Category Archives: History of Astronomy

The telescope – claims and counterclaims

Sometime between the 25thand 29thof September 410 years ago Hans Lipperhey, a spectacle maker from Middelburg in Zeeland, gave the earliest known public demonstration of the telescope to Maurits of Nausau and assembled company at a peace conference in Den Hague.


Source: Wikimedia Commons

His demonstration was recorded in a French newsletter, AMBASSADES DV ROY DE SIAM ENVOYE’ A L’ECELence du Prince Maurice, arriué à la Haye le 10. Septemb. 1608., recording the visit of the ambassador of the King of Siam (Thailand), who was also present at the demonstration.

A few days before the departure of Spinola from The Hague a spectacle-maker from Middelburg, a humble man, very religious & pious, offered His Excellency certain glasses as a present, by which one is able to trace & observe clearly objects at a distance of three or four miles, as if there is a distance as little as one hundred footsteps. From the tower of The Hague with the said glasses one can observe clearly the clock on the tower of Delft, & the windows of the Church of Leiden, despite the fact that one of the said towns is at a distance of one & a half hours and the other one at three and a half hours walking distance. The States-General were already well informed about this and sent them to His Excellency to show, adding that with these glasses one could observe the impostures of the enemy. Spinola also saw them with great astonishment & told Prince Hendrik; from this moment on I will not be safe anymore, because you can observe me from afar. Whereupon the said Prince answered: we will prohibit our people to shoot at you. The craftsman who has manufactured the said glasses has received three hundred écu & he will receive more on condition that he will tell nobody about the said proficiency, which he promised with most pleasure as he doesn’t want the enemy will be able to use this, The said glasses are very useful at sieges & in similar affairs, because one can distinguish from a mile’s distance & beyond several objects very well, as if they are very near & 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]

This was not however the first written account of Lipperhey’s new invention. The Councillors of Zeeland had given him a letter of introduction, dated 25 September, to the States-General in Den Hague, it begins:

The bearer of this, who claims to have a certain device, by means of which all things at a great distance can be seen as if they were nearby, by looking through glasses which he claims to be a new invention, would like to communicate the same to His Excellency [Prince Maurits]. Your Honour will please recommend him to His Excellency, and, as the occasion arises, be helpful to him according to what you think of the device…[2]

On 2 October 1608, Lipperhey submitted an application for a patent for his device to the States-General, from here on things, which had looked so promising for our humble spectacle-maker from Middelburg started to turn decidedly pear shaped.


Hans Lipperhey’s unsuccessfully patent request Source: Wikimedia Commons

On 14 October 1608, an, until now, unidentified young man offered to sell a telescope to the Councillors of Zeeland, who dutifully informed the States-General of this new development. On 15 October the States-General received a letter from Jacob Adriaenszoon (after 1571–1628) called Metius, a spectacle-maker from Alkmaar also requesting a patent for his instrument on which he had been working for two years and which, so he claimed, was a least as good as the instrument from Middelburg. Given these developments, telescopes were apparently available on every street corner, the States-General denied Lipperhey his desired patent but they did commission him to make six pairs of binoculars for a total of 900 guilders, a very large sum. Interestingly they demanded that the lenses be made of rock crystal rather than glass, because of the poor quality of the glass lenses, something that would remain a problem for telescope makers throughout the seventeenth century.

The problem with who actually invented the telescope does not end there. In his Mundus Jovialis, published in 1614, Simon Marius, one of the earliest telescopic astronomers, recounts how his patron Johan Philip Fuchs von Bimbach was offered a telescope at the Autumn Frankfurt Fair in 1608.


Engraved image of Simon Marius (1573-1624), from his book Mundus Iovialis, 1614 Source: Houghton Library via Wikimedia Commons

He didn’t purchase the proffered instrument because one of the lenses was cracked and the asking price was apparently too high. In many accounts of the invention of the telescope, this story is used as an illustration of how fast the new invention spread after Lipperhey’s unveiling in Den Hague. However, there is a major problem here; the Autumn Fair in Frankfurt in 1608 took place before Lipperhey’s demonstration. We have yet another unclear source for the ‘first telescope’.


Hans Philipp Fuchs von Bimbach Source: Wikimedia Commons

Up till 2008 it had become common practice to claim that the seller in Frankfurt and the unknown young man in Middelburg were one and the same and identified as Zacharias Janssen (1585-pre. 1632) and that he and not Lipperhey was the true inventor of the telescope and for good measure also the microscope.  How this all came about is almost Byzantine.


Zacharias Janssen Source: Wikimedia Commons

In 1655, the French scholar Pierre Borel (c. 1620–1671) published the first full history of the invention of the telescope, De vero telescopii inventore.


De vero telescopii inventore 1665 Title page Source

In his book he followed the account of the Dutch Ambassador to France, Willem Boreel (1591–1668). Born in Middelburg, Boreel had memories of having met the inventor of the telescope in 1610. Not sure of his memory forty-five years later he wrote to a local magistrate in Middelburg to investigate the matter. The magistrate interviewed a then unknown spectacle-maker Johannes Zachariassen, the son of Zacharias Janssen. Johannes claimed that his father and his grandfather had invented the microscope and telescope in 1590. Johannes would also tell a similar story to Isaac Beeckman, when he was teaching him lens grinding, also claiming that he and his father had also invented the long, i.e. astronomical, telescope in 1618. Boreel confirmed Johannes account as agreeing with his memories and Borel’s account that Zacharias Janssen and not Hans Lipperhey was the true inventor of the telescope.


Portrait of Pierre Borel by Jacques Pauthe Source: Wikimedia Commons

The last of Johannes’ claims is easily disposed of because it was Johannes Kepler, who first described the astronomical telescope in his Dioptrice in 1611. As to the other claim in 1590 Johannes’ grandfather was already dead and his father Zacharias was a mere four or five years old. These objections were simply swept aside over the years and Janssen’s invention simply moved forward to 1604 another date claimed by Johannes. However modern research by Huib Zuidervaart into the life of Zacharias Janssen have shown the first contact that he had with lens grinding or spectacle-making was when he became guardian the children of another spectacle-maker ‘Lowys Lowyssen, geseyt Henricxen brilmakers’. There is no other evidence that Zacharias was ever a spectacle-maker.[3]

The unknown youth in Middelburg and the telescope seller in Frankfurt remain unknown and probably forever unknowable.

News of the wonderful new invention spread really fast throughout Europe with telescopes on sale as novelties in Paris by the early summer 1609. The enthusiasm with which the new invention was greeted and the speed with which it spread throughout Europe rather puts the lie to all the competing theories that the telescope was already invented by (insert your favourite candidate) at some date before Lipperhey’s first demonstration. If it had been, we would certainly have heard about it. As far as we know, the first astronomer to make observations with the new instrument was Thomas Harriot, who drew a sketch of the moon observed with a six-power telescope dated 26 July 1609 os (5 August ns).


Harriot’s sketch of the moon 1609

Following on to his encounter with a telescope at the Frankfurt Fair, Fuchs von Bimbach together with Simon Marius obtained, with some difficulty, suitable lenses and the two of them constructed their own telescope. Simon Marius began his own astronomical observations sometime also in 1609. Galileo Galilei heard of the telescope through his friend Paolo Sarpi and it is now thought that his claim that he devised the construction of his telescope purely on the basis of having heard of it is not true and that he had in fact seen and handled a telescope before he began his own efforts at construction.


Galileo Galilei. Portrait by Ottavio Leoni Marucelliana Source: Wikimedia Commons

Galilei/ Fernrohre / Aufnahme

Galileo’s telescopes Source: Wikimedia Commons

Galileo, ever on the look out to make a quick buck and further his career, first marketed ‘his invention’ to the civil authorities, demonstrating a six-power telescope to the aristocrats of Venice 21 August 1609. On the 24thof the month he presented said telescope formally to the Doge and Senate of Venice. The following day the authorities granted him a lifetime contract as professor of mathematics at the university with the extraordinary salary of 1,000 florins p.a. with however the condition that he would never receive another pay rise. The Senate was apparently more than somewhat miffed when they discovered that the telescope was not the invention of their talented mathematics professor but was readily available on every street corner in Europe to knockdown prices. Galileo repaid their generosity by beginning plans to leave Venice and return to Florence.

We don’t know for certain when Galileo began his astronomical observations but we do know that he was an exceptionally talented observer and was soon viewing the skies on clear nights with a twenty-power instrument of his own construction. On 7 January 1610 he knew he had hit the jackpot when he first observed three of the moons of Jupiter. Simon Marius made the same discovery one day later on 8 January. More accurately he realised he had hit the jackpot only a couple of days later when it became clear that what he had discovered were satellites and not fixed stars. Marius waited four years before he published his discovery, Galileo didn’t! He immediately changed from Italian to Latin in his observing blog log and began making plans to publish his telescopic observation before he could be beaten to the gun by some unknown rival.

He decided to dedicate his planned publication to Cosimo II De’ Medici Fourth Grand Duke of Tuscany and started negotiations with the Tuscan Court over which names/names they would prefer for the newly discovered moons. In the end the term Medicean Stars was decided upon and Galileo’s Sidereus Nuncius was published with a preface dated forth day before the Ides of March 1610, that’s 12 March in modern money.


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

Seldom has a book hit the streets with such an impact. It truly marks the beginning of a new epoch in the history of astronomy and a new phase in the life of its author. Galileo got what he was angling for, he was appointed court mathematicus and philosophicus to the court in Florence and given a professorship at the university without teaching obligations but with a salary of 1,000 florins p.a.

The very poor quality of the glass available to make lenses and the errors in grinding and polishing made it very difficult for observers to see anything at all through the early telescopes, a problem that would continue to plague telescope users throughout the seventeenth century. There were as many claims made for discoveries that didn’t exist as for real ones.  All of this made it difficult for others to confirm Galileo’s spectacular claims. In the end the Jesuit astronomers of the Collegio Romano in Rome were able with much effort and many setbacks to confirm all of his discoveries. In 1611 he made a triumphant tour of Rome, which included a celebration banquet put on by the Jesuits at the Collegio. At a second banquet put on by Prince Frederico Cesi, founder and President of the Accademia dei Lincae of which Galileo would become a member, the telescope first received its name, in Greek teleskopos.

Another central problem in the first months of telescopic astronomical observation was that there existed no scientific explanation of how or why the telescope functions. This allowed critics to reject the discoveries as imaginary artefacts produced by the instrument itself. The man who came to the rescue was Johannes Kepler. Already in 1604 in his Ad Vitellionem Paralipomena Astronomiae pars optica, Kepler had published the first explanation of how lenses focus light rays and how eyeglasses work to compensate for short and long sightedness so he already had a head start on explaining how the telescope functions.

Francesco Maurolico (1494–1575) had covered much of the same ground in his Theoremata de lumine et umbra earlier than Kepler but this work was only published posthumously in 1611, so the priority goes to Kepler.


Source: Wikimedia Common


In 1611 Kepler published his very quickly written Diotrice, in which he covered the path of light rays through single lenses and then through lens combinations. In this extraordinary work he covers the Dutch or Galilean telescope, convex objective–concave eyepiece, the astronomical or Keplerian telescope, convex objective–convex eyepiece, the terrestrial telescope, convex objective–convex eyepiece–convex–field–lens to invert image, and finally for good measure the telephoto lens! Galileo’s response to this masterpiece in the history of geometrical optics was that it was unreadable!


Source: Wikimedia Commons

One small footnote to the whole who–invented–what story is that Kepler attributed the invention of the telescope to Giambattista della Porta (1535?–1615).


Giambattista della Porta Source: Wikimedia Commons

Della Porta did indeed describe the magnifying effect of the lens combination of the Dutch telescope in his Magiae Naturalis(various editions 1558 to 1589).

With a concave you shall see small things afar off, very clearly; with a convex, things neerer to be greater, but more obscurely: if you know how to fit them both together, you shall see both things afar off, and things neer hand, both greater and clearly.

He provided a primitive sketch in a letter to Prince Cesi in 1609.

Della Porta Telescope Sketch

Kepler assumed that the Dutch spectacle-maker, he didn’t know Lipperhey’s name, had somehow learnt of della Porta’s idea and put it into practice. It is more probable that della Porta was actually describing some sort of compound magnifying glass rather than a telescope and that Lipperhey had no idea of della Porta’s work.

Despite the confusion that surrounds the origins of the telescope, today most historians attribute the honours to Hans Lipperhey, whose demonstration set the ball rolling. We have come a long way since Lipperhey demonstrated his simple invention to Prince Maurits in Den Hague. I don’t suppose the humble spectacle–maker from Middelburg could have conceived the revolution in astronomy he set in motion on that day four hundred and ten years ago.

[1]Embassies of the King of Siam Sent to His Excellency Prince Maurits Arrived in The Hague on 10 September 1608,Transcribed from the French original, translated intoEnglish and Dutch, introduced by Henk Zoomers and edited by Huib Zuidervaart after a copy in the Louwman Collection of Historic Telescopes, Wassenaar, 2008 pp. 48-49 (original pagination: 9-11)

[2]Taken from Fred Watson, Stargazer: the life and times of the Telescope, Da Capo Press, Cambridge MA, 2005

[3]For more details of the Dutch story of the invention of the telescope see Huib J. Zuidervaart, The ‘true inventor’ of the telescope. A survey of 400 years of debate, in The origins of the telescope, ed. Albert van Helden, Sven Dupré, Rob van Gent, Huib Zuidervaart, KNAW Press, Amsterdam, 2010



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

The first calculating machine


Even in the world of polymath, Renaissance mathematici Wilhelm Schickard (1592–1635) sticks out for the sheer breadth of his activities. Professor of both Hebrew and mathematics at the University of Tübingen he was a multi-lingual philologist, mathematician, astronomer, optician, surveyor, geodesist, cartographer, graphic artist, woodblock cutter, copperplate engraver, printer and inventor. Born 22 April 1592 the son of the carpenter Lucas Schickard and the pastor’s daughter Margarete Gmelin he was probably destined for a life as a craftsman. However, his father died when he was only ten years old and his education was taken over by various pastor and schoolteacher uncles. Following the death of his father he was, like Kepler, from an impoverished background, like Kepler he received a stipend from the Duke of Württemburg from a scheme set up to provided pastors and teachers for the Protestant land. Like Kepler he was a student of the Tübinger Stift (hall of residence for protestant stipendiaries), where he graduated BA in 1609 and MA in 1611. He remained at the university studying theology until a suitable vacancy could be found for him. In 1613 he was considered for a church post together with another student but although he proved intellectually the superior was not chosen on grounds of his youth. In the following period he was appointed to two positions as a trainee priest. However in 1614 he returned to the Tübinger Stift as a tutor for Hebrew.


Wilhelm Schickard, artist unknown Source: Wikimedia Commons

Here we come across the duality in Schickard’s personality and abilities. Like Kepler he had already found favour, as an undergraduate, with the professor for mathematics, Michael Maestlin, who obviously recognised his mathematical talent. However, another professor recognised his talent for Hebrew and encouraged him to follow this course of studies. On his return to Tübingen he became part of the circle of scholars who would start the whole Rosicrucian movement, most notably Johann Valentin Andreae, the author of the Chymical Wedding of Christian Rosenkreutz, who also shared Schickard’s interest in astronomy and mathematics.


Johann Valentin Andreae Source: Wikimedia Commons

Although Schickard appear not to have been involved in the Rosicrucian movement, the two stayed friends and correspondents for life. Another member of the group was the lawyer Christian Besold, who would later introduce Schickard to Kepler.


Christopher Besold etching by Schickard 1618

This group was made up of the brightest scholars in Tübingen and it says a lot that they took up Schickard into their company.

In late 1614 Schickard was appointed as a deacon to the parish of Nürtingen; in the Lutheran Church a deacon is a sort of second or assistant parish pastor. His church duties left him enough time to follow his other interests and he initially produced and printed with woodblocks a manuscript on optics. In the same period he began the study of Syriac. In 1617 Kepler came to Württtemburg to defend his mother against the charge of witchcraft, in which he was ably assisted by Christian Besold, who as already mentioned introduced Schickard to the Imperial Mathematicus. Kepler was much impressed and wrote, “I came again and again to Mästlin and discussed with him all aspects of the [Rudolphine] Tables. I also met an exceptional talent in Nürtingen, a young enthusiast for mathematics, Wilhelm Schickard, an extremely diligent mechanicus and also lover of the oriental languages.” Kepler was impressed with Schickard’s abilities as an artist and printer and employed him to provide illustrations for both the Epitome Astronomiae Copernicanae and the Harmonice Mundi. The two would remain friends and correspondents for life.


3D geometrical figures from Kepler’s Hamonice Mundi by Schickard

In 1608 Schickard was offered the professorship for Hebrew at the University of Tübingen; an offer he initially rejected because it paid less than his position as deacon and a university professor had a lower social status than an on going pastor. The university decided to appoint another candidate but the Duke, whose astronomical advisor Schickard had become, insisted that the university appoint Schickard at a higher salary and also appoint him to a position as student rector, to raise his income. On these conditions Schickard accepted and on 6 August 1619 he became a university professor. Schickard subsidised his income by offering private tuition in Chaldean, Rabbinic, mathematic, mechanic, perspective drawing, architecture, fortification construction, hydraulics and optics.


Page from a manuscript on the comets of 1618 written and illustrated by Schickard for the Duke of Württemberg

The Chaldean indicates his widening range of languages, which over the years would grow to include Ethiopian, Turkish, Arabic and Persian and he even took a stab at Malay and Chinese later in life. Schickard’s language acquisition was aimed at reading and translating text and not in acquiring the languages to communicate. Over the years Schickard acquired status and offices becoming a member of the university senate in 1628 and a school supervisor for the land of Württemberg a year later.  In 1631 he succeeded his teacher Michael Mästlin as professor of mathematics retaining his chair in Hebrew. He had been offered this succession in 1618 to make the chair of Hebrew chair more attractive but nobody had thought that Mästlin, then almost 70, would live for another 12 years after Schickard’s initial appointment.


Michael Mästlin portrait 1619 the year Schickard became professor for Hebrew (artist unknown)

In 1624 Schickard set himself the task of producing a new, more accurate map of the land of Württemberg. Well read, he used the latest methods as described by Willebrord Snell in his Eratosthenes Batavus (1617).


This project took Schickard many more years than he originally conceived. In 1629 he published a pamphlet in German describing how to carry out simple geodetic surveys in the hope that others would assist him in his work. Like Sebastian Münster’s similar appeal his overture fell on deaf ears. Later he used his annual school supervision trips to carry out the necessary work.


Part of Schickard’s map of Württemberg

Schickard established himself as a mathematician-astronomer and linguist with a Europe wide reputation. As well as Kepler and Andreae he stood in regular correspondence with such leading European scholars as Hugo Grotius, Pierre Gassendi, Élie Diodati, Ismaël Boulliau, Nicolas-Claude Fabri de Peiresc, Jean-Baptiste Morin, Willem Janszoon Blaeu and many others.

The last years of Schickard’s life were filled with tragedy. Following the death of Gustav Adolf in the Thirty Years War in 1632, the Protestant land of Württemberg was invaded by Catholic troops. Along with chaos and destruction, the invading army also brought the plague. Schickard’s wife had born nine children of which four, three girls and a boy, were still living in 1634. Within a sort time the plague claimed his wife and his three daughters leaving just Schickard and his son alive. The invading troops treated Schickard with respect because they wished to exploit his cartographical knowledge and abilities. In 1635 his sister became homeless and she and her three daughters moved into his home. Shortly thereafter they too became ill and one after another died. Initially Schickard fled with his son to escape the plague but unable to abandon his work he soon returned home and he also died on 23 October 1635, just 43 years old, followed one day later by his son.

One of the great ironies of history is that although Schickard was well known and successful throughout his life, today if he is known at all, it is for something that never became public in his own lifetime. Schickard is considered to be the inventor of the first mechanical calculator, an honour that for many years was accorded to Blaise Pascal. The supporters of Schickard and Pascal still dispute who should actually be accorded this honour, as Schickard’s calculator never really saw the light of day before the 20thcentury. The story of this invention is a fascinating one.

Inspired by Kepler’s construction of his logarithm tables to simplify his astronomical calculation Schickard conceived and constructed his Rechenuhr (calculating clock) for the same purpose in 1623.

The machine could add or subtract six figure numbers and included a set of Napier’s Bones on revolving cylinders to carry out multiplications and divisions. We know from a letter that a second machine he was constructing for Kepler was destroyed in a workshop fire in 1624 and here the project seems to have died. Knowledge of this fascinating invention disappeared with the deaths of Kepler and Schickard and Pascal became credited with having invented the earliest known mechanical calculator, the Pascaline.


A Pascaline signed by Pascal in 1652 Source: Wikimedia Commons

The first mention of the Rechenuhr was in Michael Gottlieb Hansch’s Kepler biography from 1718, which contained two letters from Schickard in Latin describing his invention. The first was just an announcement that he had made his calculating machine:

Further, I have therefore recently in a mechanical way done what you have done with calculation and constructed a machine out of eleven complete and six truncated wheels, which automatically reckons together given numbers instantly: adds, subtracts, multiplies and divides. You would laugh out loud if you were here and would experience, how the position to the left, if it goes past ten or a hundred, turns entirely by itself or by subtraction takes something away.

The second is a much more detailed description, which however obviously refers to an illustration or diagram and without which is difficult or even impossible to understand.

Schickard’s priority was also noted in the Stuttgarter Zeitschrift für Vermessungswesen in 1899. In the twentieth century Franz Hammer found a sketch amongst Kepler’s papers in the Pulkowo Observatory in St Petersburg that he realised was the missing diagram to the second Schickard letter.


The Rechenuhr sketch from Pulkowow from a letter to Kepler from 24 February 1624

Returning to Württemberg he found a second sketch with explanatory notes in German amongst Schickard’s papers in the Würtemmberger State Library in Stuttgart.


Hammer made his discoveries public at a maths conference in 1957 and said that Schickard’s drawings predated Pascal’s work by twenty years. In the following years Hammer and Bruno von Freytag-Löringhoff built a replica of Schickard’s Rechenuhr based on his diagrams and notes, proving that it could have functioned as Schickard had claimed.

Schickards Rechenmaschine

Schickard’s Rechenuhr. Reconstruction by Bruno Baron von Freytag-Löringhoff and Franz Hammer

Bruno von Freytag-Löringhoff travelled around over the years holding lectures on and demonstrations of his reconstructed Schickard Rechenuhr and thus with time Schickard became acknowledged as the first to invent a mechanical calculator, recognition only coming almost 450 years after his tragic plague death.



Filed under History of Astronomy, History of Computing, History of Mathematics, History of science, History of Technology, Renaissance Science, Uncategorized

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

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

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 Leipzig. 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 Cosmographicus it 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