352 SCIENTIFIC RECORD FOR 1882. 



NORTH AMERICA. 



The geographical work of the United States Coast Survey has con- 

 sisted, as heretofore, of topographic surveys for thfe exact definition and 

 delineation of the shore line, hydrographic surveys and resurveys where 

 changes have taken place, of the coast, harbors, and rivers, and in the 

 interior the continuation of the observations for the connection by tri- 

 angulation of the Atlantic and Pacific coasts, as well as astronomical de- 

 termination of important inland points and the carrying of a double line 

 of geodesic levels from the Atlantic coast at Sandy Hook to^the Missis- 

 sippi Eiver at Saint Louis. This line of levels is marked by permanent 

 bench-marks from 2 to 40 miles apart, and when completed to San Fran- 

 cisco will be of great value in furnishing reference points for measure- 

 ments of elevation. As the details of all this important work will be 

 found in the United States Coast Survey Reports for 1881 and 1882, it 

 is not worth while to enumerate them here. 



The United States Geological Survey was organized in the spring of 

 1879, taking the place of several independent geological and geograi)hical 

 surveys which had previously been conducted under the direction of 

 the Interior and War Departments. During the first two or three years 

 of its existence comparatively little geographical work was done. The 

 labors of the survey being confined mainly to mines and mining, the 

 surveys were in grej't part limited to the making of detailed maps of 

 mining districts. There was, however, some topographical work done 

 in Southern Utah and iforthern Arizona, in the neighborhood of the 

 Grand Canon of the Colorado, in order to complete a map commenced 

 and nearly finished by the survey of the Eocky Mountain region. In 

 addition to this, a survey was made of the volcanic region of the San 

 Francisco peaks in Northern Arizona. Some geographical work was 

 also done in connection with Mr. G. K. Gilbert's investigation of the 

 history of the ancient lakes in the Great Basin, and the climatic changes 

 indicated by them, but this was not of a connected character. 



In the year 1881 it was decided to increase the topographical force 

 with a view of preparing maps for the use of the geological corps. 

 Work was commenced in the western part of New Mexico, in the neigh- 

 borhood of Fort Wingate, where a base line was measured and triaugu- 

 lation extended therefrom in the neighboring region. A small area of 

 country was mapped in this neighborhood and also in the neighborhood 

 of the Moqui towns in Northeastern Arizona. 



In 1882 the topographical force was largely increased and work was 

 commenced simultaneously in several different sections of the country. 

 Besides the detailed surveys of mining regions, a division consisting of 

 two topographical parties commenced work in Northern California with 

 the view of mapping eventually the great volcanic range of the Cascades 

 extending across Oregon and Washington Territory, preparatory to a 

 study of its geological phenomena. The triangulation for this division 



