276 Common Science 



The dry leaves of the trees rustle and crumble. All 

 the animals and wood creatures gather around the muddy 

 pools that once were lakes -or rivers. People begin 

 saving water and buying it and selling it as the most 

 precious of articles. 



As the months go by, winter freezes the few pools 

 that remain. No snow falls. Living creatures die by 

 the tens of thousands. But the winter is less cold than 

 usual, because there is now so much water vapor in the 

 air that it acts like a great blanket holding in the earth's 

 heat. 



With spring no showers come. The dead trees send 

 forth no buds. No birds herald the coming of warm 

 weather. The continents of the world have become 

 vast, uninhabitable deserts. People have all moved 

 to the shores of the ocean, where their chemists are 

 extracting salt from the water in order to give them 

 something to drink. By using this saltless water they 

 can irrigate the land near the oceans and grow some food 

 to live on. Each continent is encircled by a strip of 

 irrigated land and densely populated cities close to the 

 water's edge. 



It is many years before the oceans disappear. But 

 in time they too are transformed into water vapor, 

 and no more life as we know it is possible in the world. 

 The earth has become a great rocky and sandy ball, 

 whirling through space, lifeless and utterly dry. 



That which prevents this from really happening is 

 very simple : In the world as it is, water vapor condenses 

 and changes to drops of water whenever it gets cool 

 enough. 



