2 Jo Illinois state dairymen*s association. 



the physics and characteristics of the western atmosphere gen- 

 erally. 



" This subject was presented in such a terse and concise 

 manner by Capt. Silas Bent, of St. Louis, in a paper read by 

 him before the Cattle Growers' convention, held at St. Louis in 

 1884, that I cannot do better than to quote it. He said in sub- 

 stance : 



" The western winds, dry and cold from the steppes of Asia, 

 in their passage to North America over the Kuro Simo, or 

 equatorial current of Pacific, take up an immense amount of 

 heat and moisture, reaching our shores saturated with vapor. 

 They find an inlet to the land when the Cascade range breaks 

 down. Flowing eastward they let down their moisture on the 

 dome of the continent and furnish the water supply for our whole 

 system of majestic lakes and rivers. But a different fate befalls 

 those winds that enter the country south of Oregon. Here they 

 are thrown against the western flanks of the Sierra Nevada, 

 where they are robbed of their moisture and thus descend, cold 

 and dry, on the plateaus of Utah and Arizona. In this condition 

 they move eastward, with just sufficient moisture to answer the 

 needs of vegetation on the slopes, and to whiten the crest of the 

 Rocky Mountains. After this total depletion they reach the 

 plains of Colorado and New Mexico. In this condition of dry- 

 ness, but with their heat being constantly augmented by radia- 

 tion from the parched plains, they keep on their movement east- 

 ward. 



" Now, if you will notice, this barometric trough of low pressure, 

 covering the states of western Indiana, Illinois south Wisconsin, 

 eastern Iowa, Missouri, and eastern Kansas is not much more 

 than at 



GOOD DRAINAGE HEIGHT 



above sea level, and is very low when compared with the plains 

 westward, that tower 4,ooo and 5,000 feet above it. When this 

 fact is fully appreciated, in conjunction with a knowledge of the 

 physical law that, like water, the air never moves until a way 

 is opened for it and a demand made on it by gravity, we can 



