286 National Geographic Magazine. 



by the slope of the land and the character of the soil. For 

 instance, on lands where oranges are cultivated, in the southern 

 part of the State, where rills are most generally used, water 

 cannot be applied by the flooding system, for the reason that 

 irrigation would be followed by ci-acking of the soil, so that 

 the trees would be killed. It is necessary on such land to 

 cultivate immediately after irrigation, and the method of applica- 

 tion is governed more by the soil than by the character of the 

 crop. 



We find in California very marked and important effects fol- 

 lowing irrigation. For instance, taking the great plains of Fresno, 

 in the San Joaquin valley : when irrigation commenced there 

 twenty years ago, it was 70 to 80 feet down to soil water — abso- 

 lutely diy soil for nearly 80 feet — and it was the rule throughout 

 the 'great plain, 20 miles in width and 25 miles in length, that 

 soil water was beyond the reach of the suction pump ; now, in 

 places, water stands on the surface, rushes grow, mosquitos breed,, 

 malarial fevers abound, and the people are crying for drainage; 

 and lands, whose owners paid from five to twenty dollars per acre 

 for the right to receive water, now need drainage, and irrigation 

 is considered unnecessary. The amount of water taken from 

 King's river which was, a few years ago, regarded as not more 

 than sufiicient for one tenth of the land immediately commanded 

 and that seemed to require it, is now applied to a fourth of the 

 whole area ; so that if irrigation keeps on, the time will come 

 when the whole country will require draining. 



In a district, where water is applied by the broad method, I 

 saw in 1877 enough water, by actual measurement of flow, put on 

 20 acres of land to cover it 18 feet deep, in one season, could 

 it all have been retained upon it. It simply soaked into the 

 ground, or flowed out under the great plain. Taking cross sec- 

 tions of this country, north and south and east and west, I found 

 that where the depth to soil water had, before irrigation, been 

 about 80 feet, it was then 20, 30, 40 or 60 and more feet down to 

 it. The soil water stood under the plain in the form of a moun- 

 tain, the slope running down 40 to 50 feet in a few miles on the 

 west and north. On the south and southwest the surface of this 

 water-mountain was much more steep. In the Kern river country, 

 we have a somewhat similar phenomenon. Irrigation, in the 

 upper portion of the Kern delta, afiiects the water in the wells 6 

 or 8 miles away. As I remember the effect is felt at the rate of 



