210 



ELEMENTS OF GENERAL SCIENCE 



of success. There are in the United States (fig. 102) over 

 10,000,000 acres of artificially watered lands, and projects 

 under construction will add much to that figure. There are 



V) 



FIG. 102. Irrigation in the United States 



The map shows the location of the more important government irrigation projects. 



There are in addition many other areas irrigated by government, private, and 



state enterprise. From map by United States Reclamation Service 



several methods of irrigation, but that along the banks of the 

 Rio Grande River may serve as a type. In the lower stretches 

 of this river the annual rainfall is quite low, but a large 



