Christian August Hausen (1693–1743) was a German mathematician who is known for his research on electricity.
Hausen studied mathematics at the University of Wittenberg and received his master’s degree in 1712. He became an extraordinary professor of mathematics at the University of Leipzig at the age of 21 and later (1726) became an ordinary professor.
Hausen also researched electrical phenomena, using a triboelectric generator. In the introduction to his book on this subject, Novi profectus in historia electricitatis, published posthumously, Hausen states that he started these experiments shortly before his death. Hausen’s generator was similar to earlier generators, such as that of Francis Hauksbee. It consisted of a glass globe rotated by a cord and a large wheel. An assistant rubbed the globe with his hand to produce static electricity. Hausen’s book describes his generator and sets forth a theory of electricity in which electrification is a consequence of the production of vortices in a universal electrical fluid.
Abraham Gotthelf Kästner (27 September 1719 – 20 June 1800) was a German mathematician and epigrammatist.
He was known in his professional life for writing textbooks and compiling encyclopedias rather than for original research. Georg Christoph Lichtenberg was one of his doctoral students, and admired the man greatly. He became most well known for his epigrammatic poems. The crater Kästner on the Moon is named after him.
Kästner studied law, philosophy, physics, mathematics and metaphysics in Leipzig from 1731, and was appointed a Notary in 1733. He gained his Habilitation from the University of Leipzig in 1739, and lectured there in mathematics, philosophy, logic and law, becoming an associate professor in 1746. In 1751 he was elected a member of the Royal Swedish Academy of Sciences. In 1756 he took up a position as full professor of natural philosophy and geometry at the University of Göttingen. In 1763, succeeding Tobias Mayer, he became director of the observatory as well. One of his doctoral students was the physicist and aphorist Georg Christoph Lichtenberg, who became a colleague of his at Göttingen. Other notable doctoral students were Johann Christian Polycarp Erxleben, Johann Pfaff (doctoral adviser of Carl Friedrich Gauss), Johann Tobias Mayer, Heinrich Wilhelm Brandes, Farkas Bolyai (father of János Bolyai), and Georg Klügel. Kästner died in 1800 in Göttingen.