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Missouri. Appendices A, B, C and D contain much statistical and other matter of subordinate interest.

The survey was discontinued after the year 1874, and most of its working material was transferred to the state School of Mines at Rolla, of which the president, Dr. Charles P. Williams, was made acting state geologist, with a nominal appropriation. Little field work seems to have been carried on under Dr. Williams, and, after the year 1876, no further support was extended to the work by the state. One report was prepared by Dr. Williams, which consists of a small octavo of 117 pages. It contains a chapter on the "Mineralogy and General Metallurgy of Lead," one on the "Zinc Industry of Missouri," one on the "Iron Industry," and one on "Shannon County"; in the appendices are given a few statistics of lead and zinc, and a "Note on the Occurrence of Gold in Northwestern Missouri."

Reviewing the results of the Second geological survey, its contribution to our knowledge of the geology of the state consisted principally: (1) of Pumpelly's observations, too soon interrupted, upon the crystalline rocks, whose work threw much new light upon their nature and relations, though the report has left us in some doubt as to whether he considered the whole mass of the porphyries metamorphosed clastics, or whether he meant this to apply only to the Pilot Knob beds; (2) of Broadhead's detailed stratigraphic results in the Coal Measures which placed on record many new and valuable sections, added much concerning their correlation, and demonstrated the thickness of this formation to be much greater than had been formerly believed; (3) of Schmidt's report on the iron ores and lead and zinc deposits, especially strong in its treatment of the mineralogy, but deficient in its interpretations of structure, and lacking in suggestions as to origin and processes. The classification of the clastic rocks remained substantially the same as tabulated by Swallow and Shumard, the principal changes displayed in the chart opposite page 18 of the report of 1873-74 being in the subdivisions of the Lower Carboniferous; in the transference of the Chouteau, Vermicular and Lithographic stages to this series; and