Category Archives: Renaissance Science

Physicians to the fore – creating a new medical hierarchy in the Early Modern Period

People with only a minimal knowledge of the history of medicine might be forgiven for automatically thinking of doctors when talk turns to medical consultation, diagnosis and treatment in earlier ages. However in the High Middle Ages and down into the Renaissance physicians, barber surgeons, apothecaries, midwifes, herbalist all competed with each other for patients, in particular the university educated physicians and apothecaries were rivals. In the Early Modern Period the physicians set a campaign in motion to create a medical hierarchy with themselves at the top able to dictate to the other practitioners. Historian of medicine Hannah Murphy has written an excellent volume describing this process of social change in the world of medicine in Reformation Nuremberg, A New Order of Medicine: The Rise of Physicians in Reformation Nuremberg[1]


The introduction to Murphy’s is titled Inventing Medical Reform and starts with Joachim Camerarius’ Short and Ordered Considerations for the Formation of a Well-Ordered Medicine (1571) outlining his proposed reform of medicine in the city of Nuremberg in which physicians would be authorised to oversee the work of apothecaries and only physicians would be permitted to undertake diagnosis. As a brief side note this is the physician Joachim Camerarius the younger, the son of the much more famous Joachim Camerarius the elder, classicist, colleague and biographer of Philipp Melanchthon.


Joachim Camerarius the younger Source: Wikimedia Commons

The programme set out by Camerarius in his Short and Ordered Considerations was not immediately accepted and put into practice by the Nuremberg city council but over the next few decades something similar was gradually put into place in Nuremburg; a process that involved a major political, cultural and social war between the physicians and the apothecaries. This gradual development is the subject of Murphy’s book. The rest of the introduction is devoted to a general road map of her work.

The book is divided into six chapters or perhaps, better said sections, each one of which deals with an aspect of the life and work of Early Modern physicians and how they relate to the changes in the role and status of the physicians that were taking place. These topics are initially handled for a given individual, and then developed for the city of Nuremberg in general with parallels being drawn for other cities and regions within the Holy Roman Empire. So what initially appears to be a very narrow and specialised study widens to cover a substantially area of Europe.

The opening chapter looks at a new, contemporary pharmacopeia, the Dispensatorium of Valerius Cordus, i.e. a catalogue of recipes for medical remedies. This area would become central in the dispute between the apothecaries and the physicians who could prescribe the remedies and which remedies should or could be prescribed.


The second chapter takes a detailed look at the position, role, and status of the city physician and how it differed from that of other sections of society in particular from that of the apothecaries. Moving on Murphy deals with the subject of anatomy, another area where the role of the physician would undergo a major change especially following the work of the century’s greatest anatomist, Andreas Vesalius. Turning away from the practical Murphy next addresses the role that books played in the life and work of the physician. We remain, for the next section, in the realm of the written word. In the absence of journals, which today play a major role in transmitting medical and related information, the early modern physicians had their correspondence. I personally am constantly amazed at just how many letters early modern scholars exchanged in their lifetimes with their colleagues throughout Europe. Thankfully, for the historian, some of these collections of correspondence have survived down the centuries and provide us with as valuable a source of information, as they once provided their authors and recipients. The final chapter returns to the starting point and a closer detailed look at Camerarius’ New Order of Medicine. Moving on Murphy now shows how the status and function of the physicians and apothecaries did change over time and the moves and disputes that accompanied those changes.


The book closes with a brief conclusion summarising what had been achieved by the Nuremberger physicians, I quote:

In their legal and civic battle with apothecaries, in their claim to profession primacy over surgeons and midwifes, in their bid to establish themselves as the arbiters of legitimate medicine, early modern physicians were decisively victorious.

They had succeeded in establishing a new order, one that basically still exists today. This leads to a, for historians, very interesting epilogue in which Murphy outlines how these not insignificant changes in the medical landscape of Europe became forgotten and at the same time mythologised down the succeeding centuries.

The book is pleasantly illustrated with the, in the mean time standard for academic publications, grey in grey prints. It has extensive endnotes, which largely consist of bibliographical references to the even more extensive bibliography of primary and secondary literature. The academic apparatus is rounded off by a good index.

Despite extensive historical research resulting in a highly detailed and dense text with intensive historical analysis, Murphy’s book is well written and a comparatively light read. Murphy has written an excellent book that delivers up a masterful demonstration of how a narrowly focused piece of historical research can be worked and presented so that it shines a light on a wide ranging historical development. The book should be of interest to anybody involved in the history of European medicine over the last five hundred years but will also make an interesting read for any early modern historian interested in going beyond the boundaries of their own discipline.

[1] Hannah Murphy, A New Order of Medicine: The Rise of Physicians in Reformation Nuremberg, University of Pittsburgh Press, Pittsburgh, 2019

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Filed under History of medicine, Renaissance Science

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

When contemplating the advent of the heliocentric hypothesis in the Early Modern Period, one of the first things that occurs to many people is the conflict between the emerging new astronomy and Christianity, in particular the Holy Roman Catholic Church. What took place in those early years was actually very different to what most people think occurred and to a large extent has over the years been blown up out of all proportions.

To a certain extent some sort of conflict was pre-programmed, as the Bible, which the majority in this period believed to be basically true , clearly presented a geocentric world, even to a small extent a flat earth given the Old Testament’s fundamentally Babylonian origins and the new astronomy was attempting to establish a heliocentric one. This situation called for a lot of diplomatic skill on the part of those proposing the new heliocentric cosmological system, a skill that some of those proponents, most notably Galileo Galilei failed to display.

Between the publication of Copernicus’ De revolutionibus, which was actively supported by several leading figures within the Catholic Church, and the sensational telescopic discoveries of 1610-1613 there was surprising little backlash against heliocentrism from any of the European Christian communities. I have dealt with this in detail in an earlier post and don’t intend to repeat myself here. The real problems first began in around 1615 and were provoked by Galileo Galilei and the Carmelite theologian Paolo Antonio Foscarini (c. 1565–1616).


Source: Wikimedia Commons

Again I have already dealt with this in great detail in two earlier posts, here and here, so I will only outline the real bone of contention now, which surprisingly has little to do with the science and a lot to do with who gets to interpret the Holy Word of God e.g. The Bible.

From its foundation the Catholic Church had claimed the exclusive right to interpret the Bible for its followers, i.e. all true Christians. With time that interpretation was anchored in the writings of the early church fathers, what they had written was holy gospel and to openly contradict it was considered to be heresy. The Church was not only a powerful religious institution but also a powerful political one and over the centuries the adage that power corrupts and absolute power corrupts absolutely certainly proved true within the Catholic Church. This led to several attempts to reform the Church and bring it back to the ‘true path’ as outlined in the gospels.

Before what we now know as The Reformation, notable attempts on varying levels were made by, amongst other, John Wycliffe (c. 1320s–1384) in England, Jan Hus (c. 1372–1415) in Bohemia and Desiderus Erasmus (1466–1536), although Erasmus’ reform efforts were very moderate when compared to the other two and those that came after. In the sixteenth century that which we call the Protestant Reformation broke out in several parts of Europe instigated by Martin Luther (1483–1546), Philipp Melanchthon (1497–1560), Thomas Müntzer (1489–1525), Huldrych Zwingli (1484–1531), Jean Calvin (1509–1564) and a host of other minor figure, such as Andreas Osiander (1496 or 1498–1552), who wrote the infamous Ad lectorum in De revolutionibus. The major characteristic of the Reformation was that those calling for reform demanded the right for each individual to be allowed to interpret The Bible for themselves, thus removing the Church’s monopoly on biblical interpretations. This was of course unacceptable for the Catholic Church, which in turn launched its Counter Reformation, with the Council of Trent (1545–1563), to try and stem the tide of dissent. This was the situation in 1615 just three years before the outbreak of the Thirty Years War, one of the bloodiest conflicts in the history of Europe triggered by just this religious dispute, when Galileo made the move that turned the Catholic Church against heliocentrism and began Galileo’s own downfall.

Before we examen what Galileo actually did to so annoy the Catholic Church, it pays to look at the historical context in which this all took place. Too often people try to judge what happened from a presentist point of view, thereby distorting the historical facts. As usual when I write on this subject I am not trying to apologise for the Catholic Church’s actions or to excuse them, merely to present them within the practices and beliefs at the beginning of the seventeenth century. Firstly, this was a historical period in which all social, cultural and political institutions were hierarchical and fairly rigidly structured. It was an age of absolutism in which most rulers, including or above all the Pope, had and exercised absolute power. Secondly, there was no such thing as freedom of speech or freedom of thought in either religious or secular society. Those at the top largely prescribed what could or could not be said or thought out loud. Anybody who pushed against those prescriptions could expect to be punished for having done so.


Galileo Portrait by Ottavio Leoni Source: Wikimedia Commons

In 1615 both Foscarini and Galileo tried to tell the Church how to reinterpret those passages in the Bible that presupposed a geocentric cosmos in order to make a heliocentric cosmos theologically acceptable. This was simply not on. In my comments I will restrict myself to the case of Galileo. Modern commentators think that what Galileo said in his Letter to Castelli and in the extended version, his Letter to Christina, is eminently sensible and applaud him for his theological analysis but in doing so they miss several important points. In the Renaissance intellectual hierarchy theologians were at the top and mathematici, and Galileo was a mere mathematicus, were very much at the bottom. In fact the social status of the mathematicus was so low that Galileo telling the theologians how to do their job was roughly equivalent to the weekly cleaning lady telling the owner of a luxury villa how to run his household. This was definitely a massive failure on Galileo’s part, one that he should have been well aware of. The very low social and intellectual status of mathematici was the reason why he insisted on being appointed court philosophicus and not just mathematicus to the Medicean court. Philosophers ranked just below theologians in the hierarchy. Also given the fact that the Reformation/Counter Reformation conflict was rapidly approaching its high point in the Thirty Years War, this was not the time to tell the Catholic Church how to interpret the Bible.

As formal complaints began to be made about his Letter to Castelli, Galileo realised that he had gone too far and claimed that the copies in circulation had been changed by his enemies to make him look bad and presented the Church with a modified version to show what “he had actually written.” I fact we now know that the unmodified version was his original letter.

The writings of Foscarini and Galileo on the subject now led the Church to formally examine the relationship between Catholic doctrine and the heliocentric hypothesis, for the first time, and the result was not good for Galileo and the heliocentric hypothesis. A commission of eleven theologians, known as Qualifiers, undertook this examination and came to the conclusion that the idea that the Sun is stationary is “foolish and absurd in philosophy, and formally heretical since it explicitly contradicts in many places the sense of Holy Scripture…”; while the Earth’s movement “receives the same judgement in philosophy and … in regard to theological truth it is at least erroneous in faith.” The first part is obvious the Bible states clearly that it is the Sun that moves and not the Earth and as the heliocentric hypothesis directly contradicts Holy Scripture it is formally heretical. The second part is more interesting because it that the hypothesis is philosophically, read scientifically, absurd and foolish. Although the language used here in the judgement is rather extreme it was a fact in 1615 that there existed no empirical proof for the heliocentric hypothesis, actually most of the then available empirical evidence supported a geocentric cosmos. If there had been empirical support for heliocentrism then the Church’s judgement might well have been different, as Roberto Bellarmino (1542–1621) wrote in his infamous letter to Foscarini:

Third, I say that, if there were a real proof that the Sun is in the centre of the universe, that the Earth is in the third sphere, and that the Sun does not go round the Earth but the Earth round the Sun, then we should have to proceed with great circumspection in explaining passages of Scripture which appear to teach the contrary, and we should rather have to say that we did not understand them than declare an opinion to be false which is proved to be true.


Roberto Bellarmino Source: Wikimedia Commons

In other words, if you provide proof of your hypothesis, then we will be prepared to reinterpret the Bible.

This was the point where Galileo, realising that he was potentially in serious trouble, first rushed to Rome to peddle his theory of the tides, which he appeared to believe delivered the necessary empirical proof for the heliocentric hypothesis.


Source: Wikimedia Commons

This theory had been developed together with Paolo Sarpi (1552–1623) in the 1590’s and basically claimed that the tides were caused by the movements of the Earth, in the same way that water sloshes around in a moving bowl. The theory has however a fatal empirical flaw; it only allows for one high tide in twenty-four hours whereas there are actually two. Galileo tried to deal with this discrepancy with a lot of hand waving but couldn’t really provide a suitable explanation. This was, however, irrelevant in 1615, as Galileo having through his actions poked the proverbial bear with a sharp stick, nobody was prepared to listen to his latest offerings and his efforts fell on deaf ears.

The inevitable happened, the Church formally banned heliocentricity in 1616, although it was never actually declared heretical, something that only the Pope could do and no Pope ever did, and books explicating the heliocentric hypothesis were placed on the Index of forbidden books. Interestingly Copernicus’ De revolutionibus was only placed on the Index until corrected and rather surprisingly this was carried out fairly quickly, the corrected version becoming available to Catholic scholars already by 1621. The Church had realised that this was an important book that should not be banned completely. The corrections consisted or removing or correcting the surprisingly few places in the text where the heliocentric hypothesis was stated as being scientifically true. This meant that Catholics were permitted to write about and discuss heliocentricity as a hypothesis but not to claim that it was empirically true.

Galileo who together with Foscarini had provoked this whole mess got off relatively lightly. At the Pope’s request he was personally informed by Cardinal Roberto Bellarmino that he could no longer hold or teach the heliocentric theory and given a document confirming this in writing. He was not punished in anyway and continued to be popular amongst leading figures in the Church including Maffeo Barberini, the future Pope Urban VIII.

Many modern commentators say why couldn’t the Church accept the eminently sensible suggestion made by Galileo and Foscarini and thus avoid the whole sorry mess. The answer is quite simple. If they had done so they would have surrendered their absolute right to interpret Holy Scripture, which, as pointed out above, lay at the centre of the Reformation/Counter Reformation conflict; a right that the Catholic Church has not surrendered up to the present day.





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

Finding your way on the Seven Seas in the Early Modern Period

I spend a lot of my time trying to unravel and understand the complex bundle that is Renaissance or Early Modern mathematics and the people who practiced it. Regular readers of this blog should by now be well aware that the Renaissance mathematici, or mathematical practitioners as they are generally known in English, did not work on mathematics as we would understand it today but on practical mathematics that we might be inclined, somewhat mistakenly, to label applied mathematics. One group of disciplines that we often find treated together by one and the same practitioner consists of astronomy, cartography, navigation and the design and construction of tables and instruments to aid the study of these. This being the case I was delighted to receive a review copy of Margaret E. Schotte’s Sailing School: Navigating Science and Skill, 1550–1800[1], which deals with exactly this group of practical mathematical skills as applied to the real world of deep-sea sailing.

Sailing School001.jpg

Schotte’s book takes the reader on a journey both through time and around the major sea going nations of Europe, explaining, as she goes, how each of these nations dealt with the problem of educating, or maybe that should rather be training, seamen to become navigators for their navel and merchant fleets, as the Europeans began to span the world in their sailing ships both for exploration and trade.

Having set the course for the reader in a detailed introduction, Schotte sets sail from the Iberian peninsular in the sixteenth century. It was from there that the first Europeans set out on deep-sea voyages and it was here that it was first realised that navigators for such voyages could and probably should be trained. Next we travel up the coast of the Atlantic to Holland in the seventeenth century, where the Dutch set out to conquer the oceans and establish themselves as the world’s leading maritime nation with a wide range of training possibilities for deep-sea navigators, extending the foundations laid by the Spanish and Portuguese. Towards the end of the century we seek harbour in France to see how the French are training their navigators. Next port of call is England, a land that would famously go on, in their own estimation, to rule the seven seas. In the eighteenth century we cross the Channel back to Holland and the advances made over the last hundred years. The final chapter takes us to the end of the eighteenth century and the extraordinary story of the English seaman Lieutenant Riou, whose ship the HMS Guardian hit an iceberg in the Southern Atlantic. Lacking enough boats to evacuate all of his crew and passengers, Riou made temporary repairs to his vessel and motivating his men to continuously pump out the waters leaking into the rump of his ship, he then by a process of masterful navigation, on a level with his contemporaries Cook and Bligh, brought the badly damaged frigate to safety in South Africa.

Sailing School004

In each of our ports of call Schotte outlines and explains the training conceived by the authorities for training navigators and examines how it was or was not put into practice. Methods of determining latitude and longitude, sailing speeds and distances covered are described and explained. The differences in approach to this training developed in each of the sea going European nations are carefully presented and contrasted. Of special interest is the breach in understanding of what is necessary for a trainee navigator between the mathematical practitioners, who were appointed to teach those trainees, and the seamen, who were being trained, a large yawning gap between theory and practice. When discussing the Dutch approach to training Schotte clearly describes why experienced coastal navigators do not, without retraining, make good deep-sea navigators. The methodologies of these two areas of the art of navigation are substantially different.

The reader gets introduced to the methodologies used by deep-sea navigators, the mathematics developed, the tables considered necessary and the instruments and charts that were put to use. Of particular interest are the rules of thumb utilised to make course corrections before accurate methods of determining longitude were developed. There are also detailed discussions about how one or other aspect of the art of navigation was emphasised in the training in one country but considered less important in another. One conclusion the Schotte draws is that there is not really a discernable gradient of progress in the methods taught and the methods of teaching them over the two hundred and fifty years covered by the book.

Sailing School003.jpg

As well as everything you wanted to know about navigating sailing ships but were too afraid to ask, Schotte also delivers interesting knowledge of other areas. Theories of education come to the fore but an aspect that I found particularly fascinating were her comments on the book trade. Throughout the period covered, the teachers of navigation wrote and marketed books on the art of navigation. These books were fairly diverse and written for differing readers. Some were conceived as textbooks for the apprentice navigators whilst others were obviously written for interested, educated laymen, who would never navigate a ship. Later, as written exams began to play a greater role in the education of the aspirant navigators, authors and publishers began to market books of specimen exam questions as preparation for the exams. These books also went through an interesting evolution. Schotte deals with this topic in quite a lot of detail discussing the authors, publishers and booksellers, who were engaged in this market of navigational literature. This is detailed enough to be of interest to book historians, who might not really be interested in the history of navigation per se.

Schotte is excellent writer and the book is truly a pleasure to read. On a physical level the book is beautifully presented with lots of fascinating and highly informative illustrations. The apparatus starts with a very useful glossary of technical terms. There is a very extensive bibliography and an equally extensive and useful index. My only complaint concerns the notes, which are endnotes and not footnotes. These are in fact very extensive and highly informative containing lots of additional information not contained in the main text. I found myself continually leafing back and forth between main text and endnotes, making continuous reading almost impossible. In the end I developed a method of reading so many pages of main text followed by reading the endnotes for that section of the main text, mentally noting the number of particular endnotes that I wished to especially consult. Not ideal by any means.

This book is an essential read for anybody directly or indirectly interested in the history of navigation and also the history of practical mathematics. If however you are generally interested in good, well researched, well written history then you will almost certainly get a great deal of pleasure from reading this book.

[1] Margaret E. Schotte, Sailing School: Navigating Science and Skill, 1550–1800, Johns Hopkins University Press, Baltimore, 2019.


Filed under Book Reviews, History of Astronomy, History of Cartography, History of Mathematics, History of Navigation, Renaissance Science, Uncategorized

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

The first period of telescopic, astronomical discoveries came to an end in 1613, which was seventy years after the publication of Copernicus’ De revolutionibus. This makes it a good point to stop and take stock of the developments that had taken place since the appearance of that epoch defining magnum opus. First we need to remind ourselves of the situation that had existed before Copernicus heliocentric hypothesis entered the world and triggered a whole new cosmology and astronomy debate. The mainstream standpoint was an uneasy combination of Aristotelian cosmology and Ptolemaic astronomy. Uneasy because, as some saw it, the Ptolemaic deferent and epicycle model of planetary motion contradicted Aristotle’s homocentric principle, which led to a revival of homocentric astronomy. Others saw the principle of uniform circular motion contradicted by Ptolemaeus’ use of the equant point. In fact, we know that the removal of the equant point, for exactly this reason, was the starting point of Copernicus’ own reform efforts. Another minority view that was extensively discussed was a geocentric system with diurnal rotation, as originated in antiquity by Heraclides of Pontus, regarded by some as more rational or acceptable than that the sphere of the fixed stars rotated once in twenty-four hours. Also still up for debate was the Capellan system with Mercury and Venus orbiting the Sun in a geocentric system. Then came Copernicus and added a new radical alternative to the debate.

By 1613 most of the Aristotelian cosmology had been disposed of bit for bit. Aristotle’s sublunar meteorological comets had definitely become supralunar astronomical objects, although what exactly they were was still largely a mystery. As we shall see Galileo later embarrassed himself by maintaining a position on comets very close to that of Aristotle. The comets becoming supralunar had also disposed of Aristotle’s crystalline spheres, although Copernicus seems to have still believed in them. The telescopic discovery of the geographical features on the Moon and the spots on the Sun had put an end to Aristotle’s perfection of the celestial spheres. They together with the comets and the supernovas of 1573 and 1604, both of which had clearly been shown to be supralunar, also contradicted his immutability of the heavens. The discovery of the four largest moons of Jupiter ended the homocentric concept and the discovery of the phases of Venus, originating in a solar orbit, ruled a pure geocentric system but not a geo-heliocentric one. As a result of all these changes cosmology was up for grabs.

In astronomy the biggest single change was that nearly all astronomers, following Copernicus, now believed in the reality of their models and no longer viewed them as purely mathematical constructions designed to save the phenomena. This was a major shift as previously the discussion of the reality of the heavens was regarded as a discussion for philosophers and definitely not astronomers. So which models were up for discussion? Had in the intervening seventy years the debate simplified, reduced to a choice between two competing models, Ptolemaic geocentrism and Copernican heliocentrism, as Galileo would have us believe twenty years later? Actually no, if anything the situation had got considerably more confused with a whole raft full of astronomical models jostling for a place at the table. What were these competing models?

Given the telescopic observations of the phases of Venus and the assumption of similar phases for Mercury, a pure Ptolemaic geocentric model should have been abandoned but there was still a hard core that refused to simply give up this ancient model. Christoph Clavius (1538–1612) in the last edition of his Sphaera, the standard Jesuit textbook on astronomy, acknowledged problems with the geocentric model but urged his readers to find solutions to the problems within the model. As late as 1651 Giovanni Battista Riccioli (1598–1671), in the famous frontispiece to his Almagestum novum, shows Ptolemaeus lying defeated on the ground, whilst the heliocentric and geo-heliocentric systems are weighed against each other, but he is saying, I will rise again.


Frontispiece of Riccioli’s 1651 New Almagest. Source: Wikimedia Commons

Due to William Gilbert’s revival of the Heraclidian diurnal rotation, we now have two geocentric models, with and without diurnal rotation. The Copernican heliocentric system is, of course, still very much in the running but with much less support than one might expect after all the developments of the intervening seventy years.

Despite the phases of Venus all the various geo-heliocentric models are still in contention and because of the lack of empirical evidence for movement of the Earth these are actually more popular at this point in time than heliocentric ones. However, despite the lack of empirical evidence diurnal rotation enjoys a surprising level of popularity. We have a Capellan system, Venus and Mercury orbit the Sun, which orbits the Earth, both with and without diurnal rotation. Very much in consideration is the full Tychonic system; the five planets orbit the Sun, which together with the Moon orbits the Earth. Once again both with and without diurnal rotation. Riccioli favoured another variation with Venus, Mercury and Mars orbiting the Sun but with Jupiter and Saturn orbiting the Earth along with the Sun and Moon.

Perhaps the most interesting development was Kepler’s heliocentric system. Whilst Kepler regarded his system as Copernican, others regarded his elliptical system as a rival to not only to the geocentric and geo-heliocentric system but also to the Copernican heliocentric system with its deferent and epicycle orbital models. The most prominent example of this being Galileo, who promoted the Copernican system, whilst deliberately ignoring Kepler’s more advanced developments.

We can find solid evidence for this multiplicity of systems in various sources. The earliest in a card game devised by Johann Praetorius (1573–1616), professor for astronomy at the University of Altdorf near Nürnberg, which only exists in manuscript.


Source: Wikimedia Commons











Source: All playing card images Wikimedia Commons

Another much read source is the extraordinary Anatomy of Melancholy by the Oxford scholar Robert Burton (1577–1640). First published in 1621, it was republished five times over the next seventeen years, each edition being massively modified and expanded.


The Anatomy of Melancholy frontispiece 1638 ed. Source: Wikimedia Commons

In a section entitled Melancholy of the Air Burton discusses the various astronomical models, favouring the system of David Origanus (1558–1629), professor for Geek Greek and mathematics at the University of Frankfurt an der Oder, a Tychonic system with diurnal rotation.


Source: Wikimedia Commons

Burton, as well as being one of the most erudite scholars of the seventeenth century, was also a practicing astrologer, who is said to have hung himself in his Oxford chambers to fulfil his own prediction of his death.

Already mentioned above is Giovanni Battista Riccioli, whose Almagestum novum (1551) contains descriptions of a wide range of different systems.


Riccioli as portrayed in the 1742 Atlas Coelestis (plate 3) of Johann Gabriel Doppelmayer. Source: Wikimedia Commons

The book also contains a list of 126 arguments pro and contra heliocentricity, 49 for and 77 against, in which religios arguments play only a very minor role.

Another Jesuit was Athanasius Kircher (1602–1680), who sat at the centre of a world spanning astronomy correspondence network, receiving astronomical data from Jesuits all of the world, collating it and re-distributing it to astronomers throughout Europe.


Source: Wikimedia Commons

He described six different systems as late as 1656 in his Itinerarium extaticum, with a revised edition from 1671.


Diagrams of the different world systems, Ptolemaic, Platonic, Egyptian, Copernican, Tychonic and semi-Tychonic from Iter Exstaticum (1671 ed.) p. 37 Source:

Contrary to a widespread view the question of the correct astronomical system was still very much an open question throughout most of the seventeenth century, largely because there existed no conclusive empirical evidence available to settle the question.





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

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

The publication of Galileo’s Sidereus Nuncius was by no means the end of the spectacular and game changing telescopic astronomical discoveries during that first hot phase, which spanned 1610 to 1613. There were to be three further major discoveries, one of which led to a bitter priority dispute that would in the end play a role in Galileo’s downfall and another of which would sink Ptolemaeus’ geocentric model of the cosmos for ever.

The first new discovery post Sidereus Nuncius was the rather strange fact that Saturn appeared to have ears or as Galileo put it, it was three bodies “accompanied by two attendants who never leave his side.”


Galileo’s drawings of Saturn

What Galileo had in fact observed were the rings of Saturn, which however because of the relative positions of Saturn and the Earth were not discernable as rings but as strange semi-circular projections on either side of the planet. What exactly the strange protrusions visible on Saturn were would remain a mystery until Christiaan Huygens solved the problem much later in the century. The astronomers of the Collegio Romano claimed priority on the Saturn discovery. Whether they or Galileo saw the phenomenon first cannot really be determined but it demonstrates once again that Galileo was by no means the only one making these new telescopic discoveries. Saturn’s two “attendants” didn’t really play a role in the ongoing astronomy/cosmology debate but the next discovery did in a very major way.

Probably stimulated by a letter from his one time student Benedetto Castelli (1578–1643) Galileo turned his attention to Venus and its potential phases.


Benedetto Castelli Source: Wikimedia Commons

If Venus was indeed lit by the sun then in both Ptolemaeus’ geocentric system and in a heliocentric system it would, like the moon, display phases but these phases would differ according to whether Venus orbited the Earth in a geocentric system or the sun in either a heliocentric or a geo-heliocentric one. Galileo’s observations clearly showed that the phases of Venus were consistent with a solar orbit and not a terrestrial one.


The Phases of Venus in both systems

The pure Ptolemaic geocentric system was irredeemably sunk but not, and that must be strongly emphasised, a number of geo-heliocentric systems. As already mentioned earlier, because they never strayed far from the sun’s vicinity and in a geocentric system even shared the sun orbital period, Mercury and Venus had since antiquity been assumed, by some, to orbit the sun whereas the sun orbited the earth in what is known as the Capellan system; a system that was very popular in the Middle Ages and had been praised as such by Copernicus in his De revolutionibus. Phases of Venus indicating a solar orbit were, of course, also consistent with a full Tychonic system in which the planets, apart from the moon, orbited the sun, which in turn together with the moon orbited the earth, as well as several variant semi-Tychonic systems. It was assumed that Mercury also orbited the sun, although its phases were first observed by  Pierre Gassendi (1592–1655) in 1631. The heliocentric phases of Venus were also discovered independently by Thomas Harriot, who, as always, didn’t publish, by Simon Marius, whose discovery was published by Kepler, and by the Collegio Romano astronomers, who also didn’t published but announced their discovery in their correspondence.

The other major telescopic discovery was the presence of blemishes or spots on the surfaces of the sun, again something that contradicted Aristotle’s assumption of the perfection of the celestial bodies. This discovery led to one of Galileo’s biggest priority disputes. This whole sorry episode began with a communication from the Augsburger banker and science fan, Marcus Welser(1558–1614), who was also a close friend of the Jesuits.


Marcus Welser Source: Wikimedia Commons

This communication contained three letters on sunspots written by the Ingolstädter Jesuit Christoph Scheiner (1573 or 75–1650) under the pseudonym, Appeles.


Christoph Scheiner (artist unknown)

Welser wanted to hear Galileo’s opinion on Scheiner’s discovery. Galileo was deeply offended, the heavens were his territory and only he was allowed to make discoveries there! The dispute was carried on two levels, the first was the question of priority and the second was the question of how to interpret what had been observed. Although, during the whole dispute Galileo kept changing the date when he first observed sunspots, in order to establish his priority and to claim the discovery as his, viewed with hindsight the priority dispute was a bit of a joke. We now know that Thomas Harriot  had recorded observations of sunspot before either Galileo or Scheiner but because he never published his observations, they were blissfully unaware of his priority. Even stranger, Johannes Fabricius (1587–1616), the son of Kepler’s intellectual sparing partner David Fabricius, had brought home a telescope from university in Leiden, where Rudolph Snell (1546–1613) was already holding lectures on the telescope in 1610, and together with his father had not only been observing sunspots but had already published a pamphlet on his observation in Wittenberg in 1611, where he was now studying.


The second part of the dispute was by far and away the more important. Scheiner had initially interpreted the sunspots as shadows cast upon the surface of the sun by small satellites orbiting it. It is was possible that through this interpretation he wished to preserve the Aristotelian perfection of this celestial body. Galileo opposed this interpretation and was convinced, correctly as it turned out, that the sunspots were actually some sort of blemishes on the surface of the sun.

Galileo answered Scheiner’s letters with three of his own, in the process stepping up his observation of the sunspots, as well as gathering observational reports from other astronomers. He was able to show through the quality of his observations and through mathematical analysis that the sunspots must be on the surface of the sun and that the sun must be revolving about its axis. With time Scheiner came to accept Galileo’s conclusions. Scheiner published three more sunspot letters under the title Accuratior Disquisitio in 1612.


The Accademia dei Lincei, which had elected Galileo a member when he came to Rome to celebrate the Jesuit’s confirmation of his telescopic discoveries, published Scheiner’s original three letters together with Galileo’s three answering letters in a book titled, Istoria e Dimontrazioni, in 1613.


Having in his opinion won the priority dispute and proved that the sunspots were on the surface of the sun, Galileo basically gave up on his solar observations; Scheiner did not. Having built what was effectively the first Keplerian or astronomical telescope with two convex lenses, instead of one convex and one concave, as in the Dutch or Galilean telescope, giving a much wider field of vision and a much clearer and stronger image, Scheiner set out on a programme of solar astronomy.


Scheiner Observing the Sun

The astronomical telescope provided an inverted image but this was irrelevant as Scheiner was projecting the image onto paper in order to simplify the drawing on the sunspots and also to protect his eyes. A method also used by Fabricius and Galileo. He mounted his telescope on a special holder that allowed him to follow the sun in its journey across the heavens.


Scheiner’s Helioscope

The end of this programme was his Rosa Ursina sive Sol, published in 1626-30, which remained the most important book on solar astronomy until the nineteenth century.


Scheiner’s Sunspot Observations

Galileo’s and Scheiner’s priority dispute entails a strong sense of historical irony. Not only did Harriot begin observing sunspots earlier than both of them and Johannes Fabricius publish on the subject before either of them but Chinese and Korean astronomers had been recording naked-eye observations of sunspots since the first millennium BCE. There are also scattered observations of sunspots beginning with the ancient Greeks and down through the Middle Ages in Europe.


A drawing of a sunspot in the Chronicles of John of Worcester 1129 Source: Wikimedia Commons

Famously Kepler recorded observations of a large sunspot that he made in 1607 mistakenly believing that he was observing a transit of Mercury.

1613 marks the end of the first phase of astronomical telescopic discoveries, partially because the observers continued to use Dutch or Galilean telescopes instead of changing to the vastly superior Keplerian or astronomical telescopes, largely influenced by Galileo’s authority, he publicly rubbished astronomical telescopes, basically because he hadn’t started using them first; the transition to the better instruments would take a couple of decades to be completed.









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

Why, FFS! why?

On Twitter this morning physicist and science writer Graham Farmelo inadvertently drew my attention to a reader’s letter in The Guardian from Sunday by a Collin Moffat. Upon reading this load of old cobblers, your friendly, mild mannered historian of Renaissance mathematics instantly turned into the howling-with-rage HISTSCI_HULK. What could possibly have provoked this outbreak? I present for your delectation the offending object.

I fear Thomas Eaton (Weekend Quiz, 12 October) is giving further credence to “fake news” from 1507, when a German cartographer was seeking the derivation of “America” and hit upon the name of Amerigo Vespucci, an obscure Florentine navigator. Derived from this single source, this made-up derivation has been copied ever after.

The fact is that Christopher Columbus visited Iceland in 1477-78, and learned of a western landmass named “Markland”. Seeking funds from King Ferdinand of Spain, he told the king that the western continent really did exist, it even had a name – and Columbus adapted “Markland” into the Spanish way of speaking, which requires an initial vowel “A-”, and dropped “-land” substituting “-ia”.

Thus “A-mark-ia”, ie “America”. In Icelandic, “Markland” may be translated as “the Outback” – perhaps a fair description.

See Graeme Davis, Vikings in America (Birlinn, 2009).

Astute readers will remember that we have been here before, with those that erroneously claim that America was named after a Welsh merchant by the name of Richard Ap Meric. The claim presented here is equally erroneous; let us examine it in detail.

…when a German cartographer was seeking the derivation of “America” and hit upon the name of Amerigo Vespucci, an obscure Florentine navigator.

It was actually two German cartographers Martin Waldseemüller and Matthias Ringmann and they were not looking for a derivation of America, they coined the name. What is more, they give a clear explanation as to why and how the coined the name and why exactly they chose to name the newly discovered continent after Amerigo Vespucci, who, by the way, wasn’t that obscure. You can read the details in my earlier post. It is of interest that the supporters of the Ap Meric theory use exactly the same tactic of lying about Waldseemüller and Ringmann and their coinage.

The fact is that Christopher Columbus visited Iceland in 1477-78, and learned of a western landmass named “Markland”.

Let us examine what is known about Columbus’ supposed visit to Iceland. You will note that I use the term supposed, as facts about this voyage are more than rather thin. In his biography of Columbus, Felipe Fernandez-Armesto, historian of Early Modern exploration, writes:

He claimed that February 1477–the date can be treated as unreliable in such a long –deferred recollection [from 1495]–he sailed ‘a hundred leagues beyond’ Iceland, on a trip from Bristol…

In “Christopher Columbus and the Age of Exploration: An Encyclopedia”[1] edited by the American historian, Silvio A. Bedini, we can read:

The possibility of Columbus having visited Iceland is based on a passage in his son Fernando Colón’s biography of his father. He cites a letter from Columbus stating that in February 1477 he sailed “a hundred leagues beyond the island of Til” (i.e. Thule, Iceland). But there is no evidence to his having stopped in Iceland or spoken with anyone, and in any case it is unlikely that anyone he spoke to would have known about the the Icelandic discovery of Vinland.

This makes rather a mockery of the letter’s final claim:

Seeking funds from King Ferdinand of Spain, he told the king that the western continent really did exist, it even had a name – and Columbus adapted “Markland” into the Spanish way of speaking, which requires an initial vowel “A-”, and dropped “-land” substituting “-ia”.

Given that it is a well established fact that Columbus was trying to sail westward to Asia and ran into America purely by accident, convinced by the way that he had actually reached Asia, the above is nothing more than a fairly tale with no historical substance whatsoever.

To close I want to address the question posed in the title to this brief post. Given that we have a clear and one hundred per cent reliable source for the name of America and the two men who coined it, why oh why do people keep coming up with totally unsubstantiated origins of the name based on ahistorical fantasies? And no I can’t be bothered to waste either my time or my money on Graeme Davis’ book, which is currently deleted and only available as a Kindle.

[1] On days like this it pays to have one book or another sitting around on your bookshelves.

Felipe Fernández-Armesto, Columbus, Duckworth, London, ppb 1996, p. 18. Christopher Columbus and the Age of Exploration: An Encyclopedia, ed. Silvio A. Bedini, Da Capo Press, New York, ppb 1992, p. 314


Filed under History of Cartography, History of Navigation, Myths of Science, Renaissance Science

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

A widespread myth in the popular history of astronomy is that Galileo Galilei (1564–1642) was the first or even the only astronomer to realise the potential of the newly invented telescope as an instrument for astronomy. This perception is very far from the truth. He was just one of a group of investigator, who realised the telescopes potential and all of the discoveries traditionally attributed to Galileo were actually made contemporaneously by several people, who full of curiosity pointed their primitive new instruments at the night skies. So why does Galileo usually get all of the credit? Quite simply, he was the first to publish.


Galileo’s “cannocchiali” telescopes at the Museo Galileo, Florence

Starting in the middle of 1609 various astronomers began pointing primitive Dutch telescopes at the night skies, Thomas Harriot (1560–1621) and his friend and student William Lower (1570–1615) in Britain, Simon Marius (1573–1625) in Ansbach, Johannes Fabricius (1587–1616) in Frisia, Odo van Maelcote (1572–1615) and Giovanni Paolo Lembo (1570–1618) in Rome, Christoph Scheiner (1573 or 1575–1650) in Ingolstadt and of course Galileo in Padua. As far as we can ascertain Thomas Harriot was the first and the order in which the others took up the chase is almost impossible to determine and also irrelevant, as it was who was first to publish that really matters and that was, as already stated, Galileo.

Harriot made a simple two-dimensional telescopic sketch of the moon in the middle of 1609.


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

Both Galileo and Simon Marius started making telescopic astronomical observations sometime late in the same year. At the beginning Galileo wrote his observation logbook in his Tuscan dialect and then on 7 January 1610 he made the discovery that would make him famous, his first observation of three of the four so-called Galilean moons of Jupiter.


It was on this page that Galileo first noted an observation of the moons of Jupiter. This observation upset the notion that all celestial bodies must revolve around the Earth. Source: Wikimedia Commons

Galileo realised at once that he had hit the jackpot and immediately changed to writing his observations in Latin in preparation for a publication. Simon Marius, who made the same discovery just one day later, didn’t make any preparations for immediate publication. Galileo kept on making his observations and collecting material for his publication and then on 12 March 1610, just two months after he first saw the Jupiter moons, his Sidereus Nuncius (Starry Messenger of Starry Message, the original Latin is ambiguous) was published in Padua but dedicated to Cosimo II de Medici, Fourth Grand Duke of Tuscany. Galileo had already negotiated with the court in Florence about the naming of the moons; he named them the Medicean Stars thus taking his first step in turning his discovery into personal advancement.


Title page of Sidereus nuncius, 1610, by Galileo Galilei (1564-1642). *IC6.G1333.610s, Houghton Library, Harvard University Source: Wikimedia Commons

What exactly did Galileo discover with his telescope, who else made the same discoveries and what effect did they have on the ongoing astronomical/cosmological debate? We can start by stating quite categorically that the initial discoveries that Galileo published in his Sidereus Nuncius neither proved the heliocentric hypothesis nor did they refute the geocentric one,

The first discovery that the Sidereus Nuncius contains is that viewed through the telescope many more stars are visible than to the naked-eye. This was already known to those, who took part in Lipperhey’s first ever public demonstration of the telescope in Den Haag in September 1608 and to all, who subsequently pointed a telescope of any sort at the night sky. This played absolutely no role in the astronomical/cosmological debate but was worrying for the theologians. Christianity in general had accepted both astronomy and astrology, as long as the latter was not interpreted deterministically, because the Bible says  “And God said, Let there be lights in the firmament of the heaven to divide the day from night; and let them be for signs, and for seasons, and for days, and years:” (Gen 1:14). If the lights in the heavens are signs from God to be interpreted by humanity, what use are signs that can only be seen with a telescope?

Next up we have the fact that some of the nebulae, indistinct clouds of light in the heavens, when viewed with a telescope resolved into dense groups of stars. Nebulae had never played a major role in Western astronomy, so this discovery whilst interesting did not play a major role in the contemporary debate. Simon Marius made the first telescopic observations of the Andromeda nebula, which was unknown to Ptolemaeus, but which had already been described by the Persian astronomer, Abd al-Rahman al-Sufi (903–986), usually referred to simply as Al Sufi. It is historically interesting because the Andromeda nebula was the first galaxy to be recognised outside of the Milky Way.


Al Sufi’s drawing of the constellation Fish with the Andromeda nebula in fount of it mouth

Galileo’s next discovery was that the moon was not smooth and perfect, as required of all celestial bodies by Aristotelian cosmology, but had geological feature, mountains and valleys, just like the earth i.e. the surface was three-dimensional and not two-dimensional, as Harriot had sketched it. This perception of Galileo’s is attributed to the fact that he was a trained painter used to creating light and shadows in paintings and he thus recognised that what he was seeing on the moons surface was indeed shadows cast by mountains.

As soon as he read the Sidereus Nuncius, Harriot recognised that Galileo was correct and he went on to produce the first real telescopic map of the moon.


Thomas Harriot’s 1611 telescopic map of the moon Source: Wikimedia Commons

Galileo’s own washes of the moon, the most famous illustrations in the Sidereus Nuncius, are in fact studies to illustrate his arguments and not accurate illustrations of what he saw.


Galileo’s sketches of the Moon from Sidereus Nuncius. Source: Wikimedia Commons

That the moon was earth like and for some that the well-known markings on the moon, the man in the moon etc., are in fact a mountainous landscape was a view held by various in antiquity, such as Thales, Orpheus, Anaxagoras, Democritus, Pythagoras, Philolaus, Plutarch and Lucian. In particular Plutarch (c. 46–c. 120 CE) in his On the Face of the Moon in his Moralia, having dismissed other theories including Aristotle’s wrote:

Just as our earth contains gulfs that are deep and extensive, one here pouring in towards us through the Pillars of Herakles and outside the Caspian and the Red Sea with its gulfs, so those features are depths and hollows of the Moon. The largest of them is called “Hecate’s Recess,” where the souls suffer and extract penalties for whatever they have endured or committed after having already become spirits; and the two long ones are called “the Gates,” for through them pass the souls now to the side of the Moon that faces heaven and now back to the side that faces Earth. The side of the Moon towards heaven is named “Elysian plain,” the hither side, “House of counter-terrestrial Persephone.”

So Galileo’s discovery was not so sensational, as it is often presented. However, the earth-like, and not smooth and perfect, appearance of the moon was yet another hole torn in the fabric of Aristotelian cosmology.

Of course the major sensation in the Sidereus Nuncius was the discovery of the four largest moons of Jupiter.


Galileo’s drawings of Jupiter and its Medicean Stars from Sidereus Nuncius. Image courtesy of the History of Science Collections, University of Oklahoma Libraries. Source: Wikimedia Commons

This contradicted the major premise of Aristotelian cosmology that all of the celestial bodies revolved around a common centre, his homo-centricity.  It also added a small modicum of support to a heliocentric cosmology, which had suffered from the criticism, if all the celestial bodies revolve around the sun, why does the moon continue to revolve around the earth. Now Jupiter had not just one but four moons, or satellites as Johannes Kepler called them, so the earth was no longer alone in having a moon. As already stated above Simon Marius discovered the moons of Jupiter just one day later than Galileo but he didn’t publish his discovery until 1614. A delay that would later bring him a charge of plagiarism from Galileo and ruin his reputation, which was first restored at the end of the nineteenth century when an investigation of the respective observation data showed that Marius’ observations were independent of those of Galileo.

The publication of the Sidereus Nuncius was an absolute sensation and the book quickly sold out. Galileo went, almost literally overnight, from being a virtually unknown, middle aged, Northern Italian, professor of mathematics to the most celebrated astronomer in the whole of Europe. However, not everybody celebrated or accepted the truth of his discoveries and that not without reason. Firstly, any new scientific discovery needs to be confirmed independently by other. If Simon Marius had also published early in 1610 things might have been different but he, for whatever reasons, didn’t publish his Mundus Jovialis (The World of Jupiter) until 1614. Secondly there was no scientific explanation available that explained how a telescope functioned, so how did anyone know that what Galileo and others were observing was real? Thirdly, and this is a very important point that often gets ignored, the early telescopes were very, very poor quality suffering from all sorts of imperfections and distortions and it is almost a miracle that Galileo et al discovered anything with these extremely primitive instruments.

As I stated in the last episode, the second problem was solved by Johannes Kepler in 1611 with the publication of his Dioptrice.


A book that Galileo, always rather arrogant, dismissed as unreadable. This was his triumph and nobody else was going to muscle in on his glory. The third problem was one that only time and improvements in both glass making and the grinding and polishing of lenses would solve. In the intervening years there were numerous cases of new astronomical discoveries that turned out to be artefacts produced by poor quality instruments.

The first problem was the major hurdle that Galileo had to take if he wanted his discoveries to be taken seriously. Upon hearing of Galileo discoveries, Johannes Kepler in Prague immediately put pen to paper and fired off a pamphlet, Dissertatio cum Nuncio Sidereo (Conversation with the Starry Messenger) congratulating Galileo, welcoming his discoveries and stating his belief in their correctness, which he sent off to Italy. Galileo immediately printed and distributed a pirate copy of Kepler’s work, without even bothering to ask permission, it was after all a confirmation from the Imperial Mathematicus and Kepler’s reputation at this time was considerably bigger than Galileo’s.

Johannes Kepler, Dissertatio cum Nuncio sidereo… (Frankfurt am Main, 1611)

A reprint of Kepler’s letter to Galileo, originally issued in Prague in 1610

However, Kepler’s confirmations were based on faith and not personal confirmatory observations, so they didn’t really solve Galileo’s central problem. Help came in the end from the Jesuit astronomers of the Collegio Romano.

Odo van Maelcote and Giovanni Paolo Lembo had already been making telescopic astronomical observations before the publication of Galileo’s Sidereus Nuncius. Galileo also enjoyed good relations with Christoph Clavius (1538–1612), the founder and head of the school of mathematics at the Collegio Romano, who had been instrumental in helping Galileo to obtain the professorship in Padua. Under the direction of Christoph Grienberger (1561–1636), soon to be Clavius’ successor as professor for mathematics at the Collegio, the Jesuit astronomers set about trying to confirm all of Galileo’s discoveries. This proved more than somewhat difficult, as they were unable, even with Galileo’s assistance via correspondence, to produce an instrument of sufficient quality to observe the moons of Jupiter. In the end Antonio Santini (1577–1662), a mathematician from Venice, succeeded in producing a telescope of sufficient quality for the task, confirmed for himself the existence of the Jupiter moons and then sent a telescope to the Collegio Romano, where the Jesuit astronomers were now also able to confirm all of Galileo’s discovery. Galileo could not have wished for a better confirmation of his efforts, nobody was going to doubt the word of the Jesuits.

In March 1611 Galileo travelled to Rome, where the Jesuits staged a banquet in his honour at which Odo van Maelcote held an oration to the Tuscan astronomer. Galileo’s strategy of dedicating the Sidereus Nuncius to Cosimo de Medici and naming the four moons the Medicean Stars paid off and he was appointed court mathematicus and philosophicus in Florence and professor of mathematics at the university without any teaching obligations; Galileo had arrived at the top of the greasy pole but what goes up must, as we will see, come down.





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