With his degree, Fritz returned to Breslau to work at his father's chemical business. They did not get along well. Through Siegfried's connections, Fritz was assigned a series of practical apprenticeships in different chemical companies, to gain experience. These included Grünwald and Company (a Budapest distillers), an Austrian ammonia-sodium factory, and the Feldmühle paper and cellulose works. Haber realized, based on these experiences, that he needed to learn more about technical processes, and persuaded his father to let him spend a semester at Polytechnic College in Zürich (now the Swiss Federal Institute of Technology), studying with Georg Lunge. In fall of 1892, Haber returned again to Breslau to work in his father's company, but the two men continued to clash and Siegfried finally accepted that they could not work well together.