DRY FARMING CONGRESS. 



201 



tion to the evaporation then the man at Amarillo, in order not to have 

 to work harder to conserve the moisture than the man in North Dakota, 

 would need practically twice the rainfall. 



Thus up on the high plains, the Staked Plains of Texas, you will no- 

 tice as you get down here in this well-recognized desert region the evapora- 

 tion is very much higher. Here at El Paso it is 58 inches; in Arizona it 

 is 53. At Yuma, Arizona, it is 56. Here is a high measurement in New 

 Mexico, on the boundary between California and Lower California, 72 

 inches. This is a single measurement, made by Prof. Fortier, who ad- 

 dressed you the other morning. Here are tfie conditions in Utah. Here 

 are the evaporation' measurements made at your station at Logan, 34 

 inches. This figure represents the evaporation at the fort (Fort Douglas) 

 out here, taken some years ago, 31 inches. This, of course, all refers 

 to the six summer months. Now you will notice that the conditions here 

 are very little higher than those in North Dakota — very little higher than 

 those in North Dakota, and that they are nowhere near as severe in the 

 arid regions as in Texas, or Kansas, or in Nebraska. 



The settler then must realize that the annual rainfall is not the only 

 factor to consider when he selects his homestead in some Trans-Missouri 

 jtate. The greater the evaporation in any given locality, the harder must 

 he work to conserve moisture sufficient to produce his crops. The char- 

 acter of the rainfall, the prevalence of hail, frost, hot winds, high winds, 

 the physical properties of the soil of the locality, its depth, porosity, ten- 

 dency to make and clod, and the amount of organic matter and plant 

 food it contains are all factors which the prospective settler should con- 

 sidei. 



We will now have the next slide, which will show some of the work 

 which we have been doing during the past year in connection with co- 

 operative stations of which I have been speaking. This represents the 

 evaporation in detail at the eight stations, which are scattered through 

 the Great Plains, to which I called your attention, during the past summer, 

 and you will note, of course, that the highest evaporation is that at Ama- 

 rillo, Texas — 54 inches — for the six months. This measurement began the 

 first of April. The vertical lines represent the different months, and the 

 horizontal lines give the total evaporation for that point. In other words, 

 during the month of April the evaporation at North Platte is something 

 over eight inches, while at Hymore, for the same period, the evaporation 

 was only four inches. You will notice that these lines are practically 

 straight. That point would come out more clearly if the curtain were 

 flat, but they are not entirely straight, as you will notice by the next slide. 

 The lower curves here you see you have the evaporation for four stations 

 instead of eight, as I said, represented here — Amarillo, in Texas, Hayes, 

 Kansas; North Platte, Nebraska; Hymore, South Dakota. We have be- 

 low the corresponding curves for precipitation during this same period 

 of six months — during Ixactly the same time. While, as you will see, the 

 evaporation at Amarillo is, the highest the precipitation at Amarillo dur- 

 ing this year was the lowest, and we will see the results of that condi- 



