Nicholas Mayall

Hetherington:

This is Norriss Hetherington, interviewing Nicholas Mayall, in Tucson, Arizona. Can we start with a general question, when and where you were born, brothers and sisters?

Mayall:

Sure. That would be fairly easy to do. I was born in Moline, Illinois, May 9, 1906. I have one brother, Edwin, living, who is 14 months younger than I am. He is a lawyer, and lives in Stockton, California.

Hetherington:

What did your father do in Illinois? [Mother's educational background? Grade and high school?]

Mayall:

My father was a five-year graduate in mechanical engineering from the University of Illinois, and he is now deceased.

Hetherington:

So you already had some university background in your family, and in science, too.

Mayall:

More or less in engineering. I thought that I would enter engineering, as I had my father's example, and I thought that I wanted to go into some type of engineering. When it came to a decision, after I'd done my freshman year,

Hetherington:

— where was that?

Mayall:

At Berkeley, University of California.

Hetherington:

Why did you decide to go to Berkeley?

Mayall:

My family lived in Stockton, California

Hetherington:

Oh, you'd moved? [Father moved from Illinois for a new job? Yes.]

Mayall:

There was a separation in our family. My father stayed on in Stockton. My mother, my brother and I moved to Berkeley when we started in the university.

Hetherington:

What year was that? [Move in order to attend university? Yes.]

Mayall:

We went there in 1924, and I entered the College of Mining, because I found by looking at the catalogue curricula that there were more electives offered in the junior and senior years than in any of the other engineering schools. I enrolled in the College of Mining Engineering in August, 1924, with very little idea at that time that I would become an astronomer, although I was much interested in it as an avocation. I had read all the books I could find in the Stockton Public Library, and had had some encouragement to study further from my physics teacher in Stockton High School. He was quite a remarkable man, one of the best teachers I had in my career, and I think he —

Hetherington:

Who was he?

Mayall:

He was named J. C. Corbett. He taught physics at Stockton High School, and I was his lab assistant. I learned how to operate all the laboratory instrumentation that we had.

Hetherington:

Did they have a telescope or anything of that sort? (crosstalk)

Mayall:

Oh, no astronomy was involved, but as I remember, this was the earliest days of radio, and he had stretched a wire from one end of this long building to the other, about 1500 feet. He invited me up to the lab one evening, and he hooked up one of these “cat whisker” detectors. We twiddled around the cat whisker on the crystal until we heard a radio station for the first time in my life! That was a big thing in those days, those cat whisker detectors. Well, my job was to set up the instruments for him, the ones used in the lab experiments, and I got the magnificent sum of $5 a month. This I would save up, two or three months at a time, in order to buy my tennis gear, because I was an enthusiastic tennis player, and about every two or three months I'd need a new racket or a new pair of shoes or something — I saved up that money so I could play tennis.

Hetherington:

Then you entered Berkeley in '24.

Mayall:

I entered U.C. Berkeley in 1924, in the School of Mining Engineering, with no thought of an astronomical career, although I had read fairly widely, including Young's ASTRONOMY, which was a very famous textbook.

Hetherington:

This is C. A. Young of Princeton?

Mayall:

C. A. Young — yes. I read that from cover to cover, but I was interested in it as an avocation only, at that time. Well, I started in, at the mining school, and everything went OK until the second semester, when I had to take a course in mineralogy. Also, chemistry began to get a little bit complicated, when I found out that I could not tell the color changes in bead tests in mineralogy, or in titration in chemistry, or in flame tests even, in physics. I have a color deficiency. I'm not color-blind, but I have a color deficiency that prevents my distinguishing purple from blue, brown from green —

Hetherington:

The flame test is what you use commonly to identify minerals —

Mayall:

— Oh yes, and the bead test too. And titration, of course, in other fields. So, midterm exam time came. I took it and I got the lowest grade in the class, which was a stunning blow to me, since I knew that the Dean of the college would get this notice. I sought an interview with him. He had received the information and he wanted to know what the score was. I said that I was having problems because I simply couldn't discriminate these colors in these vital tests, and right away — he was Dean Probert — he said, “You have no business being in mining engineering!" This was toward the end of the second semester, and he said, “I will authorize your dropping that course, and I recommend that you finish the semester, and then change your major.” He said, “I’ll see to it that there's no red tape in your way, you won't have to pay any fines or fees, as a result of this change..."

Hetherington:

It sounds very nice of him. Were your other grades OK?

Mayall:

Well, they were adequate, but not outstanding. I could have stayed on, though, if I wished, probably without being a very good mining engineer. The semester ended and I passed all my courses. And then, during the summer, I had to work at the Main Library in order to get enough money to return to school.

Hetherington:

Did school cost a lot then?

Mayall:

No. Fortunately, it was fairly cheap. But also jobs were hard to get and they paid very little. The job I got at the library was paging books at 35 cents an hour.

Hetherington:

Berkeley had just the incidental fee but not the tuition?

Mayall:

They had what they called an incidental fee, and I think it was $25 a semester or something like that. But in engineering there were lab fees that ran to much more than that. However, I had already decided to transfer to the College of Letters and Sciences, but I didn't know what department I would be in.

Hetherington:

Something in science?

Mayall:

Well, with the family financial resources at about as low an ebb as you can imagine, it was very uncertain whether I'd be able to return, because I had to earn enough money in the summer to come back. Fortunately, I got this job at the University Library, and I worked about 60 hours a week. My mother was keeping house in a small apartment for herself and for my brother and me, and so our living expenses were quite reasonable, as long as both of us worked, and she had a small stipend that she got from her mother.

Hetherington:

You were living in Berkeley. I suppose that helped?

Mayall:

We were living in Berkeley, yes. I toyed with the idea for some time of maybe going into some business administration or something, in which I might become better acquainted with money, and perhaps make some more. I was uncertain — I had thought of astronomy, but not very seriously. I discussed this situation with my mother, who was not a college graduate, but she was the one who said I should go into that field in which I was interested, but if I did, she expected me to do well. She backed me up, urging me to make my own decisions. I was then inclined to check out a business curriculum I looked over the courses in the College of Business Administration, or something like that. They were the dullest set of courses I could ever imagine. I didn't think I could stick it out. So I said to my mother, "Well, I think I'll find out what the prospects are in astronomy as a career." I called up the Astronomy Department one morning, and asked to speak to an astronomy professor. I got one who happened to be there teaching during the summer session. He was Dr. William F. Myer — “Bill" Myer, a very fine teacher and a very understanding guy, and I asked him a lot of very impertinent questions. In the first place, I told him what my situation was, and I said, “Can I earn my living in the field of astronomy? “ He said, “Yeah, if you‘re good enough.” I said, “Well, do you have any regrets that you yourself entered the field?” He said, “0h no, I’m very happy. I’ m very glad to encourage you to do it, if you're willing to work hard and never expect to make any fortune.” I said, “Well, that wasn't on my mind. All I am interested in is continuing my education and coming out with something on which I can earn a reasonable living... I did not want to make a great fortune or anything of that kind. He then questioned me how my interest arose in astronomy. I told him the books I had read, among them Young. He said, “Oh, you can enter the department here, without having to take any of the elementary courses.” That remark encouraged me somewhat, so I said, “Is there any prospect of getting a job there?” He said, “Well, you have to prove yourself before you become eligible for any kind of a fellowship, or any other kind of support. We have to see what kind of a guy you are, and how you do.” I said, “Well, if I make the switch, I will, of course, try hard. But I don't want to do it if you think the field is too crowded, or if you think that the jobs won't be there even if I do finish with a good record.” He said, “No, I don't feel that way about it. At the present time, there's more demand for astronomers than there are astronomers. You may have to go to a small college to start, but then, if you still continue your interest, and want to become a staff member in an observatory, you can keep your sights on that as a goal and try to reach it, stepping up from teaching.”

Hetherington:

That's interesting, how the teaching and the staff work at the observatory is rated — I guess it still is.

Mayall:

Oh, yes. It was a vital part of any of the astronomical graduate schools that I know anything about. Teaching is really a big thing, but, of course, research is too.

Hetherington:

You were thinking of going on to graduate school already, or was this just going to be the four years with the B.A.?

Mayall:

I asked him that question. I asked him what higher degrees you had to have. And he said, “Well, if you want to go all the way, if you want to qualify for either an academic position such as a professor on a faculty, or a staff position in a major observatory, you've got to have a Ph.D.” I said, “Well, do you have to have a Master's in addition?” He said, “No. You have to have only the higher degree, and if you can get it — and your record shows that you have a good chance of getting it — we do not advocate you’re getting a Master's.

Hetherington:

Did they find support for you, after you'd been in the department?

Mayall:

Yes. After I'd been about two years in the Department of Astronomy, Professor A. O. Leuschner, who was the head of the department at that time — (crosstalk) —

Hetherington:

The Leuschner Observatory?

Mayall:

Yes, it was named after him, in later years — he had a grant for working up all the orbital material on the minor planets. Berkeley at that time was known as an orbit-computing bureau for the minor planets and comets. You perhaps know that. Everybody who went there had to learn how to calculate orbits.

Hetherington:

I did too, but not very well at the time I went there.

Mayall:

It was one of the best trainings I've ever had in numerical calculation, and I never regretted it. But I'm glad I didn't stay in celestial mechanics, because I became so much interested in astronomical instruments.

Hetherington:

That field sort of dried up, really, hasn't it — celestial mechanics?

Mayall:

It's come on, in different ways. Yesterday I was just talking with a Greek professor of theoretical celestial mechanics in the University of Athens, and it's really being vitalized, in the sense of being applied now to stellar dynamics and galaxy dynamics. It represents a refinement and a ramification from planetary mechanics to galactic and inter-galactic mechanics, and it's a very live, active field at present.

Hetherington:

Did Berkeley do much teaching of, say, astrophysics at this time?

Mayall:

No. It was a minor part of the curriculum, but they had some very good men. The best known, of course, was Dr. C. Donald Shane. He was my first professor there in astrophysics. He taught a crackerjack of a course in introductory astrophysics, and later he taught a course in statistical mechanics. I don't remember what exactly the course was called, but he was a key man in the astrophysical curriculum. It was a minor one compared to the field of celestial mechanics applied to the solar system, particularly the minor planets and comets.

Hetherington:

Because of Leuschner's interest?

Mayall:

That was what the whole department was; he built it around that field in which he became probably one of the foremost workers, and authorities, in the field.

Hetherington:

What was Professor Shane doing, something like spectroscopy?

Mayall:

He was interested in solar spectroscopy. He set up a spectroscopic lab there, with a small heliostat, to work on the solar spectrum, using interferometry methods, which in those days were on the same par as you might say electron image tubes are now. Those methods were almost unknown amongst astronomers. And he had gotten that technology from his association with other astronomers, particularly ones in Pasadena, with the solar telescopes down there on Mt. Wilson. He had gone there to work with them. It kindled his interest enough that he came back and set up a small solar lab at Berkeley. That's where I became acquainted with him.

Hetherington:

So the students did get to participate in the faculty research?

Mayall:

Oh yes, very much so.

Hetherington:

I don't think undergraduates really get that much opportunity anymore. I’m not sure.

Mayall:

No. They were exposed to being roped in on the calculation of a comet's orbit, as check computers, something like that. I did computing on orbital elements before I even entered graduate school, because Leuschner hired me on his minor planet program. I got very well acquainted with minor planet statistics and orbital parameters, methods of getting definitive orbits and osculating elements, perturbations, and all that sort of thing, long before I became a graduate student and took those courses at the graduate level. I was lucky in that respect. So during my senior year and my first graduate year, I worked on that program with Leuschner. The man that actually ran it under Leuschner's supervision was Holger Thiele. He was not a Native American — I forget from what country he came. He was a whiz at that sort of thing and Leuschner got him there to run this program.

Hetherington:

There were just a few professors, then? About how many students would you guess were there in your day?

Mayall:

Less than a dozen and, most of the time, I’d say of the order of six or seven.

Hetherington:

Did they go on to have good careers afterwards?

Mayall:

Most of them did, but not all of them. One of my classmates, when I entered there, was Fred Whipple. He and I, as classmates calculated orbits of several comets. He stayed in that field as you know, but I didn’t stay in that very long.

Hetherington:

When did you switch out of it? When you started working with Shane as an undergraduate?

Mayall:

I started working with him because I was completely unexposed to that type of astronomy. He sharpened my interest in it. But the real break for me came during the summer session of, let’s see, when was this? I had completed my sophomore year there, which would have made it 1926. They had a summer session, and they invited Seth B. Nicholson from the Mount Wilson Observatory to come up and teach a summer session course. When he came, I was working around there, doing various odd jobs. Leuschner was very kind; he hired me to look after his own personal library, and also I got involved in the departmental library, because I had had two years Main Library experience.

Hetherington:

Leuschner was helping out with his own personal funds as well as university funds?

Mayall:

Yes, he employed me quite a bit on his personal things. And then he paid me for extra library work, because at that time the department was given the entire ASP^[1] library. It was just a bunch of books in a room there, and he had me organize that, and get it filed in shelving so it was available as part of the departmental library. I did that also during the following semester. But what happened, the real break, as I said, was when Nicholson came up to teach this summer session course, because he wanted somebody to read exams and papers for him, and to help him with the night time class experiments.

Hetherington:

To read student papers? Grading?

Mayall:

Yes. To do the paperwork follow-up in connection with the course, while he prepared the lectures and gave them. I would be responsible for all the paperwork that the students turned in, and helping him at night, because he had some night experiments. That was one of the most fruitful contacts I ever made. Seth B. Nicholson, although he was at that time a senior member of the solar department or solar group at the Mount Wilson Observatory, was really a very broad gauge astronomer, which few people recognized. His interests really ranged over the whole field of astronomy, although he was consciously tied to specializing in solar astronomy. I learned a heck of a lot from him. He asked me if I ever thought of working in an observatory. I said, "Sure, but I have to finish my degree work." He suggested, "Well, I know there's going to be a vacancy on the computer staff at Mount Wilson next year, beginning January one. Would you be interested?” I said yes, provided I didn't have to come before I finished the academic year. So he said, "I'll see what I can do for you. We don't have any applicants, and it's a kind of a routine job. You just help make reductions of observations for the astronomers." And he didn't know with who it would be. So I said, “Sure, I'm interested, provided I don't have to interrupt my academic year. I'd be willing to come down next summer and maybe stay on a year or two." By that time, I was getting pretty fed up with academia, after five years of courses. Nicholson went back to Mt. Wilson Observatory and reported to Dr. W. S. Adams, who was then the director, that I was interested in the job, but would like to come there following the academic year. Dr. Adams said they could get along all right, since they hadn't any applicants, and they didn't really need anybody until the end of the academic year, why, I could come. But he made no full commitment. He said in effect, “You go and finish your academic year, and if we have a job for you — if that vacancy is still there — then you can come down and have it.” Well, that's what happened. That experience really opened my eyes to the astronomical world. Those were the best two years of my whole career, as I look back on it.

Hetherington:

Sounds like a good thing, to have brought someone up to Berkeley for the summer. Did they do that frequently?

Mayall:

Yes, they did it as a regular thing. Usually they had one of the faculties there stay, but then they would invite in one or more visitors, depending upon available funding, but they made it a point of bringing somebody in. And that was the big break for me. And I'm sure it was for other students, too.

Hetherington:

He was able to do experiments there during the summer?

Mayall:

No, he was teaching. That was a teaching job.

Hetherington:

But you were doing something with him on night experiments?

Mayall:

Not in the way of research, no, because I was still working for Leuschner full time, on the minor planets. I had my finger in a lot of pies: minor planets, ASP^[2] library, Leuschner's library, and reading for Nicholson — I did all those things, more or less simultaneously and also looked after all the clocks.

Hetherington:

Well, on to Mount Wilson; I interrupted you.

Mayall:

I arrived in Mount Wilson in the early summer of 1929.

Hetherington:

1929, the year after you graduated?

Mayall:

Let's see, I graduated — I matriculated in 1928, I stayed for my first graduate year, which took me to '29, so I went down there in the summer of 1929. My first job there was to work with the spectroscopic group, which included Drs. A. H. Joy, R. F. Sanford, P. W. Merrill, Gustav Stromberg, and W. S. Adams, the director. I served as a computer for their spectroscopic plate measurement and reduction, and did a lot of work for Joy particularly. I worked up most of the material that resulted in a publication on radio velocities of the classical Cepheid’s in the galaxy.^[3] It's now a very famous classical paper. I did much of the reduction, while he did most of the plate measurement, although I measured some of them, just to get acquainted with the work. But I did most of the reductions of these measures that he made — hundreds of them. About that time, Dr. Adams and Ted Dunham were beginning their high-dispersion work — Dunham was installing the Conde spectrograph at the Conde focus of the 100-inch [telescope], and beginning to get the first conde spectra, of very high dispersion for those days, along with Dr. Adams, who had initiated the program. Thus I measured some of the very first Conde spectrograms for Adams, and to some extent, for Dunham, although Dunham was mainly interested in the instrument. He would take a few plates to sharpen it up, and then he would go on to other optical instrumentation. Dr. Adams was mainly interested in using it for astronomical problems. And some of the most fascinating spectra I ever worked on were those early Conde spectrograms of high dispersion.

Hetherington:

That must have been pretty exciting.

Mayall:

Oh, it was a revolutionary development at the time. Of course, it resulted in enormous advances in that field of high dispersion stellar spectroscopy. Ted Dunham, of course, found those faint molecular inter-stellar lines. He pioneered — he was the first discoverer of those inter-stellar molecular lines. They're very sharp and very narrow, and hadn't been found until he built this Conde spectrograph, and found them on his spectrograms. So he became interested in and specialized in that part of the field, whereas Adams worked pretty much on just stellar spectra. Also, in 1930, Pluto was discovered. I had had considerable experience at Berkeley in working on orbits, and Seth Nicholson knew me, and I happened to be on Mount Wilson at the time that the announcement came. I was working with the 60-inch telescope, and Adams had received a notice of the discovery from Flagstaff.^[4] Since the 100-inch was on a several-nights long exposure, he asked me if I would take the first photographs of Pluto with the 60-inch, which I did. And that got me interested in Pluto. I came down to Pasadena, Nicholson and everybody else were wondering what kind of orbit it had. Although the first orbit had been published shortly thereafter by John Miller, at Lowell Observatory, it had a high eccentricity and we didn't believe it. None of us believed it was right, because it had been based on too short an arc, and we also suspected there was something wrong with the earliest discovery observation.

Hetherington:

Because of the eccentricity that they calculated?

Mayall:

They were way off on the eccentricity because they didn't have a long enough arc, and because some observations, especially the first observations at Lowell had some errors in them. We tried to fit orbits to them. I should have prefaced my remarks by saying that Nicholson invited me to work with him as a check computer. And I really found out how to compute orbits under Seth B. Nicholson. He was a genius in celestial mechanics, which is not generally known, and he had developed methods to follow the fainter satellites of Jupiter, many of which he discovered, and he had that thing right on his fingertips. Doing an orbit on Pluto was just like falling off a log, compared to comet orbits. Also, for the first time, I gave up log books and used an electric calculating machine, which was a great, new thing in those days. Of course, it isn’t now, it’s almost never used, but in those days, they were just coming on the scene.

Hetherington:

— for stellar interiors, a little later?

Mayall:

Yes, they were being used for stellar interiors, structure, and so on. But I used a computing machine, a brand new electric machine, working with Nicholson on the orbit of Pluto. And it was a fascinating experience, because not only he and I made the current observations with the 60-inch, but we had a good set of earlier ones. He knew about them because he was there, at Mt. Wilson, when the pre-discovery plates were taken in 1919. Anyway, there were some pre-discovery plates on file there, taken with the 10-inch Cooke triplet, and he knew that they covered the orbit of Pluto. And so we spent — since we had a preliminary orbit, a good enough orbit — a lot of time fitting all the modern data to project it back to the dates when these plates were taken — Oh, my memory of dates fails me. I ought to know, because I looked at those plates for hours and hours. I think it was in 1920, or earlier.

Hetherington:

Well, we can check it. [later; date of plates meas.: Dec. 1919, see p. 19, 3rd line from bottom]

Mayall:

Yes, you can check those dates, because it's in the publication that resulted from there on "The Positions, Orbit and Mass of Pluto" by Nicholson and me.^[5] It's all Nicholson, so far as I'm concerned. He was very kind to let me in on that joint authorship. But anyway, what I wanted to say about that work is that nobody knows how difficult it was to spot those images on those pre-discovery plates because, at the time they were taken, Pluto was in the middle of the Milky Way, and you can imagine what a two-hour exposure, with a 10 inch-F 4.5 lens, shows you in the way of faint stars. It just looks like — like a sandy beach, you know. It goes down to a faint limiting magnitude where the stars are just not really resolved. And, of course, we had a friendly rivalry going on there. I set up a pair of plates, and he set up a pair of plates, and we drew the line of the orbit. We narrowed it down to, oh, within a few centimeters on the plates. I spent one whole weekend, beginning Friday, and extending through Saturday and Sunday, looking at this area of a few square centimeters — blinking it and looking at, oh, jillions of those stars, and I couldn't find a damn thing.

Hetherington:

Trying to find a spot moving —

Mayall:

I tried to find an image on one that would hop to an image on the other, and I saw no such thing in that area. Well, Monday morning came around and Nicholson said to me, "Well, what luck did you have?" I said, “I burned my eyes out and I simply didn't see anything... He said, “I think I got it.” Well! I was astonished. I said, “I've got to see this. I thought I looked at this field pretty carefully, and I didn't see anything.” He said, “Come on over, I'll set it up for you.” So he adjusted the blink microscope and said, "Now, I'm going to put the position very close to the intersection of the crosswire, and if you look at one plate, and then you look at the other, you'll see it." I looked and looked. I moved the plates around a little bit, but I still couldn't see it. Then he drew me a picture of this very small area. He said, "Now, I'm going to put the intersection across, right smack on, the first image. Then you'll see the second one." Well, the first one, which he said was the first image, was two stars so close together they were almost amalgamated. It was an extremely close pair of stars, and there were jillions of things like that. Then I said, "Now I want to see it on the other plate." So he said, "OK, I'll put it there. Do you see something funny?" I said, "I see a pear-shaped object." He said, “Yes, that's the second image." Then I realized that the planet had moved so close to this other star that it was no longer separated from it. So here was a very close double star on one plate, and a pear-shaped image on the other plate, and Nicholson found them! We measured them up, and they were really the breakthrough, on getting the accurate orbit for that planet. Then some other earlier observations by others came along. We used those also, but we found errors in some of them that later were confirmed. So we were able to reject some of them, and to keep only the really good observations, and that's how we came out with the first reliable orbit." Fred Whipple and another fellow [Bower] had been working on it, but they didn't have the benefit of some of the knowledge of Nicholson. They were using other observations some of which were faulty. However, we published the 10-inch observations individually before we had the orbit — we got them out just as soon as we could.

Hetherington:

Were things published pretty quickly?

Mayall:

Oh, yes, as soon as we could get the plates measured and reduced, the results were published. They appeared on a Harvard announcement card,^[6] although we didn't have the orbit at that time. And we weren't going to publish that orbit until we were sure. Fortunately, we had a long enough arc that eliminated all the bum observations. It was extraordinary, the errors that were made in some of those positions published by other observers.

Hetherington:

Just in the positions?

Mayall:

Yes, just errors in calculation or measurement or both. And you really had to be on your toes, and enormously experienced, to spot those, and that's where Nicholson came in. He was way ahead of the rest, in sniffing out observations that had errors in them.

Hetherington:

Do you think these were sorts of errors that probably came in the reductions?

Mayall:

Could be. We never knew, of course, but we would become suspicious of these things. We didn't come out in print with them, but Nicholson would write to these people to say, "I think your observation is in error." Then they could remeasure them, and by God, every time, they were corrected.

Hetherington:

Once he had his rough orbit, he could tell what positions was way off?

Mayall:

Yes. Getting this orbit was a very, very, and fascinating business. We finally got an orbit, where we could fit all the observations that we felt were reliable, going all the way back to 1914 — an observation published by Max Wolf, obtained with a very short focus camera.^[7]

Hetherington:

He was at Heidelberg?

Mayall:

Yes, at Heidelberg. That position was OK. So we had an arc from 1914 to 1931, or something like plate '30. And that was sufficient to really pin down the eccentricity. So then the question was, how should we publish this orbit? Should we publish an osculating orbit, or should we go a little bit farther and publish one that included perturbations of the major planets? Because, you see, Percival Lowell had predicted a number of places, or a number of positions for this planet, but the trouble is he'd made the mistake of predicting too many. It turned out that the best one was within a degree, but nobody knew at the time which was the best one. Anyway, we felt that we should find some way of including some of these perturbations, so that the orbit would last longer than an osculating orbit good just for one epoch. And also, it would be more reliable to go back still farther than 1914, if anybody wanted to look up other pre-discovery plates. Then Nicholson had what I considered to be a brilliant idea. We actually calculated some of the special perturbations and found out how they ran, but Nicholson said, “I think we can do better than this.” Of course, I hadn’t any idea what he had in mind. He said, “The run of these perturbations of the major planets suggests to me that if we refer the orbit not to the sun, but to the barycenter of the planetary system, which includes principally Jupiter and some of the other major planets and the sun, then we should be able to approximate these perturbations over a much longer interval of time, without calculating the special perturbations.”

Hetherington:

This is the gravitational center?

Mayall:

Yes. The barycenter is the gravitational center of the solar system, and it lies within, or very close to, the edge of the sun. Also, that position can be calculated with great accuracy, on, for centuries, millennia back and millennia forward. All you have to do - and you don’t have to compute special perturbations for it — is to make a coordinate transformation that includes the positions of the planets at any time you want an orbit. Then you calculate from the positions of the planets where the barycenter is, and refer the orbit to that position for the date of the osculating elements, for any particular year.

Hetherington:

Was this a new technique with Nicholson?

Mayall:

Yes. It had never been tried by anybody — so far as I knew. Well, when we referred those elements to the barycenter of the solar system, they were adopted and used for years in the AMERICAN EPHEMERIS AND NAUTICAL ALMANAC; for all I know they may still be using them, but they were used for, oh, 10 or 15 years at least. And they resulted in more discoveries of earlier pre-discovery plates, too — although that wasn’t so critical. But it meant that, if you had these barycentric elements, which we published, it’s a much simpler matter to get an ephemeris for any epoch before and after 1930, with high accuracy — positions accurate to the order of a few seconds of arc; and it’s just as good as calculating the special perturbations. Well, one thing I really learned was how competent Nicholson was in his field.

Hetherington:

He's not really thought of as working in this field?

Mayall:

Never mentioned at Berkeley. However, that was only one of the things I worked on at Mount Wilson, for I worked with a number of others there. Toward the end of my stay, I was asked by Humason^[8] to carry on and finish up his program for getting the spectra of stars in the Kapteyn Selected Areas, because he was at that time getting interested in measurement of red shifts of faint galaxies. Edwin Hubble, of course, was working up his red shift law, on the basis of a very small amount of data, principally Slipher's^[9] measurements, and a few by Humason. The big push was just beginning at that time to get fainter nebulae with larger red shifts. I was in on that program from the ground floor. That's the program that really determined my main career interest.

Hetherington:

The Mount Wilson system was that everyone lived off the mountain and you'd just go up for observations?

Mayall:

That's right. Well, I finished up this program for Humason. And then, about that time, Hubble was beginning to take plates for counting the galaxies, and so he asked me if I would like to work on that program. I said, by all means, I'd love to take these. So I took most of the 60-inch plates for him, some 100 of them. Hubble said he also wanted to have a set taken with the 10-inch Cooke lens, at a brighter magnitude limit, and so I took all those for him.

Hetherington:

At that same time, Humason was doing most of the spectroscopic work?

Mayall:

He was doing the spectroscopic work, right. So that's really how I got involved in the field that became my major research interest after I left Mt. Wilson. When I left, I had already selected a thesis subject with Hubble, which was acceptable to the people at Berkeley, so after two years in Pasadena I went back to Berkeley.

Hetherington:

This was?

Mayall:

Mid-1931.

Hetherington:

It must have been pretty exciting working with Hubble at this time.

Mayall:

Oh, you can't imagine how electric the atmosphere was down there in those two years. So many things were happening in astronomy and physics — they all came to focus at that time and place. There were some of the greatest minds in science in Pasadena at that time. Henry Norris Russell^[10] was there, working on the results from some of the high dispersion spectra of stars.

Hetherington:

Did he come for the summer or for the year?

Mayall:

He was a Research Associate of Carnegie.^[11] He spent some months out there. J. H. Jeans^[12] came there, because he was interested in cosmology. Millikan^[13] at Caltech, and he was just finding the cosmic rays. One of the things I greatly enjoyed was the debates that they had, one proposing an annihilation of matter origin for the cosmic rays, and the other a collisional process.

Hetherington:

This is Millikan and Jeans?

Mayall:

Millikan and Jeans — one preferred annihilation, and the other, what was it? Collisional action? — I can't remember. But anyway, they were completely opposite.

Hetherington:

Were there seminars, debates?

Mayall:

Yeah, there were — they would announce a sort of a general colloquium, you know. These two guys would get up. Each would present his side. Then there would be discussion, all at the library of the Mount Wilson Observatory. It was fantastic. The last year I was there, Einstein came, and he sat in an office right across from Hubble. I'd see him every time I walked down there. He was sitting there working, and there was a lady nearby making a sculpture of him. He was being sheltered, from the press, as much as they could, by the Observatory. They locked the doors and issued keys. It was really a terribly interesting thing.

Hetherington:

It was probably good for someone like Hubble to talk with Einstein about relativity theory?

Mayall:

Yes. Yes. Hubble was really a tremendous attraction, for many theoreticians.

Hetherington:

The theoreticians wanted his observations.

Mayall:

Yes. He was primarily an observer, of course, and I was working very closely with him.

Hetherington:

Although on quite a few of his observations he was having, say, you or Humason do them, wasn't he? Did he do any himself?

Mayall:

Well, we worked together. He did very little spectroscopy. I doubt if he took a half a dozen spectra. He spelled Humason a few times. But the fellow who produced most of those velocities and most of the spectrograms was Milton Humason. I got very well acquainted with him, because I used to go over to the 100-inch when he was on these long exposures, when I'd get a break in observing or if I was up there for some other reason and not actually observing. I'd go over and talk with him, sitting up there on the cassegrain platform by the hour. I was around especially when he developed the plates, and when he was getting set up on the faint nebulae. I saw what an expert observer he was. I don't think there was anybody around there who could have found these objects, even knowing where they were, of course, from direct photographs, and set them on the slit of an inefficient spectrograph, and with inefficient viewing optics. And he did that all the time in his career. The exposures, of course, were many nights long, and very few scientists had patience with things like that.

Hetherington:

He was getting to the really faint objects? Past Slipher’s objects?

Mayall:

Oh, yes. He was astounding people, to the point where astronomers like — well, I hate to mention a great name, but Shapley^[14] just didn't believe them. He said, “I don't believe these results,” when he came out there.

Hetherington:

A lot of people didn't believe Slipher's results at first, did they?

Mayall:

No, they didn't. They thought, well maybe his (Humason's) identifications of the lines were wrong. But they were wrong and he was right.

Hetherington:

Shapley came and visited him?

Mayall:

He came out there, and Humason was very, very open about everything. He wasn't trying to pull the wool over anybody's eyes. Quite the contrary. He would let anybody — he was ready to listen to anybody, if they had some ideas of what the features were. You could see the features, but sometimes they were very faint. However, he had the benefit of experience, of starting with lower red shifts, and then following them on the way out, as they got bigger and bigger. And that was an enormous advantage that other people didn't have. But when he improved his instrumental equipment with the Rayton lens, which really gave a very short spectrum, or compressed the spectrum, to show just the H and K lines and the G band. Then one could really see the H and K lines, and the G-band, and match them up with a star, and there was no question about identification. Although he'd been working with two or three times that dispersion, sometimes the H and K lines weren't of very good visibility, because the darned spectrograph screened out the ultraviolet light, — that's another story. But anyway, my experience with Humason at the 100-inch telescope was — as a friend and just an onlooker, really — had enormous influence on me. And also, working for Hubble, and seeing how careful he was, with his discussions of the observations — he was extremely restrained and conservative; he never used the word “radial velocity.”

Hetherington:

The “red shift?”

Mayall:

It was “red shift.” That's what you measure. He never went for the word “galaxy.”

Hetherington:

Possibly that was his legal training. I've always wondered if he was especially good at handling data because he…

Mayall:

I don’t know. He never used the term “galaxy,” to him…

Hetherington:

— extra galactic objects?

Mayall:

Extra galactic nebulae or simply nebulae — by implicit agreement nebulae were extragalactic to him. He wouldn't use the word “galaxies.” He preferred to use the word “Galaxy” for the Milky Way system, ''The Galaxy.” capitalized. He never deviated from that as long as he lived.

Hetherington:

Probably valuable to be that restrained, at this time, when these — all sorts of…

Mayall:

Oh, yes. They were having just a revolutionary impact on theoretical cosmology, because for the first time, such observations were really beginning to bring that whole speculative, metaphysical field down to earth, where you could talk about data and put numbers on them. Hubble was really, I think, the fellow who put cosmology' on an observational basis. Others had started it and tried it, but he was the one who really thoroughly established it, to where it became universally accepted. And it was because of his caution — he was a very modest man, and he was very careful, very restrained in his speech, very reserved in talking with others. And so, he didn't like anything flashy, anything flashy just turned him off, turned him away.

Hetherington:

But if you were doing good work, he was pretty easy to get along with?

Mayall:

If he thought that you had conscientious standards, weren't seeking publicity, etc., he'd do anything for you. He was a man of very noble character, I thought. I was fortunate. I was lucky to get associated with guys like that — like him, like Humason, like Nicholson, and others down there, too. Joy was a joy to work with. I got along with most of the people there, but there were a couple of characters I didn't particularly care about. But I got very much interested in the laboratory work that A. S. King was doing with exploding wires. That had a tremendous sequel to it during the Second World War I became interested in the rotating mirror and exploded-wire technology he was using to get spectra of ions of higher excitation, for classifying spectra according to temperature. He was doing that work at that same time, and I always used to go down to his lab, when I had time, and he would fire off some —

Hetherington:

— this would be over at the Caltech^[15] lab?

Mayall:

No, no. This was down in the basement where they had a physical laboratory at Santa Barbara Street in those days. A major physical laboratory there, which Hale^[16] had put in, mainly for solar work.

Hetherington:

This was at the same place the library is?

Mayall:

It was in the same —

Hetherington:

Santa Barbara Street?

Mayall:

Santa Barbara Street. It was a building to the east of the office building. I also worked with Merrill^[17] on his famous emission-line B-star program. I took many of these large plates, with objective prisms; the 10-inch Cooke telescope gave objective prism spectra, on 13 x 17 plates, of hundreds of stars, and he used these plates to find the B emission-line stars. And he found, of course, hundreds of them.

Hetherington:

There were still a few observations being made by van Maanen^[18] at this time. Did anyone pay much attention to him this late?

Mayall:

Oh, that's a whole different story. That's a very personal one; I was caught in it, as a middle man there. I was a young man, of course, and I made it a point to get along with both of them, [Hubble and van Maanen] but it was a difficult situation, and I — I didn't enjoy it.

Hetherington:

They didn't get along too well, I know, but Hubble, I think, restrained from publishing any criticism.

Mayall:

Well, he agreed to the Observatory's proposal, which was, eventually, to come out with two short papers.^[19] But there's much more behind it than that.

Hetherington:

Those were in the ASTROPHYSICAL JOURNAL, 1935, '36 —

Mayall:

Somewhere around there, yes. The only thing I ever heard him say, very, very positively, was, "My attitude on this subject is, no compromise, no compromise.” He was sure that he was right and van Maanen was wrong.

Hetherington:

I think he [Hubble] started re-measuring plates, I guess, just shortly after you left, probably, '31, '32.

Mayall:

That's an entirely different story. I was not involved in it, on the inside. I tried to keep it as peripheral as possible. By the time I left, I was making out the observing schedules for the 100-inch and the 60-inch, and that meant I had to shuttle between these two feuding people.

Hetherington:

Going and asking them when they wanted time?

Mayall:

Yes. They hardly spoke to each other. They'd pass each other in the hall, and neither would pay any attention to the other.

Hetherington:

But everybody else seems to have gotten along well? You had these seminars with good debates?

Mayall:

Oh, yes. And I must say that van Maanen was very friendly to me. He treated me like a, like a friend. He would invite me out to play tennis at the Valley Hunt Club he belonged to. He was quite a tennis player, but he was very helpful to young men who came there.

Hetherington:

I think he was helpful to a lot; I guess Lawrence Aller was one, from talks with him, among others.

Mayall:

Yes. That's one of the brighter parts of his life, how he was so helpful to young men there. He was not a teacher, he didn't teach formally, but he was helpful, in making them feel at home and getting along financially. And although I was working with Hubble and Humason, he didn’t criticize me for it, but was much more outspoken about Hubble and his work than vice versa. Well, I don’t want to…

Hetherington:

In ‘31 when Einstein came, do you think there was any major effect of Einstein on Hubble, or vice versa? What sort of results came from…

Mayall:

Well, that would be hard for me to say. Hubble actually worked closely with R. C. Tolman at Caltech. They were great friends, and they were admirers of each other’s work. Tolman was a relativist in his own right, you know. And I think it was Hubble’s...

Hetherington:

They had a joint paper in 1935?^[20]

Mayall:

Yes, they had more than one joint paper, and they were very, very close colleagues. They discussed many scientific problems together.

Hetherington:

There were meetings at Hubble’s house, too, weren’t there?

Mayall:

Oh, yes. A number of them.

Hetherington:

Did you get to any of those?

Mayall:

Oh, yes. Hubble was so nice. He would set these things up in advance, and he’d invite young people as well as his colleagues. I used to go down there, after 1931, while I was still working on my thesis — and also I had become engaged to my future wife then. We were married after I got my doctoral degree in 1934.

Hetherington:

She was in astronomy, too?

Mayall:

Oh, no. Since she lived in Los Angeles, I came down there to see her whenever I could, but always went to Pasadena where Hubble sometimes would ask me out to his home for breakfast, to have discussions with him, because I was working on a thesis subject that really came out of my association with him, on counting galaxies on all the old Crossley plates.^[21]

Hetherington:

This is when you went to Lick?

Mayall:

Yes, when I went up to Lick in 1932 to work on my Ph.D. thesis.

Hetherington:

What determined that you would go back there?

Mayall:

I wanted to finish up and get my degree, but I really wanted to stay on at Mount Wilson, because I thought this was where the action was. So —

Hetherington:

— Berkeley had the arrangement with Lick at this time, then, that graduate students go to Lick?

Mayall:

Oh, yes, from the very beginning with Lick Fellowships. The Lick staff and the Berkeley faculty were really part of the same department; although they were physically separate there was a close professional relationship. And at that time, in Pasadena, I had hoped oh yes, this is of course the time when the 200-inch project had started, and that was a big thing, too. I was involved in that only peripherally, but anyway — Also, the Caltech graduate astronomy department was being formed. It began the year after I left, and I debated whether I should hang around there, and wait a couple of years until it got established, or go back to Berkeley and finish up in two years. It was a tough decision for me, because my interest, potential colleagues and friends, were mainly down there, not back at Berkeley or at Lick.

Hetherington:

More exciting work was being done?

Mayall:

For me, yes. So, when I left, I wanted to know whether I had any prospects of getting a staff job there, if I got my degree at Berkeley. Well, some of my friends down there said, "We can’t say, or give you any firm commitment, but we sure want you down here. We’ll do everything we can to get you here, in two years’ time." Hubble, at that time, wanted to get an observing station in the Southern Hemisphere. His idea was to take the 60-inch to somewhere in the Southern Hemisphere, probably in South America. He didn’t know where at that time, and he said, “We have the money promised, but I don't know whether we can hold onto it for two years.” I said, “If you can, maybe I can go later?” He said, “I can't promise that, but if things work out, and we get the money for this project, I want you to go down with that telescope and to start work on nebulae in the Southern Hemisphere.” Oh, boy, that was the greatest thing on earth, for me! So I went away, hoping, if not expecting, to come back there after two years. Well, it didn't work out that way.

Hetherington:

Did Berkeley have financial support for graduate students?

Mayall:

Oh, yes. I got a Research Associateship, the Martin Kellogg Fellowship, which was the highest paying fellowship. They also had Lick Fellowships, two or three of them, that paid seven or eight hundred dollars, but the Martin Kellogg paid a thousand dollars — all per year. I thought that was great, because I could live on that — in fact, I saved money on it.

Hetherington:

You were living on the mountain, so…

Mayall:

Well, I also lived with my mother, too, when I was in Berkeley 1931-32. When I went back I finished up my course work in Berkeley, and then in ‘32 I went up to Lick, expecting to be there for a year or maybe a year and a half, but I stayed on.

Hetherington:

At this time you wanted to finish up quickly so you could get back to Mount Wilson?

Mayall:

That was the general idea, yes.

Hetherington:

I see.

Mayall:

But you know what happened in those years: there was a little thing called a Depression. Much of that money that Mt. Wilson had expected to get from the Caltech Associates vanished. Bankers, philanthropists, Associates of the Institute — their funds just dried up. And so, the 60-inch Southern Hemisphere project just evaporated. Nothing there. Also, the Observatory had to cut back on its programs during the Depression, because the Carnegie Institution’s income was affected. Thus they weren’t hiring new people at that time. There just was no opening for me when I got my degree in 1934. I can tell you that it was a cliffhanger situation at Lick, too. And right up to the time when I had finished — got my degree, published my thesis, got the parchment and everything — it came to a point where I was about to pack my bags and leave the mountain top, not knowing where I was going.

Hetherington:

I suppose the teaching jobs were drying up at this time?

Mayall:

Yes, the teaching jobs were drying up, too. I only had about a week left, when I had to make up my mind, and so I went in and had a heart to heart talk with the director, who was Dr. Robert G. Aitken. And he was a very kindly old man, but he wasn’t very knowledgeable in astrophysics, or especially galaxies. It didn't mean much to him what I wanted to do, but he realized my situation and said, "I don't have any jobs that I could offer you, but I do have some funds that have just recently become available. They're not enough for a regular appointment. It's the salary of an assistant janitor." I said, "Well, how much is it?" He said, "It's something like —" which I think was 12 or 15 hundred dollars per year. I said I was just about to be married, and he told me the job would provide a house rent free, but unfurnished. I jumped at it, saying, "I’ll take anything. What do I have to do?" He said, "You'll be assigned work, like looking after the clocks, making observations for other astronomers, and then, on your own time, you can do research with the Crossley and the other telescopes." I said, "That suits me fine."

Hetherington:

You had been working on the Crossley plates at this time for...

Mayall:

Yes, I had been counting them all for galaxies, and also taking plates for the same program, so I was well acquainted with the Crossley.

Hetherington:

The counts you were doing were very important to Hubble, weren't they, as sort of independent evidence to confirm the fact that —

Mayall:

— Yes, he was anxious to find another point on that curve, the number of nebulae as a function of limiting magnitude, around 19th magnitude or so, to fit in with his 60-inch and 100-inch plates it magnitudes 20 and 21.4; he wanted to see what I would wind up with. So I got that point on the curve from going over the old Crossley plates, taking new ones to fill in gaps, and then reducing them all to a homogeneous system, according to…

Hetherington:

There was some difference at this time between what was being done in the Western US and the East, wasn't there?

Mayall:

Oh, yes. Quite a bit.

Hetherington:

You had the big new telescopes in the West and more observations?

Mayall:

That's right. Yes, the real action in astronomy involving new instrumentation was in California, especially southern California. Although at that time the 200-inch was not yet in business, it had great potential. Mount Wilson was absolutely by itself —.

Hetherington:

— I wonder if Shapley regretted leaving Mount Wilson for Harvard?

Mayall:

Well, things were different when he left, of course, in 1921. He'd already been there a while and had made a tremendous contribution, in his work on the globular clusters. I think that's his best work, by far. It really showed, for the first time, where the sun's location is in the galaxy.

Hetherington:

Shapley sort of had the techniques to go on and do what Hubble did, didn't he, if he'd stayed? The Cepheid variables?

Mayall:

Yes, he might have. Of course, he did enter the field in different ways there at Harvard. He has many papers on galaxies, and he did find some interesting things, but I would say he didn't attack it on as comprehensive and fundamental a basis as Hubble and Humason did. He couldn’t, really, with the resources they had there. He could have — maybe pushed for time on the larger telescopes — but I guess he elected not to — maybe his responsibilities at Harvard were too heavy.

Mayall:

Perhaps I've been talking too much about myself, instead of on any questions you have?

Hetherington:

You've been covering the area that I was interested in. We might get into your work next. I suppose one of the first interesting things at Lick, once you had done the counts for Hubble, was the Crab Nebula work?

Mayall:

Oh, that was definitely a by-product, or fringe benefit. I always had a list of objects that I used as fill-ins maybe during a gap when the Milky Way was around, and I had to find objects to keep me going when the galaxies weren't around, especially in the summer time. So I had a list of these objects, all peculiar nebulae, and I just scratched them off, one after the other. I published notes on most of them, sometimes with their radial velocities. On one night I had worked up to within about two hours of dawn, and the next object on my list, this early morning, was the Crab Nebula. Well, I had never read up on the Crab Nebula, so I didn't know any of the background of it. However, I knew it was about the length of the slit, if I took off the little prism that put in the comparison light. So I took the spectrograph off the telescope, turned it upside down, and removed this little prism, so that I could get the full length of slit of 3/8 inch, or six minutes of arc, which is just about the length of the major axis of the Crab Nebula. Then I rotated the top of the telescope, so that the position angle of the slit would be along the major axis of the Crab Nebula. I had less than an hour and a half before dawn, so I'd have to push into dawn to get that much time. Anyway, I took this plate, although I couldn't get any comparison spectrum on it, because I'd taken the prism off. I developed the plate, along with others, the next day, and lo and behold, even in an hour and a half, I could see these long, bow-shaped lines, especially (?) 3727 of [OII]. This result excited me. I knew that the nebular spectrum had emission lines in it, and — that at some p1aces they were wide apart. However, it was the first time I had ever seen a spectrum of the whole nebula, showing this beautiful bowed structure, from one end of the nebula to the other, along the major axis. Later on that same day I went to the instrument shop to get the instrument maker to make me a little bar with two small holes near each end. I then had the bar soldered on the plate that carried that comparison prism. Next I determined how the assembly could be stopped, with the prism over the bar, to put comparison light in short sections at each end of this long slit. I got that all done by staying fairly late with the instrument maker. That same night, in the early morning, I then got a three-or four-hour exposure, with comparison spectrum, with the slit along the major axis. Either that night or the next one, I rotated the slit 90°, and got one along the minor axis. And then, of course, both plates showed the bowed lines, and not only 3727, which is the brightest one in the ordinary blue-violet spectrum, but others, such as the chief nebular lines of [OIII] and Balmer lines that really showed what the spectrum was like. I published those in a note.^[22] That's how I got into the Crab Nebula, and interested in the history of it.

Hetherington:

That struck me as interesting, being a historian of science.

Mayall:

Before I had taken these plates, I had really not read very much about the Crab. I knew Sanford^[23] had obtained some spectra, and I knew Slipher had some, but in their interpretations they hadn’t given any suggestions of an expanding gaseous shell from a nova that would explain the spectral features. That wasn’t mentioned by either one of them, but it was obvious to me once the spectrum of the entire nebula was obtained.

Hetherington:

You used Chinese observations at some point, didn’t you?

Mayall:

Yes, that is another interesting thing, but it’s such a long story and I don’t want to take up too much of your time. However, I really got interested in that as a bibliographical problem or program. I worked on that for years, and every now and then I still try to stimulate somebody to continue the search, because I’m sure there are other ancient observations. These Chinese observations that turned up were really confirmed — they were first mentioned in an article by Lundmark.^[24] Incidentally, Lundmark came to Lick when I was working on the Crab, and he was among those who stimulated my interest in the history of it. He was interested in old supernovae, and he had published papers on them. In one of these, he had noted the correspondence in position of the Crab Nebula, and one of these “guest” stars in the Chinese Chronicles, and then —

Hetherington:

Did he read Chinese?

Mayall:

No, he was not a Chinese scholar, but he knew Chinese scholars. So, one thing led to another, and I finally put it all together, for the first time, in an ASP leaflet,^[25] including a reference that Hubble had noticed the expansion rate. In essence, all these separate little observations are part of a puzzle that had never been put together. I think, without being immodest, that I was the first one to do that. Although when I published the spectra, it was, of course, plain to everybody that the Crab Nebula is an expanding envelope from a nova. But there was nothing unusual about that, for there are many galactic novae that have shown parts of this phenomenon, so the concept was not new. But in the case of the Crab Nebula, bringing these things all together for the first time, where I had the spectra of the object as a whole — I think that was my major contribution. But I did get interested in the ancient history of it, just as a fascinating sidelight.^[26] I have had lots of interesting correspondence, and have a fat folder, on it.

Hetherington:

You were also doing some interesting work on the direction of rotation of galaxies a little later.

Mayall:

Yes. That subject was something that interested me from the very beginning. As soon as I got a nebular spectrograph going with the Crossley, I felt like getting more information than just the red shift, which could very easily be done with the Crossley because of its smaller scale, or shorter focal length. Humason was handicapped because his equipment worked at the cassegrain focus of the 100-inch, which had big scale, and his spectrograph a short slit of about 10 seconds of arc. Thus he could cover on a relatively short part of a galaxy, whereas I had a slit usable up to six minutes of arc. And also, when it came to faint surface luminosities, like many galaxies, and especially their outer parts, I could beat the 100-inch every time, because my spectrograph involved only one reflection and had an ultraviolet-transparent, small prism system.

Hetherington:

This was with the Crossley?

Mayall:

Yes, with the Crossley and its smaller scale, and the single reflection from the mirror, I could get spectra covering a whole nebula in a fraction of the time that he could with three mirrors at the 100-inch cassegrain focus. On many of the galaxies that I observed, I put the slit along the major axis. This was not new, at all, but I was undertaking a major program to determine nebular red shifts. By agreement, Hubble, Humason, and I had separated the field. I was going to observe a certain category of them; they would work on the others. But I had many cases where such objects on that program would not make a full observing schedule, so I had to do other things. But at the time I did observe a galaxy, I always tried to put the slit Tong enough along the major axis, to detect any rotation. And I did that for many of them. And I also started out, along with Lawrence Aller on the gaseous nebulae in M-33, and then encouraged work, along with —

Hetherington:

He was at Lick at this time?

Mayall:

He came to Lick about that time as a student, before he went to Harvard.

Hetherington:

You must have had a lot of good Berkeley students up through there.

Mayall:

Oh my, innumerable ones. Speaking of rotation I had the idea that the Andromeda nebula should be worked on. Nobody had, up to that time, found any gaseous nebulae in it, but I was sure, from looking at only Crossley plates, that some of its non-stellar condensations must be gaseous nebulae. Hubble thought they were too, but he was too busy with cosmology to work on things like that. Thus I had every incentive to do it, and he encouraged me.

Hetherington:

You had the equipment.

Mayall:

I had the equipment that was especially good for faint objects of some surface brightness, you know, the kind that didn’t require a big scale and big aperture. A big aperture was no help, unless the object was semi-stellar. If it was a surface, I could compete, but if it was a stellar, oh, well, the 100-inch had it all over me.

Hetherington:

This is probably why Slipher was able to compete early, wasn't it?

Mayall:

Yes. So I had — I don’t know whether I had taken a few exploratory spectra, which showed, that some of these nebulous knots had bright lines, but that’s about the time when Horace Babcock^[27] turned up, and I recommended their observation for rotation as a thesis problem for him. And he did observe some of these. About this time, or somewhat later, Baade^[28] who had come to Mount Wilson the year I left, 1931, had started his color filler program, which identified all sorts of things in galaxies, among them these emission nebulae in M-31 and M-33. He subsequently found them by the hundreds. But at that time there was not a single gaseous nebula known in M-31. Horace Babcock made the first spectroscopic observations of them for radial velocity — except; I don’t know whether or not I made some exploratory observations. But I was absolutely convinced that the ones that I pointed out to him on Crossley plates would be gaseous nebulae, and every one of them turned out to be of that character. He measured their radial velocities and his thesis^[29] was the rotation of the Andromeda nebula based on those observations. Another thing I did — when he was exposing with the spectrograph, I was at the primary focus doing direct photography. He had brought down...

Hetherington:

— this was with the Crossley?

Mayall:

This was with the Crossley. He had brought down a small camera system that he planned to use to record the spectrum of the whole nebula on a smaller scale, attached to the lower end of the Crossley, pointing to M-31. Since I didn’t want to mix into that program, he fixed that up. His shorter focus camera lens projected a smaller image of the galaxy on the slit. He used the nebular prime focus spectrograph, without its support spider, strapped to the side of the telescope at the bottom of the telescope tube. This slit spectrograph was the same one that he and I had been using at the prime focus. Well, when he was working with this shorter focus camera on M-31, I borrowed a 6 l/2 x 8 l/2 inch plate holder from Hubble, and fixed up a wooden support spider for it and a cigar box borrowed from Doc Moore.^[30] With this larger plate holder from Hubble he said he could spare it for a while — I took some long-exposure direct photographs, with that haywire set-up. The photos eventually came out in the Lick Observatory Portfolio of Astronomic1 Photographs. But at this time, I wanted to get the whole of the Andromeda Nebula on the same plate. To get this nice big field I had to stop the mirror down to 24 inches, which meant the telescope worked at F/8.7 instead of F/5.8. While Horace was taking a long-exposure spectrogram down at the bottom of the Crossley with his short-focus imaging lens and getting a spectrum of the whole nebula from the slit length of 3/8 of an inch, I had the 6 1/2 x 8 1/2 plate holder up top taking a 4 1/2 hour direct photograph M-31 at the same time.

Hetherington:

That’s unusual to be getting...

Mayall:

We were killing two birds with one stone. It was a lot of fun. He’s never forgotten it, and neither have I. He helped me out also with other of the Portfolio Photographs. After I got set up for some of them, he made the exposures for me. When I fell ill, I think he guided the ones on the Pleiades and Orion. Anyway, that's off the track from the galaxy rotations — but the rotation work did involve Horace Babcock's work on M-31 as, his thesis. He was my first graduate student.

Hetherington:

There was some increasing contact between Mount Wilson and Lick at this time. Wasn't Hubble setting up conferences, and you would go down?

Mayall:

Yes. He had a small group that he got together — he called them kindred spirits. We would go down there to Pasadena very informally. Usually we talked only from an outline or notes. Mostly, we'd just discuss things of mutual interest, and return stimulated and enthusiastic.

Hetherington:

This was especially new for the thirties, wasn't it? Down there. Had it gone on before?

Mayall:

It was new for Lick. These meetings gradually expanded to include more than just work on galaxies. Under Dr. Shane's administration, after the war, he pushed that quite a bit, and we had more or less regular meetings of the staffs about once a year, the joint staffs about once a year, the joint staffs at Mt. Hamilton and then at Mount Wilson. But Hubble started much of that exchange before the war.

Hetherington:

Maybe we could switch to the use of statistics in astronomy? You were involved in that with Neyman^[31] — weren't you?

Mayall:

Well, yes and no. They were really the statisticians, but they became quite interested —

Hetherington:

— why did they become interested in astronomy?

Mayall:

Primarily because of their acquaintanceship with C. D. Shane. He was among those who got Neyman to come to Berkeley, and so he knew him from way back. Anyway, Neyman became interested in the statistical problems in astronomy, not only galaxies but other things, because of the presence in the department at Berkeley of R. J. Trumpler, who taught a course in stellar statistics that was subsequently taken over by Harold Weaver, who is still there.

Hetherington:

Weaver's his son-in-law?

Mayall:

Yes. Weaver married one of his daughters, Cecelia. He married into the Trumpler family, and thus Neyman became acquainted with the astronomers nearby from the very beginning of his affiliation with the university.

Hetherington:

The astronomers were already doing something on statistics?

Mayall:

They were working on astronomical problems, but they were using rather low order statistics, from the point of view of a mathematical statistician. I should like to say, however, that Neyman was one of the few outstanding mathematical statisticians who showed any interest in applying his results, and particularly to astronomy. This is rather unusual for a man of his competence and theoretical bent, to get interested in the observational things. What acquainted me with him was through his interest in counts of galaxies, particularly Shane and Wirtenan’s galaxy counts which were used in a number of papers.

Hetherington:

Shane was working I guess pretty closely with Hubble too?

Mayall:

No. Not too closely. He knew him quite well, but I don’t think he worked as a colleague with him. Of course, he was Lick director when Hubble came up there for some of the later meetings, and so they had — they entertained each other. They were on very cordial terms, but they didn’t have, to my knowledge —

Hetherington:

Was Hubble then using Shane’s counts?

Mayall:

No, because Hubble died in 1953. Those plates upon which the counts were based were taken from 1947 to 1954, and the counting results really didn’t become available until just about the time Hubble died. But Hubble was aware of the counts, and he thought they were great. However, he had no part in the work. The way I was roped into statistics, was that Neyman became interested not only in the statistics of the images of galaxies, but also in the subject of clustering and super-clustering of galaxies, from analyses of these counts, which led him to considerations of stability of clusters. Were they unstable? Were they evaporating? Or were they condensing? He realized, of course, immediately, that you’d have to know something about the velocity field. And so he prevailed upon me to observe a number of, — get a number of new radial velocities of galaxies in the Coma cluster, which I did. I increased the number to about 50. And he included those results in a paper with several other authors.^[32] Also, I had done some other things, involving observations of mine that interested Neyman and his colleagues. They gave me credit — I got in sort of on their skirts — because they used my material.

Hetherington:

They were actually asking you for new observations, too?

Mayall:

Yes, and I also led them to other observations — they were not acquainted very well with the observational material, so I would refer them to it. We had a lot of discussions, too, which from my point of view...

Hetherington:

They would come up to Lick, or you would go down to Berkeley?

Mayall:

Oh, both ways. They came up to Lick many times, and I went to Berkeley on a number of occasions. I was going back and forth all the time, because I also was a U.C. faculty member, as a staff astronomer, and I served on committees at Berkeley — not so many committees —

Hetherington:

You would teach courses, there, but you would serve on the students —

Mayall:

No, I did not teach courses, although from time to time I gave lectures in my field, special lectures. Since I served for a number of years on the Graduate Council, I used to make fairly regular trips down there, and I got acquainted with a lot of the broader problems and policies of the university. I enjoyed that experience very much. It gave me the feeling of getting away from isolation on a mountain top. Some of the astronomers just would stay up there, and dig their grooves deeper and narrower; I decided this was not going to be for me.

Hetherington:

That could be a problem at Lick that I guess you didn't have at Mount Wilson?

Mayall:

No. Mount Wilson was entirely different. Lick, at that time, was fairly well isolated, because transportation was not all that good, back and forth. It still took time to get up and down between Mt. Hamilton and Berkeley.

Hetherington:

It's still 40 minutes, [from San Jose] I think.

Mayall:

Yes, but everything is much better, faster. You have the freeway now, to get to Berkeley. It's no longer an outlying post. Well, that's how I got involved in the statistical papers — but not on the basis of a theoretical or analytical participation at all. Mine was purely observational, helping them to get new data, or suggesting available data, or persons who might provide it.

Hetherington:

I was trying to think if there was anything else, major happenings at Lick, before you go to Kitt Peak...

Mayall:

Yes, from my point of view — there was the 120-inch telescope project. That’s a long, interesting...

Hetherington:

— That was just after the war, right?

Mayall:

Yes. I don’t know where to begin on that, but I felt that, to work in the field in which I was interested, and if I stayed at Lick, we ought to have something bigger than a 36-inch telescope. I gradually persuaded most of the people there that this project was a good thing to go for. I wasn’t the only one, who felt the need for it, but I made the pitch on the basis that many of these faint objects, not only galaxies but stars, clusters and galactic nebulae — and even including planets and satellites... we could justify the need for a larger telescope.

Hetherington:

You were just starting to talk about the 120-inch when we changed sides.

Mayall:

Well, yes. That project goes back to the time when I was at Mount Wilson. I recognized the value, the advantages for research, of the larger telescopes. And particularly, if Lick Observatory was ever going to stay in the race, in the competition, they would need something larger than a 36-inch.

Hetherington:

Did — was there a pretty good sense of competition among astronomers?

Mayall:

Oh yes, very active. Very great rivalry. And, also, I had been associated with most of the men down there, particularly with John Anderson, who was the Executive Officer for the 200-inch project, and I became convinced that the 200-inch was going to be the greatest thing for astronomy, although there were some astronomers who took a dim view of it.

Hetherington:

Why weren’t they enthusiastic?

Mayall:

Well, they were afraid that they would never get one that could properly be controlled, and the mirror could not be figured to the required degree of accuracy —

Hetherington:

It took about seven years to figure the mirror?

Mayall:

It took longer, because it was not worked on during the war. But I guess I was an enthusiast for big telescopes, after my experience on Mount Wilson with the 60-inch, and occasionally with the 100-inch. The time for the latter was so much taken up by older and established astronomers particularly, that I only got to use it very peripherally. But I'd had many talks with Hubble about telescopes, and of course, he was one who urged, advocated and cooperated to get the 200-inch. Much of his research was used to justify its construction. I'd talked to him so much about telescopes that he urged me to go after one for Lick. So I actually started on this project after I got back to Lick from Mount Wilson. My long-term residency up there began in 1932, and nothing much happened, except talk about it, from then until the end of World War II. Of course, I and others left Lick for war work — and so the idea of a large telescope —

Hetherington:

— you worked for the government during the war?

Mayall:

Yes, I worked, mainly at Caltech, for 2 1/2 years.

Hetherington:

What were you doing?

Mayall:

Oh, I worked on a lot of things — the most important was on the A bomb. That's a rather long, but interesting story.

Hetherington:

Someone else will get that.

Mayall:

I will say in this connection, since I mentioned the rotating mirror experiments of A. S. King in the Mt. Wilson Observatory physical lab, that I went and borrowed that device from him, at a crucial stage in the A-bomb project. They wanted to know what components in the detonation system were failing, because they hadn't obtained simultaneity in the implosion process. There were so many components in the chain, they didn't know where to begin, but we licked that problem with the rotating mirror camera. We… Well, that's another story. Anyway, that little toy instrument had been in mothballs. It was put aside on a shelf for many years. I went and asked Dr. Adams about it, he was still director, and he lent it to me, with Ike Bowen's endorsement. We set that thing up, and it was the breakthrough that allowed us to tell them where the problem was, and it was not where they thought. They suspected it was in the electrical device that provided the electrical impulses to the detonators. The first exposure we took of the exploding wires from the electrical impulses was just the typical classical experiment that Anderson had been doing. In our set-up for this test, we put all the detonators in a line and imaged them on the slit of the rotating mirror camera. The film showed streaks from every one of the exploding wires. We could put a ruler straight across where those streaks began, and they were simultaneous to a fraction of a microsecond.

Hetherington:

I guess most astronomers stopped doing their astronomy during the war.

Mayall:

Oh, yes. This wasn't astronomy. This was experimental physics, and we tested what they called a switch. They didn't call it a power supply, but that is what it was, and they thought the problem was there. The very first exposure we took with that little toy instrument showed them it was not electrical. We showed the trouble was in the explosive detonation train, and then we had to find out where. We had to proof fire for simultaneity each component, right up to the lens charge, where the imploding detonation wave emerged. We eventually monitored the whole process with new rotating mirror cameras, developed on the basis of this one from John Anderson's work. Initially they had two approaches to solve the problem. One was electronic, doing things with circuitry and oscillographs. Louie Alvarez^[33] was doing that, he was spearheading that approach independently. We started in, Bowen and I and others, using the optical approach. We solved the problem so fast that the electronicers never caught up — they just folded their tents and vanished. The whole thing is still being done by optical and not electronic means. Anyway, that's another story, probably involving the H bomb. I can't help but note how those little things can sometimes have a major impact on subsequent events. Nobody had any idea, when that little thing was being used to determine atomic ionization levels, that it would solve one of the major problems in the implosion process of the A-bomb.

Hetherington:

How fortunate for them to have astronomers around.

Mayall:

Well, at Caltech of course, there were a lot of astronomers around and a lot of them were out at China Lake (NOTS) — where some of this work was done.

Hetherington:

Some of the astronomers left — I think Hubble went to Maryland, didn't he?

Mayall:

Yes. He was at Aberdeen involved in external ballistics.

Hetherington:

Most astronomers stayed in the area, though?

Mayall:

No, they were pretty widely spread. I just happened to be there at Caltech. When I went there, I didn't know what I was going to work on. For a while I worked on rocket motors for rocket weapons, using optical methods of evaluation of jet blasts in firing bays.

Hetherington:

I guess Baade was about the only one staying at Mount Wilson.

Mayall:

He, Dr. Adams and some of the older ones. But they had a war project going on there under Ted Dunham,^[34] electronice which was an optical program involving identification of airplanes, improvement of aerial camera lenses, of roof prisms and things like this. That was all going on there, but that's a whole other story. Well, to return to a large telescope for Lick — some of us, who were working in the same area down there and had come from Lick, and among them was Jerry Kron, G. E. Kron, who is now living at Flagstaff. He resigned a couple of years ago as director of the US Naval Observatory, Flagstaff Station. He was a staff member at Lick who had left there in 1942 to go into war work, and he wound up at Inyokern, where he later did the outdoor proof-test firing in the Mojave desert, for the A bomb. He and I used to get together, along with some other astronomers there, and we felt that if we were going to go back to Lick — and some of them were undecided whether they were going to return to observatories, or not, because they pay so poorly — we ought to have some worthwhile instrumentation, particularly a larger telescope. So Kron and I agreed that we should go for an 120-inch. We thought this was a good size, in cost what we thought we might get from the State legislature, and between the 100-inch and the 200-inch — something intermediate. There wouldn't have to be any experimental engineering, and we thought we might it with the kind of money that the State would be willing to put up, because the State —

Hetherington:

— The [mirror] blank was available at this time, wasn't it?

Mayall:

That's another story. It proved to be available, but for a while, it was not.

Hetherington:

The blank was physically in existence?

Mayall:

Well, there was a 120-inch Pyrex blank in existence, but we weren't sure that we wanted it, for various reasons. Eventually, it turned out that we didn't have any choice in the matter. Anyway, the university — the President at that time was Robert Gordon Sproul, who was a very far-sighted fellow. He foresaw that, at the end of the war, the university would be faced with returning faculty who wanted to do bigger and better things. He also had a very good lobbyist named James Corley, who was at Sacramento, with many contacts among the legislators there. The two of them worked up a capital facility program for the whole university, and the President asked each component of the university to submit ideas, plans, and estimated costs for what they wanted. When it came to Lick, Jerry and I heard about this, and we got the director to submit a request for a large telescope, a 120-inch telescope project, and we made a rough estimate of the cost for budgetary purposes only, of $600,000. In those days, that amount was reasonable enough. Now, of course, it's hundreds of thousands so far beyond, that you would never think of it as adequate.

Hetherington:

That was probably a lot for the time.

Mayall:

Anyway, (crosstalk... it got a 120-inch telescope for Lick in the President's post-war research facilities budget. But this was a separate deal from the regular U.C. operating budget.

Hetherington:

This was something that hadn't been done before?

Mayall:

No. Oh no. It got to the state legislature, and they set hearings in Sacramento. Dr. Shane, who was then Lick director, was asked to go there by Jim Corley, and Dr. Shane asked me to go along with him. I think he wanted to have some enthusiastic backup, in case somebody asked him about the rationale for big telescopes. So we went down there, and I'll never forget that evening. It was some kind of a small hearing room, but not in the Capitol building. There was a stage, and it looked like they'd obtained a small theatre or school. My recollection is that we never got a chance to say a single word. There was a bunch of legislators, 15 or 20 of them, who sat up there on the stage, and they were going over this big budget for facilities for the university, and there were all sorts of projects. Then one fellow said, "Well, there's one item here I want to bring up." We pricked up our ears. He continued, "Lick wants a big telescope," and he proceeded to give all the reasons why we shouldn’t have a big telescope. Too much money, when other more human needs would require funding, it was too far-out, this kind of money, and we shouldn't spend this kind of money at this time for that thing. Well, there was some discussion, but Dr. Shane was not asked to say anything about it. There was just talk between the committee members of the legislature dealing with this budget. It’s hard to believe that the director of the observatory was not asked to say a thing.

Hetherington:

Yet you were right there.

Mayall:

We were sitting right in the audience there. He was all primed, and so was I, as a backup, if he needed me. Well, they had about a five or ten minute discussion, and then they voted to knock it out of the budget. You can imagine how we felt. The hearing went on, through the rest of the items. We sat there, feeling pretty gone. Then it adjourned and James Corley, who’d been sitting up in the front row, came down the aisle and said, out of the side of his mouth, “Sorry, fellows, you lost your telescope.” Well, I can tell you, there were a couple of pretty dejected astronomers on the way back to Mount Hamilton that night. Although we didn’t know it, we were pawns in a political ploy. The legislators wanted to have something to bargain with, an item to put back in, if the Governor would put something else in, which was what was called the “Christmas Tree Fund.” This was a section, needing the Governor’s approval, to include 75 million dollars for several of the legislators’ districts for special “things” for their constituencies. Nobody knew how it was going to be spent. It was a great boondoggle, of course, and it would have gone down so many rat holes that you never would have seen what happened to it. But that was not proposed by the governor in his general budget, which included the new facilities budget for the universities. The legislators weren’t about to approve the governor’s general budget. They wanted him to include the Christmas Tree Fund, and had everything all planned, I guess, as to how to dole it out in patronage. This item got a lot of publicity and was called a lot of dirty names, and it really became a cause celebre. But you know what they did? They bargained that fund and the telescope, saying in effect, “We’ll put back the telescope — if you will put in the Christmas Tree Fund.” Well, they all finally agreed, so the telescope got in the budget, at $600,000 along with a $75 million boondoggle! However, inflation started, and the university began to expand, and need more and more money. Year to year, they increased their funds for cost of living and expansion, and finally when we actually started to get serious about a 120-inch, — it was budgeted at $900,000 for the telescope and dome. In addition, the budget included an item for instrumentation at one-third of the telescope and housing, so the total funds that was authorized, when we were ready to make the contracts, for construction was $1,200,000.

Hetherington:

The state had a lot of money after the war, didn’t it?

Mayall:

Oh yes. And the state was very well disposed towards the University at that time, because of the way Sproul had been handling things.

Hetherington:

I suppose Lawrence’s^[35] work was pretty impressive.

Mayall:

It’s a long story. We couldn’t have tried to start that telescope project at a worse time, because the money was authorized about the time the Korean War broke out, and you know what happened then. Prices started to go up, and firms that were interested in bidding on it vanished. When it came to asking for bids, we got a single bid, from the Judson Pacific Murphy Company in Oakland, and there was great question in our minds whether the legislature would free that money on the basis of a single bid.

Hetherington:

Was it mainly for the mounting at this point?

Mayall:

It was for the telescope, mirror, and mounting, not the dome. The dome was a separate contract.

Hetherington:

Did they subcontract out the mirror, or did they have the ability?

Mayall:

We did the mirror ourselves. We set up the facilities in the basement of the large building and dome of the telescope. Also, we had a heck of a time getting that money released, because there was no competitive bidding for a contract. It was a reasonable bid, we were convinced of that, but we had to defend it vigorously.

Hetherington:

It came in under the $1.2 million?

Mayall:

Yes, it came within that sum, but we had to keep enough differential for the instrumentation and for the dome itself. And so, when the pitch was made to free that money, to negotiate this contract, there was a special committee of the legislature set up. It met in Los Angeles, and the President may have gone down, or had to be backed up — I don’t know who else, but some scientists were involved. I think they were brought in from outside, maybe Caltech. I was not involved in that. But they had to do a lot of convincing, to get this legislative overview committee to free that $900,000 Fortunately, they did. But it was, I think, a little bit of nip and tuck. That was really when the die was cast. I can’t remember if the year was 1949 or 1950, but we requested the bids in 1950, and they were awarded to a single, sole contractor. Then we had troubles getting the mirror blank. We’d requested bids on a Pyrex solid blank, because we didn’t favor this rib structure too much, because of the difficult experience they had had with the 200-inch, which never has been much talked about, but that —

Hetherington:

— I didn’t know there was a problem.

Mayall:

The problem was to find a support system that would have low friction, and also support that mirror rigidly enough, with the reduced thickness of the solid slab on the rib structure. A rib structure like that is nowhere nearly as rigid as a solid blank, and, of course, we knew this. The 200-inch project engineers had actually designed and built two or three complex mechanical mirror support systems, before they wound up with one that worked.

Hetherington:

This was for Mount Wilson?

Mayall:

No. This was for the 200-inch on Palomar. They licked it, but at considerable extra cost, time, and great mechanical complexity. We wanted to avoid all that by having a solid blank, but we found out that we couldn’t afford it. So we were forced to buy the 120-inch ribbed blank that they had at Caltech, and we bought it for $50,000. It was almost a give-away at that price, but to ask Corning —

Hetherington:

How much would it have cost you for a solid one?

Mayall:

I cannot recall the details on that cost, but it was some hundreds of thousands of dollars, because Corning had gone out of the mirror-blank business at that time. They’d have had to build another whole factory, like they did for the Palomar mirrors, and we'd have had to pay for that whole new installation. We simply couldn't afford it, and that’s why we settled for that particular ribbed blank.

Hetherington:

So this time, no one was really casting large discs.

Mayall:

Well, they would do it for a price.

Hetherington:

But you’d have to pay to build the whole factory for them?

Mayall:

Yes. And then, of course, they could run off others for other places if they wanted to, but we didn't have that kind of money to do it. Well, the telescope and dome finally got built, with delays, interruptions and difficulties because of the Korean War. But we did get it built, before Dr. Shane retired in 1958. When Whitford^[36] came there, the figuring of the mirror for the telescope was pretty well along. During the first half of 1960 we were still figuring and testing the blank — I was involved in the Hartman testing of it, with Stan Vasilevskis. We finally reached the point where we were willing to say it was good, or good enough, provided the mirror support system worked. It was becoming evident that, with some minor changes, we could probably make it work. But we couldn't really get it installed on a permanent support system until we finished figuring the mirror, because there was a lot of grit and water and clean-up involved, and we didn't want that pollution to get into the mirror support system, which was a very delicate lever system. So, we carried the final figuring and testing to the point where we felt it would work OK, and we were able to get the first photographs with the telescope in the late spring of 1960. I worked with it in June, 1960, taking some of the first nebular photographs. Then I had to quit, in September, to move and start work here in Tucson on October 1, 1960.

Hetherington:

Kitt Peak was just being built from scratch then?

Mayall:

Kitt Peak had been underway — they had, of course, selected the site, in March, 1958. They had started the headquarters buildings here, and they had adopted a master plan for Kitt Peak.

Hetherington:

This was a number of universities together?

Mayall:

This project was being operated, or done, by the Associated Universities for Research in Astronomy, known as AURA. It was the university consortia formed in October, 1957, to get a grant and then a contract for this job. They were well into it before I came, under Aden Meinel's direction. He was the conductor of the site survey program, and became the first director. When he stepped down in March, 1960, they began looking around for some other fellow for the hot seat, and I agreed in May to accept the appointment. I don't regret it. I realized that I would be giving up my research career, but by that time, I'd been rather long (28 years) on a mountain top, and my family felt differently about staying there.

Hetherington:

Lick School only went to, what, 6th grade or so? Before the children have to start going down the mountain?

Mayall:

Yes, through 8th grade; and living on a mountain, for families, is not a good thing, really, but that's another, whole drama. Of course, when I started, there was little alternative. But I think the move down, for everybody, was too long delayed. I think we should have made the move right after the war, to Berkeley, rather than to Santa Cruz. But the staff didn't want to, and I was among them. It was much more expensive to operate the Observatory with all that housing up there, and it was a pain in the neck to the director. He had to be a small city manager. He had to adjudicate all sorts of squabbles related to the housing, because it was all observatory property, the housing and support buildings. Oh, you can't imagine the squabbles that revolved around such silly things in the housing — like painting room’s different colors, fights between pets, rows about the school and its teachers, etc.

Hetherington:

It was all university property; you had to get permission to repaint?

Mayall:

No, but many times the residents were very unreasonable. Of course, they didn't have to pay for it, but if they'd had to pay for it, it would have been different. And, some of those people were awfully difficult for the director to handle. He had to be Solomon.

Hetherington:

That does make it more difficult, everyone having to live in one small area.

Mayall:

It's fine in many ways, for the astronomers as a professional activity area, because you're so close to the telescope. I could get up to the Crossley in a few minutes from my house, which was right below the dome. If anything went wrong up there, some visitor working with it, he would just come down and ring the doorbell — and I would go up and try to help him get going. I usually could.

Hetherington:

The instrument shop right there?

Mayall:

No. The instrument shop was farther up the mountain, near the schoolhouse.

Hetherington:

The instrument shop's still there, isn't it?

Mayall:

It's still there, but it's now used chiefly as a maintenance shop. The main instrument shop is now on the Santa Cruz campus.

Hetherington:

For the Crab Nebula, then, it would have taken you several days if you'd had to go up and back.

Mayall:

Oh, yes. It could have delayed things, probably a week or more. But a lot of this is hindsight, 20-20 hindsight. We weren't as wise as we could have been. I think we should have moved to Berkeley instead of Santa Cruz, the way it turned out. But when the staff moved to Santa Cruz, they did so with the expectation the campus was going to develop into a major campus, with other graduate departments in the related science — in math, physics, and geophysics and so on. If that had happened, it would have been OK. It would have been another version, probably not exactly similar, but maybe with the same resources, comparable to Berkeley — and that would have been fine. But the legislature dragged its heels, and didn’t provide the funds for the expansion of that campus at Santa Cruz in this manner. And so the Lick staff is nearly all by itself down there as a research organization.

Hetherington:

You didn't get any stimulation from physics and math?

Mayall:

I think they need their cohorts, or if not cohorts, their peers —

Hetherington:

There was a lot of that at Caltech, wasn't there?

Mayall:

Very much so, and it makes a big difference. And, I'm convinced, it is vital for science. [Some conversation about Kitt Peak inadvertently not recorded at this point.]

Hetherington:

In particular, do most of the observers come here for short periods, or do you have your own staff too?

Mayall:

Well, there's a resident staff and visiting, guest scientists. The resident staff, by policy decision of the board of directors, gets 40 percent of the available observing time. That time is fairly flexible, and it's a nominal amount that can go above or below by about 10%.

Hetherington:

Astronomy has changed quite a bit over the years you've been in it, hasn't it, in operation?

Mayall:

Oh, my, yes. It's so revolutionary, especially in instrumentation, that I can't really call myself an astronomer anymore. I have not conducted a personal research program since I left Lick. I didn't expect to.

Hetherington:

Directing here took all that time?

Mayall:

Not only here, but the initiation and the establishment of one in Chile. That happened within a year and a half after I came here, and that project came on, or we took it over formally May, 1961. Hell's bells, it wasn't a year before we had it — but we didn't know it was going to build up to what it is now, especially with another 158-inch telescope. We had no idea it would be that big. We had no idea the number of telescopes there would be so large, and that other universities and observatories would want to locate their Southern Hemisphere telescopes there.

Hetherington:

A really rapid expansion?

Mayall:

The two — I'd say that for these two developments, it was a 24 hour a day, seven days a week job for me. I took very little vacation, and fortunately my health held up. I was shuttling back and forth all the time, to Washington, and several times a year to Chile, and was responsible for everything. They didn't have a paid president then, so the director had to do many of the things that the President is now doing. This was one of the things I hoped to have happen, and it occurred not long after my retirement. At my urging, the AURA Board agreed to hire a full-time, salaried President, so my successor might have some relief of the administrative burden, and possibly be free for some research. I advocated that very strongly, on the basis of my 11 years’ experience; I think that was right. I don't know whether Leo Goldberg has been able to do much research, but he's kept his finger in it, I hope, more than I did in my field. But the thing that's happened, in my field of special interest, galaxies — the new developments in detectors and computers and processing of data, is so revolutionary, that I can't begin to operate that equipment, at a telescope, without a whole cadre of people to tell me what to do! I'm not sure I could even propose a realistic observational research program, because I don't know what these new instruments can do.

Hetherington:

Being director, you've probably seen the new fields rising, and competing for telescope time.

Mayall:

Oh, yes, of course. And competing for plans for development, too. That was always the hairy question — how much do you put in this field, how much in that field?