German mathematician; born March 26, 1859, at Hildesheim; studied at Munich, Berlin, and Leipsic. In 1882 he became privat-docent at Göttingen; in 1884 he was appointed assistant professor at the University of Königsberg; in 1892, professor at the Polytechnicum of Zurich. He has contributed articles to the mathematical periodicals, especially to the "Mathematische Annalen," "Acta Mathematica," and the "Nachrichten" of the Gesellschaft der Wissenschaften zu Göttingen, of which society he was elected a corresponding member in 1892.