94 IS IT GOING TO EAIN? 



aiosphere as the storm-centre travels along, was 

 new wool not forthcoming from the white sheep and 

 the black sheep that the winds herd at every point, 

 all rains would be brief and local ; the storm would 

 quickly exhaust itself, as we sometimes see a thunder- 

 cloud do in summer. A storm will originate in the 

 far West or Southwest those hatching-places of 

 all our storms and travel across the continent, and 

 across the Atlantic to Europe, pouring down incal- 

 culable quantities of rain as it progresses and recruit- 

 ing as it wastes. It is a moving vortex into which 

 the outlying moisture of the atmosphere is being 

 constantly drawn and precipitated. It is not properly 

 the storm that travels, but the low pressure, the storm 

 impulse, the meteorological magnet that makes the 

 storm wherever its presence may be. The clouds 

 are not watering-carts, that are driven all the way 

 from Arizona or Colorado to Europe, but growths, 

 developments that spring up as the Storm-deity 

 moves his wand across the land. In advance of the 

 storm, you may often see the clouds grow ; the con- 

 densation of the moisture into vapor is a visible proc- 

 ess, slender, spiculae-like clouds expand, deepen, and 

 lengthen; in the rear of the low pressure, the re- 

 verse process, or the wasting of the clouds, may be 

 witnessed. In summer, the recruiting of a thunder- 

 storm is often very marked. I have seen the clouds 

 file as straight across the sky toward a growing storm 

 pr thunder-head in the horizon as soldiers hastening 

 to the point of attack or defense. They would grow 



