Person: Kästner, Abraham
Abraham Kästner was a German mathematician who compiled encyclopaedias and wrote textbooks. He taught Gauss.
Mathematical Profile (Excerpt):
 Kästner wrote his habilitation thesis at the University of Leipzig, and was awarded the qualification which allowed him to teach there in 1739.
 Kästner is not famed for original research but rather he was involved in compiling encyclopedias and in writing textbooks.
 However Kästner was quite unenthusiastic about logic, but this is not surprising for a mathematician of this period who was interested in geometry.
 Perhaps the most important feature of Kästner's contributions was his interest in the parallel postulate which indirectly influenced Bolyai and Lobachevsky too.
 Kästner, in spite of his rather great inclination for Euclid's Elements, based his version of the axiomatics of geometry in his Kompendium on other principles (e.g., on motions) and attempted both to seize on other fundamental properties (continuity, ordering) and to determine the selection of the parallel axiom as a foundation.
Born 27 September 1719, Leipzig, Germany. Died 20 June 1800, Göttingen, Germany.
View full biography at MacTutor
Tags relevant for this person:
Astronomy, Origin Germany
Thank you to the contributors under CC BYSA 4.0!
 Github:

 nonGithub:
 @JJO'Connor
 @EFRobertson
References
Adapted from other CC BYSA 4.0 Sources:
 O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive