1911 Encyclopædia Britannica/Zirkel, Ferdinand
ZIRKEL, FERDINAND (1838- ), German geologist and petrographer, was born at Bonn on the 20th of May 1838. He was educated in his native town, and graduated Ph.D. at the university in 1861. In early years he was engaged in teaching geology and mineralogy in Vienna. He became professor of geology in 1863 in the university of Lemberg, in 1868 at Kiel, and in 1870 professor of mineralogy and geology in the university of Leipzig.
His numerous papers and essays include Geologiscne Skizze von der Westküste Schottlands (1871); Die Struktur der Variolite (1875); Microscopical Petrography (in Report of U.S. Geol. Exploration of 40th Par., vol. vi., 1876); Limurit aus der Vallée de Lesponne (1879); Über den Zirkon (1880). His separate works include Lehrbuch der Petrographie (1866; 2nd ed. 1893, 1894); Die mikroskopische Beschaffenhett der Mineralien und Gesteine (1873).