Oral History Transcript — Dr. James Baker
This transcript may not be quoted, reproduced or redistributed in whole or in part by any means except with the written permission of the American Institute of Physics.
This transcript is based on a tape-recorded interview deposited at the Center for History of Physics of the American Institute of Physics. The AIP's interviews have generally been transcribed from tape, edited by the interviewer for clarity, and then further edited by the interviewee. If this interview is important to you, you should consult earlier versions of the transcript or listen to the original tape. For many interviews, the AIP retains substantial files with further information about the interviewee and the interview itself. Please contact us for information about accessing these materials.
Please bear in mind that: 1) This material is a transcript of the spoken word rather than a literary product; 2) An interview must be read with the awareness that different people's memories about an event will often differ, and that memories can change with time for many reasons including subsequent experiences, interactions with others, and one's feelings about an event. Disclaimer: This transcript was scanned from a typescript, introducing occasional spelling errors. The original typescript is available.
See the catalog record for this interview and search for other interviews in our collection
Interview with Dr. James Baker
James Baker; June 9, 1980
ABSTRACT: In this interview, James Gilbert Baker discusses: his family and childhood; William Marshall Bullitt; Harlow Shapley; University of Louisville; Walter L. Moore; American Association of Variable Star Observers (AAVSO); Richard Prager; Harvard University; Bart Bok; Otto Struve; A. Pannekoek; Cecilia Payne Gaposchkin; Ted Sterne; Don Menzel; E. Bright Wilson; Leon Campbell; Lawrence Aller; Rudolph Langer; Henry Norris Russell; S. Chandrasekhar; Joe Boyce; George Harrison; optics; Leo Goldberg; Harvard Society of Fellows; Ivan A. Getting; atomic bomb; Lise Meitner; Niels Bohr; R. W. Wood; aerial photography; Ted Dunham; Fred Whipple.
DeVorkin:Dr. Baker, I know you were born in Louisville, Kentucky. Could you tell me something more about your family background and early life?
Baker:Iíve looked into my family background rather recently because of a general interest in roots and family, and Iím pure Kentuckian. My forebears that I know of were all Kentuckians, till the earliest times, when they came from Virginia. I managed to trace back to about 1715. There was a James Baker in Virginia, first of that name that I know of; who lived in Halifax, Virginia, and probably was a clerk in a court house late in the 18th century. And his son Martin, one of some children, migrated to Kentucky and apparently near Lexington, Kentucky, somewhere near the Kentucky River. His house, I understand, is still there, modified over the intervening decades, but the basic house is still there. On my fatherís side, the succession was all Kentuckians up through the present time. Iíve traced back a little bit and found that my great-grand father on my fatherís side was a Southern sympathizer during the Civil War, which was unfortunate because he was executed by the Unionists when they were stationed in the region around Warsaw, Kentucky, on the Ohio River. The family story is that the boy next door, on a neighboring farm, had been a member of the Southern cavalry, and had come home in advance of Morganís Raid, I think in 1864, the second raid, to give information to Morgan in advance of the actual raid north. The second one, because the bigger raid was in 1863. And so in any case, my great-grandfather knew this boy and apparently gave him lunch. The boyís former girlfriend, who had been with the Union officers the past two years told on him. So they sent the Unionists down and they retaliated by executing both my great-grandfather and his friend. Thatís a family story.
DeVorkin:That certainly is. What about your intellectual or professional background.
Baker:Well, the history of Kentucky, as you know, is primarily agrarian, through the 19th century. So my forebears for the most part were struggling with the fact that theyíd come from their own forebears in Virginia and had become farmers for a while, including my motherís side. The first university life in the growth of the family began with two of my uncles, one of whom became a Methodist minister and another became a doctor; an eye, ear, nose and throat specialist. My mother was related to Governor Breckenridge of Kentucky, whose name is still used in the state.
DeVorkin:What was your fatherís occupation?
Baker:My father was a wholesale clothing merchant. He traveled extensively through the South, to earn his living that way, all the time from about 1905 until the Depression came along, around 1930. After that, he and one of his brothers set up a hardware and specialty store in Shelbyville, Kentucky, where my father worked until he died in Ď51. I mentioned two of my fatherís brothers already, the doctor and the minister. But his oldest brother, in the twenties ran for Mayor of Louisville, unsuccessfully, but he was prominent in local affairs. And he was the one who joined with my father to have the store in Shelbyville. The depression upset everyoneís lives, of course. In my own case, as a young fellow, I was graduated from the Manual High School in Louisville in Ď31.
DeVorkin:We want to go back and talk about your own training. I didnít ask you about your fatherís training yet.
Baker:He had very little. No college, although as I say several of his brothers did. And my mother likewise. She was born and brought up in Taylorsville, which is a town about 50 or 60 miles from Louisville. Her parents were farmers too. So she was not ever given the opportunity of having any advanced education. But even in spite of just a grade school education she had studied Latin, for instance, and she maintained a steady interest in schools for her own children throughout all our lives. She died in Ď54. She would have really benefited greatly from advanced education, but in that part of the country there werenít the opportunities.
DeVorkin:As you were growing up, say between 10 and 15 years old , what do you remember of your early home life that could have been an influence on your later life, especially your entrance into science?
Baker:Well, I would say that the constant stress in my family on quality work. At first I was too young to know about consequences, but my mother always insisted on our doing the best that we could at every stage in school. The teachers likewise were very solicitous of our efforts, and so by the time of the 5th grade, I was working all the time on interesting things in school; special projects as well.
DeVorkin:What were they?
Baker:Well, we did some biological specimen work, for instance, and photographic recording of the first flowers and ferns. We took field trips in the beautiful park system of Louisville. So I had some training in that way early. But nothing involving astronomy until high school. We knew nothing about physics either, but I would say that I was interested in nature. I certainly was outdoors a great deal and made full use of the park system. I did a great deal of walking around. Of course, we lived on the Ohio River, so I was familiar with river activities. We lived in the western part of Louisville, which is in the bend of the Ohio River, so I was fascinated by the river itself. Not that I ever really went out on the river. I just went along the borders.
DeVorkin:What books did you read at that time, do you recall?
Baker:In that time in Louisville, which was about 1927, there was a great deal of local interest in opportunity classes, so called.
Baker:Opportunity classes. I was sent from the Henry Clay School as their representative, in that particular year, to a so-called Western Departmental School, which is not really called a junior high school, as far as I can ever remember. But it was of the same general nature. I completed my 7th and 8th grade work there.
DeVorkin:This was based on a competitive exam that you went there?
Baker:It was just on general high standing. I remember we had a system of grading, not the ABC business, but ďEĒ for excellent and ďVGĒ for very good and so on, and my report cards were usually Eís and some VGís according to the subject. I was at Henry Clay from the 2nd through the 6th grade. I think I was sent because I had a fairly good record during those years.
DeVorkin:Was this record specifically in any subject or all subjects?
Baker:Well, there was first a one room school where all subjects were taught by the same teacher. We didnít migrate between classes as we did later on. So, when you ask for particulars, in the 5th grade, the teacher herself would separate out the schedule during the week into history and English and reading and arithmetic, that sort of thing. But I donít recall that we had anything we thought was unusual. I think I went to the Western Departmental because simply of my record.
DeVorkin:At that school did you have specialist teachers, by that time?
Baker:Yes. That was organized in the manner of a modern junior high, actually. For instance, I started Latin right away. Again they graded on the E and VG basis. I had Eís ion English, so after a year and a half I was allowed to skip the first semester of high school for that reason. So actually I was at Western Departmental just a year and a half. I would have started in the fall of 1926 and left in February of Ď28 to go to high school. I had a year and a half of Latin there, and continued all through high school afterwards.
DeVorkin:You mentioned you didnít know physics or astronomy until high school. That means you had no science really?
Baker:Well, we had science. Oh yes. Even in 1927 in the junior high departmental library. I remember reading about Newtonís telescopes and stars, and I got familiar through that and through Boy Scout books on the constellations.
DeVorkin:You were in the Boy Scouts?
Baker:Just briefly. My brother went all the way through, but I tried it and didnít actually stay with it. But I had the Manual, so I knew about constellations and did some field work, you might call it, that way. But already in junior high I was aware of the Solar system. It was very attractive to me to know about the scale of distances, because when youíre coming from nowhere, itís very striking to begin to realize how far away the sun is, for instance. That seems trivial nowadays. At the same time in junior high when I read about Newtonís life, why, I was aware of his having built a telescope and elementary things.
DeVorkin:Did that interest you?
Baker:Oh yes. Decidedly. If I had known about the amateur telescope makers in that early time, I would have tried it immediately. But there wasnít anybody around to guide me.
DeVorkin:Did you talk to anyone? Did you have friends your age?
Baker:There was no one, up to that point, that I knew who could have given me any advice. That came later, in high school.
DeVorkin:Ok, maybe we should move on to that. First, give me your, names of your brothers and sisters and your family order, where you were born.
Baker:Iím the youngest. My oldest and only brother, oldest in the family was named Kenneth Blanton.
DeVorkin:Give me an idea of what he turned out to do.
Baker:He went later to the University of Kentucky and became a graduate engineer, and worked all of his life with the Aluminum Company of America. Heís now retired. The next in line was my sister Dorothy, who is still alive. She was trained through the University of Louisville, but not all the way through. She left before she got her degree. The University of Louisville was our local college. Itís since become the Louisville campus in effect of the University of Kentucky system. But in the twenties, it was a municipal university. Iím very proud of it, as a small university. Even with my Harvard experience, I think they did extremely well. But of course, from a local point of view, it was kind of a diploma mill for most of the people around in the city. But it did offer the opportunity, for those who wanted to go on, to really be able to do something.
DeVorkin:What did your sister Dorothy major in?
Baker:She was interested in drama for a while. I donít think she had any particular concentrated interest, aside from drama. But she became married. Her husbandís a dentist, also graduated from the University of Louisville, so I think she left about that time. My next sister Mary Alice also went to the University of Louisville, and she wasnít able to finish because of the Depression principally. Her records werenít sufficient for a scholarship, so she dropped out and went to work in the early thirties. Then she married too in Ď36. And then myself. There were four of us.
DeVorkin:Ok. Itís a good point to ask then at this time if you didnít get scholarship money, does this mean that you couldnít have continued in college?
DeVorkin:Your parents werenít able to support you?
Baker:Well, in a nominal way, but not college fees, no. That is, our home expenses were adequately provided for. But they never really had any extra money for university life.
DeVorkin:Letís move back to your high school, unless there was a comment you wanted to make?
Baker:Well, there was a transition, then, from Western Departmental in February of 1928, to high school days. Incidentally, years later I had to write this up at a very high clip on a typewriter. We might come to that. William Marshall Bullitt, the lawyer, years later, when I was interested in coming to Harvard, had me come to his office and had me sit at a typewriter and type out all these early things. Of course heís long since dead and that record probably doesnít exist anymore, but in terms of a factual account, thatís much more accurate than anything I can remember now, I Ďm sure.
DeVorkin:What was his purpose in having you do this?
Baker:Well, he was an unusual character. He knew Harlow Shapley very well. Iím jumping four years ahead of the story.
DeVorkin:Go ahead, thatís all right.
Baker:In 1935, when I applied to come to Harvard, to MIT and to Wisconsin, I was quite lucky. In fact, in practically the same mail I received offers of scholarships from all three institutions. But I was most interested in astronomy. The one from Shapley had referred me to Bullitt, because he knew Bullitt in Louisville.
DeVorkin:Oh, Bullitt was local?
Baker:He was a local lawyer in Louisville, a very highly placed lawyer. He also had a New York Law office with the New York Life Insurance Co. I guess his cousin was our ambassador to Moscow in the thirties. I forget his particular name, but it was a very well-to-do wealthy family. New York Life, so we were told, paid William Marshall a million dollars for one project only in the Depression. It would be like 40 million now really, but not quite. So Bullitt as a favor to Shapley, asked me to come to his office. He also took me to his home. I stayed there overnight, I remember, one time. But he was a very nervous individual, very demonstrative. He was not overbearing but just assertive. There was never any question of challenging anything he might order. Maybe his wife did but not anyone else. So it was an experience to go to his mansion. These memories come crowding back.
DeVorkin:Sure, thatís all right, just let them come.
Baker:So, became of this, Bullitt had me write out my lifeís history, but I think it was primarily for him to see if I could , under pressure, give a rational discourse. I was only 20. I graduated from high school when I was 16.
DeVorkin:Right. This was when you graduated from the university.
Baker:From the University of Louisville in Ď35, which was when I was 20? So, I typed five or six pages at 50 or 60 words a minute.
DeVorkin:Was this sent to Shapley?
Baker:I have no idea.
DeVorkin:So if anywhere they would be in Bullittís papers in Louisville?
DeVorkin:Ok. Letís go back to your high school and talk about your first contacts.
Baker:I went there in February of Ď28.
DeVorkin:Which high school was this?
Baker:It was called the DuPont Manual Training High School. But as I say, Iím rather proud of what Louisville people were able to do under somewhat primitive circumstances. This is important in my later life because I not only had all the prescribed courses that one would find, including 3l/2 years of Latin and exposure if I wished, but I didnít at the time, to French but full courses in English, history and political science and such things were all given there. But in addition, we had to undertake engineering drawing for four years, and we had some exposure to shop practice. It was not drastic; we had to do things like design a house, as part of our four year drawing course. In our senior year, we had to design a complete house from top to bottom. I also had surveying. I was given six months of surveying, where we did some surveys in the local streets and the local parks. So I became familiar with instruments. We also had full courses in algebra, geometry and trigonometry; had two years of chemistry and two years of physics. It was a full program. I usually didnít get home until 4 in the afternoon. It was much harder, I think than present day high school programs. We also were given to believe all the time that quality was a worthwhile goal. So, as a result of that, at my motherís instigation, I and my brother made a good record in the same high school. I was valedictorian.
DeVorkin:This was at your motherís instigation?
Baker:I mean she always made sure that I was doing my best.
DeVorkin:Oh, I see. She pressured you, she didnít pressure the school.
Baker:Oh, no. She certainly saw the worth in all of this.
DeVorkin:What about your father, did he?
Baker:He was sort of an introvert, quiet. He loved to read. He spent all of his spare time at home reading, but he didnít really talk very much. He was quiet. But he too had a good mind, I know. And he was interested in my success, but he wasnít assertive about it. My mother insisted on it.
DeVorkin:Did they push you in any particular direction?
Baker:No. I had any choice I wished to make. I suppose if Iíd become a Buddhist or something of the sort, they would have objected. If Iíd gone in some odd direction, there might have been some such thing, but my interests were practically along the lines of physics and chemistry. At that point there was no astronomy in Louisville in high school days, but I continued reading about it, and by the end of high school Iíd read Youngís Astronomy, which was used in Princeton. Itís an older book, to be sure. Charles Young had been at Princeton University preceding Henry Norris Russell, and his textbook in astronomy was rewritten and vastly enlarged by Russell, Dugan and Stewart. But it was Youngís Astronomy that I had access to and did read in high school.
DeVorkin:So you didnít see ďRussell, Dugan and StewartĒ in high school?
Baker:No. I did not, no. It wasnít in our library.
DeVorkin:Was that Youngís Manual?
Baker:Yes, the Manual of Astronomy.
DeVorkin:Through high school did you talk with anyone about astronomy or your future interests in science, if you had them yet?
Baker:The Louisville High School system was separated. They had separate girlsí high and separate boyís high. And in those days, there were two boyís high schools, ďMale High,Ē it was called, and ďManual.Ē So we knew nothing about what went on at the girlsí high. But at Manual then, to speak of my friends, they were all boys. Some of those I was with went on to become doctors and lawyers. But at the time, we were all just physically active. We liked sports. We liked high school sports. We didnít ourselves go out for any, but there was a Scholarship Club, so called. The boys who liked to study and read, including myself, all belonged to that. And we got interested in chess, and, gave that a good workout.
DeVorkin:So your astronomy was very much on your own, through your reading.
Baker:Oh yes. It was. I donít believe I talked to anyone.
DeVorkin:Did you do any term paper projects, anything in drafting?
Baker:I was very active in high school because in those days I didnít attempt to narrow my interests. I was interested in anything I had time to read or work in. I remember, in my senior year, I was editor of our school paper. Our family affairs were going downhill, as everyone elseís was in the Depression. My father lost his job in 1930, and was setting up in Shelbyville. That is when he set the store up with my uncle. We were all of course in somewhat of a state of depression inside the family and it put a damper on a lot of our activities. An uncle on my motherís side came to live with us to help out. Also my grandmother. But she was 73 and rather nervous, so she preferred to go back and live by herself again. She died shortly afterwards. But my uncle had a large collection of books, and he also had a telescope.
Baker:I wish I could still have it. It wasnít a great one. It was French made refractor, a very nice little telescope. I admired it but I didnít dare actually use it, for a while anyway.
DeVorkin:What size was it?
Baker:It was only a two-inch. It wasnít anything tremendous, but bigger than anything Iíd seen before. Oh, yes, my memory has come back — just to put some milestones along the way — I was greatly interested in the solar eclipse in Louisville in January 1925. It wasnít total in Louisville. It attracted attention all over the country, but of course along the path millions of people saw it. It was good weather, I believe. In Louisville we were south of the line so it was a partial eclipse. I got out our box camera and took pictures of it. I still have them in the old family album somewhere. But that was an early time, because I was ten years old then. So I think that I did have something to do with it — the general interest and the newspapers were full of stories of eclipses and so on. That had a lot to do with it. Letís see, there were no other events of that kind, I guess.
DeVorkin:In your local public library in addition to books, did they subscribe to Popular Astronomy?
Baker:No, it wasnít there. Nothing was there. Not even in high school. I think we were a little bit mistreated that way. That is to say, If there had been any people among the staff who had been especially interested in astronomy, that would have helped me enormously, but I didnít know that. But that did happen in the university later.
DeVorkin:There was no question that you would go to the University of Louisville?
Baker:Well, there was a quest ion whether I was going to any university. I was valedictorian, to be sure, but we had no money. In that spring of Ď31, when I was graduating from high school, my mother had taken in an orphan, really a waif, in conjunction with the welfare people of Louisville to earn a little extra money. They paid something like two or three dollars a week for each child that was boarded, which was equivalent to $15 or $20 a week. So, that has no particular reference to my own interests, except that it brought me in early contact with Dr. Walter Moore, who adopted the child. He was of course a fairly young person himself. I remember when he came to our house to arrange for the adoption. Shortly afterwards that fall I met him again at the university, and he was the one who was interested in telescopes and amateur astronomy! So that was my first contact, although of course I didnít know it at the time that was six months before. Itís interesting how oneís life is sort of tied around in those patterns — Well, during the summer of Ď31 I didnít even think of university. At least I didnít take it seriously.
DeVorkin:Well, did you work that summer?
Baker:I did some work. I played the trumpet so I did some work playing in a dance band. All through junior high and high school, Iíd played in the school orchestra and the bands. And in college, I played in the university orchestra. Then also during my college years, I played in the Louisville Symphony Orchestra, which was not a big name in those days became it was just beginning. It was really a private small scale orchestra, but years later it did indeed become a good orchestra but I was in on the very beginning of it. So I played second trumpet in the Louisville Symphony Orchestra, but I played first trumpet in high school, orchestra band.
DeVorkin:Did you have any other employment at any time?
Baker:These were nominal things. In earlier times I just did local work in Louisville, you know; cutting grass, work in the drug store, running errands, sold magazines, anything I could. I worked in a local grocery store. Those werenít very significant. It was just to earn a little extra money.
DeVorkin:But there was a serious question when you were about to go to the university.
Baker:Yes, and as the summer wore on we moved to the outskirts of the city to lower our expenses. And then Iím not sure exactly what happened, but my mother complained, (you might call it that) to the university authorities by letter. So the university president went out of his way to set up a scholarship plan, not just for me but for valedictorians in real need. So the scholarship money needed wasnít very much. It was $150 tuition, but if you use a factor of 20 for today I suppose itís very significant. You might argue in 1931, on a scale d 20 but surely not 10. Harvard in those days was $400, I believe, and for many years after was $400 a semester.
Baker:Just tuition. Louisville was $150 and in addition there was a $50 general fee. So it was $200, which nowadays seems like nothing, but it was a real major road block. In any case, in a matter of just several weeks, in September of Ď31 the scholarship plan was just inaugurated, and Iíve always felt that the president himself put the money into it. I donít know that. You might find out.
DeVorkin:How far away did you live from the university? Did you continue to live at home?
Baker:I lived at home. It was about four miles. I went in on the street car system. At the very beginning of the university life, they gave us sort of a blend between IQ and achievement, and I scored highest in the entering class.
DeVorkin:You were number 1?
Baker:Well, they told me I was. That had something to do with the scholarship. Professor Freeman, who was in psychology, administered the test, and he was the one who told me that Iíd scored highest.
DeVorkin:Did anyone at that time ask you what your career plans were? Or were you making your mind up?
Baker:We were not required to. It was a liberal arts college, and you were supposed to just take a standard set of courses. During that period I was in the university, Ď31 to Ď35, they were experimenting with different types of required courses. The result was that I really graduated having taken two separate sets of requirements. So I had more work rather than less on that account. In my first year I had French, philosophy (this is my freshman year) college algebra, ancient history and English. Those five subjects. In addition I was with the orchestra. Later I had chemistry. But I had a year of chemistry in high school and I was a little upset because we were repeating principally what Iíd learned in high school over two years. So I regarded my college chemistry as kind of a waste of my time.
DeVorkin:Did that decrease your interest in it?
Baker:Yes, it did. Oh yes, it did.
DeVorkin:What about your physics?
Baker:Physics was sophomore level. I had two years in high school but I donít believe I had any physics in the first year in college. I had three years of physics in sophomore, junior and senior years, with a full array of physical subjects in college. But the first year again was largely a repeat of high school physics.
DeVorkin:Do you remember any particular courses that intrigued you? Did you have modern physics?
Baker:In my senior, yes. Yes, we had quantum and nuclear physics insofar as those were known in those days, at the college level. One of the worries that Shapley had was that my training in Louisville might not have fitted me well enough to be at Harvard. But I think he discovered that it did during the period of transition.
DeVorkin:What professors do you recall from Louisville?
Baker:I majored in mathematics, as it turned out.
DeVorkin:How did you decide that?
Baker:Well, Dr. Moore was a mathematician, and he was the one who was an amateur astronomer and telescope builder.
Baker:So it was a natural thing. But also he was a second [???] the math department, there were only two, and so we had practically the tutorial system. Dr. Stevenson was older and head of the two man department. So we had an intimate contact for four years with both men. We had formal classes because after all they taught college algebra, with calculus, and many people had to take that, especially the premed and pre-dentists. I had calculus the beginning of my sophomore year. After the larger portion of the class would leave, why, then I would stay around and work with the mathematicians directly. So I had a very, very good workout, and when I graduated I had two, maybe three extra courses above requirements. This helped.
DeVorkin:What students, colleagues of yours, do you recall who later went on into science?
Baker:Well, not many went into science, I guess. Louis Lusky was one who came from Male High to the University of Louisville, and while our paths were parallel, they didnít really cross very much. He was interested in Law and I think later on he became a full-fledged lawyer and worked with a Supreme Court justice and I believe he practices Law in New York City. He has a separate career and Iím sure a very able one. Lusky was first rate. Then there was a boy named Edward Lotspeich who was also interested in astronomy. He became a physician in later years. I believe he was interested in astronomy and built his own telescope.
DeVorkin:Thatís important. Were you around when he did that?
Baker:Well, I built my own. I didnít see his, but I built my own, with Dr. Moore assisting.
DeVorkin:So you did that in your university years?
Baker:Oh yes, early. I can trace exactly what happened. When I became interested in telescope making, through Dr. Mooreís interest too, I tended to work independently. He didnít actually guide me to any great extent. I read up on the subject in the library at the university. It had the telescope making books.
DeVorkin:This would be by Albert Ingalls? 
Baker:Ingallsí books or really, book, in those days.
DeVorkin:Yes, the first one.
Baker:Yes, Ď31. So I made myself a 2 l/2 inch lens —
DeVorkin:You made a lens?
Baker:Yes, to start with. I had trouble getting glass so I had to compromise. I didnít know anything about optical glass and I had to make it out of plate glass. But my first good look at the moon was with that. It was a long focal length lens, so I had it mounted on a 2 x 4 that must have been about 10 feet long. I had rather high power to start with.
DeVorkin:This was a simple lens.
Baker:A simple lens but long focus because Iíd already read about the color problems.
DeVorkin:Why didnít you make a mirror?
Baker:Well, I did. That was afterwards.
DeVorkin:Iím fascinated that the first thing you wanted to make was a lens. Can you think why?
Baker:Well, partly because I had no access to a larger piece of glass for a mirror up to that point.
DeVorkin:Was this about 1931?
Baker:Ď31, yes. Now that you remind me, I saw my first view of the moon through the telescope of a person, a transient in Louisville who was selling views of the moon through a six-inch telescope that he had mounted on a truck bed. And I saw that when I was nine years old. So that was very stimulating to me. A long time ago, but really, a first class look. I think he charged a nickel or something like that, when I was nine years old. So then, after I built the lens, I borrowed my uncleís telescope. He was willing to lend it to me. I hadnít been bold enough to ask him for it before. I set that upon a tripod, and the whole neighborhood became interested, at the place where lived, all the young people. On a clear night, in the summer at least, I would have perhaps five or six people with me. And stimulated by the interest the others had as well as my own, well, I did more reading.
DeVorkin:This was when you were already in college?
Baker:Yes. I had finished one year. So, in the time period from the summer of Ď32, it would be, I started building an eight inch telescope.
DeVorkin:This time a reflector?
Baker:This time a reflector, yes. I bought a piece of glass through the Pittsburgh Plate Glass Co. in Indianapolis. I built the eight inch, and I did that more or less alone. I discussed the problems with Dr. Moore, but he was at the university and he didnít actually look over my shoulder. I mounted it in a wooden octagonal tube, and put it on 2 inch pipe fittings. It was an alt-azimuth mount. I used that for hundreds and hundreds of hours; all through my sophomore and junior years. Every clear night that I had time, I would be out looking at the stars and Milky Way, double stars; all with my eight inch reflector. I would have kept it over the years, but unfortunately during World War II, I refigured it, as one of our exercises. It happened to be a nice piece of glass, so I just made it more accurate than it had been. But I left it on the shelf amidst a great deal of activity by 40 or 50 people, and it disappeared. I suspect it ended up as a glass tool for one of our projects. Itís too bad. I couldnít identify it further. Then, when my fatherís and motherís belongings were settled after their deaths, particularly my motherís (she died last) my sisters didnít realize the meaning of my telescope and they discarded the mountings. So that disappeared. I was up here in Cambridge. They really didnít see anything emotional about some pipe fittings and octagonal tube. It meant hundreds of youthful hours.
Baker:So I became extremely familiar with the stars early in my college career. Then we became active in the Louisville Astronomical Society. Dr. Moore was one of the principals in setting it up.
DeVorkin:You mentioned ďweĒ, does that mean that it was being set up and that you and Dr. Moore were involved?
Baker:Dr. Moore was 15 years older than I, and a professor, but there was also a fellow named Strull. Iíd known his son because Ascher was with me in the university and in high school. I think I called him Dr. Strull, he was a medical man, I believe and had a very nicely made refractor. I think it was like a four inch. On occasion, when the Astronomical Society would meet, why, he would bring it out, set it up on a tripod, and we could use it. Dr. Moore also had built a telescope, which I think was a 10 inch, and that was much better made than mine because he had a certain knowledge of machine work, and he also had a lathe and was able to nicer things with it. In fact, he made several fittings for me. So his 10 inch enabled us to do variable star work. These perhaps are out of sequence, but going down that particular line of interest in variable stars, as well as visual use, the next question of course to an active young person was, what use could be made of it? So I joined the AAVSO  by correspondence with Leon Campbell here at Harvard. So I was a member in Ď34 and Ď35. I also corresponded with Richard Prager. Maybe thatís too dignified a word. Richard Prager was certainly important in the thirties, but he was in Berlin, and in charge of the variable star catalogue, VERANDERLICHEN STERNEN and all the work that goes into that. But he was also Jewish and under extreme threat of his life from Hitler. So, itís odd how things work out. When I wrote to Prager it was as a young student writing to a great man. He was very kind and sent me free copies of the catalogues to help me.
DeVorkin:Was your primary interest in variable stars, or was it beginning to be in that direction, or were you still not thinking of specializing?
Baker:Well, most of my formal training at that time of course was in mathematics.
Baker:So I had a lot of work on that to do. In physics I was getting thermodynamics and some nuclear, just a smattering of it. It wasnít well advanced in college level, at least in Louisville in those days. But I had a lot of laboratory physics which made me quite familiar with instrumentation. We had a very good spectrometer, and so I learned all about measuring the index of refraction for materials, and prisms. We had a fairly nice small spectrograph. So I spent many an afternoon in the physics department working with the equipment. I did work with interference, interferometry, and so on. We had an elementary interferometer and I set it up for an exhibit on fringes.
DeVorkin:Were you one of the few people who was really taking an interest in such things? Were you something of a self-starter at this time, looking for things to do in physics?
Baker:I was doing extra work. Usually in the physics lab, I was by myself, just working. But that was almost true of mathematics, which was hardly a laboratory subject. Dr. Moore, for instance, wasnít able to teach celestial mechanics because the average class member wasnít the slightest bit interested. But about three of us, including my future wife, who was a mathematician too, took celestial mechanics. Dr. Moore taught it in the tutorial sense, not for credit. We just met at a prescribed time, a couple of afternoons a week, and worked through F. R. Moultonís Book On Celestial Mechanics, 1934-35. But at the same time we were working on projective geometry in formal mathematics. But then I was going fairly well beyond the average classwork in these subjects too, because I was working with point sets and integrals and things that the average student wouldnít care about at all. Unfortunately, I thought the University of Louisville in those days had an inadequate library in mathematics. I worked with every book they had, but I donít recall ever having on my own initiative asked the librarian to get any others. Many of the books were of older vintage.
DeVorkin:Was there any research in mathematics or science going on at the University of Louisville?
Baker:There was in education, not in science, unfortunately. I should say I worked in the deanís office to earn extra money, so during my freshman through junior year I was in the deanís office. This is how I know about my wifeís records, because she was a year behind me. I came across these records from the Girls High School. She was valedictorian there. I couldnít believe that she could score that high. A mere girl! [laughter]
DeVorkin:The first contact with your wife was by seeing her records?
DeVorkin:You were doing clerking work then?
Baker:Well, whatever the dean required, which included all the IQ scores and high school records brought to the university. There were projects that were financed by Rooseveltís college aid programs. We were paid 25 cents an hour for doing this — really very valuable. My wife also, my future wife, worked in the Registrarís Office, so she did a lot with keeping those records and reproducing some of the older ones that had faded and all that sort of work. But in retrospect, that wasnít too useful. But course I met my wife physically — well, I shouldnít say that — I met my wife at a football game. But I knew who she was from her high school records, from my Deanís Office work. She majored in math too, and although she was a year behind me, she very quickly caught up through summer school. We graduated together. She had a full complement of mathematics too, and she went on and took an M.A. in math.
DeVorkin:Where did she go to get the M.A.?
DeVorkin:You went to Harvard and she went to Wisconsin?
Baker:In 1934, we were taking celestial mechanics, and Iíd pretty much finished my interest up to that point in telescope making. I had my eight-inch which I was using regularly, and we used it along with Dr. Mooreís telescope for the astronomy class which he was teaching. But I was far beyond what he was teaching because Iíd read all the books in astronomy I could get my hands on. I helped him in the class too, just out of interest. I was active in all the observing parties we had including the Astronomical Society. We made a field trip to the University of Cincinnati Observatory around 1934, and I met Paul Herget. I was still quite young. I was 19. Paul was some years older and he was active at the University of Cincinnati. In fact, he has been at the University of Cincinnati all, these many years. I was very impressed to see the 16-inch telescope they had there and the smaller 9-inch. We also went to some astronomical meetings in Indianapolis, but I donít think it involved telescopes. It was just sort of a joint meeting with the Indianapolis group. So I was very active in astronomy and mathematics and physics. But I was beginning to worry about graduate school.
DeVorkin:Were you thinking at that time about astronomy?
Baker:Well, I wasnít sure what it was to be. I was very intensely working in German too, for that matter partly because my wife was of German extraction, although her parents and grandparents were born and brought up in this country. But her mother had spoken German as a child. Louisville had a rather large German community; the Germans came over just after the Civil War, principally to avoid military service. Since they were not poor they bought up a lot of land around Louisville and became truck farmers, many of them. And of course their children became not only farmers but doctors, lawyers and everything according to what their interests were. There were just two girls in my wifeís family. Her father was a truck farmer then. He was one of the deprived bright people because heíd had to quit when he was in the 8th grade. He was valedictorian of his 8th grade class. Itís incredible, all his life he could remember everything heíd studied, practically, even his graduation speech. I must say I couldnít possibly remember mine. But he encouraged his girls to go to college.
DeVorkin:So you got to know your future wife in your senior year?
Baker:No. To be specific, we met at one of our college football games in October of 1932. That would be my sophomore year and her freshman year. Then she went to full summer school sessions to catch up.
DeVorkin:Was that specifically to graduate with you?
Baker:Well, remember, these were all Depression years, and each person did all he could to get ahead as fast as possible. So I wouldnít say it was just to graduate with me, but it was to be able to begin teaching. Before she went to Wisconsin, the year she graduated from college she taught in one of the local high schools.
Baker:Yes, near her home. But she went to the University of Wisconsin the second year and got her MA there under Langer.
DeVorkin:You were talking about being concerned about graduate school. Letís follow your thought processes there; what happened?
Baker:Well, I began getting very serious about my work. Up to 1934, I simply read and learned everything I was exposed to and was interested in without narrowing my choice. I realized I would need German. I had French already. I had less Latin but that wasnít scientific anymore. But I realized when I was a sophomore that I was going to need German. When I met my future wife, she was taking German, so we agreed in the summer of Ď33 that I would spend the summer learning German, which is what I did. My wife had just completed the first year of college level German. She guided me, and then I started delving into it, using more hours during the summer then I could possibly have had during the whole year. So when fall came and I was a junior, I talked to Dr. Bredarious, who was the German teacher, (though he was of Swedish origin himself) and he of course didnít believe that I could learn German in a way that would bring me up with the rest of the class; second year German, though it was my third year. But he gave me an examination and very quickly decided I was qualified.
Baker:So I was delving into some of the thick grammars by that time, some of the back-up grammars. I was interested in the language. For the next two years, junior and senior, I was taking German, advanced German, German Literature and German poetry. So when I graduated I had quite a few accomplishments in German, because I really liked it. Graduate school was no problem at all then. In fact, one of the three requirements for the Ph.D. of course, was a reading knowledge of German, so I passed after several months after coming to Harvard.
DeVorkin:How did you make decision about going to Harvard?
Baker:After completion of my January year, in 1934 (Spring) where I was beginning to be concerned about how to go on, I decided to spend the summer working, so I applied for a job and I got it with the Louisville Land Bank. It was a bank set up by Roosevelt to get things moving again, so I was put into the accounting department, at something like $85 a month I believe it was. I saved all I could though I gave half of what I made to my family just as my sister did. They needed the money. I saved the rest of it and kept track of every penny practically and when September came, I had a scholarship at the university, which Iíd had right along, except it was given a special name. Dean Oppenheimer had to go by the rules, and so he gave me sort of an ultimatum in a way, a friendly one: I had to go fulltime to the university to accept the scholarship. But I was trying to work; I couldnít have the scholarship, although I could still go to the university. I chose to work and go to the university, because at the end of 10 months Iíd be more ahead than I would be with just the scholarship at the university itself. I had a rather peculiar senior year because I went to what classes I could go to, mainly evening classes, and my wife went to all the regular class and took notes for me, and I studied all, the textbooks that she was studying week after week in the same way as if Iíd been in class. I also had arrangements with the different professors. If I could pass the different exams along the way and the finals, I would qualify. They made this possible partly because, as I mentioned earlier, I was under two sets of requirements, and Iíd already met most of one set. So it was not so difficult. I had more than I really needed. It worked out. I kept on with my mathematics, with the physics and so on, going out to the university many evenings. It was a little bit hard, of course, to be working 40 hours a week otherwise, but I managed to do that. By the time April of the following year came, I guess in February, we had to submit applications. I applied to Harvard and to MIT and to Wisconsin.
DeVorkin:All these were in what subject?
Baker:Harvard, astronomy. MIT and Wisconsin were in math. And the appointments were made, I guess, before April 1st, so shortly after April 1, virtually in the same mail, I received all three. In a very short period of time, I guess in the time it takes to respond, I decided to come to Harvard.
DeVorkin:What swayed your decision? Or had that always been your first choice?
Baker:Well, I guess I liked astronomy, plus the fact that the math was already useful in astronomy, whereas if I continued in mathematics, astronomy would have been only a hobby. I had to make a decision.
DeVorkin:Did your future wife have any part in this decision?
Baker:Not that it was a determining one, no. Of course we discussed it, though. But no, I made the decision. Well, Harvard appealed to me, too. We had a little bit of contact. Once in a while people from different universities, including Harvard, would through Louisville and give lectures. I remember going to some of them. So we werenít excluded from other universities altogether.
DeVorkin:You werenít aware then probably that Wisconsin had Joel Stebbins and he was working in photometry?
Baker:Oh, by that time I knew many of the astronomers, from Popular Astronomy. In those days we didnít have any other journal. Popular Astronomy was the one. But I knew of Mt. Wilson. I knew some history of astronomy. Iíd read a great many books, of course, on eclipse expeditions and practical astronomy. So I knew the people. But Shapley appealed to me. Has was also in those days given quite a bit of national prominence. He frightened me, actually. That is to say, when you have someone whoís so widely known and youíre a student, you tend to put him on a high pedestal. But I also had a certain amount of initiative. I was determined to at least try my hand at Harvard. I thought they were tops in astronomy; in terms of teaching and class work and all. So I saved I guess about $1500 in the course of the more than a year that I worked. But then thatís where Bullitt came in, because Shapley didnít know that I had saved much money. He thought that I was going to come and have to be helped. Shapley had many options for raising small funds. So he had asked Bullitt to interview me. Then if he thought I was qualified, he would see if he could get his Louisville friends to raise a scholarship fund. Bullitt did this. This is when I visited his office and his home and he talked to me about astronomy and mathematics and so on. He gave me some problems in mathematics. I was supposed to solve them and bring them back the next day, which I did. Bullitt collected some of the historic books in mathematics; first editions if possible. He had a first edition of Gauss. I think only five or six copies were struck before they found a mistake and went back and corrected it. He had one of those with the mistake in it. Thatís a story in itself, because he ended up, many, many years later, giving the collection to the University of Louisville. He was well known to Garrett Birkoff here at Harvard and other people at Harvard, and there was a great tussle for a while trying to get the collection for Harvard. But the University of Louisville finally prevailed. However, the books are in good hands. So Bullitt gave me a hard time, as I would call it in the vernacular. But he had decided evidently that I was qualified, so he contacted his wealthy friends and they raised another $1500, which matched my own. So that was more moray than I needed for one year, certainly, much more, and at the same time, Shapley arranged through the university to give me a so called Townsend Scholarship for tuition for the full year. So I didnít have tuition to pay. Therefore I lived for two years from those sums, at Harvard. I think it was supposed to be $1500 minimum in those days for a person to attend the graduate school. I did rather better than that, I guess and didnít spend that much. I lived rather frugally. I was all set to come there in September of í35. Bullitt was instrumental in sending me, and I very much appreciate that. But then he called, in the middle of June of Ď35 and said that Shapley felt I should come to the Harvard Summer School. This was the first Summer School, beginning I guess around the 1st or 2nd of July.
DeVorkin:What did your family think about all this, leaving, going to Harvard?
Baker:There was no opposition. My mother was glad, actually. She was ill during those months, and when this issue of the Summer School came up, it was a bit of a hardship, because I had to leave while she was still in the hospital. But she got well all right. I kept in touch.
DeVorkin:So you went to all six weeks of the Summer School?
Baker:Right. It was an instantaneous decision. Iím just thinking of that two weeks in June, when I suddenly had to resign from the Land Bank and close out what I was doing there and get my clothes and move. It was also a shock to my future wife and myself. Weíd planned to have the summer together. So then practically overnight, toward the end of June, I came up on the Greyhound Bus to Cambridge and I believe I arrived on June 30th. I stayed overnight in the YMCA in Cambridge. The next day I came to the Observatory and met Bart Bok right away.
DeVorkin:He was the first one you saw?
Baker:First one, the very first one. He was also in charge of arrangements for the visiting people. They were coming from all over. So he had arranged for me to stay on Shepard St. in Cambridge, and thatís about the most convenient location Iíve ever had. Even now it would be convenient — itís only two blocks away. So I rented a room for the summer. It was only $3 a week, I guess. Things were on an entirely different scale. It was just an easy affair, walking back and forth, so I had maximum efficiency that way. I ate and lived at the Summer School. Everything I did was tied in with the Summer School. I mentioned over the phone that Iíd written every day about it to my fiancťe.
DeVorkin:Yes. This was the Ď35 Summer School.
Baker:Ď35 Sumner School for the entire summer. I donít think we missed a day. If we did, I may have been ill once or twice. During this first day or two, of course I was meeting everyone, all the participants. Otto Struve was here. Pannekoek was here. And Bok and of course. Cecelia Payne-Gaposchkin. Shapley Iím pretty sure was not here so much. I think he came later in the summer from France. There was a symposium in astrophysics or something going on in Paris. He was over for that.
DeVorkin:Very interesting. Iíll certainly have to check on that.
Baker:It was late r in the summer that I met him.
DeVorkin:Did you go to Struveís lectures?
Baker:Oh, I always did sit in his class. And he had me working right away. He was a no nonsense person. He had me working on the galactic rotation effect on interstellar lines in the constellation ofor ion and in fact, around the sky, for that matter. There was a great deal of material which hadnít been reduced yet that he had access to, on the Doppler motions of the very fine interstellar lines.
DeVorkin:Did he put each person to work on a particular project?
Baker:Yes. Iím not sure what the others did anymore, but yes, certainly.
DeVorkin:How many people were in the class?
Baker:Letís see, on the order of 15.
DeVorkin:So he gave each person, more or less, what would constitute an element in a research project.
Baker:Yes, those who were bona fide members who were actually registered for credit. There may have been auditors who were not affected.
DeVorkin:Were there general lectures given?
Baker:Yes, every day in the Summer School. But for any particular lecturer, it was something like three times a week or twice per week. I donít remember the details any more. I know we and Stauvo certainly worked very hard.
DeVorkin:He was quite serious about it.
Baker:Oh yes. We usually had the lectures in the mornings, and in the afternoons mutual discussions.
DeVorkin:What did Pannekoek lecture on?
Baker:Astrophysics. My awareness of astrophysics up to that time had been out of H. Dingleís book, which was the only thing we had. So I knew to some extent the elementary parts. But my first exposure, in the very first class I went to, was from Donald Menzel. In fact, the transformation was so striking, from sitting as an accountant at the Land Bank in Louisville, and two weeks later sitting in Dr. Menzelís class at Harvard, it was unbelievable.
DeVorkin:Was he lecturing on the sun at that time?
Baker:No. He started lecturing on planetary nebulae. On the transmission of radiation through gaseous nebulae. And as it turned out later I did a lot of work with him in that area. The very first lecture was on the transmission of a beam of radiation through dense fog: an atmosphere of certain opacity.
DeVorkin:How did you meet these first lectures? What was going through your mind, if you can recall? Were you excited?
Baker:Excited. Sheer pleasure.
DeVorkin:There were no gaps in your knowledge?
Baker:No. I didnít have any problem that way, because the math that was being used was not really very advanced math. It was calculus, to be sure, and analysis, but it was by no means abstruse. I was thoroughly familiar with that. Later on, Shapley was worried about me, as I mentioned. He was worried that fall when I started taking Ted (Theodore) Sterneís course in statistics.
DeVorkin:Why was he worried?
Baker:Perhaps that I didnít have the background for it. But it turned out to be no problem for me. Iíd had more math than most of the other students had had. The tutorial system at Louisville had been marvelous, even though the professors would not be considered of note. Still, they were members of the American Mathematical Society. They were good teachers and were very dedicated and interested. That, plus the books, really helped enormously. So I had no trouble with my graduate work in math.
DeVorkin:With the Ď35 Summer School, did you go to any of the Hollow Squares? Had they been organized yet?
Baker:When Shapley got back, he set them going, yes.
DeVorkin:Do you have any recollections of that?
Baker:Well, I was only an onlooker. People like Pannekoek and Shapley and Gaposchkin dominated the discussions. They were the experts. They were the ones who knew hundreds if not thousands of stars and their characteristics.
DeVorkin:Werenít graduate students sometimes called upon to review?
Baker:Oh, we were called upon for particular things. Certainly that fall and from then on, Shapley would send around his famous little yellow page handwritten notes that said, ďDo this, do thatÖĒ in preparation, ďexpect you to tell about your trip to such and such meeting,..Ē He never let us lag. If we went to an astronomical meeting, weíd come back to a Hollow Square meeting and have to report on the papers weíd heard.
DeVorkin:So he kept pretty close contact and control over the students.
DeVorkin:But you must have had your own advisor?
DeVorkin:He was graduate advisor.
Baker:He was graduate advisor to almost all of us, and I was very close to Bok. I guess all, these years Iíve been. But when I started working more in subsequent years with Dr. Menzel on astrophysics, I saw much more of Menzel than I saw of Bok, at least on a day to day basis.
DeVorkin:How did that transformation take place? Was this just the development of your own interests?
Baker:Well, Bokís interest was the Milky Way. He was, you might say, pure astronomer, interested in stellar motions, stellar magnitudes, variability, double stars and astrometry astronomy. I was too, within limits. But Bok, while he had knowledge of astrophysics, didnít want particularly to teach it. Menzel taught astrophysics. And when I first started in the fall the Summer School had set my course, because Dr. Struveís astrophysics and Pannekoek too, had thoroughly aroused my interest.
DeVorkin:That pretty much set your course.
Baker:Well, when the fall began, and we were interested in doing things apart from just classwork, why, I became heavily involved in quantum mechanics.
DeVorkin:This involvement in quantum mechanics, was that directly from Menzelís work?
Baker:Yes. Menzel gave an excellent class in astrophysics in which quantum mechanics played an important role.
DeVorkin:You didnít learn your quantum mechanics then from physicists at Harvard?
Baker:Oh, but I did, because in addition to Menzel class, I went over to hear E. Breit Wilsonís class in quantum mechanics. He was in the chemistry department, still is and has been always a Harvard professor.
DeVorkin:This was in the summer?
Baker:No, this was in the fail. The Summer School was Summer School pure and simple and 100 percent activity. On the other hand, I was a very junior member. People like Goldberg and Greenstein had already been there a year or two. And so they were the seasoned graduate students, you might say, and they had their land legs. Everything to me was brand new and fresh and so I did everything and anything that was involved with the Observatory. We observed Nova Herculis, for instance which took place that year. In fact it was Nova Herculis which had aroused my interest in 1934.Thatís when it first was found. By the time 1935 came along, it was much fainter but still quite visible through our 12 inch telescope here. It was not a visual nova any more. So in the Summer School, and when there was observing to be done, I would come up to the 12-inch and observe the magnitudes of Nova Herculis with Leon Campbell. Thatís an offshoot of the AASO work. So I got very familiar with the use of the 12-inch, which had a photometer on it. We also had various social gatherings in the evenings; I guess maybe every second evening at The Summer School. That was a novel experience to me, because from the Depression years, there had been no social life at Louisville even in the university, except through the clubs. I be longed to the Math Club there and we had our meetings, but The Summer School was much better for that because we had all the people here for a specific purpose during the summer, of an evening getting together, meeting together, picnicking, going out to what was called Oak Ridge in those days, itís called Agassiz now. It was generally easy to relax in a nice way. I remember Gilbert and Sullivan songs were very popular, and some of the graduate student members from this area were very good at it. I really hadnít finished some of that part of my Louisville training, because we did have clubs and I did share in some of those activities. I mentioned the Astronomical Society but we also had a math club. We also had a German club. I was very active in those organizations. We had picnics up the river, for instance, in the spring. It was all what you would expect of a normal student life. But in the Summer School here, it was on a serious level. All the classwork was. I worked hard and it did me an awful lot of good. It ended on about the 10th of August with a picnic the next day down at Marsh field or at Cohasset, which was a novel experience. I hadnít even seen the ocean up to that point. It was a beautiful day like today, sunny and cool, with ocean breezes, and having the astronomers all frolicking around and swimming and picnicking and playing soft ball and having small sailboats go by, and seeing the meandering streams was very idyllic.
DeVorkin:Yes. Did the astronomers continue to talk astronomy even at these times?
Baker:Oh, always. Always shop talk everywhere. In fact, I was the most guilty member, I guess. Florence Menzel used to scold Don and me for talking shop at all these gatherings. No matter where we were, weíd get off and start talking about nebulae and things.
DeVorkin:So you did find that you were talking with Menzel a lot?
Baker:Certainly, as the years went on. Oh yes. That was excellent. Don was excellent to students that way. He gave of himself. He never minded lecturing. I always marveled at how willing he was to do that. You could get him to give a lecture any time. His astrophysics of course was deep in his own experience. He was probably one of the great astrophysicists. So it was a privilege to work with him.
DeVorkin:Did you find that the Summer School experience, bringing all the astronomers together produced any particularly exciting or new ideas? Maybe not in the first summer but in later summers?
Baker:Oh, Iím sure of it, although I wasnít exposed to everything as were Greenstein and Goldberg who were there far longer than I and who perhaps were more aware of science in the practical sense. I had come straight from a text bookish type of college, you now, and did not have practice or practical experience. In my senior year at the university Iíd calculated the orbit of Venus out of observations recorded in the Almanac, just to prove I could. That is to say, knowing the positions, I got the orbit. That was just a workout. But I was interested to that extent in orbit theory and so I spent a lot of time on it. That was an outgrowth of celestial mechanics, of course. But now here at Harvard, that fall, we had Menzelís courses in astrophysics and Sterneís in statistics and Bokís on the Milky Way, and Cecelia (Payne-Gaposchkin ) lectured on variable stars, and Fred Whipple on photography. And also I was doing quite a bit of photographic work here. I hadnít done any before. Iíd never been exposed to it. Even in the Summer School, one of the first things I was asked to do in the 1936 summer sessions was to make some prints in the photographic lab of Menzelís AK-BULAK eclipse pictures, which I did.
DeVorkin:It looks as though you obtained an M.A. from Harvard within one year.
Baker:I did, yes.
DeVorkin:Was that standard?
Baker:Yes. Harvard had very minor requirements for an M.A. You had to have a reading knowledge of a language, and an elementary language in another, say of chosen languages, primarily German and French. Completing four courses satisfactorily through the year was sufficient. A Masterís thesis was not required, but evidence of successful individual independent original work had to be shown. But that was vouched for by the professors. So all through that year I was working on variable starts with Bart Bok and making magnitude measurements and doing calculations on hydrogen nebulae with Dr. Menzel.
DeVorkin:You started that in í35 and í36?
Baker:The elementary aspects of it, right. I was getting quantum mechanics fairly well understood. Of course I never really went into the more complicated atoms and molecules. The nebular work we did was either on ionized gases or hydrogen. Later on the series that I worked with did include the higher and more complicated atoms, but my own work in that area sopped around 1940.
DeVorkin:Were you aware in 1936 that Menzel was just beginning his long series of papers? Was he actually talking to you and to others about planning out this whole series of papers?
Baker:I think he was but he was talking more with Goldberg. They were closer on that, than he was with me. I think I began that work around í37.
DeVorkin:Your first paper was in í36 and that was ďNote on Equivalent Breadths of Absorption Lines.Ē 
Baker:Oh, that was something else.
DeVorkin:It was not directly on nebulae, but you reference Menzel all over the place here, and I know you were very much in touch with him.
Baker:Thatís right, Menzel had us working on equivalent widths in the solar atmosphere, Goldberg principally, but I got interested in it. Of course he was giving us this material in his classes in astrophysics. Also Menzel was writing a book in astrophysics, and itís a terrible shame that he didnít finish it.
DeVorkin:Oh, I didnít realize that.
Baker:Yes, he was. He had written a number of chapters, and he had these chapters on the table in the tutorial library. The books in the tutorial library in those days were not to be taken out. They were painted with an aluminum stripe and kept on the shelves, and any materials put on the tutorial room table were not to be taken away. So anything the professors wanted the students to have access to, that they could spare, they put on the tables.
Baker:This included chapters from Menzelís book.
DeVorkin:Was the manuscript saved.
Baker:Possibly. I must say it was never printed, but Goldberg might have an idea of where it might be, or Florence might. Itís unfortunate. I think he had the feeling that it needed a little more modernizing, a little more work in some areas.
DeVorkin:Yes. I wonder if that had any effect on Lawrence Aller later on. Aller produced a number of books in astrophysics.
Baker:Well, Aller had access to Menzelís manuscripts, but of course he had his own interest and hard work and intelligence and everything else. So when Lawrence wrote his book that was Lawrence pure and simple. He has had thorough roots in the subject. He had full exposure to Don all through his years here, and of course, Lawrence and I and Don and Goldberg all worked in the series up to 1940, Ď41, I guess, on the nebular papers. Now, the equivalent width paper was on the effects in the solar atmosphere. I had an idea that the separate integrator that Don in his work from Lick Observatory had employed could be brought together, at least mathematically, though the regions in between were physically hard to treat. This is what I did with the equivalent width formula.
DeVorkin:It certainly indicated your direction of interest at that time.
Baker:Yes, it did. Somehow, I had begun thinking about thesis work already in Ď37, when I was beginning to work on the hydrogen nebulae with Don.
DeVorkin:You were working on the theory of the Balmer decrement.
Baker:Right. The first paper was probably six months to a year after we started working.
DeVorkin:ApJ 86 (1932) pages 70-76.
Baker:Right, so that means we were probably working on it in later Ď36. Oh, another factor, I mustnít forget this. Don taught the elementary astronomy class at Radcliffe and I was his assistant in Ď36 to í37. So I was working with Don for that reason very closely. I took care of all the lab work: the night observing, setting up the small cameras and taking star plates — all those things.
DeVorkin:You were pretty busy.
Baker:In Ď37. These are little scraps of information that come to me now. Shapley used to have what he called Sunday night observing and the graduate students had to take turns assisting. So we all did a stint. We had a paid observer who lived in Cambridge and came up to the Hill and worked every clear night. But on Sunday nights, when the paid observer was taking his night off, the students took over. So I got familiar with taking plates with all the cameras in the yard. I kept the records and did the same thing the paid observer would do, but did it on Sunday nights. And those were often cold nights in the winter of Ď35 and Ď36. I remember I really didnít have warm enough clothes for it. But I also had a problem of getting to my math class on Mondays. I was taking not only Sterneís statistics but I didnít want to give up formal math, so I took a yearís course at the math department in Sever Hall with the same Dr. Rudolph Olanger who was at Wisconsin, but he was visiting that year at Harvard. He taught the course in complex variables and analysis in Ď35 and Ď36. So I took the full year, and I didnít do as well as I would have if Iíd been in the math department, because we had so many activities in astronomy. It was very hard to stay up all night and go to an 8 oíclock class, which we did.
DeVorkin:Thatís right. Yes.
Baker:I often wished I could 1we given it more attention. But I did all right. I read a good deal and I got a B in the course, against the regular mathematicians. But it was additional to everything I was doing in astronomy. Iíve never regretted it personally, being able to carry on with math. Langer was a very good teacher. The following year he taught my fiancťe at Wisconsin.
DeVorkin:She was your fiancťe through these two years when you were separated?
Baker:We became engaged right after the Harvard Summer School. I guess it was early September.
DeVorkin:So through Ď37 you also began working with other people in the Menzel group; Shortley was involved?
Baker:Shortley came later for me, although Don knew him well. He was at Ohio State.
Baker:Don was out there many time s, and Shortley would visit Don. But it did not involve me, although later, I guess around 1940, I worked with Shortley and Don together on some aspects of the LS coupling, I recall. It was transitional regions between what we called LS and JJ coupling where there was an awful lot of calculation to be done and it was very primitive. We didnít have calculators, so when anyone mentioned calculating quantum mechanical things, it usually meant a monthís hard work, not just an evening.
DeVorkin:During these early Summer Schools, Ď35, Ď36, even Ď37, Henry Norris Russell showed up.
Baker:Oh, Russell was here, yes. He certainly was.
DeVorkin:Since you were doing this sort of work that was not too far from his interests, and of course Menzel had been his student, did you have any contact with Russell?
Baker:I had very little with Russell. Russell and Goldberg worked closely together whenever Russell showed up. Russell was beginning to fade. Along around 1940, he began to have a nervous twitch in his head and all. But otherwise, he was no worse than anybody else at a given age. Russell was brilliant, no question about it, and he knew astronomy from A to Z, so far as it could be known in those days. He was Shapleyís teacher. In fact, Russell was a man of many things, but he taught and did all his original work in double star astronomy which got Shapley off to his start the same way in eclipsing binaries particularly.
DeVorkin:You yourself had no direct contact with him?
Baker:But I myself, with Russell, only heard his lectures every time he came, or when he would literally dominate the Hollow Squares when he was present because he knew everything.
DeVorkin:Was that sort of a nice type of dominance, or was it something that was stifling to some people? Did he treat some people roughly?
Baker:Well, I can say that if somebody happened to be wrong about something, he might be embarrassed. But I donít think Russell was a caustic individual. He would simply tell you what the facts were.
DeVorkin:So he was very constructive?
Baker:Oh sure. There might have been occasions when somebody else might have crossed swords with him, on some astrophysical point, but not that I know of. No, I always felt that Russell was an extremely able scholar. But now there was another event of considerable importance at the time, and that was the Tercentenaries about Ď36.
Baker:Because it wasnít only Russell, by any means, but great men from abroad came. Eddington was here and Einstein and Levi-Civita and probably others that Iíve forgotten.
DeVorkin:Chandrasekhar came. And Saha came.
Baker:Yes. In fact, Chandra came during that winter and Kuiper too.
Baker:Yes. Not in Ď35 but in Ď36, I believe. Youíll have to check the dates, my memory fails me, but it seems to me Kuiper was here already in that Ď35, Ď36 winter season.
DeVorkin:Yes, but not during the summer.
Baker:I donít recall it. I donít think he was in the first summer. I would remember that. Kuiper was always very active. If heíd been here in the first Sumner Session, Iím sure I would remember that. He was here in the second one. He worked through, and so did Chandrasekhar and Chandra went on to Yerkes.
Baker:He and, so did Kuiper. But Menzel and Chandrasekhar unfortunately didnít hit it off too well together. Iíve always regretted that. It started when Chandra had done some theoretical work on sunspots in which he had been too formal in his mathematics. He had made models of sunspot activity which werenít what Menzel thought they should be in terms of what you actually observe.
DeVorkin:Was this during the year or at the Summer School?
Baker:I think it was in the summer. Iím not sure whether it was in the Summer School. But Chandra gave a colloquium and Menzel disagreed with many of the results. And the two men never hit it off after that. It was just one of these things. But Menzel was closer to observations, very close to observations, because he had made them himself.
Baker:In fact, there is a separate long story on the eclipse expeditions. Menzelís whole life was one of eclipse expeditions. Heíd been on the í32 eclipse from Lick Observatory Maine, and had great success. In fact, all his mature life he was still having the eclipse pictures of 1932 reduced. They were excellent, in focus, and just a large quantity. Goldberg spent a lot of time on it. But one of the things that colored my own student life was Menzelís expedition to AK-BULAK in Russia. I donít remember the date of the eclipse any more, but it was in í36. All through the winter and spring of Ď35 and Ď36, Menzel was getting his equipment ready for this expedition to Russia. And so I worked on this equipment. Itís probably one of the reasons that I went into optics afterwards, I guess. Whatever I did, I gave it all the time I could give it.
DeVorkin:Do you feel that was your entry into optics?
Baker:Well, you can trace it back. In high school I already had a lot of practical experience; nothing in college of consequence beyond the telescope making. But when the eclipse expedition began, then I had a certain amount of awareness of metal parts and machine work and drawing, and I made all sorts of mechanical drawings. So I went to MIT in afternoons by bicycle and worked with the eclipse expedition along with several of the other students.
Baker:It was set up at MIT where they had room. Most places around Harvard didnít have shops suitable to what Menzel was trying to do. Also his work was tied in with Joe Boyce, who was a physicist a t MIT, and with George Harrison at MIT. In fact, by that time, we worked so closely that going to MIT was second nature to me even in my first year.
DeVorkin:This first year was Ď35, then?
Baker:Ď35 and Ď36. I got myself a bicycle. I was down there many a time at the spectroscopic laboratories working with Henry Hemindinger, focusing and checking out drives. The actual work that mattered was done by MIT machine people, machinists. But Joe Boyce was prominent in directing it. Menzel of course came down and helped. And so I did work with spectrographs, and I checked out one Bausch and Lomb spectrograph here at the Observatory, a UV spectrograph. You can see that I was beginning to be in optics. At the same time, we were building re spectrograph for stellar astronomy at Agassiz. I remember going to the physics department at Harvard in í36 or 37í and borrowing a spectrometer, working there with it, to measure the UV prisms for our spectrograph. I had to find out what their qualities and characteristics were.
DeVorkin:Were you making any conscious decisions at this time; to do work in optics?
Baker:No. It never occurred to me that I would be actually in optics. Iíd always enjoyed it through my telescope making, and I went to all the telescope making club meetings. The Boston Club met every Thursday night, I guess. They certainly do now. I think that was true then.
DeVorkin:Did they meet at the Observatory here?
Baker:Yes. Once a month but Thursday nights weíre also the nights that they met down in the shop. They had a basement optical shop.
Baker:Here in Building A it was called, which is the old wooden building. They still call the building thatís in the same spot Building A. Itís a brick building now. But If you look at the old photographs of Harvard, there was a wooden structure where Leon Campbellís old office was. In the basement, virtually unfinished, were all the benches and polishing instruments and machines that the amateurs had put together. So I was familiar with their work down in the basement of Building A. All these different things were coming together, because my work in astrophysics brought me into a thesis subject. I planned to do equivalent widths of stellar spectra as my thesis, and the UV spectrograph that had been built already from Germany oddly was really an unsatisfactory instrument.
DeVorkin:Was this Hilger?
Baker:No, we had a small one called the Hilger afterwards. This was called a Heinrich spectrograph. And that was the local machinist actually who made the metal parts. But the ultraviolet optics were made in Germany at the Halle Company. Named after the town Halle, I think. Why they were unsatisfactory, just how that happened, would be a separate research problem. It may have been from inadequate ordering or specification.
DeVorkin:I take it your Ph.D. thesis then was not in astrophysics per se?
Baker:It turned out to be in several things. Iíll explain why.
DeVorkin:So you were going to explain the elements of your thesis.
Baker:Well, Iíd better build up to it a little bit if we have time.
Baker:It wasnít quite so clear cut as all that. When I discovered that the Halle optics were inadequate, it was my first experience with spherical aberration. Iíd read about it and Whipple lectured to us about it.
DeVorkin:Now, this was when?
Baker:In the spring of í37.
DeVorkin:Youíd not yet heard of Schmidt?
Baker:Oh yes, we knew about that in Ď35 because it was all the rage then. Oh yes, people had already started talking, and Theodore Dunham was extremely interested in Schmidts as early as í34, I guess.
DeVorkin:Right. Weíll get back to that.
Baker:It was a well-known thing. But Whipple lectured about it and its optical properties already in his course, along with photography, and heíd also lectured in the spring once on the theory of optics, including a mathematical treatment. But it was in that late spring of Ď37 that, since the spectrograph was taking very poor spectra, Whipple suggested I might like to find out why. And so I took it apart and took the prisms down as I mentioned and found out their surface quality was marginally alright. They certainly transmitted. The Schott glass was ok. But the thing that kept the instrument from working was that the optics had been designed with a collimator that had spherical aberration beyond anything that could be acceptable. Just why it was made that way I donít know. It might have been confusion in the requirements, or it may have been that the Germans of the day were not terribly worried about Americans. In any case it wasnít satisfactory. It may be that they had planned to do some aspheric figuring to make it satisfactory and then found out that we wanted delivery. I donít know the story. Anyway, I measured it and somewhere in my notes I still have those measurements. I found out it wasnít satisfactory. I wanted to do high dispersion work. The Heinrich spectrograph was a two prism UV spectrograph that had a dispersion of about 30 angstroms to the millimeter. Too small to be effective on equivalent widths of most spectral lines. My memory has come back again, and this verifies that Shapley was in France during the first Summer School. When he came back from France that summer late in the Summer School of Ď35, he brought with him what he called the Tremblot spectrograms of Beta Lyrae. There was a French astronomer, probably quite analogous to myself, who had built a spectrograph and used it principally in Ď34 and Ď35 observing spectra in the UV principally of Beta Lyrae in all its phases of its binary period. So there was something like 40 very nice homogeneous spectra, which he gave to Shapley to have somebody at the Observatory work on and Shapley when he got back said it would be a nice thing for me to work on. So I worked on that during Ď35 and Ď36. You can see I was busy.
Baker:Also when Shapley got back, I had a period of about five weeks after the Summer School when I didnít feel it was worthwhile to go back to Louisville, and Shapley thought I should stay here and work at the Observatory, and I thought so too. I started out in a scholarly way, so to speak. I holed up in my room with half a dozen math books and physics books and spent I guess three or four weeks in intensive study to carry along in an advanced way in those subjects. But then William Calder here at the Observatory was trying to measure the magnitude of the sun, which is no mean feat because he was doing it photo electrically, and photoelectric photometry was just beginning to be appreciated. And Shapley was in the forefront of it; Calder was doing the earliest photometry here.
DeVorkin:Shapley was excited with it but delegated it to someone like Calder?
Baker:Calder was qualified. Calder was head of Agassiz or the station manager, you might say, at Oak Ridge, a member of the staff. So his job was not only to get the instruments going properly, but also to fit but the big 60-inch reflector with a photometer. He was handicapped because to save money apparently the secondary of the 60-inch, which was installed in 1935, was figured as a sphere, just temporarily. It was a convex Cassegrain. But it didnít give him any kind of decent star image. Now, the primary was paraboloidal and the Newtonian focus was fine. Thatís where the Spectrograph was to be.
DeVorkin:What I see here is that there were many, many optical projects to do, and you sort of gravitated to them.
Baker:Some of them. For instance, Goldberg was assigned the early work on the Heinrich Spectrograph. And he was out at Agassiz and I know Pannekoek was out there with him on several occasions using the Heinrich on the telescope, even in the summer of the first Summer School. Goldberg himself can tell you far better than I as to all those events, because Menzel had rented a cottage out there. Florence and Don lived there and entertained other people including Goldberg and the Pannekoeks and Struve and all that. They had many parties that I wasnít part of. Goldberg would be glad to tell, you all those things. But he and Goldberg worked with the Heinrich on the 61-inch, among other things. The fact that it wasnít successful was why it was put aside, till a year and a half later when I started working on it, almost two years later. I remember being up in the hall in the wee hours of the morning, working with the monochromator that I rigged up to get different wave lengths accurately; especially from the ultraviolet to the visual. And I measured the characteristics of both the camera and the collimator part of the spectrograph, and made very careful reductions. So all of that was of interest to me, and I hadnít up to that point undertaken any calculations, though, in optics. I just primarily did observing the deficiencies of the equipment.
DeVorkin:Doing everything in the laboratory?
Baker:In the laboratory. But then an important event was my becoming a junior fellow, because after the first two years, when my own funds and Bullittís assistance had ended, I worked the summer of 1936 for Bart Bok part time on objective prism radial velocities. Bart had been very, very interested in quantity production of radical velocities, and regrettably, looking back on it, he simply did not have adequate equipment. But it was not obvious to anybody. We had the 16- inch Metcalf which is still out at Agassiz, and Bok had a pair of 16-inch prisms that would go over the upper end of it to get spectra over the whole field of view. He had a photometer built, and a comparator for measuring radial velocities of rather fuzzy, you might say, spectra. And I was one of his assistants during the summer, I think there were several measuring hundreds and hundreds of stars for radial velocities, and Bok and other assistants did the statistical reductions to get radial velocities.
DeVorkin:How did you get radial velocities off an objective prism?
Baker:He had a Europium cell.
Baker:The Europium lines were filtered out of the stellar spectra. Wherever these appeared on the plates, we had reference lines. The comparator would invert and compare the same spectrum, one right side up, the other opposite. So when the lines were coincident Ė the Europium line and the particular spectral line, the comparator would be read for the displacement. Bok was able to prove that he got significant radial velocities. But as the stars got fainter on the plate, the errors increased to the point where they ceased to be very useful. Years afterwards, when I took a more professional look at the equipment he was using, I was dismayed to see how poor it really was. The upper edge of the prism, for instance, one of them, was only a quarter-inch thick, and it was so full of non-planal fringes that spectra were poor for that reason alone, apart from seeing and other things. But he just simply didnít have access to first rate equipment. A great deal of good work was damaged because of that.
DeVorkin:Thatís too bad. Anyway you were working with Bok on that?
Baker:Yes, during the summer of Ď36, and had many, many discussions on it.
DeVorkin:Did he nominate you for the society of fellows?
Baker:I think Menzel did; Menzel and Shapley together. But I donít really know. I suppose the staff did. In any case, I was a candidate, and that included being interviewed by the senior fellows, which was a rather formidable affair for a young fellow. I was 22, I guess. It was in Ď37 so I would have been 22, yes. So to meet A. Lawrence Lowell with his great moustache and his scholarly mien — his importance and general greatness — and all the other senior fellows, A. Lawrence Henderson, John Lowes, Professor Birkoff particularly, in mathematics, not Garrett but his father. They were all very formidable. But I was made a junior fellow and it began, I guess, in September of Ď37. From then on, I didnít really have any hardships because I was supported by the Society. We didnít know at the time, it was known of course to some people, but A. Lawrence Lowell had given his private funds to set up the endowment for the Society of Fellows. This was back earlier, somewhere around 1934, I guess, and so this is all well-established now. I donít know the exact details, but the income from it, even during the Depression years, was ample, and so the junior fellows were given stipends I believe of $1250 for an unmarried student, for a three year appointment. There was possibility of being re-nominated for a second term. But it turned out I was a junior fellow for five years, three years the first time, and I would have been another three for the second except for the war. It was in Ď42 that I stopped being a junior fellow and went on to full time war work.
DeVorkin:So that was your basic support.
Baker:It was my support, and it was an order of magnitude more liberal than anything Iíd been used to. The idea of having the Harvard houses, living in a dormitory, all expenses paid, with research money — perhaps the shock was too great. In any case, I donít think the junior fellows were unappreciative. It was a very good and in fact an invaluable experience for us all. We had lunch every Tuesday and Friday together, at the Harvard Elliot House, where the junior fellows had rooms and every Monday night during the regular year, we had formal meeting, with all the senior fellows present. Weíd have wine generally, not cocktails but wine before dinner, and then a common table dinner I guess in the Cambridge, England style, followed by a full evening of discussion with the senior fellows and with visiting people invited by various senior fellows.
DeVorkin:During this period, you got married in 1938.
DeVorkin:Was that partly because you were now supported by the Society of Fellows and you felt that you could get married.
Baker:It was perhaps that, but weíd planned to get married in Ď37, and Shap1ey suggested I wasnít quite ready for it, since I had no visible means of support. So we postponed our wedding for six months for that reason without any great consequence over the years, but we waited then until I was a junior fellow. There was an interesting sidelight to that. Shapley was of the opinion that getting married was something that belied oneís interest in pure scholarship. That is to say, things were very serious in those days. So he suggested that if I got married too soon, it would cause the senior fellows to think I was not frivolous but somewhat less than thoroughly dedicated.
Baker:But I wasnít alone. As it turned out, Shapley was not fully informed. E. Breit Wilson who preceded me by two years had had this very problem. The story is this. When E. Breit Wilson, who was at Cal Tech, received word that he had been offered a junior fellowship he sent back a telegram saying, ďThis is very fine, but will it be possible for me to get married?Ē This caused some consternation among the senior fellows — the first time the issue had come up. So they decided in their discussions that yes, this would be satisfactory, so they sent back the acceptance, ďYes, itís possible. You can get married and we will increase the stipend accordingly. We know you will not be able to live among Ďthe Harvard houses. You will be married and so you will have extra expenses, and so married peopleís income will be increased to $2250 a year.Ē But when Breit Wilson showed up in Cambridge, he was met by several of the senior fellows and they said, ďWhereís your wife?Ē He said, ďOh, I donít have a wife. I just wanted to know if I could get married if I found one.Ē (laughter) The whole issue had been debated on a non-existent wife. When my turn came, my way had been completely paved, not only by E. Breit Wilson but also by Ivan Getting. Heís a very important person, still is. Ivan was a Rhodes Scholar and I believe he was a winner of the Edison contest back in the thirties, a very important nationwide contest. He came to MIT as an Edison scholarship winner, and had his full engineering career at MIT. I should say that he was an Edison scholar in his undergraduate work. As a Rhodes Scholar, he went to Oxford and spent two years and got his Ph.D. at Oxford. He was to come back to the Observatory and be here the fall that I was there.
DeVorkin:Is that I. A. Getting?
Baker:Thatís right. Weíre very close friends. His career is more interesting by far than mine. In any case weíve been friends; I say I saw him only a month or so ago. But Shapley told me when he first met me in 1935: ďYouíre going to have some pretty stiff competition this fall with this fellow from Oxford coming, I. A. Getting. Youíve got to really get to work, you know.Ē It turned out when Getting came; of course he was a very affable person in every way. But Ivan talked at great length with Dr. Menzel, and decided that his own personal interests were more likely to be in physics than in astrophysics. So he went over to the physics department. He stayed there and became a junior fellow I think a year before, but youíd have to check on the date. He was very important to me because we lived in the same apartment house when I first got married, and we got to know him very well. So off and on all our lives weíve been together. So now, Ivan was in physics. He was in the junior fellows and very active in the junior fellows work. And he was very interested in the gathering clouds of the war because his father had been important in the setting up of the Czechoslovak nation after World War I. And his roots were deep in the history of Czechoslovakia. Still are. Being of Czech descent heís always interested in their welfare and deplores the course of history there, first Hitler and then Communism, terrible. But in any case, war clouds began to form in Ď39, Ď40, and the junior follows had intense discussions about all phases of it. We of course had our historians among the junior fellows, and it was a very lively group, certainly lively.
DeVorkin:What were your feelings about participation in the war?
Baker:Well, itís a hard question to answer when put it that way. We were all loyal certainly. We werenít at all sure that we were going to be in a war, but it looked that way, and then we didnít know Rooseveltís intentions of course. And Roosevelt himself, in running for office in 1940, had said he was going to keep us out of war and all that. We had the problem of registering for the draft, so in 1940 we all had to go down to Sever Hall or somewhere, I forget where, and sign up to get draft cards, which we did. Of course there was a great deal of opposition around the country, and the cry among the young men was ďOver the hill in October,Ē you know. They marched around with wooden sticks instead of guns. They didnít have any to speak of. At Harvard the discussions were much more erudite than that. We had visitors in nuclear physics. We knew at an early date about fission. In fact we knew about that almost as early as anybody. Itís a separate story perhaps so letís go back to Munich a little bit. Through Shapleyís help, my wife and I went to the International Astronomical Union meeting in the summer of 1938.
DeVorkin:That was in Stockholm.
Baker:In Stockholm in late August. In a way it was our delayed honeymoon, because Shapley in some way kindly provided the wherewithal for my wifeís expenses and I was sent by the Society. Not that we lived it up, so to speak. We lived the cheapest way we could. So we went with the Shapleyís on a steamer called the Europa, as I recall, going across first to Bremerhoffen and then by boat train across to Stockholm. We were closely associated the whole way with Shapley and his family. It was a very marvelous experience, to have this sort of contact. So then Stockholm itself for a week was pure astronomy. We had an international gathering, met many people with whom weíve been friends ever since, and it was perhaps marred only by some construction work that went on the whole week and beyond at the meeting place. That made it a little bit noisy. But other than that, we all had a wonderful time. Many anecdotes could be told about that. But it would take a lot of time to tell them.
DeVorkin:Was there anything on solar energy, any discussion?
Baker:Not in my group. Not solar energy.
DeVorkin:What about the possibility of the use of fission in the war?
Baker:I was building up to that in a way, because this was the summer of Ď38. The German warships were in the harbor at Stockholm and Goering was visiting. The Swedes were neutral but they had a slight tilt toward the Germans, because of proximity. They supplied a great deal of iron ore and timber but officially they were neutral. But after the meetings were over, my wife and I had three more weeks, maybe longer, five weeks. We went on a roundabout tour through Norway, down to England; attended some functions at Cambridge, England. Went across to Holland, and then spent three weeks in Germany visiting all the observatories. We visited the Hamburg Observatory, saw Schmidtís grave, and saw the Schmidt telescope they had there. He built the first two really.
Baker:We went to Berlin-Bergdorff. Then we went to Berlin-Bablesberg and saw the Einstein Turm and by this time I guess Prager was getting ready to leave because he was in danger of being executed.
DeVorkin:What were you leading up to here?
Baker:Oh, just the fact that we spent the three weeks in Germany at the time leading up to the Nuremberg grand Nazi Party days, which we attended. Thatís a separate story, that is to say, we werenít fully aware of what the whole thing was. We were just 23 years old. But we attended, and were a little bit frightened by the military aspects and the jackboots and the marching military songs and the motorcycles and so on. All militaristic. Then we went on to Munich and more pleasant things, the Science Museum there, and then on to Stuttgart and back to the border at Aix des Shappelles-Aachen, just on the day of Gottesberg. We left Germany when Chamberlain and Hitler and Mussolini were having a meeting, and around our train were troop trains the Germans wanting obviously to be seen, thousands of military men in uniform and cannons and so on, enough to make it seem really genuine. So my wife and I left and went into Belgium, then France. All we had were our prearranged tickets and probably $20 so I donít know what would have happened if war had broken out. But in any case, our tickets were on a German boat, the HANSE coming back from Cherbourg , after about a week in Paris. Oddly we got sick in Paris. That wasnít a pleasant time, unfortunately. So we showed up for the boat train, met the HANSE and we were in doubt the whole time as to whether the HANSE would ever come, because of Gottesberg. But it did come, and then we were all right all the way across the Atlantic to New York. But two days out of New York, the hurricane of 1938 occurred, and the ocean waves were mountainous. We were sick, you might say.
DeVorkin:You started talking about this when we talked about fission.
Baker:Yes. Iím coming to it. Apart from hurricane difficulties getting back and general damage everywhere, why, it was at the first meeting of the Society of Fellows on my return that we started talking about atomic fission, at least (first) that I was that aware of. The work that had been done in Germany had finally reached the ears of physicists all around, and then the meaning of it in terms of an atomic bomb was self-evident to the Harvard physicists. There wasnít any doubt about the fission, if it had certain characteristics that an atomic bomb was possible, and these young men were sitting around the lunch table discussing this. Iím sure we heard about it before Roosevelt did. At least itís likely, because it happened. Lisa Meitner I guess told Niels Bohr, Niels Bohr had brought it to this country. And it spread very rapidly.
DeVorkin:You had no contact with it when you were in Germany?
Baker:None. No. Well, I did have contacts with astronomical optics there.
DeVorkin:Letís talk about that. You met Konig?
Baker:Yes, In Jena. We had lunch together. He had me drinking Rhine wine, white wine for the first time in my life. Iím afraid I babbled more than I should have, in terms of the Schmidts and everything I knew about them, but it was harmless, in a way.
DeVorkin:Was there anything in that trip that got you more interested in optics?
Baker:Well, this was in the summer and fall of Ď38. I have to retrace my steps a little bit, because after the spectrograph episode, where the Heinrich was no longer adequate or satisfactory for thesis material, I decided that it would be worthwhile if I would build a spectrograph and observe with it as part of my graduate plans. I did. I spent a great deal of time on it. First of all, I became knowledgeable about grating spectrographs. I wanted it to be a grating rather than a prism instrument. I made visits to Baltimore, met R.W. Wood, and worked with Dean Harrison and R.W. Wood on getting suitable gratings.
DeVorkin:So you did have contact with Harrison directly.
DeVorkin:Because this will be important when we start talking about the war, I imagine.
Baker:Oh yes. Iíd already been working with him ever since the eclipse days of AK-Bulak. Iíd met him in the lab on many occasions. Oh yes, George and I, ďI should say GeorgeĒ later on when I got to know him much better, knew he was doing this fine work in the automatic reduction of high dispersion spectra, carrying it to all the energy levels. In this period of time, I was interested in getting a grating spectrograph built, so I borrowed a grating from R.W. Wood and built a grating mount for it and put it piggyback on one of our telescopes here in the yard. And you can see how my different earlier experiences also fit into this. I began taking spectra of the Pleiades. I was extremely pleased because even with the small grating I was able to get about a dozen of the Pleiades stars in the ultraviolet. This was very encouraging, so I applied to the Society of Fellows for enough money to build the spectrograph, and I got intrigued with the idea of a special collimator. It was a Wadsworth-type mount that I was interested in, and this was used of course in several different places to get point focused spectra. The spectra itself are kind of a streak, but the Wadsworth mount is capable of giving a sharply focused, anastigmatic spectrum. The only thing was, it required a concave grating. I had the blank made by one of the amateurs and checked it out to make sure it was good enough, and then took it down to R.W. Wood for ruling on the Rowland engine. It was 3 x 6 inches. I was disturbed that I was going to lose about a magnitude of light, by the fact that it wasnít a square grating. So I devised cylindrical parabolic mirrors to be used for the collimator, which turned out in later years to be related to similar things for x-ray telescopes. In those balmy days I was primarily interested in using the cylinders to get an elliptical image from a circular telescope, which I did. But the optics required a lot of careful non-spherical figuring. So I had to build equipment to polish these mirrors, which I did. It took a lot of student time unfortunately. But, around1940 it was complete and I worked out at Agassiz on the 61-inch. It was called Oak Ridge still. I had the spectrograph tied to the 61-inch telescope, and observed on many a night in the winter of Ď39 and Ď40, first checking out the instrument and then getting spectra of different stars. I also did some work in the infrared, which was fairly normal in those days. That was all about in the same time frame. But the war clouds were forming, and we had already registered for the draft. So in 1940 I was beginning to wonder; the war looked as if it was coming as to what I should be doing. By this time, I had gone through optical textbooks. Iíd built my telescopes and these cylindrical mirrors, and was thoroughly aware of photography and optics and while I had in mind working with the spectra of stars, I actually was fairly knowledgeable about the equipment already. Then in the spring of Ď37 I started working on my own theory of optics, to see if I couldnít design an apochromatic refractor, which I did. It was built by Leon Barnes, who was still working at the old Alan Clark Co. I have no idea who has that, but I designed that, and we used Schott-Jena glass which was delivered just before the cutoff of deliveries. Leon Barnes did the work. Then also Harvard through my efforts and general interest started building its Jewett-Schmidt telescope.
DeVorkin:That was initially going to be a 6l-inch?
Baker:No. The 61-inch is a standard reflector.
DeVorkin:I have a report from Shapley, one of the reports of the directors, where they were planning a 61-inch Schmidt.
Baker:You mean, in this time period?
Baker:Because the subject came up for the Southern telescope. Well, then that was discussion that Iím not aware of at Agassiz. The Southern telescope was an F/5 telescope, and it could have been modified into an F/2.5 Schmidt, which is a little bit too fast for it. On the other hand, Shapley had ordered a new mirror, which had arrived just the same time I did in í35, but from the Fecker Company. One of the sad things was that in Ď36, I guess it was í37; the mirror was damaged during a silvering cycle. We called in Professor Gerrish, the senior engineer here at the Observatory, and had the misfortune that the older Common mirror was thin, and it was plate glass and of course from the old days. Itís still out at Agassiz I think, in a box.
DeVorkin:The A.A. Common Mirror is?
Baker:Yes. Still there. Though it must have been moved since I was last out.
DeVorkin:Hasnít it been sent to the Smithsonian or anything?
Baker:If so McCoskey must have done it without my knowledge. I havenít been out enough lately to know. I am going to be out there next week.
DeVorkin:It would be interesting to know.
Baker:Anyway for many years it was half-aluminized, half clear, and it was sitting there in the box with a plate glass front, standing on edge for everyone to see. But I havenít been out at Agassiz for a long time. When the new mirror came and was installed, it was thicker. The first operation on it was to silver it, because in those days aluminizing was still in its earliest stages. Thatís a separate story. You should have an interview with John Strong because heís much older than I am and his life was full of experiences.
Baker:I saw him about three weeks ago and we had cocktails together and we were babbling along at a great rate about all these old stories. Strong had succeeded in aluminizing the 100- inch telescope. He was startled when Dr. Adams offered him observing time on it rather than anything else. He needed money I guess more than he needed observing time.
DeVorkin:Oh I see. I didnít know what his position was.
Baker:Heíd give you the straight story about it. Anyway, at Harvard, we were still silvering, so when this new mirror arrived from Fecker, Gerrish had it silvered, and then when he was putting it back into the telescope, he forgot about the cleats that were on the thinner mirror before, which were on the upper surface. So when they used the jack screws to push the new mirror up in place — it went very hard. I guess this must have been in í36. They cracked an edge off of the new 61-inch mirror. I must have already been known to be interested in optics by that time, because Shapley sent me a note asking if I would go out and give him a report on it.
DeVorkin:You mean, it was stuck there in that position?
Baker:No, theyíd backed it off already. But the mirror was out where you could see and the piece that had been broken off was about six or eight-inches long, and a 1-1/2-inches in. But it was all jagged, and there was danger of more cracks going deeper. So I brought out some fine grinding stones and I stoned that down for 20 or 30 hours, rounding that off until everything was as smooth as I could get it. Thatís the way it is to this day.
DeVorkin:And thatís the mirror thatís in use now?
Baker:Yes. So that was just an unfortunate thing. But Iím not exactly sure of the time that might have occurred. Probably during the late thirties, but it may have been later than I think it was. Shapley certainly had confidence in me at the time, from earlier work. Well, in the Junior Fellows, we were talking then about the war. It was also on everyoneís mind in the Monday night meetings. Some of the people coming through were statesmen who discussed Hitlerís schemes and so on. Fission was very well known to us. I think thatís the important thing. Ivan Getting might recall it in more detail, became he was in physics.
DeVorkin:You were noting a minute ago that you were trying to decide how you were going to participate.
Baker:All right. I decided then that I would try to do something, but it wasnít so simple. This is on the tape; incidentally, if you get it from Jim Gagan or if you like I could ask him and get it for you, I know how to reach him. Shapley was also concerned about what one should do and what staff might do. He apparently discussed this with Dr. C.E.K. Mees of Eastman Kodak. Dr. Mees had been closely associated in many different ways with the work in aerial photography going on at Wright-Patterson. In those days it was just Wright Field. Patterson was a separate Air Force base. Wright Field was in Dayton, Ohio, and General George W. Goddard, who had probably as much influence on my life as Dr. Moore had earlier, was in contact with Mees. George W. Goddard is still alive. Heís about 89, I think, down at Boca Raton in Florida. Heís worth talking to. Another life in another area which is again a very complete story. Heís written up some of it himself. Goddard apparently asked Mees if he knew of anybody who could give him a hand with advanced optics. Mees contacted Shapley and vice versa. You may find some correspondence on it.
DeVorkin:Yes. This is important.
Baker:Then Shapley contacted me and the upshot was that I corresponded with Goddard and received an invitation to spend the month of January 1941, at Wright Field as a government employee. So I took leave from the Harvard Junior Fellowship for that month. I went down and spent five weeks, the way it turned out, at Wright Field. At that point Iíd already become sufficiently able to design optics to design the special refracting apochromatic. Iíd also gone through all the optical glasses and had calculated the least-squares formulas for interpolation and even extrapolation of the indices. And so I was fully equipped to know how to design refractic systems. I had already been sufficiently aware of the Schmidt and had written a paper or two on the advanced Schmidt.
DeVorkin:You had written by this time at least three papers on the Schmidt. 
Baker:Right. So I was well aware of the details. The outcome of that was that the Army Air Corps wrote a contract with Harvard University for a group of instruments that Iíd proposed for aerial photography.
DeVorkin:Was this an OSRD contract?
Baker:No, this preceded that. This was in the early months of 1941. At the same time, the preceding fall, Marshall Stone at the Harvard Math department had asked me and Iíd accepted to teach a semester course in theory of optics in the math department at Harvard. So when I came back from Wright Field, I started teaching and gave a full course then for the following four months in the theory of optics.
DeVorkin:Was this for the war?
Baker:No, this was just primarily mathematical.
DeVorkin:And this was before you had your degree?
Baker:Yes, before I had my degree. So then I wrote those lecture notes up and mimeographed them. It seems strange nowadays. They became rather useful to various people who were doing optics later on. Even to Canadians. I wrote up some of Karl Schwarzschildís work and some of the aftermath and consequences of it; general notes on optics. I knew all about the so-called eikonal. Itís a mathematical function which was originally developed by Hamilton, the Irish mathematician and called the characteristic function, but Brunz had adapted it from the theory of mechanics to optics and called it the eikonal. The partial derivatives of it are related to the aberrations of the optical instrument. Anyhow, I taught that. So, from the time the contracts were set up with the Army Air Corps, with Harvard University, and through the Observatory, we set up a laboratory here at the Observatory in the basement of Building D which is our next building over. That started on August 3, 1941. I remember very clearly, on a Monday morning, beautiful morning. I prevailed upon two members of the Amateur Telescope Makers to leave their places of work. One was at a bank. Another I guess was a clerk in some office. I asked them to join me full time here and become my opticians. We were going to do the machine work in a wooden building where the Jewett Schmidt was being built. It was about finished, actually. So, the basement optical shop was set up, and I was busy all through the spring and summer calculating a seven element aerial lens, which was my first really complicated lens design.
DeVorkin:Is this the 40-inch F/5?
Baker:Thatís right. So I did that in six months, and Dave Grey, who is now a professional optical designer and theoretical optician or optical physicist in Waltham, [He operates David Grey and Associates] was a student in my class in the math department, and so he was the only one who really was qualified and really good. He could solve problems the others couldnít tackle. He Joined me. So, the two of us worked on the 40-inch F/5, working our heads off on a desk calculator because we had no automatic equipment. It took well into the summer to finish the design of it, and I wonít wonder when I look back, to see how much work that was.
DeVorkin:Summer of Ď41.
Baker:At the same time I was working with the drawings, designing the mounting and dealing with Wright Field on the details. So the whole thing started up very actively and to say the least, I had to give up any other activities around the observatory.
DeVorkin:You still got your Ph.D. in Ď42?
Baker:Right. But the thing is that the Junior Fellows in those days were not allowed to work for a degree. They could get married but they couldnít work for a degree. Now, if they already had a degree, that was ok, but many a Ph.D. was made a Junior Fellow after the fact. But we were not allow to until it was realized later on, after nearly ten years of the society, that there were certain practical aspects that had to be met, particularly among the medical people. They could hardly practice medicine without having a MD degree. This spread to everyone else. So then by the time of Ď42, Shapley had prevailed on Lowell and others that since I was doing serious war work and already entering professional life I very badly needed the degree. They felt that Iíd already done enough with various papers and various activities to justify it, and so the arrangements were made. Then towards April 1942, Shapley called and said he was very sorry but he would have to have a thesis. And he had to have it by the following Monday morning. This is all around Thursday. [laughter] So I quickly abandoned everything else, got my notes together and typewriter and started working. I gathered my different notes on my nebular papers and other things, so it was a bit of a mixed thesis; astrophysics and optics. But Iíd done all the astrophysical work with Don Menzel. That was still a valuable set of papers. I understand that theyíre still in use.
DeVorkin:They were reprinted in 1952 or so. They were still considered up to date then.
Baker:The only difference is that someone in England, I guess, others have put them onto the modern computers. So they not only improved the calculations but they found an incredible algebra error in the first paper. The first paper is Menzel and Peckeris. It was a paper on the theory of transitions in the hydrogen atom. It was full of algebra, resulting from complex variables and analysis of all the different energy levels, which are full of uís and u primers, going up to the u to the 7th and 13th that sort of thing. Thereís one algebraic misprint. And that crept into all our work. It was only a small error but it caused about a 2 percent error.
DeVorkin:Well, it was all there.
Baker:It was there.
DeVorkin:So certainly by the time, whatever date is given for your thesis, you were working 100 percent on war-related projects.
Baker:I had three people in Ď42 working downstairs, and I had the cooperation of the staff, mostly machine shop and the people in purchasing. So we were able to deliver the cameras in June of í42. We had a wide angle camera employing the Schmidt principle for a lens system that covered 120 degrees. The wide angle Schmidt lens was a concentric optical system which was one of the Schmidt principles.
DeVorkin:Let me ask, how were these different projects delegated? Did you talk to somebody about the need for the aerial camera lens? Did you talk to Goddard about this primarily?
Baker:Well, when I was at Wright Field for those five weeks, I was there on a 40 hour week basis. I discussed the problems of optics and aerial photography with all their own people. Many of them were highly qualified camera people. I saw the equipment they were using and knew the equipment they had ordered and that was being developed: telephoto lenses. And so, the question was what could I do to be of use? And I brought to their attention the possibilities of a wide angle Schmidt lens. Their wide angle mapping systems were the so-called Tri-metrogon. They were three mapping cameras on a common frame.
DeVorkin:Did these people know about Schmidt optics?
DeVorkin:So it was the astronomers who knew about it.
Baker:Oh yes, the astronomers. And then of course there were people at Kodak and at Bausch and Lomb, because they were optics people.
DeVorkin:Iím trying to identify the unique values of astronomers for optics in World War II.
Baker:Well, this was a little earlier. In the following year, Ted Dunham was prevailing on Goddard to have Mt. Wilson build the Schmidt camera for them, and they did. That was in the OSRD Book.  So that was a fairly major undertaking. But itís a very massive camera for aerial photography, considering the focal length. Goddardís interest was primarily in telephotos, because they were compact, and he wanted to put them in fighter planes as well as bombers. He also wanted long focal length because he was convinced that youíd see more if you had a longer focal length. A picture on larger scale is correct, except for modern practice where other things come in. But the wide angle camera appealed to him. Heíd been interested in what was called a strip camera for photographing a continuous strip underneath the plane with film moving over a slit. You correlated the film strip with the image motion of the ground. So this was another way of taking a single snapshot picture of an entire city, say. I designed and built this camera which covered 120 degrees and being a Schmidt it had a curved field. That was the part of the problem which was not very popular among the military people. The photographic emulsion had to be coated on shells.
Baker:On shells of glass molded already to the proper focal length. And we built those shells here too.
DeVorkin:Didnít Whipple have something to do with that?
Baker:That was later. Whipple benefited from the outgrowth of this, because during the course of coating the shells for us Kodak discovered they could mold film. And after the war, when Whipple started the meteor project, I knew from Kodak that theyíd been successful. Then I told Fred to contact the Kodak people because they could mold the film for the Super-Schmidt. So this is how it happened. I didnít know that Kodak had succeeded, except through a cocktail party. Maybe I mentioned that? They spilled the beans when we were all having a good time around there, Ď44, I guess. I wasnít so far gone that I didnít remember it.
DeVorkin:Kodak coated the shells?
Baker:They coated the shells. There were two series. Then early in the war is the camera Iím talking about. There was a four-inch F/2.8 near infrared wide angle lens, 120 degrees. We also designed and built a wide angle projection lens, and designed and built the cabinet and illuminating system for it. It would take the curved glass negatives; project them through to flat undistorted 40-inch square prints. I had two of those built. They were made to furniture quality, of mahogany and everything else, for the projection lenses which were built right here at the Observatory. I drove with those in the trailer with Don Leavitt who took me down to Wright Field. Leavitt was on our staff. This was in June of 1942 already, which I think is pretty good timing, when you consider we started in August of Ď41.
Baker:So this was a major undertaking. And then I started flying. We took the camera up in the plane over Cincinnati and over Dayton, and took some early photographs. The Army Air Force isnít very good at keeping things. I doubt if youíd ever find those any more. But we had the whole thing checked out. We took 40-inch square pictures.
Baker:Right. It was dramatic because the buildings from low altitude were all leaning over on their sides from the point of perspective. But from 20,000 feet, of course, you took in an enormous bit of territory. But it was rugged to do it. There were no windows in the plane, no pressurization. It was cold at 20,000 feet. It was hot at 2000 feet.
DeVorkin:Did you need oxygen?
Baker:We had oxygen. In later flights we went to 30,000 feet. I was checked out on a pressure chamber but probably damaged my health. I went on something like 20 missions at Wright Field during those experimental days.
DeVorkin:Have you retained any of these things yourself?
Baker:No. I wasnít allowed to.
DeVorkin:Do you have any of the optical systems or anything?
Baker:No. Well, yes, in a way. They are all from war surplus. When the war ended, Harvard and all contractors were ordered to give up anything that belonged to the government; the notebooks, the Jab books, correspondence, everything.
DeVorkin:Where did you send it?
Baker:It was all sent to Littauer.  That is, the archivists who were in charge of this gathered it all together, and those things were set up in several filing cabinets in Littauer. And thatís what was boiled down in later years. Iím not sure when. It is just a small stack of things now; correspondence and the reports.
DeVorkin:Right. Your contact was with Clark Elliott?
Baker:Only in the latest time period, right. I canít remember the early people.
DeVorkin:What about the artifacts, the actual lenses and cameras?
Baker:This was a major undertaking. Let me list them, because time is short. There was the 40-inch F/5 which you mentioned, which covered a 9 x 9 inch format. It was only 31 inches long, which is why it was so well liked. It was fast. The exposure times were like 1/800 of a second, so it trapped the motion and got sharp pictures. There was the 40-inch F/5 for the infra-red which we also designed and built. Two of those were under the same initial contract. There were two wide-angle systems. We built only one camera but two projection units. But there was only one cabinet though for projection units so we really had only one working system. This is not well known; we had a 60-inch U shaped telephoto lens that was built.
Baker:It was folded with two mirrors into a letter U. The photographic magazine was a standard magazine built and produced by Fairchild. But we did all the rest, and this was done in coordination with the Fairchild people. Harvard did the contract directly with the Army Air Corps, but Fairchild worked with the mounting; all of that for $7500, if you can believe it and all of that for a year and a half, nearly two years. $7500 for the whole thing — for me, for the optical shop, for the Harvard contract, the glass. From August of Ď41 through about December of í42.
DeVorkin:But you have 47 names that eventually were associated with the Harvard project?
Baker:Oh, that was OSRD. That was after it went over to the OSRD support.
DeVorkin:Weíll get to that in a minute or so. But in these initial projects, there were just three of you? You and Don Leavitt and HargbolÖ
Baker:-ÖAnd Hargbol. He was the chief optician, a lifelong friend. Heís done many fine things. He worked here, Leavitt did too, and we did all this lens work. But because there were only three of us, we leaned heavily on the amateur telescope makers. We already mentioned that. They would come in during the evenings, whenever they could.
DeVorkin:Oh, I see, part-time.
Baker:Oh yes. Right away.
Baker:And we had cabinets with their names on them, Avila and Blake and Cooke and so on. They did various things on weekends, all day Saturday, all day Sunday. Frank Noyes was one. He built polishing machines for us. A lot of work got done in a short time, I think. We all had a purpose, you know. So all this happened on the $7500, and out of that Shapley bought the sheet metal building thatís out in the Yard for $2000. I had my separate Harvard income, which was $2250, I guess. The junior fellowship was more or less destroyed by my having to do this work full-time. For a while Harvard supported me with overhead money at the same rate. The junior fellowship went into abeyance. In the last year finally it was cut off. Thatís why it was five years, not six. Of course we didnít have much money to work with, Goddard wanted to have us design and build some 7-inch F/5 lenses. Iím talking focal length; astronomers would use that for aperture. Dave Grey and I did design work on that. Dave Grey at that time had gone over to Polaroid and started a career there. He did a lot of work in the war for Polaroid on plastic optics. We did work over here for Polaroid too, for molding. I donít see how we did all that, but even during the same time period, for free, we were working evenings on occasion making Pyrex molding tools for some early plastic experiments. We designed and built a 7-inch F/25 plastic lens that Polaroid did the molding for. And I took that to Wright Patterson.
DeVorkin:Were you constantly aware of your role of working to win the war? Was there a patriotic feeling among the amateurs?
Baker:Oh, very definitely. Sure. But now, Pearl Harbor happened December 7 of Ď41, and I remember it very clearly here, because my wife had taken our only boy at the time, Herbie, to Louisville. She was there at the time of Pearl Harbor. I telephoned her when it happened to see whether she should stay there, because we didnít know whether the Germans were going to bomb Boston or not. We had blackouts already. And I remember seeing Shapley that same evening and talking to him about how serious the world scene was. So it was the next day, I guess, that we declared war on Germany and Japan together. So that had a lot to do with it. But it wasnít Jack of information beforehand, because already in August Ď41, four months ahead of time, the general feeling was that war was around the corner.
DeVorkin:Right. The OSRD had already been formed by that time?
Baker:But not so we knew about it or it helped us. My first awareness was when Ted Dunham visited Harvard and found out from Shapley that we were busily at work doing this optical work.
DeVorkin:When was that?
Baker:That was in Ď42.
DeVorkin:Can you remember the month?
Baker:I donít believe I could.
DeVorkin:Early in í42?
Baker:Well, I remember that I frequently met people. I did a lot of optical work, you see, as well as design work, and I would very quickly have to take off my optical clothes and put on my business clothes and go meet someone like Dunham.
DeVorkin:So you hadnít really known Dunham before?
Baker:Iíd known of him, of course, because he was at Mt. Wilson in spectroscopy. In a way I was trying to do the same thing he was. He was building grating spectrographs for Mt. Wilson. I was trying to do it here at the Observatory.
DeVorkin:So that was your first contact?
Baker:It was first contact, but the month I couldnít say. Itís whenever he started his work for OSRD. He used MIT for his OSRD office. I donít know when he first visited Wright Field, but it might have been in Ď42. If he had gone to Wright Field that early, he would already have found our work. But now, to complete the story of what we had managed to do. In September of 1942, I took down the 40-inch F/5. It was mounted in aluminum, because of the light weight required. And I took part in a flight over Cincinnati.
DeVorkin:This still wasnít with the OSRD yet?
Baker:No, it wasnít. It was all Harvard. Still the same $7500 worth. You might find that in Shapleyís correspondence. I hope you do.  In any case, we finished it. That meant we designed and built and delivered a prototype aerial lens ready to use, and put it into the standard camera between August 3 of Ď41 and September of Ď42, which is pretty good by any standard.
Baker:So I flew over Cincinnati taking the pictures myself in full, flying togs from 10,000 to 20,000 feet. I took a focus run to make sure we got the best results, and those pictures were extremely impressive, because we put them side by side with pictures they had been getting with standard cameras. I should say, the cameras available up to that point had really been designs with smaller focal length that had been quickly scaled up and built for the Army Air Corps by Kodak and Bausch and Lomb, without redesigning them for the high precision they really wanted. Those lenses were F/6 a and F/5. Those were improved later and became, in the Kodak case, the Aero-Ektars. And they started using rare-earth glasses and so on but early in the war, based only upon lenses in the thirties, they were really not first rate lenses.
DeVorkin:The lenses that you had worked on in the optical systems, you said some of them ended up on war surplus?
DeVorkin:What models were they?
Baker:The list is 200 items long.
Baker:All the different optical projects. If I were to list them all it would be long. But the ones that are of interest perhaps have to be identified by the year. The 40-inch F/5 was delivered in í42; the 60-inch in í43. And that was flown later in the war over Berlin. That took pictures at 30,000 feet and showed railroad ties. But that was never mass produced, whereas the 40-inch F/5 was. The Perkin-Elmer Corporation made 300 of them, and they were in production by í45 before the war ended. Some of them were sent to the Pacific Theatre. Later on, many of those were used for tracking systems, and then they were used again in the Korean War. Another 300 lot was made then. But then by í44, we had so many people and so many different things going on things became complex. Those reports will tell you what those were, including a fire in the laboratory that affected my throat then, and still has, I guess. We had a phosgene attack, you might say.
Baker:Yes. Iím not sure thatís written up anywhere. We were doing cold chamber testing on the 40-inch F/5, a later model. The camera itself was down around 100 below zero, pretty cold anyway. We didnít have equipment for modern type of refrigerant, so I used dry ice and alcohol. Dry ice wonít wet water but it wets alcohol. So with dry ice and alcohol you can get down to 105 below zero F. I had a cold chamber built of sheet metal and had the camera inside and the alcohol in a cylinder on the outside. Apparently one of the young men was doing some lens edging which involves the use of a torch occasionally. He was playing around with a block of dry ice at the same moment that one of his friends was putting too much dry ice in the alcohol and causing it to boil over, so a moment later the whole place was on fire. I was about 100 feet away in the office when somebody came running saying thereís a tremendous fire in the building, get out as quick as you can. So I phoned the fire department. Then I walked back towards the lab, because the doors were shut, and underneath the door was this bright line of light from the fire. I didnít open the door, but I went outside, and the fire people came. But I was so concerned about the camera that I thought was in the midst of this holocaust that I went around with the firemen, pleading with them not to use their axes or break up anything. All the lights were gore. It was pitch black. Several of us went in together in an attempt to keep the firemen from breaking up the lenses and cameras, at least to watch what they were doing. We had flashlights.
DeVorkin:This was your OSRD shop?
Baker:This was later. This was in í44 when we were in Soldiers Field. Iím jumping ahead. By í44, because of all the agitation with many people in daily work in the shop — amateurs on Tuesday, Thursday, Saturday all day and so on, I took to designing at home as well, as at work. I had people designing for me, using desk calculators. I did some of that at work myself, but mostly I was busy directing everybody. But at home I had a desk calculator of my own, so I would design what I might have otherwise been doing at the Observatory at Harvard. So I designed a 36-inch F/8 telephoto lens, which is interchangeable with the Kodak 24-inch standard lens. It uses the same mount. Those were mass produced later in lots of 500 by four different companies. Kodak certainly, Bell and Howell, Perkin-Elmer and Curtiss Labs, four places. Each built about 500 of them. They were used all during the fifties and early sixties in the B-47ís and the B-52ís and I think even originally in the 36ís but not very many. So that was probably the most mass produced lens, and those are available, still are, from surplus. I have probably half a dozen of them.
DeVorkin:Do you know where the prototype went? Did you actually build a prototype?
Baker:We built two prototypes. In fact there were two versions of the design. We built the first version on a single prototype. We built two prototypes of the second design, which was the one that was mass produced, and those were delivered to Wright Field.
DeVorkin:So they may be at Wright Field?
Baker:Oh, itís very unlikely. They destroy everything periodically. They deliberately destroyed the projection equipment for the wide-angle system in l943, because the two cameras were taking up too much space. I was told afterward, that they wanted to write them off and get them out of the way since they werenít in production.
DeVorkin:Thatís too bad.
Baker:So they destroyed them. But thatís true, not only of my work, thatís true of anybody that ever did contract work.
Baker:They donít have enough room, you see. Too many things are going on, too many new things are being shipped in and too many old things get in the way, so they simply have to do it. So I donít know. Itís possible they were sent around and put in warehouses, but not that Iíve ever known. Anyway, there were other bigger lenses, because this was the end of the old era and the beginning of the new.
DeVorkin:What is the definition of the new era?
Baker:Well, I think of the old era as being when the lenses got bigger and bigger, up to a mammoth lens that I did which had a 32-inch aperture, and weighed I donít know how many tons. This was done by Boston University after the war. I designed it in 1947, a five-element lens, the worldís biggest camera, actually. It has literally disappeared. I have no idea where it is. For many years it was classified and conceivably still is. If itís at Wright Field I donít know where it would be. Iíve asked people down there, without success. But for about six months it was not classified, and it appeared and was described in a Finnish photographic magazine. And then because the Air Force had some use for it, it was classified, and thatís when it disappeared.
DeVorkin:An enormous lens.
Baker:But it was a beautiful lens. It covered a picture size about half the size of the desk.
DeVorkin:About 30 x 30 inches?
Baker:Well, it was a 40-inch diameter field or 30 x 30, yes. It was still getting good photographic resolution at the edges and in the corners.
Baker:Iíd expected the image to be a big blob, you know, but when you put it together, it was a quality image.
DeVorkin:Letís go back and see how the OSRD shop actually was set up [The new era is discussed on page ???]
Baker:Ok. Dunham apparently came and looked over what we were doing and he surely must have seen by this time, in the fall of Ď42 that we had succeeded in building proper aerial cameras of quality. We also had been in competition, in a friendly way, with the Bureau of Standards, because they designed and built a four element system, a Petzval type, for aerial photography and delivered it to Wright Field about the same time I delivered my 40-inch F/5. They were in the lab together. But my 40-inch was about 31 inches long, and their 40-inch, I think it was a 48-inch, was about 72 inches long. So mine was less than half as long. And so from the point of view of general utility production (Carter) were of course interested in the small lens. So, Dunham could have had access to that. Iím not sure that he did have access. But he must have talked with Shapley. In any case, funding beyond Ď42 was always a big issue. We debated having another contract from the Air Corps; it wasnít a very popular thing to do at the university. Although it was war time and anything contributing to the war effort was acceptable. But Dunham decided that we would qualify for OSRD support, and so then we had all the funding we wanted, more than we needed, probably. So we went over to the deposit library and built an optical shop and machine shop over there.
DeVorkin:Deposit library, is that on Soldiers Field?
Baker:Right. Itís on Soldiers Field in Brighton, virtually on Western Avenue, I guess youíd say. Itís very close to where the ďVictory GardenĒ has been on TV for so long. Crockettís Victory Garden is there.
DeVorkin:Oh yes, Iíve heard of that.
Baker:Right across the parking lot. Well, the deposit library had no windows, so we had to put windows in and I think something like $40,000 was spent in re-adapting the building to our needs including ventilation because the books didnít require it and we did. We needed proper heating and all that; office space and partitioning. This took place in early 1943. I donít remember exactly the time that we first started working over there, but I would guess it was in March of Ď43. And after that we hardly ever came to the observatory, except to consult with Dr. Shapley or with the machine shop. Most of our work daily was in Brighton. So the staff grew.
DeVorkin:I see 47 people on the list here.
Baker:Some of those of course including Shapley were just associated.
DeVorkin:Yes. I see Harlow Shapleyís name is on here too.
Baker:Yes, everybody who was associated from the Observatory days.
DeVorkin:Ok, I see.
Baker:For purposes of that talk with the amateurs.
DeVorkin:Yes, all right.
Baker:And any others who occurred to me I will put down. But in the write-up, the last report, there is a complete list, and better dates. The project was very intensive. The amateurs were now professional, because thereís no reason to call them amateurs when they could make precision lens up to 10-inches in diameter and meet all specifications of surface quality and centering and thickness and all at the same time. We also spent many an hour in discussing techniques. Especially with Charlie Evelyn who was a Harvard engineer. So they did many things. They built another wide angle system. Later on that was finished at Boston University. It was a bigger one and that now is in a museum at Rochester, the Eastman Museum.
DeVorkin:During all this, you were working frantically on all these projects.
Baker:Yes, the Old Era still, if you want to call it that — full time.
DeVorkin:You knew the war was coming to an end in í45. Were you thinking about things to do back in astronomy because you did publish one or two astronomical papers after the war on line emission and nebulosity?
Baker:Well, war work is so intensive that perhaps we devoted ourselves; certainly I did, to more than the call of duty. So the average working week was about 70 hours, I would think, and this went on right up to the very end of the war and beyond to the fall of Ď45. When the Japanese surrendered, we had probably a dozen projects still going on. I spent time on the telephone I guess, three and four hour discussions with Ted Dunham on details of projects, including harmonizing B- 29 guns and building a periscope for Navy night fliers to find submarines. Theyíre all listed among probably 50 to 100 projects. When the war ended, we had a new shop. We had amalgamated with people from Underwater Sound Labs. I had a new machine shop and new people in support of our effort. But Harvard decided not to carry this on. The Army Air Corps offered Harvard the building for a dollar, and contracts to carry on the work, but it was not academic any longer. Harvardís policy at that time under Conant had been not to accept any further government support, even to show that Harvard had benefited from the war, because there was a sort of feeling of moralistic feeling of ethics not to benefit from the war. So a building that weíd had put up in the spring of Ď45 was torn down already by the following spring. And it was a building that had been offered for nothing, to Harvard. Under present circumstances theyíd have been delighted to accept it, but this is a different time period.
DeVorkin:So, not at that time. How do you feel about that?
Baker:Well, I felt as if both my arms had been cut off. I mean, I had the budget, I had the people, I had the machine work, the optics, and I had everything going. What I should have done, if Iíd been mature sufficiently, would have been to take a monthís trip around the country, the world, or something, and come back into astronomy. But I made too big a personal issue of it. So I took kind of a Leave, because I agreed with Ted Dunham to spend about four months — it stretched to six, I think — to write up the war work in the Summary Technical Volumes, and that was done at Columbia University.  During that time period, Dr. Shapley, through the staff, asked me to become an associate professor. And that was a high honor, of course. But the salary was $4800 and I had three children already. The trouble was that I was being offered 10 and 12 thousand by Bausch and Lomb and Kodak and such things at the same time. So there was a period of instability. Shapley most kindly gave me this offer, and I accepted. But as I said I had the pressures from outside; from friends in optics and other places where I still wanted to do some work. So we made an arrangement that I could consult one-fourth of my time. So Harvard arranged for the salary to be $3600 for in effect, three-fourths of the time. This was as associate professor. I was to earn what I felt I could earn in other ways. But already I was dealing with Perkin-Elmer Corporation through Mr. Perkin, who was a very able, very competent business executive and who was very interested in optics and astronomy. He immediately put me on a retainer to cover the other fourth of my time. And that of course was very satisfactory from the point of view of income, but it was very hard from the point of view of overlapping time and requirements.
DeVorkin:Yes, because very rapidly you also became a research associate at Lick.
Baker:That was later in í48, yes.
DeVorkin:Still in Ď47, you wrote a paper for the CENTENNIAL SYMPOSIA, on ďLine Emission in Nebulae.Ē 
DeVorkin:So you still had your interest in nebulae, but now it was truly observational, based upon thin film technology. You were showing the importance of interference filters.
DeVorkin:And you were arguing that they should be developed.
DeVorkin:You also mentioned the developments of the war. Did you have anything directly to do with thin film technology for the interference filters during the war?
Baker:Not during. I canít readily say that we did. I was very interested in Cartwrightís work at MIT. And also through Katherine Blodgettís work, I guess at GE that was on soap films for the same purpose, but it was not durable.
DeVorkin:The interference filters you mentioned came from Zeiss, ironically enough.
Baker:Well, although a lot of people were beginning to coat these. Baird associates in those days, which is Baird Atomic now, started coating interference filters, and it was nothing from the point of view of invention. It goes back to Fabry-Perot back in the twenties. But they didnít actually coat anything. They just used plain parallel optical plates of high quality.
DeVorkin:Right. These filters were much better. You learned about them during the war?
Baker:Well, I knew through Walter Baird of their possibilities. We didnít have coating equipment here ourselves, but we used the National Research Corporationís coating facilities, for magnesium fluoride and for aluminum films. But I knew also of Cartwrightís work at MIT on thin films, and I knew also of some British work which was done by chemical coating rather than evaporative. This was done with carbon tet. We used to play around with what are considered toxic materials now. We had trichloro ethylene and carbon tet and toluene. All of us were saturated with toluene which is a carcinogen plus the fire and the phosgene. Of course, there were my high altitude experiences. It was all dangerous.
DeVorkin:Right. Well, what Iím getting at are the types of wartime spinoffs that there might have been for research.
Baker:The first thing that happened when Fred Whipple got back and in fact all the people came back to the Observatory to start in again, Don Menzel wanted to improve the Corona graphic techniques. Fred Whipple wanted meteor cameras to carry on with his work on seeing what the atmosphere is like and what meteors can do. And then the Observatory in general had the ADH project for South Africa, which was to use my design for the flat-field Schmidt in a serious way for astronomy. That was to take the piece of the Bruce Telescope, so that was a postwar project. All these things happened simultaneously. But in connection with my teaching duties, that fall, I taught celestial mechanics, which was an outgrowth of my work in orbits that I liked way back. I taught a full semester of celestial mechanics, and I taught some photography too, since that was easy. And I taught some astrophysics. When Don was out of town, I would give classes from our nebular papers and so on. And I was observing. This paper that you talked about was from observations made in the fall and winter of Ď46, Ď47, because the Columbia work stopped around May. But during the summer of Ď46, with these projects going, I designed the Super-Schmidt — the meteor camera, which later on were built and used as you know by Whipple.
DeVorkin:These were directly for Whippleís projects?
Baker:Right, but certainly they were an outgrowth of the war, because even before we closed down our Brighton Avenue laboratory, Fred had called and asked if I knew any way to improve meteor cameras, because the meteor lenses heíd gotten hold of to date were all too slow. At first I started out on refractive systems, thinking I could go down to F/2 or something like that with a 50-degree field. But that was just as much computation, you might say, as a 40-inch F/5 would have been. But after I started on that, I realized that it wasnít nearly so productive as a cat dioptric system. So then I proposed the Super-Schmidt meteor cameras, which in turn were an outgrowth of the radar projection camera that I did in 1943 in connection with Perkin-Elmer and Roland Corporation of Chicago. In the fall of Ď43, I found a way to build a composite projection unit at about F/.63, which would take a phosphorus screen with electron illumination. It was very bright, brighter than the sun. You couldnít look at it. And this was all inside a vacuum — the optics and everything were made inside of an envelope. And this was made into a projection for radar mapping. After the war, it was turned into a similar scheme for regular TV movie projection. The Super-Schmidt camera design then was related to that. In terms of high image quality it was beyond what television requires. And Perkin-Elmer built 6 of those for Fred Whipple. So that was a very major project. Then on the Corona graph, Jack Evans left his work at University of Rochester and went to Boulder to join Walt Robertís group which was where Menzelís corona graphic work had been taking place up to that point. Walt was at Climax and later on came down to live university at Boulder. The instrument was primarily at Climax. And so Jack and Menzel together wanted to set up a more southern station at Sunspot, New Mexico. As it turned out they called it Sunspot. Itís in the Sacramento Mountains which are really ideal. You get up to 10,000 feet, leave the desert floor and climb up among all the tall Ponderosa pines.
DeVorkin:Yes, itís beautiful up there.
Baker:So I worked with Don, off and on, I guess for three years on the chronographic optics. We were trying to use the war work to advantage. Jack had some things that he wanted too for his filter work. All through the war and earlier, I guess, he had worked on monochrometers, the very complicated things with many parts.
DeVorkin:Where did he work?
Baker:University of Rochester. Toward the end of the war he sent me a full set of optics. I took them over to Polaroid. We cemented or boned Polaroid films in the right places for him. So that was already going on. Right after the war, these made it possible, along with the Fabry-Perot filters and plates, to get down to a fraction of an Angstrom in the solar spectrum at H-alpha particularly to give high resolutions on spectroheliograms. While there was some interest in the Corona most interest was in the spectroheliograms since Corona lines were usually red and green rather faint, and not terribly well resolved. Perhaps the sky wasnít up to it, perhaps the optics werenít up to it, but in any case, the general effort was on the solar atmosphere rather than Corona. So, that all went on during that time period. I was heavily involved in this when I started consulting. I was also involved with military work again through Wright Field then through the Army Air Force.
DeVorkin:You were consulting in optical physics and serial photography at the USAF.
DeVorkin:Ď49 to Ď57.
Baker:That was in an official way, yes. I was doing contract work with them. I was consulting for Boston University.
DeVorkin:Let me ask a few quick questions about the forties, and then weíll leave the forties. First of all, do you feel that astronomers made a difference in their participation in the war, as far as R and D in optics are concerned?
Baker:Well, yes, because I think not only of the Yerkes group, myself, but of various other astronomers, some of whom ended up in optics pure and simple. We had at Perkin-Elmer Lloyd McCarthy and Dick ??? were both in astronomy to start with.
DeVorkin:And they ended up in optics?
Baker:Yes, ended up in optics at Perkin-Elmer, the mainstays of the company in those early days; Especially Lloyd. He was trained at Yerkes under Frank Ross. And Frank had been at Kodak during World War I. In fact, he spent a good part of his life as a physicist at Kodak. And he had done in World War I essentially what I did in World War II designing special lenses for serial photography in the early days, primitive days. So Ross was at Yerkes, and Lloyd took up optics there and went to Perkin-Elmer, which was Perkin-Elmer-Moffatt in its earliest times. Moffatt was an astronomer and then an optical man. He and Mr. Perkin didnít hit it off too well, so they went their separate ways.
DeVorkin:The other question is quite a bit different. Of course you wrote a book with Dmitroff, Telescopes And Accessories. It came out in 1945.
DeVorkin:On approximately page 180, you have a discussion on photoelectric photometry, where you discuss a cesium-cesium-oxide photomultiplier, an actual photomultiplier at Harvard?
Baker:Well, that would be Dmitroff.
DeVorkin:So you didnít have direct with it?
Baker:My chapters were for the spectroscopic ones and all the telescope ones, and photography.
DeVorkin:Did you know anything about photomultiplier tubes during the war?
Baker:I donít think Iím qualified to answer that because it wasnít a concern of ours.
Baker:Yes, I knew about Elveyís work, and Stebbins and the early ones on the photocells. But the photomultipliers I think became interesting to John Hall; John Hall particularly. John right after the war was starting up on that in a big way, and he went to Amherst, and I worked with him on trying to get him some light collectors. He wanted resolving power but he wanted light more.
DeVorkin:A light bucket.
Baker:A light bucket, so this was partly for his photo multiplier. Johnís retired now, you should know. Heís living in Sedona.
DeVorkin:Right. We talked to him.
Baker:The Old School Tie group.
DeVorkin:In 1947, how did you come to develop that 30-inch lens?
Baker:Really it was í33.
DeVorkin:How did you come to make that?
Baker:It was at BU. Goddard was interested in longer and longer focal lengths. This culminated in this very large lens, which we called the Boston Camera. It was made at BU. The money for buying the optical glass was used to help set up the Schott optical glass plant again. It was very, very valuable to the reconstitution of the Schott Company, and except for the fact that the old timers are dead now they would certainly give you a nice story. There is a book on that incidentally, if you donít have it.
DeVorkin:No, I donít. What is it?
Baker:This was the odyssey of the glass people, the Schott people after World War II ended, from Jena to outside the Russian zone, down to a little place near Munich, then to Meinz where they are now. The whole saga of how they took their technical people and as much other technical data as they could with them. So, the Russians got only what was left. But the Russians got all the heavy equipment, and more of the data, more of the people. They took those to Moscow and started the equivalent, and then later on sent them back to Jena so thereís an East German Jena Schott branch or plant. But the West German Schott plant at Meinz of course is the major place. Iíve visited there on several occasions. I was there I guess in Ď54. By that time they had an ultra-modern plant, fully mechanized and automated. It was all electronic.
DeVorkin:Did you ever know what the purpose of this monstrous lens was for? Could it have been for satellite reconnaissance?
Baker:Oh no, it was primarily intended for the B-36, later the B-52. So far as I know it was flown in the B-36.
DeVorkin:There was only one ever made?
Baker:Only one. It photographed a golf ball on a green at 40,000 feet, to give you an idea. There was a saying once, maybe it shouldnít be in print: Can you tell the cows from the bulls? ďYes, look at the shadows.Ē Very clear.
DeVorkin:Thatís marvelous. You don Ďt know where this lens is?
Baker:No, I donít. Iíd like to find out, because when it made no dollar sense difference, or scheduling differences in any way at all, if I already was very close to what astronomers would need, even if it were for aerial photography work then I would go ahead and incorporate the final bit of calculation. So that lens was free of distortion, down to the last micron, in principle. For aerial photography, for what it was doing, ten microns would have been quite ample. But it made no difference, except quality, just to go as far as I did.
DeVorkin:You donít feel it was destroyed, do you? It must be in existence somewhere.
Baker:Well, so many things have been thrown out that I just wouldnít want to speculate.
DeVorkin:Yes. Itís unbelievable.
Baker:Well, for instance, I had some Perkin-Elmer projects shortly after that. One was a 96-inch focal length F/8. I donít know where that is. The other was a 144-inch focal length F/8. I do know where that is. It was never flown because as I say, the old time Era was caning to an end, of the big focal lengths, and so it was taken to St. Louis to the Air Chart and Information Center. It was used in the Laboratory just for a collimator for a long time, without its regard to its being on extreme high quality wide angle system. It has shown up just in recent months, after all these years. I got a letter from a Reverend Hepmar. I thought at first it was a coded name. He is at St. Maryís in Centralia, Ill. Weíre corresponding on it right now. He acquired it. He hasnít told me how. He wants to mount it for use as an astronomical camera. And so he has it, after all these years.
Baker:F/8. Itís a 16-inch square and 19-inch front element.
Baker:He was trying to sell it. He advertised in Sky & Telescope and I didnít particularly want it but I didnít want it thrown out either, so I offered $800, far below its value. But somebody else offered him more. And then when I wrote him in great detail about it, after Iíd identified that it really was the lens I wrote him all about it and so we corresponded back and forth. The person he was about to sell it to backed out of it, so now the Reverend is planning to keep it and use it for instruction in the observatory.
Baker:But at least heís fully aware of the fact that it must be taken care of, as an astronomical instrument. So that too is free of distortion.
DeVorkin:Marvelous. What is the ďnew eraĒ you mentioned?
Baker:Well, in the early fifties, when the Air Force was long since set up and it was backing all sorts of technical studies, there was general interest among scientists in the Western world, including Italy, France, England and Sweden, as to what optics was really capable of doing. So both at open meetings like that and international meetings and at closed research contractual meetings here in this country, the emphasis got to be on getting more and more from the optical image, without having the equipment get super-monstrous. I made a study of it myself and discovered that I could literally look through a total haze. I could photograph things the eye couldnít see, and I demonstrated that in a laboratory.
DeVorkin:Where was this laboratory?
Baker:I had it in my basement out at my house in Winchester. Thatís another whole story, because in 1950 and for 30 years I lived in this 19 room solid brick house. We moved into it primarily to get space and also for optics as well as for the family. And so we had 10,000 square feet of space there. The whole basement was an optical laboratory.
DeVorkin:Were you the only one who worked in it?
Baker:Well, I was the only one who worked in it except for visitors. There were many projects were visitors did come. Not so much that you could see cars out the door every day, but once in a while when something was being discussed. Many projects were finished there. I did some of the alignment and assembly and even some of the optical figuring myself over the years, and I did some astronomical lenses for the Observatory here in my basement, fine figuring them so they would give a wide field of coverage. I also redesigned and realigned them. Those are in use as patrol cameras in South Africa and Agassiz and so on. That basement lab was in existence nearly 30 years then.
DeVorkin:So you had this realization that you could cut through fog, based on work that you were doing in your laboratory?
Baker:Yes. I demonstrated to my own satisfaction that, where I could see nothing, I could photograph as well as ten lines to the millimeter. So when we found out why this should be, the whole trend went toward miniaturization and finer grain film, light-weight equipment and so on, which is what I think of as the modern era. Itís already 2 years old.
DeVorkin:What is the ďwhyĒ? Why were you able to do this? You said, when you found out why?
Baker:Well, when I found out from the lab testing, I donít think it was just myself alone, because I think the same kind of work was going on at Kodak. We discovered that we could go to faster optics, lower F numbers and to finer grain super-refined film, which Kodak of course is excellent at, and to electronic stabilization and general controls and other things to take out image motion where one could expose a little bit longer before the vibrations upset the image. We could put all these in one package, and we found we didnít really need those huge focal lengths. And so, I wouldnít be able to tell you how much improvement one actually can get, but itís substantial.
DeVorkin:Those things are still somewhat classified?
DeVorkin:Well, that brings us to your consultant work, for the Air Force, also to the period when you were a member of the Science Advisory Board in Ď52 to Ď57.
DeVorkin:How do you want to treat these because they are very important?
Baker:Well, I was 100 percent in optics by this time, as you can see.
Baker:I spent two years in California, because Iíd resigned from being professor here in order to go to Lick Observatory.
DeVorkin:You actually worked at Lick full time, two years?
Baker:No. I worked at California. We lived at Orinda, California. I was a research associate at Lick, but by this time, Iíd been receiving so many consulting offers that income wasnít the problem. I didnít need income from Lick but I wanted to be close to an Observatory and I wanted to use the Western skies for doing some work hopefully in those states. I wanted to measure in particular the Einstein shift around Jupiter, just for the fun of it.
DeVorkin:Try to measure gravitational deflection of starlight?
Baker:Right. Einstein mentions that in his paper.
DeVorkin:I didnít realize that.
Baker:Itís about 17/1000 of a second of arc, and itís kind of a challenge. It hasnít been done, to my knowledge.
DeVorkin:I shouldnít think so.
Baker:But the Lick people were doing double star work, down to 2/1000, which is eight times better, after taking hundreds of pictures to do it, but thatís no problem. But I was disappointed when I got there to find the scattered light from the objective was so bad that Jupiter fogged the film before I could get faint enough stars.
DeVorkin:Thatís the 36-inch with all the pits?
Baker:With all the haze on the front surface.
DeVorkin:What caused that, just as an aside, because I donít remember seeing that?
Baker:Well, if you look in Kingís The History Of The Telescope, you will see that that disc was made a number of times by the French before they got one that wouldnít break. It was the crown element, and I suspect, I donít really know, that they kept changing the mixture towards getting something that would be stable and sufficiently homogeneous, something they could stir and anneal. And they had to give up the atmospheric resistance. And so I think itís simply a matter that find grinding and other surface fracturing thatís taken place by aging and by grinding in general has been re-opened up. It was glossed over by polishing. So it was fully polished in its earliest years, but as it ages, the subsurface structure, which is not very strong became apparent. And now, as you look at it with a flashlight, you see countless trillions of circular streaks — phonograph record type streaks.
DeVorkin:Right — (crosstalk)
Baker:Theyíve often talked of re-doing it but theyíve never gotten anybody to take the risk at a reasonable price.
Baker:And nobody could really duplicate the Clark finesse because of the glass. The Clark people got rid of some of their problems by using thin elements, because they knew a lot of the trouble was in the glass in the old days. So since they couldnít get hold of the homogeneous glass, the best way to minimize it was to use less glass. So the elements are all very thing. And then, because theyíre very flexible, they got very good at doing fine figuring on the two sides too. So it probably doesnít have any given prescribed shape. It would have to be duplicated by starting with new glass.
DeVorkin:Yes, star testing it.
Baker:But it could be put in a museum, itís done its work, and be replaced by a modern objective lens. The Schott people could readily make better glass now.
DeVorkin:You were talking about the Air Force.
Baker:Yes. The Air Force work went on for all those years, as I mentioned, very intensively, to the point where my friends thought I was thinking of it as a permanent career. Actually I wasnít. I sincerely was trying to help the Air Force.
DeVorkin:What was your primary work there?
Baker:Reconnaissance. I was trying to do anything and everything to improve the quality of information obtained from aircraft. And while a great deal of it was classified, some of it wasnít, and these large lenses that I mentioned that I did for Perkin-Elmer were not classified. They just tended to be just the latest word, so to speak, at the time. They werenít the only ones. I had a separate contract with. Wright Patterson to design a 48-inch F/4.5 I think it was, yes. That was a competition which I won, and several units were made. Then there was also a 36-inch F/ 3.7 originally, ultimately produced as F/4. Perkin-Elmer made about 300 of those again, I believe. That magic number always seems to be about that. But those never were flown either because they were intended for night photography or the cost of completing the camera equipment and everything else was prohibitive for the budget then and were never carried out except for the lens. Those became surplus and there was a club formed to get hold of these from an Alabama warehouse by interested amateurs. So I bought one for just the cost of the shipping, about $60; a 36-inch F/4. It weighed 300, 400 pounds and took two strong men to carry it. So I bought one through the club, and came home one afternoon and there it was sitting in my driveway, without any cracking.
Baker:Without a box or anything, just sitting there. And the fellow who delivered it knew enough about it not to drop it or to treat it like a barrel. But it wasnít boxed? I donít know what the others were like but I think they were all just shipped out in ordinary freight. For $60, they didnít think they were worth much, you know. But even for the optical glass, they had a few thousand dollars of optical glass in them. In any case, the one I had I decided I wouldnít be using it. I gave it to the Observatory and it disappeared and nobody here seems to know where it went either. It just vanished. For a long while it was in the new building. I once in a while would see magazines on top of it. It had a cover over it. And it vanished. I donít know where it went. But since there were so many of them around, it was no great problem. Whipple had to get some for a satellite tracking project, and he got 17 of them, I believe, out of surplus.
DeVorkin:These were cat dioptric?
BakerNo, straight lenses. They were coated with an orange filter, and people who knew how would take them apart and polish off the filter and open them up to a broader spectral band. But most people stuck with the orange filter the way it came, and had to do then just deep red work. One of them was put up in Greece near Athens to follow the Edgerton flashing light geodetic satellite. So they were used for tracking, but never for full field coverage. The lenses covered 9ĒX 18Ē, but these were all used on 5Ē to 7Ē, that sort of thing for tracking with photographic plates. I donít know where they all are now. They are good lenses. But as far as the 48-inch is concerned, thereís only one of those. But then, the other classified project of course I canít tell you.
DeVorkin:But your basic activities remained in this area, work on projects that were delegated?
Baker:After I spent two years in California I decided that it wasnít as important to me as coming back and circulating more. So we did come back in 1950. And then for five years I was on a half-time basis with Perkin-Elmer. In fact I never stopped being with Perkin-Elmer from 1945 on. But it varied in intensity. In í55 when I came back I was on half time with them, and we did many things, among these was a study on applying automatic computing machinery to optics. We were funded sufficiently well. I had five or six people working for Perkin-Elmer but under my direction, all here at the Observatory. And at the same time, from the tine I came back in 1950, to now, Iíve always been a staff member without salary but with the facilities and privileges, they call it. So I always paid my way then though consulting. But Ií always stayed near Observatories, and of course Harvard is nearest to my liking. So Iíve been here ever since.
DeVorkin:What was your activity for the Science Advisory Board?
Baker:Well, that was a group of men selected mostly from industry, some from universities, in all branches of aero physics. And in my case it started out of course with being primarily in serial photography but it broadened its scope so that we were interested in the applications of aerial photography and field use and I made a tour to Europe to see that different Air Force bases were adequately equipped, and came back from that and we made some improvements. But the rest of it is classified. We had discussions, you know, of what to do. The Korean War was pretty well over by the time I started this, but some of the lessons were coming back to us, as to what we needed. Also my 40-inch F/5 had been used over there, too. So even though it was intended for World War II, actually it was mostly used in the Korean War.
DeVorkin:in the Science Advisory Board, you met physically with other people?
DeVorkin:Were there other opticians, other astronomers?
Baker:Well, Fred Whipple was a member and there were other astronomers occasionally; mostly not. Mostly they were air frame and engine people. Thatís separate. I had a long file on that but most of it Iíve had to burn you know because itís classified. I have only all the meeting dates and places and all that. I still have open correspondence on that. But itís mostly Air Force problems. We talked about satellite systems early.
Baker:Thatís Ď52 to Ď57. In fact, I wasnít unfamiliar with orbital lore because even when I taught celestial mechanics in Ď46, I was giving the class problems on the lowest energy orbits to Mars and things like that. It was all Buck Rogers, but that sort of thing began to be a little more serious in the late forties and certainly very serious in the middle fifties.
DeVorkin:Did you consult at all on satellite reconnaissance, during this early time?
Baker:We discussed the problems. But where it actually began, I have to clam up, so to speak.
DeVorkin:Ok. Iím more interested in your own thoughts about the use of satellites for astronomy, if you had any.
Baker:Iíve always, of course, been interested in these possibilities. I still am and still work on it. My actual practical experience was with the satellite cameras, which are ground stationed, but right after World War II, I was very interested in a major undertaking called a Survey of the sky and in the early fifties, I designed a 240-inch aperture wide angle Schmidt system.
DeVorkin:Aperture or focal length?
Baker:Right. I called it the Super-Sky Survey Telescope. In í46, I was interested in what I called the Solar System Sweeper, and I tried to prevail on Dr. Shapley to finance something that would give us about a 60-inch aperture wide-angle Schmidt type system which would allow me to find all moving elements in the solar system at time brighter than something like the 20th magnitude, but it wasnít timely. It wasnít the time period for it. Astronomy itself wasnít in very good shape. Budgets and new telescopes were needed and so on.
DeVorkin:This was just after the war.
Baker:Right after the war. The problem was getting back in order. I really wanted that as my own postwar pitch so to speak, at least I thought I did at the time. But it wasnít the proper time. Anyway, I called, it the Solar System Sweeper and gave talks on it around here with the idea that doing what the patrol cameras were doing to the 15th magnitude, I thought I could do to the 20th. Then that expanded, because in the early fifties, after I got much more aware of big optics and big possibilities and skills, I designed this Super Sky Survey Telescope, a 240-inch aperture.
DeVorkin:Is that a single monolithic mirror?
Baker:Well, I studied it in all its aspects, including compound elements, and I thought of it as an insectís eye type corrector. It was to be built in hexagonal segments, and now of course weíre still discussing things like this, with the Multi-Mirror telescope. Itís related at least.
DeVorkin:Were you involved in that whole project?
Baker:Just on the side.
DeVorkin:Were you interested in it?
Baker:Interested but not essentially. No, it was a good thing to do. It wasnít new in the sense of bringing multiple parts of an aperture together, because a fellow named Houn díAturo did that in the thirties.
Baker:Itís been done in various optical instruments, splitting up images and recombining them. Itís been done in stereo-range finders, submarine periscopes. All sorts of ways.
Baker:Yes, interferometerís particularly. But the idea of having separate telescopes working together, perhaps itís a little hard to track the roots of that. The Smithsonian people arenít at all sure. There a patent suit going on apparently.
DeVorkin:Between who and who?
Baker:Well, a fellow named Thomas holds the patent on having anywhere from two to six telescopes working together.
Baker:Thomas. Iíd never heard of his name. I donít place him anyway. Heís got a patent in his own name.
DeVorkin:Whatís his first name?
Baker:I have it he. Take a look at it. These are memos. I suppose this is confidential for the time being, all the principals, itís not for publication. ďTelescope having multiple objective mirrors, Warren R. Thomas.Ē Patent number 3,507,547. But itís too early for the public eye
DeVorkin:I thought maybe there might have been some problems between Smithsonian and Arizona about the property of the project. I mean, I know theyíre cooperation and everything.
Baker:Well, I think Aden Meinel was the one who suggested it. I may be wrong but I think so.
DeVorkin:He originally suggested it?
Baker:He knew that there were blanks available and wondered what could be done with it. He devised this compound telescope. Then he brought it to Harvardís attention, as a joint project. I of course sat in on all the early discussions. But I was less interested in the compound aspects than in having one big telescope.
DeVorkin:This is your 240-inch?
Baker:Well, in the fifties, I used to try to prevail on Dick Perkin to get the Air Force interested and so on, but it was years before its time. I went to Germany and talked to the Meinz people and the Schott glass people in the summer of í59 to see what types of glass they could recommend that they could make in such pieces. And they advised me that it was possible to go up to corrector plates to 240-inches at least in a single piece for the correcting plate, but there was to be a super-Schmidt type shell which was an insect eye, and that was to be about 4-inches thick.
DeVorkin:Youíd have a very thin corrector plate, 240-inches in diameter?
Baker:Well, it wouldnít be so thin. It would be about an inch and a quarter, inch and a half.
DeVorkin:And it would hold its own weight?
Baker:It would be supported in the center. You know, like di-fraction arms.
DeVorkin:Right. I see.
Baker:But itís a bigger story than that, because I had several different ways of doing it. I was interested in wedding the Super-Schmidt and the tracking camera designs together. So my first attempt was a compound corrector plate and an insect-eye shell, and a single piece mirror. It was to be stationary. The field was 45 degrees and I visualized having one of these every 30 degrees of latitude, North and South, covering the meridianal patrol, so that the overlap would take care of the whole sphere, and each one then would be a fixed vertical like the original telescopes of G. W. Ritchey. Ritchey had a fixed vertical, you know, but he was using coelostats. So my aim was to use a wide field camera design which would give a 240-inch coverage over 45 degrees of meridian, around the zenith. And so I talked on this at many local meetings, showed slides of it. It was so powerful that one could not avoid seeing Pluto for instance on a proper exposure, because it would be around 15th magnitude, virtually burned out. Its trail would be many millimeters long in an hourís exposure, you see. Actually I was thinking probably of 30 minute exposures as the optimum. But what I had in mind was to cover the whole celestial sphere in several different colors and magnitudes, and to get a completely recorded history of the sky during the few years it would be used and then to convert it to an astrophysical instrument afterwards in every one of the six observatories. I even studied maps to see where they might be located. Almost all unfortunately were in earthquake zones. But that all died away. I designed a 60-inch F/1 counterpart to it, for an intermediate type tracking system, which might still be useful.
DeVorkin:Has that been made?
Baker:Well, no. The 20-inch F/Iís for the Smithsonian satellite tracking programs, of course, were not only made, but the project has gone on for 25 years and itís come to a final end.
Baker:Well, it was after that work that I did the super-sky system and the 60-inch F/1ís. So in the early sixties, I was trying to get people interested. Again it was not the proper time. But now the time is almost ripe again where it might be interesting. The Air Force however has come up with the 48-inch Geodes system, they call it. Geodes are high quality apertures on a 6 degree field, imaged with CCD arrays, I think. The solid state detector arrays. Theyíll be in use by the Air Force for tracking purposes, they are tied in with electronic computers to pick out only the moving objects. Itís a more sophisticated age. I would have had to look among millions of stars you see, to see a moving faint object. One of my purposes was to see if there possibly could be a companion to the sun, but that too has gone by the boards, became the pulsar people can do this without ever going outside of their homes.
DeVorkin:The pulsar people?
Baker:These are all different stories.
DeVorkin:How does the pulsar fit in?
Baker:Well, Iíll very quickly give this. When the pulsars were discovered, and they measured their periods to nine decimal places and so on, they had to correct the period for the motion of the earth.
DeVorkin:Oh of course.
Baker:The motion of the earth depended on the center of mass of the solar system. They thought the astronomers knew all about that. But when they looked into the data, they found out it wasnít sufficiently accurate. So now, if the sun had a companion, all they would have to do was see how to modify their CG to go with the pulsar data and that would tell them where this object is and how big. So the photographic method of looking for a needle in a haystack doesnít work. But anyway, I optimized it during the fifties to my way of thinking. But it comes back again in a different way, because thereís some interest now in making a survey of asteroidal material to see what conceivably might someday be a danger to the earth, especially the so-called Apollo-Earth crossing orbits. And JPL is working on that, and they donít want too much excitement about it.
Baker:Well, they feel this sort of subject is ďBuck Rogers...Ē
DeVorkin:Oh, yes. Yes.
Baker:The movies would get hold of it. The movies already have, because they have this thing called ďMeteorites.Ē
DeVorkin:Was this Icarus?
Baker:It was MIT that got that started.
DeVorkin:I was going to ask about that project. Were you connected with that at all?
Baker:I wasnít then, but I may be shortly.
DeVorkin:How do you think youíre going to be in?
Baker:When they get the need once again to get the fainter objects, to go beyond the Geodes system, which is in being now and actually beginning to be used, they will want something around 120-inches, then I can perhaps do something with some of my earlier work. I had started a 3 meter design F/1. And it could be done, but it would take millions of dollars for good optical work. Thatís still too soon, but later on, when they start looking for fainter meteors, meteorites, which are still serious if theyíre coming in close, and they want to carry the Geodes survey another magnitude or two, then they might need something like what I have in mind.
DeVorkin:Isnít there a fundamental limitation because of our atmosphere? If you talk about enormously large systems, you still have the sky brightness, around 23rd, 24th magnitude at best?
Baker:Well, it itís put in terms of 10th magnitude stars, so itís on the order of a 10th magnitude star for every square degree, something like that. But the limiting magnitude with the 200-inch is touching 24, and outside the atmosphere, theyíre talking of 29, in orbit or from a lunar observatory, which is another long subject. Iíve done some work to see what that might be because the natural thing for me was to take my proposed survey of the sky from the ground into space, where a smaller telescope can do it better. And it turned out that a friend of mine, John Irwin, was thinking on similar lines. Heís published a paper on the uses of the Schmidt for sky survey. I havenít published, so he has the priority to the concept. But in any case, a Schmidt, either on the moon or in orbit around the earth, can in principle go to about the 27th magnitude, not the 29th, because if you get too wide a field of view the faint stars, are eliminated by the brighter stars, and the wider the field you look at, the brighter the primary and the more obscuration of the fainter stars. So there is a limit. I estimate 27 instead of 29. If you had an astrophysical narrow-field telescope, of chronographic quality, then 29 is possible. But the low meteors will be streaking across the field, because even the tiniest dust particle 150 miles away will be bright in the sunlight. And so an observatory on the moon would be really desirable, to keep in the shadow of the moon and have the earthís atmosphere and still have full time communication with the earth. I wish weíd kept one Apollo space ship for that purpose, or several. Thatís something else again. Well, itís a question, because at all times interesting things are going on, and this is true of the Geodes system. In the Air Force for instance theyíre still using the Smithsonian satellite tracking camera, only their own. Every clear night they have four stations going. And theyíre monitoring, along with radar and laser beams, probably 30,000 objects or some very large number. But the camera method can go farther than the radar, because the radarís a 4th power law and the camera is a square law. So when you can get to deep space, so called in modern terminology, why, the cameras once again dominate. So if you want to find a ten foot object, say, thatís coming as close as the moon, weíre going to need our 60-inch F/1.
Baker:If you want to see a ten-foot object a million miles away, weíre going to need the 240-inch.
DeVorkin:YouĎre talking about ground based instruments?
Baker:Well, if the focal length is short. The point you brought up is certainly completely valid, about sky light. That limits exposure. So does the motion of the object. You simply expose as long as the object is making a contrast image for the surrounding fixed stars. And the longer the trail, the easier it is to see.
Baker:But just because the skylight is gone and you double your exposure of time, it wonít help if the objectís moving. So thereís an optimum. The bigger the aperture and shorter the focal length the better, but the shorter the exposure time and so thatís why the low F number and the high aperture.
DeVorkin:Iíd like to ask just a general question or two. Looking back at everything youíve done and all of your projects. You were chairman of the U.S. Committee to the International Commission on optics?
Baker:Yes, for three years. I was president of the Optical Society in Ď60.
DeVorkin:Youíve also garnered quite a few medals and awards. Letís just take all of that together and ask you, what was the most satisfying thing that youíve ever done in your own career?
Baker:I wouldnít quite use that word, because Iíve been interested in all these things in terms of challenges, you might say, itís always satisfying that you finish something thatís a challenge. There have been several rather difficult projects. One of them is classified again, canít mention that but it was very difficult. But one is the wide angle Air Force mapping camera thatís called the Geocon; I coined the name for it. That took place primarily in the middle sixties and is still ongoing. But itís a mapping system where I designed 95 degree coverage, free of distortion, to about 5 microns. And it goes along with a lot of electronic gear and recording techniques that the Air Force developed. But it was very hard to make the first lenses, because the requirements of alignment were so severe. It had something like 12 elements.
Baker:Right. And these all had to be aligned in such a way that a light ray coming through at 47 degrees off axis would end up within 5 microns of where it belonged, see. And I did some of the alignment assembly and aspheric figuring work in my basement lab in Winchester. It was near the limit of what I could do, certainly, but I managed. I also designed what I called a poor manís testing device.
DeVorkin:A testing device?
Baker:Well, in the actual industry, at Gosshomo or Fairchild, when theyíre testing mapping lenses, they had a whole battery of collimator lenses or individual telescopes which are in a framework. These are all carefully aligned with a Veldta spectrometer so that their angular directions are precisely known. And identical photographic targets are placed, for all of these, and photographed all at once, and then reduced. The equipment costs a quarter of a million dollars , you see. Well, in my undertaking to do this in my own home, without having any such need for such equipment or any such financing, I did it in a much simpler way. Temporarily, at least, I took two plates of optical glass that I figured plane parallel, and put them at a wedge angle in an aluminum cell, so that collimated light would go back and forth, each time doubling the wedge angle. I had a zero order, 1st order, 2nd order and so on. Each would have twice the angle of the other. Then I calibrated knife edges so I could tell exactly where these were on a slide that was driven by a fine micrometer screw and also a dial gauge. I could measure where the image lies to something like 2 microns. Then I had a scale calibrated at MIT on their super comparator, so I knew what that was. Thereafter I was able to work in my basement lab and work to a couple of microns. This was all just to build the thing. Then after that I took it down to have it tested at Fairchild and to see if it really did work. That all went slowly. But it did go forward and was finished. So I guess there are about 20 such systems in use at the Air Force for precision high altitude mapping. But as I say, the number of projects all together must have approached 200, or at least 100. I have never listed them all. Many of them are so classified they never will be known, I guess. I have put a lot of emphasis on light weight optics, trying to get more with less weight; astonishing small weights actually.
DeVorkin:Have you done anything with space optics then?
Baker:Well, I have talked with all my friends for year after year after year to space optics. And I am a consultant still and have been since 1967 in the Aerospace Corporation.
DeVorkin:Thatís right, sure.
Baker:Iím going out on Wednesday and be there Thursday, to discuss these very points. But whatever comes up I discuss as a consultant, in all the different problems of optics, whether itís image quality or stability or structure or magnitudes or spectral band widths or whatever even the theory of optics. Iíve sort of been steeped in this all these years, and some of itís astronomical. I have been working rather loosely, to be sure, with Professor Columbo here, whoís working on space applications of various things. Heís very ingenious and has developed the idea of dangling piano wire literally from satellites, what he calls the gravity gradient, both going outward and coming inward. What he plans to do is put an instrument in the upper atmosphere from a satellite which is much higher up, and the instrument down below to measure what it sees in the upper air. The thing is that if the satellite were in the upper air, it would have too much drag and would come in too soon, but by having a big satellite out in a farther orbit, there will be less drag and this wire has the same period, of course, and so it also stays radial, because itís carefully set for drag.
DeVorkin:How long is this wire?
Baker:Ten miles, 20 miles.
DeVorkin:I see what youíre talking about.
Baker:And it doesnít weigh all that much. If the wire is that long, that low, it will break of its own weight. You have to dangle it within its own strength. But you can do it with a certain technique with a wire of a certain diameter, at a certain distance, where half of its strength is used to hold itself and the other half is available. You have a wire twice the thickness which can carry on the next and then twice up and so on, after you go up about six hierarchies until you get a wire that big and you stop, you know. But when you get farther out, the wire can be longer.
DeVorkin:Iíve heard of stories like this.
Baker:If you get out at 10,000 miles, you can have wires many, many miles long. When itís close in, then itís limited. On the other hand, that very fact is also correlated with the atmosphere. That is, the effective height of the atmosphere is a gravity gradient too. So it depends upon whatever he wants to explore at whatever height. Thatís the kind of thing. But he had me working on a scheme of weather control for the earth which is all Buck Rodgers and I hope will actually never happen.
DeVorkin:On weather control?
Baker:Weather control. He wants to control hurricanes by shadowing them, and I figured out a way that one can do this in principle, but it is beyond mankind.
DeVorkin:Yes, I would think so. Large shadows to get rid of the temperature differentials?
Baker:You go to the inner Lagrangian point, which is a million miles toward the sun, and which is the instable equilibrium point. You put an annulus there which is made up of counter rotating prisms probably made of sapphire plates, very thin ones, which rotate this way and direct the sunlight either toward or away from the earth. The whole thing is rotating for stability. At such a point on a large angle you can either warm the earth up, or if you want to, you can put a shadow over the earth and by rotating prisms you can track a shadow right across following a hurricane that way. I calculated the masses required. It would have to be made from lunar dust — about 7 kilometers in diameter. It would take centuries. So itís beyond mankind. But I went through the arithmetic just to have fun.
DeVorkin:I can see why youíd have fun with the MIT students.
Baker:Well, thatís what heís doing. Columbos a professor there and heís been there all semester, working with astronauts. I would like to add that I do think the survey of the universe from the moon, before our large budgets disappear, or even from orbit, would be a most valuable project to plan whoever gets to do it. There is a catch to it. Don Nicholson has pointed out at Aerospace that if youíre in a close-in earth orbit and youíre trying to do wide angle stellar photography with high precision, you run into differential stellar refraction. The high velocity and changing direction in orbit, which is comparable to 5 miles a second (say the earth was 18-1/2 miles a second in solar orbit) the aberration constantís about 20 seconds of arc in the earthís orbit, and so this is one-fourth, nearly one-third that speed which would amount to five or six seconds of arc. And so an exposure time, going from one part of the orbit to another, would cause the star images in the outer field to move differently from the inner one.
DeVorkin:Because the field is large?
Baker:Because the field is large. So if youíre guiding on the one at the center of the field, the ones on the outside are doing differential ellipses. They are differential with respect to what youíre guiding on. And so it turns out that this would bring 15 microns displacement on a field 90-inch aperture F/3 Schmidt. That with a 20-inch square field and presumably a solid state array instead of photography amounts to about 15 microns, which is enough to jump from one detector to another, and so on. But it canít be neglected altogether. I found ways to stretch it that would overcome it and you start over here within the orbit and stretch the film progressively as you go across.
DeVorkin:But if you were actually on the moon?
Baker:On the moon you would have the lunar dust to contend with, which no doubt would be very aggravating. But if you select a point, this has been done by various people, on the lunar equator at some elevation where the earth is not at the zenith from the site but off to one side still allowing full time communication, then as this goes around in the lunar cycle, you could in principle, with one telescope, cover virtually the entire celestial sphere, throughout the years, and communicate directly in real time, to the earth. So such a telescope, working narrow field to the 29th magnitude, working wide field to 27th, would be an invaluable tool for surveying the universe, zooming in on whatever was of real interest. But Iím so afraid and have been all these many years, that once the large budget enthusiasm has been replaced by depression and gloom that all the possibilities may come to an end. They almost already have, in terms of the Apollo program. I donít think the American public would finance such a program. Itís hard enough to get the shuttle going.
DeVorkin:Yes, I hope it will be.
Baker:But theyíll carry that through. But thatís making it very difficult for other space projects. Anyway, I mentioned the survey and as I say, John Irwin had it independently and wrote it up. But regardless of that, I think it extremely important. Another project is to improve astrometric astronomy, and thatís another separate story. Iíve been interested over the years in doing that. One outgrowth of that is to use the techniques for looking for planetary companion and nearby stars. Three or four professional astronomers have been working on that very assiduously. Peter van de Kamp of course has been doing this with the Sproul refractor for most of his mature life.
DeVorkin:Do you have any comments on present criticisms of his work by Gouge and Gatewood?
Baker:Gatewood in particular, and Eichorn do feel (skeptical). Theyíve looked at his data and theyíve looked at their own, which is more limited, but they find no evidence of it, other than instrumental effect. So Iíd guess youíd have to say, the general feeling is that Peter just didnít have the proper equipment.
DeVorkin:Is it possible that he could have such long term temperature or instrumental effects in his equipment? Because it looked like it was a systematic effect.
Baker:Well, he had certainly got what amounted to orbits out of it, first one object, then two, I guess. But Gatewood is a younger fellow who has looked into it more, and Eichorn has been on the theoretical side, so I just really go by what they say. On the other hand, thereís no reason why proper equipment couldnít have been built. It just wasnít. And it doesnít necessarily have to be a refractor. It doesnít necessarily have to be a reflector like the one at Naval Observatory in Arizona.
DeVorkin:The 16-inch, yes.
Baker:Because that was optimized according to Strandís own wishes, following Rossís views on it. But I think there are other ways to do that. Each has his own. In fact, they had a conference of astrometric astronomers, and I donít know how many came, 30? And they had 30 different ways of doing it. But there has been general interest in using electronics and space optics to try to get a better look at planetary companions. There have been studies. For example, Lyman Spitzer has made a study of what might be done with super-telescopes out in solar orbit. He reaches rather pessimistic conclusions. But I did a study on a tessellated refractor like the Houn díArtuno tessellated reflector? Iím not sure, the word for the individual piece is more like tessary. But the adjective Iíve seen used is tessellated. Anyway, itís a compound system. I designed a 2000-inch for use in solar orbit for this purpose.
Baker:The individual plates are made by interferometry on earth. Itís all part of a very long focus lens. These are stacked, bound with pink ribbons and so on, and taken up on the shuttle and finally accelerated into a solar orbit, assembled one place or another. The focal length is something like 20 miles long, and the telescope is far away. But then you have another ordinary telescope like a 100-inch reflector which picks up the lens part, which is 20-miles away or more. And anything it sees through the lens and through the telescope, which is sort of like a big eye piece, has light coming from the remote universe. So when this zeroes in on some star like Sirius or more likely Capella B or something, this would have a resolving power of a very small fraction of a second of arc. And since it is lens-like and corona graphic in general character, it barely becomes possible to see to about the 26th magnitude in a way that would separate out the planetary companion of a half phase angle from the primary. And so this is within the reach, you might say, of a major project.
DeVorkin:People were saying that the space telescope should be capable of seeing Jupiter-sized objects around red dwarfs.
Baker:Yes, because when the primary is fainter and your planetary companion isnít too far away, then youíre in pretty good shape to do it.
DeVorkin:Thatís not the same order of magnitude problem youíre talking about. Youíre talking about earth-type planets around solar-type stars.
Baker:Right, or at least Jupiter type. The whole array, down to whatever is possible.
Baker:The optics is ok. It just means you have to either deal with some glass types that donít exist, or you deal with long focal length thin elements. But each one has to be so thin that the phase delay through the plate is hardly more than you expect of an interferometer plate. And so it all gets together in a remote area. Then the best location is one of the two equilateral triangular points which are stable points in the earthís orbit, either preceding or following the earth. Because then you could set up a telescope of any length at all and it would not be disturbed. You could then zero right in on some star and keep it locked in —especially one thatís perpendicular to the ecliptic.
DeVorkin:Right. That would make it easier.
Baker:Right, that would make it a lot easier. Just keep it the there. So these two things: a survey of the universe, whoever does it, and the astrometric precision needed for planetary companions: those are two favorite projects. I have a lot of others.
I wish you all the luck in the world and outside of the world, with them. Weíd better close off now. Thank you very much.
Amateur Telescope making (Scientific American Publication)
American Association of Variable Star Observers
ApJ 84 (November, 1936), 474
Publ AAS, 9 (1939), 255; Popular Astronomy, 48 (1940)
Summary Technical Report of the NDRC: Vol.1 "Optical Instruments" Washington, D.C., 1946
Archival storage at Harvard
Optical Shop file, Harlow Shapley Director's Correspondence. HUA
Op. cit. NDRC text
Harvard Observatory Publ., 1947