**Arthur Hirsch**attended both primary and secondary school in Königsberg, and completed his school education in 1882. Hirsch studied mathematics, physics and philosophy in his hometown and in Berlin. Among his teachers in Königsberg were Hilbert and his future colleague Hurwitz, who remarked that Hirsch was 'one of his most talented students in Königsberg' [2]. In 1892 he received his doctorate from the University of Königsberg for his thesis

*Zur Theorie der linearen Differentialgleichungen mit rationalem Integral*.

A year later he moved to Zürich where he habilitated as Privatdozent for mathematics at the Polytechnic, upon the recommendation of Hurwitz. He also became Hurwitz's assistant, and took over some of his lectures when Hurwitz had to reduce his workload due to illness after 1900. Hirsch became Titularprofessor in 1897, and in 1903 he was appointed to an ordinary professorship, succeeding Minkowski in his chair for higher mathematics [3]. He taught 'differential equations, variational calculus and hypergeometric integrals of higher order' [5], mainly to future engineers, 'but he did not leave too many marks' [5]. Hirsch acted as co-advisor and second examiner for a number of PhD theses between 1916 and 1926, but none of the PhD candidates became influential in mathematics. He was Deputy Head of the Department for Mathematics and Physics Teachers for more than a decade. In 1909 Hirsch was listed as Deputy Head in the School Board minutes for the first time; he was re-elected every other year until 1921. After that the minutes do not contain the list of Department Heads anymore [6]. Pólya (who went to Zürich in 1914) recalls that he also was 'Department Head at the ETH in the first years I was there' [4].

Hirsch published a few papers in *Mathematische Annalen*, primarily on differential equations and integrals. Examples of his publications are *Die Existenzbedingungen des verallgemeinerten kinetischen Potentials* (1898) and *Über bilineare Relationen zwischen hypergeometrischen Integralen höherer Ordnung* (1899).

Hirsch was a member of the Swiss Mathematical Society; he also attended some of the German Mathematical Society's annual meetings. Unlike many of his German colleagues who stayed in Zürich for the rest of their lives, it seems that he did not acquire Swiss citizenship.

Hirsch joined the organising committee of the first International Congress of Mathematicians in December 1896. At the meeting on 21 January 1897 Hurwitz and Rudio suggested that Hirsch join the reception committee (alongside Burkhardt and Gubler), partly in order to help deal with the congress publications. As assistant German-speaking secretary he was also involved in finalising the congress programme (with Geiser, Franel and Dumas). During the congress he acted as Rudio's personal secretary. Like his colleagues Dumas and Franel, Hirsch was on the organising committee for the 1932 ICM in Zürich, but did not give a talk during the congress.

Arthur Hirsch retired in 1936.

**Article by:** Stefanie Eminger, University of St Andrews