404 



GEOLOGICAL SURVEY OF THE UNITED STATES. 



he was called upon to supervise that his per- 

 sonal studies were greatly hampered. The 

 junior assistants, exempt from the cares of ad- 

 ministration, were able to push their special 

 investigations far in advance of the comple- 

 mentary work undertaken by their chiefs and 

 senior colleagues. The talents and acquire- 

 ments that rendered the work of an individ- 

 ual most desirable, led, by qualifying him to 

 direct the work of others, to a great dimi- 

 nution in his personal accomplishment. The 

 original subdivision of the work by geographic 

 areas has therefore been in large part aban- 

 doned, and for it there has gradually been sub- 

 stituted a system in which the primary basis 

 of subdivision is the nature of the work to be 

 performed, and in which the body of the work 

 placed under the direction of one assistant is 

 not so large that his administrative duties make 

 serious encroachments upon his time. At the 

 present time the survey has the following or- 

 ganization : 



In the department of general geology eight 

 independent investigations are in progress. 

 Each of these is in charge of a geologist, and, 

 with a single exception, each geologist super- 

 vises the work of a corps of assistant geolo- 

 gists. Prof. T. 0. Chamberlin is at the head 

 of the division of glacial geology, having for 

 his field all those States east of the Rocky 

 mountains in which the vestiges of ancient 

 glaciers are found (see map). Two divisions 

 are organized for the investigation of the met- 

 amorphic crystalline schists. The first has its 

 field in the eastern portion of the United States 

 known as the Appalachian region, and is in 

 charge of Prof. Raphael Pumpelly. To the 

 second, under Prof. Roland D. Irving, is as- 

 signed the Lake Superior district. The divis- 

 ion of volcanic geology and seismology is in 

 charge of Capt. 0. E. Button, and his principal 

 field is in the States and Territories bordering 

 the Pacific Ocean. Mr. Arnold Hague is con- 

 ducting an investigation of the thermal springs 

 of the Yellowstone region and of the general 

 geology of the National Park. The general 

 geology of the Appalachian region, with the 

 exception of the areas of crystalline rocks, is 

 in charge of Mr. G. K. Gilbert. Work on the 

 geology of the region of the sources of the 

 Mississippi is conducted by Dr. F. V. Hayden ; 

 and Mr. W. J. McGee is studying the geologic 

 history of the vicinity of Washington City. 



In the department of economic geology there 

 are three independent corps. The first, under 

 Mr. G. F. Becker, has its field on the Pacific 

 coast, and is at present giving special attention 

 to the quicksilver deposits, the second, under 

 the direction of Mr. S. F. Emmons, has its field 

 in the Rocky mountains, and is occupied with 

 the study of deposits of gold, silver, and coal, 

 and with the subject of artesian wells. The 

 third, in charge of Mr. Albert Williams, Jr., 

 collates annually the statistics of the produc- 

 tion' in the United States of the non-precious 

 metals and other economic minerals. 



Of the affiliated sciences whose results ar 

 tributary and essential to geologic investigc 

 tion, paleontology receives most attentior 

 The work is organized in five divisions, th 

 basis of organization being primarily biologic 

 All the work on fossil vertebrates is in charg 

 of Prof. 0. 0. Marsh, and all on fossil plant 

 in charge of Mr. Lester F. Ward. The stud 

 of invertebrate fossils is subdivided on th 

 basis of geologic chronology. Shells of Pt 

 leozoic age are assigned to Mr. C. D. "Wa! 

 cott, those of the Mesozoic and Cenozoic t 

 Dr. 0. A. White, and those of the Quaternar 

 to Mr. William H. Dall. The subject of litl. 

 ology engages the attention of a considerabl 

 number of specialists, but these are not segn 

 gated in a corps. They are attached to varior 

 divisions of general and economic geology 

 Similarly, there are chemists attached to tb 

 Pacific and Rocky mountain divisions of ecf 

 nomic geology ; but there is also an indepenc 

 ent division of chemistry, and this is in charg 

 of Prof. F. W. Clarke. A large share of iij 

 work consists in the execution of analyses < 

 rocks, minerals, and mineral waters for ttj 

 various divisions of general geology, but it ' 

 also conducting independently several invest 

 gations in mineralogy and physics. The phys 

 cal experiments are arranged with reference 1 

 certain questions in dynamic geology whos 

 settlement is demanded by the great proble: 

 of the condition of the earth's interior. 



A large portion of the work in general ar 

 economic geology can neither attain the be 

 results nor clearly set them forth in pub 

 cation without the aid of good topograph 

 maps ; and as only a small portion of the Uni 

 ed States has heretofore been accurately d 

 lineated, the Geological Survey has been fore* 

 to undertake the preparation of maps. S 

 great is the advantage to the geologist of b 

 ginning his field-work with a good map in li 

 hands, that it has been thought best to strengtl 

 en the geographic work as much as possible 

 the first years of the survey; and the ge 

 graphic corps is at present the largest sing 

 division of the organization. It is in tt 

 charge of Mr. Henry Gannett, and embraces 

 large number of subdivisions, to each of whk 

 is assigned the survey of an area. In makir 

 these surveys, the relative positions of distric 

 widely separated are determined by astronom 

 observation ; the relations of a limited numb< 

 of points within each district are establish^ 

 by triangulation ; and topographic details, sm 

 as the positions of ridges, hills, streams, town 

 and roads, are determined partly by the r 

 of the plane-table and partly by traverse su 

 veys. The delineation of reliefs is by meai 

 of contours representing lines of equal elev 

 tion ; and the altitudes necessary for the drp 

 ing of these contours are based on levelin 

 local differences of altitude being determine 

 partly by barometric methods and partly by tl 

 measurement of vertical angles. Great use 

 made of leveling data obtained from railwj 



