Category Archives: Renaissance Science

Renaissance science – XXVII

Early on in this series I mentioned that a lot of the scientific developments that took place during the Renaissance were the result of practical developments entering the excessively theoretical world of the university disciplines. This was very much the case in the mathematical sciences, where the standard English expression for the Renaissance mathematicus is mathematical practitioner. In this practical world, areas that we would now regard as separate disciples were intertwined is a complex that the mathematical practitioners viewed as one discipline with various aspects, this involved astronomy, cartography, navigation, trigonometry, as well as instrument and globe making. I have already dealt with trigonometry, cartography and astronomy and will here turn my attention to navigation, which very much involved the other areas in that list.

The so-called Age of Discovery or Age of Exploration, that is when Europeans started crossing the oceans and discovering other lands and other cultures, coincides roughly with the Renaissance and this was, of course the main driving force behind the developments in navigation during this period. Before we look at those developments, I want to devote a couple of lines to the terms Age of Discovery and Age of Exploration. Both of them imply some sort of European superiority, “you didn’t exist until we discovered you” or “your lands were unknown until we explored them.” The populations of non-European countries and continents were not sitting around waiting for their lands and cultures to be discovered by the Europeans. In fact, that discovery very often turned out to be highly negative for the discovered. The explorers and discoverers were not the fearless, visionary heroes that we tend to get presented with in our schools, but ruthless, often brutal chancers, who were out to make a profit at whatever cost.  This being the case the more modern Contact Period, whilst blandly neutral, is preferred to describe this period of world history.

As far as can be determined, with the notable exception of the Vikings, sailing in the Atlantic was restricted to coastal sailing before the Late Middle Ages. Coastal sailing included things such as crossing the English Channel, which, archaeological evidence suggests, was done on a regular basis since at least the Neolithic if not even earlier. I’m not going to even try to deal with the discussions about how the Vikings possibly navigated. Of course, in other areas of the world, crossing large stretches of open water had become common place, whilst the European seamen still clung to their coast lines. Most notable are the island peoples of the Pacific, who were undertaking long journeys across the ocean already in the first millennium BCE. Arab and Chinese seamen were also sailing direct routes across the Indian Ocean, rather than hugging the coastline, during the medieval period. It should be noted that European exploited the navigation skills developed by these other cultures as they began to take up contact with the other part of the world. Vasco da Gamma (c. 1460–1524) used unidentified local navigators to guide his ships the first time he crossed the Indian Ocean from Africa to India. On his first voyage of exploration of the Pacific Ocean from 1768 to 1771, James Cook (1728–1779) used the services of the of the Polynesian navigator, Tupaia (c. 1725–1770), who even drew a chart, in cooperation with Cook, Joseph Banks, and several of Cooks officer, of his knowledge of the Pacific Ocean. 

Tupaia’s map, c. 1769 Source: Wikimedia Commons

There were two major developments in European navigation during the High Middle Ages, the use of the magnetic compass and the advent of the Portolan chart. The Chinese began to use the magnetic properties of loadstone, the mineral magnetite, for divination sometime in the second century BCE. Out of this they developed the compass needle over several centuries. It should be noted that for the Chinese, the compass points South and not North. The earliest Chinese mention of the use of a compass for navigation on land by the military is before 1044 CE and in maritime navigation in 1117 CE.

Diagram of a Ming Dynasty (1368–1644) mariner’s compass Source: Wikimedia Commons

Alexander Neckam (1157–1219) reported the use of the compass for maritime navigation in the English Channel in his manuscripts De untensilibus and De naturis rerum, written between 1187 and 1202.

The sailors, moreover, as they sail over the sea, when in cloudy whether they can no longer profit by the light of the sun, or when the world is wrapped up in the darkness of the shades of night, and they are ignorant to what point of the compass their ship’s course is directed, they touch the magnet with a needle, which (the needle) is whirled round in a circle until, when its motion ceases, its point looks direct to the north.

This and other references to the compass suggest that it use was well known in Europe by this time.

A drawing of a compass in a mid 14th-century copy of Epistola de magnete of Peter Peregrinus. Source: Wikimedia Commons

The earliest reference to maritime navigation with a compass in the Muslim world in in the Persian text Jawāmi ul-Hikāyāt wa Lawāmi’ ul-Riwāyāt (Collections of Stories and Illustrations of Histories) written by Sadīd ud-Dīn Muhammad Ibn Muhammad ‘Aufī Bukhārī (1171-1242) in 1232. There is still no certainty as to whether there was a knowledge transfer from China to Europe, either direct or via the Islamic Empire, or independent multiple discovery. Magnetism and the magnetic compass went through a four-hundred-year period of investigation and discovery until William Gilbert (1544–1603) published his De magnete in 1600. 

De Magnete, title page of 1628 edition Source: Wikimedia Commons

The earliest compasses used for navigation were in the form of a magnetic needle floating in a bowl of water. These were later replaced with dry mounted magnetic needles. The first discovery was the fact that the compass needle doesn’t actually point at the North Pole, the difference is called magnetic variation or magnetic declination. The Chinese knew of magnetic declination in the seventh century. In Europe the discovery is attributed to Georg Hartmann (1489–1564), who describes it in an unpublished letter to Duke Albrecht of Prussia. However, Georg von Peuerbach (1423–1461) had already built a portable sundial on which the declination for Vienna is marked on the compass.

NIMA Magnetic Variation Map 2000 Source: Wikimedia Commons

There followed the discovery that magnetic declination varies from place to place. Later in the seventeenth century it was also discovered that declination also varies over time. We now know that the Earth’s magnetic pole wanders, but it was first Gilbert, who suggested that the Earth is a large magnet with poles. The next discovery was magnetic dip or magnetic inclination. This describes the fact that a compass needle does not sit parallel to the ground but points up or down following the lines of magnetic field. The discovery of magnetic inclination is also attributed to Georg Hartmann. The sixteenth century English, seaman Robert Norman rediscovered it and described how to measure it in his The Newe Attractive (1581) His work heavily influenced Gilbert. 

Illustration of magnetic dip from Norman’s book, The Newe Attractive Source: Wikimedia Commons

The Portolan chart, the earliest known sea chart, emerged in the Mediterranean in the late thirteenth century, not long after the compass, with which it is closely associated, appeared in Europe. The oldest surviving Portolan, the Carta Pisana is a map of the Mediterranean, the Black Sea and part of the Atlantic coast.

Source: Wikimedia Commons

The origins of the Portolan chart remain something of a mystery, as they are very sophisticated artifacts that appear to display no historical evolution. A Portolan has a very accurate presentation of the coastlines with the locations of the major harbours and town on the coast. Otherwise, they have no details further inland, indicating that they were designed for use in coastal sailing. A distinctive feature of Portolans is their wind roses or compass roses located at various points on the charts. These are points with lines radiating outwards in the sixteen headings, on later charts thirty-two, of the mariner’s compass.

Central wind rose on the Carta Pisana

Portolan charts have no latitude or longitude lines and are on the so-called plane chart projection, which treats the area being mapped as flat, ignoring the curvature of the Earth. This is alright for comparatively small areas, such as the Mediterranean, but leads to serious distortion, when applied to larger areas.

During the Contact Period, Portolan charts were extended to include the west coast of Africa, as the Portuguese explorers worked their way down it. Later, the first charts of the Americas were also drawn in the same way. Portolan style charts remained popular down to the eighteenth century.

Portolan chart of Central America c. 1585-1595 Source:

A central problem with Portolan charts over larger areas is that on a globe constant compass bearings are not straight lines. The solution to the problem was found by the Portuguese cosmographer Pedro Nunes (1502–1578) and published in his Tratado em defensam da carta de marear (Treatise Defending the Sea Chart), (1537).

Image of Portuguese mathematician Pedro Nunes in Panorama magazine (1843); Lisbon, Portugal. Source: Wikimedia Commons

The line is a spiral known as a loxodrome or rhumb lines. Nunes problem was that he didn’t know how to reproduce his loxodromes on a flat map.

Image of a loxodrome, or rhumb line, spiraling towards the North Pole Source: Wikimedia Commons

The solution to the problem was provided by the map maker Gerard Mercator (1512–1594), when he developed the so-called Mercator projection, which he published as a world map, Nova et Aucta Orbis Terrae Descriptio ad Usum Navigantium Emendate Accommodata (New and more complete representation of the terrestrial globe properly adapted for use in navigation) in 1569.

Source: Wikimedia Commons
The 1569 Mercator world map Source: Wikimedia Commons.

On the Mercator projection lines of constant compass bearing, loxodromes, are straight lines. This however comes at a price. In order to achieve the required navigational advantage, the lines of latitude on the map get further apart as one moves away from the centre of projection. This leads to an area distortion that increases the further north or south on goes from the equator. This means that Greenland, slightly more than two million square kilometres, appear lager than Africa, over thirty million square kilometres.

Mercator did not publish an explanation of the mathematics used to produce his projection, so initially others could reproduce it. In the late sixteenth century three English mathematicians John Dee (1527–c. 1608), Thomas Harriot (c. 1560–1621), and Edward Wright (1561–1615) all individually worked out the mathematics of the Mercator projection. Although Dee and Harriot both used this knowledge and taught it to others in their respective functions as mathematical advisors to the Muscovy Trading Company and Sir Walter Raleigh, only Wright published the solution in his Certaine Errors in Navigation, arising either of the Ordinarie Erroneous Making or Vsing of the Sea Chart, Compasse, Crosse Staffe, and Tables of Declination of the Sunne, and Fixed Starres Detected and Corrected. (The Voyage of the Right Ho. George Earle of Cumberl. to the Azores, &c.) published in London in 1599. A second edition with a different, even longer, title was published in the same year. Further editions were published in 1610 and 1657. 

Source: Wikimedia Commons
Wright explained the Mercator projection with the analogy of a sphere being inflated like a bladder inside a hollow cylinder. The sphere is expanded uniformly, so that the meridians lengthen in the same proportion as the parallels, until each point of the expanding spherical surface comes into contact with the inside of the cylinder. This process preserves the local shape and angles of features on the surface of the original globe, at the expense of parts of the globe with different latitudes becoming expanded by different amounts. The cylinder is then opened out into a two-dimensional rectangle. The projection is a boon to navigators as rhumb lines are depicted as straight lines. Source: Wikimedia Commons

His mathematical solution for the Mercator projection had been published previously with his permission and acknowledgement by Thomas Blundeville (c. 1522–c. 1606) in his Exercises (1594) and by William Barlow (died 1625) in his The Navigator’s Supply (1597). However, Jodocus Hondius (1563–1612) published maps using Wright’s work without acknowledgement in Amsterdam in 1597, which provoked Wright to publish his Certaine Errors. Despite its availability, the uptake on the Mercator projection was actually very slow and it didn’t really come into widespread use until the eighteenth century.

Wright’s “Chart of the World on Mercator’s Projection” (c. 1599), otherwise known as the Wright–Molyneux map because it was based on the globe of Emery Molyneux (died 1598) Source: Wikimedia Commons

Following the cartographical trail, we have over sprung a lot of developments in navigation to which we will return in the next episode. 


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

Renaissance science – XXVI

I wrote a whole fifty-two-part blog post series on The Emergence of Modern Astronomy, much of which covered the same period as this series, so I’m not going to repeat it here. However, an interesting question is, did the developments in astronomy during the Humanist Renaissance go hand in hand with humanism and to what extent, or did the two movements run parallel in time to each other without significant interaction? 

The simple answer to my own questions is yes, humanism and the emergence of modern astronomy were very closely interlinked in the period between 1400 and the early seventeenth century. This runs contrary to a popular conception that the Humanist Renaissance was purely literary and in no way scientific. In what follows I will briefly sketch some of that interlinking. 

To start, two of the driving forces behind the desire to renew and improve astronomy, the rediscovery of Ptolemaic mathematics-based cartography and the rise in importance of astrology were very much part of the Humanist Renaissance, as I have already documented in earlier episodes of this series. It is not a coincidence that many of the leading figures in the development of modern astronomy were also involved, either directly or indirectly, in the new cartography. Also, nearly all of them were active astrologers. 

Turning to the individual astronomers, the man, who kicked off the debate on the astronomical status of comets, a debate that, I have shown, played a central role in the evolution of modern astronomy, Paolo dal Pozzo Toscanelli (1397–1482) a member of the Florentine circle of prominent humanist scholars that included Filippo Brunelleschi, Marsilio Ficino, Leon Battista Alberti and Cardinal Nicolaus Cusanus, all of whom have featured in earlier episodes of this series.

Paolo dal Pozzo Toscanelli Source: Wikimedia Commons

Toscanelli, who is best known as the cosmographer, who supplied Columbus with a misleading world map, was one of those who met the Neoplatonic philosopher Georgius Gemistus Pletho (c. 1355–c. 1452) at the Council of Florence. Pletho introduced Toscanelli to the work of the Greek geographer Strabo (c. 64 BCE–c. 24 CE), which was previously unknown in Italy. 

Turning to the University of Vienna and the so-called First Viennese School of Mathematics, already during the time of Johannes von Gmunden (c. 1380–1442) and Georg Müstinger (before 1400–1442), Vienna had become a major centre for the new cartography as well as astronomy. However, it is with the next generation that we find humanist scholars at work. Toscanelli’s unpublished work on comets might have remained unknown if it hadn’t been for Georg von Peuerbach (1423–1461). As a young man Peuerbach had travelled extensively in Italy and become acquainted with the circle of humanists to which Toscanelli belonged. He shared an apartment in Rome with Cusanus and personally met and exchanged ideas with Toscanelli. Returning to Vienna he lectured on poetics and took a leading role in reviving classical Greek and Latin literature, a central humanist concern. Today he is, of course, better known for his work as an astronomer and as the teacher of Johannes Müller, better known Regiomontanus.

First page of Peuerbach’s Theoricae novae planetarum in the Manuscript Krakau, Biblioteca Jagiellońska, Ms. 599, fol. 1r (15th century) Source: Wikimedia Commons

Regiomontanus (1436–1476) became a member of the familia (household) of the leading Greek humanist scholar Basilios Bessarion (1403–1472), a pupil of Pletho. He travelled with Bessarion through Italy, working as his librarian finding and copying Latin and Greek manuscripts on astronomy, astrology and mathematics for Bessarion’s library. Bessarion had taught him Greek for this purpose. Leaving Bessarion’s service Regiomontanus served as librarian for the humanist scholars, János Vitéz Archbishop of Esztergom (c. 1408–1472) a friend of Peuerbach’s and then Matthias Corvinus (1443–1490) King of Hungary. 

Regiomontanus woodcut from the 1493 Nuremberg Chronicle Source: Wikimedia Commons

When Regiomontanus left Hungary for Nürnberg he took a vast collection of Geek and Latin manuscripts with him, with the intention of printing them and publishing them. At the same time applying humanist methods of philology to free them of their errors accumulated through centuries of copying and recopying. A standard humanist project as was the Epitome of Ptolemaeus that he and Peuerbach produced under the stewardship of Bessarion.

The so-called Second Viennese School of mathematics was literally founded by a humanist, when Conrad Celtis (1459–1508) took the professors of mathematics Andreas Stiborius (1464–1515) and Johann Stabius (before 1468–1522), along with the student Georg Tanstetter (1482–1535) from Ingolstadt to Vienna, where he founded his Collegium poetarum et mathematicorum, that is a college for poetry and mathematics, in 1497. Ingolstadt had established the first ever German chair for mathematics to teach astrology to medical students, also basically a humanist driven development.

Conrad Celtis: In memoriam by Hans Burgkmair the Elder, 1507
Source: Wikimedia Commons

The wind of humanism was strong in Vienna, where Peter Apian (1495–1552) was Tanstetter’s star pupil becoming like his teacher a cosmographer, returning to Ingolstadt, where his star pupil was his own son Philipp (1531–1589), like his father a cosmographer. Philipp became professor in Tübingen, where he was Michael Mästlin’s teacher, instilling him with the Viennese humanism. As should be well known Mästlin was Kepler’s teacher.

Source: Wikimedia Commons

Back-tracking, we must consider the central figure of the emergence of modern astronomy, Nicolaus Copernicus (1473–1543). There are no doubts about Copernicus’ humanist credentials.

Copernicus holding lily-of-the-valley: portrait in Nicolaus Reusner’s Icones (1587) Source: Wikimedia Commons

He initially studied at the University of Krakow, the oldest humanist university in Europe north of the Italian border. He continued his education at various North Italian humanist universities, where he continued to learn his astronomy from the works of Peuerbach and Regiomontanus (as he had already done in Krakow) under the supervision of Domenico Maria da Novara (1454–1504) a Neoplatonist, who regarded himself as a student of Regiomontanus.

Domenico Maria da Novara Source Museo Galileo

In Northern Italy Copernicus received a full humanist education even learning Greek and some Hebrew. Establishing his humanist credentials, Copernicus published a Latin translation from the Greek of a set of 85 brief poems by the seventh century Byzantine historian Theophylact Somicatta, as Theophilacti scolastici Simocati epistolae morales, rurales et amatoriae interpretatione Latina in 1509. He also wrote some Greek poetry himself.


Copernicus is often hailed as the first modern astronomer but as many historians have pointed out, his initial intention, following the lead of Regiomontanus, was to restore the purity of Greek astronomy, a very humanist orientated undertaking. He wanted to remove the Ptolemaic equant point, which he saw as violating the Platonic ideal of uniform circular motion. De revolutionibus was modelled on Ptolemaeus’ Mathēmatikē Syntaxis, or more accurately on the Epytoma in almagesti Ptolemei of Peuerbach and Regiomontanus.

Tycho Brahe (1546–1601) was also heavily imbued with the humanist spirit. His elaborate, purpose-built home, laboratory, and observatory on the island of Hven, Uraniborg, was built in the style of the Venetian architect Andrea Palladio (1508–1580),

Portrait of Palladio by Alessandro Maganza Source: Wikimedia Commons

the most influential of the humanist architects, and was one of the earliest buildings constructed in the Renaissance style in Norther Europe.


All of the Early Modern astronomers from Toscanelli down to at least Tycho, and very much including Copernicus, were dedicated to the humanist ideal of restoring what they saw as the glory of classical astronomy from antiquity. Only incidentally did they pave a road that led away from antiquity to modern astronomy. 


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

Renaissance Science – XXV

It is generally acknowledged that the mathematisation of science was a central factor in the so-called scientific revolution. When I first came to the history of science there was widespread agreement that this mathematisation took place because of a change in the underlaying philosophy of science from Aristotelian to Platonic philosophy. However, as we saw in the last episode of this series, the renaissance in Platonic philosophy was largely of the Neoplatonic mystical philosophy rather than the Pythagorean, mathematical Platonic philosophy, the Plato of “Let no one ignorant of geometry enter here” inscribed over the entrance to The Academy. This is not to say that Plato’s favouring of mathematics did not have an influence during the Renaissance, but that influence was rather minor and not crucial or pivotal, as earlier propagated.

It shouldn’t need emphasising, as I’ve said it many times in the past, but Galileo’s infamous, Philosophy is written in this grand book, which stands continually open before our eyes (I say the ‘Universe’), but can not be understood without first learning to comprehend the language and know the characters as it is written. It is written in mathematical language, and its characters are triangles, circles and other geometric figures, without which it is impossible to humanly understand a word; without these one is wandering in a dark labyrinth, is not the origin of the mathematisation, as is falsely claimed by far too many, who should know better. One can already find the same sentiment in the Middle Ages, for example in Islam, in the work of Ibn al-Haytham (c. 965–c. 1040) or in Europe in the writings of both Robert Grosseteste (c. 1168–1253) and Roger Bacon, (c. 1219–c. 1292) although in the Middle Ages, outside of optics and astronomy, it remained more hypothetical than actually practiced. We find the same mathematical gospel preached in the sixteenth century by several scholars, most notably Christoph Clavius (1538–1612).

As almost always in history, it is simply wrong to look for a simple mono-casual explanation for any development. There were multiple driving forces behind the mathematisation. As we have already seen in various earlier episodes, the growing use and dominance of mathematics was driving by various of the practical mathematical disciplines during the Renaissance. 

The developments in cartography, surveying, and navigation (which I haven’t dealt with yet) all drove an increased role for both geometry and trigonometry. The renaissance of astrology also served the same function. The commercial revolution, the introduction of banking, and the introduction of double entry bookkeeping all drove the introduction and development of the Hindu-Arabic number system and algebra, which in turn would lead to the development of analytical mathematics in the seventeenth century. The development of astro-medicine or iatromathematics led to a change in the status of mathematic on the universities and the demand for commercial arithmetic led to the establishment of the abbacus or reckoning schools. The Renaissance artist-engineers with their development of linear perspective and their cult of machine design, together with the new developments in architecture were all driving forces in the development of geometry. All of these developments both separately and together led to a major increase in the status of the mathematical sciences and their dissemination throughout Europe. 

This didn’t all happen overnight but was a gradual process spread over a couple of centuries. However, by the early seventeenth century and what is generally regarded as the start of the scientific revolution the status and spread of mathematics was considerably different, in a positive sense, to what it had been at the end of the fourteenth century. Mathematics was now very much an established part of the scholarly spectrum. 

There was, however, another force driving the development and spread of mathematics and that was surprisingly the, on literature focused, original Renaissance humanists in Northern Italy. In and of itself, the original Renaissance humanists did not measure mathematics an especially important role in their intellectual cosmos. So how did the humanists become a driving force for the development of mathematics? The answer lies in their obsession with all and any Greek or Latin manuscripts from antiquity and also with the attitude to mathematics of their ancient role models. 

Cicero admired Archimedes, so Petrarch admired Archimedes and other humanists followed his example. In his Institutio Oratoria Quintilian was quite enthusiastic about mathematics in the training of the orator. However, both Cicero and Quintilian had reservations about how too intense an involvement with mathematics distracts one from the active life. This meant that the Renaissance humanists were, on the whole, rather ambivalent towards mathematics. They considered it was part of the education of a scholar, so that they could converse reasonably intelligently about mathematics in general, but anything approaching a deep knowledge of the subject was by and large frowned upon. After all, socially, mathematici were viewed as craftsmen and not scholars.

This attitude stood in contradiction to their manuscript collecting habits. On their journeys to the cloister libraries and to Byzantium, the humanists swept up everything they could find in Latin and/or Greek that was from antiquity. This meant that the manuscript collections in the newly founded humanist libraries also contained manuscripts from the mathematical disciplines. A good example is the manuscript of Ptolemaeus’ Geographia found in Constantinople and translated into Latin by Jacobus Angelus for the first time in 1406. The manuscripts were now there, and scholars began to engage with them leading to a true mathematical renaissance of the leading Greek mathematicians. 

We have already seen, in earlier episodes, the impact that the works of Ptolemaeus, Hero of Alexander, and Vitruvius had in the Renaissance, now I’m going to concentrate on three mathematicians Euclid, Archimedes, and Apollonius of Perga, starting with Archimedes. 

The works of Archimedes had already been translated from Greek into Latin by the Flemish translator Willem van Moerbeke (1215–1286) in the thirteenth century.

Archimedes Greek manuscript

He also translated texts by Hero. Although, he was an excellent translator, he was not a mathematician, so his translations were somewhat difficult to comprehend. Archimedes was to a large extent ignored by the universities in the Middle Ages. In 1530, Jacobus Cremonensis (c. 1400–c. 1454) (birth name Jacopo da San Cassiano), a humanist and mathematician, translated, probably at request of the Pope, Nicholas V (1397–1455), a Greek manuscript of the works of Archimedes into Latin. He was also commissioned to correct George of Trebizond’s defective translation of Ptolemaeus’ Mathēmatikē Syntaxis. It is thought that the original Greek manuscript was lent or given to Basilios Bessarion (1403–1472) and has subsequently disappeared.

Bessarion had not only the largest humanist library but also the library with the highest number of mathematical manuscripts. Many of Bessarion’s manuscripts were collected by Regiomontanus (1436–1476) during the four to five years (1461–c. 1465) that he was part of Bessarion’s household.

Basilios Bessarion Justus van Gent and Pedro Berruguete Source: Wikimedia Commons

When Regiomontanus moved to Nürnberg in 1471 he brought a large collection of mathematical, astronomical, and astrological manuscripts with him, including the Cremonenius Latin Archimedes and several manuscripts of Euclid’s Elements, that he intended to print and publish in the printing office that he set up there. Unfortunately, he died before he really got going and had only published nine texts including his catalogue of future intended publications that also listed the Cremonenius Latin Archimedes. 

The invention of moving type book printing was, of course, a major game changer. In 1482, Erhard Ratdolt (1447–1522) published the first printed edition of The Elements of Euclid from one of Regiomontanus’ manuscripts of the Latin translation from Arabic by Campanus of Novara (c. 1220–1296).

A page with marginalia from the first printed edition of Euclid’s Elements, printed by Erhard Ratdolt in 1482
Folger Shakespeare Library Digital Image Collection
Source: Wikimedia Commons

In 1505, a Latin translation from the Greek by Bartolomeo Zamberti (c. 1473–after 1543) was published in Venice in 1505, because Zamberti regarded the Campanus translation as defective. The first Greek edition, edited by Simon Grynaeus (1493–1541) was published by Jacob Herwegens in Basel in 1533.

Simon Grynaeus Source: Wikimedia Commons
Editio princeps of the Greek text of Euclid. Source

Numerous editions followed in Greek and/or Latin. The first modern language edition, in Italian, translated by the mathematician Niccolò Fontana Tartaglia (1499/1500–1557) was published in 1543.

Tartaglia Euclid Source

Other editions in German, French and Dutch appeared over the years and the first English edition, translated by Henry Billingsley (died 1606) with a preface by John Dee (1527–c. 1608) was published in 1570.

Title page of Sir Henry Billingsley’s first English version of Euclid’s Elements Source Wikimedia Commons

In 1574, Christoph Clavius (1538–1612) published the first of many editions of his revised and modernised Elements, to be used in his newly inaugurated mathematics programme in Catholic schools, colleges, and universities. It became the standard version of Euclid throughout Europe in the seventeenth century. In 1607, Matteo Ricci (1552–1610) and Xu Guanqui (1562–1633) published their Chinese translation of the first six books of Clavius’ Elements.

Xu Guangqi with Matteo Ricci (left) From Athanasius Kircher’s China Illustrata, 1667 Source: Wikimedia Commons

From being a medieval university textbook of which only the first six of the thirteen books were studied if at all, The Elements was now a major mathematical text. 

Unlike his Euclid manuscript, Regiomontanus’ Latin Archimedes manuscript had to wait until the middle of the sixteenth century to find an editor and publisher. In 1544, Ioannes Heruagius (Johannes Herwagen) (1497–1558) published a bilingual, Latin and Greek, edition of the works of Archimedes, edited by the Nürnberger scholar Thomas Venatorius (Geschauf) (1488–1551).

Thomas Venatorius Source

The Latin was the Cremonenius manuscript that Regiomontanus had brought to Nürnberg, and the Greek was a manuscript that Willibald Pirckheimer (1470–1530) had acquired in Rome.

Venatori Archimedes Source

Around the same time Tartaglia published partial editions of the works of Archimedes both in Italian and Latin translation. We will follow the publication history of Archimedes shortly, but first we need to go back to see what happened to The Conics of Apollonius, which became a highly influential text in the seventeenth century.

Although, The Conics was known to the Arabs, no translation of it appears to have been made into Latin during the twelfth-century scientific Renaissance. Giovanni-Battista Memmo (c. 1466–1536) produced a Latin translation of the first four of the six books of The Conics, which was published posthumously in Venice in 1537. Although regarded as defective this remained the only edition until the latter part of the century.

Memmo Apollonius Conics Source: Wikimedia Commons

We now enter the high point of the Renaissance reception of both Archimedes and Apollonius in the work of the mathematician and astronomer Francesco Maurolico (1494–1575) and the physician Federico Commandino (1509-1575). Maurolico spent a large part of his life improving the editions of a wide range of Greek mathematical works.

L0006455 Portrait of F. Maurolico by Bovis after Caravaggio Credit: Wellcome Library, London, via Wikimedia Commons

Unfortunately, he had problems finding sponsors and/or publishers for his work. His heavily edited and corrected volume of the works of Archimedes first appeared posthumously in Palermo in 1585. His definitive Latin edition of The Conics, with reconstructions of the fifth and sixth books, completed in 1547, was first published in 1654.

Maurolico corresponded with Christoph Clavius, who had visited him in Sicily in 1574, when the observed an annular solar eclipse together, and with Federico Commandino, although the two never met.

Federico Commandino produced and published a whole series of Greek mathematical works, which became something like standard editions.

Source: Wikimedia Commons

His edition of the works of Archimedes appeared in 1565 and his Apollonius translation in 1566.

Two of Commandino’s disciples were Guidobaldo del Monte (1545–1607) and Bernardino Baldi (1553–1617). 

Baldi wrote a history of mathematics the Cronica dei Matematici, which was published in Urbino in 1707. This was a brief summary of his much bigger Vite de’ mathematici, a two-thousand-page manuscript that was never published.

Bernadino Baldi Source: Wikimedia Commons
Source: Wikimedia Commons

Guidobaldo del Monte, an aristocrat, mathematician, philosopher, and astronomer

Guidobaldo del Monte Source: Wikimedia Commons

became a strong promoter of Commandino’s work and in particular the works of Archimedes, which informed his own work in mechanics. 

In the midst of that darkness Federico Commandino shone like the sun, for his learning he not only restored the lost heritage of mathematics but actually increased and enhanced it … In him seem to have lived again Archytas, Diophantus, Theodosius, Ptolemy, Apollonius, Serenus, Pappus and even Archimedes himself.

Guidobaldo. Liber Mechanicorum, Pesaro 1577, Preface
Source: Wikimedia Commons

When the young Galileo wrote his first essay on the hydrostatic balance, his theory how Archimedes actually detected the substitution of silver for gold in the crown made for King Hiero of Syracuse, he sent it to Guidobaldo to try and win his support and patronage. Guidobaldo was very impressed and got his brother Cardinal Francesco Maria del Monte (1549–1627), the de’ Medici family cardinal, to recommend Galileo to Ferinando I de’ Medici, Grand Duke of Tuscany, (1549–1609) for the position of professor of mathematics at Pisa University. Galileo worked together with Guidobaldo on various projects and for Galileo, who rejected Aristotle, Archimedes became his philosophical role model, who he often praised in his works. 

Galileo was by no means the only seventeenth century scientist to take Archimedes as his role model in pursuing a mathematical physics, for example Kepler used a modified form of Archimedes’ method of exhaustion to determine the volume of barrels, a first step to the development of integral calculus. The all pervasiveness of Archimedes in the seventeenth century is wonderfully illustrated at the end of the century by Sir William Temple, Jonathan Swift’s employer, during the so-called battle of the Ancients and Moderns. In one of his essays, Temple an ardent supporter of the superiority of the ancients over the moderns, asked if John Wilkins was the seventeenth century Archimedes, a rhetorical question with a definitively negative answer. 

During the Middle Ages Euclid was the only major Greek mathematician taught at the European universities and that only at a very low level. By the seventeenth century Euclid had been fully restored as a serious mathematical text and the works of both Archimedes and Apollonius had entered the intellectual mainstream and all three texts along with other restored Greek texts such as the Mathematical Collection of Pappus, also published by Commandino and the Arithmetica of Diophantus, another manuscript brought to Nürnberg by Regiomontanus and worked on by numerous mathematicians, became influential in development of the new sciences.  


Filed under History of Mathematics, History of Physics, History of science, Renaissance Science

Renaissance Science – XXIV

It might be considered rational to assume that during the period that is viewed as the precursor to the so-called scientific revolution, which is itself viewed as the birth of modern science, that the level of esotericism and the importance of the occult sciences would decline. However, the exact opposite is true, the Renaissance saw a historical highpoint in the popularity and practice of esotericism and the occult sciences. We have already seen how astro-medicine or iatromathematics came to dominate the practice of medicine in this period and horoscope astrology continued to be practiced by almost all astronomers till well into the seventeenth century. We also saw how, not just due to the efforts of Paracelsus, the practice and status of alchemy also reached a high point during this period. Now, I would like to take a look at the emergence of natural magic during this period and the processes that drove it.

There was nothing new about the supposed existence of magic in the Renaissance, but throughout the Christian era magic was associated with demonic forces. It was thought that people, who practiced magic, were calling on the power of the devil. Augustinus, who had been a practicing astrologer and believed that astrology worked, thought it could only do so through demonic forces thus his famous condemnation of the mathematici, by which he meant astrologers and not mathematicians. What was new in the Renaissance was the concept of a magic, natural magic, that was not dependent on demonic forces. This is the origin of the concept of the distinction between black magic and white magic, to use the more modern terms for it. Various groups of texts that found prominence in the Renaissance humanist search for authentic texts from antiquity were instrumental in this development. In roughly the order of there emergence they were the philosophy of Plato and in particular the work of the Neoplatonists from the third century CE, the Hermetic Corpus, and the Jewish Kabbalah. In the first two of these the humanist scholar Marsilio Ficino (1433–1499) played a pivotal role. 

Marsilio Ficino from a fresco painted by Domenico Ghirlandaio in the Tornabuoni Chapel, Santa Maria Novella, Florence Source: Wikimedia Commons

Ficino was the son of Diotifeci d’Angolo a physician whose patron was Cosimo de’ Medici (1389–1464) a major supporter of the humanist Renaissance. Ficino became a member of the Medici household and Cosimo remained his patron for his entire life, even appointing him tutor to his grandson Lorenzo de’ Medici (1449–1492).

Cosimo de’ Medici portrait by Jacopo Pontormo Source: Wikimedia Commons

At the Council of Florence (1438-1444), an attempt to heal the schism between the Orthodox and Catholic Churches, Cosimo de’ Medici became acquainted and enamoured with the Greek Neoplatonic philosopher Georgius Gemistus Pletho (C. 1355–c. 1450), who was also the teacher of Basileios Bessarion (1403–1472) another highly influential Renaissance scholar.

Portrait of Gemistus Pletho, detail of a fresco by Benozzo Gozzoli, Palazzo Medici Riccardi, Florence Source: Wikimedia Commons 

Returning home Cosimo decided to refound Plato’s Academy and appointed Ficino to head it, who then proceeded to learn Greek from Ioannis Argyropoulus (c. 1415–1487), another Greek, who came to Italy during the Council of Florence.

Ioannis Argyropoulos as depicted by Domenico Ghirlandaio Source: Wikimedia Commons

Today Plato is regarded as one of the greatest and most important of all Western philosophers, there is a saying that Plato is just footnotes to Socrates and Alfred North Whitehead (1861–1947) once quipped that Western philosophy is just footnotes to Plato, so it might seem strange to us that during the Renaissance Plato was virtually unknown in Europe. In the Early Middle Ages, the only one of Plato’s worked that was known in Latin was the Timaeus (c. 360 BCE) his speculations on the nature of the physical world, about which George Sarton infamously wrote in his A History of Science (Harvard University Press, 1959):

The influence of Timaeus upon later times was enormous and essentially evil. A large portion of Timaeus had been translated into Latin by Chalcidius, and that translation remained for over eight centuries the only Platonic text known in the Latin West. Yet the fame of Plato had reached them, and thus the Latin Timaeusbecame a kind of Platonic evangel which many scholars were ready to interpret literally. The scientific perversities of Timaeus were mistaken for scientific truths. I cannot mention any other work whose influence was more mischievous, except the Revelations of John the Devine. The apocalypse, however, was accepted as a religious book, the Timaeus as a scientific one; errors and superstition are never more dangerous than when offered to us under the cloak of science. 

George Sarton  A History of Science (Harvard University Press, 1959)

Strong stuff! Somehow Plato got ignored during the so-called Scientific Renaissance and unlike Aristotle his works were not translated into Latin at this time. In 1462 Cosimo de’ Medici supplied Ficino with Greek manuscripts of Plato’s work and commissioned him to translate them into into Latin, a task that he carried out by 1468-69, the works being published in 1484. Ficino also translated the work of many of the Neoplatonist in particular the work of Porphyry (c. 234–c. 305) and Plotinus (c. 204–270 CE). 

So, what does this revival in the philosophy of Plato have to do with magic, natural or otherwise? The answer lies in that which Sarton found so abhorrent in Plato’s philosophy of science. Plato’s philosophy of scienced is heavily laced with what can be simply described as a heavy dose of mysticism and it is this aspect of Plato’s philosophy that is strongly emphasised by the third century Neoplatonists. I’m not going to go into great detail as this blog post would rapidly turn into a monster, there have been numerous thick books written about the Timaeus alone but will only present a very brief sketch of the relevant concepts.

According to Plato the cosmos was created by the demiurge, the divine craftsman, as a single living entity, which he then endowed with a world soul. It was this concept of the Oneness of the cosmos that was at the core of the philosophy of the third century Neoplatonists and in Ficino’s own personal interpretation of Platonic thought. How this relates to natural magic, I will explain later after we have looked at Ficino’s translation of the Hermetic Corpus. 

In 1460, Leonardo de Candia Pistola, one of the agents Cosimo de’ Medici had sent out to search European monasteries for ancient manuscripts, returned to Tuscany with the so-called Corpus Hermeticum. This is a collection of seventeen Greek texts supposedly of great antiquity and written by Hermes Trismegistus a legendary Hellenistic creation combining elements of the Egyptian god Thoth and his Greek counterpart Hermes. Ficino interrupted his translation of Plato and immediately began translating the texts of the Corpus Hermeticum into Latin; he translated the first fourteen of the texts and Lodovico Lazzarelli (1447–1500) translated the other three.

Lodovico Lazzarelli (via his muse) presents the manuscript of Fasti christianae religionis to Ferdinand I of Aragon, king of Naples and Sicily. (Beinecke MS 391, f.6v) Source: Wikimedia Commons

There are other Hermetic texts most notably the Emerald Tablet an Arabic text first known in the eight or early nine century and the Asclepius already know in Latin during the Middle Ages. 

Once again, the subject is far to extensive for an analysis in a blog post, so I will only sketch a brief outline of the salient points. The hermetic texts are a complex mix of religious-philosophical magic texts, astrological texts, and alchemical texts. The religious-philosophical aspect has a strong similarity to the Platonic theory of the One, the cosmos as a single living entity. In hermeticism, God and the cosmos are one and the same thing. God is the All and at the same time the creator of the All. Hermeticists also believed in the principle of a prisca theologica, that there is a single true, original theology, which for Christian Hermeticists originates with Moses. They believed Hermes had his knowledge direct from Moses. A central tenet of Hermeticism was the macrocosm-microcosm theory, as above so below. Meaning the Earth is a copy of the heavens, astrology and alchemy are instances of the forces of the heavens working on the Earth. 

Macrocosm-Microcosm Lucas Jemnnis Museum Hermeticum (1625)

Combining Neoplatonic philosophy and Hermeticism, Renaissance humanists developed the concept of natural magic. Rather than a magic based on demonic influence, natural magic works by tapping directly into the forces of the cosmos that are the source of astrology and alchemy. 

The Kabbalah is a school of Jewish esoteric teaching that is supposed to explain the relationship between the unchanging, infinite, eternal God and the mortal, finite cosmos, God’s creation. Renaissance humanist believed in the ideal of the tres linguæ sacræ (the three holy languages)–Latin, Greek, and Hebrew–the languages needed for Biblical studies. The scholars of Hebrew stumbled across the Jewish Kabbalah and began to incorporate it into the Renaissance mysticism. Giovanni Pico della Mirandola (1463–1494) an Italian Renaissance nobleman and student of Ficino

Giovanni Pico della Mirandola portrait by Cristofano dell’Altissimo (c. 1525–1605) Source: Wikimedia Commons

founded or created a Christian Kabbalah, which he wove together with Platonism, Neoplatonism, Aristotelianism, and Hermeticism. A heady brew! Given his own personal philosophy, which included a form of natural magic that he called Theurgy, operation of the gods, I find it more than somewhat ironic that Pico is hailed as an early rejecter of astrology.

The Christian Kabbalah was developed by Pico’s most noted follower in this area, the German humanist, Johannes Reuchlin (1455–1522), who not only propagated the Christian Kabbalah but fiercely defended Jewish literature against the strong Anti-Semitic movement to ban and burn it in the early sixteenth century.

Johann Reuchlin, woodcut depiction from 1516 Source: Wikimedia Commons

He was a highly influential teacher of Hebrew and became professor for Hebrew at the University of Ingolstadt. Amongst his most notable students were his nephew Philip Melanchthon (1497–1560) (it was Reuchlin who suggested that Philip adopt the humanist name Melanchthon a Greek translation of his birth name, Schwartzerdt) and the Nürnberger reformer, Andreas Osiander (1498­–1522), who famously authored the Ad lectorum at the beginning of Copernicus’ De revolutionibus. Even Martin Luther consulted Reuchlin on Hebrew and read his texts on the Kabbalah, whilst disagreeing with him.

Hermeticism was adopted by many leading thinkers in the Early Modern Period including Giordano Bruno (1548–1600), Francesco Patrizi (1529–1597) (an influential and much discussed philosopher in the period, who is largely forgotten today except by specialists), and Robert Fludd (1574–1637), who notoriously disputed with Johannes Kepler, rejecting Kepler’s mathematics-based science for one based on what might be described as hermetic mandalas. Even Isaac Newton (1642–1727) processed a substantial collection of hermetic literature. 

The English Renaissance historian Frances Yates (1899–1981) argued in, her much praised, Giordano Bruno and the Hermetic Tradition (1964) that hermeticism played a central role in the emergence of heliocentric astronomy in the Early Modern Period. Even Copernicus appears to quote Hermes Trismegistus in his De revolutionibus in his hymn of praise of the Sun to justify its central position of the cosmos:

At rest, however, in the middle of everything is the sun. For in this most beautiful temple, who would place this lamp in another or better position than that from which it can light up the whole thing at the same time? For, the sun is not inappropriately called by some people the lantern of the universe, its mind by others, and its ruler by still others. [Hermes] Trismegistus labels it a visible god and Sophocles’ Electra, the all-seeing. 

Yates’ thesis is now largely rejected by historians of astronomy, but her book is still praised for making people aware of the extent of hermeticism in the Early Modern Period. It is difficult to assess if hermeticism had any direct or indirect influence on the development of science during the period, but it was certainly very present in the intellectual atmosphere of the period.

Before I turn to natural magic it is interesting to note that the highly influential, humanist scholar Isaac Casaubon (1559–1614), who through the much-propagated philological analysis of texts was able to show, at the beginning of the seventeenth century, that the Corpus Hermeticum was not as ancient as its supporters claimed but was created in the early centuries of the common era and was thus contemporaneous with the Neoplatonic texts. Casaubon’s analysis was largely ignored by the supporters of hermeticism in the seventeenth century.

Isaac Casaubon artist unknown Source: Wikimedia Commons

 As already stated above natural magic was the belief into the possibility to directly tap into the forces within the single, living, cosmic organism, of the Neoplatonists and Hermeticists, that were present in astrology and alchemy. One of the strongest propagators of natural magic was the German polymath Heinrich Cornelius Agrippa von Nettesheim (1486–1535).

Heinrich Cornelius Agrippa von Nettesheim Source: Wikimedia Commons

He presented his views on the topic in his widely read De Occulta Philosophia libri III (Three Books of Occult Philosophy) the first volume of which was published in Paris in 1531 and the full three volumes in Cologne in 1533.

Man inscribed in a pentagram, from Heinrich Cornelius Agrippa’s De Occulta Philosophia libri III . The signs on the perimeter represent the 5 visible planets in astrology. Source: Wikipedia Commons

In an earlier work, De incertitudine et vanitate scientiarum atque artium declamatio invectiva (Declamation Attacking the Uncertainty and Vanity of the Sciences and the Arts, Cologne 1527) he wrote the following explanation of natural magic:

Natural magic is that which having contemplated the virtues of all natural and celestial and carefully studied their order proceeds to make known the hidden and secret powers of nature in such a way that inferior and superior things are joined by an interchanging application of each to each: thus incredible miracles are often accomplished not so much by art as by nature, to whom this art is a servant when working at these things. For this reason magicians are careful explorers of nature, only directing what nature has formally prepared, uniting actives to passives and often succeeding in anticipating results; so that these things are popularly held to be miracles when they are really no more than anticipations of natural operations … therefore those who believe the operations of magic to be above or against nature are mistaken because they are only derived from nature and in harmony with it.

The other major figure of natural magic was the Italian polymath Giambattista della Porta (1535(?)–1615), a respected figure in the Renaissance scientific community, who authored the Magia Naturalis, first published as a single volume in 1558, which grew to twenty volumes by 1589.

Giambattista della Porta artist unknown Source: Wikimedia Commons

I have written an extensive blog post on della Porta and his book here, so I won’t add more here. He describes natural magic thus:

Magick is nothing else but the knowledge of the whole course of Nature. For, whilst we consider the Heavens, the Stars, the Elements, how they moved, and how they changed, by this means we find out the hidden secrecies of living creatures, of plants, of metals, and of their generation and corruption; so that this whole science seems merely to depend upon the view of Nature … This Art, I say, is full of much virtue, of many secret mysteries; it openeth unto us the properties and qualities of hidden thins, and the knowledge of the whole course of Nature; and it teacheth us by the agreement and the disagreement of things, either so to sunder them, or else to lay them so together by the mutual and fit applying of one thing to another, as thereby we do strange works, such as the vulgar sort call miracles, and such men can neither well conceive, nor sufficiently admire … Wherefore, as many of you as come to behold Magic, must be perswaded that the works of Magick are nothing else but the works of Nature, whose dutiful hand-maid magick is.

Both Agrippa and della Porta were widely read and important parts of the philosophical debates around science in the Renaissance but it is difficult to say whether their concept of natural magic any influence on the development of science in this period. It can and has been argued that because natural magic was inductive by nature that it influenced the adoption of induction in the scientific method in the seventeenth century. There exists a debate amongst historians to what extent Francis Bacon was or was not influenced by hermeticism and natural magic. Others such as Bruno and John Dee certainly were. Dee included magic as one of the mathematical disciplines in his Mathematicall Praeface to Henry Billingsley’s English translation of The Elements of Euclid.

It probably seems strange to include a long essay on what is basically occult philosophy in a series on Renaissance science, but one can’t ignore the fact that Neoplatonism, hermeticism and natural magic were all separately and in various combinations an integral part of the intellectual debate of the period between fourteen and seventeen hundred.


Filed under History of Alchemy, History of Astrology, History of science, Renaissance Science

Renaissance Science – XXIII

Without doubt, one of the most eccentric and certainly one of the most controversial figures of the entire Early Modern period was the iconoclastic Swiss physician Theophrastus von Hohenheim (c. 1493–1541), more popularly known as Paracelsus. Trying to write about Paracelsus is complicated by the fact that he is the source of numerous myths and legends. Even if one resorts to the old maxim of Sergeant Joe Friday in the 1950s American radio series Dragnet, “just the facts ma’am”,* you run into problems. Every fact presented by one Paracelsus researcher has been disputed by at least one other Paracelsus researcher, so I shall just give a sketch of the generally accepted facts about his life then concentrate on his medical theories and their impact in the Early Modern Period.

He was born Theophrastus von Hohenheim the son of Wilhelm Bombast von Hohenheim, an illegitimate descendent of a Swabian aristocratic family, and his wife a bondswoman of the local Benedictine monastery in Einsiedeln in the canton of Schwyz in Switzerland, probably in 1493 or 94. Wilhelm held a Master’s degree in medicine and was physician to the mining community in Einsiedeln. Following the early death of his mother, probably around 1502, his father moved to Villach in Austria, another mining community. 

Aureoli Theophrasti ab Hohenheim. Reproduction, 1927, of etching by A. Hirschvogel, 1538. Source: Wikimedia Commons

It is probable that Theophrastus received his early education from his father in medicine, mining, minerology, botany, and alchemy. Almost nothing in known about his further education other than that he was registered as a Artzney Doctor(Doctor of Medicine) in Strasbourg in 1525 and a year later in Basel he testified that his doctorate was from the University of Ferrara. There is, however, no other evidence to support this claim. He seems to have travelled widely throughout Europe in his youth but, once again, there are no real details of this part of his life. 

In 1525 he settled in Salzburg as a physician, but probably because of the unrest caused by the German Peasant’s War he moved to Strasbourg in 1526. In 1527, he received what should have been a major boost in his career when he was called to Basel to treat the leading humanist publisher Johann Froben (c. 1460–1527), who had been written off by his own doctors, apparently because of a gangrenous foot. During six weeks of treatment in early 1527 Theophrastus succeeded in bringing relief to the publisher and for his efforts was richly rewarded and appointed town physician of Basel. This appointment included not just the right but the obligation to hold lectures at the university. Although he probably didn’t realise it at the time, Theophrastus had reached the apex of his formal career as physician.

1493 woodcut of Basle, from the Nuremberg Chronicle Source: Wikimedia Commons

During his time in Basel, Theophrastus came into contact with many leading humanist scholars, including Erasmus, who had worked for Froben and with whom he carried out a correspondence on theological issues.

Theophrastus’ time in Basel was to put it mildly stormy. He clashed head on with the local medical establishment and began his career as medical iconoclast declaring war on the conventional university medical teachings. He held his lectures in German instead of Latin to make them accessible to everyman and rejected the authority of the standard medical texts, preferring experience and empiricism to book learning. This behaviour reached a high point when he burnt a copy of Avicenna’s Canon of Medicine, probably the most important university medical textbook, on the Basel marketplace in the St John’s Eve fire on 23 June 1527. In February 1528 his brief career as an establishment physician came to an end and Theophrastus left Basel for what would turn out to be a life as an itinerant physician until his death in 1541. 

In 1529, Theophrastus moved to the city of Nürnberg, in the early sixteenth century, one of the richest cities in Europe and a major centre for both the mathematical science including astrology and medicine. His aim was to establish himself in the thriving and lucrative market for medical books. Here he decided to enter the rumbling syphilis debate. The disease had first appeared in Europe in the late fifteenth century and in fact only obtained the name, syphilis, from Girolamo Fracastoro (c. 1477–1553) in 1530. In 1529, there were two competing “cures” for syphilis, mercury, and guaiac wood. Theophrastus took up arms for mercury and against guaiac wood. He published one short pamphlet and a longer text on the topic with success. Unfortunately, the import from guaiacum wood from Brazil was financed by the Fugger banking house and the influential Leipziger physician Heinrich Stromer von Auerbach, a Fugger client, persuaded the Nürnberger medical establishment to block a planned major work from Theophrastus on the subject. Stromer’s influence throughout the German medical establishment served to effectively end Theophrastus’ medical publishing career before it had really started.

Heinrich Stromer von Auerbach Source: Wikimedia Commons

This medical publishing block led to Theophrastus adopting the name Paracelsus, a toponym for Hohenheim, for his future publication. In late 1529, he published an astrological pamphlet under the name Theophrastus Paracelsus and a short tract on the Comet of 1531 simply under the name Paracelsus. He proved to be a fairly successful astrological author and the majority of his publication up till his death were astrological.

From now on Theophrastus, blocked by the medical establishment was forced to live from treating rich private patient. He had a brief change of fortune in 1536, when he succeeded in getting his Die große Wundarzney (Great Book of Surgery) published by Heinrich Steiner (before 1500–1548) in Augsburg. The book was a success with, to Theophrastus’ annoyance, pirate editions appearing in both Ulm and Frankfurt in the same year. It remained a much-read reference work for more than a century. Theophrastus’ live continued to go downhill until his relatively early death in 1541.

Title page from ‘Der grossen Wundartzney’ (Great Surgery Book, 1536) by the Swiss alchemist and physician Paracelsus (1493-1541). Source

By the time of his death Theophrastus could be regarded as a failure. He had manged to publish little in the way of medical literature and apart from his brief time in Basel had held no important medical positions. He had succeeded in antagonising and alienating the medical establishment and was better known for his scandals than for any contributions to medicine. If his story had ended there, he would have become a mere footnote in the history of medicine as the man, who had publicly burnt a medical textbook on St John’s Eve in Basel in 1527. However, his story experienced a remarkable posthumous renaissance, which began about twenty years after his death.

Theophrastus had written a large number of books and tracts outlining his heterodox medical philosophy, none of which were published in his lifetime. Beginning in 1560, what might be termed his fan club–Adam von Bodenstein (1528–1577), Michael Toxites (1514–1581), Gerhard Dorn (c. 1530–1584), all of them physicians and alchemists–began to publish these texts, a process that culminated in the publication of a ten-volume edition of his medicinal and philosophical treatises under the title Bucher und Schriften by Johann Huser (c. 1545–1600) in Basel from 1598 to 1591. Huser’s edition of Theophrastus’ surgical publications appeared posthumously in 1605. It is in the last third of the sixteenth century that Paracelsian medicine became a serious discipline but what was it?

Paracelsus’ medical philosophy was a complex melange of religion, astrology, alchemy, and straight forward weirdness. He was first and foremost deeply religious and fundamentally Christian. He regarded himself, above everything else, as a religious reformer and a prophet. His religious stance was at the core of his rejection of the medicine taught at the European medieval universities. Greek and Islamic medicine were both heathen and thus to be rejected. Paracelsus insisted that his medicine was one hundred percent Christian. His rejection of Greek knowledge, of course, cost him any support he might have received from the humanists, who completely rejected him. 

At the centre of his philosophy was the macrocosm/microcosm, as above so below, concept that lay at the heart of the justification for astrology. This viewed the human body as a miniature model of the cosmos, the one affecting the other. Paracelsus took this one step further believing that all the minerals found in the world were found in another form within the human body.  This tied up with his concept of alchemy.

Paracelsus’ alchemy was not the alchemy of transmuting base metals into gold and silver but a medical alchemy. This was not a new thing, The Franciscan alchemist Jean de Roquetaillade, also known as John of Rupescissa (c. 1310–c. 1368) had emphasised the use of distillation to produce medicinal elixirs in his De Consideratione Quintae Essentiae (On the Consideration of the Quintessence of all Things).

Manuscript of Rupescissa c. 1350

This very popular text was reworked and integrated into the Pseudo-Lullian Liber de secretis naturae (Book of the Secrets of Nature). Paracelsus knew both works well. Believing like cures like, Paracelsus developed alchemical mineral cures that would act upon the minerals he believed to be in the body. He also believed that the organs of the body were organic alchemical apparatuses, there being an alchemical furnace at the centre of the body. Philosophically, borrowing from the Aristotelian belief that all metals originated from two principles present in different quantities, which Abu Mūsā Jābir ibn Hayyān named Mercury and Sulphur, in the eighth century. He believed that all matter consisted of three principles, his tria prima, Mercury, Sulphur, and Salt. A tripartite concept mirroring the Holy Trinity. I’m not going to go any deeper into this aspect of his alchemy or how it related to the traditional four element matter theory, but I will point out that it eventually led to the phlogiston theory in the seventeenth century. 

It was Paracelsus’ medical alchemy that his followers took up during the posthumous renaissance of his work, rechristening it chymiatria or iatrochemistry. This renaissance mostly took place not in the universities, the university professors of medicine rejecting the book burning iconoclast, but on the courts of various European rulers. First and foremost, Ernst of Bayern (1554­–1611), archbishop of Cologne, who was Johan Huser’s patron. Earlier the elector Palatine Ottheinrich (1502–1559) had been an enthusiastic supporter of Paracelsus. Later the Holy Roman Emperor Rudolf II (1552–1612), Wolfgang II von Hohenlohe (1546–1610), and Moritz von Hessen-Kassel (1572–1632) were all important patrons of Paracelsian alchemy. The University of Marburg boasts that they have the world’s first professorship for chemistry, but, in fact, the chair founded by Moritz von Hessen-Kassel, with the appointment of Johannes Hartmann (1561–1638) in 1609, was for Paracelsian iatrochemistry. 

Johannes Hartmann Source: Wikimedia Commons

The chair in Marburg was followed in the seventeenth century by several other new chairs all of them being chymiatria, and closely connected with the medical departments, rather than what is now known as chemistry. However, this adoption of Paracelsian chymiatria marks two different developments. Firstly, it is the beginning of pharmacology, of which Paracelsus is often called the founder. In Germany many pharmacies are still named after him. Secondly, it is an important development in the transition from alchemy to modern chemistry, a process that took place throughout the seventeenth and eighteenth centuries, with chemists, in the modern sense, in the eighteenth century strongly denying that their discipline ever had anything to do with alchemy. 

There were notable cases of scholars in the seventeenth century adopting and contributing to these developments in chymiatria, whilst stridently distancing themselves from Paracelsus and his “magic”. One notable example is Andreas Libavius (c.1550–1616), whose Alchymia (1597 is often cited as the first chemistry textbook.

Source: Wikimedia Commons

In his rejection of Paracelsus, he refers back to Pseudo-Lull and other medieval sources, claiming that Paracelsus was merely derivative. Another chemically inclined rejector of Paracelsus was Jan Baptist van Helmont (1580–1644). The heated debates between the Paracelsians, the convention physicians who rejected his alchemical medicine and those who accepted it, but vehemently rejected the man actually helped to spread his ideas. 

L0003194 Portrait of J.B. van Helmont, Aufgang…1683 Credit: Wellcome Library, London. Wellcome Images Portrait of J.B. van Helmont. Engraving Aufgang der Artzney-Kunst… Jean Baptiste van Helmont Published: 1683 Copyrighted work available under Creative Commons Attribution only licence CC BY 4.0

One highly influential Paracelsian, who should get a brief mention, is the Dane Peder Sørensen (1542–1602), better known as Petrus Severinus, who became chancellor of Denmark. In 1571 he published his Idea medicinae philosophicae (Ideal of Philosophical Medicine) (1571), which asserted the superiority of the ideas of Paracelsus to those of Galen and was highly influential, above all because it was written in Latin, the language of the learned rather than Paracelsus’ preferred German.


The German physician Daniel Sennert (1572–1637) author of De chymicorum cum Aristotelicis et Galenicis consensu ac dissensu (On the Agreements and Disagreements of the Chymists with the Aristotelians and Galenists) (1619), who became professor of medicine in Wittenberg, was highly influenced by Severinus, although he was one of those, who rejected Paracelsus the man. It was Sennert, who was most important in introducing the concept of atomism taken from the medieval alchemist Paul of Taranto (13th century) into the seventeenth century scientific debate exercising a major influence on Robert Boyle (1527–1691).

Source:Wikimedia Commons

Another important scholar influenced by Severinus was the Frenchman Guy de La Brosse (1586–1641) physician to King Louis XII and director of the first botanical garden in Paris Le Jardin du Roi founded in 1635. His support of Paracelsian medicine was particularly significant as the medical faculty of the university in Paris was vehemently anti-Paracelsus.

Le Jardin du Roi Paris

Perhaps Severinus’ most interesting follower was the astronomer, Tycho Brahe (1546–1601). It was Severinus, as Denmark’s most powerful politician, who persuaded the king to set up Tycho’s astronomical observatory on Hven, where Tycho also built a laboratory to produce Paracelsian medicines. 

To close a brief look at Paracelsus the physician beyond his chymiatria. Shut out by the medical establishment from the universities and the lucrative medical book market, Paracelsus must have been a successful physician, as he survived over the years on his reputation for healing wealthy private patients. In his polemics on the study of medicine, Paracelsus rejected book learning in favour of empirical observation and experience. He very much favoured hands on artisanal knowledge over, what he considered, the intellectual posturing of the university physicians. All of this places him very much in line with the general trends in Renaissance science, although he was certainly more radical than most of his contemporaries. His insistence on empirical observation is most notable in two areas where he made fairly novel contributions.

Paracelsus is credited with making one of the first studies of occupational diseases. His work in this direction is based on his observations of the typical diseases of the miners working in the areas where his father was employed and where he also worked from time to time. The second area where Paracelsus distinguished himself is in his analysis of mental illness. Although his writings on the subject are to a certain extent confused and complex, he does present some remarkable insights. He clearly distinguishes between genetic mental deficiency and mental illness. He diagnosed what we would now call manic-depression and was probably the first physician to recognise the existence of psychosomatic illnesses. Lastly, his suggested treatments for the mentally ill were positively humane compared to most of his contemporaries. All of this was very much based on clear-eyed empirical observation.

Theophrastus von Hohenheim is a very complex historical figure and it is almost impossible to do him justice in a brief blog post, but, however one views him, there is no denying that he had a major influence during the Renaissance both in the promotion of iatrochemistry and the turn away from book learning towards empirical investigation, perhaps the principle distinguishing feature of Renaissance science.

*Like many an oft quoted catch phrase, Sergeant Joe Friday never actually said “just the facts ma’am”. It only turns up in Stan Freburg’s brilliant Dragnet parody “St. George and the Dragonet” (1953), which is where I know it from, never actually having heard the original Dragnet.

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Filed under History of Chemistry, History of medicine, Renaissance Science

Renaissance Science – XXII

Perhaps surprisingly, land surveying as we know it today, a mathematical discipline utilising complex technological measuring instruments is very much a product of the practical mathematics of the Renaissance. Why surprisingly? Surveying is an ancient discipline that has its origins in humanity becoming settled many thousands of years ago. Ancient monuments such as the pyramids or Stonehenge definitely required some level of surveying in their construction and there are surviving documents from all literate ancient societies that refer to methods or the practice of surveying. 

All surveying uses some aspects of geometry and as Herodotus famously claimed geometry (Greek: geōmetría from geōmétrēs), which literally means measurement of earth or land, had its origins in Egyptian surveying for tax purposes. According to his account, King Sesostris divided all the lands in Egypt amongst its inhabitants in return for an annual rent. However, every year the Nile floods washing away the parts of the plots:

The country is converted into a sea, and nothing appears but the cities, which looked like islands in the Aegean. 

Those whose land had been lost objected to paying the rent, so Sesostris summoned those affected to appear before him.

Upon which, the king sent persons to examine, and determine by measurement the exact extent of the loss: and thenceforth only such a rent was demanded of him as was proportionate to the reduced size of his land. From this practice, I think, geometry first came to be known in Egypt, whence it passed into Greece.

According to legend, both Thales and Pythagoras, are reputed to have learnt their geometry in Egypt.

In all early cultures surveying was fairly primitive with measurements being made with ropes and measuring rods. In Egypt, surveyors were known as rope stretchers (harpedonaptai), the ropes used for measuring being stretched to avoid sagging.

A rope being used to measure fields. Taken from the Tomb of Menna, TT69. (c. 1500–1200 BCE) Source: Wikimedia Commons

Longer distances were either measured by estimation or by pacing. In ancient Egypt and Greece Bematistae (step measurer) where trained to walk with equal length paces and the historical records of Alexander the Great’s campaigns suggest that they were indeed highly accurate. This measuring of distances by pacing in reflected in our word mile, which is the Latin word for a thousand, mille, meaning a thousand paces.

The Latin for surveyor was agrimensores, meaning field measurers. They were also called gromatici after the groma a surveyor’s pole, an early instrument for determining lines at right angles to each other. 

The groma or gruma was a Roman surveying instrument. It comprised a vertical staff with horizontal cross-pieces mounted at right angles on a bracket. Each cross piece had a plumb line hanging vertically at each end. It was used to survey straight lines and right angles, thence squares or rectangles. They were stabilized on the high ground and pointed in the direction it was going to be used. The helper would step back 100 steps and place a pole. The surveyor would tell him where to move the pole and the helper would set it down.

(Lewis, M. J. T., Surveying instruments of Greece and Rome, McGraw Hill Professional, 2001, p. 120)
Staking out a right angle using a groma

Another instrument used for the same purpose was the dioptra. The dioptra was a sighting tube or, alternatively an alidade, that is a rod with a sight at each end, attached to a stand. If fitted with protractors, it could be used to measure angles. Hero from Alexandria wrote a whole book on this instrument and its use but there are doubts that the dioptra in the complex form described by Hero was actually used in field surveying.

Dioptra as described by Hero of Alexandria Source: Wikimedia Commons

The methods used by the Romans in field surveying were described in the works of technical authors such as Sextus Julius Frontinus (c. 40–103 CE) and Gaius Julius Hyginus (c. 64 BCE–17 CE).

All of the surveying described in antiquity was fairly small scale–measuring fields, determining boundaries, laying out military camps, etc–and geometrically centred on squares and rectangles. Cartography was done using astronomical determinations of latitude and longitude, whereby the latter was difficult, and distances estimated or paced. Nothing really changed in Europe during the medieval period. The surveying that was done was carried out using the same methods that the Romans had used. However, during the fifteenth century things began to change substantially and the first question is why?

The rediscovery of Ptolemaeus’ Geographia at the beginning of the fifteenth century, as described here, and the subsequent substantial increase in cartographical activity, as described here, played a major role, but as already stated above Ptolemaic cartography relied almost exclusively on astronomical methods and did not utilise field surveying. However, there was an increased demand for internal accuracy in maps that astronomical methods could not supply. Secondly, changes in land ownership led to an increased demand for accurate field surveying of estates that required more sophisticated methods than those of the agrimensores. Lastly, we have a good example of the knowledge crossover, typical for the Renaissance, as described in Episode V of this series. The surveyors of antiquity were artisans producing practical knowledge for everyday usage. In the Renaissance, university educated scholars began to interest themselves for this practical knowledge and make contributions to its development and it is these developments that we will now look at. 

The biggest change in surveying was the introduction of the simple geometrical figure the triangle into surveying, as Sebastian Münster, one of the most influential cosmographers (today we would say geographer) of the period, wrote in a German edition of his Cosmographia. Beschreibung aller Lender durch Sebastianum Münsterum in 1550:

Every thing you measure must be measured in triangles.

Actually, the theory of similar triangles, as explained in Euclid’s Elements, had been used in surveying in antiquity, in particular to determine the height of things or for example the width of a river. A method that I learnt as a teenager in the Boy Scouts.

What was new as we will see was the way that triangles were being used in surveying and that now it was the angles of the triangles that were measured and not the length of the sides, as in the similar triangles’ usage. We are heading towards the invention and usage of triangulation in surveying and cartography, a long-drawn-out process.

In his Ludi rerum mathematicarum (c. 1445), the architect Leon Battista Alberti describes a method of surveying by taking angular bearings of prominent points in the area he is surveying using a self-made circular protractor to create a network of triangles. He concludes by explaining that one only needs to the length of one side of one triangle to determine all the others. What we have here is an early description of a plane table surveying (see below) and step towards triangulation that, however, only existed in manuscript 

Alberti Ludi rerum mathematicarum 

Münster learnt his geometry from Johannes Stöffler (1452–1531), professor for mathematics in Tübingen, who published the earliest description of practical geometry for surveyors. In his De geometricis mensurationibus rerum (1513),

Johannes Stöffler Engraving from the workshop of Theodor de Brys, Source: Wikimedia Commons

Stöffler explained how inaccessible distances could be measured by measuring one side of a triangle using a measuring rod (pertica) and then observing the angles from either end of the measured stretch. However, most of the examples in his book are still based on the Euclidian concept of similar triangles rather than triangulation. In 1522, the printer publisher Joseph Köbel, who had published the Latin original, published a German version of Stöffler’s geometry book. 

Joseph Köbel Source: Wikimedia Commons

Both Peter Apian in his Cosmographia (1524) and Oronce Fine in his De geometria practica (1530) give examples of using triangles to measure distances in the same way as Stöffler.


Fine indicating that he knew of Stöffler’s book. Apian explicitly uses trigonometry to resolve his triangles rather than Euclidian geometry. Trigonometry had already been known in Europe in the Middle Ages but hadn’t been used before the sixteenth century in surveying. Fine, however, still predominantly used Euclidian methods in his work, although he also, to some extent, used trigonometry.

A very major development was the publication in 1533 of Libellus de locorum describendum ratione (Booklet concerning a way of describing places) by Gemma Frisius as an appendix to the third edition of Apian’s Cosmographia, which he edited, as he would all edition except the first. Here we have a full technical description of triangulation published for the first time. It would be included in all further editions in Latin, Spanish, French, Flemish, in what was the most popular and biggest selling manual on mapmaking and instrument making in the sixteenth and seventeenth centuries.

Source: Wikimedia Commons

1533 also saw the publication in Nürnberg by Johannes Petreius (c. 1497–1550) of Regiomontanus’s De triangulis omnimodis (On triangles of every kind) edited by the mapmaker and globe maker, Johannes Schöner (1477–1547).


This volume was originally written in 1464 but Regiomontanus died before he could print and publish it himself, although he had every intention of doing so. This was the first comprehensive work on trigonometry in Europe in the Early Modern Period, although it doesn’t cover the tangent, which Regiomontanus handled in his Tabula directionum (written 1467, published 1490), an immensely popular and oft republished work on astrology. 

Regiomontanus built on previous medieval works on trigonometry and the publication of his book introduces what Ivor Grattan Guinness has termed The Age of Trigonometry. In the sixteenth century it was followed by Rheticus’ separate publication of the trigonometrical section of Copernicus’s De revolutionibus, as De lateribus et angulis triangulorium in 1542. Rheticus (1514–1574) followed this in 1551 with his own Canon doctrinae triangulorum. This was the first work to cover all six trigonometric functions and the first to relate the function directly to triangles rather than circular arcs.

Source: Wikimedia Commons

Rheticus spent the rest of his life working on his monumental Opus Palatinum de Triangulis, which was, however, first published posthumously by his student Lucius Valentin Otho in 1596. Rheticus and Otho were pipped at the post by Bartholomaeus Pitiscus (1561–1613), whose Trigonometriasive de solutione triangulorum tractatus brevis et perspicuous was published in 1595 and gave the discipline its name.

Source: Wikimedia Commons

Pitiscus’ work went through several edition and he also edited and published improved and corrected editions of Rheticus’ trigonometry volumes. 

Through Gemma Frisius’ detailed description of triangulation and sixteenth century works on trigonometry, Renaissance surveyors and mapmakers now had the mathematical tools for a new approach to surveying. What they now needed were the mathematical instruments to measure distances and angles in the field and they were not slow in coming.

The measure a straight line of a given distance as a base line in triangulation surveyors still relied on the tools already used in antiquity the rope and the measuring rod. Ropes were less accurate because of elasticity and sagging if used for longer stretches. In the late sixteenth century, they began to be replaced by the surveyor’s chain, made of metal links but this also suffered from the problem of sagging due to its weight, so for accuracy wooden rods were preferred. 

A Gunter chain photographed at Campus Martius Museum. Source: Wikimedia Commons

In English the surveyor’s chain is usually referred to as Gunter’s chain after the English practical mathematician Edmund Gunter (1581–1626) and he is also often referred to erroneously as the inventor of the surveyor’s chain but there are references to the use of the surveyor’s chain in 1579, when Gunter was still a child. 

He did, however, produce what became a standardised English chain of 100 links, 66 feet or four poles, perches, or rods long, as John Ogilby (1600–1676) wrote in his Britannia Atlas in 1675:

…a Word or two of Dimensurators or Measuring Instruments, whereof the mosts usual has been the Chain, and the common length for English Measures 4 Poles, as answering indifferently to the Englishs Mile and Acre, 10 such Chains in length making a Furlong, and 10 single square Chains an Acre, so that a square Mile contains 640 square Acres…’

An English mile of 5280 feet was thus 80 chains in length and there are 10 chains to a furlong. An acre was 10 square chains. I actually learnt this antiquated system of measurement whilst still at primary school. The name perch is a corruption of the Roman name for the surveyor’s rod the pertica. 

To measure angles mapmakers and surveyors initially adopted the instruments developed and used by astronomers, the Jacob staff, the quadrant, and the astrolabe. An instrument rarely still used in astronomy but popular in surveying was the triquetum of Dreistab. The surveyors triquetum consists of three arms pivoted at two points with circular protractors added at the joints to measure angles and with a magnetic compass on the side to determine bearings. 

Surveyors then began to develop variants of the dioptra. The most notable of these, that is still in use today albeit highly modernised, was the theodolite, an instrument with sights capable of measuring angles both vertically and horizontally. The name first occurs in the surveying manual A geometric practice named Pantometria by Leonard Digges (c. 1515–c. 1559) published posthumously by his son Thomas (c. 1546–1595) in 1571.

Leonard Digges  A geometric practice named Pantometria Source

However, Digges’ instrument of this name could only measure horizontal angles. He described another instrument that could measure both vertical and horizontal angles that he called a topographicall instrument. Josua Habermehl, about whom nothing is known, but who was probably a relative of famous instrument maker Erasmus Habermehl (c. 1538–1606), produced the earliest known instrument similar to the modern theodolite, including a compass and tripod, in 1576. In 1725, Jonathan Sisson (1690–1747) constructed the first theodolite with a sighting telescope.

Theodolite 1590 Source:

A simpler alternative to the theodolite for measuring horizontal angles was the circumferentor. This was a large compass mounted on a plate with sights, with which angles were measured by taking their compass bearings.

18th century circumferentor

Instruments like the triquetum and the circumferentor were most often used in conjunction of another new invention, the plane table. Gemma Frisius had already warned in his Libellus de locorum describendum rationeof the difficulties of determining the lengths of the sides of the triangles in triangulation using trigonometry and had described a system very similar to the plane table in which the necessity for these calculation is eliminated. 

Surveying with plane table and surveyor’s chain

The plane table is a drawing board mounted on a tripod, with an alidade. Using a plumb bob, the table is centred on one end of a baseline, levelled by eye or after its invention (before 1661) with a spirit level, and orientated with a compass. The alidade is placed on the corresponding end of the scaled down baseline on the paper on the table and bearings are taken of various prominent features in the area, the sight lines being drawn directly on the paper. This procedure is repeated at the other end of the baseline creating triangles locating the prominent figures on the paper without having to calculate.

Philippe Danfrie (c.1532–1606) Surveying with a plane table

As with the theodolite there is no certain knowledge who invented the plane table. Some sources attribute the invention of the plane table to Johannes Praetorius (1537–1616), professor for mathematics at the University of Altdorf, as claimed by his student Daniel Schwentner (1585–1636). However, there was already a description of the plane table in “Usage et description de l’holomètre”, by Abel Foullon (c. 1514–1563) published in Paris in 1551. It is obvious from his description that Foullon hadn’t invented the plane table himself. 

The plane table is used for small surveys rather than mapmaking on a large scale and is not triangulation as described by Gemma Frisius. Although the Renaissance provided the wherewithal for full triangulation, it didn’t actually get used much for mapping before the eighteenth century. At the end of the sixteenth century Tycho Brahe carried out a triangulation of his island of Hven, but the results were never published. The most notable early use was by Willebrord Snel (1580–1626) to measure one degree of latitude in order to determine the size of the earth in 1615. He published the result in his Eratosthenes batavus in Leiden in 1617. He then extended his triangulation to cover much of the Netherlands.

Snel’s Triangulation of the Dutch Republic from 1615 Source: Wikimedia Commons

In the late seventeenth century Jean Picard (1620–1682) made a much longer meridian measurement in France using triangulation. 

Picard’s triangulation and his instruments

In fourteen hundred European surveyors were still using the same methods of surveying as the Romans a thousand years earlier but by the end of the seventeenth century when Jean-Dominique Cassini (1625–1712) began the mapping of France that would occupy four generations of the Cassini family for most of the eighteenth century, they did so with the fully developed trigonometry-based triangulation that had been developed over the intervening three hundred years. 


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

The amateur, astronomical, antiquarian aristocrat from Aix

In a recent blog post about the Minim friar, Marin Mersenne (1588–1648), I mentioned that when Mersenne arrived in Paris in 1619 he was introduced to the intellectual elite of the city by Nicolas-Claude Fabri de Peiresc (1580-1637). In another recent post on the Republic of Letters I also mentioned that Peiresc was probably, the periods most prolific correspondent, with more than ten thousand surviving letters. So, who was this champion letter writer and what role did he play in the European scientific community in the first third of the seventeenth century?

Nicolas-Claude Fabri de Peiresc by Louis Finson Source: Wikimedia Commons

Nicolas-Claude Fabri was born, into a family of lawyers and politicians, in the town Belgentier near Toulon on 1 December in 1580, where his parents had fled to from their hometown of Aix-en-Provence to escape the plagues. He was educated at Aix-en-Provence, Avignon, and the Jesuit College at Tournon. Having completed his schooling, he set off to Padua in Italy, nominally to study law, but he devoted the three years, 1600–1602, to a wide-ranging, encyclopaedic study of the history of the world and everything in it. 

In this he was aided in that he became a protégé of Gian Vincenzo Pinelli (1535–1601) a humanist scholar and book collector, his library numbered about 8,500 printed works, with all-embracing intellectual interests, whose main areas were botany, optics, and mathematical instruments.

Gian Vincènzo Pinelli Source: Rijksmuseum via Wikimedia Commons

Pinelli introduced Fabri to many leading scholars including Marcus Welser (1558–1614), Paolo Sarpi (1552–1623) and indirectly Joseph Scaliger (1540–1609). Pinelli also introduced him to another of his protégés, Galileo Galilei (1564–1642). One should always remember that although he was thirty-eight years old in 1602, Galileo was a virtually unknown professor of mathematics in Padua. When Pinelli died, Fabri was living in his house and became involved in sorting his papers.

In 1602, Fabri returned to Aix-en-Provence and completed his law degree, graduating in 1604. In the same year he assumed the name Peiresc, it came from a domain in the Alpes-de-Haute-Provence, which he had inherited from his father. He never actually visited Peiresc, now spelt Peyresq.

Village of Peyresq Source: Wikimedia Commons

Following graduation Peiresc travelled to the Netherlands and England via Paris, where he made the acquaintance of other notable scholars, including actually meeting Scaliger and also meeting the English antiquarian and historian William Camden (1551–1623).

Returning to Provence, in 1607, he took over his uncle’s position as conseiller to the Parliament of Provence under his patron Guillaume du Vair (1556–1621), cleric, lawyer, humanist scholar and president of the parliament.

Guillaume-du-Vair Source: Wikimedia Commons

In 1615 he returned to Paris with du Vair as his secretary, as du Vair was appointed keeper of the seals during the regency of Marie de’ Medici (1575–1642). Peiresc continued to make new contacts with leading figures from the world of scholarship, and the arts, including Peter Paul Rubens (1577–1640).

Peter Paul Rubens self-portrait 1623

Peiresc acted as a go between in the negotiations between Reubens and the French court in the commissioning of his Marie de’ Medici Cycle. Just one of Peiresc’s many acts of patronage in the fine arts.

Marie de’ Medici Cycle in the Richelieu wing of the Louvre Source: Wikimedia Commons

In 1621 de Vair died and in 1623 Peiresc returned to Provence, where he continued to serve in the parliament until his death in 1637.

Peiresc was an active scholar and patron over a wide range of intellectual activities, corresponding with a vast spectrum of Europe’s intellectual elite, but we are interested here in his activities as an astronomer. Having developed an interest for astronomical instruments during his time as Pinelli’s protégé, Peiresc’s astronomical activities were sparked by news of Galileo’s telescopic discoveries, which reached him before he got a chance to read the Sidereus Nuncius. He rectified this lack of direct knowledge by ordering a copy from Venice and borrowing one from a friend until his own copy arrived.

Source: Wikimedia Commons

He immediately began trying to construct a telescope to confirm or refute Galileo’s claims, in particular the discovery of the first four moons of Jupiter. At this point in his life Peiresc was still a geocentrist, later he became a convinced heliocentrist. We know very little about where and how he acquired his lenses, but we do know that he had various failures before he finally succeeded in observing the moons of Jupiter for himself, in November 1610. In this he was beaten to the punch by his fellow Provencal astronomer Joseph Gaultier de la Valette (1564–1647), vicar general of Aix. At this point it is not clear whether the two were competing or cooperating, as they would then later do with Gaultier de la Valette becoming a member of Peiresc’s Provencal astronomical observation group. Shortly thereafter, Peiresc became the first astronomer to make telescopic observations of the Orion Nebular and Gaultier de la Valette the second. This is rather strange as the Orion Nebular is visible to the naked eye. However, apparently none of the telescopic astronomy pioneers had turned their telescopes to it before Peiresc.

In one of the most detailed astronomical images ever produced, NASA/ESA’s Hubble Space Telescope captured an unprecedented look at the Orion Nebula. … This extensive study took 105 Hubble orbits to complete. All imaging instruments aboard the telescope were used simultaneously to study Orion. Source: Wikimedia Commons

Peiresc, like Galileo, realised that the moons of Jupiter could be used as a clock to determine longitude and began an observation programme of the moons, viewing them every single day that the weather conditions permitted, well into 1612. Having compiled tables of his observations he sent one of his own protégés Jean Lombard, about whom little is known, equipped with suitable instruments on a tour of the Mediterranean. Lombard observed the satellites at Marseille in November 1611 and then proceeded to Malta, Cyprus and to Tripoli observing as he went, until May 1612. Meanwhile, Peiresc made parallel observation in Aix and Paris, he hoped by comparing the time differences in the two sets of observations to be able to accurately determine the longitude differences. Unfortunately, the observations proved to be not accurate enough for the purpose and the world would have to wait for Giovanni Domenico Cassini (1625–1712) to become the first to successfully utilise this method of determining longitude. Peiresc’s own observation were, however, the longest continuous series of observations of the Jupiter moons made in the seventeenth century and displayed a high level of accuracy even when compared with this of Galileo.

I mentioned, above, Peiresc’s Provencal astronomical observing group. Peiresc employed/sponsored young astronomers to help him with his observation programmes, supplying them with instruments and instructions on how to use them. This group included such notable, future astronomers, as Jean-Baptiste Morin (1583–1556),

Jean-Baptiste Morin Source: Wikimedia Commons

Ismaël Boulliau (1605–1694),

Ismaël Boulliau Source: Wikimedia Commons

and Pierre Gassendi (1592–1655). Peiresc’s patronage extended well beyond this. Gassendi had held the chair of philosophy at the University of Aix-en-Provence since 1617 but in 1623 the university was taken over by the Jesuits and Gassendi was replaced by a Jesuit and became unemployed.

Portrait of Pierre Gassendi by Louis-Édouard Rioult Source: Wikimedia Commons

From then until he again found regular employment in 1634, Peiresc provided him with a home base in his own house and financed his travels and research. Similarly, Peiresc, having introduced Mersenne to Parisian intellectual circles in 1619, continued to support him financially, Mersenne as a Minim friar had no income, supplying him with instruments and financing his publications. 

Marin Mersenne Source: Wikimedia Commons

Patronage played a central role in Peiresc’s next venture into astronomy and another attempt to solve the longitude problem. There has been much talk in recent decades about so-called citizen science, in which members of the public are invited to participate in widespread scientific activities. Annual counts of the birds in one’s garden is a simple example of this. Citizen science is mostly presented as a modern phenomenon, but there are examples from the nineteenth century. Peiresc had already launched a variation on citizen science in the seventeenth century.

In order to determine longitude Peiresc further developed a method that had been in use since antiquity. Two astronomers situated in different location would observe a lunar or solar eclipse and then by comparing their observations they could determine the local time difference between their observations and thus the longitude difference between the locations. By the seventeenth century predicting eclipses had become a fairly accurate science and Peiresc thought that if he could organise and coordinated a world spanning network of observers to accurately observe and record an eclipse, he could then calculate a world spanning network of longitude measurements. The idea was good in theory but failed in practice.

Most of Peiresc’s team of observers were amateurs–missionaries, diplomats, traders, travellers–whom he supplied with astronomical instruments and written instructions on how to use them, even paying travelling expenses, where necessary. Peiresc organised mass observations for lunar eclipses in 1628, 1634, and 1635 and a solar eclipse in 1633. Unfortunately, many of his observers proved to be incompetent and the results of their observations were too inaccurate to be usable. One positive result was that Peiresc was able to correct the value for the length of the Mediterranean. Before one is too hard on Peiresc’s amateur observers, one should remember that in the middle of the eighteenth century the world’s professional astronomical community basically failed in their attempt to use the transits of Venus to determine the astronomical unit, despite being equipped with much better instruments and telescopes.

Although, Peiresc’s various astronomical activities and their results were known throughout Europe by word of mouth through his various colleagues and his correspondence, he never published any of his work. Quite why, is not really known although there are speculations.

Peiresc was a high ranking and highly influential Catholic and he applied that influence in attempts to change the Church’s treatment of astronomers he saw as being persecuted. He interceded on behalf Tommaso Campanella (1568–1639), actively supporting him when he fled to France in 1634.

Tommaso Campanella portrait by Francesco Cozza Source: Wikimedia Commons

More famously he personally interceded with the Church on behalf of Galileo, without any great success.

Nicolas-Claude Fabri de Peiresc’s career is, like that of his friend Mersenne, a good illustration that the evolution of science is a product of widespread cooperation of a community of practitioners and not the result of the genial discoveries of a handful of big names, as it is unfortunately too often presented. Morin, Boulliau, Gassendi and Mersenne, who all made serious contributions to the evolution of science in the seventeenth century, did so with the encouragement, guidance, and very active support of Peiresc.


Filed under History of Astronomy, History of Navigation, History of science, Renaissance Science, The Paris Provencal Connection

Renaissance Science – XXI

One of the products of the Republic of Letters during the Humanist Renaissance was the beginning or the foundation of the modern European library. Naturally they didn’t invent libraries; the concept of the library goes back quite a long way into antiquity. To a great extent, libraries are a natural consequence of the invention of writing. When you have writing, then you have written documents. If you preserve those written documents then at some point you have a collection of written documents and when that collection becomes big enough, then you start to think about storage, sorting, classification, listing, cataloguing and you have created an archive or a library. I’m not going try and sort out the difference between an archive and a library and will from now on only use the term library, meaning a collection of books, without answering the question, what constitutes a book?

The oldest know libraries are the collections of clay tablets found in the temples of Sumer, some of which date back to the middle of the third millennium BCE. There were probably parallel developments in ancient Egypt but as papyrus doesn’t survive as well as clay tablets there is less surviving evidence for early Egyptian libraries. There is evidence of a library in the Sumerian city of Nippur around two thousand BCE and a library with a classification system in the Assyrian city of Nineveh around seven hundred BCE. The Library of Ashurbanipal in Nineveh contained more than thirty thousand clay tablets containing literary, religious, administrative, and scientific works. Other ancient cultures such as China and India also developed early libraries.

Library of Ashurbanipal Mesopotamia 1500-539 BC Gallery, British Museum, Source: Wikimedia Commons

The most well-known ancient library is the legendary Library of Alexandria, which is clouded in layers of myth. The library was part of the of the Mouseion, a large research institute, which was probably conceived by Ptolemy I Soter (c. 367–282 BCE) but first realised by his son Ptolemy II Philadelphus (309–246 BCE). Contrary to popular myth it was neither destroyed by Christian zealots nor by Muslim ones but suffered a steady decline over a number of centuries. For the full story read Tim O’Neill’s excellent blog post on the subject, which also deals with a number of the other myths. As Tim points out, Alexandria was by no means the only large library during this period, its biggest rival being the Library of Pergamum founded around the third century BCE. The Persian Empire is known to have had large libraries as did the Roman Empire.

Artistic rendering of the Library of Alexandria, based on some archaeological evidence Source: Wikimedia Commons

With the gradual decline of the Western Roman Empire, libraries disappeared out of Europe but continued to thrive in the Eastern Empire, the future Byzantium. The Islamic Empire became the major inheritor of the early written records of ancient Greece, Egypt, Persia, and Rome creating in turn their own libraries throughout their territories. These libraries became to source of the twelfth century translation movement, also known as the scientific renaissance, when those books first began to re-enter medieval Europe. 

During the Early Middle Ages, the only libraries still in existence in what had been the Western Roman Empire were those that existed in the Christian monasteries. Here we must once again dispose of two connected myths. The first more general one is the widespread myth that Christians deliberately destroyed pagan literature i.e., the texts of the Greeks and Romans. In fact, as Tim O’Neill points out in another excellent blog post, we have Christians to thank for those texts that did survive the general collapse of an urban civilisation. The second, closely related myth, spread by the “the Church is and always was anti-science brigade”, is that the Church deliberately abandoned Greek science because it was ant-Christian. Once again as Stephen McCluskey has documented in his excellent, Astronomies and Cultures in Early Medieval Europe, (CUP; 1998) it was the monasteries that keep the flame of the mathematical science burning during this period even if only on a low flame.

The manuscript collections of the medieval libraries were very small in comparison to the great Greek libraries such as Alexandria and Pergamum or the many public libraries of Rome, numbering in the best cases in the hundreds but often only in the tens. However, the guardians of these precious written documents did everything in their power to keep the books safe and in good condition and also endeavouring to acquire new manuscripts by copying those from other monastery libraries, often undertaking very arduous journeys to do so. 

Chained library in Hereford Cathedral Most of the books in the collection date to about 1100. Source: Wikimedia Commons

Things began to improve in the twelfth century with the scientific renaissance and the translation movement, which coincided with the founding of the European universities. The number of works available in manuscript increased substantially but they still had to be copied time and again to gradually spread throughout Europe. Like the monasteries the universities also began to collect books and to establish libraries but if we look at the figures for Cambridge University founded in 1209. The university library has its roots in the beginning of the fifteenth century, there would have been earlier individual college libraries earlier. The earliest surviving catalogue from c. 1424 list 122 volumes in the library. By 1473 a second catalogue lists 330 volumes. It is first in the sixteenth century that things really take off and the library begins to grow substantially. The equally famous Oxford University Bodleian Library was first founded in 1600 by the humanist scholar Thomas Bodley in 1600, replacing the earlier university library from 1444, which had been stripped and dissipated during the Reformation. 

Thomas Bodley Artist unknown Source: Wikimedia Commons 

We have of course now reached the Humanist Renaissance and it is here that the roots of the modern library were laid. The Humanist Renaissance was all about written texts. The humanists read texts, analysed the content of texts, annotated texts, translated texts, and applied philological analysis to texts to correct and/or eliminate errors introduced into texts by repeated copying and translations. The text was everything for the humanists, so they began to accumulate collections of manuscripts. Both humanist scholars and the various potentates, who sponsored the humanist movement began to create libraries, as new spaces of learning. 

The Malatestiana Library was founded by Malatesta Novello of Cesena (1418–1485) in 1454.

Malatestiana Library of Cesena, the first European civic library Source: Wikimedia Commons

The foundations of the Laurentian Library in Florence were laid by Cosimo de’ Medici (1389–1464), as one of a sequence of libraries that he funded.

Reading room of the Laurentian Library Source: Wikimedia Commons

Pope Nicholas V (1397–1455) brought the papal Greek and Latin collections together in separate libraries in Rome and they were then housed by Pope Sixtus IV (1414–1484), who appointed the humanist Bartolomeo Platina (1421–1481) librarian of the Bibliotheca Apostolica Vaticana.

Sixtus IV appointing Bartolomeo Platina librarian of the Bibliotheca Apostolica Vaticana. From left Giovanni della Rovere, Girolamo Riario, Bartolomeo Platina, later Julius II (Giuliano della Rovere), Raffaele Riario, Pope Sixtus IV Source: Wikimedia Commons

This was followed by the establishment of many private libraries both in Rome and in other Italian cities. As with other aspects of the Humanist Renaissance this movement spread outside of Italy to other European Countries. For example, the Bibliotheca Palatina was founded by Elector Ludwig III (1378–1436) in Heidelberg in the 1430s.

Elector Ludwig III. Contemporary image on the choir ceiling of the  Stiftskirche (Neustadt an der Weinstraße). Source: Wikimedia Commons

These new humanist libraries were not just book depositories but as stated above new spaces for learning. The groups of humanist scholars would meet regularly in the new libraries to discuss, debate or dispute over new texts, new translations, or new philological corrections to old, corrupted manuscripts. 

The (re)invention of movable type printing in about 1450 meant that libraries began to collect printed books as well as manuscripts. The first printer publishers in Italy concentrated on publishing the newly translated texts of the humanists even creating a new type face, Antiqua, which imitated the handwriting that had been developed and propagated by the first generations of humanist scholars. 

The spread of libraries during the Renaissance is a vast subject, too much to deal with in a blog post, but one can get a perspective on this development by looking at a sketch of the career of Johannes Müller (1436–1476) aka Regiomontanus or as he was known during his live time, Johannes de Monte Regio. 

Smithsonian “Print Artist: Braeht” (whereby the signature appears to be rather Brühl sculps[it] possibly Johann Benjamin Brühl (1691-1763) ) – Smithsonian Institution Libraries Digital Collection Source: Wikimedia Commons

Regiomontanus is, today, best known as the most significant European mathematician, astronomer, and astrologer of the fifteenth century, so it comes as something of a surprise to discover that he spent a substantial part of his life working as a librarian for various humanist book collectors. 

Regiomontanus graduated MA at the University of Vienna on his twenty-first birthday in 1457. He had actually completed the degree requirements much earlier, but university regulations required MA graduates to be at least twenty-one years old. He then joined his teacher Georg von Peuerbach as a teacher at the university, lecturing on optics amongst other things. Both Regiomontanus and Peuerbach were convinced humanists. In 1460 Basilios Bessarion (1403–1472) came to Vienna.

Basilios Bessarion Justus van Gent and Pedro Berruguete Source: Wikimedia Commons

He was a Greek Orthodox monk, who had converted to Catholicism, been elevated to Cardinal and was in Vienna as papal legate to negotiate with the Holy Roman Emperor Frederick III on behalf of Pope Pius II. Pius II, civil Aeneas Silvius Piccolomini (1405–1464), was a humanist scholar well acquainted with Frederick and Vienna from his own time as a papal legate. Bessarion, a Neo-Platonist, was a very active humanist, setting up and sponsoring humanist circles wherever his travels took him. In Vienna he sought out Peuerbach to persuade him to undertake a new Latin translation of Ptolemaeus’ Mathēmatikē Syntaxis from the original Greek. Peuerbach couldn’t read Greek but he, and after his death Regiomontanus, produced their Epitome of the Almagest, the story of which I have told elsewhere. Bessarion asked Peuerbach to return to Italy with him. Peuerbach agreed on the condition that Regiomontanus could also accompany them. Peuerbach died in 1461, so only Regiomontanus accompanied Bessarion back to Italy and it is here that his career as librarian began.

Bessarion was an avid book collector and Regiomontanus’ job in his personal entourage was to seek out and make copies of new manuscripts for Bessarion’s collection. A task that he fulfilled with esprit. Bessarion had in the meantime also taught him Greek. In 1468, Bessarion presented his personal library to the Senate of Venice in 1468 and the 482 Greek manuscripts and 264 Latin manuscripts today still form the core of the St. Mark’s Biblioteca Marciana.

Cardinal Bessarion’s letter to Doge Cristoforo Moro and the Senate of Venice, announcing the donation of his library. BNM Lat. XIV, 14 (= 4235), fol. 1r. Source: Wikimedia Commons

Regiomontanus left Bessarion’s entourage around 1465 and reappears in 1467 at the court of János Vitéz Archbishop of Esztergom (German, Gran) in Hungary. 

János Vitéz frontispiece of a manuscript Source: Wikimedia Commons

Vitéz, an old friend of Peuerbach, was a humanist scholar and an avid book collector. Although Regiomontanus served as court astrologer, his Tabulae Directionum, one of the most important Renaissance astrological texts was produced at Vitéz’s request, his main function at Vitéz’s court was as court librarian. From Esztergom he moved to the court of the Hungarian King, Matthias Corvinus (1443–1490), who had been educated by Vitéz.

Matthias Corvinus of Hungary portrait by Andrea Mantegna Source: Wikimedia Commons

Like his teacher, Corvinus was a humanist scholar and a major book collector. Once more, Regiomontanus served as a court librarian. The Bibliotheca Corviniana had become one of the largest libraries in Europe, second only to the Bibliotheca Apostolica Vaticana, when Corvinus died. Unfortunately, following his death, his library was dissipated. 

Long before Corvinus’ death, Regiomontanus had left Hungary for Nürnberg, with Corvinus’ blessing and a royal pension, to set up a programme to reform astronomy in order to improve astrological divination. During his travels, Regiomontanus had not only made copies of manuscripts for his patrons, but also for himself, so he arrived in Nürnberg with a large collection of manuscript in 1471. His aim was to set up a printing house and publish philologically corrected editions of a long list of Greek and Latin mathematical, astronomical, and astrological texts, which he advertised in a publisher’s list that he printed and published. Unfortunately, he died in 1476 having only published nine texts including his publishers list and to the shame of the city council of Nürnberg, his large manuscript collection was not housed in a library but dissipated. 

To close a last example of a lost and dissipated Renaissance library. The English mathematicus John Dee (1527–1609) hoped to establish a national library, but he failed to get the sponsorship he wished for.

John Dee artist unknown Source: Wikimedia Commons

Instead, he collected books and manuscripts in his own house in Mortlake, acquiring the largest library in England and one of the largest in Europe. In the humanist tradition, this became a research centre, with other scholars coming to Mortlake to consult the books and to discuss their research with Dee and other visitors. However, when Dee left England for the continent, in the 1580s with Edward Kelly, to try and find sponsors for his occult activities, his house was broken into, and his library pillaged and sold off. 

Despite the loss of some of the largest Renaissance book collections and libraries, the period saw the establishment of the library both public and private, as a centre for collecting books and a space for learning from them. 

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Renaissance Science – XX

The term the Republic of Letters is one that one can often encounter in the history of Early Modern or Modern Europe, but what does it mean and to whom does it apply? Republic comes from the Latin res publica and means res “affair, matter, thing” publica “public, people.” However, here it is the “people” or “men”, as they mostly were, of letters. So, our Republic of Letters is the affairs of the men of letters or literati, as they are today more often known. Most often the Republic of Letters is used, as for example on Wikipedia, to refer to the long-distance intellectual community in the late 17th and 18th centuries in Europe and the Americas. However, the earliest known appearance of the term in Latin, respublica literaria, appeared in a letter from the Italian politician, diplomat, and humanist Francesco Barbaro (1390–1454)

Chiesa di Santa Maria del Giglio Venezia – Francesco Barbaro Source: Wikimedia Commons

written to his fellow country man the scholar and humanist Poggio Bracciollini (1380–1459)

Riproduzione novecentesca del ritratto di Poggio Bracciolini, inciso da Antonio Luciani nel 1715. Source: Wikimedia Commons

in 1417, so the original Republic of Letters was the Renaissance literary humanist movement of Northern Italy. Here, we also have a second interpretation of the Letters part of the term, meaning literally the letters that the members of the community wrote to each other to communicate their ideas, to announce their discoveries and to comment on the ideas and discoveries of others. In fact, that first use of the term came about when Poggio was off searching through monastery libraries and sent news of one of his discoveries back to Florence. Barbaro replied to his news thanking him for the gift offered to the literaria res publica for the greater progress of humanity and culture.

Initially this community of communication by letter was restricted to the comparatively small group of the literary humanists of Northern Italy, but with time came to embrace an ever-widening community from China to the Americas and including, as we will see, the whole world of science. Such a community didn’t exist in the Middle Ages, so what changed in the Renaissance that made this happen or indeed possible? 

One simple, partial answer was the change of available writing material, when paper replaced parchment and velum. Parchment and velum were much too expensive to be used for large scale letter writing and correspondence. As I sit at my desk writing this post I’m surrounded by an abundance of paper, piles of books printed on paper, delivery notes, invoices and bank statements printed on paper, notebooks and note slips made of paper, a printer/scanner/copier filled with paper waiting to be printed and other bits and bobs made of paper. Paper is ubiquitous in our lives, and we seldom think about its history. 

If we ignore the fact that wasps were making paper millions of years before humans emerged on the Earth, then paper has only existed for about 0.1% (approximately two thousand years) of the approximately two million years that the genus Homo has been around. It has only been present in Europe for about half of that time. Invented in China sometime before the second century BCE,

Woodcuts depicting the five seminal steps in ancient Chinese papermaking. From the 1637 Tiangong Kaiwu of the Ming dynasty. Source: Wikimedia Commons

paper making was transmitted into the Islamic Empire sometime in the eighth century CE. It first appeared in Europe in Spain in the eleventh century CE. This is of course during the High Middle Ages but the knowledge and use of paper remained restricted to Spain, Italy, and Southern France until well into the fourteenth century, when paper making began to slowly spread into Northern France, The Netherlands, and Germany. The first English paper mill wasn’t built until 1588. 

Ulman Stromer’s Paper-mill. First permanent paper-mill north of the Alps 1390 (From Schedel’s Buch der Chroniken of 1493.)

New production technics and new raw materials for paper production vastly increased output and reduced costs, so that by the fifteenth century paper was much more widely available and by many factors cheaper than parchment and a growing letter writing culture could and did develop. However, before that culture could truly develop, another aspect that we take for granted had to be developed, a delivery system. 

Once again, as I sit in front of my computer, I can communicate almost instantly with people all over the world by email or at least a dozen different social media channels. I can also grab my mobile telephone and either telephone with it or send an SMS. Or I can phone them with my landline telephone and if I want to send something tangible, I can resort to the post service or anyone of a dozen international delivery companies. We live in a thoroughly network society. Most of this simply didn’t exist forty years ago but even then, the landline telephones and the postal services connected people worldwide if at much higher costs. Of course, none of this existed in the Middle Ages.

In the High Middle Ages only the rulers and the Church had courier services to deliver their missives, others were dependent on the infrequent long distant traders and travellers. This began to change in the late Middle Ages/Renaissance as long distant trade began to become more and more frequent and the large North Italian and Southern German finance house became established. Traders and financiers built up communications networks throughout Europe, which also functioned as commercial post services. Big trading centres such as Nürnberg, Venice, and the North German Hansa cities had their own major, highly efficient courier services.

Late in the fourteenth century the Dutchy of Milan set up a postal service and in the second half of the fifteenth century Louis XI set up a post service in France. In 1490 the Holy Roman Emperor Maximilian I gave the von Taxis family a licence to set up a postal service for the whole of the empire. This is claimed to be the start of the modern postal series.

Taxis postal routes 1563 Source: Wikimedia Commons

By fifteen hundred it was possible for scholars throughout Europe to communicate with each other by letter and they did so in increasing numbers, setting up their own informal networks of those interested in a given academic discipline: Natural historians communicated with natural historians, mathematici with mathematici, humanist with humanists and not least artists with artists.

Augsburg Postoffice 1600 Source: Wikimedia Commons

With the advent of the of the so-called age of discovery the whole thing took on a new dimension with missionaries and scholars exchanging information with their colleagues at home in Europe from the Americas, Africa, India, China, and other Asian lands. Here it was the big international trading companies such as the Dutch East India Company and English East India Company, who served as the courier service.

A modern replica of the VOC Duyfken a small ship built in the Dutch Republic. She was a fast, lightly armed ship probably intended for shallow water, small valuable cargoes, bringing messages, sending provisions, or privateering. Source: Wikimedia Commons

There is another important aspect to this rising exchange of letters between scholars and that is the open letter meant for sharing. This was an age when the academic journal still didn’t exist, so if a scholar wished to announce a new discovery, theory, speculation, or whatever he could only do so by word of mouth or by letter if what he wished to covey was not far enough developed or extensive enough for a book or even a booklet. A scholar would write his thoughts in a long letter to another scholar in his field. If the recipient thought that the contained news was interesting or important enough, he would copy it and send it on to another scholar in the field or even sometimes several others. 

Through this process ideas gradually spread through a chain of letters within an informal network, throughout Europe.  By the seventeenth century several significant figures became living post offices each at the centre of a network of correspondence in their respective field. I recently wrote about Marin Mersenne (1588–1648), the Minim friar, who served such a function and who left behind about six hundred such letters from seventy-nine different scientific correspondence in his cell when he died.

Marin Mersenne Source: Wikimedia Commons

His younger contemporary the Jesuit professor of mathematics at the Collegio Romano, Athanasius Kircher (1602–1680), sat at the centre of a world spanning network of some seven hundred and sixty correspondents, collecting information from Jesuit missionaries throughout the world and redirecting it to other, not just Jesuit, scholars throughout Europe.

Athanasius Kircher portrait by Cornelis Bloemaert Source: Wikimedia Commons

One of his European correspondents, for example, was Leibniz (1646–1716), who himself maintained a network of about four hundred correspondents. 

Leibniz portrait by Christoph Bernhard Francke Source: Wikimedia Commons

Two members of Mersenne network, who had extensive correspondence networks of their own were Ismaël Boulliau (1605–1694), of whose correspondence, about five thousand letters written by correspondents from all over Europe and the Near East still exist although many of his letters are known to have been lost

Ismaël Boulliau portrait by Pieter van Schuppen Source: Wikimedia Commons

and Nicolas-Claude Fabri de Peiresc (1580–1637), who certainly holds the record with ten thousand surviving letters covering a wide range of scientific, philosophical, and artistic topics.

Nicolas-Claude Fabri de Peiresc portrait by Louis Finson Source: Wikimedia Commons

Later in the century the European mathematical community was served by the very active English mathematics groupie John Collins (1626–1683), collecting and distributing mathematics news. His activities would contribute to the calculus priority dispute and accusations of plagiarism between Newton and Leibniz, he, having supposedly shown Newton’s unpublished work to Leibniz. Another active in England at the same time as Collins was the German, Henry Oldenburg (c. 1618–1677), who maintained a vast network of correspondents throughout Europe.

Henry Oldenburg portrait by Jan van Cleve (III)

Oldenburg became Secretary of the newly founded Royal Society and used his letters to found the society’s journal, one of the first scientific journals, the Philosophical Transactions, the early issues consisting of collections of the letters he had received. Oldenburg’s large number of foreign correspondents attracted the attention of the authorities, and he was for a time arrested and held prisoner in the Tower of London on suspicion of being a spy.

The simple letter, written on comparatively cheap paper and delivered by increasingly reliable private and state postal services, made it possible for scholars throughout Europe to communicate and cooperate with each other, starting in the Early Modern period, in a way and on a level that had not been possible for their medieval predecessors. In future episodes of this series, we will look at how these correspondence networks helped to further the development of various fields of study during the Renaissance. 

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Renaissance Science – XIX

The publication of Vesalius’ De fabrica certainly marks a major change in the study and teaching of anatomy at the medieval university, but, as I hope is clear, that change did not come out of thin air but was the result of a couple of centuries of gradual developments in the discipline. It also didn’t trigger an instant revolution in the discipline throughout the university system but spread slowly, as is almost always the case with major innovations in a branch of knowledge. In the case of Vesalius’ anatomy, it was not just the normal inertia inherent in theory change, but also a long-prolonged opposition by neo-Galenists. 

The beginnings of the acceptance of Vesalius anatomy took place, naturally, in his own university of Padua and other North Italian universities resulting in a dynasty of excellent professors at those universities, leading to a major influx of eager students from all over Europe. 

Following Vesalius, the first of the significant Paduan anatomists was Gabriele Falloppio (1523–1562). Born in Modena, the son of an impoverished noble family. Lacking money, he joined the clergy, was appointed a canon of Modena Cathedral, and received an education in medicine at the University of Ferrara, graduating in 1548. In the same year he was appointed professor for anatomy at the university. In 1549 he was appointed professor for anatomy at the University of Pisa and in 1551 he received the same position at the University of Padua. Although, most well know today for his study of the reproductive organs leading to the naming of the Fallopian tubes after him, he made major contributions to our knowledge of bones and muscles. His major area of research was, however, the anatomy of the head where he systematically expanded our knowledge.

Portrait of Gabriele Falloppio artist unknown Source: Wikimedia Commons

Earlier that Falloppio was Matteo Realdo Colombo (c. 1515 – 1559), who was a colleague of Vesalius at Padua. The son of apothecary born in Cremona he initially apprenticed to his father but then became apprentice to the surgeon Giovanni Antonio Lonigo for seven years. In 1538 he enrolled as a medical student at Padua, where he quickly acquired a reputation for the study of anatomy. He became friends with Vesalius and was appointed to teach his courses while Vesalius was in Basel overseeing the publication of De fabrica. Vesalius attributes many of the discoveries in De fabrica to Colombo. Their relationship declined, when Colombo pointed out errors in Vesalius’ work, leading to them becoming rivals. 

Matteo Realdo Colombo artist unknown Source: Wikimedia Commons

Colombo left Padua in 1544 and went to the University of Pisa and from 1548 he worked at the papal university teaching anatomy until his death in 1459. Colombo was also involved in priority disputes with Falloppio. His only published text, De re anotomica issued posthumously in 1559 contains many discoveries also claimed by Falloppio, most notably the discovery of the clitoris and its sexual function.

Source: Wikimedia Commons

Colombo made many contributions to the study of anatomy, perhaps his most important discovery was the rediscovery of the so-called pulmonary circulation, previously discovered by Ibn al-Nafis (1213–1288) and Michael Servetus (c. 1511–1553).

Bartolomeo Eustachi (c. 1510–1574), a contemporary of Vesalius, who belonged to the competition, was a dedicated supporter of Galen working at the Sapienza University of Rome. 

Bartolomeo Eustachi artist unknown Source: Wikimedia Commons

 However, he made many important anatomical discoveries. He collated his work in his Tabulae anatomicae in 1552, but unfortunately this work was first published in 1714. 

Bartolomaeus Eustachius, Tabulae Anatomicae. Credit: Wellcome Library, London.

Julius Caesar Aranzi (1529/30–1589) was born in Bologna and studied surgery under his uncle Bartolomeo Maggi (1477–1552), who lectured on surgery at the University of Bologna.

Portrait of Julius Caesar Arantius (Giulio Cesare Aranzi, 1530–1589). From the Collection Biblioteca Comunale dell’Archiginnasio, Bologna, Italy. Source.

He studied medicine at Padua, where he made his first anatomical discovery at the age of nineteen in 1548. He finished his studies at the University of Bologna graduating in 1556. At the age of twenty-seven he was appointed lecturer for surgery at the university. Like the others he made numerous small contributions to our understanding of human anatomy, of particular importance was his study of foetuses. However, his major contribution was in the status of anatomy as a discipline. As professor for anatomy and surgery in Bologna starting in 1556, he established anatomy as a major discipline in its own right. 

A very central figure in the elevation of anatomy as a discipline at the medieval university was Girolamo Fabrici d’Acquapendente (1533–1619). Fabrici studied medicine in Padua under Falloppio graduating in 1559. He went into private practice in Padua and was very successful, numbering many rich and powerful figures amongst his patients. From 1562 till 1565 he also lectured at the university on anatomy. In 1565 he succeeded Falloppi as professor for anatomy and surgery at the university, a post he retained until 1613. As an anatomist he is considered one of the founders of modern embryology and as also renowned for discovering the valves that prevent blood following backwards in the veins, an important step towards the correct description of blood circulation.

Girolamo Fabrizi d’Acquapendente artist unknown Source: Wikimedia Commons

Girolamo Fabrici is also renowned for several of the students, who studied under him in Padua. Giulio Cesare Casseri (1552 – 8 March 1616) not only studied under Fabrici but was also employed as his servant.

Giulio Cesare Casseri artist unknown Source: Wikimedia Commons

The two of them later had a major falling out, but Casseri still succeeded Fabrici as professor in Padua. His biggest contribution was his Tabulae anatomicae, containing 97 copperplate engravings, published posthumously in in Venice 1627, which became one of the most important anatomical texts in the seventeenth century. 

Casseri was succeeded as professor in Padua by another of Fabrici’s students the Netherlander, Adriaan van den Spiegel (1578–1625).

Adriaan van den Spiegel artist unknown Source: Wikimedia Commons

Van den Spiegel was born in Brussels but studied initially in Leuven and Leiden, in 1601 he transferred to Padua, where he graduated in 1604. His main text, his De humani corporis fabrica libri decem, which he saw as an updated version of Vesalius’ book of the same title, was also published in Venice in 1627.

Source: Wikimedia Commons

For English readers Girolamo Fabrici’s most well-known student was William Harvey (1578–1657). Born the eldest of nine children to the jurist Thomas Harvey and his wife Joan Halke.

William Harvey, after a painting by Cornelius Jansen Source: Wikimedia Commons

He was educated at King’s School Canterbury and matriculated at Gonville & Caius College Cambridge in 1593. He graduated BA in 1597 and then set off on travels through mainland Europe. He travelled through France and Germany and matriculated as a medical student at Padua in 1599. During his time in Padua, he developed a close relationship with Fabrici graduating in 1602. Upon graduation he returned to England and having obtained a medical degree from Cambridge University, he became a fellow of Gonville & Caius. The start of a very successful career. His major contribution was, of course, his Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus (An Anatomical Exercise on the Motion of the Heart and Blood in Living Beings), the first correct account of the blood circulation and the function of the heart published in Frankfurt in 1628.


He also published an important work on the development of chicken embryos in the egg, Exercitationes de generatione animalium (On Animal Generation) published in 1651.

L0010265 W. Harvey, Exercitationes de generatione animalium Credit: Wellcome Library, London.

It could be argued that Girolamo Fabrici’s most important contribution to the history of anatomy was the erection of the university’s anatomical theatre. We saw in the last episode that the universities had been erecting temporary wooden dissecting spaces in winter for a couple of centuries, as described by Alessandro Benedetti (1450?–1512) in his Anatomicesivede historia corporis humani libri quique (AnatomyorFive Books on the History of the Human Body) in 1502:

A temporary theatre should be built at a large and well-ventilated place, with seats arranged in a circle, as in the Colosseum in Rome and the Area in Verona, sufficiently large to accommodate a great number of spectators in such a manner that the teacher would not be inconvenienced by the crowd… The corpse has to be put on a table in the centre of the theatre in an elevated and clear place easily accessible to the dissector. 

During the second half of the sixteenth century several institutions began to assign a permanent room for such spaces, the University of Montpellier in 1556, the Company of Barber Surgeons in London in 1557 and so on. Girolamo Fabrici raised the stakes by having the first ever purpose-built anatomical theatre designed and built in Padua in 1594. The project was the work of the Venetian polymath Paolo Sarpi (1552–1623) and the artist-architect Dario Varotari (c. 1539–1596). A closed elliptical shape with tiers of standing spaces for the observers rising steeply up the sides, giving a clear view of the dissecting table in the centre. 

Anatomical Theatre Padua design Source: Wikimedia Commons
Anatomical Theatre Padua as it is today Source: Wikimedia Commons

In Northern Italy the first to follow suit was the University of Bologna, which one year later opened its Anatomical Theatre of the Archiginnasio now situated in the Archiginnasio Palace the main building of the university.

A general view of the Anatomical theatre reconstructed after WWI when it was destroyed by bombing. Source: Wikimedia Commons

Originally situated elsewhere, it was rebuilt in its current setting between 1636 and 1638. The Bolognese rejected the Paduan Ellipse for a rectangular room claiming it to be superior.

Of greatest interest however was the Theatrum Anatomicum built far away from Northern Italy in 1596 in the still young university of Leiden. The University of Leiden was established in 1575, in the early phases of the Eighty Years’ War, as the first university of the newly founded United Provinces.

The Academy building of Leiden University in 1614. Source: Wikimedia Commons

Leuven, the original alma mater of Vesalius, was located in the remaining Spanish Netherlands. Home to both Rudolph Snel (1546–1613) and his son Willebrord (1580–1626) as well as Simon Stevin (1548–1629), who founded its school of engineering, the university was strong on the sciences for its early days. However, it was its school of medicine that would become most influential in the seventeenth century, and this school of medicine had deep connections to Padua and Girolamo Fabrici. 

The connections start with Johannes Heurnius (Jan van Heurne) (1543–1601), born in Utrecht, he initially studied in Leuven and Paris before going to Padua to study under Fabrici, where he graduated MD in 1566. Returning to the Netherlands he became a town physician in Utrecht before being appointed professor of medicine at the new University of Leiden in 1581. He introduced anatomy in the tradition of Vesalius into the still young Dutch university, as well as the Paduan emphasis on anatomical demonstrations and practical clinical work. 

Source: Wikimedia Commons

The anatomical theatre was introduced by Pieter Pauw (1564–1617), born in Amsterdam the son of the politician Pieter Pauw and his wife Geertruide Spiegel, he studied medicine at the University of Leiden, under Johannes Heurnius and Gerard Bontius (c. 1537–1599), another Padua graduate, graduating in 1584.

Pieter Pauw Source: Wikimedia Commons

He continued his studies in Rostock graduating MD in 1587. From here, he moved to Padua to study under Fabrici. Forced by his father’s illness he returned to Leiden in 1589, he was appointed assistant to Bontius, taking over responsibility for the medical botany. In 1592 he was appointed professor for anatomy and in 1596 he erected the permanent anatomical theatre in the same year. 

Leiden anatomical theatre in 1610. Source: Wikimedia Commons

Otto Heurnius (otto van Heurne) (1577–1652) was the son of Johannes Heurnius and studied medicine under his father and Pieter Pauw in Leiden. He graduated MD in 1601 and was appointed assistant to his father, whom he succeeded a year later as professor, not without criticism. In 1617 he then succeeded Pieter Pauw as professor for anatomy.

Otto Heurnius Source: Wikimedia Commons

Otto’s most famous student was Franciscus Sylvius (Franz de le Boë) (1614–1672). Born into an affluent family in Hanau he studied medicine at the Protestant Academy of Sedan then from 1632 to 1634 in Leiden, where he studied under Otto Heurius and Adolphus Vorstius (Adolphe Vorst) (1597–1663), who had also studied at Padua under Adriaan van den Spiegel, graduating MD in 1622. Vorstius was appointed an assistant in Leiden in 1624 and full professor in 1625. Sylvius continued his studies in Jena and Wittenberg, graduating MD in Basel in 1637. He initial practice medicine in Hanau but returned to Leiden to lecture in 1639. From 1641 he had a successful private practice in Amsterdam. In 1658 he was appointed professor for medicine at Leiden, with twice the normal salary. 

Franciscus Sylvius and his wife by Frans van Mieris, Sr. Source: Wikimedia Commons

Under Sylvius it became obvious, what had been true for some time, that Leiden had, in the place of Padua, become the leading European medical school, particularly in terms of anatomy. By the middle of the seventeenth century the change that Vesalius had introduced into the study and teaching of anatomy at the medieval university had been completed. Previously a minor aspect of the medical education, anatomy had now become a prominent and central discipline in that course of studies. Sylvius produced a stream of first-class graduates, who would go on to dominate the life sciences in the next decades that included Reinier de Graaf (1641–1673), who made important contributions to the understanding of reproduction,

Reinier de Graaf Source: Wikimedia Commons

Jan Swammerdam (1637–1680), an early microscopist, who made important studies of insects, 

Jan Swammerdam Reproductive organs of the bee drawn with a microscope Credit: Wellcome Library, London. There is no known portrait of Swammerdam

Nicolas Steno (1638–1686), who made important contribution to anatomy and geology,

Portrait of Nicolas Steno (1666–1677). Unsigned but attributed to court painter Justus Sustermans. (Uffizi Gallery, Florence, Italy) Source: Wikimedia Commons

and  Frederik Ruysch (1638–1731), an anatomist best know for his techniques for conserving anatomical specimens. 

The Anatomy Lesson of Dr. Frederick Ruysch by Jan van Neck (1683). Amsterdam Museum. Source: Wikimedia Commons

Sylvius was also one of those, who introduced chemistry into the study of medicine, which we will look at in the next episode.

For a detailed study of the work on reproduction of Harvey and many of the Leiden anatomist, I recommend Matthew Cobb’s The Egg & Sperm Race: The Seventeenth-Century Scientists Who Unravelled the Secrets of Sex, Life and Growth, The Free Press, London, 2006


Filed under Book History, History of medicine, History of science, Renaissance Science