In 1870 Weber moved to Karlsruhe, where he worked as assistant to Gustav Wiedemann (1826-1899) at the Polytechnic School. A year later he became Helmholtz's assistant in Berlin, and in 1874 he moved to Hohenheim, where he taught physics and mathematics at the Royal Academy of Württemberg. A year later he was offered a professorship at the Polytechnic in Zürich :
When he noticed a short elderly gentleman among his students [at the Academy], he did not pay much attention to him; however he was quite surprised when, directly after the lecture, that gentleman asked him whether he would like to accept a professorship in Zürich. It was Kappeler, the former president of the School Board, who had attended the lecture incognito. When appointing new members of staff, Kappeler wanted to consider only his direct personal opinion.At the Polytechnic Weber mainly lectured on technical physics. He also supervised more than forty-three doctoral students; quite a few of them became professors at universities across Europe . His most famous student, however, was Einstein, who often worked in Weber's laboratories. But despite being a 'lecturer beyond comparison' , he also had his shortcomings: As a 'typical representative of classical physics'  he did not teach Maxwell's theories, nor 'the foundations of physics, as he did not teach theoretical or mathematical physics' . Therefore, Einstein often skived his lectures, on which Weber commented: "You are a clever boy, Einstein, a very clever boy indeed. But you have a great shortcoming: you don't listen to anyone!" . However, 'he and his institute at least helped further sensitise Einstein to the importance of measurement for testing theory and for finding the best fit between theory and empirical reality' .
In fact, as 'a pioneer in electrical engineering in Switzerland and Germany'  he helped to establish a system of units of measurement, together with physicists such as Lord Rayleigh, Silvanus Thompson, Friedrich Kohlrausch, Eletuhère Mascart, and Lord Kelvin. The latter was a good friend of Weber's. Among other things he experimented with alternating and direct current, with heat conduction, with blackbody radiation and with specific heat.
Among Weber's publications, Die spezifische Wärme der Elemente Kohlenstoff, Bor und Silizium Ⓣ (1874), Der absolute Wert der Siemensschen Quecksilbereinheit Ⓣ (1884), and Die Entwicklung der Lichtemission glühender fester Körper Ⓣ (1887) are of particular importance. His 1874 paper inspired Einstein to develop the Einstein solid in 1907.
Weber was also interested in meteorology. He joined the Federal Meteorological Commission in 1881; in 1902 he became vice-president and eight years later president. However, Weber's most important achievement was the physics institute at the Polytechnic, which opened in 1890. The previous physics laboratories were too small and the equipment was out of date. For several years Weber tried to get the Swiss government's permission to build at least an extension of the existing institute, though he really wanted laboratories that could cater for any future developments in (electrical) engineering. It was only when Werner Siemens declared his support for "Weber's vision [which] proved decisive in winning the backing of Kappeler and Geiser"  that the government gave in and provided the necessary funds. Weber's ideas turned out to be highly successful: for a number of years the institute was the finest of its kind in the world and thus added to the Polytechnic's growing reputation. It was "especially designed to train electrical engineers or applied physicists [which] was what the Swiss wanted their tax money spent on" .
Weber joined the organising committee of the first International Congress of Mathematicians at the preliminary meeting in July 1896. He did not attend all the committee meetings though and did not get assigned any particular jobs (based on the minutes). He was the only physicist and only one of two non-mathematicians on the committee.
Weber married Anna Hochstetter in 1875. The couple had three daughters and five sons, all of which became academics: Oskar: chemist; Friedrich: geologist; Ernst: civil engineer and astronomer; Helmut and Richard: physicians .
Article by: Stefanie Eminger, University of St Andrews