2 1 4 THE JO URN A L OF GEOL OGY. 



operation until i86i, during which time its labors seemed to 

 have been centered upon systematic county work, leading to 

 the production of special county maps and reports. A table 

 contained in the fifth report of progress shows that, up to the 

 end of i860, field work had been completed in eighty counties, 

 and of these, reports had been made upon thirty-three ; in a 

 considerable number of other counties more or less work had 

 been done. Five of these reports were contained in the Second 

 Annual, and twenty more constitute a report issued in 1873 ; 

 others were probably used in the preparation of the county 

 descriptions of the other reports of 1873 to 1874. In addition to 

 this work, during the period of the first survey, Professor Swal- 

 low made an official report of ninety-three pages on the South- 

 west Branch of the Pacific Railway. 



Reviewing, briefly, this work of the First geological survey, 

 we must recognize as remarkable and excellent the classification 

 of the rocks which are evolved, as well as the general accuracy 

 with which the distribution of the formations was defined, espe- 

 cially when the short time is considered ; avowedly under the 

 control of Hall's New York classification and nomenclature, 

 published in 1843, though undoubtedly assisted, yet not misled 

 by Owen's results. Swallow and his assistants established a table 

 of formations, and outlined a geographical map of the state 

 which remains to this day unchanged in its larger features. 



From i860 to 1870, geological work was nearly at a stand- 

 still in the state. During this period, however. Professor Swallow, 

 as professor of geology at the state university, and various of 

 his assistants in different capacities, extended their observations 

 in the state, and published the results in scientific journals or in 

 the proceedings of scientific societies.^ 



In March, 1870, an act was passed authorizing the Second 

 geological survey. The provisions of this act were in the main 

 similar to those of the'first, with the exception that the Bureau 

 was placed under the control of a board of managers of nine 



' For a Bibliography of the Geology of Missouri, see Bull. No. 2, Mo. Geol. Survey, 

 1890. 



