Johann Friedrich Hennert

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Johann Friedrich Hennert

Johann Friedrich Hennert (born October 19, 1733 in Berlin , † March 30, 1813 in Utrecht ) was a German mathematician and astronomer in Utrecht.

Life

The son of the court counselor at the Supreme Court of Auditors in Berlin Friedrich Hennert († before June 12, 1771) evidently did not grow up in a poor family and was the older brother of Karl Wilhelm Hennert . He received his first scientific training at the Joachimsthal Gymnasium , which he attended under the rectorate of Johann Philipp Heinius (1688–1775). Although his father would have liked to have devoted himself to law, he developed a preference for the mathematical sciences. From 1747 he found a teacher in Johann Georg Sulzer who was able to bring him closer to the mathematical knowledge of his time. It should also have been the one who brought him into contact with Leonhard Euler , who worked at the Royal Prussian Academy of Sciences in Berlin. He liked to remember this teacher who had a lasting effect on him.

In 1755 he made a journey that took him through various European locations. For example, his matriculation on September 11, 1755 at the University of Leiden can be proven. However, his destination was Paris, where he lived for two years in the house of Joseph-Nicolas Delisle . At that time he also met the professor of mathematical physics Pierre Charles Lemonnier . Around 1757 he went to The Hague , where he gave lessons in the field of philosophical sciences and in 1758 published his first work, Traite sur les Thermometres . On November 1, 1759, we find him again at the Leiden University, where he worked as a repetitionist and, with the permission of the professors , opened a mathematics school in Leiden . Since Johann Castillon had received an appointment to Berlin in 1763, a suitable successor was sought in Utrecht. Therefore, on January 2, 1764, Hennert was appointed associate professor of philosophy, mathematics and astronomy by the curators of the University of Utrecht.

In order to have the necessary academic degree, he had presented the treatise dissertatione et sportulis , whereupon he was appointed an honorary doctor of the philosophical sciences by Johann David Hahn on February 3 of the same year . He began the task assigned to him on February 6, 1764 with the speech de ingenio Mathematici , was appointed full professor of philosophy, mathematics and astronomy on October 7, 1765 and took over the office on November 18, 1765 with the speech de matheseos studio cum solida educatione conjungendeo . In Utrecht he had also taken part in the organizational tasks of the university and held the rectorate of the Alma Mater in 1768/69 and 1781/82 . Among other was Jan Hendrik van Swinden one of his most important students. During that time he had also received offers in Berlin and at the University of Halle, but he turned them down.

When unrest broke out in the Batavian Republic in 1787 , he resigned his professorship in Utrecht on March 6, 1787 and went to Hanover . After the unrest ended, efforts were made to move Hennert to Utrecht. Here he took over his office again on August 31, 1788 and was confirmed by the university's curators on September 1, 1788. After that, in 1794/95 he again took part in the university's organizational tasks as rector of the alma mater. In 1802 Hennert suffered an inflammation of the left eye and subsequently went blind. Therefore, he asked for his discharge from college, was retired on December 10, 1804 and spent his old age in retirement. His successor in the field of mathematical and astronomical sciences in Utrecht was his former student Jan Frederik van Beeck .

Hennert was married to the poet Petronella Johanna de Timmerman (born February 4, 1724 in Middelburg; † May 1, 1786 in Utrecht). His second marriage was with Constantia Agneta de Reder.

literature

Web links

Individual evidence

  1. ^ Obituary in Algemene const- en letterbode 1813
  2. ↑ cf. File: Procuratie 12-06-1771 (Dutch)
  3. ↑ Life report at KNAW (Dutch) (PDF; 420 kB)
  4. ↑ Album Studiosorum Academiae Lugduno Batavae MDLXXV-MDCCLXXV. Martinum Nijhoff, The Hag, 1875, Sp. 1050
  5. ↑ Album Studiosorum Academiae Lugduno Batavae MDLXXV-MDCCLXXV. Martinum Nijhoff, The Hag, 1875, Sp. 1065
  6. ↑ Frans Ketner: Album Promotum qui inde from anno MDCXXXVI usque ad annum MDCCCXV in Academia Rheno-Trajectina gradum doctoratus adepti sunt, Societas cui nomen "Provinciaal Utrechtsch Genootschap van Kunsten en Wetenschappen" componendum edendicesque délendumque trainee curavit, atqueondiae academiae obtulite. Boeckhoff Verlag, Utrecht, 1936, p. 172
  7. ↑ GJ Loncq CJZ: Historic Schets the Utrechtsche Hoogeschool dead hare Verheffing in 1815. JL Beijers and J. van Boekhoven, Utrecht, 1886, p 235
  8. ↑ life data with picture (Dutch)
  9. ^ Certificate of death Utrecht (Dutch)
personal data
SURNAME Hennert, Johann Friedrich
BRIEF DESCRIPTION German mathematician and astronomer
DATE OF BIRTH October 19, 1733
PLACE OF BIRTH Berlin
DATE OF DEATH March 30, 1813
Place of death Utrecht