REPORT OF THE SECRETARY. 49 



Aside from the topographical work of 1875, gratifying results in eth- 

 nological research were obtained by a party of the California section 

 under Dr. H. 0. Yarrow, detailed for that purpose. Extensive burial- 

 places were discovered, and it is estimated that the remains of no fewer 

 than 5,000 individuals were exhumed. The valuable collection made 

 has been submitted to Professor F. "W. Putnam, of the Peabody Museum 

 of Archaeology, for examination and study. Dr. Yarrow's report fully 

 describes the explorations of this party. 



The geology of portions of Southern California, Arizona, New Mexico, 

 and Colorado was examined and reported upon by Prof. Jules Marcou, 

 Dr. Loew, and Mr. A. E. Conkling. Professor Marcou makes valuable 

 additions to the knowledge of the field visited by him. Dr. Loew de- 

 scribes much of geological interest in his work of the year, besides mak- 

 ing a large collection of specimens. He also determines the chemical 

 composition of alkaline and other deposits, and of the waters of thermal 

 and mineral springs of Southern California, and analyzes the ores from 

 several mines. Mr. Conkling made a rapid and interesting examination 

 of the mountain geology from La Veta Pass to the head of the Pecos 

 River. Much valuable mining information of a descriptive character 

 was obtained by the different parties. 



The meteorological and hypsometrical methods, as described by Lieu- 

 tenant Marshall, show a commendable state of efficiency. The economic 

 botany and agriculture of Southern California received careful consider- 

 ation from Dr. J. T. Rothrock, acting assistant surgeon United States 

 Army, and his observations cannot fail to interest those in search of in- 

 formation regarding that country. In the field of zoology Mr. BI. W. 

 Henshaw displayed his usual energy. During the season 700 ornitho- 

 logical specimens were secured, representing 127 species. The report 

 of this gentleman describes the habits, peculiarities, and localities of 

 these birds. 



The operations of the season of 1876 were carried on in portions of 

 Colorado, New Mexico, California, and Nevada. The Colorado party, 

 traversing atlas-sheets 52, 53, 61, and 62, occupied 10 main and 51 

 secondary triangulation stations, with numerous three-point, sextant 

 latitude, and meander stations, covering an area of 4,800 square miles. 

 The party in New Mexico, operating upon an area of 7,500 square miles 

 in atlas-sheets 62, 69, 70, 77, 78, and 84, occupied 15 triangulation, 191 

 three-point, and a large number of subordinate stations. Correspond- 

 ing results were obtained by each of the four parties acting in Nevada 

 and California. Base-lines were measured at Sutro, Nevada, and Colo- 

 rado Springs, Colo. 



The working force of the season was disposed as follows: (1) the 



California section, in charge of Lieutenant Wheeler, with its several 



parties under the command of Lieutenants Tillman, Symons, Birnie, 



and Macomb ; (2) the parties of the Colorado section, under Lieutenants 



S 4 



