Chapter 5

"EMBELLISHED BY
A DISTINGUISHED MAN"

THE COUNTDOWN for the Copernican Quinquecentennial built toward a climax in December of 1972. Charles Eames wanted to open his exhibition in the IBM building on Madison Avenue in time for the crowd of Christmas shoppers, so I flew to New York on several occasions to help with the labyrinthine assembly of the panels and artifacts. Edward Rosen came up from City College to lend his critical eye to proofreading the captions. He corrected a few minor errors but overall was quite pleased with the comprehensive presentation.

As the installation reached its final stage, the staff assigned me the task of keeping Charles occupied so that he would no longer make schedule-breaking improvements in the show. To create a dramatic Christmas showpiece on the street side of the exhibition, he had enlarged to mural proportions a page from Julius Schiller's idiosyncratic Coelum stellatum Christianum con-cavum of 1627, which had turned the constellation Pegasus into the angel Gabriel. Charles wanted to color the stars, so I read out the spectral type of each star from the Yale Bright Star Catalogue, and he dutifully used his Magic Markers to give each one its proper color, a characteristic level of sophistication for the Eames office, but entirely lost on the passing shoppers.

While in New York City I took the opportunity to see yet another De revolutionibus, one I hadn't previously recorded, at the Pierpont Morgan Library. It was my hundredth first edition, what collectors call an association copy, in this case a presentation volume from Johannes Petreius, the Nuremberg printer.

The books I had seen fell into four categories. There were a handful of three-star copies—on a Michelin Guide system, "worth the trip." These included the Reinhold copy in Edinburgh, the book that launched the census; Michael Maestlin's fabulously well annotated copy in Schaffhausen, Switzerland; and Harrison Horblit's presentation copy from Rheticus, the ultimate association copy since Copernicus did not himself live long enough to autograph a copy. The two-star copies—"worth a detour"—included one in Copenhagen originally owned and annotated by Matthias Stoy, one of Rheticus' students at Wittenberg who later became professor of mathematics at Konigsberg. Like Horblit's three-star copy, where Rheticus had canceled Osiander's anonymous introduction "To the Reader" with a red crayon, Stoy's copy had the same red cross-out, strongly suggesting that the copy had come directly from Copernicus' only disciple. Another two-star copy was in Toronto, probably the one originally belonging to Philips Lansbergen, a seventeenth-century Dutch astronomer and table calculator. It had an interesting piece of misinformation inscribed at the end of the Os-iander introduction to the effect that the Parisian scholar Petrus Ramus thought that Rheticus had written that introduction!

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The angel Gabriel from Julius Schiller's Christian constellations of 1627, a street-side mural in the Eames Copernican exhibition at IBM headquarters in New York December 1972.

The one-star copies—what the Michelin Guide would merely call "interesting"—included the Morgan Library copy and one in Leningrad whose anonymous annotations contained a list of biblical verses that seemed to stand against the mobility of the Earth.

The proper classification or relevance of some of these starred copies was by no means obvious when I first examined them. Often the books became important only in retrospect, when I could make other connections with them. For example, if I had figured out who the first owner was to whom Petreius had presented the Morgan Library copy, and why that first owner had carefully canceled the Osiander introduction, it could well have won another star.

And then there was the fourth category, the large number of also-rans, with only trivial annotations or none at all. Because the books had been sold as stacks of paper that the buyer sent to the binder to be finished according to his tastes and his pocketbook, each copy was different. I carefully measured the height and width of their pages, figuring that someday this physical detail might help track a stolen copy, and I recorded the names of the previous owners whenever possible. Eventually, even these unannotated copies helped to demonstrate the movement of books and showed that the second edition, published in Basel in 1566, had particularly helped supply copies to Italy and England.

THE SPRING OF 1973 found me heading to Cairo, courtesy of American grain surpluses. In the 1960s the granaries of the American Midwest were bulging with corn and wheat, brought about in part by generous farm subsidies. Congress, having got into this particular pickle, found an ingenious way out. With Public Law 480 they arranged to send the grain to needy countries—including Poland, Yugoslavia, Israel, Egypt, and India—with the corn and wheat paid for in soft currencies. In other words, the United States found ways to spend the proceeds within each country rather than demanding hard cash. In turn, Congress allocated these funds to various government agencies including the National Science Foundation and the Smithsonian Institution.

Some of the Smithsonian's PL480 funds proved very useful for my Copernicus census, because they could be used to buy air tickets from agents within those countries. I helped organize a translation program in Poland to get certain key Polish Copernican scholarship into English, and another program in Egypt to catalog the many unexplored astronomical manuscripts from the Islamic period. Both TWA and PanAm had offices in Warsaw and Cairo, and there was no problem using the tickets they provided to stop off at various points to survey copies of De revolutionibus.

By April of 1973, when I was heading on my annual trip to check up on the Islamic astronomy project in Cairo, my Copernican notes were extensive enough to give a pretty good idea of the way in which the book was used in the sixteenth century, sometimes as an object of intense study, and sometimes as little more than decoration on a library shelf, casually perused at best. Having by then examined more than a hundred copies, surely sufficient for statistical purposes, I was tempted to say that enough was enough. Nevertheless, Rome beckoned, because I knew there were more unexamined Copernicus imprints in that metropolis than in any other single place. Copies were to be found in the Biblioteca Nazionale, in the Accademia dei Lincei, at the Vatican, and in the Biblioteca Casanatense. The latter library, named after Cardinal Casanate, who later became head of the Inquisition that had sentenced Giordano Bruno to the stake in 1600, unexpectedly turned out to have Bruno's De revolutionibus, a second edition. Bruno had been sentenced as a heretic for a plethora of heterodox ideas, including the plurality of worlds, but he seemed at best rather ill informed about Copernicus' ideas. His De revolutionibus contained a bold signature but no evidence that he had actually read the book. In any event, his Copernicanism was not a major factor in his conviction. Bruno's copy was a surprise, but when I arrived in Rome, the really big discovery awaited me at the Biblioteca Apostolica Vaticana.

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Giordano Bruno's bold signature in his De revolutionibus, now in the Biblioteca Casanatense in Rome.

Visitors to Rome have no trouble seeing the magnificent Vatican art collection because the Vatican Gallery abuts the edge of Vatican City, and tourists can enter to view the paintings and sculptures without needing to enter the Vatican grounds themselves. The Vatican Library is another matter, located more deeply in the territory of the Holy See. There was then (and probably still is) a visa office with full Italian-style bureaucracy. And here was an occasion when a Harvard "dazzler" letter stood me in good stead. A senior colleague had alerted me that the office of the University Marshal would prepare an official-looking document with an enormous gold seal that could help budge recalcitrant bureaucrats. Armed with my dazzler letter, I apparently passed muster. In those days gentlemen were required to wear a coat and tie. Ladies could work in the library only in the morning. In the afternoon, with no women present, men were allowed to hang their jackets over the backs of the chairs. That was one of the rules. I was asked if I wanted to see books or manuscripts.

"Books. Here are the shelf marks," I said, handing over a list of call numbers that Jerzy Dobrzycki had given me.

"But this is a manuscript," the clerk responded, pointing to one of the shelf marks on the list, Ottoboniana 1902. Puzzled, I asked for permission to see both books and manuscripts.

The Ottoboniana collection is especially interesting for Copernican studies. After the death in 1632 of King Gustavus Adolphus of Sweden, who had waged the Thirty Years' War to save northern Europe for Protestantism, with his officers helping themselves to libraries and art collections along the way, his scepter and the war loot passed to his daughter, Christina. Among other things, the twenty-two-year-old Queen Christina had hired the famous French philosopher Rene Descartes as a private tutor. The fifty-three-year-old Descartes, who was used to lying abed meditating till eleven every morning, was shocked by a regime that required him to get up for philosophy tutorials at 5:00 A.M. Alas, this chilly routine caused his demise, and he died in Stockholm in 1650, less than a year after his arrival. Soon thereafter Christina decided to abdicate, pack up her treasures, journey to Rome, and take up the Catholic faith. When she died in 1689, Pope Alexander VIII (the former Cardinal Ottoboni) acquired her library, whence it became part of the Vatican Library.

Knowing this piece of history, Jerzy Dobrzycki had gone to Rome for a systematic survey of the Ottoboniani, hoping to discover some unknown Copernican materials that had been confiscated by the invading Swedes and subsequently transported by Christina to Rome. Jerzy noticed that Ottoboni's collection included a copy of De revolutionibus, which had been classified as a manuscript volume on account of the extensive annotations bound at the back. Remembering that Copernicus had received the complete book only on his deathbed, Jerzy knew it couldn't have come from Copernicus himself, so he marched on in his survey, except that he copied out the shelf mark for me. Without that, I might never have found this copy, since it wasn't recorded in the catalog of printed books.

Inside the reading room there was another rule: only three books per day. But the library had two first editions and two second editions in the catalog of printed books, plus a rare copy of Rheticus' Narratio prima, and several other books I hoped to look at as well as Ottoboniana 1902. Eventually, after I had got a special dispensation from the prefect to exceed the limit, the fetchers at the circulation desk looked daggers at me. "Young whippersnapper!" they probably thought. "Who does he think he is that he can actually read six books in one day?"

One of the examples of De revolutionibus in the Vatican's printed books collection turned out to be quite special: a presentation copy from Copernicus' printer to the polymath Achilles Permin Gasser (who came from the same hometown as Rheticus). On the title page Gasser had penned part of a Latin poem, not a great classic but interesting:

By his renowned new theses, Copernicus

Is believed to have put the finishing touches to this art

Which Erasmus Reinhold eagerly grasped,

As a Thesean cord, and paved a sure path to the stars,

And, striving to surpass the Alfonsine labors, Shows how great he was in the celestial art*

This De revolutionibus annotated by Gasser had been part of the library of Heidelberg University, generously "given" to Graf von Tilly, the brilliant Bavarian Catholic general in the Thirty Years' War, to become a major part of the foundation of the Vatican's library of printed books.

But the real thriller for me in the library that day was Ottoboniana 1902, and it was my turn to be dazzled. On its title page was a familiar motto: "The axiom of astronomy: celestial motion is uniform and circular or composed of uniform and circular parts." Clearly, the book had some connection with Erasmus Reinhold's copy, the book in Edinburgh that had precipitated the entire census, and which had the same motto penned on its title page. The link was confirmed by several of the extensive notes in the book itself, which matched some of Reinhold's. But there were annotations graphing the technical details of the planetary mechanisms not found in Reinhold's copy, and at the end, a wonderful series of diagrams showing at first the Copernican Sun-centered circles for the planets but then switching to Earth-centered arrangements. The transition point was specifically dated: 13 February 1578. A final geocentric diagram was labeled "the spheres of revolution accommodated to an immovable Earth from the hypotheses of Copernicus." The label seemed an oxymoron, since to us the essence of Copernicus is heliocentrism. How could the diagram have been both Copernican and geocentric?

This was extraordinarily exciting but extremely puzzling. Whose book could it possibly have been? The final diagram smacked of the geoheliocentric scheme proposed by the great Danish astronomer Tycho Brahe, not quite his final system but a logical stepping stone. In 1588 Tycho had proposed a system with the Earth at rest, with the Moon and Sun circling the Earth, but with the Sun carrying all the other planets in a retinue around it. Tycho was undoubtedly the most productive astronomical observer the world had yet seen. Night after night he had measured positions of the stars and planets, using precision instruments of his own design in the decades before the invention of the telescope. Convinced both by the reality of what he was observing and by a commonsense conviction that the Earth itself was immobile, he had sought a cosmological solution that preserved the elegant connections of the Copernican arrangement together with a solidly fixed central Earth. Published in his De mundi aetherei recentioribusphaenomenis*his Tychonic system bore an uncanny resemblance to the diagram at the back of Otto­boniana 1902. The Vatican diagram showed the Earth at rest in the center, with the Moon and Sun circling the Earth, but only Mercury and Venus circling the Sun. The outer planets still rode on epicycles, although a simple geometric link would have had them circling the sun, essentially switching their epicycles with the Sun's own circle. While in Ottoboniana 1902 there seemed to be some sort of embryonic generic relationship to Tycho's system, the Danish observer was already accounted for; I hadn't yet seen his copy, but it was well known to be in the Clementinum Library in Prague. The only clue to the ownership of Ot­toboniana 1902 was that an early librarian had written in Latin on the title page, "embellished with autograph notes from a distinguished man." Who was that distinguished man?

Among the possible candidates that Jerry Ravetz and I had mentioned three years earlier, one stood out: Christopher Clavius, the Jesuit astronomer who had organized the Gregorian calendar reform. He had originally come from Germany, where he just might have seen Reinhold's thoroughly annotated De revolutionibus. In the 1581 edition of his thick textbook, Commentary on the Sphere of Sacrobosco, he had conceded only that Copernicus simply showed that Ptolemy's arrangement of the circles was not the sole possibility. If Clavius had made the 1578 notes in Otto­boniana 1902, the timing would have been just right for him to have added the remarks about alternate arrangements of circles into the revised 1581 edition of his textbook.

Leaving the Biblioteca Vaticana in a state of higher consciousness, I pondered my next move. The following day was already accounted for: A note at the hotel told me that Massimo Cimino, director of the Rome Observatory, would fetch me and show me the observatory's Museo Coper-nicano, which contained both a first- and second-edition Copernicus. I hoped he might also get me into the library of the Accademia dei Lincei, the famous scientific society with historical links back to Galileo's day, and which, like the observatory's collection, held both editions. Cimino arranged it perfectly, and I saw all four books the same day. One was censored according to the instructions issued by the Inquisition in 1620 (with the replacement text in a very unsteady hand); another had the same places marked but was not actually censored. And another copy had minor notes written in London in 1605, a neat demonstration of the slow reshuffling of books over time.

Cimino was helpful in another important way: He put me in touch with Father D. J. K. O'Connell, S.J., the retired director of the Vatican Observatory. I told Father O'Connell what I had found, and asked him if he could help me obtain a sample of Clavius' handwriting. He replied that the Jesuit archive was downstairs from his apartment, and that he was sure he could find something. Our paths converged in the Vatican Library reading room the next morning. Father O'Connell had in hand Xeroxes of two Clavius letters neatly bracketing the date of the annotations. We were quite excited by the prospect of what the comparison might show. Placing the letters alongside Ottoboniana 1902, we looked carefully both at individual characters and at the "ductus," the general flow of the hand. It took only five minutes to be sure that Ottoboniana 1902 had not been annotated by Christopher Clavius.

I left Rome in an agitated state, turning over in my mind possible can-

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Title page of the "Tycho Brahe" copy of Copernicus' book in the Clementinum in Prague.

didates, but I was stuck. The blocked-currency PL480 air tickets allowed a certain amount of creative scheduling, so I backtracked to Paris for one of the many Copernicus conferences scheduled in that quinquecentennial year. I vaguely recall chairing a session—not an easy task because several of the papers were in French and my aural French was pretty primitive. But I clearly remember my surprise at meeting one of the Czech scholars, Zdenek Horsky. Normally, he had a problem getting out from behind the iron curtain, but he had ghostwritten a Copernican lecture for the president of the Czech Academy, and the trip to Paris was his reward. Horsky had brought me a gift: a facsimile of the Prague De revolutionibus with the Tycho Brahe annotations. When I looked at the handwriting, I think my heart must have skipped a beat, for it looked suspiciously reminiscent of the hand I had just been poring over in Rome.

As soon as I got back to my Paris hotel, I checked my notes from Rome. There were too many coincidences to be accidental. Had Tycho annotated a second copy, and had I found a crucial intermediate stage in his thinking? I contacted PanAm, rebooked my flights, left Paris a day early, and headed back to Rome.

Father O'Connell accompanied me to the Vatican Library, both to smooth my way and to share the comparison between the Prague facsimile and Ottoboniana 1902. This time it took only five minutes to be thoroughly convinced that the hands matched, that Tycho had clearly annotated a second copy. The next step was to get photographs of key manuscript pages. Normally, this process could take from six weeks to six months, but Father O'Connell's presence was magic. He arranged for them to be completed in a few hours.

While we waited, Father O'Connell suggested that we go next door to the Vatican Archives to see the papers from Galileo's trial. That was an intriguing prospect, for the archival record contained not only the transcript of the infamous 1633 heresy trial but various ancillary pieces of evidence, including the famous "false injunction" supposedly issued in 1616 requiring Galileo neither to hold nor teach the Copernican system. The Galileo scholar Giorgio de Santillana had argued in his book, The Crime of Galileo, that the document was a forgery designed to frame Galileo. For many years I felt that the injunction was probably a genuine document that had been prepared but never notarized because it had never actually been served while Galileo was being interviewed by Cardinal Robert Bellarmine, the leading Catholic theologian who had been instructed to warn Galileo about the dangers of holding the Copernican view. But the most modern scholarship today indicates that notarization was not required, and the injunction was quite probably actually served. In that scenario Galileo conveniently forgot about it since he had also received a letter from Cardinal Bellarmine explaining what had happened and giving a more liberal reading. That letter, introduced as evidence in the trial, is also in the Vatican file.

Alas, the archives were closed for lunch, so Father O'Connell took me above the archives to the Tower of Winds, which not many visitors see because the stairway is too narrow for traffic to go both ways. "When Queen Christina turned up at the Vatican, the very timid Pope Alexander VII installed her as far away from his own quarters as possible," O'Con­nell explained as we ascended the stairs. "So he put her here, underneath the old observatory. It's a very unusual observatory because it was used just with a small orifice for sunlight and a brass meridian line on the floor. That way Clavius could show Pope Gregory XIII that the Julian calendar was ten days out of synchronization with the seasons.* The walls themselves have frescoes representing the winds, and that's why it's called the Tower of the Winds."

Once we were in the frescoed room itself, Father O'Connell pointed out that the allegory of the south wind was represented by the storm on the Sea of Galilee (from the account in all the synoptic Gospels), with the opening for the beam of sunlight in the mouth of Auster, the south wind himself. O'Connell went on to say that there had long been a tradition of painting over some potentially offensive detail after Christina arrived. When restorations of the frescoes were undertaken, the overpainting came to light: a scriptural motto under the north wind paraphrased from Jeremiah, Ab Aquilone pandetur omne malum (All bad things come from the north).

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The planetary system, "accommodated to the immobility of the Earth from the hypotheses of Copernicus,"from Ottoboniana 1902 in the Vatican Library.

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Tycho Brake's geoheliocentric system fromhis De mundiae ianeetrhe i recentioribus phaenomenis (Vraniborg, 1588)

Presently the photographs were ready; I thanked O'Connell heartily for his intervention, and carried on with the PL480 journey to Egypt. My mind was aswirl with the unexpected serendipity of my visit to the Vatican Library. When I had started my census, my goal had been to find something new about Copernicus with which to celebrate the Quinquecentennial, and here it was in spades.

BACK IN THE United States, I began to examine how the new discovery fit in with what we knew about Tycho Brahe. The Danish astronomer had published in 1588 his well-developed Tychonic system, with its fixed central Earth and with the Sun carrying the retinue of planets around it. Included was his claim that he had invented this cosmology five years earlier, that is, in 1583. But the diagrams in the Vatican De revolutionibus were dated 1578. However, they didn't show the completed system, and they were wrong in a crucial way. The final geocentric diagram in Ottoboniana 1902 placed the epicycles for Mars, Jupiter, and Saturn so they could glide perfectly past each other without bumping. It was as if they were made of crystalline quintessence—the heavenly "fifth element" of Aristotle— solidified and polished over the passing years of the medieval period. Unfortunately for the elegance of this arrangement, the reality of the planetary spacings required that the epicycle of Mars overlap with the sphere of the Sun. There was no question about Mars colliding with the Sun— the actual motions prevented that. But it looked unaesthetic, if not downright dangerous.

To Caspar Peucer, Erasmus Reinhold's successor as the astronomy professor in Wittenberg, Tycho wrote a revealing letter about the genesis of his system: "I was still steeped in the opinion, approved and long-accepted by almost all, that the heavens were composed of certain solid orbs that carried round the planets, and . . . I could not bring myself to allow this ridiculous interpenetration of the orbs; thus it happened that for some time this, my own discovery, was suspect to me." Finally, he realized that crystal spheres are just a figment of the imagination and not required by the Bible. Freed from the limitations of crystalline spheres, he could allow the intersection of Mars's circle with the Sun's, so that's how he depicted the Tychonic system in his 1588 publication. And Ottoboniana 1902 revealed the trail of discovery, moving step by step from a heliocentric back to a quasi-geocentric arrangement. Furthermore, because of the underlying layer of Reinholdian annotations in the book, there was a clear connection between Tycho and the Wittenberg school. "This is a tremendous scoop," I had written to Miriam from the Rome airport. "It changes several things in the accepted Tycho biography [about how and when Tycho conceived of his Tychonic system] and it dramatically confirms my hypothesis that there was an intellectual link to Tycho via Erasmus Reinhold."

I decided to use the discovery as the centerpiece of my Invited Discourse at the opening of the Extraordinary General Assembly of the International Astronomical Union in Warsaw that August of 1973. For that I would borrow a technique from Charles Eames. He had pioneered the use of multi­screen shows, such as the one in the IBM pavilion at the New York World's Fair in 1964. Afterward he had made a series of in-house three-screen slide shows, which I had seen several times at his offices in California, and I had helped him make one on Copernicus for an international symposium cosponsored in Washington by the Smithsonian and the National Academy of Sciences earlier in 1973. So I captured some slides from Eames and added many of my own, including a few new pictures of the Tycho annotations.

The Smithsonian photographer nearly balked when I told him I needed a hundred glass slide mounts for my forthcoming lecture—the actual number turned out to be 135. And my Polish hosts gulped when I told them I needed three screens and three projectionists. In the end, though, after a rehearsal, we managed to synchronize my lecture and the triple projection, which offered evocative views of Copernican Poland, of Copernicus' library, of the manuscript of his book, together with images of annotated copies of De revolutionibus.

I N POLAND I was shown the text of a speech to be given by the chairman of the Ministry of Health's advisory council, and was able to spare him some embarrassment. Copernicus was understandably popular in Poland that year, and it seemed every politician wanted to connect the astronomer with his own specialty. This appeared particularly promising for the Ministry of Health, because, after studying medicine in Padua, Copernicus had practiced as a doctor in his homeland. In reality, details of his medical career are difficult to come by, but the staff of the ministry's advisory council had found an article on Copernicus and the buttering of bread in the Journal of the American Medical Association. The article described how, during the wars against the Teutonic knights, Copernicus realized that the Polish soldiers were getting ill from contaminated bread. By placing a spread on the bread, one could tell immediately when a loaf had fallen into the dirt. So Copernicus allegedly not only carried out some hygienic research but put his findings into practice to avert an epidemic. The story involved a plausible but entirely unknown official named Adolph Buttenadt,* who popularized Copernicus' finding so effectively that the process was called Buttenadting, which was eventually shortened to buttering.

When I showed the article to Jerzy Dobrzycki, he roared with laughter, having spotted the fable immediately. A physician and a historian from the University of Vermont, Arthur Kunin and Samuel Hand, wishing to raise some issues about the roles of research and practice in medicine, had invented the Copernican story and the fictitious Buttenadt as their vehicle. However, the chairman of the Ministry of Health's advisory council didn't understand idiomatic English that well and thus hadn't detected the obvious spoof.

Later I mentioned the article to Professor Edward Rosen, who had made a career out of setting everyone straight on Copernicana. Rosen exploded. "That's not a hoax," he exclaimed, "that's fraud!" It turned out that the story had a deliriously ironic twist. By chance I met Arthur Kunin at a dinner in Vermont. Kunin told me that he had been a young student in a class taught by Rosen at City College of New York and had been so impressed by Rosen's enthusiasm for Copernicus and his attention to historical details that this probably set the stage subconsciously for their selection of Copernicus for their parable!

BEFORE THE quinquecentennial year was over, I had several more occasions to spotlight my Vatican Library discovery. One was a Scientific American article on Copernicus, and another was a lecture in Boulder to the largest audience I had ever addressed, approximately 1,200 persons, more people than I would have imagined to be interested in Copernicus in the entire state of Colorado. And, at the close of 1973,1 repeated my three-screen show before the American Astronomical Society in Tucson.

Notwithstanding my excitement over the discovery of the annotations in Ottoboniana 1902, there remained at least two nagging questions. In Reinhold's copy in Edinburgh, he had carefully numbered and labeled the three alternative arrangements Copernicus proposed for eliminating the equant, but the technical diagrams in the Vatican copy had started in midstream "according to the second hypothesis of Copernicus." What had happened to the first? Also, there was a geographic table of longitudes and latitudes of many European cities written on a flyleaf at the beginning of the Vatican volume. Why was Wratislavia in Silesia near the top of the list, but Copenhagen and Uraniborg—two places of fundamental interest to Tycho—omitted?

The answer to one of these questions was about to come as an unexpected bombshell. The final reprise for the Copernican anniversary took place in the fall of 1974, at the annual meeting of the History of Science Society. The historians of science decided that one of the sessions would highlight the Copernican discoveries that had been made during the quin­quecentennial year, and I was asked to describe the new Tycho manuscript. I drove from Cambridge, Massachusetts, to Norwalk, Connecticut, where the meeting would be hosted by the Burndy Library, an independent institution with an impressive history of science collection.* I had already inspected the Burndy's first- and second-edition De revolutionibus several times, most recently when I had helped dedicate a new bust of Copernicus for the library garden. Thus, instead of heading straight to Norwalk, I asked my passengers if it would be okay with them if we stopped for an hour and a half in New Haven so I could reexamine the first edition in Yale's rare book collection.

The Beinecke Library in New Haven is certainly one of the world's most beautiful. Thin polished slabs of marble let light into exhibition areas that girdle a central core of glass-encased book stacks. The entire architecture exudes an aura of quiet opulence (plate 8b). I already knew that the Beinecke's De revolutionibus was thoroughly annotated and clearly one of the most interesting copies in America. Thus, I had brought along my camera and photoflood lamps—the latter transported in a special suitcase that the Eames office had made for me—and I was installed in a small workroom. Soon the book was brought in, with its vellum binding and fragments of green silk ties that had once been able to hold the book tightly shut. As I restudied and photographed the book, I realized anew that the annotations echoed many of those in Erasmus Reinhold's copy. It had clearly been annotated in the Wittenberg circle, in two successive hands, but thus far the identity of its annotators had eluded me.

As I worked with the Beinecke copy, I slowly became more aware of its distinctive binding. Suddenly, something clicked. At the start of my survey of Copernicus' book, a particularly useful reference was a list of seventy first editions compiled in 1943 by Ernst Zinner, an eminent German historian of astronomy. Besides this compilation of locations of De revolutionibus, Zinner's German book on the reception of Copernicus' teachings included several other appendixes. One of them listed the sixteenth-century library of Johannes Praetorius—a student and then a teacher at Leipzig and later a professor at Erlangen—which contained two first editions of De revolutionibus. Zinner was a redoubtable bibliographer and loved estate lists like that, especially when most of the books had come to rest in the same place, in this case in Schweinfurt in northern Bavaria. But one of Praetorius' two copies of De revolutionibus was, I knew, not present in Schweinfurt. The list from 1625 (or soon thereafter) was quite explicit; it described the copy as "inn hollend. Perment unnd griin seiten Bender, cum animadversionibus Joh. Homelij et annotationibus Praetorij."* I looked carefully at the binding: Besides the Dutch vellum, here were the traces of the green silk ties, and inside there was evidence of two distinct hands. Annotations in several places cited Homelius, Rheticus' successor as astronomy professor at Leipzig, and these annotations were sometimes accompanied by further notes in a different handwriting, later identified as belonging to Johannes Praetorius.* I had just stumbled upon the missing book, an important link in the early dissemination of the Copernican doctrine because the annotations revealed yet another copy influenced by Erasmus Reinhold's notes.

The most amusing part in the New Haven book came at the end of a long Latin critique of a place where Copernicus was examining the length of the seasons. Unfortunately, there was a typographic error at precisely this point. Even though it didn't actually affect any of the subsequent calculations, Homelius (whose original annotations had been copied by an unknown student into the book) expressed his exasperation and finally broke into German:

Der Himmel ist aber zum Narren worden er musz gehen wie Copernicus will. (The heavens have become a fool if they must go as Copernicus wants.)

In a state of euphoria I rounded up my passengers and headed on to the meeting at Norwalk. "I knew something had happened in there," one of them, Father Joseph Clark, later told me. "Your eyes were just dancing!"

I still have the manuscript of my talk in Norwalk, but I can't remember how much I added about my latest finding in the Beinecke Library. Mostly, I discussed my identification of Reinhold's book in Edinburgh, how it led to the Copernican census, and how I had identified Tycho Brahe's working notes in the copy in the Vatican. As was the custom at these meetings, my paper was followed by a commentator, in this case Robert Westman of the University of California in Los Angeles, a younger scholar who had come into prominence in the Copernican year. After my initial discovery of Reinhold's copy in Edinburgh, he too began scouting for other annotations in De revolutionibus. I knew I was in for some competition after Westman had sought out the annotated copy from Michael Maestlin, Kepler's teacher—a copy which I hadn't yet inspected— and had presented a widely admired paper that included a discussion of Maestlin's annotations. So there was some obvious rivalry between us, and though by the fall of 1974 I had located more than two hundred copies of the first edition, I had by no means seen them all. So I didn't know quite what to expect that Sunday morning in Norwalk.

Westman started out innocuously enough, commending my discovery and raising a few polite criticisms of my borrowed use of the twentieth-century sociological term invisible college to describe the network of sixteenth-century copying of annotations from one book to another. Using two projectors to produce side-by-side images, he compared the Vatican handwriting with a known Tychonic document and pointed out that they were not perfectly identical. Perhaps, he suggested, one of Tycho's assistants might have made the annotations. It was a puzzle, he said, and here was another: He quoted me as saying that the comparative pattern of annotations in the Prague and Vatican copies was made "apparently with little rhyme or reason." It seemed he was leading up to something, but what? I hadn't a clue. And then he sprang his surprise.

Westman had obtained a microfilm of a well-annotated De revolutionibus at the University of Liege in Belgium, and lo and behold, he had found yet another copy with handwriting matching the copies in Prague and the Vatican. This was almost unbelievable. Tycho was a wealthy nobleman, so he could have afforded three copies of Copernicus' book. But why would he have wanted three copies?

I was stunned. I knew at once that I couldn't discuss Ottoboniana 1902 definitively without taking into account the newfound Liege copy. I had been aware of a first edition there, but it had not been my procedure to ask for a microfilm before I had actually looked at a book. Westman had stolen the march on me by writing letters to many institutions and requesting microfilms when the descriptions sounded promising. The trauma of his coup has completely blotted out my memory of who else was on the program that Sunday morning.

Half a dozen of us went out to lunch together that noon, across the highway from the Burndy Library at Old McDonald's Farm, a rather funky theme restaurant saturated with rural atmosphere, and a favorite watering hole on trips from Boston to Manhattan. Against a background of old farm implements and circus posters, Westman and I approached the situation as warily as scorpions in a bottle. Gradually, the tensions ebbed as we realized that the only rational resolution would be to join forces in describing the Tycho Brahe material. Although there would be tempestuous days in the future, it was in retrospect one of the happiest decisions I've ever made. If nothing else, I had much more fun working with a colleague than in isolation. Our research strengths were remarkably complementary, and what we eventually produced was far more interesting than either of us could have managed alone.

The Liege copy resolved a principal mystery surrounding Ottoboni­ana 1902. It contained notes in two different hands. The earlier layer was a remarkably exact copy of Reinhold's notes. This, then, was the source for the title page motto and all the other Reinhold material in the Vatican copy. That early layer of annotations also included a page of notes, apparently from Reinhold, but now missing from the Edinburgh copy—an analysis of the planetary circles "according to the first hypothesis of Copernicus." With that analysis already in place, it was no longer puzzling that the Vatican annotations began with the "second hypothesis."

But there was still no clue why the table of geographic coordinates in Ottoboniana 1902 listed Wratislavia so conspicuously and omitted the key Tychonic locations, Copenhagen and Uraniborg. That would come back to haunt us.

* When in 1551 Erasmus Reinhold had issued the Copernican-based Prutenic Tables to surpass the Al­fonsine Tables, he had "paved a sure path to the stars," showing how great Copernicus was as a celestial artist. Reinhold explicitly stated that the Prutenic (or Prussian) Tables were named in honor of both Copernicus and Duke Albrecht of Prussia (a potential patron).

Heidelberg is still exercised by this perceived theft; Tilly himself was eventually defeated and fatally wounded by the Swedes under the command of Gustavus Adolphus, who had already captured Copernicus' library for Sweden.

* "On very recent phenomena in the aethereal realm," that is, about the Great Comet of 1577.

* The meridian line was calibrated, and each noon when the solar image crossed it—far toward the south in summer, when the sun was high in the sky, and toward the north in winter—observers could determine the date. However, according to the Julian calendar, the Sun was reaching the equinox point ten days too early.

* Adolf Friedrichjohann Butenandt (1903—55) won the 1939 Nobel Prize in chemistry for his work on sex hormones; can the similarity of the name in the fable be accidental?

* The Burndy Library was the creation of Bern Dibner (1897-1988), a retired industrialist who had personally selected the books for his outstanding collection. In 1976 he gave the main part of the rare books to the Smithsonian Institution as a bicentennial birthday gift to his adopted nation. These books are now housed in the Dibner Library in the National Museum of American History in Washington, D.C. The remainder of the collection is found in the Burndy Library of the Dibner Institute in Cambridge, Massachusetts.

* "ln Dutch vellum and green silk ties, with the remarks of Johannes Homelius and annotations by Praetorius."

* The identification was made by comparison with Praetorius' astronomical notes preserved at the University of Erlangen in Bavaria.