8 CONCLUSION OF OFFICIAL REVIEW, ETC. 



Under the appropriation made at the last session for the continuation of these surveys and 

 other purposes, three parties have been in the field during the past season. 



One of tliese was directed to make examinations connected with the routes of the 32d and 

 35th parallels. This survey has greatly improved the aspect of the former route by changing 

 the line for nearly half the distance between the Rio Grande and the Pimas villages on the 

 Gila river from barren ground to cultivable valleys, and entirely avoiding a Jornada of eighty 

 miles, which occurs in that section ; also by the discovery of an eminently practicable route 

 through cultivable country from the plains of Los Angeles, along the coast and through the 

 Salinas valley, to San Francisco. The connexion originally proposed between these points was 

 by way of the valley of San Joaquin and the Great Basin. 



The attention of this party was also directed to an examination into the practicability 

 of procuring water along certain parts of the route where it is now deficient. The report 

 shows that it may be obtained by common wells at distances of about twenty miles. 



From the result of this exploration, moreover, it appears practicable to obtain, at a small 

 expense, a good wagon road, supplied with water by common wells^ from the Rio Grande down 

 the San Pedro and Gila and across the Colorado desert. Such a road would be of great advan- 

 tage in military operations, would facilitate the transportation of the mail across that country, 

 and relieve emigrants pursuing that route from much of the difficulty and suffering which they 

 now encounter. 



A second party was charged with the duty of testing the practicability of procuring water by 

 artesian wells, on the Llano Estacado, an arid plain, which has been heretofore described as 

 a desert. The experiment has so far demonstrated its 2:)racticability as to leave little doubt 

 of its final success ; it will be continued, however, until the problem shall have been fully 

 solved. 



The examinations into the feasibility of causing subterranean streams to flow upon the surface 

 from artesian wells, though undertaken in connexion with the practicability of a railroad, if 

 they should prove entirely successful, will have a value beyond their connexion with that object 

 in the reclamation of a region which is now a waste, and its adaptation to the pastoral, and, 

 perhaps, the agricultural uses of man. 



The third party was directed to conduct an exploration from the Sacramento to the Columbia 

 river, with a view to ascertain the practicability of a route to connect the valleys of those rivers. 

 The oflicer in charge has reported the successful completion of the duty, but has not given 

 details. The same ofiicer has been directed to make a reconnaissance of the Sierra Nevada in 

 the vicinity of the head branches of Carson river. 



The prosecution of instrumental surveys, accompanied by an investigation into many branches 

 of physical science simultaneously over lines of such length, and embracing such an extent of 

 latitude, is a work of greater magnitude than any of the kind hitherto undertaken by any 

 nation ; and its results have not only proved commensurate with the amount of work done, but 

 possess a value peculiar to the scale on which it has been conducted, as affording a basis for the 

 determination of some questions of science which no number of smaller and detached explora- 

 tions could have furnished. Should means be granted pursuant to the estimate in the report 

 referred to, for continuing these explorations, I have every confidence that the expenditure will 

 be well repaid by these contributions to our knowledge of the interior of the country. 



The facts developed by these surveys, added to other information which we possess, suggest 

 some considerations of great interest with regard to our territory on the Pacific. They exhibit 



