196 



THE CLIMATIC FACTOR AS ILLUSTRATED IN ARID AMERICA. 



Fig. 5G. — Storm Frequency. May. 



130 125 120 lis no 105 100 95 90 85 80 73 70 65 60 55 



US' no' 105' 100* 95* 90' 85' SC 75" 70' 



Fig. .57. — Storm Frequency. June. 



