Born in Berlin. Student of Mathematics under Swiss Mathematician Leonhard Euler (1707-1783) and French Mathematician and Astronomer Joseph Nicolas Delisle (1688-1768). Professor of Philosophy, Mathematics and Astronomy at the University of Utrecht (1764-?) From the 1780s he also offered public lectures on the course of rivers. 1 He authored Dissertations physiques et mathematiques (1778)
Life with Boswell
Boswell went to Hennert's inaugural lecture, De Ingenio Mathematici, at Utrecht on Frebruary 6, 1764, describing him as "lively and eloquent".