**Wenceslaus Karsten** was a German mathematician who wrote about the logarithms of negative and complex numbers.

- Having lost their home and all their possessions, the Karsten's moved to accommodation in Burg Stargard, just south of Neubrandenburg.
- Johann Christopher then tried to rebuild the pharmacy in Neubrandenburg but in 1741 he too went to live in Güstrow where he became a notary and ran a small farm.
- Although Karsten received his education in Güstrow, certainly at first at the Fürstliche cathedral school, it was a schooling which aimed to teach languages and very little attention was given to mathematics or natural science.
- Later however, beginning in 1748, when he showed great mathematical potential, Karsten was given private instruction in mathematics.
- Karsten went to Rostock to study for his doctorate which was awarded in February 1755 for his thesis Algebra ejosque differentia ab Arithmetica Respondente Ⓣ(Algebra of differences from an arithmetical point of view), and he was appointed there as a privatdozent at Easter.
- Aepinus had not yet left Rostock when Karsten took up his post and was able to advise him about teaching.
- He also introduced Karsten to Euler and the two exchanged a series of letters (38 in all, of which 23 were written by Karsten) between 1758 and 1765.
- Karsten began publishing work at Rostock: De affectionibus, quae omnis generis functionum, praecipue si tres vel adeo quatour involvant variabiles, differentialibus competunt, si eorum integrale sit possibile Ⓣ(Affecting functions of every kind, especially if they involve two, or even three variables, their differentials if they exist, if it is possible for them to be integrated) (1756), Elementa matheseos universalis Ⓣ(Elements of universal mathematics) (1756), Beweis, dass der Algorithmus speciosus keine widersinnigen Rechnungsregeln enthalte Ⓣ(Proof that the false-position algorithm contains no incorrect calculating rules) (1757), and Praelectiones matheseos theoreticae elementarisⓉ(Readings in elementary theoretical mathematics) (1758).
- Realising that his chances of a professorial appointment at Rostock were small, Karsten applied for various positions.
- Karsten was appointed as professor at the University of Rostock in 1758 but the university suffered problems a couple of years later as a result of a dispute between the city of Rostock and Duke Friedrich of Mecklenburg.
- Karsten was transferred to Bützow where he was rector of the university for a semester in 1765 and again in 1768-69.
- This meant that Karsten had to teach in a university in which, certainly at first, there was no library and not even lecture rooms.
- Karsten had to teach classes of students in his own home.
- In 1765 Karsten was involved in the publication of Euler's Theoria motus corporum rigidorum Ⓣ(Theory of the motion of rigid bodies).
- Karsten was appointed to the University of Halle in 1778 to fill the chair which was left vacant on the death of Segner in October of the previous year.
- Karsten filled this position until his death in 1787.

Born 15 December 1732, Neubrandenburg, Mecklenburg-Strelitz, Germany. Died 17 April 1787, Halle, Germany.

View full biography at MacTutor

Origin Germany

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive