R GEOGRAPHY. 197 



he proceeded from Loando to Ambassi, or San Salvador, the 

 upper town of Congo, which had not been visited by any sci- 

 entific traveler since the sixteenth century. The principal 

 object he had in view was to become acquainted with the peo- 

 ple and the country sufficiently to carry on an expedition 

 along the Congo River, which he had had in contemplation 

 for a long time. 17 (7, xi., 1872, 431. 



EXPLORATIONS BY PROFESSOR HAYDEN IN 1872. 



The very liberal appropriation made by Congress for the 

 United States Geological Survey of the Territories during the 

 Forty-second Session, for the year 1872, enabled the chief ge- 

 ologist to organize two large and well-equipped parties for 

 field work. These parties were each provided with a topog- 

 rapher, astronomer, meteorologist, and geologist, with their 

 assistants, and a number of naturalists. One party, under the 

 immediate direction of Professor Hay den, the chief geologist, 

 took Fort Ellis, Montana, as its initial point, proceeding up 

 the valley of the Yellowstone, over pretty much the same 

 ground as the party traveled the previous season. The sur- 

 vey of this region was completed, with much detail, to the 

 sources. Then the Madison and the Gallatin rivers, with their 

 various branches, were carefully surveyed from their sources 

 to the Three Forks. A map of the region explored will be 

 prepared in contour lines of 100 feet. The second party, un- 

 der the direction of Mr. James Stevenson, surveyed a route 

 from Ogden, Utah, to Fort Hall, Idaho, where full prepara- 

 tions were made for a pack train, with supplies, to proceed up 

 Snake River. The party passed up the west side of Snake 

 River, and, forcing their way across the mountains, made a 

 careful survey of the little-known Teton Range, then passed 

 up the valley of Henry's Fork, entered the Madison through 

 the Targee Pass, and reached the Geyser Basin of the Madi- 

 son on the 14th of August. Both parties met in this basin on 

 the same day, though starting from points several hundred 

 miles distant from each other. 



The first party descended the Madison River, while the sec- 

 ond party explored the Snake River from its sources to Fort 

 Hall. The results of these explorations were most satisfac- 

 tory, and will prove of great importance to science, as well as 

 of vast practical value to the country. 



