Category Archives: History of Astronomy

Who created the first scientific map of the moon? – I expect better of the British Library

Who created the first scientific map of the moon?–I expect better of the British Library

On 9 March the British Library Prints & Drawings Twitter account (@BL_prints) tweeted the following, accompanied by the illustration.

This is the first scientific map of the moon and was produced in Paris by astronomer Giovanni Domenico Cassini. Working in the 1670s, Cassini used a telescope to make careful observations of the moon’s surface.


Source: British Library

This is of course historical rubbish Cassini’s being by no means the first ‘scientific’ map of the moon and I thought who ever runs the @BL_prints Twitter account really ought to up their historical game then I followed the link to the British Library website and discovered the following text:

This is the first scientific map of the moon and was produced in Paris by astronomer Giovanni Domenico Cassini. Working in the 1670s, Cassini used a telescope to make careful observations of the moon’s pock-marked surface. Thanks to the map, 17th-century European scientists had a greater understanding of the moon than they did of much of the Earth’s surface.

If you look very carefully at the map, you will find a ‘Moon Maiden’ hiding behind one of the craters. It seems that either Cassini, or the map’s famous engraver Claude Mellan, included the detail, believing that this tiny part of the moon’s surface looked like a beautiful woman.

Somebody at the British Library really needs to improve their knowledge of the history of astronomy in general and of selenography in particular. For anybody who doesn’t already know, selenography is the science of the physical features of the moon. Selenography is to the moon what geography is to the earth.

Interestingly the first scientific map of the moon was made before the invention of the telescope by William Gilbert (1540–1603) some time before1603. It was, however first published in the text De Mondo Nostro Sublunari in Amsterdam in 1651. No attempts to accurately draw the surface of the moon have survived from antiquity or the Middle Ages if they ever existed. Gilbert also regretted that no such drawing from antiquity existed because he would have liked to compare and contrast in order to see if the moon had changed over time. Although made without the assistance of a telescope the moons features are recognisable on Gilbert’s map.


William Gilbert’s Map of the Moon Source

The earliest known telescopic drawings of the moon were made by Thomas Harriot (c. 1560–1621), a sketch in 1609 and a full map in 1613.


Thomas Harriot’s initial telescopic sketch of the moon from 1609 Source: Wikimedia Commons

Harriot’s map is of course much more detailed than Glibert’s and displays a high level of accuracy. Harriot, however, never published his moon drawings and they remained unknown in the seventeenth century.


Thomas Harriot’s 1613 telescopic map of the moon Source: Wikimedia Commons

The first published drawings of the moon were, of course, those notorius ones of Galileo in the Sidereus Nuncius, which I won’t reproduce here. They can’t really be called maps of the moon as they bear little or no relation to the real moon and might best be described as studies of hypothetical lunar features.

Christoph Scheiner (1575–1650) also produced accurate drawings of the moon in the early phase of telescopic astronomy which he published in his Disquisitiones Mathematicae de Controversiis et Novitatibus Astronomicis in 1614.


Christoph Scheiner moon drawing Source

The Dutch astronomer and cartographer Michel Florent van Langren (1598–1675) published an extensive telescopic map of the moon in 1645.


Michel Florent van Langren Map of the Moon 1645 Source: Wikimedia Commons

This was followed by the even more extensive telescopic map of Johannes Hevelius (1611–1687) in his Selenographia, sive Lunae descriptio in 1647.


Source: Wikimedia Commons


Johannes Hevelius Map of the Moon 1647 Source: Wikimedia Commons

Next up we have the lunar map of Francesco Maia Grimaldi (1618–1663) and Giovanni Battista Riccioli (1598–1671), which supplied the nomenclature for the lunar features that we still use today, and was published in Riccioli’s Almagestum Novum in 1651.



Riccioli/Grimaldi Map of the Moon 1651 Source: Wikimedia Commons

This last is particularly embarrassing for the British Library’s claim that Cassini’s is the first scientific map of the moon, as Cassini was a student of Grimaldi and Riccioli in Bologna and would have been well aware of their selenographical work.

Even if we discount Galileo’s lunar diagrams as not particularly scientific, Cassini comes in, at best, in seventh place  in the league table of lunar cartography. I really expect an institution as big and famous as the British Library, with its world-wide impact to put a little more effort into their public presentations of #histSTM.








Filed under History of Astronomy, History of Cartography

The emergence of modern astronomy – a complex mosaic: Part VI

Copernicus first put his concept for a heliocentric cosmos in writing in a manuscript that today bears the title Nicolai Copernici de hypothesibus motuum coelestium a se constitutis commentariolus (roughly translated: Nicolas Copernicus’ short commentary on his hypothesis about the movement of the celestial bodies) of which three manuscripts are known to exist today. None of them, however, in Copernicus’ own handwriting. There is almost no direct evidence for the existence of this document in the sixteenth century and almost everything that we can say about its origin, its distribution and its impact is based on reasonable, speculative interpretation of indirect evidence.

It is disputed whether the title Commentariolus, for short, was written by Copernicus or was added at a later date; it has been speculated that it was added by Tycho Brahe, who possessed a copy, which is one of the three surviving copies and is now housed in the Viennese Court Library. In his Astronomiae Instauratae Progymnasmata (1602) Tycho wrote that his copy was given to him by Thaddaeus Hagecius (1525–1600). He also said that he had made several copies and distributed them to friends.


Title page of the Viennese Commentariolus manuscript Source: Wikimedia Commons

The Viennese manuscript was first found in 1877 but it is incomplete, missing a substantial part of Copernicus’ lunar theory. In 1881 a complete manuscript was found in the library of the Stockholm Observatory bound into a second edition of De Revolutionibus, which had been the property of Hevelius. The third manuscript was also found bound into a second edition of De revolutionibus that had belonged to Duncan Liddel (1561–1613) in the library of Saint Andrews University in Scotland. Liddel studied at various North German universities and was later a professor for mathematics at Helmstedt University before going on to qualify as a physician and becoming a professor for medicine. A fairly normal career path in the sixteenth century. He knew Tycho Brahe and visited him at least twice on the island of Hven. It should be noted that all three surviving copies of the Commentariolus were owned by people who lived after the publication of De revolutionibus and the death of its author.

The first probably mention of the Commentariolus occurred in 1514. The Cracovian physician, geographer and historian, Matthias of Miechow (1457–1523) noted in a library catalogue in the Jagiellonian Library dated 1 May 1514 the following:

Item sexternus theorice asserentis terram moveri, Solem vero quiescere

A quire of six leaves (sexternus) of a theory asserting that the Earth moves whereas the Sun is at rest.

It is assumed that this is a reference to the Commentariolus, probably a copy originally given by Copernicus to his Cracovian friend Canon Bernard Wapowski (1450–1535) a cartographer and historian.


Excerpt from the library catalogue of Matthias von Miechow (1457–1523) 1. Mai 1514 with the Commentariolus hint: „Item sexternus theorice asserentis terram moveri, Solem vero quiescere“. Source: Wikimedia Commons

There are no direct references to the Commentariolus before the publication of De Revolutionibus in 1543. However, there are various episodes in Copernicus’ life that can probably be attributed to knowledge of the Commentariolus.

Paul of Middelburg (1446–1534) sent out a general call to astronomers and rulers asking for suggestions and contributions towards a proposed calendar reform at the Lateran Council (1512–1517). Paul noted in 1516 that one of those who answered that call was Copernicus in a letter that no longer exists. Perhaps Copernicus was on Paul’s list because of the Commentariolus, he had at this point published no other astronomical works that might have motivate Paul to consult him.

In 1533 Johann Albrecht Widmannstetter (1506–1557), who was a papal secretary held a series of lectures to an audience of Pope Clement VII and some cardinals outlining Copernicus’ heliocentric theories for which he was richly rewarded by the Pope with a rare manuscript. It can be assumed that his source of knowledge of those theories was the Commentariolus.  Following the death of Pope Clement in 1534 Widmannstetter became secretary to Cardinal Nikolaus von Schönberg (1472–1537), who wrote a letter to Copernicus in 1536 concerning his theories and offering to have the manuscript of his theories (De revolutionibus) copied at his expense. This letter would be included in the published version of De revolutionibus.

In 1539 Martin Luther (1483–1546), in his cups, reputedly launched an attack on Copernicus’ heliocentric hypothesis, as recorded by Anton Lauterbach in the Tischreden (Table Talk) first published in 1566. (More details here)

There was mention of a certain astrologer who wanted to prove that the earth moves and not the sky, the sun, and the moon. This would be as if somebody were riding on a cart or in a ship and imagined that he was standing still while the earth and the trees were moving. [Luther remarked] “So it goes now. Whoever wants to be clever must agree with nothing that others esteem. He must do something of his own. This is what that fellow does who wishes to turn the whole of astronomy upside down. Even in these things that are thrown into disorder I believe the Holy Scriptures, for Joshua commanded the sun to stand still and not the earth [Jos. 10:12].”

Copernicus was not mentioned by name in Luther’s tirade and also no great details of the hypothesis. It can be assumed that indirect knowledge of the Commentariolus had come to Luther’s ears.

Our last possible indirect knowledge of the Commentariolus can be attributed to Georg Joachim Rheticus (1514–1574), who famously persuaded Copernicus to publish De revolutionibus. Rheticus set off for Frombork in 1539 already aware of the fact that Copernicus was propagating a heliocentric hypothesis. Did this knowledge come directly or indirectly from the Commentariolus?

So what does the Commentariolus consist of? In a very brief introduction Copernicus writes:

           Our Ancestors assumed, I observe, a large number of celestial spheres for this reason especially, to explain the apparent motion of the planets by the principle of regularity. For they thought it altogether absurd that a heavenly body, which is a perfect sphere, should not always move uniformly. They saw that by connecting and combining regular motions in various ways they could make any body appear to move to any position.

Callippus and Eudoxus, who endeavoured to solve the problem by use of concentric spheres, were unable to account for all planetary movements; they had to explain not merely the apparent revolutions of the planets but also the fact that these bodies appear to us sometimes to mount higher in the heavens, sometimes to descend; and this fact is incompatible with the principle of concentricity. Therefore it seemed better to employ eccentrics and epicycles, a system which most scholars finally accepted.

Yet the planetary theories of Ptolemy and most other astronomers, although consistent with the numerical data, seemed likewise to present no small difficulty. For these theories were not adequate unless certain equants were also conceived; it then appeared that a planet moved with uniform velocity neither on its deferent nor about the center of its epicycle. Hence a system of this sort seemed neither sufficiently absolute nor sufficiently pleasing to the mind.

Having become aware of these defects, I often considered whether there could perhaps be found a more reasonable arrangement of circles, from which every apparent inequality would be derived and in which everything would move uniformly about its proper center, as the rule of absolute motion require. After I had addressed myself to this very difficult and almost insoluble problem, the suggestion at length came to me how it could be solved with fewer and much simpler constructions than were formally used, if some assumptions (which are axioms) were granted me. They follow in this order[1].

In this brief introduction, which I have given here in full, Copernicus makes very clear why he thinks that astronomy needs reforming. He is in principle quite happy with an epicycle-deferent model but not with the use of equants, which he sees as violating the fundamental principle of uniform circular motion, a philosophically founded astronomical axiom that he wholeheartedly accepts. The equant point is an abstract off-centre point inside the orbit of a planet, which when used as the viewing point gives the planet on its epicycle-deferent uniform motion.


equant: A sphere that is centered at the center of the universe, but whose motion varies irregularly as if it were centered at another spot, called the equant point. This geometrical tool allowed Ptolemaic astronomers to construct orbits with the observed variations of speed without resorting to the ugliness of a sphere that was actually off center (an eccentric). The Planet is actually on the outer circle below, centered at E, the center of the universe. The sphere, however, moves as if it were centered at the point marked equant below, so that it takes equal times for the planet to move from 1 to 2, from 2 to 3, from 3 to 4 and from 4 back to 1, even though the distances vary. This produces a variation in the observed speed of the planet. Source

What is interesting is that he gives no indication of the bombshell that he is about to lob into the astronomy-cosmology debate with the assumptions that he wishes to be granted by his readers. They follow immediately on the introduction. He merely wishes to substitute a heliocentric system for the universally accepted geocentric system. Even more interesting, and totally frustrating for historians of astronomy, he gives absolutely no indication whatsoever how or why he came to adopt this radical step in order to rescue the uniform circular motion axiom. Copernicus’ assumptions (axioms) read as follows[2]:

1: There is no one center of all the celestial circles or spheres.

That there is, is one of the fundamental axioms of Aristotelian cosmology

2: The center of the earth is not the center of the universe, but only of gravity and the lunar sphere

That the earth is the centre of the universe is another of the Aristotelian axioms

3: All the spheres revolve about the sun as their mid-point, and therefore the sun is the center of the universe.

Bombshell lobed without comment!

4: The ratio of the earth’s distance from the sun to the height of the firmament is so much smaller than the ratio of the earth’s radius to its distance from the sun that the distance from the earth to the sun is imperceptible in comparison with the height of the firmament.

Copernicus needs this assumption to explain the lack of observable stellar parallax. Much is made of Copernicus’ vast increase in the size of the cosmos in comparison to Ptolemaeus. However in the Almagest Ptolemaeus states, “Moreover, the earth has, to the senses, the ratio of a point to the distance of the sphere of the so-called fixed stars[3].” Even Ptolemaeus’ cosmos is in principle unimaginably large.

5: Whatever motion appears in the firmament arises not from any motion of the firmament, but from the earth’s motion. The earth together with its circumjacent elements performs a complete rotation on its fixed poles in a daily motion, while the firmament and highest heaven abide unchanged.

The concept of diurnal rotation, the earth’s daily rotation about its own axis, had been hypothesised on many occasions throughout the history of astronomy as I explained in an earlier blog post. Copernicus would call upon some of those earlier examples as support for his own views in De revolutionibus. More interesting is the phrase “together with its circumjacent elements”, where Copernicus is basically saying that the earth carries its atmosphere with it when it rotates. This counters some of the arguments already listed by Ptolemaeus against diurnal rotation. The problem for Early Modern supporters of heliocentricity or simply diurnal rotation is they lacked the physics to explain how the earth could carry its atmosphere with in on its daily spin. We will return to this topic in a later episode.

6: What appear to us as motions of the sun arise not from its motion but from the motion of the earth and our sphere, with which we revolve around the sun like any other planet. The earth has, then, more than one motion.

The first sentence merely confirms the consequences of a heliocentric model. The second states another break with the Aristotelian axioms. According to Aristotle celestial bodies have just one type of natural motion, uniform circular motion and the earth also has just one type of natural motion upward or downward perpendicular to the earth’s surface.

7: The apparent retrograde and direct motion of the planets arises not from their motion but from the earth’s. The motion of the earth alone, therefore, suffices to explain so many apparent inequalities in the heavens.

This last assumption is, of course, the biggest selling point for the adoption of a heliocentric system but in the debates following the publication of De revolutionibus, the other arguments against heliocentricity weighed so heavily that this explanation for retrograde planetary motion got largely ignored.


Second page of the Stockholm manuscript with the assumptions Source: Wikimedia Commons

Copernicus now begins to fill in the details:

            Having set forth these assumptions, I shall endeavor briefly to show how uniformity of the motions can be saved in a systematic way. However I have thought it well, for the sake of brevity, to omit from this sketch mathematical demonstrations…[4]

Once again we have a confirmation that Copernicus’ main interest, as he sees it, is to restore the uniform circular motion axiom. I shall not into detail about the rest but the section headings are:

The Order of the Spheres

The Apparent Motion of the Sun

Equal Motion Should Be Measured Not by the Equinoxes but by the Fixed Stars

The Moon

The Three Superior Planets Saturn–Jupiter–Mars



Of interest here is that some of the epicycle-deferent models he outlines here differ from those that he would later develop for De revolutionibus indicating that this is an initial concept that would undergo development in the following thirty plus years, although he announces his intention to produce a larger more detailed work in the sentence I broke off above:

However I have thought it well, for the sake of brevity, to omit from this sketch mathematical demonstration, reserving these for my larger work[6].

We have no idea how many copies of the Commentariolus Copernicus made and distributed or how many further copies were made by others. As I have indicated above there is circumstantial evidence that it was read but the lack of any direct mentions before the publication of De revolutionibus, plus the fact that there seems to have been no heliocentricity debate triggered by it, as opposed to the debate triggered by Fracastoro’s Homocentrica (1538),and a couple of other contemporary published texts on the homocentric spheres model, indicate that the Commentariolus had very little impact on the sixteenth-century astronomical community.

















[1]3 Copernican Treatises: The Commentariolus of Copernicus, The Letter Against Werner, The Narratio Prima of Rheticus, Translated with Introduction, Notes and Bibliography by Edward Rosen, Dover Publications, Inc., New York, 1959 pp. 57-58

[2]Copernicus/Rosen pp. 58-59

[3]Ptolemy’s AlmagestTranslated and Annotated by G. J. Toomer, Princeton University Press, Princeton New Jersey, ppb. 1998 p. 43

[4]Copernicus/Rosen p. 59

[5]Copernicus/Rosen pp. 59-90

[6]Copernicus/Rosen p. 59


Filed under Early Scientific Publishing, History of Astronomy, Renaissance Science, Uncategorized

Nit-picking – Authors who should know better

In my most recent reading I have come across three separate examples of professional historians making a mess of things when they turn the hand to the history of science.

First up we have Jerry Brotton’s The Renaissance: A Very Short Introduction[1]. I’m a fan of Oxford University Press’ Very Short Introduction series and also of Brotton’s A History of the World in Twelve Maps[2], so I was expecting to enjoy his Very Short Introduction to the Renaissance and in general I wasn’t disappointed.

Nit Picking001

He chooses to lay the emphasis in his book on the fact that the Renaissance wasn’t a purely European phenomenon but a global one and writing from this perspective he opens up a novel vista on this period of history. However when he turns to the history of Renaissance science he, in my opinion, drops a major clangour.

He introduces his chapter on the topic with Christopher Marlowe’s Doctor Faustus, telling us that:

Once Faustus has sold his soul, he asks Mephistopheles for a book ‘where I might see all characters and planets of the heavens’. The most controversial book that Faustus could have consulted was On the Revolutions of the Celestial Spheres by the Polish canon and astronomer Nicolaus Copernicus.[3]

We’ll ignore the Polish on this occasion and turn instead to what Brotton says about the book:

Copernicus’s revolutionary book overturned the medieval belief that the earth lay at the centre[my emphasis] of the universe. Copernicus’s vision of the heavens showed, along with all the other known planets, rotated around the sun. Copernicus subtly revised the work of classical Greek and Arabic astronomy scholars. He argued that ‘they did not achieve their aim, which we hope to reach by accepting the fact that the earth moves’.

Copernicus tried to limit the revolutionary significance of his ideas by accommodating them within a classical scientific tradition. But the Catholic Church was horrified and condemned the book. Copernicus’s argument overturned the biblical belief that the earth – and humanity with it – stood at the centre of the universe[4][my emphasis].


It was neither the biblical nor the medieval belief that the earth stood at the centre of the universe and removing the earth from this centre was not Copernicus’ offence. It was setting the earth in motion and stopping the motion of the sun that the Church found intolerable, as it contradicted several biblical passages. The myth about Copernicus displacing humanity from the centre of the universe is as far as I know and eighteenth or even nineteenth century invention and actually contradicts the medieval view of the position of the earth. The earth was not at the centre but at the bottom of the universe in the dregs. I once wrote a short blog post quoting Otto von Guericke on this subject, for those to lazy to click through:


Since, however, almost everyone has been of the conviction that the earth is immobile since it is a heavy body, the dregs, as it were, of the universe and for this reason situated in the middle or the lowest region of the heaven

Otto von Guericke; The New (So-Called) Magdeburg Experiments of Otto von Guericke, trans. with pref. by Margaret Glover Foley Ames. Kluwer Academic Publishers, Dordrecht/Boston/London, 1994, pp. 15 – 16. (my emphasis)

Need I really point out that the Church didn’t condemn De revolutionibus but in 1616 merely placed it on the Index until corrected, a procedure that was carried out with surprising rapidity. A small number of statements claiming that heliocentricity was a fact rather than a hypothesis were removed and the book approved for use by 1620.

Our next offender is another respected Renaissance historian, Andrew Pettegree, in his The Book in the Renaissance[5].

Nit Picking002

Once again this is a book that in general I find excellent and highly stimulating but like Brotton he disappoints when dealing with the history of science. Like Brotton he starts with Copernicus and De revolutionibus, he tells us:

In 1539 a young mathematician, Georg Joachim Rheticus, embarked on a journey of momentous consequence for the history of science. Rheticus is not a name well known even to scholars. At this point in his life he had little to distinguish him from other graduates at Wittenberg University apart from a family scandal: his father, a medical doctor, had been convicted of embezzlement and beheaded. In 1538 Rheticus left Wittenberg and settled in Nuremberg. Here he fell in with Johann Schoener, the city’s most distinguished astronomer: the following year he set off alone for Frauenberg, a small cathedral city on the Baltic coast beyond Danzig.

The purpose of this journey was to visit the renowned astronomer, Nicolas Copernicus. Although Copernicus had travelled in Europe earlier in his life, from 1510 he was permanently settled in his Polish-Prussian homeland, relatively remote from the major centres of European Scholarship. To ingratiate himself with the older man Rheticus had been provided with three valuable scientific volumes for Copernicus’s library. This was a gift with a purpose. The texts were the work of a Nuremberg printer, Johannes Petreius, who wanted Rheticus to persuade Copernicus to let him publish the master-work it was widely believed he would soon have ready for the press. The gift of the three texts was to demonstrate that only Germany’s greatest centre of scientific publishing could do justice to Copernicus’s work: and to help Rheticus prise the precious manuscript from the old man’s hands.

Copernicus kept Rheticus guessing. He seems to have enjoyed the younger man’s company, and it was 1541 before Rheticus could set off back to Wittenberg, clutching the manuscript of what would be Copernicus’s major text. De revolutionibus (Of the Revolution of the Heavenly Spheres). The following year he journeyed on to Nuremberg, where Petreius was waiting to set it on his press: it took until 1543 before the text, complete with its famous woodcut diagrams of Copernicus’s heliocentric system was ready for sale[6].

The story that Pettegree tells here is a very well-known one in the history of science that has been repeated, in one form or another, in numerous publications, but he still manages to get a whole series of fundamental facts wrong. Firstly, I would claim that whilst maybe not known to the general public, the name Rheticus is well-known to scholars. I think being appointed professor for the lower mathematics (i.e. arithmetic and geometry) at the University of Wittenberg in 1536 did distinguish him from other graduates of that university. He didn’t leave Wittenberg in 1538 and settle in Nuremberg but went on an official sabbatical armed with a letter of introduction written by the Rector of the university Philipp Melanchthon. One of the scholars he went to visit on that sabbatical, mentioned in that letter of introduction, was Johannes Schöner, the professor of mathematics at the Egidien Oberschule in Nürnberg a position to which he had been appointed on Melanchthon’s recommendation. Rheticus visited Schöner almost certainly to study astrology, a subject dear to Melanchthon’s heart.

Copernicus lived in Warmia (Ermland in German) an autonomous self governing Prince Bishopric. Rheticus took not three but six books as a gift to Copernicus of which four had been printed and published by Petreius in Nürnberg. When Rheticus visited Copernicus he was largely unknown and to describe him as renowned is more than a bit of a stretch. His renown came posthumously following the publication of De revolutionibus. There were rumours of a hypothesis and possibly a book, rumours created by the circulating manuscript of the Commentariolus but to state that Petreius or anybody else for that matter outside of Warmia knew of a master-work that would soon be ready for the press is once again an exaggeration. Rheticus’ mission could better be described as look see if Copernicus has anything substantial that could be of interest to a printer publisher specialised in astrological/astronomical and mathematical texts.

Copernicus did not keep Rheticus guessing. Firstly Rheticus suffered a period of illness and then travelled to Königsberg, where he wrote a chorography of Prussia for Duke Albrecht in 1541. Copernicus was reluctant to present his hypothesis to the world because he knew that he could not fulfil the promise that he had given in the Commentariolus that he would prove his hypothesis. To calm his fears Rheticus wrote and published his Narratio Prima in 1540 in Danzig, with a second edition appearing in Basel in 1541. This presented a brief first account of the heliocentric system and its positive reception convinced Copernicus to entrust Rheticus with his manuscript.

All in all a more than somewhat different story to that present to us by Pettegree

Next up we have my current bedtime reading Michael Bravo’s North Pole: Nature and Culture[7], which I’m enjoying immensely.

Nit Picking003

Although the emphasis of the book is on the polar voyages and expeditions beginning in the modern period the book starts much earlier. The first chapter contrasts the views of the North Pole of the ancient Greek astronomers, who saw it as the downwards extension of the North celestial pole and the Inuit who live/lived in the Arctic. The second chapter deals with the representations of the North Pole made by the cartographers and globe makers of the Early Modern Period, a topic of great interest to me, as regular readers will know. It is here that Bravo displays a surprising lack of accurate research. He tells us:

Apian was fortunate to have studied in nearby Vienna, introducing him to the work of a circle of highly talented mathematicians in Nuremberg, Ingolstadt and Vienna who were working under the patronage of Maximilian I, Holy Roman Emperor (1459–1519)…[8]

This is indeed correct and is something that I have written about in several posts and about which Darin Hayton has written a whole book, his The Crown and the Cosmos: Astrology and the Politics of Maximilian I, which I reviewed here. Bravo then goes on to discuss the Werner-Stabius cordiform map projection, which is of course a polar projection centred on the North Pole. All well and good up till now. After an extensive discussion of the cordiform projection, its use and its impact Bravo goes on to say:

Introducing the perspective of viewing the Earth from above brought cosmography into line with the new developments in drawing, projection and perspective pioneered in Renaissance Europe. Albrecht Dürer (1471-1528), one of the most remarkable German artists, was the son of a prominent goldsmith in Nuremberg. Dürer’s precocious talent for drawing broadened into printmaking, writing and an extraordinary rich span of philosophical interests. His studies of perspective spanned much of his life and he brought back to northern Europe the principles of linear perspective he encountered while studying in Bologna. He later moved to Vienna to work with Stabius and Werner under the patronage of Maximilian I[my emphasis] Dürer and Stabius published the first polar star chart in 1515[9].


As a Dürer fan, it’s nice to see him getting a nod for more than his Rhinoceros and yes Maximilian was one of his patrons, but the sentence I have placed in italics manages to include two major errors in just sixteen words. Firstly if Dürer had moved to Vienna, he would have only met Stabius and not Werner. The two knew each other from their mutual time at the University of Ingolstadt in the early 1480s but whereas Werner moved first to Rome and then to Nürnberg on the completion of his studies, Stabius stayed in Ingolstadt eventually becoming professor of mathematics before moving to Vienna as court historian and mathematician on Conrad Celtis’ Collegium poetarum et mathematicorum. The two of them continued to work together not by being in the same city but through correspondence. Needless to say Dürer never left Nürnberg and never moved to Vienna, his various shared projects with Stabius were either conducted by letter or by Stabius journeying to Nürnberg. I should point out the Dürer-Stabius-Heinfogel star maps were not the first polar star charts but the first European printed polar star charts, there are earlier manuscript ones and also earlier printed Chinese ones.

All of the things that I have criticised above are facts that are comparatively easy to find and verify with a relatively small amount of research work, so there really is no excuse for getting them wrong. It would be bad enough if the authors were beginners, amateurs or wanna be historians. But in each case we have to do with a justifiably renowned historian and author, so there is really no excuse for this level of sloppiness.

[1] Jerry Brotton, The Renaissance: A Very Short Introduction, OUP, Oxford, 2006

[2]Jerry Brotten, A History of the World in Twelve Maps, Allen Lane, London, 2012

[3] Brotton p. 99

[4] Brotton p. 99

[5] Andrew Pettegree, The Book in the Renaissance, Yale University Press, New Haven & London, 2011

[6] Pettegree pp. 273–274

[7]Michael Bravo, North Pole: Nature and Culture, Reaktion Books, London, 2019

[8] Bravo p. 56

[9] Bravo p. 60


Filed under History of Astronomy, History of Cartography, History of science, Renaissance Science

The emergence of modern astronomy – a complex mosaic: Part V

Part I Part II Part III Part IV

As I already mentioned in Part II, Copernicus wrote his first work on his heliocentric theory in about 1510, the Commentariolus, which remained in manuscript but seems to have enjoyed a fairly wide distribution, as we will see later. However, Copernicus was not the only show in town in the astronomical world of the sixteenth century. Before I continue with his story I will look at what else of significance was taking place.

In Part I we learnt how Toscanelli took a new approach in his treatment of comets, viewing them as objects to be astronomically observed and not just as meteorological phenomena as the Aristotelian had; his lead was followed in Vienna by Peuerbach and Regiomontanus. In the 1530s there was a series of spectacular comets, which attracted the attention of the new class of European astronomers and their observations led to more new developments.


Girolamo Fracastoro (c. 1477–1553) was the first European to draw attention to the fact that a comets tail always points away from the sun in his Homocentrica (1538); a seemingly trivial discovery but one that correctly interpreted played an important role in re-determining the role of comets.


Portrait of Girolamo Fracastoro by Titian, c.1528 Source: Wikimedia Commons

Peter Apian also independently the same discovery in his Astronomicum Caesareum (1540). Strangely the discovery is usually only attributed to Apian.


Apian’s depiction of comet’s tail facing away from the sun Source: Wikimedia Commons

The Fracastoro/Apian discovery had been made much earlier by the Chinese but this was not known in Europe. Johannes Schöner was stimulated by the situation to publish Regiomontanus’ work on determining the parallax of a moving comet, a problem that was taken up again in a correspondence between John Dee and Tycho Brahe later in the century. Comets were no longer just astrological harbingers of doom but had become objects of astronomical interest.

In a European wide debate that included Copernicus, amongst others, both Gerolamo Cardano in Milan and Jean Pena, Royal Professor of Mathematics in Paris, came up with a new comet concept. Comets were supralunar and transparent; they functioned like a lens that focused the sunlight, the focused light being then the tail of the comet. A serious breach had been made in the accepted Aristotelian cosmology. Not only were comets supralunar but they were also supralunar object that demonstratively changed, an affront for the Aristotelian concept of a perfect, unchanging heaven.

Of course, these new radical ideas were not instantly accepted by the European astronomical community and it was a community, which discussed and debated their observations and theories with each other. However, it stimulated that community to plan observation programmes to be carried out the next time comets would appear in the heavens over Europe. Unfortunately, when the next spectacular comet appeared over Europe in 1556, one generation of capable astronomers was already dead and the next one was still in its childhood (Tycho was ten and Mästlin was six years old) or in the case of Kepler not yet born.

PII: 0160-9327(79)90035-8

An astronomical broadsheet by Paul Fabricius, showing the map of the 1556 comet’s course Source: Wikimedia Commons

Urania was, however generous, delivering a supernova in 1572 and a great comet in 1577 for the delectation of the eager European community of astronomers.


Red circle upper left hand corner remnant of 1572 supernova Source: Wikimedia Commons

The discovery, observation and analysis of these celestial phenomena are, in the popular history of astronomy books, almost exclusively attributed to Tycho Brahe. This attribution creates a distorted picture of what actually happened. Astronomers, amateur and professional, all over Europe observed both the supernova and the comet, attempted to determine parallax and thus the distance of them and wrote up and published their results and opinions is a veritable flood of publication, largely pamphlets.

The results covered a wide spectrum, from definitely supralunar over non-measurable parallax to definitely sublunar. Tycho, Michael Mästlin and Thaddaeus Hagecius ab Hayek (1525–1600), all influential astronomers, all determined that the observed phenomena were clearly supralunar. For those who have not come across him Thaddaeus Hayek was professor of mathematics at the University of Prague and personal physician to the Holy Roman Emperor Rudolf II and played a central role in bringing both Tycho and Johannes Kepler to Rudolf’s Court in Prague.


Thaddaeus Hagecius ab Hayek Source: Wikimedia Commons

In the acceptance of the fact that the celestial phenomena of the 1570s were supralunar and thus demolished a large chunk of Aristotelian cosmology i.e. that he heaven are perfect and unchanging, at the time, Mästlin’s word counted more than Tycho’s but the placet of widespread acceptance was lent to this opinion through its confirmation by the leading Catholic astronomer, Christoph Clavius (1538–1612). We will return to the role of comets in the emergence of modern astronomy in a later post but before I depart here I want to comment on the categorical rejection of the supralunar nature of the supernova of 1572 and the comet of 1577 by the Nürnberger artist and astrologer/astronomer Georg Busch (ca. 1530–1579).

Born in Nürnberg, Busch moved to Erfurt where he worked as an artist and from about 1550 as an astrologer/astronomer. Busch published two books on the 1572 supernova, which he consistently referred to as a comet: Von den Comet, welcher in diesem 1572. Jar in den Monet Novembris erschienen, Erfurt, 1572 (On the Comet, which appeared in this Year of 1572 in the Month of November) and Entschuldingung and Schutzrede Georgij Busch… Erfurt, 1573 (Apology and Defence of Georg Busch…(the title goes on and on). The second pamphlet is a defence against criticism. Both publications went through several editions showing that the ‘modern’ astronomers didn’t by any means have the field to themselves. Busch’s publications even made it into Tycho’s annotated catalogue of the comet publications. What I personally love is Busch’s description of the nature of comets:

“…the comet was composed of a sort of obnoxious gas generated by human sin, which floated heavenward until ignited by the wrath of God. As it burned the comet became a prolific celestial polluter, showering its effluence widely over Earth and thereby causing pestilence, Frenchmen, sudden death, bad weather…”

Observant readers might have noticed that Fracastoro’s account of the direction of comet’s tails was in a book entitled Homocentrica.

The central argument of this publication was a rejection of the epicycle-deferent model of Ptolemaeus and a return to the homocentric spheres model of the cosmos propagated by Eudoxus and above all Aristotle. This is, of course, highly reactionary in the sixteenth century when most important astronomers were moving away from Aristotelian orthodoxy but Fracastoro was a well-known and highly respected author so his opinion was by no means rejected out of hand. Later in the century Christoph Clavius (1538–1612), the defender in chief of Ptolemaic astronomy, regarded Fracastoro’s homocentricity as a greater threat than Copernicus’ heliocentricity.

It should be clear that far from representing a boring, orthodox conformity that was shaken out of its torpid stupor by Copernicus publishing his heliocentric hypothesis, the sixteenth century debate on astronomy and cosmology was a lively exchange of ideas and concepts some old and some new.









Filed under History of Astronomy, History of science, Renaissance Science

The emergence of modern astronomy – a complex mosaic: Part IV

Part I  Part II Part III

There is general agreement amongst historians of science that a major factor in the emergence of modern science in general and modern astronomy in particular was the (re)invention of moveable type printing and the arrival of the printed book in the middle of the fifteenth century. I say reinvention because moveable type printing emerged twice before in China in the eleventh century CE and in Korea in the fourteenth century, as I explained in an earlier post. For a long time it was a commonplace in the historical narrative that the printed book, like gunpowder and the compass, was a Chinese invention but extensive long-term research has failed to produce any evidence of a technology transfer and it is now thought that Johannes Gutenberg’s was an independent invention. Even within Europe Gutenberg was not the first to experiment with moveable type and his real invention was the printing press, inclusive printing ink.


Book Printers from Jost Amman  Professionals and Craftsmen

Less than twenty years after Gutenberg published his Bible, Regiomontanus printed and published the first printed astronomy book Peuerbach’s Theoricae Novae Planetarum (Nürnberg, 1473) followed by a handful of other astronomy/astrology books. Unfortunately he died before he could publish their Epytoma in almagesti Ptolemei, which was first published by Ratdolt in Venice in 1496. Both titles became standard astronomy textbooks throughout Europe for more than one hundred years. Famously also being the texts from which Copernicus learnt his astronomy and cosmology.


Theoricae Novae Planetarum Source: Wikimedia Commons

This marked the start of a wave of printed astronomy/astrology books throughout the sixteenth and seventeenth centuries including the works of Apian, Copernicus, Tycho, Kepler, Galileo and many other less well-known figures. Printing made reliable, consistent text available to a wide circle of readers. Whereas a copy of a manuscript in Copenhagen might well have serious deviations compared with a manuscript of the same work in Venice, printed copies of a book were in theory the same wherever their owners lived and worked.


The Astronomer from Jost Amman’s Professionals and Craftsmen Source: Wikimedia Commons

As I pointed out in a reply to an earlier comment in this series the printed great works of astronomy, such as Copernicus’ De revolutionibusor Apian’s Astronomicum Caesareum, would have been way beyond the pocket of the average university student of the period but the professional astronomers, their patron and the institutions could and did acquire copies thus making them, at least potentially, accessible to those students. Interestingly Kepler bought a second hand copy of Copernicus’ De revolutionibus when he was still a student.

However, printing advanced the general dissemination and progress of astronomy and its related fields through purpose written textbooks. The most obvious example of this is Peter Apian’s Cosmographia, originally published by the author in Landshut in 1524. This was a basic introduction to astronomy, astrology, surveying, cartography etc. In total, over the sixteenth century, the book went through thirty-two expanded and improved editions all of which were, somewhat strangely, edited and published by Gemma Frisius and not Apian. Similar textbooks were produced by Oronce Fine, Michael Mästlin and many other sixteenth century mathematical authors.


Title page of Apian’s Cosmpgraphia

It was not just major monographs that profited from the invention of movable type printing. Such astronomical/astrological tools as ephemerides benefited from a certain level of consistency given by print as opposed to hand written manuscripts with their copying errors. In fact a large part of Regiomontanus’ posthumous reputation was based on his printed ephemeris, one of the few books he was able to publish before his untimely demise.

Regiomontanus also led the way in producing printed astronomical/astrological calendars, volumes much in demand from all those working in the wider field of astronomy. In fact astronomical/astrological ephemera of all types–calendars, prognostica, single-sheet wall calendars, almanacs–became a mainstay of the early printing industry providing a much need flow of ready cash.


Regiomontanus Calendar Source: University of Glasgow

To give an idea of the scope of this activity, one of the calendars of Simon Marius (1573–1625), which had to be withdrawn because of political complaints by the local authorities, was said by the printer publisher to have had an edition of 12,000. Marius was only a small local astrologer; the editions of the calendars and prognostica of an Apian or a Kepler would have been much larger. An astronomical monograph, such as De revolutionibus, would have had high production costs and an edition of maybe 500. It would take several years before it turned a profit for the printer publisher if at all. The author got nothing for his troubles. A calendar (wall or pocket), prognostica or almanac had comparatively low production costs, a large edition and if the author was established sold very rapidly. The profits were usually shared fifty-fifty between the printer and the author, a reliable stream of income for both parties. Gutenberg raised some of the finance for his Bible by printing and issuing an astro-medical single-sheet wall calendar.

In an important work, Astrology and the Popular Press: English Almanacs 1500–1800historian Bernard Capp showed that astrological ephemera made up by far and away the largest sector of publishing in the early centuries of printing and more importantly that the editorial sections of the cheap almanacs were one of the major sources for disseminating the latest developments in astronomy, in particular, in the seventeenth century, heliocentricity.


Almanack by John Tulley, 1692. Book exhibited in the Cambridge Public Library, Cambridge, Massachusetts Source: Wikimedia Commons

Along with the development of moving type printing came an increased use of illustrations leading to a rapid development in the techniques used to produce them–woodblock printing, copperplate engraving and etching.


Woodblock cutter Jost Amman’s Professionals and Craftsmen Source: Wikimedia Commons

These techniques were then extended to other field related to astronomy, cartography and globe making. Printed copies of Ptolemaeus’ Geographia with maps were already being printed in the last quarter of the fifteenth century. There also quickly developed a market for large scale printed wall maps, the most famous early example being Waldseemüller’s world map that gave the very recently discovered fourth part of the world the name America after Amerigo Vespucci (1454–1512). Waldseemüller also seems to have printed the first terrestrial globe, a small globe containing the same map of the world. Unfortunately we only have a small number of printed globe gores and no surviving finished globes.


Waldseemüller World Map 1507 (Wikipedia Commons)

Johannes Schöner (1477–1547) was the first to start producing serial printed globes, his first terrestrial globe in 1515 and the matching celestial globe in 1517, establishing a tradition for matching pairs of printed globes that continued until the end of the nineteenth century. Judging by comments from his correspondence his globe printing enterprise was both very successful and very lucrative. Gemma Frisius (1508–1555) took up the baton producing printed globes to be sold with reprints of Schöner’s cosmographia, the descriptive book sold with each globe to explain how to use it. Gemma’s assistant was Gerhard Mercator, who would go on to become the most successful printed globe maker of the second half of the sixteenth century. Mercator’s globes inspired both the great Dutch cartographical houses of Hondius and Blaeu, who would dominate the European globe making and cartography industry in the seventeenth century. England’s first commercial globe printer, Joseph Moxon (1627–1691) learnt his handwork from Willem Janszoon Blaeu (c. 1570–1630). Printed globe making was big business in the sixteenth and seventeenth centuries and the globes were used to teach both astronomy and astrology.


Pair of globes by Gerard Mercator (Globe Museum, Austrian National Library).

Of course all of the above applies equally well to printed maps. Along with the demand for large wall maps, a market developed for collections of printed maps, what we now call atlases. Bound collection of manuscript maps existed before the invention of printing but being the product of hundreds of hours of manual labour these tended to be art treasures for rich patrons rather than practical books for everyday usage. The man, who did most to change this was Abraham Ortelius (1527–1598), whose Theatrum Orbis Terrarum, a bound, standardised, collection of maps, produced especially for traders first published in 1570 was a runaway success. Initial less successful was the more academic Atlas of his good friend and rival Gerhard Mercator. However, both publications laid the foundations for the commercial success of the cartographical publications of Blaeu and Hondius.


Theatrum Orbis Terrarum Title Page Source: Wikimedia Commons

A somewhat different approach was taken by Sebastian Münster (1488–1552), with his Cosmographia, first published in 1544, which was not just a collection of maps but also a full geographical and historical description of the world. In its numerous editions it was almost certainly the biggest selling book in the sixteenth century.


Title page of the first edition of Münster’s Cosmographia Source: Wikimedia Commons

Like nearly-all-the-other globe makers and cartographers described here Münster was an astrologer and astronomer. Other astrologer/astronomers in the sixteenth century, who were also commercially successful as cartographers were Peter and Philipp Apian, Oronce Fine and Michael Mästlin.

It should be clear from the above that the advent of movable type printing had a very large impact on the dissemination of astronomy and its related fields at the same time raising its status in the Early Modern Period in Europe and bringing it to a much wider audience.


Filed under Early Scientific Publishing, History of Astrology, History of Astronomy, History of Cartography, Renaissance Science, Uncategorized

An important 13th-century book on optics

The thirteenth-century Silesian friar and mathematician Witelo is one of those shadowy figures in the history of science, whose influence was great but about whom we know very little.


Page from a manuscript of Perspectiva with a miniature of the author Source: Wikimedia Commons

His biography can only be pieced together from scattered comments and references. In his Perspectiva he refers to “our homeland, namely Poland” and mentions Vratizlavia (Wroclaw) and nearby Borek and Liegnitz suggesting that he was born in the area. He also refers to himself as “the son of Thuringians and Poles,” which suggests his father was descended for the Germans of Thuringia who colonized Silesia in the twelfth and thirteenth centuries and his mother was of Polish descent.

A reference to a period spent in Paris and a nighttime brawl that took place in 1253 suggests that he received his undergraduate education there and was probably born in the early 1230s. Another reference indicates that he was a student of canon law in Padua in the 1260s. His Tractatus de primaria causa penitentie et de natura demonum, written in Padua refers to him as “Witelo student of canon law.” In late 1268 or early 1269 he appears in Viterbo, the site of the papal palace. Here he met William of Moerbeke  (c. 1220–c. 1286), papal confessor and translator of philosophical and scientific works from Greek into Latin. Witelo dedicated his Perspectiva to William, which suggest a close relationship. This amounts to the sum total of knowledge about Witelo’s biography.

In the printed editions of the Perspectiva he is referred to as Vitellio or Vitello but on the manuscript copies as Witelo, which is a diminutive form of Wito or Wido a common name in thirteenth century Thuringia, so this is probably his correct name. Family names were uncommon in thirteenth-century Poland, and there is no evidence to suggest that Witelo had one.[1]

Witelo’s principle work, his Perspectiva, was not started before 1270, as he uses William of Moerbeke’ translation of Hero of Alexandria’s Catoptrica, which was only completed on 31stDecember 1269. Witelo is one of three twelfth century authors, along with Roger Bacon (c. 1219–c. 1292) and John Peckham (c. 1230–1292), who popularised and disseminated the optical theories of  Abū ʿAlī al-Ḥasan ibn al-Ḥasan ibn al-Haytham, known in Latin as Alhazen or Alhacen. Al-Haytham’s Kitāb al-Manāzir (Book of Optics) was the most important Islamic texts on optics and one of the most important in the whole history of optics. It was translated into Latin by an unknown translator in the late twelfth or early thirteenth century with the title De aspectibus. Bacon was the first European author to include De aspectibus in his various writings on optics and Witelo and Peckham followed his lead. Although it is clear that Witelo used Ptolemy’s Optica, Hero’s Catoptrica and the anonymous De speculis comburentibus in composing his Perspectiva, and that he was aware of Euclid’s Optica, the Pseudo-Euclid Catoptrica and other prominent works on optics, it is very obvious that his major debt is to al-Haytham’s De aspectibus, although he never mentions him by name.

The Perspectiva is a monumental work that runs to nearly five hundred pages in the printed editions. It is divided into ten books:

Book I: Provides the geometric tools necessary to carry out geometrical optics and was actually used as a geometry textbook in the medieval universities.

Book II: Covers the nature of radiation, the propagation of light and colour, and the problem of pinhole images.

Book III: Covers the physiology, psychology, and geometry of monocular and binocular vision by means of rectilinear radiation.

Book IV: Deals with twenty visible intentions other than light and colour, including size, shape, remoteness, corporeity, roughness darkness and beauty. It also deals with errors of perception.

Book V: Considers vision by reflected rays: in plane mirrors

Book VI: in convex spherical mirrors

Book VII: in convex cylindrical and conical mirrors

Book VIII: in concave spherical mirrors

Book IX: in concave cylindrical, conical, and paraboloidal mirrors

Book X: Covers vision by rays refracted at plane or spherical surfaces; it also includes a discussion of the rainbow and other meteorological phenomena.

Witelo’s Perspectiva became a standard textbook for the study of optics and, as already mentioned above, geometry in the European medieval universities; it was used and quoted extensively in university regulations right down to the seventeenth century. The first printed edition of this important optics textbook was edited by Georg Tannstetter (1482–1535) and Peter Apian (1495–1552) and printed and published by Johannes Petreius (c. 1497–1550) in Nürnberg in 1535 under the title Vitellionis Mathematici doctissimi Peri optikēs, id est de natura, ratione & proiectione radiorum visus, luminum, colorum atque formarum, quam vulgo perspectivam vocant.


Georg Tannstetter Portrait ca. 1515, by Bernhard Strigel (1460 – 1528) Source: Wikimedia Commons

Georg Tannstetter born in Rain am Lech in Bavaria had studied at the University of Ingolstadt under Andreas Stiborius (c. 1464–1515) and when Stiborius followed Conrad Celtis (1459–1508) to Vienna in 1497 to become professor for mathematics on the newly established Collegium poetarum et mathematicorum Tannstetter accompanied him. In 1502 he in turn began to lecture on mathematics in Vienna, the start of an illustrious career.


Conrad Celtis: Gedächtnisbild von Hans Burgkmair dem Älteren, 1507 Source: Wikimedia Commons

Peter Apian, possibly his most famous pupil, was born, Peter Bienewitz, in Leisnig. He entered the University of Vienna in 1519 graduating B.A. in 1521. He then moved first to Regensburg and then to Landshut where he began his publishing career with his Cosmographicus liber in 1524.


Apianus on a 16th-century engraving by Theodor de Bry Source: Wikimedia Commons

Following several failed attempts to acquire the position, Apian was appointed printer to the University in Ingolstadt in 1527, as well as lecturer for mathematics, positions he would hold until his death in 1552, when he was succeeded by his son Philipp (1531–1589), who had begun to take over his teaching duties before his death.

Apian’s Ingolstadt printing office continued to produce a steady stream of academic publications, so it comes as somewhat of a surprise that he chose to farm out the printing and publication of his own Instrumentum primi mobilis (1534) and the Tannstetter/Apian edited Witelo Perspectiva (1535) to Johannes Petreius in Nürnberg. Although both books were large and complex it should have been well within Apian’s technical capabilities to print and publish them in his own printing office; in 1540 he printed and published what is almost certainly the most complex science book issued in the sixteenth century, his Astronomicon Caesareum. The problem may have been a financial one, as he consistently had problems getting the university to supply funds to cover the advance cost of printing the books that he published.


Source: Wikimedia Commons

Johannes Petreius, actually Hans Peter, was born in the Lower Franconian village of Langendorf near Hammelburg. He studied at the university in Basel graduating MA in 1517. Here he also learnt the printing trade in the printing office of his uncle Adam Petri (1445–1527). In 1523 he moved to Nürnberg where he set up his own printing business. By the early 1530s, when Apian approached him, he was one of the leading German printer publishers with a good reputation for publishing mathematical works, although his most famous publication Copernicus’ De revolutionibus orbium coelestium still lay in the future. In fact his publishing catalogue viewed as a whole makes him certainly the most important printer publisher of mathematical books in Germany and probably in the whole of Europe in the first half of the sixteenth century. As was his style he produced handsome volumes of both Apian’s Instrumentum and Witelo’s Perspectiva.


Apian’s Instrumentum Title Page Source: Sothebys

Although he died in 1550 the Petreius printing office would issue an unchanged second edition of the Witelo in 1551, which was obviously in preparation before his death. After his death his business ceased as he had no successor and his catalogue passed to his cousin Heinric Petri (1508–1579) in Basel.


Vitellionis Mathematici doctissimi Peri optikēs… title page Source: Christie’s

The Witelo volume would come to play a role in the eventual publication of Copernicus’ magnum opus by Petreius. When Georg Joachim Rheticus (1514-1574) set out in 1539 to seek out Copernicus in Frombork he took with him the Witelo tome as one of six specially-bound-as-a-set books, four of which had been printed and published by Petreius, as a gift for the Ermländer astronomer. The Petreius books were almost certainly meant to demonstrate to Copernicus what Petreius would do with his book if he allowed him to print it. The mission was a success and in 1542 Rheticus returned to Nürnberg with Copernicus’ precious manuscript for Petreius to print and publish in 1543.


Copernicus De revolutionibus title page Source: Wikimedia Commons

There was a third printed edition of Witelo’s Perspectiva printed and published from a different manuscript by Friedrich Risner (1533–1580) together with al-Haytham’s De aspectibus in a single volume in Basel in 1527 under the title, Opticae thesaurus: Alhazeni Arabis libri septem, nuncprimum editi; Eiusdem liber De Crepusculis et nubium ascensionibus, Item Vitellonis Thuringopoloni libri X.


Friedrich Risner edition Opticae Thesaurus (Basel, 1572) Title Page Source

This is the edition that Johannes Kepler (1571–1630) referenced in his Astronomiae pars optica. Ad Vitellionem Paralipomena (The Optical Part of Astronomy: Additions to Witelo) published in Prague in 1604, the most important book on optics since al-Haytham’s.


Astronomiae pars optica. Ad Vitellionem Paralipomena  Source: University of Reading

Witelo remains an obscure thirteenth century scholar but his optics magnum opus cast a shadow down more than four hundred years of European history of optics. [2]

[1]All of the biographical information, and mush else in this article, is taken from David C. Lindberg, Witelo in Complete Dictionary of Scientific Biography, Charles Scribner’s Sons, 2008. Online at

[2]For more on Witelo’s influence on the history of optics see David C. Lindberg, Theories of Vision from al-Kindi to Kepler, University of Chicago Press, Chicago and London, 1976, ppb. 1981.

On Peter Apian as a printer Peter Apian: Astronomie, Kosmographie and Mathematik am Beginn der Neuzeit mit Ausstellungskatalog, ed. Karl Röttel, Polygon-Verlag, Buxheim, Eichstätt, 1995 and Karl Schottenloher, Die Landshunter Buchdrucker des 16. Jahrhundert. Mit einem Anhang: Die Apianusdruckerei in Ingolstadt, Veröffentlichungen der Gutenberg-Gesellschaft XXXI, Mainz, 1930


Filed under Early Scientific Publishing, History of Astronomy, History of Mathematics, History of Optics

The emergence of modern astronomy – a complex mosaic: Part III

You can read Part I here and Part II here

Although I dealt with the special case of Vienna and the 1st Viennese School of Mathematics in the first post of this series, it is now time to turn to the general history of the fifteenth-century university and the teaching of astronomy. Although the first, liberal arts, degree at the medieval university theoretically encompassed the teaching of the quadrivium, i.e. arithmetic, geometry, music and astronomy, in reality the level of teaching was very low and often neglected all together. Geometry was a best the first six books of Euclid and at worst just book one and astronomy was the Sphaeraof Sacrobosco, a short non-technical introduction.

This all began to change in the fifteenth century. The humanist universities of Northern Italy and of Poland introduced dedicated chairs for mathematics, whose principle purpose was the teaching of astrology to medical students. However, to fully understand astrology and to be able to cast horoscopes from scratch students first had to learn astronomy, which in turn entailed first having to learn arithmetic and geometry, as well as the use of mathematical and astronomical instruments. The level of mathematical tuition on the university increased considerable. The chairs for mathematics that Galileo would occupy at the end of the sixteenth century in Pisa and Padua were two such astrology chairs.

As the first European university, Krakow introduced two such chairs for mathematics and astronomy relatively early in the fifteenth century.


The founding of the University of Krakow in 1364, painted by Jan Matejko (1838–1893) Source: Wikimedia Commons

It was here at the end of the century  (1491–1495) that Copernicus first learnt his astronomy most probably in the lectures of Albert Brudzewski (c. 1445–c.1497) using Peuerbach’s Theoricae Novae Planetarum and Regiomontanus’ Astronomical Tables. Brudzewski also wrote an important commentary on Peuerbach’s Theoricae Novae Planetarum,Commentum planetarium in theoricas Georgii Purbachii (1482).Krakow was well endowed with Regiomontanus’ writings thanks to the Polish astrologer Marcin Bylica (c.1433–1493), who had worked closely with Regiomontanus on the court ofMatthias Corvinus (1443–1490) in Budapest and who when he died bequeathed his books and instruments to the University of Krakow, including the works of Regiomontanus and Peuerbach.

From Krakow Copernicus went on to Northern Italy and its humanist universities. Between 1496 and 1501 he studied canon law in Bologna, Europe’s oldest university.


The entry of some students in the Natio Germanica Bononiae, the nation of German students at Bologna; miniature of 1497. Source: Wikimedia Commons

Here he also met and studied under/worked with the professor for astronomer Domenico Maria Novara da Ferrara (1454–1504), who claimed to be a student of Regiomontanus and it is known that he studied under Luca Pacioli (c. 1447–1517), who was also Leonardo’s mathematics teacher. Although none of Novara da Ferrara writings have survived he is said to have taken a critical attitude to Ptolemaic astronomy and he might be the trigger that started Copernicus on his way. In late 1501 Copernicus moved to the University of Padua, where he studied medicine until 1503, a course that would also have included instruction in astrology and astronomy. In 1503 he took a doctorate in canon law at the University of Ferrara. Sometime in the early sixteenth century, probably around 1510 he wrote an account of his first thoughts on heliocentricity, now known as the Commentariolus, which was never published but seems to have circulated fairly widely in manuscript. We will return to this later.

The first German university to install a dedicated chair for mathematics/astronomy was Ingolstadt in the 1470s.


The Hohe Schule (High School), The main building of the University of Ingolstadt 1571 Source: Wikimedia Commons

As with the North Italian universities this was principally to teach astrology to medical student. This chair would prove to be an important institution for spreading the study of the mathematical sciences. In 1491/1492 the humanist scholar and poet, Conrad Celtis (1459–1508) was appointed professor of poetics and rhetoric in Ingolstadt. Celtis had a strong interest in cartography as a part of history and travelled to Krakow in 1489 in order to study the mathematical sciences. In Ingolstadt Celtis was able to turn the attention of Andreas Stiborius (1464–1515) and Johannes Stabius (1468–1522) somewhat away from astrology and more towards cartography. In 1497 Celtis received a call from the University of Vienna and taking Stiborius and Stiborius’ star student Georg Tannstetter (1482–1535) with him he decamped to Vienna, where he set up his Collegium poetarum et mathematicorum, with Stiborius as professor for mathematics. In 1502 he also fetched Johannes Stabius. From 1502 Tannstetter also began to lecture on mathematics and astronomy in Vienna. Stiborius, Stabius and Tannstetter form the foundations of what is known as the 2ndViennese School of Mathematics. Tannstetter taught several important students, most notably Peter Apian, who returned to Ingolstadt as professor for mathematics in the 1520, a position in which he was succeeded by his son Philipp. Both of them made major contributions to the developments of astronomy and cartography.

Stabius’ friend and colleague Johannes Werner also studied in Ingolstadt before moving to and settling in Nürnberg. One of the few astronomical writing of Copernicus, apart from De revolutionibus, that exist is the so-called Letter against Werner in which Copernicus harshly criticised Werner’s Motion of the Eighth Sphere an essay on the theory of precession of the equinox.

Another graduate of Ingolstadt was Johannes Stöffler (1452–1531), who having had a successful career as an astronomer, astrologer and globe and instrument maker was appointed the first professor of mathematics at the University of Tübingen.


The Old Auditorium University of Tübingen Source: Wikimedia Commons

Amongst his student were Sebastian Münster (1488–1552) the most important cosmographer of the sixteenth century and Philipp Melanchthon (1497–1560), who as a enthusiastic fan of astrology established chairs for mathematics and astronomy at all of the protestant schools and universities that he established starting in Wittenberg, where the first professor for lower mathematic was Jakob Milich (1501–1559) another graduate of the University of Vienna. Milich’s fellow professor for astronomy in Wittenberg Johannes Volmar (?–1536), who started his studies in Krakow. The successors to Milich and Volmar were Georg Joachim Rheticus (1514–1574) and Erasmus Reinhold (1511–1553).

Another Melanchthon appointment was the first professor for mathematics on the Egidien Obere Schule in Nürnberg, (Germany’s first gymnasium), the globe maker Johannes Schöner (1477–1547), who would play a central role in the heliocentricity story. Schöner had learnt his mathematics at the university of Erfurt, one of the few German universities with a reputation for mathematics in the fifteenth century. When Regiomontanus moved from Budapest to Nürnberg he explained his reasons for doing so in a letter to the Rector of Erfurt University, the mathematician Christian Roder, asking him for his active support in his reform programme.

The Catholic universities would have to wait for Christoph Clavius (1538–1612) at the end of the sixteenth century before they received dedicated chairs for astronomy to match the Lutheran Protestant institutions. However, there were exceptions. In Leuven, where he was actually professor for medicine, Gemma Frisius (1508–1555) taught astronomy, astrology, cartography and mathematics. Amongst his long list of influential pupils we find Johannes Stadius (1527–1579), Gerhard Mercator (1512–1594) and John Dee (1527–1609). In France, François I appointed Oronce Fine (1494–1555) Royal lecturer for mathematics at the University of Paris. He was not a very impressive mathematician or astronomer but a highly influential teacher and textbook author. In Portugal, Pedro Nunes (1502–1578) was appointed the first professor of mathematics at the university of Coimbra as well as to the position of Royal Cosmographer.


The University of Coimbra Palace Gate. Source: Wikimedia Commons

Over the fifteenth and sixteenth centuries the mathematical sciences, driven mainly by astrology and cartography, established themselves in the European universities, where the professors and lecturers, as we shall see, played a central role in the reform and renewal of astronomy.








Filed under History of Astrology, History of Astronomy, History of Cartography, History of medicine, Renaissance Science