106 feature's /flMracles, 



effects of these hot winds in open boats out on 

 the water before they could reach land. 



Hot winds prevail on the plains of Kansas 

 during the months of July and August that 

 are phenomenal in their intensity, so much so 

 that if they were widespread and of long con- 

 tinuance, like the northern blizzard, they 

 would be attended with great loss of life and 

 destruction to vegetation. Fortunately, they 

 come in narrow streaks and in most cases do 

 not blow more than from ten to thirty minutes 

 at a time. These hot belts are sometimes not 

 over 100 feet wide, and again they are as much 

 as 500. They are so hot and dry that green 

 leaves and grass are rendered as dry as powder 

 in a few minutes. These winds are probably 

 caused by the fact that at this season of the 

 year, when the prevailing wind is south- 

 westerly, the air becomes heated to a great 

 height, and are the resulting effect of certain 

 combinations of air currents in the higher 

 regions of the atmosphere that force the al- 

 ready heated air toward the earth. As the air 

 descends it is more and more compressed, 

 which causes it to become more and more 

 heated. We have already described the heat- 

 ing effect of compression upon air as shown by 

 the experiment with the fire syringe. It was 

 shown that air at normal temperature could be 

 suddenly compressed into so small a space that 

 the condensed heat, which was before diffused 



