Born: 1546 in Breslau, now Wrocław, Poland
Died: 9 January 1586 in Vienna, Austria

The date of Paul Wittich's birth is unknown. The 1546 date which we give was computed by Gingerich [4] based on Wittich's known matriculation date at university and the average age at which students of that period matriculated. Little is known of his family background [3]:-

Well born, and probably well off, Wittich was an enigmatic character whose roots remain mostly obscure.

However, certain information from letters written at the time show at least that his family included scholars in contact with the leading mathematicians and astronomers of the day [3]:-

But a hitherto unknown letter from Andreas Dudith to Johannes Praetorius, written soon after Wittich's death, suggests that Wittich was already associated by family ties to the Wittenberg astronomical tradition:

"Wittich said that the Epitome of Copernicus was written by the author himself; he received it from his uncle, a well-known physician and mathematician of this city, named Balthasar [Sartorius] whose many letters to Rheticus you were able to see at Rheticus' house. I am surprised that Rheticus did not show us this Epitome, which the doctor [i.e. Sartorius] is likely to have received from him; the book is not printed but is written in Wittich's hand; it is in quarto; it has 14 folios whose gatherings, as they call them, make four."

The book described is clearly Copernicus' 'Commentariolus', the very first formulation of his heliocentric theory, and the setting shows that Wittich's astronomical connections reached through his uncle to Rheticus himself. In addition, Rheticus, who had been Copernicus' only disciple, corresponded with a Johannes Wittich in Wroclaw, who may have been another of Paul's relatives.

The first precise date we know for Wittich is that he matriculated at University of Leipzig in the summer of 1563. He then matriculated at Wittenberg in June 1566. No record exists of any degrees awarded to him by either of these universities. If Wittich was born in 1546 then he was born in the same year as Tycho Brahe. Certainly Tycho was a student at Wittenberg at the same time as Wittich but later remarked that he scarcely remembered him. This, of course, may relate to the fact that Tycho later became extremely antagonistic towards Wittich for reasons which we shall explain below. The authors of [3] write:-

We now know that Wittich became a kind of itinerant humanistic tutor to men who valued and practiced astronomy in a variety of contexts.

However, this interpretation is doubted by Richard S Westfall who writes "frankly I did not see the evidence on which this assertion was based." Certainly Wittich travelled widely after his time in Leipzig and Wittenberg [3]:-

His routes fan out from his home town of Wroclaw west to the Silesian town of Görlitz; then, a hundred miles beyond it, to the major university centres of Leipzig and Wittenberg ...; then, south to the great Hapsburg Court at Prague; later the academy of Altdorf, near Nuremberg; and finally, to yet another university town, Frankfurt an der Oder.

Wittich matriculated at Frankfurt an der Oder in 1576 and there he met John Craig, from Edinburgh, who was dean at Frankfurt an der Oder for several years before returning to Edinburgh. Let us remark that Craig then became personal physician to James VI of Scotland (later James I after the union of the crowns of England and Scotland). The connection with Craig is interesting, particularly in the light of a comment by the historian Anthony à Wood (1632-1695) that Napier got the idea for logarithms from a method brought back from the Continent by John Craig. It is certainly possible that the method referred to by Wood is one invented by Wittich since we know that Wittich found how to replace multiplication and division with addition and subtraction using the rules for sines and cosines of the sums and differences of angles. In one of his copies of De revolutionibus, Wittich used the blank space at the end of a chapter to write out an example of his method, known as prosthaphaeresis [2]:-

And this was precisely one of the pages that John Craig had transcribed into his copy of 'De revolutionibus' when he was being tutored by Wittich in Frankfurt an der Oder in 1576. In turn he took his annotated copy with him when he returned to Edinburgh, and he surely must have shown it to Napier who was living in a castle in the area.

By October 1579 he was back in Wroclaw where he worked with Andreas Dudith. They observed the partial eclipse of the sun on 22 October 1579 and a total eclipse of the moon on 31 January 1580. Dudith wrote in a letter to a friend:-

Wittich allows neither reason nor advice, neither "prayers nor prizes" (as you say), to dissuade him from his enthusiasm for travelling. In his very pleasant company for a few days, I have felt myself enflamed for mathematical studies ...

Later Dudith wrote, again in a letter:-

I am making great efforts so that I might not only retain Wittich in this city, but that I might keep him in my house.

Certainly Dudith did not succeed in persuading Wittich to give up his enthusiasm for travelling for in the summer of 1580, taking with him a letter of introduction from Thaddaeus Hagecius, he went to visit Tycho on the island of Hveen (called today Hven or Ven) in Copenhagen Sound where Tycho had his observatory Uraniborg. Hagecius had been professor of mathematics at the Charles University of Prague and was in frequent scientific correspondence with Tycho. The visit to Uraniborg must have been an exciting one for Wittich [2]:-

Tycho held nothing back as he explained the novel star-sights and scales on his quadrants, sextants, and armillary spheres. They toured the library with its thousands of books and its giant celestial globe, and they swapped notes on their ingenious trigonometrical methods. And the quest [Wittich] showed his host [Tycho] the technical underpinnings of his cosmological speculations ... The idea of preserving some of the Copernican details, but with the Earth as the fixed centre, must have greatly intrigued Tycho.

Pierre Kerszberg explains the relation between Wittich's planetary theory and that proposed by Tycho:-

By the end of the 1570s, Tycho had found an orbit for the comet of 1577 that tallied well with the older view that Mercury and Venus circled around the Sun. In 1580, however, he was exposed to the rich commentaries of Copernicus that Wittich had brought with him during a four-month visit at the isle of Hven, the site of Tycho's observatory. Wittich's diagrams are semigeoheliocentric, and therefore retain the solid crystalline spheres, only because they fail to solve completely the problem of the possible collision between the Sun and a planet such as Mars. Tycho published his own fully geoheliocentric system in 1588, but then there followed a bitter dispute of priority and discovery with N R Ursus, who had published shortly thereafter a system containing striking similarities with Tycho's. In the process, Tycho accused Wittich of divulging secrets, which suggests that some communication between Ursus and Wittich could conceivably have occurred.

Now the dispute between Tycho and Wittich was based on more than who had invented the planetary theory. Wittich left Uraniborg after spending four months there claiming (perhaps correctly or perhaps as an excuse) that he had to return to Wroclaw to deal with an inheritance from a rich uncle. On Saturday 29 October 1580 Tycho wrote the following inscription in Latin on the title page of Peter Apian's Astronomicum Caesareum, then gave the book to Wittich:

To Paul Wittich of Wratislava, friend and fellow lover of mathematics.

Clearly, despite Tycho's appreciation of Wittich at this time, Wittich had become tired of Tycho; he promised to return but never did. Back in Wroclaw he joined discussions with Henry Savile, who was visiting, about Ptolemy and Copernicus.

By 1584 Wittich was in Kassel working with Bürgi helping improve the design of the instruments he was making for the Observatory of Wihelm of Hesse in Kassel. Wihelm of Hesse was Tycho's great astronomy rival and Wittich now passed on Tycho's secrets regarding star-sights and scales. Wilhelm was delighted and gave Wittich a gold chain in return for his suggestions about improving his instruments. Tycho, on the other hand, was furious and had his revenge when he published the first volume of his correspondence where he strongly asserted that ideas in the planetary theory were entirely his own, and scarcely mentioned Wittich despite the fact that his planetary theory originated with him. He also claimed to have discovered the method of prosthaphaeresis which Wittich had shown him.

1. Adam Mosley, Paul Wittich, in Thomas Hockey (ed.) Biographical Encyclopedia of Astronomers (2007), 1234-1235.

Books:

1. O Gingerich, The book nobody read : Chasing the Revolutions of Nicolaus Copernicus (Arrow Books, London, 2004).
2. O Gingerich and R Westman, The Wittich Connection : Conflict and Priority in Late Sixteenth-Century Cosmology, Transactions of the American Philosophical Society 78 (7) (1988).

Articles:

1. O Gingerich and M Gingerich, Matriculation ages in Sixteenth-Century Wittenberg, History of Universities 6 (1987), 135-137.
2. O Gingerich, Wittich's annotations of Copernicus, Papers of the Bibliographic Society of America 76 (1982), 473-478.
3. N Jardine, How to appropriate a world system. Review of O Gingerich and R S Westman, The Wittich connection, J. Hist. Astronom. 21 (4) (1990), 353-358.