The New International Encyclopædia/Iddings, Joseph Paxson

ID′DINGS, Joseph Paxson (1857—). An American geologist, born in Baltimore, Md. He graduated at the Sheffield Scientific School of Yale in 1877, was a graduate student and assistant in mechanical drawing and surveying there until 1878, and continued his studies in geology and microscopic petrography at Columbia University and Heidelberg. From 1880 until 1892 he was in the service of the United States Geological Survey, to which he returned in 1895. In 1892 he became assistant professor, and in 1895 professor, of petrology at the University of Chicago. His Government explorations were described in many reports and contributions to scientific journals. Among his more important writings are: The Nature and Origin of Lithophysæ and the Lamination of Acid Lavas (1887), reprinted from the American Journal of Science; On the Development of Crystallization in the Igneous Rocks of Washoe, Nev. (1885), with Arnold Hague; and The Origin of Igneous Rocks (1892), in the Bulletin of the Washington Philosophical Society.