THE WATER CYCLE 



81 



The same spot after the winter rains. Compare the trees in the background in 



both pictures and you will see the photographs are taken at the same place. How 



do you account for the difference? 



the hot sun caused it to evaporate into vapor and pass 

 again into the clouds. Its next trip might take it to a 

 forest, where it would fall into the ground, remain there 

 for a time, be absorbed by the roots of the tree, and pass 

 up through the stem to the leaves, where perhaps it could 

 be used by the green leaves of the tree in the manufacture 

 of food. Or perhaps it might be evaporated through the 

 holes in the leaf as the tree made food in the sunlight. 

 Again in the air it might be condensed as dew and 

 then get into the soil again. Eventually, however, our 

 drop of water would become a part of the vapor of the 

 air, would become condensed, and again come back to 

 the earth as rain, or snow, or hail. This continual round 

 of water is known as the water cycle. 

 H. & w. sci. i 7 



