certificate without passing a Greek examination if he enlisted in the Austrian Army, which he promptly did. Before long, he found himself an artillery lieutenant, principally a forward observer, on the Italian front. He later remarked mordantly that these were among the happiest days of his life. Following his discharge, in the fall of 1919 he entered the University of Graz in electrical engineering and physics, and in 1921 transferred to the University of Munich, where he attended lectures by Arnold Sommerfeld and Arthur Rosenthal. He had lost his entire inheritance, safely invested in government bonds, through the Austrian hyperinflation, and he spent a miserable winter with little food and water frozen in his room each morning.
During this year his interests changed to mathematics, and in the fall of 1922 following Sommerfeld's advice he moved on to the Mathematisches Institut at the University of Göttingen. He began his studies with the new director of the Institut, Richard Courant, who became a very close friend, also took courses with Edmund Landau and Emmy Noether, and in 1923 became an assistant at the Institut and special assistant to Courant in 1924. Significantly, he was also in charge of the Lesezimmer, the library. During 1924-25 he was at the University of Copenhagen with Harald Bohr, another close friend, with whom he published in 1926 a paper on differential equations with almost periodic functions, one of Bohr's specialties, which turned out to be his only paper in pure mathematics.
For again, Neugebauer's interests had changed, this time to the history of Egyptian mathematics for which he studied Egyptian with Hermann Kees and Kurt Sethe. His thesis Die Grundlagen der ägyptischen Bruchrechnung (Springer, 1926), was principally an analysis of the table in the Rhind Papyrus for the expression of fractions of the form 2/n as a sum of different unit fractions, fractions with the numerator 1,