An important 13th-century book on optics

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

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

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

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

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

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

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

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

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

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

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

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

Book VI: in convex spherical mirrors

Book VII: in convex cylindrical and conical mirrors

Book VIII: in concave spherical mirrors

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

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

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

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

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

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

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

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

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

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

Source: Wikimedia Commons

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

Apian’s Instrumentum Title Page Source: Sothebys

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

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

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

Copernicus De revolutionibus title page Source: Wikimedia Commons

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

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

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

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

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

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

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

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

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

You can read Part I here

Before we progress we need to take stock and deal with a couple of points that came up in a comment to Part I. This series is about the factors that led to the emergence of heliocentricity in Europe in the Early Modern Period. It doesn’t deal with any of the factors from earlier periods and other cultures that also explicitly and implicitly flowed into European astronomy. If one were to include all of those, it would be a total history of western astronomy that doesn’t even start in the West but in Babylon in about 2000 BCE. That is not what I intend to write and I won’t be doing so.

The other appears to contradict what I said above. At my starting point circa 1400 CE people became aware of a need to increase their usage of mathematical astronomy for a number of reasons that I sketched in Part I. Ptolemaic mathematical astronomy had been available in Europe in two Latin translations, the first from Greek the second from Arabic, since the twelfth century. However, medieval Europeans in general lacked the mathematical knowledge and to some extent the motivation to engage with this highly technical work. The much simpler available astronomical tables, mostly from Islamic sources, fulfilled their needs at that time. It was only really at the beginning of the fifteenth century that a need was seen to engage more fully with real mathematical astronomy. Having said that, at the beginning the users were not truly aware of the fact that the models and tables that they had inherited from the Greeks and from Islamic culture were inaccurate and in some cases defective. Initially they continued to use this material in their own endeavours, only gradually becoming aware of its deficiencies and the need to reform. As in all phases of the history of science these changes do not take place overnight but usually take decades and sometimes even centuries. Science is essential conservative and has a strong tendency to resist change, preferring to stick to tradition. In our case it would take about 150 years from the translation of Ptolemaeus’ Geographiainto Latin, my starting point, and the start of a full-scale reform programme for astronomy. Although, as we will see, such a programme was launched much earlier but collapsed following the early death of its initiator.

Going into some detail on points from the first post. I listed Peuerbach’s Theoricarum novarum planetarum(New Planetary Theory), published by Regiomontanus in Nürnberg in 1472, as an important development in astronomy in the fifteenth century, which it was. For centuries it was thought that this was a totally original work from Peuerbach, however, the Arabic manuscript of a cosmology from Ptolemaeus was discovered in the 1960s and it became clear that Peuerbach had merely modernised Ptolemaeus’ work for which he must have had a manuscript that then went missing. Many of the improvements in Peuerbach’s and Regiomontanus’ epitome of Ptolemaeus’ Almagest also came from the work of Islamic astronomers, which they mostly credit. Another work from the 1^st Viennese School was Regiomontanus’ De Triangulis omnimodis Libri Quinque (On Triangles), written in 1464 but first edited by Johannes Schöner and published by Johannes Petreius in Nürnberg in1533.

Title page of a later edition of Regiomontanus’ On Triangle

This was the first comprehensive textbook on trigonometry, the mathematics of astronomy, published in Europe. However, the Persian scholar Abū al-Wafā Būzhjānī (940–988) had already published a similar work in Arabic in the tenth century, which of course raises the question to what extent Regiomontanus borrowed from or plagiarised Abū al-Wafā.

These are just three examples but they should clearly illustrate that in the fifteenth and even in the early sixteenth centuries European astronomers still lagged well behind their Greek and Islamic predecessors and needed to play catch up and they needed to catch up with those predecessors before they could supersede them.

After ten years of travelling through Italy and Hungary, Regiomontanus moved from Budapest to Nürnberg in order to undertake a major reform of astronomy.

City of Nürnberg Nuremberg Chronicles Workshop of Michael Wohlgemut Printed by Aton Koberger and published in Nürnberg in 1493

He argued that astrological prognostications were inaccurate because the astronomical data on which they were based was also inaccurate, which it indeed was. He had an ambitious two part programme; firstly to print and publish critical editions of the astronomical and astrological literature, the manuscripts of which he had collected on his travels, and secondly to undertake a new substantial programme of accurate astronomical observations. He tells us that he had chosen Nürnberg because it made the best scientific instruments and because as a major trading centre it had an extensive communications network. The latter was necessary because he was aware that he could not complete this ambitious programme alone but would need to cooperate with other astronomers.

Arriving in Nürnberg, he began to cooperate with a resident trading agent, Bernhard Walther, the two of them setting up the world’s first printing press for scientific literature. The first publication was Peuerbach’s Theoricae novae planetarum (New Planetary Theory)

followed by an ambitious catalogue of planned future publications from the astrological and astronomical literature. Unfortunately they only managed another seven publications before Regiomontanus was summoned to Rome by the Pope to work on a calendar reform in 1475, a journey from which he never returned dying under unknown circumstances, sometime in 1476. The planned observation programme never really got of the ground although Walther continued making observations, a few of which were eventually used by Copernicus in his De revolutionibus.

Regiomontanus did succeed in printing and publishing his Ephemerides in 1474, a set of planetary tables, which clearly exceeded in accuracy all previous planetary tables that had been available and went on to become a scientific bestseller.

However he didn’t succeed in printing and publishing the Epytoma in almagesti Ptolemei; this task was left to another important early publisher of scientific texts, Erhard Ratdolt (1447–1528, who completed the task in Venice twenty years after Regiomontanus’ death. Ratdolt also published Regiomontanus’ astrological calendars an important source for medical astrology.

Calendarius by Regiomontanus, printed by Erhard Ratdolt, Venice 1478, title page with printers’ names Source: Wikimedia Commons

The first printed edition of Ptolemaeus’ Geographia with maps was published in Bologna in 1477; it was followed by several other editions in the fifteenth century including the first one north of the Alps in Ulm in 1482.

The above is a reproduction woodcut of Ptolemy’s (90-168 CE) map of the world by Johane Schnitzer (Ulm: Leinhart Holle, 1482). The original map was lost.

The re-invention of moveable type printing by Guttenberg in about 1450 was already having a marked effect on the revival and reform of mathematical astronomy in Early Modern Europe.

 

 

 

 

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

I have recently been involved in more that one exchange on the subject as to what tipped the scales in favour of heliocentricity against geocentricity in the Early Modern Period. People have a tendency to want to pin it down to one crucial discovery, observation or publication but in reality it was a very gradual process that took place over a period of at least three hundred and fifty years and involved a very large number of people. In what follows I intend to sketch that process listing some, but probably not all, of the people involved. My list might appear to include people, who at first might not appear to have contributed to the emergence of modern astronomy if one just considers heliocentricity. However, all of those who raised the profile of astronomy and emphasised its utility in the Early Modern Period raised the demand for better and more accurate astronomical data and improved models to produce it. The inclusion of all these factors doesn’t produce some sort of linear progress but more a complex mosaic of many elements some small, some simple, some large and some spectacular but it is not just the spectacular elements that tells the story but a sum of all the elements. So I have cast my nets very wide.

The first question that occurs is where to start. One could go back all the way to Aristarchus of Samos (c.310–c.230 BCE) but although he and his heliocentric theories were revived in the Early Modern Period, it was largely with hindsight and he played no real role in the emergence of heliocentricity in that time. However, we should definitely give a nod to Martianus Capella (fl.c. 410–420), whose cosmos model with Mercury and Venus orbiting the Sun in an otherwise geocentric model was very widespread and very popular in the Middle Ages and who was quoted positively by Copernicus.

The Capellan system Source: Manuscript Florenz, Biblioteca Medicea Laurenziana, San Marco 190, fol. 102r (11th century) via Wikimedia Commons

Another nod goes to Jean Buridan (c.1300–c.1358/61), Nicole Oresme (c.1320-1325–1382), Pierre d’Ailly (1351–1420) and Nicholas of Cusa (1401–1464) all of whom were well-known medieval scholars, who discussed the model of geocentrism with diurnal rotation, a model that was an important step towards the acceptance of heliocentricity.

I start with a figure, who most would probably not have on the radar in this context, Jacopo d’Angelo (c.1360–1411). He produced the first Latin translation of Ptolemaeus’ Geōgraphikḕ Hyphḗgēsis(Geographiaor Cosmographia) in Florence in 1406.

Manuscript: d’Angelo’s translation of Ptolemy’s Geography Source: Scan from Nancy Library (Hosted at Wikicommons, early 15th century).

This introduced a new concept of cartography into Europe based on a longitude and latitude grid, the determination of which requires accurate astronomical data. Mathematical, astronomy based cartography was one of the major forces driving the reform or renewal of astronomy in the Early Modern Period. Another major force was astrology, in particular astro-medicine or as it was known iatromathematics, which was in this period the mainstream school medicine in Europe. Several of the astronomy reformers, most notably Regiomontanus and Tycho, explicitly stated that a reform of astronomy was necessary in order to improve astrological prognostications. A third major driving force was navigation. The Early Modern Period includes the so call great age of discovery, which like mathematical cartography was astronomy based. Slightly more nebulous and indirect were new forms of warfare, another driving force for better cartography as well as the collapse of the feudal system leading to new forms of land owner ship, which required better surveying methods, also mathematical, astronomy based. As I pointed out in an earlier post the people working in these diverse fields were very often one and the same person the Renaissance mathematicus, who was an astrologer, astronomer, cartographer, surveyor or even physician.

Our next significant figure is Paolo dal Pozzo Toscanelli (1397–1482), like Jacopo d’Angelo from Florence, a physician, astrologer, astronomer, mathematician and cosmographer.

Paolo dal Pozzo Toscanelli. Detail taken from the 19th century honorary monument to Columbus, Vespucci and Toscanelli dal Pozzo in the Basilica di Santa Croce in Florence (Italy). Source: Wikimedia Commons

Most famous for his so-called Columbus world map, which confirmed Columbus’ erroneous theory of the size of the globe. In our context Toscanelli is more important for his observation of comets. He was the first astronomer in the Early Modern Period to treat comets as astronomical, supralunar objects and try to record and measure their trajectories. This was contrary to the ruling opinion of the time inherited from Aristotle that comets were sublunar, meteorological phenomena. Toscanelli did not publish his observations but he was an active member of a circle of mathematically inclined scholars that included Nicholas of Cusa, Giovanni Bianchini (1410 – c.1469), Leone Battista Alberti (1404 – 1472),Fillipo Brunelleschi (1377 – 1446) and most importantly a young Georg Peuerbach (1423–1461) with whom he probably discussed his ideas.

Here it is perhaps important to note that the mathematical practitioners in the Early Modern Period did not live and work in isolation but were extensively networked, often far beyond regional or national boundaries. They communicated extensively with each other, sometimes in person, but most often by letter. They read each other’s works, both published and unpublished, quoted and plagiarised each other. The spread of mathematical knowledge in this period was widespread and often surprisingly rapid.

We now turn from Northern Italy to Vienna and its university. Founded in 1365, in 1384 it came under the influence of Heinrich von Langenstein (1325–1397), a leading scholar expelled from the Sorbonne in Paris, who introduced the study of astronomy to the university, not necessarily normal at the time.

Probably Heinrich von Langenstein (1325-1397), Book illumination im Rationale divinorum officiorum des Wilhelmus Durandus, circa 1395 Source: Archiv der Universität Wien, Bildarchiv Signatur: 106.I.1840 1395

Heinrich was followed by Johannes von Gmunden (c.1380–1442) who firmly established the study of astronomy and is regarded as the founder of the 1^stViennese School of Mathematics.

Johannes von Gmunden Calendar Nürnberg 1496 Source: Wikimedia Commons

Georg Peuerbach the next member of the school continued the tradition of astronomical studies established by Heinrich and Gmunden together with his most famous student Johannes Regiomontanus.

Johannes Regiomontanus Source: Wikimedia Commons

It can’t be a coincidence that Peuerbach and Regiomontanus extended Toscanneli’s work on comets, with Regiomontanus even writing a pamphlet on the determination of parallax of a moving comet, which was only publish posthumously in the sixteenth century. The two Viennese astronomers also designed and constructed improved astronomical instruments, modernised the trigonometry necessary for astronomical calculations and most importantly with Peuerbach’s Theoricarum novarum planetarum(New Planetary Theory),

Georg von Peuerbach, Theoricae novae planetarum, Edition Paris 1515 Source: Wikimedia Commons

first published by Regiomontanus in Nürnberg in 1472, and their joint Epytoma in almagesti Ptolemei, a modernised, shortened improved edition of Ptolemaeus’ Syntaxis Mathematiké

Epytoma in almagesti Ptolemei: Source

first published by Ratdolt in Venice in 1496, produced the standard astronomy textbooks for the period right up into the seventeenth century.

The work on the Viennese School very much laid the foundations for the evolution of the modern astronomy and was one of the processes anchoring the ‘modern’ study of astronomy an the European universities, How the journey continues will be told in Part II of this series.

 

 

 

 

 

 

 

 

 

Christmas Trilogy 2018 Part 3: Johannes’ battle with Mars

It would be entirely plausible to claim the Johannes Kepler’s Astronomia Nova was more important to the eventual acceptance of a heliocentric view of the cosmos than either Copernicus’ De revolutionibus or Galileo’s Sidereus Nuncius. As with most things in Kepler’s life the story of the genesis of the Astronomia Nova ΑΙΤΙΟΛΟΓΗΤΟΣ seu physica coelestis, tradita commentariis de motibus stellae Martis ex observationibus G.V. Tychonis Brahe, to give it its full title, is anything but simple.

Astronomia Nova title page Source: Wikimedia Commons

From his studies at Tübingen University Kepler was sent, in 1594, by the Lutheran Church to Graz as mathematics teacher in the local Lutheran school and as district mathematicus, responsible for surveying, cartography and above all yearly astrological prognostica. His situation in Graz, a predominantly Catholic area, was anything but easy and as the Counter Reformation gained pace the Lutheran school was closed and the Protestants were given the choice of converting to Catholicism or leaving the area. Largely because of the success of his prognostica Kepler was granted an exemption. However, by 1600 things got very tight even for him and he was desperately seeking a way out. All of his efforts to obtain employment failed, including, somewhat surprisingly, an appeal to his teacher Michael Mästlin in Tübingen.

During his time in Graz he had published his first book, Mysterium Cosmographicum (The Cosmographic Mystery), in which he attempted to prove, the for us today bizarre hypothesis, that in a heliocentric cosmos there were and could only be six planets because their obits were separated by the ratios of the volumes of the five regular Platonic solids. He realized that regular polygons bound one inscribed and one circumscribed circle at definite ratios, which, he reasoned, might be the geometrical basis of the universe. However, when he actually did the maths he realised that although he had a good approximation, it wasn’t good enough; he blamed the failing accuracy on the poor quality of the data he had available. He needed to obtain better data.

Kepler’s Platonic solid model of the solar system, from Mysterium Cosmographicum (1596) Source: Wikimedia Commons

Kepler was well aware of the fact that, for the last thirty years or so, Tycho Brahe had been accumulating vast quantities of new, comparatively accurate data, so he decided to go visit the Danish aristocratic astronomer in Prague, maybe there was also a chance of employment. There was, however, a small problem with this plan. As a young, first time author, he had sent complimentary copies of his publication to all of the leading European astronomers. This had led to the first correspondence with Galileo, who had received his copy rather more by accident than by design but also to a very tricky situation with Tycho. Kepler had sent a copy to Nicolaus Reimers Baer (1551–1600), also called Ursus, at the time Tycho’s predecessor as Imperial Mathematicus to the Emperor Rudolph II; this was accompanied by the usual highly flattering Renaissance letter of introduction. Ursus was engaged in a very bitter priority dispute with Tycho about the so-called Tychonic system, Tycho had accused him of having stolen it during a visit to Hven, and Ursus printed Kepler’s flattering letter in a highly insulting answer to Tycho’s accusations. Kepler was very definitely not Tycho’s favourite astronomer, as a result. Despite all of this Tycho, also in desperate need of new assistants since moving to Prague, actually invited the young Kepler to come and visit him. By a strange twist of fate the letter of invitation arrived after Kepler had already left Graz for Prague.

Kepler duly arrived in Prague and one of the most fateful meetings in the history of astronomy took place. That first meeting was a monumental disaster. Kepler took umbrage and departed to sulk in a Prague hotel, convinced that his journey to Prague had been in vain. However, thanks to the diplomatic efforts of the Bohemian physician Johannes Jessenius (1566–1621) the two hot heads settled their differences and Tycho offered Kepler at least temporary employment. Having no better offers Kepler agreed, returned to Graz, packed up his home and together with his wife and children returned to Prague.

Unfortunately, there was no way that Tycho was going to trust a comparative stranger with the accumulated treasures of thirty years of observations and Kepler had to be satisfied with the tasks that Tycho gave him. First of all, maybe as a form of punishment, Tycho set him to work writing a vindication of Tycho’s claims against Ursus. Although Kepler did not produce the stinging condemnation of Ursus that Tycho wanted, he did produce a fascinating philosophical analysis of the role of hypothesis in the history of astronomy, A Defence of Tycho against Ursus, which was not published at the time but which historian Nicholas has described in the title of his scholarly edition of the work as ‘the birth of history and philosophy of science.[1]’ On the astronomical front, Tycho gave Kepler what would prove to be a task of immeasurable importance in the history of astronomy, the determination of the orbit of Mars.

When Kepler initially arrived in Prague to work with Tycho, Longomontanus, Tycho’s chief assistant, was working on the orbit of Mars. With Kepler’s arrival Tycho moved Longomontanus onto his model of the Moon’s orbit and put Kepler onto Mars. When first assigned Kepler famously claimed that he would knock it off in a couple of weeks, in the end he took the best part of six years to complete the task. This fact out of Kepler’s life often gets reported, oft with the false claim that he took ten years, but what the people almost never add is that in those six years the Astronomia Novawas not the only thing that occupied his time.

Not long after Kepler began his work Tycho died and he inherited the position of Imperial Mathematicus. This, however, had a major snag. Tycho’s data, the reason Kepler had come to Prague, was Tycho’s private property and that inherited his children including his daughter Elizabeth and her husband Frans Gansneb genaamd Tengnagel van de Camp. Being present when Tycho had died, Kepler secured the data for himself but was aware that it didn’t belong to him. There followed long and weary negotiations between Kepler and Frans Tengnagel, who claimed that he intended to continue Tycho’s life’s work. However, Tengnagel was a diplomat and not an astronomer, so in the end a compromise was achieved. Kepler could retain the data and utilise it but any publications that resulted from it would have Tengnagel named as co-author! In the end he contributed a preface to the Astronomia Nova. Kepler also spent a lot of time and effort haggling with the bureaucrats at Rudolph’s court, attempting to get his salary paid. Rudolph was good at appointing people and promising a salary but less good at paying up.

Apart from being distracted by bureaucratic and legal issues during this period Kepler also produced some other rather important scientific work. In 1604 he published his Astronomiae Pars Optica, written in 1603, which was the most important work in optics published since the Middle Ages and laid the foundations for the modern science. It included the first explanations of how lenses work to correct short and long sight and above all the first-ever correct explanation of how the image is formed in the eye. The latter was confirmed empirically by Christoph Scheiner.

Astronomiae Pars Optica title page

In 1604 a supernova appeared in the skies and Kepler systematically observed it, confirmed it was definitively supralunar (i.e. above the moon’s orbit) and wrote up and published his findings, De Stella nova in pede Serpentarii, in Prague in 1606.

Stella nova in pede Serpentarii title page

The Astronomia Nova is almost unique amongst major scientific publications in that it appears to outline in detail the work Kepler undertook to arrive at his conclusions, including all of the false turnings he took, the mistaken hypotheses he used and then abandoned and the failures he made in his calculations. Normally scientific researchers leave these things in their notebooks, sketchpads and laboratory protocols; only presenting to their readers a sanitised version of their results and the calculations or experiments necessary to achieve them. Why did Kepler act differently with his Astronomia Nova going into great detail on his six-year battle with Mars? The answer is contained in my ‘it appears’ in the opening sentence of this paragraph. Kepler was to a large extent pulling the wool over his readers’ eyes.

Kepler was a convinced Copernicaner in a period where the majority of astronomers were either against heliocentricity, mostly with good scientific reasons, or at best sitting on the fence. Kepler was truly revolutionary in another sense, he believed firmly in a physical cause for the structure of the cosmos and the movement of the planets. This was something that he had already propagated in his Mysterium Cosmographicum and for which he had been strongly criticised by his teacher Mästlin. The vast majority of astronomers still believed they were creating mathematical models to save the phenomena, irrespective of the actually physical truth of those models. The true nature of the cosmos was a question to be answered by philosophers and not astronomers.

Kepler structured the rhetoric of the Astronomia Nova to make it appear that his conclusions were inevitable; he had apparently no other choice, the evidence led him inescapably to a heliocentric system with real physical cause. Of course, he couldn’t really prove this but he did his best to con his readers into thinking he could. He actually road tested his arguments for this literary tour de force in a long-year correspondence with the Frisian astronomer David Fabricius. Fabricius was a first class astronomer and a convinced Tychonic i.e. he accepted Tycho’s geo-heliocentric model of the cosmos. Over the period of their correspondence Kepler would present Fabricius with his arguments and Fabricius would criticise them to the best of his ability, which was excellent. In this way Kepler could slowly build up an impression of what he needed to do in order to convince people of his central arguments. This was the rhetoric that he then used to write the final version of Astronomia Nova[2].

To a large extent Kepler failed in both his main aims when the book was published in 1609. In fact it would not be an exaggeration to say that it was initially a flop. People weren’t buying either his heliocentricity or his physical cause arguments. But the book contains two gems that in the end would prove very decisive in the battle of the cosmological systems, his first and second laws of planetary motion:

1) That planets orbit the Sun on elliptical paths with the Sun situated at one focus of the ellipse

2) That a line connecting the planet to the Sun sweeps out equal areas in equal periods of time.

Kepler actually developed the second law first using it as his primary tool to determine the actually orbit of Mars. The formulation of this law went through an evolution, that he elucidates in the book, before it reached its final form. The first law was in fact the capstone of his entire endeavour. He had known for sometime that the orbit was oval and had even at one point considered an elliptical form but then rejected it. When he finally proved that the orbit was actually an ellipse he knew that his battle was over and he had won. Today school kids learn the first two laws together with the third one, discovered thirteen years later when Kepler was working on his opus magnum the Harmonice mundi, but they rarely learn of the years of toil that Kepler invested in their discovery during his battle with Mars.

[1]Nicholas Jardine, The Birth of History and Philosophy of Science: Kepler’s ‘A Defence of Tycho against Ursus’ with Essays on its Provenance and Significance, CUP, ppb. 2009

[2]For an excellent account of the writing of Astronomia Novaand in particular the Kepler-Fabricius correspondence read James R. Voelkel, The Composition of Kepler’s Astronomia Nova, Princeton University Press, 2001

Printing the Hindu-Arabic numbers

Arte dell’Abbaco, a book that many consider the first-ever printed mathematics book, was dated four hundred and forty years ago on 10 December 1478. I say many consider because the book, also known as the Treviso Arithmetic, is a commercial arithmetic textbook and some historians regard commercial arithmetic as a separate discipline and not really mathematics.

Calculation from the Arte dell’Abbaco

The unknown author explains his book thus:

I have often been asked by certain youths in whom I have much interest, and who look forward to mercantile pursuits, to put into writing the fundamental principles of arithmetic, commonly called abbacus.

The Treviso Arithmetic is actually an abbacus book, those books on calculating with the Hindu-Arabic numerals that derive their existence from Leonardo Pisano’s Liber Abbaci. Like most abbacus books it is written in the vernacular, which in this case is the local Venetian dialect. If you don’t read 15^thcentury Venetian there is an English translation by Frank J. Swetz, Capitalism and Arithmetic: The New Math of the 15^thCentury – Including the Full Text of the Treviso Arithmetic of 1478, Open Court, 1987.

Books about the book

Most readers are probably aware that I live not very far away from the Renaissance city of Nürnberg in Southern Germany. It is a city rich in the history of science particularly during the Renaissance and so it was only a mater of time, after I moved here, that I would get sucked into becoming a local historian. In the end it was the fact that Copernicus’ magnum opus was printed and published there that proved to be the bait. This, however, also took me down another path, the early history of scientific printing in which the city is particularly rich. Not only was it the home of Johannes Petreius, who printed and published the De revolutionibus, as well as many other important early scientific titles, but it was also where Johannes Müller, aka Regiomontanus, chose to set up the world’s first-ever scientific publishing house. Researching Regiomontanus as a printer publisher leads automatically to Erhard Ratdolt, who, whilst not a Nürnberger printer publisher, published several of those titles that Regiomontanus intended to publish but was unable to due to his untimely demise. Around 1500 CE, the world’s biggest printed publisher was the Nürnberger Anton Koberger, who printed, amongst many other volumes, the Liber Chronicarum. Better know as the Nuremberg Chronicle in English and Die Schedel’sche Weltchronik in German, the world’s first-ever printed encyclopaedia. As always when I develop an interest for a historical topic I try to view it not as isolated incidents but to develop knowledge of and a feeling for the complete historical context, as far as this is possible. This inevitably leads to the acquisition of books on the topic, preferably general, wide ranging, good quality reference books to which I can return as the situation demands. I now have a small, but I think, high-quality collection of books about the book. Last week saw a new addition to this collection Erik Kwakkel’s Books Before Print[1].

Having followed Erik on Twitter for a small eternity, at the same time reading his blog and also having had the pleasure of meeting him in person and hearing him lecture on the subject of the medieval book, I knew his book wouldn’t disappoint and it doesn’t. This is an introduction to the medieval book for people, who like me, have little or no knowledge of them. Basically a modified version of his blog on the subject it consists of short, clear simple chapters on each individual aspect of medieval manuscripts, divided into five sections: 1. Filling the Page: Script, Writing, and Page Design 2. Enhancing the Manuscript: Binding and Decoration 3. Reading in Context: Annotations, Bookmarks, and Libraries 4. The Margins of Manuscript Culture 5. Contextualizing the Medieval Manuscript.

Excellently structured, well written and beautifully illustrated this volume fulfils its intended purpose admirably; it really is everything you wanted to know about the medieval manuscript book and were too afraid to ask.

As I often get asked to recommend books on a given topic and so having started this post I decided to give a small overview of the books that I have and use on the history of the book. As a historian of science my main interest is in the invention of moving type printing, which according to conventional wisdom was one of the major driving forces of the so-called scientific revolution, thus most of the books I have deal primarily with the emergence of the printed book.

The Renaissance Mathematicus book-history-books bookshelf

However, the first book I would recommend is one for the general reader covering the entire history of the book from clay tablets to the modern printed book, Keith Houston’s The Book:A Cover-to-Cover Exploration of the Most Powerful Object of Our Time, which I reviewed here, so I won’t say anything more now. As a small bonus I also recommend Houston’s Shady Characters:The Secret Life of Punctuation, Symbol & Other Typographical Marks[2]. It’s eccentric, unique and a delight.

In his essay in TheCambridge Companion to the History of the Book(of which more later) Adrian Johns writes: “The introduction of Printing into western Europe has counted as the signature event of the history of the book ever since Lucien Febvre and Henri-Jean Martin’s l’Apparition du Livre launched the modern discipline in 1958. The purpose of l’Apparitionwas to demonstrate that Johann Gutenberg’ innovation was the most important turning point in human history, separating modernity from everything before”[3]The Febvre/Martin, The Coming of the Book[4]in English translation is a classic and was the book that introduced me to book history. Although now dated both in its historical facts and its historiography I still think it can be read with profit, although if wishing to quote anything from it one should check against more up to date works.

Next up is another absolute classic Elizabeth Eisenstein’s The printing press as an agent of change[5] probably the most famous and most influential volume on book history. Originally published in two volumes it is now available as a single volume paperback weighing in at just under 800 pages. Eisenstein introduced the concept of print culture, which she contrasts with the preceding age of the manuscript and to which she attributes massive influence (change) not only in the scientific revolution but also in the Reformation, claiming it as an unacknowledged revolution. It is a cornucopia of information, thoughts, ideas and theories that repays careful reading.

However Eisenstein’s central thesis does not go unchallenged. Our next book is Adrian Johns’ equally massive The Nature of the Book.[6] Johns’ sets out his stall thus, “The unifying concept of Eisenstein’s argument is that of “print culture.” This “culture” is characterized primarily in terms of certain traits that print is said to endow on texts. Specifically, those produced in such an environment are subject to conditions of standardization, dissemination, and fixity. The last of these is perhaps the most important.”[7] Johns’ then devotes his 700 plus pages to supposedly proving that Eisenstein’s “print culture” and above her fixity did not exist. Like Eisenstein’s tome it is also a cornucopia of information, thoughts, ideas and theories that repays careful reading. However, I personally don’t think he actually succeeds in proving his central thesis.

The American Historical Review staged a forum[8], introduced by Anthony Grafton, with a defence of her thesis by Eisenstein followed by a response from Johns and then a reply from Eisenstein in which the adversaries mostly argued past each other rather than with each other. However you can read both volumes and the forum and decide for yourself who is right! Happy reading.

If you wanted something shorter than the Eisenstein/Johns debate then you can turn to Andrew Pettegree’s The Book in the Renaissance.[9] Pettegree starts with the book before printing and follows with the invention of printing. He then introduces what he defines as the crisis in printing. This is the fact that there was not a large enough market for the Latin academic and theological texts that was the original fare of the earliest printing houses leading to an economic crisis. Out of this crisis emerged new forms of literature generated by the publishing houses to create new markets to finance their presses. This ‘creation of a European book market’, as he terms it is the central theme of Pettegree’s interesting and stimulating book.

Already mention above, The Cambridge Companion to the History of the Book (see footnote 3) is a collection of papers covering a wide-ranging series of book history topics from a very modern standpoint and is more than worth reading as a supplement to the volumes sketched above.

Another slightly dated but still useful volume is Colin Clair’s A History of European Printing.[10] This is basically an annotated chronology of the spread of the book printing business throughout Europe from its beginnings down to the end of the nineteenth century.

I close with a beautiful volume issued by the Gutenberg-Gesellschaft and Gutenberg-Museum, which is, unfortunately for those who don’t read the language, only available in German, Blockbücher des Mittelalters: Bilderfolgen als Lektüre.[11] Which is a collection of detailed essays on the books printed in Europe in the second half of the fifteenth century with woodblocks, issued as a guide to an exhibition of these books in the Gutenberg-Museum from 22 June to 1 September 1991. The book forms a complete history of this interesting anomaly in the European history of the printed book.

There has been, of course, since Levbre/Martin established the modern book history discipline with their tome in 1958 a vast flood of academic literature on the history of the book in Europe and indeed the world much of which the interested reader can find listed in the very extensive bibliographies of the volumes described above. As I also said above, happy reading!

 

 

[1]Erik Kwakkel, Books Before Print, ARC Humanities Press, Leeds, 2018

[2]Keith Houston, Shady Characters: The Secret Life of Punctuation, Symbol & Other Typographical Marks, W. W. Norton, New York & London, 2013.

[3]Adrian Johns, The coming of print to Europe, in The Cambridge Companion to the History of the Book, ed. Leslie Howsam, CUP, Cambridge, 2015

[4]Lucien Febvre and Henri-Jean Martin, The Coming of the Book, Verso, London & New York, ppb. 1997

[5]Elizabeth L. Eisenstein, The printing press as an agent of change: Communications and cultural transformations in early-modern Europe, CUP, Cambridge et al., ppb. 1980

[6]Adrian Johns, The Nature of the Book: Print and Knowledge in the Making, Chicago University Press, Chicago and London, ppb. 1998

[7]Johns, The Nature of the Book p. 10

[8]American Historical Review: Volume 107, Issue 1, 2002, pp. 84-128

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

[10]Colin Clair, A History of European Printing, Academic Press, London, New York, San Francisco, 1976

[11]Blockbücher des Mittelalters: Bilderfolgen als Lektüre, Herausgegeben von Gutenberg-Gesellschaft und Gutenberg-Museum, 1991.

Apples & Pears – comparing print technologies

 

On Facebook I recently stumbled across a link to a piece on 3 Quarks Daily, which in turn was only a lede for a short essay on the London Review of Books entitled, The Oldest Printed Book in the World. This is an article about the Chinese Dunhuang Diamond Sūtra

Frontispiece of the Chinese Diamond Sūtra, the oldest known dated printed book in the world. The colophon, at the inner end, reads: Reverently [caused to be] made for universal free distribution by Wang Jie on behalf of his two parents on the 13th of the 4th moon of the 9th year of Xiantong [i.e. 11th May, CE 868 ] Source: British Library via Wikimedia Commons

 from the ninth century explaining its origin and how it came to be housed in the British Library. The article contains the following sentence:

A colophon at the end of the Dunhuang Diamond Sūtra scroll dates it to 868, nearly six centuries before the first Gutenberg Bible.

Although not stated explicitly the intention of this sentence seems to be, the Chinese invented book printing six hundred years before the Europeans. Although on a very superficial level this is true it is actually a case of comparing apples with pears, as the two books in question are printed with very different reproduction technologies. The Dunhuang Diamond Sūtra is a woodblock print, whereas the Gutenberg Bible is printed with movable type.

First page of the first volume: The Epistle of St. Jerome from the University of Texas copy. Source: Ransom Center of the University of Texas at Austin via Wikimedia Commons

For woodblock printing the image to be printed is carved into a woodblock or rather the parts that are not to be printed are cut away with a knife or chisel. This is then inked and pressed onto the sheet of material, cloth or paper, to be printed. The used block produced by this difficult process can only be used to print this one page. With moveable type the individual pieces of type, or sorts, are composed into the image to be printed, inked and pressed into the sheet of material to be printed. When finished the sorts can be reused to compose a new page and so on. Once cut a set of woodblocks can only be used to print the same book over and over again. A full set of type can be continually reconfigured to print literally thousand of different books. This difference is important and the six hundred year gap throws up some very important and intriguing historical questions.

A case of cast metal type pieces and typeset matter in a composing stick Source: Wikimedia Commons

Central to these is the question of technological transfer. Woodblock printing was developed in East Asia sometime before the third century CE. The oldest fragments of printed cloth date to 220 CE. The oldest woodblock prints on paper date to the late seventh century CE. And as stated above to oldest extant woodblock printed book the Dunhuang Diamond Sūtra dates to 868 CE. Although the Chinese invention of paper arrived in Spain via the Islamic Empire in the late eleventh century CE and crossed the Alps into Northern Europe in the late fourteenth century CE, woodblock printing does not appear to have accompanied it. Strangely European books printed with woodblocks, block books, apparently only appeared after Gutenberg had introduced printing with movable type in the second half of the fifteenth century. There are a very limited number of such books mostly dating from the 1460s and 1470s and printed in the Netherlands of Southern Germany.

Block book – Biblia Pauperum (“Bible of the Poor”) Netherlands 1460s/70s Source: Wikimedia Commons

Gutenberg was by no means the first to use moveable type. Around 1040 CE a Chinese inventor, Bi Sheng (990–1051) invented a form of moveable type with the pieces of type made of ceramics. Beyond a short description of his invention nothing more is known about it and nothing he might have printed has survived. This was followed in East Asia by various other forms of moveable type carved from wood or made of various metals. The oldest book printed with wooden movable type was Records of Jingde County printed by Wang Zhen in 1298. In 1313 he published an account of his invention A method of making moveable wooden types for printing books.

A revolving typecase for wooden type in China, from Wang Zhen’s book published in 1313 Source: Wikimedia Commons

The oldest known book printed with metal moveable type is the two volume Jikji, a collection of excerpts from the analects of revered Buddhist monks, printed with metal type in Korea in 1377; that is at least seventy years before Gutenberg’s famous Bible. However, whereas 49 copies of Gutenberg’s Bible still exist, of which 21 are complete, only one copy of the second volume of the Jikji is still extant.

Korean movable type from 1377 used for the Jikji Source: Wikimedia Commons

Jikji or “Selected Teachings of Buddhist Sages and Seon Masters”, published in 1377, Korea during the Goryeo Dynasty. Source: Wikimedia Commons

Even within Europe Gutenberg was not the first to use moveable type, with several people experimenting with varying system. However Gutenberg was the first to produce anything functional and in reality his greatest inventions were not so much moveable type as the printing press (he converted a wine press) and printing ink or to put it another way he didn’t just invent moveable type but the whole printing process.

Replica of the Gutenberg press at the International Printing Museum in Carson, California Source: Wikimedia Commons

Although extensive effort has been invested into the research on the topic, no evidence has been found of a technology transfer from East Asia to Europe and it is thought that Gutenberg’s was an independent (re)invention.

Although my account is itself only a sketch of the development of printing, both woodblock and moveable type ( I don’t even touch upon book (re)production before woodblock printing or after moveable type), my main argument is that the London Review of Books article in just making its invalid comparison between the Dunhuang Diamond Sūtra and Gutenberg’s Bible creates an inadequate and distorted impression of a long and complex historical process; an impression that uninformed readers will take away with them. A mythical historical meme has been created “the first printed book is the Dunhuang Diamond Sūtra and not the Gutenberg Bible” to replace the Eurocentric myth that Gutenberg invented movable type printing and his Bible is the earliest printed book. If writing short popular historical pieces for the general public we should avoid simplistic descriptions and thereby the risk of creating myths rather than transmitting real knowledge.