- OF T H .-v 



UNWERSIT 



CALIFOHJ 



CHAPTER I. 



THE ARID REGION. 



It has again taken forty years of wandering 1 in the 

 wilderness before entering into the fuller possession of 

 our promised land. 



ABID Arid agriculture is the agriculture of the 



AGRICULTURE arid region. An arid country is one in which 

 there is a small amount of rainfall. The word 

 rainfall as here used means the total precipita- 

 tion during the year, including rain, snow, sleet, 

 and hail. A "small amount of rainfall" means 

 an amount which used to be considered insuffi- 

 cient for the raising of field crops without the 

 artificial application of water. The line between 

 possible farming by natural rainfall and impos- 

 sible farming with natural moisture was for- 

 merly somewhat definitely fixed. More than 

 twenty-five inches of precipitation in a year was 

 considered sufficient for the production of gen- 

 eral crops. In places where between twenty-five 

 inches of rain and fifteen inches occurs farming 

 was considered uncertain, so regions receiving 

 this amount of moisture were classed as sub- 

 humid, or semi-arid. 



PROGRESS In parts of the country where the total rain- 



STEP BY f a u j s ] ess than fifteen inches there is compara- 



tively little natural vegetation. Early statesmen 

 named the whole region the "Great American 



