Page:Popular Science Monthly Volume 53.djvu/21

 theme of this communication, is also important in establishing methods for determining similar great changes of land and ocean in other regions in late geological times.

.—The methods of inquiry belong to geomorphy, or the study of land forms. Geomorphy is the outgrowth of topography, which was made a science fifty or sixty years ago by Prof. J. P. Lesley and his coworkers. Its birth is graphically described by the author himself: “That the European Jura … had to wait for its elucidation until the American Appalachians had been mapped may seem strange, but it admits of easy explanation. In Pennsylvania, paleontology and detailed local stratigraphy were impossible; we were untrained in both, … The country was no ground for mineralogy; no rare and curious minerals exist in it; it is a waste of sand, mud, iron, and limestone strata of various textures and color in endless repetition; to know one was to know all; to know it here was to know it everywhere. Nothing remained to study but dynamic forms; and these so numerous, so grand, so variously grouped that they excited our perpetual enthusiasm, and led to infinite research; they supplied the place of fossil forms, of forms of crystals, and of variations of mineral elements; they were a world of the exhibition of the natural forces by itself, and as such we took possession of it and settled in it as our fathers did in the valleys themselves, and thus became not mineralogists, not miners, not learned in fossils, not geologists in the full sense of the term, but topographers; and topography became a science, and was returned to Europe and presented to geology there as an American invention. The passion with which we all studied it is inconceivable, the details into which it led us were infinite. … They trained us to that fertility of fancy which precedes the ripening of the constructive or geometric faculty, made to act upon the more difficult problems of geology; while its generalizations were so vast … that customary European local research … seemed tedious. … The moment, therefore, that one of us beheld the ranges of the Jura, with their combs and offsets, their vast escarpments, and far-glittering white gaps, he was at home among friends, where geologists, born among them, felt that they were strangers. For the valleys of the Jura were filled with later formations full of fossils, which the Appalachian valleys never are. There much is hidden, here all is told. Fossils themselves in the Jura distracted study from the topography.”

Geomorphy, like its antecedent, the science of topography, is