Today in something is wrong on the Internet

When I was growing up one of the most widespread #histSTM myths, along with the claim that people in the Middle Ages believed the world was flat and Stone Age people lived in holes in the ground, was that Galileo Galilei invented the telescope. This myth actually has an interesting history that goes all the way back to the publication of the Sidereus Nuncius. Some of Galileo’s critics misinterpreting what he had written asserted that he was claiming to have invented the telescope, an assertion that Galileo strongly denied in a latter publication. Whatever, as I said when I was growing up it was common knowledge that Galileo had invented the telescope. During the 1960s and 1970s as history of science slowly crept out of its niche and became more public and more popular this myth was at some point put out of its misery and buried discretely, where, I thought, nobody would find it again. I was wrong.

When I wrote my essay on the origins of the reflecting telescope for the online journal AEON, my editor, Corey Powell, who is himself a first class science writer and an excellent editor, asked me to provide a list of reference books to help speed up the process of fact checking my essay. I was more than happy to oblige, as even more embarrassing than a fact checker finding a factual error in what I had written, and yes even I make mistakes, would be a reader finding a real clangour after my essay had been published. As it turned out I hadn’t made any mistakes or if I did nobody has noticed yet. Imagine my surprise when I read an essay published two days ago on AEON that stated Galileo had invented the telescope. Hadn’t it been fact checked? Or if so, didn’t the fact checker know that this was a myth?

The essay in question is titled Forging Islamic Science and was written by Nir Shafir and edited by Sally Davies. The offending claim was at the beginning of the second paragraph:

Besides the colours being a bit too vivid, and the brushstrokes a little too clean, what perturbed me were the telescopes. The telescope was known in the Middle East after Galileo invented it in the 17th century, but almost no illustrations or miniatures ever depicted such an object.

I tweeted the following to both the author’s and AEON’s Twitter accounts:

If the author is complaining about forgers getting historical details wrong he really shouldn’t write, “The telescope was known in the Middle East after Galileo invented it in the 17th century…”

The author obviously didn’t understand my criticism and tweeted back:

There are references to the use of telescopes for terrestrial observations, mainly military, in the Ottoman Empire, such as in evliya çelebi.

I replied:

Galileo did not invent the telescope! He wasn’t even the first astronomer to use one for astronomical observations!

Whereupon Sally Davies chimed in with the following:

Thank you for drawing this to our attention! A bit of ambiguity here; we have tweaked the wording to say he ‘developed’ the telescope.

Sorry but no ambiguity whatsoever, Galileo did not in anyway invent the telescope and as I will explain shortly ‘developed’ is just as bad.

Today the author re-entered the fray with the following:

Thank you for bringing this up. It’s always good to get the minor details right.

The invention of the telescope is one of the most significant moments in the whole history of science and technology, so attributing its invention to the completely false person is hardly a minor detail!

About that ‘developed’. A more recent myth, which has grown up around Galileo and his use of the telescope, is that he did something special in some sort of way to turn this relatively new invention into a scientific instrument usable for astronomical observations. He didn’t. The telescope that Galileo used to discover the Moons of Jupiter differed in no way either scientifically or technologically from the one that Hans Lipperhey demonstrated to the assembled prominence at the peace conference in Den Hague sometime between the 25thand 29thof September 1608. Lipperhey’s invention was even pointed at the night sky, “and even the stars which normally are not visible for us, because of the scanty proportion and feeble sight of our eyes, can be seen with this instrument.”[1]

Both instruments consisted of a tube with a biconvex or plano-convex objective lens at one end and a bi-concave or plano-concave eyepiece lens at the other end. The eyepiece lens also had a mask or stop to cut down the distortion caused around the edges of the lens. The only difference was in the focal lengths of the lenses used producing different magnitudes of magnification. Galileo’s use of other lenses to increase magnification was nothing special; it had been done earlier than Galileo by Thomas Harriot and at least contemporaneous if not earlier by Simon Marius. It was also done by numerous others, who constructed telescopes independently in those first few years of telescopic astronomical observation. The claims that Galileo had developed, improved, specialised, etc., etc., the telescope are merely mythological elements of the more general Galileo hagiography. Modern research has even revealed that contrary to his own claims Galileo probably did not (re)-construct the telescope purely from having heard reports about it but had almost certainly seen and handled one before he attempted to construct one himself.

Going back to the offending AEON essay, Sally Davies could have saved herself and Nir Sharfir if she had simply changed the sentence to:

The telescope was known in the Middle East after it was invented  in the late 16th early 17th century…(even I make mistakes)

What I intended to write before my brain threw a wobbly was:

The telescope was known in the Middle East after it was invented in late 1608…

 She doesn’t even need to mention Lipperhey’s name if she wants to avoid the on going debates about who really did invent the telescope.








[1]Embassies of the King of Siam Sent to His Excellency Prince Maurits, Arrived in The Hague on 10 September 1608



Filed under History of Astronomy, History of Optics, History of science, History of Technology, Myths of Science, Renaissance Science, Uncategorized

Saxton and Speed two early Elizabethan cartographers and the Flemish influence

It is possible to date the start of the gradual emergence of modern cartography to the first decade of the fifteenth century when Jacopo d’Angelo produced the first Latin translation of Ptolemaeus’ Geographia(Geōgraphikḕ Hyphḗgēsis); this important Greek work had not been translated in the great wave of scientific translations in the High Middle Ages. This new knowledge of Ptolemaeus’ cartography with its projections and its longitude and latitude grids first took hold in Northern Italy, where its most famous early exponent was physician and mathematicus Paolo dal Pozzo Toscanelli (1379–1482) author of the so-called Columbus map.


Paolo dal Pozzo Toscanelli Source: Wikimedia Commons

From Northern Italy the new cartographer spread fairly rapidly to Austria and by 1450 Vienna was a major centre for cartography. Not long after the invention of movable metal type printing editions of the Geographia began to appear, initially without maps but very soon with, and by 1500 various editions were making their way around Europe. From Vienna the knowledge of the new cartographer moved north into Germany, with two schools of cartography developing. The so-called historical school was centred on the St. Dié mapmakers in Lorraine and includes Sebastian Münster in Basel. Whereas the so-called mathematical school, also known as the Vienna-Nürnberg school, has Johannes Schöner and Peter Apian as its two most significant exponents. Both schools include both aspects of the Ptolemaic cartography, the historical and the mathematical, in their maps and the difference is rather more one of emphasis.

From Southern Germany the new cartography spread throughout Europe. Notable cartographers, for example, are Pedro Nunes in Portugal and Oronce Fine in France. However the major centre for the new cartography became the so-called Flemish school centred on Gemma Frisius at the University of Louvain. Its two most notable associates are Gerhard Mercator and Abraham Ortelius, the two most influential cartographers in the second half of the sixteenth century.

But what of England? As with the mathematical sciences in general, England lagged well behind the continent in terms of cartography. The first Britain to become acquainted with the new developments in cartography was probably John Dee, who following his graduation at Cambridge university travelled extensively on the continent and spent two years in Louvain studying and working together with both Gemma Frisius and Gerard Mercator.


John Dee artist unknown Source: Wikimedia Commons

During his travels he also formed close friendships with both Abraham Ortelius and Pedro Nunes. When he returned to Britain Dee brought the latest developments in the Ptolemaic cartography, Frisius’ new methods of surveying through triangulation and the latest astronomical, cartographical and surveying instruments with him from Louvain. The Flemish/Dutch influence is clearly visible in the early English atlases.

It is probably no coincidence that the two ministers at Elizabeth’s court in London who pushed hard for the introduction of the new cartography into England were Sir Francis Walsingham, principle secretary to Elizabeth, and William Cecil, 1stBaron Burghley, Elizabeth’s chief advisor, both of whom were Dee’s, somewhat unreliable, patrons at court.


Engraving of Queen Elizabeth I, William Cecil and Sir Francis Walsingham, by William Faithorne, 1655 Source: Wikimedia Commons

Their motivations for supporting the development of cartography were political and derived from military and commercial considerations and not academic or scientific ones. The same applies, of course to the general developments in cartography in the Early Modern Period throughout Europe. Burghley, the main driving force behind a new English cartography, possessed a self made atlas of manuscript maps from various sources that he is said to have always carried with him. Burghley’s atlas has survived and is now in the British Library.


William Cecil, 1st Baron Burghley from NPG artist unkown Source: Wikimedia Commons

Burghley saw the necessity, on political grounds, of organising and financing a new, modern map of the British Isles. The first cartographer, who appears to have received a commission to map Britain from Burghley, was John Rudd (c. 1498–1597). In 1561 Rudd, a graduate of Clare College and a fellow of St. John’s Cambridge, was granted a two-year paid leave of absence from his various positions in the Church of England in order to travel the country with the objective of mapping England. It is not know if Rudd fulfilled his objective, as no map of England can with certainty be assigned to him. However, it has been speculated that his work was a source for the new map of Britain published by Mercator in his atlas. Several of the maps in Burghley’s handmade atlas are attributed to Rudd.


This is a manuscript map of County Durham. It forms part of an atlas that belonged to William Cecil Lord Burghley, Elizabeth I’s Secretary of State. Burghley used this atlas to illustrate domestic matters. The map dates from 1569 and is by John Rudd, the man to whom Christopher Saxton was an apprentice to in 1570. Source: British Library

In his work Rudd employed Christopher Saxon (c. 1540–c.1610) as an assistant and taught him the art of surveying. Born in the West Riding of Yorkshire in 1542 or 1544 very little is known about Saxton’s childhood, although his employment by Rudd is confirmed by documents. On Burghley’s instructions Thomas Seckford, Master in Ordinary of the Court of Request at Elizabeth’s Court,


Thomas Seckford Source: East Anglian Times

commissioned Christopher Saxton in 1573 to survey all the English counties and produce an atlas of the realm. It is not certain what motivated Burghley to act at this time but it might have been the publication of Ortelius’ Theatrum orbis terrarumin 1570, which was much admired in England, and/or Philipp Apian’s Bairischen Landtafeln from 1566

The survey of England began in 1574 and of Wales in 1577; it was completed in 1578. The individual maps were engraved as soon as finished and the proofs sent to Burghley.

Saxton1 map England Royal MS 18 D lll no 5

Saxton England and Wales proof map Source: British Library

In 1579 the maps were bound together and publish as a book for which Saxton received ten-year exclusive publication rights from the crown.


Frontispiece Saxton The Counties of England and Wales Source: My facsimile copy

Although we now refer to Saxton’s book as an atlas at the time Mercator’s coining of the term still lay sixteen years in the future. It is not known how Saxton did his surveying work but the speed with which he completed the task and the general level of accuracy of his maps would suggest two things. Firstly that he had access to previous data, possibly from Rudd’s work amongst others, and secondly that he used triangulation in some form. The nationwide chain of beacons set up by the government to warn of a Spanish invasion from the Netherlands in 1567 would have provided him with a useful set of predetermined triangulation points. The pass issued by the Privey Council on 10 July 1576 for his survey of Wales also strongly suggests triangulation as his survey method.

An open Lettre to all Justices of peace mayours & others etc within the severall Shieres of Wales. That where the bearer hereof Christofer Saxton is appointed by her Maiestie vnder her signe and signet to set forth and describe Coates [Cartes] in particulerlie all the shieres in Wales. That the said Justices shalbe aiding and assisting vnto him to see him conducted vnto any towre Castle highe place or hill to view that country, and that he maybe accompanied with ij or iij honest men such as do best know the cuntrey for the best accomplishment of that service, and that at his departure from any towne or place that he hath taken the view of said towne do set forth a horseman that speak both welshe and englishe to safe conduct to the next market Towne, etc

“…any towre Castle highe place or hill to view that country…” strongly suggests triangulation.

There are 35 maps, each bearing the arms of the Queen and Thomas Seckford. Drawn by Saxton the maps were engraved by Augustine Ryther (5 maps) the only engraver who clearly identifies as English, Remigius Hogenberg (9 maps),Leonard Terwoort of Antwerp (5 maps), Cornelius Hogius (1 map), Johannes Rutlinger (1 map) all four of whom were Flemish, Francis Scatter (2 maps), Nicholas Reynold (1 maps) are both of uncertain origin. Of the remaining unsigned maps five are definitely engraved in the Flemish style. In general there are clearly Flemish elements in the style of all the maps.

It is not known for certain when John Dee and Christopher Saxton became acquainted and whether Dee had an influence on Saxton, but when Dee, as Warden of Christ’s College, Manchester (1595–1605), became involved in a boundary dispute he employed Saxton as his surveyor to settle the argument.

Although it sold well, Saxton’s atlas was not without its critics. Although some counties are presented on separate maps others are grouped together on one map. For example the 13 Welsh counties are presented on 7 maps or Kent, Sussex, Surry, Middlesex and London are all on one map. Because of the pages are uniform in size the map scales vary considerably. Also although the maps initially appear homogeneous the symbols used vary considerably from map to map, even between maps engraved by the same engraver.  None of Saxton’s maps have roads. All of these imperfections led to various attempts to improve on Saxton’s work.

The first of these was John Norden (c. 1547–1625), who started a series of county histories, each accompanied by a map, entitled Speculum Britanniae.


John Norden Source

The first volume Speculum Britanniae: the First Parte: an Historicall, & Chorographicall Discription of Middlesexwas published in 1593. The manuscript is in the British Library with corrections in Burghley’s handwriting, which points to Burghley being Norden’s sponsor. 1595 he wrote a manuscript “Chorographical Description” of Middlesex, Essex,Surry,Sussex,Hampshire, Wight, Guernsey andJersey, dedicated to Queen Elizabeth. In 1596 he published his Preparative to the Speculum Britanniae, dedicated to Burghley. The only other volume published by Norden was Speculi Britaniae Pars: the Description of Hartfordshirein 1598. He completed accounts of five other counties in manuscript of which three were published posthumously in 1720, 1728 and 1840. It was probably Burghley’s death in 1598 that put an end to Norden’s project.


John Norden’s map of Essex 1595 Source: British Library

The next attempt was undertaken by a friend and colleague of Norden’s, William Smith (c.1550–1618), antiquarian and Rouge Dragon at the College of Heralds. Unlike Norden, who had never left England, Smith spent five years living in Nürnberg, a major cartographical centre. In 1588 Smith completed The Particuler Description of England With The Portratures of Certaine the Chieffest Citties and Townes. Between 1602 and 1603 Smith anonymously published maps of Chester, Essex, Hertfordshire, Lancashire, Leicester, Norfolk Northamptonshire, Staffordshire, Suffolk, Surry, Warwickshire and Worcester probably engraved in Amsterdam and intended as sheets for a new atlas. Smith’s maps contain the roads missing from Saxton’s maps. It is thought that Smith abandoned his atlas project because of competition from John Speed (1551 or 52–1629)


William Smith map of Lancashire 1598 Source: British Library

Speed born in Farndon, Cheshire followed his father into the tailoring business. Moving to London he became a Freeman of the Merchant Taylor’s Guild, who devoted his free time to cartography.


John Speed Source: My facsimile copy

This activity attracted the attention of Sir Fulke Greville, 1stBaron Brooke (1554–1628) a leading Elizabethan statesman, who secured him a position at the Customs and with the support of the Queen, subsidized his map making.


Fulke Greville, 1st Baron Brooke Portrait by Edmund Lodge Source: Wikimedia Commons

A member of the society of Antiquities he became friends with such people as the historian William Camden (1551–1623) and the cartographer William Smith, who assisted him with his research. Speed published his atlas, The Theatre of the Empire of Great Britaine, which was dated 1611 in 1612. He regarded it as a supplement to his Historie of Great Britainepublished in 1611. The use of the word theatre in the title reflects the influence of Ortelius, whose own The Theatre of the World was published in English in 1606. The Empire of Great Britain is a term introduced by John Dee.


Speed title page Source: My facsimile copy

Whereas Christopher Saxton was a trained surveyor, who went out surveyed and drew his own maps, John Speed was a compiler who took his maps from various sources, including Saxton, and merely redrew them to a homogenous standard. Apart from Saxton (5 maps), Speed credits maps from John Norden (5), William Smith (2) and individual maps from Philip Symonson, John Harrington, William White, Thomas Durham and James Burrell. His maps of Wales are obviously based on Saxton’s although he doesn’t credit him. His of Ireland, which Saxton did not include in his atlas, are based on the work of Robert Lythe and Robert Jobson. However although not by him he doesn’t credit the majority of his maps. All of Speed’s maps were engraved by the Dutch engraver, Jodocus Hondius (1563–1612), who was himself one of the leading European cartographers and globe makers.

Obviously inspired by Saxton’s work Speed’s Theatre differs in that he includes Ireland and Scotland, both missing by Saxton. He gives each county a separate map and although he cannot reproduce them all to the same scale, due to page size, Like Saxton he includes a scale bar on each map. However, it is not known what length for the mile Speed used. His symbols are uniform through the entire book and on the back of each map sheet he includes topographical, administrative and historical comments. The margins of the maps often include the arms of the leading families or other informative historical drawings and following William Smith he includes plans and maps of the principle towns and cities. Speed’s Theatre is altogether a much more attractive and informative work than Saxton’s atlas even though it very clearly owes it existence to the earlier pioneering work, so it is fair to speak of a Saxon/Speed presentation of the counties of Britain.



The Eastern half of Saxton’s map of Essex (above) Speed’s version of the same (below ) to illustrate the similarities and the differences. The place where I spent the first fifteen years of my life, Thorp (now Thorpe-le-Soken) is roughly in the middle of the Tendering Hundred in the North-East corner of the county. Going south from there Little Clacton and Great Clacton are both marked but my birthplace on the coast, Clacton-on-Sea, obviously didn’t exist yet when the maps were drawn. Speed’s map contains a plan of the town of Colchester, “Britain’s oldest town”, where I went to school.

Unlike the Netherlands, where the fierce competition between the houses of Blaeu and Hondius led to ever better, ever more spectacular atlases and globes throughout the seventeenth century, following the publication of Speed’s Theatre, cartography on that scale ceased almost entirely in Britain. This meant that Speed’s Theatreremained the standard cartographical work in Britain for more than one hundred years. The burst of cartographical activity between Rudd and Speed remained a bubble rather than the start of tradition, as Gemma Frisius’, Abraham Ortelius’ and Gerard Mercator’s work had become in the Netherlands.











1 Comment

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

A sixteenth century bestseller by an amateur cosmographer

Sebastian Münster, who with his Cosmographia wrote and published what was probably the biggestselling book in the sixteenth century, was actually a professor for Hebrew by profession and only a passionate cosmographer in his free time. Born in Ingelheim am Rhein 20 January 1488 as the son of Endres Münster a churchwarden and master of the church hospital.


Sebastian Münster portrait by Christoph Amberger c. 1550 Source: Wikimedia Commons


Münster’s birthplace Ingelheim from the Cosmographia Source: Wikimedia Commons

He studied at a Franciscan school and entered the Order in 1505. In 1507 he was sent to Löwen and then Freiburg im Breisgau, where he studied under Gregor Reisch (c. 1467–1525), author of the well known encyclopaedic student textbook the Margarita Philosophica, in particular geography and Hebrew.


Ptolemeus and Astronomia from Gregor Reisch’s Margarita Philosophica Source: Wikimedia Commons

In 1509 he became a pupil of the humanist scholar Konrad Pelikan (1478–1556), who over the next five years taught him Hebrew, Greek, mathematics, and cosmography. In 1512 he was anointed a priest. Pelikan and Münster expanded their studies to include other Semitic languages, in particular Aramaic and Ethiopian.


Konrad Pelikan Source: Wikimedia Commons

From 1514 to 1518 he taught at the Franciscan high school in Tübingen. Parallel to his teaching he studied astrology, mathematics and cosmography under Johannes Stöffler. From 1518 he taught at the Franciscan high school in Basel and from 1521 to 1529 at the University of Heidelberg. In 1529 he left the Franciscan Order and became professor for Hebrew at the University of Basel as Pelikan’s successor, converting to Protestantism. In 1530 he married Anna Selber the widow of the printer/publisher Adam Petri, the cousin and printing teacher of Johannes Petreius. As a Hebraist he published extensively on language, theology and the Bible but it is his work as a cosmographer that interest us here. All of his books were published by his stepson Heinrich Petri.

In 1528 he published a pamphlet entitled Erklärung des neuen Instruments der Sunnen(Explanation of a new instrument of the Sun) in which he issued the following request, Let everyone lend a hand to complete a work in which shall be reflected…the entire land of Germany with all its territories, cities, towns, villages, distinguished castles and monasteries, its mountains, forests, rivers, lakes, and its products, as well as the characteristics and customs of its people, the noteworthy events that have happened and the antiquities which are still found in many places. He gave his readers instructions on how to record an area cartographically from a given point. This is the earliest indication of Münster’s intension to create a full geographical description of the German Empire. This first appeal proved in vain; it would be another sixteen years before he realised this high ambition. Münster satisfied himself with the publication of a small pamphlet Germaniae descriptioin 1530 based on a revised edition of a map of Middle Europe from Nicolaus Cusanus.

Turning his attention to ancient Greek geography Münster published Latin editions of Solinus’ Polyhistorand Pomponius Mela’s De situ orbis. In 1532 Münster drew a world map for Simon Grynaeus’ and Johann Huttich’s popular travel book Novus Orbis Regionum(“New World Regions”, which described the journeys of famous explorers. The map in not particular innovative and does not go much further in its information than the 1507 Waldseemüller world map. However it does contain a border of fascinating illustrations thought to have been created by Hans Holbein, who in his youth had worked for the Petri publishing house.


Münster’s 1532 World Map

In 1540 Münster issued his edition of Ptolemaeus’ Geographia, which was based on the Latin translation by Willibald Pirckheimer. His edition entitled, Geographia universalis, vetus et nova(“Universal Geography, Old and New”) was the first work to contain separate maps for each of the then four continents. In total the work contain forty-six maps drawn by Münster. The world map in this work differs substantially from the one from 1532.


Münster’s map of America Source: Wikimedia Commons

Münster’s  magnum opus his Cosmographiaor to give it its full title:

Cosmographia. Beschreibung aller Lender durch Sebastianum Münsterum: in welcher begriffen aller Voelker, Herrschaften, Stetten, und namhafftiger Flecken, herkommen: Sitten, Gebreüch, Ordnung, Glauben, Secten und Hantierung durch die gantze Welt und fürnemlich Teütscher Nation (Getruckt zu Basel: durch Henrichum Petri 1544)


Cosmographia title page

finally appeared in 1544 with contributions from over one hundred scholars from all over Europe, who provided maps and texts on various topics for inclusion in what was effectively an encyclopaedia. Over the next eighty years the work was published in thirty-seven editions, in German (21), Latin (5), French (6), Italian (3), Czech (1) and English (1) (although the English edition is an incomplete translation). The work was continually revised and expanded, the 1544 original had 600 pages and the final edition from 1628 1800. The work was published in six volumes, which in the 1598 edition were as follows:

Book I: Astronomy, Mathematics, Physical Geography, Cartography

Book II: England, Scotland, Ireland, Spain, France, Belgium, The Netherlands, Luxembourg, Savoy, Trier, Italy

Book III: Germany, Alsace, Switzerland, Austria, Carniola, Istria, Bohemia, Moravia, Silesia, Pomerania, Prussia, Livland

Book IV: Denmark, Norway, Sweden, Finland, Iceland, Hungary, Poland, Lithuania, Russia, Walachia, Bosnia, Bulgaria, Serbia, Greece, Turkey

Book V: Asia Minor, Cyprus, Armenia, Palestine, Arabia, Persia, Central Asia, Afghanistan, Scythia, Tartary India, Ceylon, Burma, China, East Indies, Madagascar, Zanzibar, America

Book VI: Mauritania, Tunisia, Libya, Egypt, Senegal, Gambia, Mali, South Africa, East Africa


Town plan of Bordeaux from the Cosmographia Source: Wikimedia Commons

As indicated in his original call for cooperation, Münster’s Cosmographia was much more than a simple atlas mapping the world but was an integrated description combining geography, cartography, history and ethnography to create an encyclopaedic depiction of the known world.


Chartre under attack from the Cosmographia Source: Wikimedia Commons

In total at least 50,000 German copies and 10,000 Latin ones left the Petri printing house in Basel over the eight-four years the book was in print, making it probably the biggest selling book, with the exception of the Bible, in the sixteenth century. The Cosmographiaset new standards in ‘modern’ geography and cartography and paved the way for the Civitates Orbis Terrarumof Georg Braun and Frans Hogenberg in 1572, the TheatrumOrbis Terrarum from Abraham Ortelius from 1570 and Mercator’s Atlas from 1595. Despite the competition from the superior atlases of Ortelius and Mercator, the Cosmographiasold well up to the final edition of 1628.

Münster’s Cosmographiais without a doubt a milestone in the evolution of modern cartography and geography and he deserves to be better known than he is. Bizarrely, although they mostly aren’t aware of it, Germans of a certain age are well aware of what Münster looks like, as his portrait was used for the 100 DM banknote from 1961 to 1995, when he was replaced by Clara Schumann.


Source: Wikimedia Commons



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

Maximilian and the Mathematici–astrology as political propaganda

For a long time most historians of science tried their best to ignore the history of astrology, basically sweeping it under the carpet where and when it poked its nose into their area of study. More recently this began to change with more and more historians acknowledging that astrology played a role in a large part of human history, although  most of them still treated it as some sort of largely irrelevant side issue that one could mention in passing, if necessary, and then safely ignore. However in large phases of European history astrology permeated all levels of society and was just as much a central factor of life as religion or politics. This was certainly very much the case in the Renaissance. A number of historians have begun to examine in depth the role that astrology played and present their findings in books and articles; one such book is Darin Hayton’s The Crown and the Cosmos: Astrology and the Politics of Maximilian I.[1]


Maximilian I (1486–1519) was an Austrian Habsburg, who was King of the Romans (also known as King of the Germans) from 1486 and Holy Roman Emperor from 1508 until his death.


Albrecht Dürer – Portrait of Maximilian I Source: Wikipedia Commons

Through marriage he became Duke of Burgundy and his son Philip the Handsome through his marriage to Joanna of Castile, arranged by Maximilian, established the Spanish Habsburg dynasty. As such Maximilian played a very important role in late medieval European history. Throughout his life Maximilian was involved in complex and protracted political and military campaigns and Hayton’s book illustrates in detail how Maximilian used astrology as political propaganda to further his aims in those multifarious campaigns.

Throughout his life Maximilian was associated with and actively promoted a significant number of well-known astrological mathematici, several of whom have over the years featured in various blog posts here. As Hayton explains, through his active promotion of the astrologers Maximilian wanted to present himself as a knowledgeable man of science, as erudite and educated. Maximilian’s close connection with astrology began with his birth, when his parents, the Holy Roman Emperor, Frederick III and Eleanor, infanta of Portugal, requested Regiomontanus to cast Maximilian’s natal horoscope. Regiomontanus was only twenty-three years old at the time. Regiomontanus’ teacher Peuerbach had been an astrological advisor to Frederick for some time and had cast Eleanor’s horoscope before the royal marriage.

In the early phase of his career Maximilian used the humanist scholars, Joseph Grünpeck (c. 1473–after 1530) (author of one of the first texts on the French Disease aka syphilis)


Only known portrait of Joseph Grünpeck – artist unknown

and Sebastian Brant (1457–1521) (author of Das Narrenschiff (Ship of Fools))


Sebastian Brant by Albrecht Dürer Source: Wikimedia Commons

to employ their poetical and astrological skills in helping him to create idealised works of autobiography presenting Maximilian as he whished to be viewed as a future Holy Roman Emperor. This was part of a much wider astrological propaganda campaign presenting Maximilian, as the ideal candidate for the position of power.

In a second element of his campaign Maximilian revitalised the University of Vienna, returning it to the high status it had when Georg Peuerbach (1423–1461) and Johannes Regiomontanus (1436–1476) represented the first Viennese School of Mathematics, as the heirs of Johannes von Gmunden (c. 1380–1442). A period, which had ended in 1561 when Peuerbach died and Regiomontanus left Vienna for Italy with Basilios Bessarion (c. 1400–­1472).

At the beginning of the sixteenth century Maximilian brought Conrad Celtis (1495–1508), the Arch-Humanist, from Ingolstadt to Vienna and established for him the Collegium poetarum et mathematicorum. Two professors for mathematics were installed Andreas Stiborius (c. 1464–1515) and Johannes Stabius (1450–1522), both also from Ingolstadt. Stabius was however soon promoted to court historian.


Albrecht Dürer’s portrait of Johannes Stabius Source: Wikimedia Commons

The two also brought their favourite pupil with them, Georg Tannstetter (1482–1535), who would go on to make a long and successful career in Vienna.


Georg Tannstetter Portrait ca. 1515, by Bernhard Strigel Source: Wikimedia Commons

Tannstetter would be succeeded by his own pupil Andreas Perlach (1490–1551). These men constitute the so-called second Viennese School of Mathematics.

Having dealt with Maximilian’s use of astrology in his autobiographies and his political propaganda in the opening chapters, Hayton deals in successive chapters with the various aspects of astrology–teaching of the subject, astrological instruments, wall calendars and practica, ephemerides, prognostications–and how these were used by their producers to support and enable Maximilian’s political aims and ambitions. This is all down in substantive detail illustrating nicely how the work of the mathematici and their patron created a symbiosis serving the needs of both sides. In the chapter on Perlach and his ephemerides Hayton gives a very nice analysis of Perlach’s readers, based on the hand written marginalia found in the surviving copies of his texts.

It should be noted that this service of the Viennese mathematicians did not end with Maximilian’s death in 1519. Both Tannstetter and Perlach carried on producing their astrological publications in the political interest of the Habsburgs for Maximilian’s grandsons, Ferdinand Archduke of Austria (1503–1564) and Charles V (1500–1558) Holy Roman Emperor and Emperor of the Spanish Empire, Maximilian was predeceased by their father, his son Philip the Handsome.


Ferdinand Archduke of Austria Portrait by Hans Bocksberger the Older Source: Wikimedia Commons


Charles V by Juan Pantoja de la Cruz Source: Wikimedia Commons

The book is nicely illustrated with grey tone reproductions of the texts and their illustration from the various publications. There are extensive, informative endnotes, an equally extensive bibliography of primary and secondary sources and a useful index.

Hayton has written an important study on the political use of astrology by those in a centre of power during the Renaissance that can be profitably be read in tandem with Monica Azzolini’s The Duke and the Stars, which I reviewed some time ago. As Hayton says in his introduction historians of the period need to include the history of astrology in their studies and historians of astrology need to look more closely at the general historical picture. Hayton has excellently fulfilled his own demand.




[1]Darin Hayton, The Crown and the Cosmos: Astrology and the Politics of Maximilian I, University of Pittsburgh Press, Pittsburgh, 2015


Filed under Book Reviews, History of Astrology, Renaissance Science

Renaissance mathematics and medicine

Anyone who read my last blog post might have noticed that the Renaissance mathematici Georg Tannstetter and Philipp Apian were both noted mathematicians and practicing physicians. In our day and age if someone was both a practicing doctor of medicine and a noted mathematician they would be viewed as something quite extraordinary but here we have not just one but two. In fact in the Renaissance the combination was quite common. Jakob Milich, who studied under Tannstetter in Vienna, was called to Wittenberg by Philipp Melanchthon in 1524, as professor for mathematics, where he taught both Erasmus Reinhold and Georg Joachim Rheticus. In 1536 he became professor for anatomy in Wittenberg and was succeeded by Rheticus as professor for mathematics. Rheticus in turn would later become a practicing physician in Krakow. The man, who Rheticus called his teacher, Nicolaus Copernicus, was another mathematical physician. My local Renaissance astronomer Simon Marius was another mathematician who studied and practiced medicine. That this was not a purely Germanic phenomenon is shown by the Welsh mathematicus and physician Robert Recorde and most notably by the Italian Gerolamo Cardano, who is credited with having written the first modern maths book, his Ars magna, and who was one of the most renowned physicians in Europe in his day.

These are only a few well-known examples but in fact it was very common for Renaissance mathematician to also be practicing physicians, so what was the connecting factor between these, for us, very distinct fields of study? There are in two interrelated factors that have to be taken into consideration, the first of which is astrology. The connection between medicine and astrology has a long history.

Greek legend says that Babylonian astrology was introduced into Greece by the Babylonian priest Berossus, who settled on the island of Kos in the third century BCE. Kos was the home of the Hippocratic School of medicine and astrology soon became an element in the Hippocratic Corpus. At the same time the same association between astrology and medicine came into Greek culture from Egypt in the form of the Greek-Egyptian god Hermes Trismegistos. Both the Egyptians and Babylonians had theories of lucky/unlucky, propitious/propitious days and these were integrated into the mix in the Greek lunar calendar. The Greeks developed the theory of the zodiac man, assigning the signs of the zodiac to the various part of the body. If a given part of the body was afflicted it would then be treated with the plants and minerals associated with its zodiac sign. The central role of astrology in medicine can be found in both the Hippocratic Corpus, in Airs, Waters, Placesit is stated that “astronomy is of the greatest assistance to medicine”and in Ptolemaeus’ Tetrabibloswe read, “The nature of the planets produce the forms and causes of the symptoms, since of the most important parts of man, Saturn is lord of the right ear, the spleen, the bladder, phlegm and the bones; Jupiter of touch, the lungs, the arteries and the seed; Mars of the left ear, the kidneys, the veins and the genitals; the sun of sight, the brain, the heart, the sinews and all on the right side; Venus of smell, the liver and muscles; Mercury of speech and thought, and the tongue, the bile and the buttocks; and the Moon of taste and of drinking, the mouth, the belly, the womb and all on the left side.” The connection between astrology was firmly established in Greek antiquity and was known as iatromathematica, health mathematics.

The theory of astrological medicine disappeared in Europe along with the rest of early science in the Early Medieval Period but was revived in the eighth century in the Islamic Empire when they took over the accumulated Greek Knowledge. The basic principles were fully accepted by the Islamic scholars and propagated down the centuries. When the translators moved into Spain and Sicily in the twelfth century they translated the Greek astrology and astrological medicine into Latin from Arabic along with rest of the Greek and Arabic sciences.

During the High Middle Ages, Christian scholars carried on an energetic debate about the legitimacy, or lack of it, of astrology. This debate centred on judicial astrology, this included natal astrology, mundane astrology, horary astrology, and electional astrology but excluded so called natural astrology, which included astrometeorology and astro-medicine both of which were regarded as scientific. To quote David Lindberg, “…no reputable physician of the later Middle Ages would have imagined that medicine could be successfully practiced without it.”


Woodcut of the Homo Signorum, or Zodiac Man, from a 1580 almanac. Source: Wikipedia Commons

Beginning in the fifteenth century during the humanist renaissance astrological medicine became the mainstream school medicine. It was believed that the cause, course and cure of an illness could be determined astrologically. In the humanist universities of Northern Italy and Poland dedicated chairs of mathematics were established, for the first time, which were actually chairs for astrology with the principle function of teaching astrology to medical students. Germany’s first dedicated chair for mathematics was founded at the University of Ingolstadt in about 1470 for the same reason.


Zodiac Man The Très Riches Heures du Duc de Berry c. 1412 Source: Wikimedia Commons

With the advent of moving type printing another role for mathematicians was producing astronomical/astrological calendars incorporating the phases of the moon, eclipses and other astronomical and astrological information needed by physicians to determine the correct days to administer blood lettings, purges and cuppings. These calendars were printed both as single sheet wall calendars and book form pocket calendars.


Renaissance Wall Calendar, 1544 Source: Ptak Science Books

These calendars were a major source of income for printer/publishers and for the mathematici who compiled them. Before he printed his legendary Bible, Johannes Guttenberg printed a wall calendar. Many civil authorities appointed an official calendar writer for their city or district; Johannes Schöner was official calendar writer for Nürnberg, Simon Marius for the court in Ansbach, Peter Apian for the city of Ingolstadt and Johannes Kepler for the city of Graz. Official calendar writers were still being employed in the eighteenth century. As I explained in an earlier post the pocket calendars led to the invention of the pocket diary.

Marius: [Alter und Newer Schreibcalender], [1602]  (Scan Nr. 150)

Simon Marius: Alter und Newer SchreibCalender auf das Jahr 1603 Title page Source: Deutsches Museum

With mainstream medicine based on astrology it was a short step for mathematicians to become physicians. Here we also meet the second factor. As a discipline, mathematics had a very low status in the Early Modern Period; in general mathematicians were regarded as craftsmen rather than academics. Those who worked in universities were at the very bottom of the academic hierarchy. At the medieval university it was only possible for graduates to advance to a doctorate in three disciplines, law, theology and medicine. It was not possible to do a doctorate in mathematics. With the dominance of iatromathematica, which depended on astrology, for which one in turn needed astronomy, for which one needed mathematics it was logical for mathematicians who wished to take a university doctorate, in order to gain a higher social status, to do so in medicine. The result of this is a fascinating period in European history from about 1400 to middle of the seventeenth century, where many of the leading mathematicians were also professional physicians. When astrology lost its status as a science this period came to an end.





Filed under History of Astrology, History of Astronomy, History of Mathematics, History of medicine, Renaissance Science, Uncategorized

The Bees of Ingolstadt

The tittle of this blog post is a play on the names of a father and son duo of influential sixteenth century Renaissance mathematici. The father was Peter Bienewitz born 16 April 1495 in Leisnig in Saxony just south of Leipzig. His father was a well off shoemaker and Peter was educated at the Latin school in Rochlitz and then from 1516 to 1519 at the University of Liepzig. It was here that he acquired the humanist name Apianus from Apis the Latin for a bee, a direct translation of the German Biene. From now on he became Petrus Apianus or simply Peter Apian.


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

In 1519 he went south to the University of Vienna to study under Georg Tannstetter a leading cosmographer of the period.


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

Tannstetter was a physician, mathematician astronomer and cartographer, who studied mathematics at the University of Ingolstadt under Andreas Stiborius and followed Conrad Celtis and Stiborius to Vienna in 1503 to teach at Celtis’ Collegium poetarum et mathematicorum. The relationship between teacher and student was a very close one. Tannstetter edited a map of Hungary that was later printed by Apian and the two of them produced the first printed edition of Witelo’s Perspectiva, which was printed and published by Petreius in Nürnberg in 1535. This was one of the books that Rheticus took with him to Frombork as a gift for Copernicus.

In 1520 Apian published a smaller updated version of the Waldseemüller/ Ringmann world map, which like the original from 1507 named the newly discovered fourth continent, America. Waldseemüller and Ringmann had realised their original error and on their 1513 Carte Marina dropped the name America, However, the use by Apian and by Johannes Schöner on his 1515 terrestrial globe meant that the name became established.


Apian’s copy of the Waldseemüller world map, naming the new fourth continent America Source: Wikimedia Commons

Apian graduated BA in 1521 and moved first to Regensburg then Landshut. In 1524 he printed and published his Cosmographicus liber, a book covering the full spectrum of cosmography – astronomy, cartography, navigation, surveying etc. The book became a sixteenth century best seller going through 30 expanded editions in 14 languages but after the first edition all subsequent editions were written by Gemma Frisius.


Title page of Apian’s Cosmpgraphia

In 1527 Apian was called to the University of Ingolstadt to set up a university printing shop and to become Lektor for mathematics. He maintained both positions until his death in 1552.

In 1528 he printed Tannstetter’s Tabula Hungariaethe earliest surviving printed map of Hungary. In the same year Apian dedicated his edition of Georg von Peuerbach’s New Planetary Theory to his “famous teacher and professor for mathematics” Tannstetter.


Tabula Hungarie ad quatuor latera Source: Wikimedia Commons

One year earlier he published a book on commercial arithmetic, Ein newe und wolgegründete underweisung aller Kauffmanns Rechnung in dreyen Büchern, mit schönen Regeln und fragstücken begriffen(A new and well-founded instruction in all Merchants Reckoning in three books, understood with fine rules and exercises). It was the first European book to include (on the cover), what is know as Pascal’s triangle, which was known earlier to both Chinese and Muslim mathematicians.


This is one of the volumes lying on the shelf in Holbein’s painting The Ambassadors. Like his Cosmographicusit was a bestseller.

In the 1530s Apian was one of a group of European astronomers, which included Schöner, Copernicus, Fracastoro and Pena, who closely observed the comets of that decade and began to question the Aristotelian theory that comets are sublunar meteorological phenomena. He was the first European to observe and publish that the comet’s tail always points away from the sun, a fact already known to Chinese astronomers. Fracastoro made the same observation, which led him and Pena to hypothesise that the comet’s tail was an optical phenomenon, sunlight focused through the lens like translucent body of the comet. These observations in the 1530s led to an increased interest in cometary observation and the determination in the 1570s by Mästlin, Tycho and others that comets are in fact supralunar objects.


Diagram by Peter Apian from his book Astronomicum Caesareum (1540) demonstrating that a comet’s tail points away from the Sun. The comet he depicted was that of 1531, which we now know as Halley’s Comet. Image courtesy Royal Astronomical Society.

Through the Cosmographicus he became a favourite of Karl V, the Holy Roman Emperor, and Apian became the Emperor’s astronomy tutor. Karl granted him the right to display a coat of arms in 1535 and knighted him in 1541. In 1544 Karl even appointed him Hofpfalzgraf (Imperial Count Palatine), a high ranking court official.

Apian’s association with Karl led to his most spectacular printing project, one of the most complicated and most beautiful books published in the sixteenth century, his Astronomicum Caesareum (1540). This extraordinary book is a presentation of the then Standard Ptolemaic astronomy in the form of a series of highly complex and beautifully designed volvelles. A vovelle or wheel chart is a form of paper analogue computer. A series of rotating paper discs mounted on a central axis or pin that can be used to calculate various mathematical functions such as the orbital positions of planets.


Astronomicum Caesareum title page

The Astronomicum Caesareumcontains two volvelles for each planet, one to calculate its longitude for a given time and one to calculate its latitude.


Astronomicum Caesareum volvelle for longitude for Saturn


Astronomicum Caesareum volvelle for the latitude for Saturn

There is also a calendar disc to determine the days of the week for a given year.


Astronomicum Caesareum calendar volvelle

Finally there are vovelles to determine the lunar phases  as well as lunar and solar eclipse.


Astronomicum Caesareum : Disc illustrating a total eclipse of the moon 6 Octobre 1530


Astronomicum Caesareum solar eclisse volvelle

Johannes Kepler was very rude about the Astronomicum Caesareum, calling it a thing of string and paper. Some have interpreted this as meaning that it had little impact. However, I think the reverse is true. Kepler was trying to diminish the status of a serious rival to his endeavours to promote the heliocentric system. Owen Gingerich carried out a census of 111 of the approximately 130 surviving copies of the book and thinks that these represent almost the whole print run. This book is so spectacular and so expensive that the copies rarely got seriously damaged of thrown away.

Like other contemporary mathematici Apian designed sundials and astronomical instruments as well as marketing diverse volvelles for calculation purposes. Apian died in 1552 and was succeeded on his chair for mathematics by his son Philipp, the second of the bees from Ingolstadt.

Philipp Apian was born 14 September 1531, as the fourth of fourteen children (nine sons and five daughters) to Peter Apian and his wife Katharina Mesner.


Philipp Apian painting by Hans Ulrich Alt Source: Wikimedia Commons

He started receiving tuition at the age of seven together with Prince Albrecht the future Duke of Bavaria, who would become his most important patron.


Duke Albrecht V of Bavaria Hans Muelich Source: Wikimedia Commons

He entered the University of Ingolstadt at the age of fourteen and studied under his father until he was eighteen. He completed his studies in Burgundy, Paris and Bourges. In 1552 aged just 21 he inherited his fathers printing business and his chair for mathematics on the University of Ingolstadt. As well as teaching mathematics at the university, which he had started before his father died, Philipp studied medicine. He graduated in medicine several years later during a journey to Italy, where he visited the universities of Padua, Ferrara and Bolgna.

In 1554 his former childhood friend Albrecht, now Duke of Bavaria, commissioned him to produce a new map of Bavaria. During the summers of the next seven years he surveyed the land and spent the following two years drawing the map. The 5 metres by 6 metres map at the scale of 1:45,000, hand coloured by Bartel Refinger was hung in the library of the Bavarian palace.


Philipp Apian’s map of Bavaria

In 1566 Jost Amman produced 24 woodblocks at the smaller scale of 1:144,000, which Apian printed in his own print shop. Editions of this smaller version of the map continued to be issued up to the nineteenth century.


Overview of the 24 woodblock prints of Apian’s map of Bavaria

In 1576 he also produced a terrestrial globe for Albrecht. Map, woodblocks, woodblock prints and globe are all still extant.


Apian’s terrestrial globe

In 1568 Phillip converted to Protestantism and in the following year was forced by the Jesuit, who controlled the University of Ingolstadt to resign his post. In the same year, he was appointed professor for mathematics at the Protestant University of Tübingen. In Tübingen his most famous pupil was Michael Mästlin, who succeeded him as professor for mathematics at the university and would become Johannes Kepler’s teacher. An irony of history is that Philipp was forced to resign in Tübingen in 1583 for refusing to sign the Formal of Concord, a commitment to Lutheran Protestantism against Calvinism. He continued to work as a cartographer until his death in 1589.

There is a genealogy of significant Southern German Renaissance mathematici: Andreas Stiborius (1464–1515) taught Georg Tannstetter (1482–1535), who taught Peter Apian (1495–1552), who taught Philipp Apian (1531–1589), who taught Michael Mästlin (1550–1631), who taught Johannes Kepler (1571–1630)













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

Tycho’s last bastion

In the history of science, scholars who end up on the wrong side of history tend to get either forgotten and/or vilified. What do I mean by ‘end up on the wrong side of history’? This refers to scholars who defend a theory that in the end turns out to be wrong against one that in the end turns out to be right. My very first history of science post on this blog was about just such a figure, Christoph Clavius, who gets mocked by many as the last Ptolemaic dinosaur in the astronomy/cosmology debate at the beginning of the seventeenth century. In fact there is much to praise about Clavius, as I tried to make clear in my post and he made many positive contributions to the evolution of the mathematical sciences. Another man, who ended up on the wrong side of history in the same period is the Danish astronomer, Christen Sørensen, better known, if at all, by the name Longomontanus, the Latinised toponym based on Lomborg, the Jutland village where he was born on 4 October 1562 the son of a poor labourer, who died when he was only eight years old.


Longomontanus Source: Wikimedia Commons

Tycho Brahe backed the wrong astronomical theory in this period, a theory that is generally named after him although several people seem to have devised it independently of each other in the closing quarter of the sixteenth century. However, Tycho has not been forgotten because he delivered the new data with which Johannes Kepler created his elliptical model of the solar system. However, what people tend to ignore is that Tycho did not produce that data single-handedly, far from it.

The island of Hven, Tycho’s fiefdom, was a large-scale research institute with two observatories, an alchemy laboratory, a paper mill and a printing workshop.


Map of Hven from the Blaeu Atlas 1663, based on maps drawn by Tycho Brahe in the previous century Source: Wikimedia Commons

This enterprise was staffed by a veritable army of servants, technicians and research assistant with Tycho as the managing director and head of research.


Engraving of the mural quadrant from Brahe’s book Astronomiae instauratae mechanica (1598) Showing Tyco direction observations Source: Wikimedia Commons

Over the years the data that would prove so crucial to Kepler’s endeavours was collected, recorded and analysed by a long list of astronomical research assistants; by far and away the most important of those astronomical research assistants was Christen Sørensen called Longomontanus, who also inherited Tycho’s intellectual mantle and continued to defend his system into the seventeenth century until his death in 1647.

Christen Sørensen came from a very poor background so acquiring an education proved more than somewhat difficult. After the death of his father he was taken into care by an uncle who sent him to the village school in Lemvig. However, after three years his mother took him back to work on the farm; she only allowed him to study with the village pastor during the winter months. In 1577 he ran away to Viborg, where he studied at the cathedral school, supporting himself by working as a labourer. This arrangement meant that he only entered the university in Copenhagen in 1588, but with a good academic reputation. It was here at the university that he acquired his toponym, Longomontanus. In 1589 his professor recommended him to Tycho Brahe and he entered into service on the island of Hven.


Tycho Brahe’s Uraniborg main building from the 1663 Blaeu’s Atlas Major Centre of operations Source: Wikimedia Commons

He was probably instructed in Tycho’s methods by Elias Olsen Morsing, who served Tycho from 1583 to 1590, and Peter Jacobsen Flemløse, who served from 1577-1588 but stayed in working contact for several years more and became a good friend of Longomontanus. Longomontanus proved to be an excellent observer and spent his first three years working on Tycho’s star catalogue.


Stjerneborg Tycho Brahe’s second observatory on Hven: Johan Blaeu, Atlas Major, Amsterdam Source: Wikimedia Commons

Later he took on a wider range of responsibilities. In 1597, Tycho having clashed with the new king, the entire research institute prepared to leave Hven. Longomontanus was put in charge of the attempt to bring Tycho’s star catalogue up from 777 stars to 1,000. When Tycho left Copenhagen, destination unknown, Longomontanus asked for and received his discharge from Tycho’s service.

While Tycho wandered around Europe trying to find a new home for his observatory, Longomontanus also wandered around Europe attending various universities–Breslau, Leipzig and Rostock–and trying to find a new patron. He graduated MA in Rostock. During their respective wanderings, Tycho’s and Longomontanus’ paths crossed several times and the corresponded frequently, Tycho always urging Longomontanus to re-enter his service. In January 1600 Longomontanus finally succumbed and joined Tycho in his new quarters in Prague, where Johannes Kepler would soon join the party.

When Kepler became part of Tycho’s astronomical circus in Prague, Longomontanus the senior assistant was working on the reduction of the orbit of Mars. Tycho took him off this project putting him instead onto the orbit of the Moon and giving Mars to Kepler, a move that would prove history making. As should be well known, Kepler battled many years with the orbit of Mars finally determining that it was an ellipse thereby laying the foundation stone for his elliptical astronomy. The results of his battle were published in 1609, together with his first two laws of planetary motion, in his Astronomia nova.


Portrait of Johannes Kepler. Source: Wikimedia Commons

Meanwhile, Longomontanus having finished Tycho’s lunar theory and corrected his solar theory took his final departure from Tycho’s service, with letters of recommendation, on 4 August 1600.  When Tycho died 24 October 1601 it was thus Kepler, who became his successor as Imperial Mathematicus and inherited his data, if only after a long dispute with Tycho’s relatives, and not Longomontanus, which Tycho would certainly have preferred.

Longomontanus again wandered around Northern Europe finally becoming rector of his alma mater the cathedral school in Viborg in 1603. In 1605, supported by the Royal Chancellor, Christian Friis, he became extraordinary professor for mathematics at the University of Copenhagen, moving on to become professor for Latin literature in the same year. In 1607 he became professor for mathematics, and in 1621 his chair was transformed into an extraordinary chair for astronomy a post he held until his death.

As a professor in Copenhagen he was a member of an influential group of Hven alumni: Cort Aslakssøn (Hven 159-93) professor for theology, Christian Hansen Riber (Hven 1586-90) professor for Greek, as well as Johannes Stephanius (Hven 1582-84) professor for dialectic and Gellius Sascerides (Hven 1585-86) professor for medicine.

Kepler and Longomontanus corresponded for a time in the first decade of the seventeenth century but the exchange between the convinced supporter of heliocentricity and Tycho’s most loyal lieutenant was not a friendly one as can be seen from the following exchange:

Longomontanus wrote to Kepler 6th May 1604:

These and perhaps all other things that were discovered and worked out by Tycho during his restoration of astronomy for our eternal benefit, you, my dear Kepler, although submerged in shit in the Augean stable of old, do not scruple to equal. And you promise your labor in cleansing them anew and even triumph, as if we should recognise you as Hercules reborn. But certainly no one does, and prefers you to such a man, unless when all of it has been cleaned away, he understands that you have substituted more appropriate things in the heaven and in the celestial appearances. For in this is victory for the astronomer to be seen, in this, triumph. On the other hand, I seriously doubt that such things can ever be presented by you. However, I am concerned lest this sordid insolence of yours defile the excellent opinion of all good and intelligent men about the late Tycho, and become offensive.

Kepler responded early in 1605:

The tone of your reference to my Augean stable sticks in my mind. I entreat you to avoid chicanery, which is wont to be used frequently with regard to unpopular things. So that you might see that I have in mind how the Augean stable provided me with the certain conviction that I have not discredited astronomy – although you can gather from the present letter – I will use it with the greatest possible justification. But it is to be used as an analogy, not for those things that you or Tycho were responsible for constructing – which either blinded by rage or perverted by malice you quite wrongfully attributed to me – but rather in the comparison of the ancient hypotheses with my oval path2. You discredit my oval path. I hold up to you the hundred-times-more-absurd spirals of the ancients (which Tycho imitated by not setting up anything new but letting the old things remain). If you are angry that I cannot eliminate the oval path, how much more ought you to be angry with the spirals, which I abolished. It is as though I have sinned with the oval I have left, even though to you all the rest of the ancients do not sin with so many spirals. This is like being punished for leaving behind one barrow full of shit although I have cleaned the rest of the Augean stables. Or in your sense, you repudiate my oval as one wagon of manure while you tolerate the spirals which are the whole stable, to the extent that my oval is one wagon. But it is unpleasant to tarry in rebutting this most manifest slander.

 Whereas, as already mentioned above, Kepler presented his heliocentric theory to the world in 1609, Longomontanus first honoured Tycho’s memory with his Astronomia Danica in 1622. Using Tycho’s data Longomontanus provided planetary models and planetary tables for Tycho’s geo-heliocentric system. Longomontanus, however, differed from Tycho in that he adopted the diurnal rotation of Helisaeus Roeslin, Nicolaus Raimarus and David Origanus.


The Astronomia Danica saw two new editions in 1640 and 1663. For the five decades between 1620 and 1670 Kepler’s elliptical astronomy and the Tychonic geo-heliocentric system with diurnal rotation competed for supremacy in the European astronomical community with Kepler’s elliptical system finally triumphing.

 In 1625 Longomontanus suggested to the King, Christian IV, that he should build an observatory to replace Tycho’s Stjerneborg, which had been demolished in 1601. The observatory, the Rundetaarn (Round Tower), was conceived as part of the Trinitatis Complex: a university church, a library and the observatory. The foundation stone was laid on 7 July 1637 and the tower was finished in 1642. Longomontanus was appointed the first director of the observatory, after Leiden 1632 only the second national observatory in Europe.


Copenhagen – Rundetårn Source: Wikimedia Commons

Both Kepler and Longomontanus, who lost their fathers early, started life as paupers Both of them worked they way up to become leading European astronomers. Kepler has entered the pantheon of scientific gods, whereas Longomontanus has largely been assigned to the dustbin of history. Although Longomontanus cannot be considered Kepler’s equal, I think he deserves better, even if he did back the wrong theory.







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