely difficult instrument to use, because in a slitless instrument the wave length at the exit aperture depended on the guiding.
Yes, I see. What year was this?
1937, '38. It's reported in one of the papers by Stebbins, and Huffer and Whitford.
Right, OK. At this time, during that year, you and Gerry Kron worked on an automatic device for guiding telescopes. Was this just a parallel activity, or was this something that helped with the spectrophotometer?
No, it was just a device that people had thought it would be nice to have.
Who did say that?
Oh, just gossip around observatories. It was one of those Buck Rogers ideas. Old line astronomers said that they were never going to let any machine take over for the human hand and eye, that they were better at it than any machine could ever be. When young people started to observe they found it was really a tedious job, and a machine could probably do it better. -
It was definitely divided that way; the younger people were talking about automation?
Yes, it was very obvious when I came to Pasadena that they understood rotating machinery and control relays and push buttons, very, very well; but anything that involved electrons and vacuum tubes and photo cells was a strange new world. Well, I have to except Sinclair Smith who had been trained as a physicist at Cal Tech; and he knew about these things. But most people didn't. And I was the wild young man who marched around the mountain carrying a soldering iron. "Wild young man" is perhaps wrong.
How were you regarded, then?
I don't really know. I think — yes, I think I was respected.
Were there ever just any long smiles on the face of, let's say, Walter Sydney Adams, about some of the things you were doing?
I don't think so. Not that I know of,
There was never any question or discussion or debate about the effectiveness of the reliability of photoelectric devices, as compared to photographic or visual means? Did you ever encounter any — maybe not skepticism, but concern over that?
Well, as long as the photoelectric specialists ran the equipment, the record of reliability was good. But I think we always had to combat the difficulty that photography could go much fainter than we could. This limitation was not passed until after the war. Then probably Bill Baum was the man who proved that we'd gotten there.
Did you know Bill Baum when you were at Mt. Wilson?
I didn't know him until after the war. He didn't come until then. Then when Bowen became director, he decided to devote one post to that kind of work, and Bill Baum was a recent Cal Tech PhD in physics. Bowen had known him at Tech. And so, that was how the post was filled.
Did you see a real change in emphasis, when Bowen replaced Adams, when Adams retired? This is also jumping ahead a bit.
Well, yes. I think so. But Bowen was also a Yankee. He came from upstate New York, not so far from where my grandfather did, but he brought, in my judgment, two things. One was, superb knowledge and instinct for what were the limiting factors in optics and gratings and spectrographs. His essays on this are still about as good as anything in print.
In Stars and Stellar Systems?
Yes, and his Russell Lecture to the American Astronomical Society. Most people say the 200-inch wouldn't have gotten in commission and working anywhere near as fast as it did, if it hadn't been the hands of a person with physics training, and instinctive feel about optics. Bowen was responsible for that. So he was responsible for the modernization of all the spectroscopic equipment and design of all of the auxiliary optical instruments for the 200-inch. And the other thing is that he felt that there must be a connection between nuclear physics and astronomy. He didn't know exactly what it was, but he wanted to give all encouragement to it. Indeed, understanding the evolution of the stars via the open clusters was the flowering of that concept, and I think Bowen was personally responsible for fostering that. But it just blossomed all over.
That was Sandage and Schwarzschild.
A good deal of it. A good deal of it was. And Harold Johnson. But it blossomed all over. As a matter of fact, Eggen started doing it at Lick, and he was a little bit early for the proper nuclear results, and of course it was a good deal before the Hoyle and Schwarzschild unraveling of it. And I think I recall that Geoffrey Keller had something to do with it, along the way. Understanding what happens when a star stops being a Main Sequence star, and changes into a giant, that unlocked the whole business, and that came in the early fifties.
That's right, already in the fifties, even though we had the Shoenberg-Chandrasekhar limit in 1942, had the Bethe CNO cycle in 1938-39, it was over a decade or so before all these other problems were unraveled. But we're getting ahead of the game. Why don't we go back, as much as I am interested in evolution.
I'm afraid this is a rather grasshoppery trip.
— Yes, well, I want to get a little more chronological. We'll go back then to your years as the NRC fellow, and how you returned to Wisconsin. Was this pretty much again the doing of Stebbins? Did you have any other feelings? Would you have liked to have stayed at Mt. Wilson?
Well, I think you have to recall how jobs were in the mid-thirties. Nobody was beating down my door with job offers. I wasn't weighing any competing offers at all. And I think my sense of what I could do and what I wanted to do hadn't jelled sufficiently, so that I was just in transition. But the work with Stebbins, and what we were able to do together in the late thirties, at Washburn and on the trips to Mt. Wilson, finally cemented in my own mind the commitment to being an astronomer. But the support and the advancement that I got was Stebbins doing and was a very large part of that transition. It was natural just to keep on going. I didn't want to do anything else.
We're just back from lunch, and during lunch you discussed a very interesting experience that you had, seeing O. Struve for the first time, when he came to Wisconsin to give a physics colloquium. I know it's difficult, but I'd like to ask you to go through that again.
Yes. I remember it quite clearly. It must have been about 1928, possibly 1929. Struve came up from Yerkes to give a colloquium before the physics group, and it was a time when he was just becoming interested in interstellar gas, as revealed by spectrum lines. It was also a time when the high abundance of hydrogen in the universe was just beginning to be realized. He started out the hour by saying that there were two estimates of the average density of hydrogen in interstellar space, and that they differed by a factor of 10. Then he began to cite the physical arguments, plus the fragmentary observations and his own speculations. The figures flew. He wasn't a very well organized lecturer, with a nice outline developing on the blackboard. He flew over to one corner of the blackboard and wrote a few figures and made a little diagram and a small calculation, and came back to talk some more. Then he raced to another corner of the blackboard and did the same thing over again. And so the blackboard was pretty well covered with figures at the end of the hour.
But as a result of all the revisions and additions that he'd been able to bring to heart he had gotten the disagreement down from a factor of 109 to a factor of 103• He said, "Well, while this isn't perfect agreement, in view of the remaining uncertaintiest I think we may view the subject with some satisfaction." The physics students were restrained and did not laugh at that, but I think they all thought that astrophysics wasn't a very exact science. Years later, when Struve was leaving Yerkes to come to Berkeley, there was a going-away dinner at Yerkes. In some of the after dinner remarks, I reminded the company of this first recollection that I had of seeing Struvet and said that I realized later that, while the numerical agreement hadn't been completely satisfactory, I was seeing a very brilliant mind at work. In these early explorations of interstellar spaces, he saw the implications, and the various ways that the physics of the situation could lead to explanations. And this, being in at the birth of these concepts, was something I should treasure. Later on, he thanked me for the kind remarks and said it was one of the nicest things that had been said.
Do you recall any of the arguments he used?
No, I'm afraid I cannot, now.
OK. Particularly on the very high abundance of hydrogen, was he citing any of Russell's work?
I don't remember at all.
OK. It certainly is an interesting recollection. Did it get you interested in the interstellar medium, or did the great disparity excite you or what?
I think this was probably before I first began to work with Joel Stebbins. Well, I knew a few things about astrophysics, but it was too early.
Did you have subsequent contact with Struve?
Yes. All during the years I was in Madison, we had very friendly relations with Yerkes Observatory; during the years that Struve was there, we often went down to colloquia at Williams Bay. It was less than a two hour drive. And in various other ways, on advisory panels for things like that Office of Naval Research —this office administered the support that the Navy gave to astronomical research immediately after the war before the National Science Foundation was set up. I recall one other humorous incident, if you want to tape it?
There was a meeting in Pasadena. I can't remember what panel it was. It might now have been the National Science Foundation. The meeting was in the Old Green Hotel, which was a faded watering place among the early turn-of-the-century places, popular when Easterners came to California for the winter. It had an elaborate dining room, with vaulted ceilings. Peter van de Kamp realized that he was at one focus of one of these sound mirrors, and Otto Struve was at the other. He arranged himself at this other focus, and during a pause in the conversation, he started speaking Russian. Struve nearly jumped out of his chair, to hear this Russian coming down from the ceiling. As you know, Peter van de Kamp was rather puckish. He liked to do things like that.
Certainly sound[s] humorous. Why don't we then start with your return to Madison, because we’ve covered things to that point, and keep in mind the contacts with Yerkes and with other observatories as Madison grew, especially in your own career, as you became more and more involved with the organization, on a national level, of astronomy. And also the other theme, very important theme, in addition to the growth of the department at Wisconsin, the growth of photoelectric photometry, and how you came to apply the photomultiplier technique. If we could carry this up to about the time when you went to do war research at MIT, that would be a good segment of time to consider now.
Yes. Well, the early multipliers, in fact any hopeful photoelectric cell of any kind that could be acquired for tests, were just part of the continuing program that Stebbins wanted me to carry on. And I was looking for things myself. And we got a one stage multiplier which helped some, but it wasn't immediately applicable. Then there came the first multi-stage one from RCA, made by Vladimir Zworykin. It had a cesium oxide cathode and cesium oxide multiplying surfaces. It was magnetically focused. And while we didn't apply this to stellar photometry, it was used with Gerry Kron in the first star guiding device. This was only a demonstration device, and worked only in one coordinate.
That was in 1937, then?
I think you have the date correct, but I would have to look it up.
I have the paper here. Review of Scientific Instruments, "photoelectric guiding of astronomical telescopes", A.E. Whitford, Gerald Kron, March, 1937.
Yes, OK, you got it.
I'm interested in how you became interested in that technique, and also how Gerry Kron came to work with you. Was he on the staff?
No. I said that Stebbins resisted starting a full fledged PhD-granting department at the University of Wisconsin. But he accepted some students for the Master's degree, and Gerry Kron was one of them. He was a Milwaukee boy, and came over from the branch campus in Milwaukee, to finish his work in engineering on the Madison campus. He had always been very interested in astronomy, had built a telescope, and was a gifted and very skillful machinist. He decided astronomy was more interesting than engineering, so he began studying astronomy at the observatory. We became good friends, and it was a natural collaboration, of his instinctive gadgeteering and mechanical abilities, and what I knew about photoelectric measurements. Here again, Stebbins said, “Well, here is a boy who ought to go on, and we'll send him off to a place where he can get a broader training”. So Stebbins sent him to Berkeley, where he finished his work for the degree. He went into photoelectric astronomy, and built the first consistently used photoelectric photometer at Lick Observatory.
That was not the first consistently used photometer in the United States?
At Lick Observatory. Stebbins had brought one of his electrometer photometers to Lick, earlier on. I could look up the date. This was .at the time he did his work on Jupiter's moons, as a gauge of constancy of sunlight.
Yes, I'm sure I've heard that reference. May I ask you a question about that, for the historical archives? Would the original photometer that Stebbins brought, or the one that Gerry Kron made here or used here be still in existence?
I don't know.
How might I find out? Where they would be?
Well, ask one of the Shanes.
All right. Fine. We were talking about this paper on the guider.
Yes, all right.
If there's time.
Yes, there's time, five minutes more easily.
How was the actual design of the system set up? This is a design that I've seen actually being used today.
Well, it uses a knife edge beam splitter technique. That is still used on the 36-inch, on Mt. Hamilton. The so-called Weitbrecht guider. Except there it is a four-way, two-coordinate beam splitter, with a pyramid, rather than a simple knife edge.
Right. This style here is actually more like the one that Van Altena made at Yerkes.
I'm not familiar with that.
It's a single photocell, where you don't have to balance it, and I'm wondering, and I'm wondering, when you and Gerry Kron talked about the design of this, were you worried about differential intensity? Did you consider multiple photocells?
No. We thought that was too dangerous.
Because you couldn't maintain balance. And — well, Weitbrecht made it work, but it took skill.
Also, technology in the 1960's.
Yes, and much better multipliers. But up to the time of the war, multipliers were not in regular use. And, if we may pursue the introduction of the multipliers. A multiplier of the modern trip was announced just at the opening of the war, by some people at RCA, and this historical review that I said I would give you from the Handbuch Der Physik which will give you the reference. But the new multiplier did not immediately find its way into astronomy. They were of course made in large quantities for war applications. When he returned to observatory work, after the war, Gerry Kron actually got one into a photometer, and on a telescope at Lick Observatory, earlier than anybody else.
Was there any contact, or growing contact with war and defense interests, in the late thirties? In regard to the use of photo cells and single stage photomultipliers? Did people start approaching you from the government at that time?
No. As you know, the traditional way that some of these technological devices have gotten into astronomical use is that somebody saw a military application, and was willing to pour in the funds for industrial research support, usually on a classified basis at first. And then, the trickle-down to more purely scientific applications occurred later on. I'm not sure, but I suspect that was what happened here. I don't know the facts, and someone who knows the early history of these developments might be Albert Rose at RCA.
Albert Rose at RCA? If I understand it correctly, you were involved in looking for better designs for photomultipliers by the late thirties.
Yes. There were three things that had to come together. And they all came together in this RCA 1P21 multiplier. One was a much higher quantum response, and that came as a result of a development in Germany by Görlich of the antimony-cesium cathode. The second was, wider spectrum response than the old potassium alkali photo-cells that were in use for many years. And the third thing was an essentially noise-free system of amplification, which the multiplier chain provided. It can easily be shown that the noises produced in the multiplication process don't appreciably increase the Poisson statistics of the original photoemission. (There are references, again in that Handbuch article, on that point1
And those all came together in the 1P21 multiplier. It required refrigeration, again, to get the dark current down low enough, although, it looked pretty good in the first tests at room temperature. The introduction of the multiplier took a great deal of the magic, of the need for a special priesthood training that practitioners were wont to consider as necessary before the war, out of it. Instead of there being only a scattered band that had this special skill, workers at many observatories took up the technique. It rapidly became the standard way to measure astronomical radiation, at any wavelength that the cathode would respond to.
Right. That's for sure.
So the 1P21 was the first generally used tube. It revoluntionized photoelectric astronomy, and made it, more or less, a standard operating procedure in lots of places.
What I would like to identify, at least for the period when you returned from Mt. Wilson to Washburn, up until World War II, any association you had with the development of the photomultiplier itself.
I thought we spoke of that a little bit before. I said no, it was the technology that flowed down from developments for other reasons. While we were quite willing to try out anything that a small one-man laboratory in the suburbs of Chicago could get up, in general it didn't lead to much, until RCA began producing 1P21 tubes.
OK. So there was no contact, then between your group and RCA in the development of the photomultiplier prior to World War II?
Well, I think they knew of our interest, and Stebbins was personally acquainted with Zworykin, and arranged the loan of this early one, for use to test. But the combination of the big magnetic fields and refrigeration, was something we never surmounted. Nowadays, I guess it wouldn't be considered very difficult to do. But we used an electromagnet that generated quite a lot of jouls heat.
Well, one of the astronomical problems that you found most interesting, and pursued upon your return to Washburn and also the atmosphere for astronomy, and how it was as a member of the staff, working at Washburn, and the possible effect on astronomy of Stebbins' decision to keep graduate astronomy out, if you have any comments on that. It would be good if we could review them now in chronological order, up until about World War II.
Well, it's difficult for me, just off the top of my head, to speak to that.
What was the atmosphere at the university for graduate education in general, when you returned in the thirties?
Well, I think Wisconsin wanted to be a first-rate university. It had that great tradition, blossoming as one of the first strong Middlewest universities under Charles R. Van Rise in the early 1900s. And it was a good college town. The tradition was there. These were times, during the depression years and the years following, when the support from the state was not especially magnanimous, and the university couldn't do all it wanted to do. But I think in general it was a period of growth, and particularly in things like the agriculturally-related sciences. It had never divided into a university with an "ag" campus, and one with a general campus. The feeling that there might be spinoffs beneficial to the state farmers, and the agricultural industry, brought especially fine support to those branches. And so bacteriology, biochemistry, and plant sciences did very well. I would not say that physics and chemistry were second rate, but I don't think they stood out quite so preeminently at that time.
Were you involved at all with appropriations, getting funding, or was this completely separate?
Stebbins managed all that, and managed it very well and very quietly. If there was a "hard knock" one way, he'd find a way to get it some other way. It wasn't anything like the present days of good grants (at least in the past anyway or if not the present the recent past), good grants for anybody who had shown that he had the ability to produce something scientifically, or the promise of doing it. And by modern day standards, you would consider it was pretty much a one-horse operation, I think. But nevertheless, things grew over those years.
Were there things that you could have done if you'd had more support? That you would particularly recall now, let's say? That were dead ends at the time or were at least stalled at the time? For example, the photomultiplier research?
Well, I think we considered the limitations were in what I could do myself, with the cooperation from another advanced student in physics, undergraduate or the like. It was more what we could manage to do, and not the inability to buy something grand. It was more of a day when physical scientists expected to make their own equipment. Generally they didn't know how to do it any other way. Usually you couldn't buy a ready-made piece of equipment for a specialized task. It would probably have been considered a little bit profligate to spend your money that way.
But in the case I'm interested in, I would like to know if you had ideas for a better, more advanced design for a photomultiplier tube, that you weren't able to test out because of limitations of laboratory facilities and funding?
I can't recall that that was the bottleneck. I guess it was time and ideas and talent, rather than money.
OK. How about courses? What courses did you teach?
Undergraduate astronomy, and one advanced undergraduate course, for science majors, what we called "R, D and S" — the Russell, Dugan and Stewart level astronomy at the time.
You used that double volume all through?
It was mostly based on the second volume, the astrophysics part. And that's all that I can recall right now. I didn't have heavy teaching assignments, ever. But not until after the war did I begin to teach a lot.
The other people teaching would have been Stebbins and Huffer?
OK. Then, turning directly to the papers that we have, I probably missed some, but the ones that I at least have some abstracts of, in addition to the "Photoelectric guiding" one that we've talked about, the one that you did with Joel Stebbins on the absorption of space reddening in the galaxy, from the colors of globular clusters. We have touched upon that, but this was a very provocative issue at that time, the degree of reddening. Van de Kamp was working on it, and Greenstein had, for a while.
Greenstein was working from the point of view of understanding what the dust particles did to the light.
Right. Did you have contacts there?
Oh, we knew what each other were doing. When did Greenstein come to Yerkes? It must have been the late thirties?
We established channels of communication right away, and were pretty good friends for a while. And never ceased to be, although, frankly, now we don't often see each other. Picking up the thread from what we were speaking about before as soon as we had the photocell with the wide spectral range (the same type that Hall had used) and had fitted it into a photometer with dry-ice refrigeration and the standard vacuum tube amplifier, we attached the problem of determining the law of reddening. As I said earlier, this started with a slitless spectromet.
It became apparent that we were not going to reach the fainter highly reddened stars with this system. So I started working on the broad-band filter system, that later developed into the six-color photometry. It took some revisions to get the right balance. Finally we had a chance to try it on a good number of stars, and were able to see that it was a system that could be used for spectrometry. This tryout was in the summer when I came back to Mt. Wilson after I'd gone to MIT for war work. I think this was the summer before Pearl Harbor. The MIT laboratory was organized about a year before Pearl Harbor, and I was one of the first few dozen that arrived at the lab. But the fruits of it were mostly reaped by Stebbins, during the war, when I couldn't get off to help him much.
The multi-color work.
Yes. He applied it to the law of reddening with 0 and B Stars, and my name was on the paper. I guess we had blocked it out, but he did the observing and certainly all of the computation. And he also, without my collaborating at all, applied it to some problems like the light curves of Delta Cephei. He later on applied it to the cluster variables, after the war, when he retired and came to Lick. That was one spin-off of the six-color system. But then it was applied to the colors of galaxies. Out of it came the spectrophotometric energy curves of galaxies, for the first time, as far as I know. And this wasn't finally published until 1948. I helped to finish that write-up. It led to this anomalous apparent reddening of distant galaxies. The deductions showed that after we'd made the best corrections for the effect of red shift from these energy curves, galaxies with a large red shift were much redder than nearby systems. The history of the problem is reviewed in my chapter in Sandages STARS AND STELLAR SYSTEMS, Volume 9. So that it won't be necessary to repeat it here. But that was the birth (and finally the death) of what was known as the "Stebbins-Whitford effect". If it had survived as an incontrovertable demonstrated scientific observation, instead of being demolished, it would have been made cosmology impossible. But I think I had as big a hand as anybody in laying it to rest and forgetting it. I remember Stebbins saying, that if it was going to die, it was better for it to die at the hand of its creators. (Laughter)
I have some questions concerning the Stebbins-Whitford effect, and that is, how did you feel when you came upon this reddening observation?
We presented it at an astronomical meeting. I think in Columbus, Ohio, and we didn't take a position, as to what caused it. I looked over the problem of intergalactic dust, and presented arguments at that time against believing it could be that. I forget what they were, but they had to do with total mass. And the idea that it could be of evolutionary origin was, I think, suggested to me by Martin Schwarzschild.
At the meeting?
Just in conversation at the meeting. And I believe that was incorporated in the final published paper, as a possibility. It was a time when the evolution of the red giants wasn't yet explained. The Hoyle-Schwarzschild analysis hadn't yet been made.
When you and Stebbins had realized that there appeared to be this reddening effect, did you realize that it would cause great difficulties with interpretations of cosmological red shifts, and that sort of thing?
No. I don't think it occurred to us. The idea of a time lapse effect had occurred independently to Stebbins, and I thought that it wasn't terribly likely. I can't remember now just exactly why I laid it aside. But Schwarzschild revived an old theory of giants, which was — it goes almost back to Russell that maybe the tip of the giant branch was much higher in the past than it is now — and so we were seeing back to the time—
— to the time when there were more red giants?
— Yes. The idea of the dying Main Sequence stars, climbing the red giant branch, hitting the helium flash, and bouncing back at some tip that is pretty nearly the same, no matter where on the Main Sequence they started from - all this hadn't yet been brought out. So, whatever this giant phenomenon was, it might have been something that reached higher luminosity in the past than it does now, and that could be what we were seeing. That was the idea that Schwarzschild put forward.
This is in the late forties?
— At that time, people were still thought that when the Main Sequence material had been exhausted, the stars became white dwarfs. And the role of red giants was still not understood.
Yes, that's right.
This is very important to be able to identify, because it would have had an effect on all branches of thinking, especially when you're looking at galactic evolution. You're thinking of "galaxies, of course, as collections of stars, and examining their color curves, with the idea that their color indices were an indication of the relative population, the luminosity functions.
People had this awareness?
Oh, you can find a reference, I believe it's referred to in my chapter in Sandage's volume, that Hubble and Tolman recognized the idea, that the look-back times for large red-shift galaxies, or what were then considered large red shift galaxies, were appreciable fractions of the lifetime of known stars. And therefore, there could have been evolutionary changes in that time. We now understand, yes, there have been, but, as B. Tinsley later explained (Sandage had the idea, too) the track on the H-R diagram that a giant follows is not very dependent on its total mass. And so, since most of the luminosity of galaxies comes from the giant branch, it doesn't particularly matter where on the Main Sequence the giants come from. (It turns out that it's a relatively short range that's in question, in the actual lookback time). Wherever they come from they'll do about the same thing. Therefore, the color of a galaxy changes very, very slowly with age. And this has been tested observationally, most thoroughly, by J.B. Oke and his collaborators.
But most certainly, at the time that we're discussing
— none of this was realized, simply because what the giant branch meant wasn't yet understood in terms of the evolution of ordinary Main Sequence stars, not until Hoyle-Schwarzschild took a crack at it.
Right. At the time that you and Stebbins made this announcement, of the effect apparent reddening with distance, what was the general reaction? You mentioned that Schwarzschild had given you one idea, and then you were concerned about intergalactic dust. Was there a general feeling?
— Well, there was a kind of "It can't be true" reaction. And G. C. McVittie was one of those who put .it in print. I guess he had a feeling. But the true explanation of where we were misled was given by de Vaucouleurs within a year or so, and he was right.
There's a reference to it in the volume 9 chapter by Sandage.
But you indicated that you had a part to play in laying it to rest? What was you particular part in this?
Well, that was the thing I tried to get more information on, in my work at Mt. Wilson during the mid-fifties. And I actually measured some multi-color energy curves. It never found its way into full publication. I was trying to do this at about the time I was preparing to go to Lick, and it just didn't get finished. But I finished it enough to show it to Sandage. He was quite pleased. "Cosmology can now go forward", he said, meaning that rapid evolutionary changes were no longer a source of uncertainty.
Did this eventually reach publication?
No. It's referred to. I did make a brief report on it at an astronomical meeting, and Sky and Telescope ran an account of that report. My observation was this: Instead of referring galaxies to as the sun, Stebbins and I had some (or to a G-2 star which we considered to be equivalent to the sun). I referred them to a B star, as a star that had a smooth and unblanketed spectrum, and I did it with more bands. Then most of the effect went away. That was the thing that I did myself. The next step came in the midfifties, when Art Code (who had been at Wisconsin and then came to Cal Tech, and then went back to Wisconsin), and I collaborated in building a spectrumscanner to go in the Mt. Wilson telescopes.
This was one of the first spectrum scanners, wasn't it?
Yes, one of the first spectrum scanners. Code was the one who actually scanned the first galaxies, and the publication is referred to in Chapter 9 in the Sandage volume.
A 1959 publication. Then it was quite clear that the galaxies were like giant stars; their energy curves had a precipitous curvature, or drop-off at about- 4000. And broad-band photometry doesn’t work well, if you have just half of the filter band filled with radiation, and the other part sawed off. When the red shift moved this guillotine through a filter pass band, the smoothing that we had had to assume for these broad band six color filters, just wasn't permissible. And this explains the effect.
OK. Then the things that I was interested in identifying were, first, whether you had any immediate feelings as to the effect upon cosmology, and you've answered that—you did not, when you saw this effect.
That's right. But I think that all along I had a good sense of the Hubble, and later the Sandage approach, to cosmology. The Hubble approach, of course, was via the galaxy count method, a method which Howard Robertson later showed was not sensitive enough to give an answer. Robertson was a Cal Tech cosmologist. The Sandage approach was via a test of the linearity of the red shift law. But both depended on good magnitudes. And so, that was the motivation for trying to straighten out the stellar magnitude scale, at the faint magnitudes, and for trying to get magnitudes of red shifted galaxies that went as faint as we could go. Later Sandage and his collaborators took up photometry of faint galaxies by the photoelectric method and have turned out most of the modern data.
Again, this is coming up to recent times.
OK, let's move back into the thirties to a paper on instrumentation, but instrumentation though on an entirely different problem. This is your paper in 1939, "Photoelectric Observations of Diffraction at the Moon's Limb", for determining the angular diameter of stars. How were you led to that project?
I wish I could remember.
I have part of the paper here.
Yes. I took it up again after the war when multipliers were around. I think it was just a "tour de force" to see if we could do it. We thought that maybe we had the signal-to-noise [ratio] to do it. And I kind of stumbled onto the diffraction angle of it in midstream, but it hadn't originally occurred to me. Actually Eddington had called attention to it many years before.
There had been some previous attempts to look at stars and determine their angular diameters by lunar occultations. People always felt the seeing was too difficult a problem to overcome, and there really wasn't a detector available to take such minute readings.
Well. I'm sure that the idea of getting stellar diameters -that way went back many years there. And when we saw that, yes, we could get diffraction fringes. Why then a certain amount of analysis went on to block out the problem. There was more analysis after we got more god occultations but that was never published. I could probably dig out this abstract but you've got it.
It was in "An American Astronomer's Report from SKY AND TELESCOPE, which is an abstract of your work in 1945 and '46. That's the one. (Also abstract of a report or paper at an AAS meeting: A.J. 52 (1947) 131)
Yes. It's one of those subjects that maybe was ripe for further exploitation. It's one of those things that I could have pursued and didn't. You know as you look back. We left it for someone else. There were a few other observations in South Africa over the years; David Evans made some of them. When Evans came to Texas, he took it up in a vigorous way and he had some instrumentation that Ed Nather had gotten together with high time resolution and computers to handle the data.
You had to have a way of getting a very quick response.
Yes. We had an amplifier that was good to about, oh, 2 milliseconds or something like that. They did better than that, of course, the finer you slice it, the fewer counts you get, and you finally bite off your own tail. Then the computer will sort out the best mix of how long a time you have to take an order to get enough counts versus whether the diffraction pattern is being blurred by taking too long a time. And I think we were satisfied that we were making a pretty good compromise on the knight stars we took. We thought we were not losing very much information.
It was a pilot study.
Just a tour de force, and our conclusion from this postwar study with the multiplier was: yes, it was possible to determine star diameters of the stars were big enough to smooth out the diffraction fringes appreciably from those that would be expected from an essentially point source. And we saw that while a big telescope helps to get a good signal-to-wire ratio, too large an aperture would blur the diffraction pattern. The 100-inch, which we used, was about the upper limit. But it wasn't pursued. Now it is a fairly big program at several observatories. Star diameters are beginning to accumulate.
That's an historical topic I'm interested in. Well, let's move back to your war years. I don't know anything about what you did. I have not been able to find any published records.
Well, there are one or two short contributions in the MIT Radiation Laboratory Series, the so-called RADAR HANDBOOK. But of course most of the things that were done during the war were classified technical reports. I didn't write very many.
Well, I'd like to know then what your participation was in the project. How you came to the project.
All right. I think it was during the Christmas vacation, at the end of 1940 that E.O. Lawrence came to Madison, and met with a number of physicists. And I was invited because I was supposed to know something about electronics by this time. (I never really did.) It was not explained what the project was, just that it was something that had developed between' British scientists and US scientists that was vital to the war effort. It was not long after the fall of Dunkirk, and the air Battle of Britain in the fall of 1940, which had been a very narrow squeak. Roosevelt was trying to find ways to aid Britain, which stood more or less alone against the Axis powers. There was going to be this laboratory at MIT, and Lawrence really couldn't tell us anything about what the work would be like, except that our experience would be valuable. Of course, our curiosity was just overpowering. And there was a certain amount of euphoria, a feeling that you had been selected as having something that somebody thought was worth putting to work, some knowledge or skill.
What about the feeling that you wanted to participate in the war?
Yes. I think that was strong.
Amongst your colleagues?
Yes. It wasn't just putting things to work. We are all genuinely scared that the Axis powers would win, and then "Heil Hitler". DeVrokin: Yes. Did Lawrence emphasize this possibility?
It was well instilled in everyone, by that time.
I don’t remember whether he said anything particular about it. There may have be some allusions to the critical situation.
Did he talk at all about some of the other projects that were being generated — in other words, other groups of scientists disappearing in the direction of Chicago?
No. We didn't know anything about that. Well, I asked Stebbins if I could go. He said, "Yes, I think you ought to, if you want to, and they want you." So I went off to an astronomical meeting, somewhere around New York, and then went on to Boston. It was in a hotel in New York that I met a guy named Louie Ridenour. He was a Cal Tech physicist, now dead, whom I'd known very well in my post-doc days. He told me what it was about, that it was a centimeter radar.
Was he supposed to tell you this?
No, he wasn't. He was already in the effort. He wasn't supposed to, but he said, "Since you'll be finding out all these things tomorrow, or next day –" And he emphasized secrecy.
Well, I found myself head over heels in radiation physics, and a kind of electronics that I wasn't especially prepared for; but I got in and tried to learn, (as everybody did), as much as I could.
How did you feel about this particular line of research? Did you see the military role, military importance in it?
Oh, yes. The way it was presented to us was this: the Nazis finally couldn't subdue Britain by daytime bombardment, and they were taking up night-time general bombing of the cities, and that was a great peril. But, based upon the success that the British had had in using meter radar to fend off the Luftwaffe during the daytime attacks, they saw considerable hope of dealing with the problem if they could develop centimeter radar. So that was how it first started: airborne centimeter radar was supposed to enable night fighter planes to "see" the boulder [bomber?] and shoot them down. I don't think it ever really worked in a decisive way. But the applications just multiplied and to my mind there's no question that centimeter radar did make a real difference in the war.
What was our participation? How did the research group develop at MIT? You were one of the first in the group?
Yes. That's right. It was, I would say, a very small organized laboratory. It did not have the extreme compartmentalization I that the much more secret nuclear bomb research had. While that effort had a wealth of talent and the bomb did succeed, everything worked there was dissension in the ranks, as I understand it, because of this extreme compartmentalization.
But that was not the case here?
No, except for one or two things, so-called radar countermeasures, and things that had direct spy and espionage aspects. They were super-secret matters, that we couldn’t all know about; but otherwise we had the run of the lab. Once you were cleared, you could know about anything that you wanted to know about. We were divided into responsibility groups, and I was assigned to the Modulator group, which was supposed to make the machine that delivers the pulse 500 times a second to the magnetron. This was the British invention that made centimeter waves of high power, and it was the invention of this, just at the beginning of the war that made the whole project possible.
Who was the person or what was the agency that decided what part of the group you would work in? How did they determine that you were best suited for the Modulator group?
I don’t know. There were people who had learned how to handle these extremely short electromagnetic waves. A good many of them had been associated with I. I. Rabi’s group at Columbia, because he was interested in exciting molecules with these waves. It included people like Jerold Zacharias, Norman Ramsey, and Ed Purcell, at Harvard, and some others at MIT. But the point was, what was known as RF, radio frequency, the generation and transmission and the detection and recording of these waves — the optics, dishes, feeds, the like, was something I had no remote connection with. So I suspect that the general brute force electronics that was apparently needed in this Modulator group, appeared to the organizer to be something I could step in and do.
Who were the other people in the group?
Well, the early leader was Milt White who had been at Princeton (retired now). The place was just flooded with alumni of the Berkeley Radiation Lab, the Lawrence Group. White was one of these.
Was Lawrence actually there?
he was never at the Lab very much. Lee DuBridge was an excellent director. He had some pretty good sub-chiefs. F. W. Loomis, of the University of Illinois, was assistant director, but he was just a wise administrator, and a very good personnel manager. Well, you could pretty much call the role of the bright physicists of that day, and many of them would be there. Julian Schwinger was one.
who were people that worked for you.
G. N. Glasoe, later. I'd known him at Madison, and he was later a figure at Brookhaven. And Kenneth Bainbridge was one of the early ones, a physicist at Harvard. He was the one who introduced me to the problem. My assignment was to make a pulser that would be light enough to carry in a fighter plane, and would deliver quite a sock. It was called the vest pocket pulser. It wasn't quite that. We had many problems, but we did get airborne radar going for a year or two.
What was it like, working under military conditions, and the secrecy? Did you bring your wife? You were married by then, you were married in '37?
Yes, and we had our first child. I never told my wife what I was doing.
But you had moved?
Yes. We moved to Massachusetts. Our two later children were born there. Well, it was kind of a fun group. I think I worked terribly hard. I went back to the lab many evenings. But the morale was high, and beginning about 1943, there were enough successes, real triumphs, to make us believe, yes, we were getting some results that were affecting the war.
This triumph was a direct result of the centimeter radar that the entire group was working on.
Yes. Somewhere along there, key people began dropping out of sight, to some post office address in Albuquerque, New Mexico.
Did people start wondering?
It was secret but I found out, because there was a leak under the secrecy umbrella. Somebody talked to somebody.
I'd be every interested to know how you found out.
Well, I spent sometime in England in 1943. And there were just allusions, here and there, to something that they were awfully scared that the Germans would get going, that would be just catastrophic.
Who were you talking to? What types of people? Other scientists?
Yes. I can't pinpoint that from present recollection. Howard Robertson was a scientific liaison officer in an office in London, for the OSRD (Office of Scientific Research and Development). He wouldn't be the one who had told me, but he would have known about it. I can't remember for sure but I think it could have  been one of the British boys in the lab that I worked in. It was a British laboratory I was working in, TRE, Telecommunications Research establishment, Great Malvern. It was the analogue of our lab. Then about the end of the war, there was something called the British Branch of the Radiation Laboratory — BBR — quite an establishment. I was one of the people that went there early to work on a particular project. I can't remember whether it was one of the British people, or if it was some RAF person, or whether it was just talk in the London office of our laboratories. I wish my memory were better. And so I had a kind of a worry. It was later, back at MIT at some garden party in a long laboratory people that a colleague who knew told me what it was about. I can't remember the name of the guy. You recall there was a sense of urgency in the bomb effort. There was thought possibility that the U.S. wouldn't get there first.
They thought there was a possibility that the Germans would get there first?
Well, yes, up to the time of the German surrender. Then they stopped worrying. And then came the decision, do we fight the war with Japan conventionally or with the bomb? And Truman was persuaded that we should bomb. It was later found out that we didn't have to.
That's true. You then learned first in Britain, that not only were the Germans believed to be working quickly towards a super-bomb, but that the Americans in Albuquerque were also?
No, I didn't learn that in Britain. That was after I got back, some time in 1944.
And this was back at the MIT lab?
What was the general feeling, not only on your part, when you learned that such devices were being developed? Can you recall the general feeling of the people that talked to you about this unknown project? Was there fear, apprehension? Or hope that we'd get there first?
I guess there was the feeling that there was no other way but full speed ahead and to get there — particularly while the Germans had not yet surrendered. But I remember that the Smythe Report came out very shortly after the Japanese bombs. And of course, there were people who had been there at the Trinity tests in New Mexico circulating back, and they were free now to talk about it, or felt freer. And the awesomeness of it impressed us, after we learned and all the things that had gone on in the Manhattan Project. It was a new different world, a dangerous prospect for the human race. This was very much realized, in the late summer and fall of '45. I think our laboratory was due to go out from under secrecy, on the day that it was announced that the Hiroshima bomb had been dropped. So ou~ triumphs got sort of blanketed in the public press, but that didn't matter very much. Then came the dismantling of the laboratory, and preparing the books that tried to write down the accumulated experience and knowledge. I guess they had a similar project at Los Alamos. The bombs were all unclassified. It kept a lot of us busy until early 1946. I left the first of February. I certainly learned an awful lot of electronics, a lot of physics, and an awful lot about how to make a "gadget" that was solid and well engineered, and not home made. And "jury-rigged" devices we were used to in our laboratories. The first thing that a physicist had to learn about making things for the military was that these things had to stand up in the field, with GI's working on them, and blasting going on nearby — warfare in fact.
Was there feedback from the military?
And how did that reach you, directly from a military liaison?
There were liaison officers from all branches of the military in the laboratory, and vice versa — the laboratory went out to the military bases in the US to test equipment. The British were able to test things in the air, above Britain and over Germany, as soon as the scientists had finished twisting the wires on them the night before. The US couldn't do it that way. At least the armed forces didn't think we could.
Why not? It would be too obvious?
No. The equipment just wouldn't stand up that far away from its "creator". Too much jouncing around. Too many "non Marlins" having to handle it along the way.
The British were much more "seat-of-the pants" then?
Well, it was a much smaller operation, much closer to the actual military use.
Which did you prefer?
Well, I think the physicists came there wanting to be "do-it-yourselfers", but I think that in the, end they all recognized that the military was probably right.
Was this your first experience, then, with large scale team research?
And do you think that the techniques of cooperation, the development of instrumentation in this particular experience, pretty much was a positive aid for you in your future career?
Oh, I think I learned a great deal. But as far as ways of operating, I went back to a world where the money didn't flow anywhere near as freely not until later on. And then, I was by this time fortyish or beyond one's tastes and upbringing were a little too hard to change. One could see the wave of the future coming, and it's now come.
You could see that there was going to be increased support?
No. One could see that astronomy was going to become more and more enswathed in high technology. That it wasn't a matter of taking a plate out of the deep freeze, warming it up and mixing your own developer, and coaxing the telescope into good mirror shape somehow, by opening and closing domes at the right time, and then exposing a plate with high artistry, — "doing it yourself." Real mastery of a beautiful and sometimes cantankerous instrument, a big telescope. And the old line astronomers had admired the virtuosos at that game, and I still do. But the technology which is put at the output end of the telescope has gotten far too complicated for that.
You realized this after you returned to Wisconsin?
I guess so.
Probably you would have been one of the first to appreciate just the possibilities of more sophisticated electronics, instrumentation, at that time.
Oh, I think you're putting forward ideas after the fact. No, I don't think I was particularly bold or venturesome. It was just the next step, with apparatus that I more or less had to build myself, with limited resources, each year, until the end of my days at Wisconsin in 1958. Then other responsibilities intervened, and personal astronomy played a secondary role for a decade.
That was your administration here at Lick.
Yes. DeVork1n: Well, going back to the war years, you knew, I assume, that there wasn't any question but that you were going back to Wisconsin? Or did you have any other ideas in mind?
Well, at the time the laboratory was being dismantled, there were a lot of jobs floating around, in industry, in government-related laboratories, or military-related laboratories, and an offer or two or three did come along. I could have gone to a university as a physicist. I don't know why, but I could have.
Which was this?
It doesn't matter now, but at the time this fact didn't do any harm to what Stebbins was trying to do at Wisconsin, to take my pre-war frozen salary, and lower academic status, and get them both updated.
Had he been fighting on your behalf for that?
I wasn't an exceptional case. It had been university policy that they were not going to promote people while they were on leave. I think that's a general policy with every university. And all the universities realized the facts, of life, after the war. It came at a time when most state treasuries were bulging with tax receipts that they hadn't been able to spend. At any rate, I got promoted when I came back.
You were an associate professor for only about two years, though. There was a very quick promotion then to director when Stebbins retired.
I guess that's right.
Do you know how the choice of yourself as successor to Stebbins was made?
Well, I didn't seek the job. I waited for them to ask me. I guess I would have been prepared to continue in the same vineyard if someone else that I reflected had been chosen.
I like your terminology.
But I’m sure that the dean, and I think the president, took a hand in consulting other astronomers. I do know that I was favorably spoken of, but I don’t know by whom. Stebbins never told me. So I was offered the job. Well, there’s always a certain euphoria that comes with such recognition. It is unfortunate, I think that it does, looking back. So I took it.
Some of the first research that you engaged in when you came back was the long project on the detection of the bulge of the galaxy in the infra-red. Is this an idea that you had had during the war, or before the war years, or something that Stebbins had in mind to do, to detect the nucleus of the galaxy?
We did a joint project. I'd have to look up the date of the publication. I can find it for you.
The publication itself, on the galactic bulge?
Yes, the one we did at one micron. This is "Infra-red Radiation from the Region of the Galactic Center".
That again was the summer of '46, and it was reported upon at the 75th meeting of the AAS.
Well, that was the one we did jointly. And then, there was another abstract, covering my trial at two microns with lead sulfide. It was never published in detail. I don't know whether you have an abstract on that or not.
No, I don't believe so.
Well, I can find it for you. That was done at Lick Observatory with a searchlight mirror. It was probably the summer of '47.
You were at Lick for a while?
Yes, I spent the summer there. The southern sky was darker than at Mount Wilson. The fact that relations between Stebbins and the Mount Wilson Observatory weren't as warm as they had been was a factor also.
I wasn't aware of that. Whitofrd: Yes.
Concerning who had the idea — I think that was Stebbins' idea. We did detect a bulge of radiation, but it was on a six minute scale. Looking back now at the final detection of the sharp nucleus by Becklin and Neugebauer, one can see that it would have been blurred and shorted out at the course scale we were using. And indeed, it's very doubtful if anything much would from the sharp nucleus would have gotten through at one micron, on account of the enormous absorption. In the second attack, with lead sulfide at two microns, using a searchlight here at Ht. Hamilton, we took in about a square degree at one time. The bulge was there, and it was there in the right place, but by analogy with the Andromeda galaxy, one could see that the concentration of light in the central peak of our own Galaxy would have been mixed with too much other radiation from the surrounding field to leave a perceptible bump. The field of view was too large — one square degree. You see, the focal length of the search light mirror was only about six inches.
I tried to go on with it with a larger telescope, to get a smaller patch on the sky. I was trying to chop in the telescope against a metal baffle, but the baffle was so much hotter than the sky, that I got a terribly large negative signal, when I opened the thing to the sky. And this was bad enough so that when I made a trial on the bulge with the 60-inch telescope, the whole scheme didn't work.
This was later at Mt. Wilson?
Yes. Well it was abandoned. My early venture in infra-red with lead sulfide using the Cashman cell, had led to the first extension of the interstellar reddening curve into the infra-red about 1948. This was one of those things that one can look back on and wish that he had kept going at. People like Harold Johnson at Arizona did a lot of work, and then at Cal Tech Neugebauer — well, it was Robert Leighten first, Gerry Neugebauer, then Eric Becklin took it up. Becklin (with Neugebauer) discovered the radiation from the galactic nucleus. I'm not sure that he ever knew that I had taken a crack at it 15 or 20 years earlier.
Maybe we could ask him some time.
Maybe he just thought it was kinder not to rub any salt in the wound left by the wasted opportunity, if I can mix my metaphors a little bit.
But you did detect a general bulge.
— a thickening of the galactic disc in that general area.
That's right. It was certainly brighter in the infra-red than in photographic light or red light, and brighter at 2 microns than at 1 micron.
You were using infra-red to what purpose, to cut through the dust?
Yes. It came out of what we knew about the general law of interstellar reddening.
What of Baade's work, though, on M31 — finding that the nucleus was red? Had this also aided your decision to use infra-red? What did you think about the galactic center?
We didn't really know, just that there probably was a great intensity peak, analogous to that in M31. And Baade's finding applied to the whole central bulge of M31 as I recall it. It is now known that within the central bulge most galaxies get redder toward the center. It's been known since 1961 or thereabouts. De Vaucou1eurs was one of the first ones to show it. A lot of people have studied it since, in terms of changes in the spectrum, or the spectral indices measuring the strength of prominent absorption features.
But Baade's work did not immediately imply, in your mind, ~hat one would expect the color to get redder as you go into the center?
No. I guess we thought that the color would be the same, but there would be an enormous intensity peak. What made it easier for Beck1in and Neugebauer to find it was the fact that the exact location for the center of the galaxy had been plotted meanwhile, by radio methods, so they knew exactly where to look. And since a small-area detection device could then be used, the sharp nucleus stuck out.
Could you with your apparatus have detected it, if you'd had that resolution?
Well, I'm sure their detectors are far more sensitive than what I used. And they were using sky - versus - object chopping, not object versus a hot mechanical chopper in the apparatus. Thus they had a great advantage in being able to compare one piece of cold sky against another piece of cold sky. Cold, relative to some object, in the telescope, such as a chopper blade.
Right. By this time, you were also very much a family man, and you were back in Wisconsin. I'd be very interested to know, as the new director, succeeding Stebbins, what direction you saw the observatory going in? We can start with graduate education.
Well, I don't think I had very expansive ideas. I don't think the university would have gone for anything very grandiose. They believed in building on strength, and so did I. But I was persuaded, yes, we should have a graduate program.
Who did the persuading?
Students coming around asking, could they study?
Do you remember any students in particular who were applying the pressure?
Well, there was one named Gordon Vandervoort. Last I knew he was teaching somewhere in Malaysia.
Any of them that became astronomers of note that you knew at that time?
Well, John Bahng was one of them that I recall. There weren't very many. We had only two or three graduate students at one time who were really serious about it, and then some other people coming in from physics just to learn more about astrophysics. And, then Art Code came. He's a bright fellow, very well grounded in astronomy and astrophysics. He had studied under Chandrasekhar. He did a lot to help the idea of an expanded department grow and flower. He got hired away to Cal Tech, then came back just at the time I left.
He came as an instructor. The first record I have of him at Washburn was about 1951. Did he come earlier than that?
No, 1951 is correct. We had three faculty positions when Stebbins retired. Stebbins' slot was first filled by Harold Johnsont who came early in 1949t and left in 1950 or 1951 to go to Yerkes Observatory. Then Code came in the fall of 1951. Johnson did a lot to improve the photoelectric equipment and the electronics that went with it.
He came as an assistant [your question] professor in '48 - '49? And at that time Burt Nelson and Frank Blust were also here as research associates. At Washburn?
Johnson was an assistant professor. The other two were research assistant. Burt Nelson is now at San Diego State.
He never got a PhD in astronomy at Wisconsin. He went into philosophy of science for a time. But he's done quite well. You've done a lot of home work bringing up names like Frank Blust that I haven't recalled in years.
It helps to set the stage for a discussion of your early years as director of Washburn — how the policies were set, how graduate education developed.
Yes. Art Code came, and he stayed for about 5 years before he went to Cal Tech. Theodore Roub, a graduate student who had just gotten a degree, filled Code’s shoes, and kept the slot when I left. At that time (1958) Code came back as director. Of course, he had considerable bargaining power, coming from outside, coming from as prestigious a place as Cal Tech. He laid out the plan for a full-fledged graduate department, with ten or a dozen graduate students at the maximum. He began fleshing out the staff with theoretical astrophysicists, and assembled a big enough group to be well above the critical mass. It really flowered, and the whole OAO business was taken up. I must say, that the flowering of astronomy at Wisconsin had its foundations going way, way back, but Code is the one that brought it off.
With the OAO?
Well, just with the whole program.
You said that a chill came into the relation between Stebbins and the Mount Wilson Observatory in the post-war years. What was the difficulty?
When Bowen became director in 1946 there were naturally some changes in time-honored customs. The Carnegie Institution had to think about adjusting to the sharply increased cost of doing research. One of the changes was the wiping out of the permanent panel of Research Associates — senior scientists in general. Stebbins had been one of these since about 1932, and had come to Pasadena regularly - probably more visits than any of the others in the group. At a time when this change was still an internal matter in the Carnegie Institution Vannevar Bush as president wrote Stebbins extending the privilege of using the Mount Wilson telescope again in the summer of 1946. Stebbins took this to be a continuation of the old arrangement. Later after our joint loans had been laid, he found out that there had been considerable change — no Carnegie title and no stipend. He felt that a straightforward statement of the new policy had been due him in Bush's letter. He did not broadcast his feelings of resentment, but he did not forget them, either. And Bowen was not a man to deviate from a policy once adopted!
What happened after that?
This was close to the time of Stebbins' retirement, so it didn't matter very much longer. He didn't want to hurt my access to the telescopes, so he continued on that one summer of 1946 without pay, and we carried out our joint program. By the next summer, he had somehow managed to convince me that a summer at Mt. Hamilton would be a mighty good idea.
Was he looking to Mt. Hamilton as a good substitute for summers at Mt. Wilson, then?
No, I don't think he was at that time. As a matter of fact, he had bought a house in Pasadena, during the times he was coming there every year sometimes for more than just the summer months — and expected to retire there. He enjoyed the camaraderie with the Mount Wilson staff and I am sure the feeling was mutual. He was just a joyful man to have around, a gay spirit, one who enlivened any group with a certain joie de vivre. An inebriate.
Right. How did he feel about this obvious change of atmosphere, then, at Mt. Wilson?
Well, as a result of it, he sold the house in Pasadena. Maybe that would have happened anyway. His plans for post-retirement activity changed when Donald Shane asked him to continue work on Mt. Hamilton. It began with a short-term appointment as Morrison Research Associate at Lick Observatory. After that there were grants that supported a continuing arrangement. During these years, he maintained a home in Menlo Park and commuted to the mountain five days a week.
Commuted on five days a week?
Well, no. He went up for a five-day stay on the mountain, and then returned for the weekend. Once up, once down — but possibly it varied. He added a great deal to the vivacity of the dining hall conversation. He collaborated with Gerry Kron, and turned out some more very excellent papers. But then his eyesight began to fail, and on around 1958, about the time that I was coming, he gave it up. He didn't come back to the mountain very often after that.
But he was still around, of course? for quite some time? *
Until he died in 1966. He lived to be 87.
His stories must have been quite an experience, because he of course knew the mountain as a young student.
He could tell you stories about every bend in the road -who had gone off the road here and there, how somebody had a battery strap there. He knew the names of every natural feature, and the legends about how this thing or that thing got named. It was just an entertainment, to ride up the mountain with him.
Was most of his research funded? You mentioned grants. Were these government grants by that time?
I think so.
Early NSF grants?
You'd have to look at the published record, but I think it was the Office of Naval Research, and also the American Philosophical Society.
Well, let's center on Washburn for the moment, and your work as it progressed through the fifties. How did you choose your problems and your various research interests at that time?
Well, this is about the time when other responsibilities began to weigh me down, and publication rate fell off. We did some work on magnitudes, and we were trying to pursue the implications of the Stebbins-Whitford effect. The project to build the Pine Bluff Observatory came along, about 1955 or thereabouts, and that occupied a pretty large fraction of my time in the last few years I was there.
How did that come about, Did you have the idea?
Well, we had talked about it, with administrators around the university. Then one day, out of the blue, while we were still thinking how nice it would be, President Fred called up and said he had found a way to finance it.. I remember, once when Stebbins came back, going out and driving around the hills, for 20 or 30 miles west of Madison and talking about where the lights would be, and what was just naturally beautiful. Stebbins had a keen sense of this.
The esthetic sense. Of where the observatory could be?
Yes. We actually saw the ridge where the Pine Bluff Observatory finally landed. It's much too close to Madison, though.
Much too close?
Right. Urban growth and suburban expansion came along in a way that was not foreseen.
How was it finally chosen? Did you do a site survey?
No in the modern sense, no. We thought it would be quite unlikely that there would be any large difference from one site to another in cloud cover or seeing, and therefore, we were just considering where the roads were, where the lights were, where the little towns were.
At this time in the mid-fifties, might there not have been a number of different trends in astronomy nationally that would have caused you to think seriously about the relative values of a local observatory like that? I know that Kitt Peak and AURA were still very much just beginning….
Kitt Peak was well on the road, by this time. There was that Flagstaff Conference that really got it started— I could find a reference to it. I had a role in organizing it.
These are some of the administrative duties you're talking about, that kept you from research?
Yes. The model that had worked quite well at Washburn, in my estimation, and I guess in others too, was that of expanding local opportunities by visits to observing centers. These might come once a year if you were lucky. The Stebbins research associate appointment where one was always assured time if one was not to be counted. The freedom to travel and the generous grants that we now consider just a part of doing science weren't then considered something you could count on. It was generally thought that astronomers in universities would be expected to teach a pretty good fraction for most academic years. And so the model that had worked so well during the Stebbins years — a local observatory with a modest telescope, but with freedom to experiment with instrumentation that could be carried to a bigger telescope at a better site — that seemed to be the way for a university to go. Many universities that didn't have the climate that warranted billing a big telescope have felt the need for a local station for year-round use, always available to students. At any rate that was the justification for the Pine Bluff telescope, one of the early rural observing nations established to fit this pattern. It was built at a marvelously cheap price, about $200,000. I suppose some compromises were made that we wouldn't make again, but it was a good experience.
Were these compromises in the design of the telescope?
Yes. It was one of the early Boller and Chuiens models, a copy of the one at McDonald Observatory.
The idea of time sharing at major centers you've pretty much identified as being stimulated by Stebbins' model. But were you also looking at some of the other ones, like McDonald, that were being used by several observatories at that time, after the University of Texas began its own astronomy department? You weren't very far from Yerkes, and I wondered if you had any contact?
I believe Chicago and Indiana had an agreement with the University of Texas. We may have been deterred by the charge for telescope time. As far as Yerkes at Williams Bay is concerned, they didn't have very much in the way of reflectors at the time. I believe they've gotten one since. But a 24-inch reflector in that climate wasn't much of a magnet, and the wavelength transmission and focal curve of a refractor leave much to be desired for all sorts of work.
Would you have been interested in McDonald yourself, going down to use the 82-inch? Had you ever talked to anyone at Yerkes about the use of McDonald?
No. Never did. I took a graduate student to Lowell Observatory once to work there. That was exploring whether we could get time, and whether a visiting arrangement would work out. The first trial wasn't marvelously successful, but that was probably the students fault.
How did the idea of the National Observatory develop? Did it develop in your mind before other people were talking about it?
I don't think I could claim that I originated the idea. It was developed out of discussions in many places, mostly at eastern and midwestern universities. I suppose John Irwin, then of Indiana, might have been one of the earlier advocates of the idea.
He was working with Edmondson at Indiana at that time, who, I imagine, was pretty much involved with the early organization.
I don't really remember how soon Edmondson became involved — he certainly was later on. I think Edmondson took as his first project is Indiana the development of what they had at the Goethe Link Observatory. It was a private observatory given to the university. It had a pretty good sky, but rather primitive instruments. It was Irwin who had been at Lick, did his thesis there, and had been around Pasadena during the war. He saw the possibilities of going to where the climate was good and telescopes worked more effectively.
Did he contact you personally, amongst other directors of observatories, about this possibility?
It was more a matter of informal conversations at regional and national meetings. I can't remember whether there was any formal communications. Irwin’s influence was certainly felt in the growing movement that led up to the Flagstaff conference -be was editor of the publish proceedings.
Let’s complete the years between the beginning of construction of Pine Bluff, and your coming to Lick and your recollection of your membership in national societies, committees, and study groups on the future of astronomy that had started being generated at that time, and certainly, the reasons for your coming to Lick?
Well, following the Flagstaff conference the idea of a National Observatory developed quite rapidly. NSF appointed a committee — I believe it was called a Special Advisory Panel — to consider possible plans. I remember making a report as a member of that committee to a meeting of the American Astronomical Society. I can find a reference to that. Some of the people who served terms as administrators of the NSF Astronomy Program during this period were Peter van de Kamp. Frank Edmondson, and Helen Hogg. A loose association of universities was formed which later because AURA — I can't give the exact date of official incorporation, but it might have been 1956. [Formal incorporation date: 1957] I represented the University of Wisconsin in this organization effort. The committee work involved took quite a lot of time. There were periodic visits to Arizona to look at sites and plan the whole operation, and to talk about personnel.
During this period Huffer was going to Flagstaff if I'm correct, to do photoelectric observations. Did any of his activities help in looking for sites, accepting the use of Arizona as opposed to another state?
I can't recall that it did. He had a long term interest in eclipsing binaries, which was a subject that Stebbins got his start in, with the work on Algol about 1910 or '11. Huffer had various collaborators along the way. One of them was with Zdenek Kopal. And Olin Eggen worked with him while Olin was a graduate student in Madison. He continued his work on eclipsing Gueries, I think, till the time he left Madison and went to San Diego State for his last years before he retired. He had common interests with Burt Nelson at San Diego; he also took up testbook [textbook?] writing for junior college level astronomy.
That's right. I was just wondering if there was a collection between Huffer's work and the National Observatory.
Yes. Well, his interest, his talents, were more toward the use of astronomical equipment to get the data he wanted than the technology of it. He knew how to use a good night when he had one, certainly, but new facilities weren't his primary concern.
OK. Had Flagstaff ever been considered in preference to other parts of Arizona?
Well, there was a long site survey, headed by Aden Meinel, who came from Yerkes. Bengt Strömgren, director of Yerkes at the time, was a member of this committee. Meinel looked over, well, all the Western United States. There had been some site surveys by a couple of boys at Harvard, looking for solar sites (Sacramento Peak came out of that). Harlan Smith was one of them; I think McCroskey was the other. Meinel's survey finally came down to fewer and fewer sites. As I recall it, the Flagstaff region had poorer statistics for clear night hours and good seeing then Arizona sites further south and nearer the Colorado River. There was a site near Kingman that was the runner-up against Kitt Peak for the final choice. Meinel's recommendation was for Kitt Peak, but not by an overwhelming margin. The board had half scientific members. They saw the point, and Kitt Peak was selected.
It was relatively straightforward.
Yes. And there were arguments for Kitt Peak versus a site on the West Coast, which was know to have good sites. Junipero Serra in the Pacific Coast Range South of Big Sur was actually considered as one of the sites, and Leon Salanave actually occupied it. He was very partial to that site.
Who was that?
He was with the Astronomical Society of the Pacific for a while.
Yes. I respected Salanave's work as general officer very highly.
But the argument for choosing an Arizona site was that the feast/famine between summer and winter on the California coast is somewhat reversed in Arizona. The winter and spring especially are the seasons when the galaxies in the North Galactic Cap are overhead. This season is often pretty bad on the West Coast. There are arguments the other way. The thunderstorm season in Arizona comes right at the time when the nights are shortest, or very close to the time when the nights are shortest. The number of nights in July and August with clear sky and good seeing is rather small. Well. I think the notion that I might come to Lick Observatory jelled some time in 1956. Actually, I was approached about the directorship of the National Radio Astronomy Observatory at Greenbank, and this, I guess, more or less stimulated the Lick people to look around after Shane had announced that he wanted to retire as director in 1958. And they decided to see if I really was more inclined to go further east and take up radioastronomy. Of course, it's always stimulating to be offered a directorship at a prominent place.
Greenbank was quite new at that time, still was building.
Who was interested in having you come?
I don't know how my name came up. Leo Goldberg was on the governing board, and he was the one who called me up, as I remember.
This was when Struve was there?
No. It was before Struve. I think Struve was at Berkeley.
Did the possibility of the Lick position look more interesting?
Yes. I was finally invited to come to California to look at the place, and have lunch at the president's house. And it was offered to me, and after some soul searching and considerable wrestling, I accepted, more than a year before I came.
Was this general knowledge at the time?
It was leaking around the astronomical grapevine.
What were the pros and cons of your coming? Were there any people on the staff that wanted the job directly?
I never was made privy to the deliberations. I have heard that various people were put on the list, and then one member of the staff or another would say something against this one or that one, depending on which staff member was consulted. I never knew who they were. I thought that there were available candidates on the staff, perhaps Mayall, and I never could find out why they didn't want it or weren't offered it. From what I've now learned, I think that because of the fact that the 120-inch telescope was so long between its conception, it was felt that somebody who was good with telescopes and apparatus, which I guess I had a reputation of being at the time, was what the observatory needed. And so I was probably the only one they could agree upon. That might have been the case. That's all I know.
Certainly it was one of the major positions. And the choice of a successor to Shane must have been carefully made. How did you feel about taking on this responsibility?
Well, I guess I felt I could do it, or I wouldn't have taken it. And the fact that somebody else thought I could do it perhaps encouraged the euphoric feeling that I've previously mentioned. Do you remember those Toynbee books about challenge and response? The rise and fall of civilizations? I guess it was just part of the ethic in which I had grown up: to spurn a challenge for either fearfulness or personal comfort or for just whim was not being very resolute or bold or courageous. And of course there was quite an increase in salary. I think the idea of living in a huge house and carrying on some of the official entertaining — pageantry or what not — that traditionally goes along with the job, was not especially attractive. And it certainly was not attractive to my wife.
It was not?
Well, how about the feelings that your family had? Your children must have been close to college age at that time?
One son was in college. The youngest girl was still in elementary school.
This must have been a very big change, not only moving from one climate to another, but moving to the top of the mountain.
Yes. California wasn't strange to me. I had visited the Lick Observatory many times. I'd spent one summer there. And I guess I thought of it as the runner-up to a place that we all thought was the capital at the time, Mt. Wilson-Palomar. I still think that's a very great place. Well, the family adapted all right. I think that's about all I could say about it. The job was a compliment which made one feel euphoric, I guess. Too, it was a challenge. And I felt that it would be a little unfair to myself or to my ethic to say "I won't have it".
Well, in meeting with the president, and probably by that time a number of other officials of the university, what were some of the issues that were raised? What did they want to see the new director of the observatory so, as far as cooperation with the other campuses, cooperation with the university, funding, that sort of thing? Was Clark Kerr there by that time?
No, the president was Robert Gordon Sproul. And of course, that meant there would be a later change that I couldn't foresee, because Kerr had not been chosen yet.
He had not been chosen?
Yes. Oh, I think everyone knew that Sproul was nearing the retirement age.
Really? People knew that?
Yes, you could look up Sproul’s age in Who's Who. He actually retired on the date that I came to begin serving. I had been to see him a year and a half before. Kerr was chosen president in that interval. He had been Chancellor of the Berkeley campus. Well, Sproul had done a great deal to make possible the promise of the l20-inch telescope — which was a very great one. I think he wanted, and the university wanted, and certainly everyone around the observatory wanted, I wanted, too, to make it produce, and to realize the great potential in it. And it was felt that it would be a revitalizer, would greatly increase the opportunities, that it would attract good people. It was a time when the university said a good deal about its commitment to excellence. There wasn't anything much said, that I recall, about the Observatory being a university-wide facility, and of course for years it had not been that, because it didn't have a tremendous lot to offer to people from Berkeley that they wanted. Of course they sent up students. Not many of the faculty members came themselves any more. Berkeley was the only graduate department at the time. And so, I take it, the general concept that I had, and I thought it was the one that Sproul had and the university had, was that Lick was a research institute which did research of quality, mainly with its own staff. People from hither and yon, inside the university and out, who wanted to use the facilities should be accommodated.
But there was no inkling at that time that things were to change in another five or ten years or whatever?
Yes, that's right.
I'd eventually like to get the development of your years at Lick in greater detail, but I'm sure you don't have time to do it today. Do you have anything else to say about your coming to Lick at that point?
Well, I remember that I paid a visit to Pasadena for an observing session, within a month or two after I had said I would come. I guess it was the spring of '57. Shortly after I arrived, Ira Bowen came to see me, and said that word had reached him that I had accepted. He congratulated me, and said that he hoped that I'd felt that the cooperation that had always existed, North and South, between Lick and Mt. Wilson — and it was quite strong — was still an open channel. He said he wanted the cooperation to continue. This was a nice gesture. One comment that I could make was that for a while I didn't realize, even after I came to Lick that the place of the Observatory in the general structure of the university was going to be different after Robert Gordon Sproul retired as president. Sproul is generally agreed to have been one of the great presidents of the University of California — he was a business officer, originally, as you know. But the buildup of science on the Berkeley campus in the Lawrence era, and that of many other departments, was due to his skillful guidance and his good relations with Sacramento. And he and Donald Shane and some of the people around Sproul, in what then became the state-wide administration were very close friends. Sproul had a very warm spot in his heart for Lick Observatory, and even wanted to call it a "campus". There were pieces about that time, written by Olin Eggen, calling it "The University's Highest Campus"*.
What did Eggen write those for, for A.S.P. Leaflets? He sounds like quite a character.
No, it was a University of California publication, I think. Eggen is going to Cerro Tololo in the fall. He's leaving Australia.
Does he have a staff position?
Yes, a senior staff position.
Obviously this Sproul relationship with Shane was good.
Yes. And one of the quotations that Don Shane used to cite was that Sproul thought that Lick Observatory was an "ornament to the university, an expensive ornament, but one that we can afford".
That's a good attitude. Did you talk to any of the people at Berkeley or UCLA at that time, when you decided to take the position?
At that time was Struve still there or had he left?
Yes, he was. Well, established relations after I'd come, but I didn't go talk to him before that, as I recall. The attitude of the administration of the university toward the observatory had swung in a quite favorable direction during the Sproul years, just because of his affection for the place, his good relations with Don Shane. No doubt, this did some good. Some of the adjustments that came later were a reflection of the fact that this special relation was perhaps a deviation form the normal attitude that the president of the university would be expected to have.
Where did these feelings come from? In what part of the university did they have their origin?
Well, we'd have to get over to the difficult years of Lick Observatory. And maybe I'd rather not start on that.
At least for this session. Maybe in the future, when we have further time to talk about it, we could talk about that?
OK. Maybe we can leave it at that for now. But I have two things that I didn't want to forget, from an early period that I missed, at least two things. The first was, taking them in chronological order, between 1947 and 1951, you were on the ApJ board. And this is of course while you were at Washburn, and the other members, a number of them, included Mayall and Morgan, who was also one of the editors, Spitzer, Russell, Baade, O. C. Wilson — what kinds pf policies were there?
I don't think that we ever met.
You never met once? It wasn't the policy to meet, or what?
Chandra (Chandrasekhar) ran it, pretty much.
Then you were one of the closest of the editorial board, physically, to Chandra, along with Morgan. Did you have any contact with him on JOURNAL matters at all? What did it mean to be on the board, at that time?
Oh, I think you perhaps got certain kinds of papers to referee. But not very much else.
How did you feel about that?
Oh, I didn’t feel slighted.
How do you feel about it today? Has it changed very much?
Well, when I retired, I resolved that I wasn't going to meddle in things that younger people had the responsibility for, and in general, I've lived up to that promise to myself and others.
In dealing with that time, then, when you were on the board did everyone accept the way Chandra was running the ApJ?
I'm sure there were differences of opinion. But he was a very forceful character. No one ever impugned his motives or his integrity - never even close to that. I guess people thought that he had some things that he felt too strongly about, and other things he didn't feel strongly about. I think I agreed with what was said when he finally retired - that it was always a good journal, ever since J. Keeler and Hale founded it, but lifting it to world status was the single-handed work of Chandra.
That's a very interesting thing to say. I think I've heard things like that before, but is that general knowledge? Or is that your opinion, or what?
That's my opinion. It wasn't mine alone. I don't know who else to attribute it to.
So there were no momentous decisions or referee policies or anything that have changed during that period? OK. Were there any papers· that were passed without refereeing?
Well, all I can reflect is something I go as an aside. Because Hale was one of the founders of the JOURNAL, it was sort of a house organ for Mt. Wilson and later Palomar papers. And there was a local editor. For a long time it was Frederick Seares. Then it was Paul Merrill, at Mt. Wilson. When I first went there, Frederick Seares was still around. And he was more or less of a martine about certain matters of style and vivid usage — you couldn't say "due to," you had to say "owing to" — and I think he was right. But the net result is that some of the members of the staff chafed under the rewrites that Frederick Seares did— they felt he wasn't letting them say what they wanted to say. Baade was one of them. When Bowen reorganized things considerably, in the light of the financial problems that came upon the Carnegie Institution after the war (such as rising costs) that was one of the things that was changed. One change was not sending these contributions automatically to all and sundry all over the world; you had to ask for them, you had to ask for reprints. And he instituted, perhaps in consultation with Chandra, the custom that any staff member could send in his own papers without putting them through a local editor, and that they would be referred in the came way as everybody else's. The previous policy had been that if the editor of the Mt. Wilson contributions said, "This has been reviewed and approved," — it was assumed that it need not be refereed any more. Bowen chuckled about the fact that the first three papers that were sent under the new policy bounced. (Laughter) Obviously he was right.
Who was the editor?
Chandra. He certainly did referee some of them himself, if they were in fields he was specially concerned with. He knew an awful lot about everything, however. But I'm sure he did send others out. I have no way of knowing whether refereeing either internally or externally was the universal practice. I would put money on the probability that observational papers that did not involve the Bind of theory that Chandra was interested in were reviewed externally.
Were the feelings between Harvard and Mt. Wilson still pretty sharp, at that time, or had they mellowed quite a bit? With Greenstein going to Yerkes to Caltech?
Oh, I think they had. There was a growing catholicity of interests in Pasadena, with the starting of the astrophysics department at Cal Tech, and the rise in interest in astrophysics among the Cal Tech physicists. W. Fowler would be one of the first. There were others, like Leverett Davis and Bob Christie.
OK. One final thing. In 1953 you worked with Morgan and Code on the spiral structure of the galaxy, especially the inner arm, and I'm interested in how that cooperation came about. Code was at Washburn at the time?
That's right. That's right. There was a very warm feeling between W. W. Morgan and A.D. Code, and me too. Code had done his graduate work at Yerkes, and had sat under Morgan as a spectrum classifier, and was good member of the class — "had a good eye", as Morgan would say. And the general picture of the spiral arms as outlined by the H II regions, and the O-B associations, was just germinating. I think it was Morgan, Osterbrock and Sharpless that published the seminal paper on that. I remember seeing a model in Morgan's office, before it was published. (1952 Sky & Tel 11, 138)
This was right at that time?
Yes. Morgan had talked to Code and me about collaborating on some photometry and classification. The photometry that Code and I contributed were part of what Morgan needed to confirm the hypothesis that most OB stars lie along spiral arms. He did the lion’s share of the work in putting it all together. Code's spectra and photometer of southern hemisphere stars were of some help. Morgan's hope that these two numbered papers of a sequence would be continued in a long period of collaboration wasn't realized. We let him down. We didn't do any more. Other things must have seemed more important at the time.
Had you known about Dort's work, on the 2l-cm lines of hydrogen at that time?
Yes, I think so. I don't think I knew about it prior to publication — either we weren't on the circuit, or there wasn't this voluminous circulation of preprints which is now the standard method of getting the word out, before the slow journals.
But was there any sense of a race, to be the first to determine spiral structure, between the radio people and the optical people? I was wondering why it took until the early fifties and sixties to really put luminosity criteria to work.
What was the date of this paper?
The 2l-centimeter line had been discovered, but it wasn't yet very much exploited.
Right, but Oort's work from the Leiden group came at exactly the same time as the optical work of Morgan, Osterbrock, Sharpless, and also your work with Code and Morgan. All this appeared within a year's span of time.
I don't think there was a race. I think we were wrestling with a longstanding problem, that the pitch angle of the spiral arms is quite different by radio methods than by any optical model that could be gotten up. This was realized from the first, I remember.
But that was sort of a blend, of the Perseus arm and the Orion arm?
Well, the most principal squabble was about the Cygnus Arm, as I remember it. I'm afraid I can't comment any more about it than that. I don't remember that there was any rivalry or race. It was a case of each was hoeing his own row as best he could, and being interested in what the other people found.
OK. That's good to know. That keeps historians from going around looking for things that don't exist.
Well, I must put in a caveat. There are things that I don't remember as having positively happened. But that doesn't prove that they didn't happen. It just proves that I don't remember it now.
I'm most interested, of course, in your own association, how you felt about the developing picture of galactic structure at that time. Also the future of the Morgan-Keenan system of classification, and all that development implied for techniques of photometry, intermediate photometry, how these were aiding classification?
I was a spectator, for most of that. I joined in the general high regard that most people had for Morgan's way of sorting them out. Over the years, more and more people have gone to band indices of various kinds, to try to sort out the properties of stars, including a third coordinate, metal content. But there are a few — well, Bob Garrison's been on it for a long time. He's a Morgan disciple, now at Toronto. There are things that you can do very well with the Morgan classification system, just by eyeballing the spectra.
Line ratios, and spectroscopic criteria. OK, well, we've covered certainly an awful lot of ground, in this session. I certainly want to be able to meet with you again some time in the future. So, tentatively at least, for the rest of the transcript, as I understand it, we will pick up another session, another interview session, some time in the future, starting with your Lick years, and the conclusion of the l20-inch telescope and the development of instrumentation here; also, the origins and organizations of what has come to be known as the WHITFORD REPORT, on the future of astronomy. We'd be very interested to know how the various meetings went, and how reports given by the committee were balanced between observational astronomers, theoretical people interested in space and so on and so forth — and continue on in this vein. Is this how you would see it, also, a continuation?
I'd be glad to do that.
OK, fine. Is there anything we've missed or any comments you feel you should add at this time?
Oh, I don't think so.
OK. Thank you very much for your time.
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