GEOLOGICAL SUEVEY OF THE TERRITORIES. 309 



DuriDg my examiuatiou of the central and southern sections in the 

 summer of 1872, 1 found that in some respects I was compelled to change 

 the opinion I had previously formed from hasty passages through the 

 State. For example, I am now satisfied that Platte Valley can produce 

 crops of the cereals without irrigation farther west than I had formerly 

 supposed. Not that the amount of rain which falls on this valley is 

 any greater than that which falls on the adjoiuiug plains, but the moist- 

 ure is longer retained ; and, more than this, I strongly" suspect that these 

 valley-bottoms are large! 3^ underlaid with sand-deposit through which an 

 underground river permeates. While I am of this opinion in regard to 

 this great valley, on the other hand I am now pretty thoroughly con- 

 vinced that the sufQcient supply of rain on the upper plains does not 

 extend as far west as I formerly supposed. For Southern Nebraska, I 

 do not think this can safely be placed any farther west than Fort 

 Kearney, except along the immediate valley of Eepublican Fork, and 

 north of Platte this line will probably bend considerably east. 



Notwithstanding it is doubtless true, as claimed by the residents, that 

 the subsoil is well adapted to sustain droughts by its capability of 

 absorbing moisture, yet it is also true that the evaporating jjower of the 

 air is greater than is usually supposed. The records of the signal- station 

 at Omaha show that on the 4th of April the difference between the wet 

 and dry bulb was as much as 27°, which, considering the fact that this 

 is on the bank of the Missouri Eiver, the date early in the spring of a 

 rather wet season, is very great and indicates a very dry atmosphere. 



There is another thing in connection with this subject, which I think 

 is true both of this State and Kansas ; that is, that the amount of rain 

 does not diminish so gradually as we go west as I had supposed, the 

 supply in the eastern i:»art of these States being almost equal to that of 

 the States immediately east of them. For instance, the average of five 

 years (1866-1870) in Nebraska was 31.47 inches, while that of Iowa was 

 40.65 inches; Kansas 40.98 inches, while that of Missouri was but 38.33 

 inches. But if we go westv\-ard to the middle of these States the pre- 

 cipitation will diminish to not more than half this amount. We should 

 therefore bear in mind that these records which appear so favorable 

 apply only to the eastern third of these States. Taking the average of 

 all the stations in Nebraska for the years named, w^e find them to be as 

 follows: 1866,27.07 inches; 1867,28.41 inches; 1868, 33.28 inches; 

 1869, 42.11 inches; 1870,26.47 inches. This subject will be more fully 

 discussed in my report on the climatology of the West. 



The. following answers to the inquiries contained in a circular sent 

 out by the Secretary of the Interior, at the request" of Dr. Hayden, is 

 so full, and, as a general thing, so fair a statement in regarcl to the 

 agricultural resources of southeastern Nebraska that I think it is proper 

 that it should be inserted here. It is true it is from the land-office of 

 the Burlington and Missouri Eiver Eailroad Company, who are deeply 

 interested in sustaining the character of the lands in this section, yet^ 

 after a visit in person to the section described, I think I may safely state 

 that it is correct. A few drawbacks are not mentioned, but I will allude 

 to these, as they were not directly embraced in the questions propounded: 



STATE OF NEBRASKA. 



To the Secretary of the Interior, Washington, D. C. : 



Sir : In accordance with the request coutained iu " Circular No. \," addressed from 

 the "Department of the Interior, Washington, D. C," and dated " March 20, 1872," I 

 have the honor to report on the description of laud, climate, productions, and markets 

 of a portion of the State of Nebraska. I answer the questions iu the circular relating 

 to this section of land, and tlie questious and answers I number consecutively. 



