42 



cennexion with such labors. Many new and interesting species of 

 fossils, minerals, plants, and animals were collected. The geological 

 results are of the highest interest. In making the collections Dr. 

 Newberry was much assisted by Mr. H. B. Mollhausen, who also pre- 

 pared a valuable series of illustrations of the more remarkable locali- 

 ties along the route. 



Of the navigable portion of the river a careful and detailed survey 

 was made, the labor being principally performed by Mr. C. Bielawski, 

 of San Francisco. A set of meteorological and tidal observations and 

 a topographical reconnaissance from Fort Tejon to Fort Yuma were 

 faithfully conducted by Mr. P. H. Taylor, assisted by Mr. C. K. 

 Booker. 



The steamboat was taken to the mouth of the river, and there put 

 together by the engineer, Mr. A. J. Carroll, of Philadelphia. The 

 work w^as executed under peculiarly unfavorable circumstances, with 

 surprising expedition, and with an ingenuity and zeal that I cannot 

 too highly commend. During the trip up the river the post of pilot 

 was filled by Captain D. C. Robinson, who had for many years lived 

 upon the Colorado, and the successful ascent and descent of the river 

 may be attributed to the energy, coolness, and thorough capacity 

 with which he accomplished his duties. 



A small party accompanied the land explorations, consisting of 

 seven assistants and employes and a few Mexican packers, with an 

 escort of twenty men, under the command of Lieutenant John Tipton, 

 3d artillery. To this officer I am indebted for valuable assistance in 

 the astronomical and meteorological departments of the survey, and 

 for the excellent order and discipline maintained safely throughout 

 the trip among the individuals of his command. 



The train while following the bank of the river and crossing the 

 country was in charge of Mr. G. H. Peacock, of California, whose 

 good care and experienced management brought it safely through a 

 country of no ordinary difficulty. 



The work of computing the astronomical positions and barometric 

 altitudes is now in progress. Maps of the region explored are being 

 constructed by Mr. F. W. EgloSstein, who- accompanied the expe- 

 dition as topographer, and who neglected no opportunity of obtaining, 

 though often at the cost of great privation and exposure, an accurate 

 knowledge of every portion of the region traversed. 



During the explorations the health of all of the members of the 

 party was good, and no accident of any kind occurred. 



Respo<•tfull3^ your obedient servant, 



J. C. IVES, 

 l.sf Livutenant Topograplmvl Engineers^ 

 Cohnnandmj Colorado Exphving Expedition. 



A. A. Humphreys, 



Captain Topor/rap/iical Engineers, in charge of BureaiX 



of Explored ions and Sin-i^ei/s. War Department, 



