46 



SCIENCE. 



[N. S. Vol. V. No. 10b. 



two years. In 1869 James Stevenson was 

 appointed executive ofi&cer, a position which 

 he continued to fill with credit until the 

 end. In this year Persifor Frazer, jr., was 

 attached to the party as mining geologist, 

 and the line of geological travel, for such 

 was the character of their work during the 

 early years, led along the foothills of the 

 Eocky Mountains from Cheyenne to Santa 

 Fe. In 1870 it ran westward from Chey- 

 enne through the South Pass to Fort 

 Bridger, and back along the north slope of 

 the Uinta Mountains. 



In 1871, for the first time, two topo- 

 graphical assistants were attached to the 

 party, and Dr. A. C. Peale made his first 

 field season as mineralogist. The line of 

 travel this year led from Ogden, Utah, via. 

 Fort Hall, Idaho, to Fort Ellis (Bozeman), 

 Montana. From there an excursion was 

 made into the geyser region of the Upper 

 Yellowstone, and the enthusiasm aroused 

 by the view of these wonders of nature, and 

 the representations of Dr. Hayden on his 

 return, induced Congress to set the region 

 apart as a National Park. 



In 1872 the force was greatly aug- 

 mented, the names of Holmes as artist 

 and Gannett as astronomer first appeared 

 upon the rolls of the Survey, and F. H. 

 Bradley did a season's work as geologist 

 and paleontologist. Work was conducted 

 in two parties in the same general region 

 that was visited in the previous year. 



In the spring of 1873 James T. Gard- 

 ner, who had been chief topographer 

 of the 40th Parallel Exploration, was en- 

 gaged as chief geographer, and the areal 

 survey of Colorado was commenced. "Work 

 was carried on in three or more parties, 

 each in charge of a geologist or of a topo- 

 grapher, as the case might be; but, as on the 

 40th Parallel Survey, geologist and topo- 

 grapher worked side by side, and the one 

 had to suit his work to the exigencies of 

 that of the other. This system had cer- 



tain disadvantages, and on the 40th par- 

 allel it was sometimes found necessary to 

 go back to study key points. Such a trip 

 was made by Mr. King and the speaker to 

 the Wasatch Mountains in 1873. 



A. D. Wilson, who had also been topog- 

 rapher on the King Survey, joined the 

 Hayden Survey in 1874. The areal survey 

 of Colorado under the Hayden Survey was 

 continued for four years, and finally com- 

 pleted in 1876. 



Among the geologists, Marvine, who early 

 showed great ability, had charge of the 

 northern division for two seasons, but died 

 before he had written up his second season's 

 work. Dr. F. M. Endlich, who had studied 

 in Germany, where he served on the Geo- 

 logical Survey of Baden, joined the Hay- 

 den Survey in 1874, and continued to the 

 end in 1878. In Colorado he worked mostly 

 in the southern part of the area mapped, 

 as he was supposed to have a better knowl- 

 edge of igneous rocks than the others, but 

 in later years the practical test of his work 

 by other geologists in the field has proved 

 it to be less reliable than that of any of 

 the other geologists. 



Dr. A. C. Peale worked mostly in the 

 central part of the State, and as he gained 

 in experience proved himself a careful and 

 intelligent worker. The genius of the party 

 was W. H. Holmes, who, starting as an ar- 

 tist without previous geological training, 

 gradually developed, as a result of his study 

 of nature, a remarkable aptitude for struc- 

 tural geology. His drawings of mountains 

 have never been equalled by any other artist 

 in their combination of fidelitj'' to nature, 

 with artistic effect and keen insight into 

 geological structure. The paleontologists, 

 C. A. White, F. B. Meek, E. D. Cope and Leo 

 Lesquereux, contributed in their special 

 lines to the work in Colorado, the first also 

 doing considerable field work. Other spec- 

 ialists were attached to the parties at dif- 

 ferent times, and the sons of many promi- 



