The New International Encyclopædia/Zirkel, Ferdinand

ZIRKEL, tsēr'kel, (1838&mdash;). A German mineralogist, born at Bonn. He was at first interested in mining, visited Iceland in company with Preyer in 1860, and after being employed for two years in the Geological Institution at Vienna, became professor, successively at the universities of Lemberg (1863), Kiel (1868), and Leipzig (1870), where he was also made director of the Mineralogical Museum. He traveled for study in France, Italy, and Scotland; came to America in 1874 to examine the great collections of minerals made during the exploration of the fortieth degree of latitude, and in 1894-95 pursued scientific investigations in Ceylon and India. His more extensive writings include: Reise nach Island im Sommer 1860 (with Preyer, 1862); Lehrbuch der Petrographie (1866, 2d ed. 1893-95); Die mikroskopische Beschaffenheit der Mineralien und Gesteine (1873); &ldquo;Microscopical Petrography,&rdquo; in Report of the United States Geological Exploration of the Fortieth Parallel (1876); and Ueber Urausscheidungen rheinischer Basalte (1893). After the death of Naumann he edited the new issues of his Elemente der Mineralogie (14th ed. 1901).