14 THE CLIMATIC FACTOR AS ILLUSTRATED IN ARID AMERICA. 



the diagram presents a wholly different appearance: the two curves show agreement 

 instead of opposition. The effect of such agreement upon the economic hfe of the country 

 is marked. During the late eighties, when both summer and winter rains were on the 

 increase, the cattle industry flourished as at no other period. In the early nineties, how- 

 ever, when the rain of both seasons decreased, dire distress prevailed. Cattle died by the 

 thousand and the industry received such a blow that on many ranches there are now 

 only hundreds of animals where then there were thousands. The peculiar fashion in 

 which the summer and winter curves show opposite phases part of the time, and then 

 suddenly agree, suggests various speculations as to the cause. It looks as if there might 

 be more than one type of cycUcal or periodic variation in the activity of the earth's at- 

 mosphere. One type perhaps causes agreement and one type disagreement. Here, as 

 in the case of the contrast between the precipitation of high and low regions, it is too early 

 to attempt to form positive theories. 



