The Fortieth Parallel Survey is to be credited with contributions to the knowledge of the stratigraphy of the West, the region traversed being remarkably representative of the stratigraphic column, to which was added the paleontologic work of Marsh, Meek, Hall, and Whitfield, while the attempt was made to interpret the sedimentary record in terms of Paleozoic, Mesozoic, and Tertiary geography. King’s plan of survey included large use of topographic mapping with astronomic base and triangulation control and contours based upon barometric elevations. The results were pronounced by an unfriendly critic[102] as “very valuable, especially from a geological point of view,” but unfortunate in being the forerunner of work in which Government geologists “have presumed to arrogate the control of the fundamental operations of a topographic survey.” To the King Survey must be credited the introduction of systematic contour mapping and the use of contour maps for purposes of geology. In two other respects the King Survey contributed largely to future Government work: microscopical petrography in the United States may be said to have begun with the visit of Professor Zirkel to this country as a member of this Survey in 1875, and the report of J. D. Hague on “Mining Industry” was the fitting expression of the emphasis then put on the study of the mineral resources of this newly opened territory, a subject of investigation that was in large part the true basis of King’s project rather than simply “the immediate excuse for the Survey.” An earlier influence in the scientific study of ore deposits had come from Von Richthofen’s investigation of the Comstock Lode in 1865 and his subsequent work with Whitney in California. The incident of King’s relation to the diamond fraud in Arizona in 1872 furnished a precedent for public servants of a later day; he investigated the reported find from scientific interest but exposed it with all the zeal of a publicist and truth lover. In a word, the Fortieth Parallel Survey commands our admiration for its brilliant plan, thoroughgoing work in field and office, and high quality of personnel. [Illustration: J. W. Powell]