Johann Ernst Zeiher

Johann Ernst Zeiher (born April 23, 1725 in Weißenfels , † January 7, 1784 in Dresden ) was a German mathematician, mechanic, linguist and optician.

Life

Zeiher, who was involved in the natural sciences from childhood, had already dealt extensively with architecture, artillery, fireworks, mechanics and especially with the construction of optical instruments before he enrolled at the University of Leipzig . Here he devoted himself to mathematics with Abraham Gotthelf Kästner , and had also studied physics and medicine at the University of Erlangen . On a study trip he got to know mining and the smelters in the Ore Mountains.

He returned to Weißenfels, where he first set up his own practice. During this time he perfected his mechanical equipment. He cut glasses, burning mirrors and made optical instruments. He invented various machines and produced models for them before, on the recommendation of his Leipzig sponsor Kästner, he was appointed professor of mechanics at the Petersburg Academy of Sciences in 1756 . Here he had sufficient financial means at his disposal, was able to invent new types of glass and thus manufacture new achromatic telescopes.

On September 17, 1764, he was appointed to the University of Wittenberg , where on October 17, 1764, Johann Daniel Titius gave him the professorship for lower mathematics . In addition to his mathematical lectures, he continued his mechanical work, in particular the manufacture of astronomical and geometric instruments. Magnetic needles and much more emerged from the work in Wittenberg. In 1775, the elector made him an inspector for the Mathematical Salon in Dresden .

As such, he had to prepare physical and mechanical reports for the electoral authorities and to travel to Dresden twice a year during the university holidays. Under his guidance, lightning rods were installed in Electoral Saxony , for example in 1776 at the electoral Dresden palace and the Königstein fortress . Benjamin Gottlieb Laurentius Boden congratulated him on this achievement with the twelve-line poem “Ad Zeiherum Collegam”, which draws on Greek myths.

The Petersburg Academy of Sciences decided in a meeting held on December 22, 1766 unanimously to recall Zeiher under favorable conditions and to transfer him "the Directory of Academic Mechanical Engineering". Zeiher then got in touch with the Electoral Saxon administrator, Prince Xaver of Saxony , and informed him that he would stay in the Electoral Saxon service with the offer with an improved salary. Since he saw himself better able in Saxony to apply "mechanics and mathematics in general to mining, camera and manufacturing" better.

On March 14, 1769, Johann Ernst Zeiher suggested to his faculty that, after the death of the professor of higher mathematics Georg Friedrich Baermann, both mathematical professorships, lower and higher mathematics, should be combined. In addition, he stated that a single teacher could adequately deny the lessons in mathematics, "without fear of the slightest disadvantage for the university". The professorship in lower mathematics that he has held up to now is "the worst of all philosophical professions". The philosophy faculty followed this not new proposal. As a result, Zeiher was granted the professorship of higher mathematics in 1769, but he had to cede his old chair to a new force, to Johann Jakob Ebert .

Zeiher's extensive teaching activities revealed, of course more marginally, technical and practical interest. He held exercises in his “mechanical laboratory”. He had been teaching relevant English language classes since the late 1760s. As a result of these efforts, he wrote a German translation of "Observations on modern gardening" (London 1770) by Thomas Whately under the title "Observations on today's gardening, illustrated by examples" (Leipzig 1771). It gives advice on how to beautify a landscape. Occasional trial offers focused on the teaching of pyrotechnics, optics and the art of marrowing. More often he offered civil and war architecture.

He was also involved in a joint project of the medical and philosophical faculties from 1768 to 1774. Seven volumes from the scientific-mathematical series "Philosophical Transactions" of the London Royal Society were reprinted in English in Wittenberg , with the aim of promoting the spread of science and making the English language, also known as the language of scholars, better known in Germany close. The reprint also found customers in Poland, Russia and Sweden. The focus of the "Transactions" was on original reports on research, which achieved a high level of scientific quality.

In an internal obituary, the faculty praised the special knowledge of its deceased member in mechanics, optics, hydraulics and metallurgy, as well as his particular skill in the manufacture of instruments, apparatus, microscopes, achromatic lenses and burning mirrors.

literature

• Johann Daniel Titius : Life story of Mr. Doct. Johann Ernst Zeiher, former professor of mathematics at the local university. In: Neues Wittenbergher Wochenblatt, vol. 1796, pp. 217–224.
• Heinz Kathe : The Wittenberg Philosophical Faculty 1502–1817 (= Central German Research. Volume 117). Böhlau, Cologne / Weimar / Vienna 2002, ISBN 3-412-04402-4 .
• Walter Friedensburg : History of the University of Wittenberg. Max Niemeyer, Halle (Saale) 1917.
• Fritz Junke: Album Academiae Vitebergensis. Vol. 5 (1710-1812), Halle (Saale) 1966.
• Johann Georg Meusel : Lexicon of the German writers who died from 1750 to 1800. Gerhard Fleischer, Leipzig, 1816. ( Online )
• Friedrich August Weiz : The learned Saxony or directory of those in the Churfürstl. Saxon. and incorporated countries of contemporary writers and their writings. Carl Friederich Schneider publishing house, Leipzig, 1780.

Individual evidence

1. ^ Erik Amburger : Contributions to the history of the German-Russian cultural relations . Kommissionsverlag W. Schmitz, 1961, p. 50

Web links

• Foreign members of the Russian Academy of Sciences since 1724. Johann Ernst Zeiher. Russian Academy of Sciences, accessed November 5, 2015 (Russian).