82;^ B ihliog raplucal Notices. 



tains, have given us an insight into the structure and capabilities of 

 one of the most wonderful parts of the mighty North-American 

 continent. Here, before many years shall have passed, a great 

 population (with their railroads leading fi-om ocean to ocean, their 

 wealth of gold and silver, their wealth of iron and fossil fuel, of 

 fertile lands, forests, and pasturage, with their glorious mountains, 

 rivers, lakes, and geysers) will be utilizing what the Indian passes 

 almost unnoticed, and what the Surveyors, amidst obstacles and 

 dangers, with skill and enthusiasm, have mapped and descrilxxl with 

 scientific accuracy. Nor are the Antiquities by any means neglected. 

 See, for instance, Bulletin, 2nd ser. No. 1, for an account of the old 

 towers and cliff-houses of S.W. Colorado, and Prof. Leidy's illus- 

 trated paper on the Remains of Primitive Art in the Bridger Basin 

 of Southern Wyoming, and Dr. Thomas on the Ancient Mounds of 

 Dakota, in the Report for 1872. 



The Report of Progress in 1873 fully supports the character of 

 the work done in former years, and digested in former volumes, 

 giving excellent results for geographer, naturalist, aud geologist, and 

 supplying definite information as to the agricultural capabilities and 

 the mineral resources of the districts examined. Owing to the 

 distance of the Territory, and the hostility of the Indians in the 

 unsurveyed lands adjacent to Montana, Idaho, Wyoming, and Utah, 

 already reported on, the Survey operations were carried on in 1873 

 in the Middle-Park, South-Park, and San-Luis districts of Colorado 

 and New Mexico, especially as this region is becoming rapidly de- 

 veloped by railroads and increased population. The ground had to 

 be geographically surveyed by triangulation, which the more com- 

 plete staff of 1873 efficiently carried out. The methods of topo- 

 graphical work are described in the Report (p. 6 &c. and p. 627 &c.) ; 

 and the necessity of combining topographical observation with geo- 

 logical research is insisted on. Contoured maps are especially recom- 

 mended as of use to the geologist. " He may note by his observa- 

 tions, and express by means of vertical sections, the arrangement of 

 strata throughout a certain mountain, ridge, or range ; and the con- 

 tour given on the map will then greatly facilitate his work, by en- 

 abling him to define more correctly than in any other way the limits 

 of the successive strata " (p. 7 & p. 12). Part IV. of the Report 

 (pp. G27-684), treating of the geography and topography, supplies 

 the elevations of many datum-points on the railways, great lakes, 

 and rivers of the United States, and on the Rocky Mountains, with 

 good maps, by Messrs. Gardner, Gannett, and Ladd ; indeed, besides 

 the heights, other points are treated of throughout by the geographers, 

 such as means of communication, distribution of timber, grass-lands, 

 and population. 



The geologists of the Expedition, under Dr. Hayden, were Mr. 

 Marvine, Dr. Peale, and Dr. Endlich, and Iheir assistants. With 

 the willing cooperation of the geographers, and of Messrs. Jackson 

 and Holmes (talented artists and topographers), the Surveyors have 

 worked out an extensive area of the great Nebraska foi-mations and 



