CHAPTER XXIII 



FORESTRY 



EVERY year property worth millions is destroyed and 

 hundreds of lives lost by floods. This comes largely 

 from cutting down our forests. The forests prevent 

 floods in a very simple way. The ground in the forest 

 is covered with leaves, and when rain falls they soak it 

 up like a sponge. Underneath the leaves there is soft 

 leaf mold, which also acts like a sponge. Underneath 

 this again are the spongy roots of the trees, which also 

 help to hold water. So the forest acts like a giant 

 sponge to catch the rain as it falls and hold it fast. 



All summer long it is moist and cool in the forest, and 

 when you dig down into the soil you find that it is full 

 of moisture. The water trickles slowly into the little 

 brooks and streams, so that they flow all summer long 

 and do not dry up. But if there is no forest to hold 

 it back, the rain runs off the bare soil, floods the lowlands, 

 and escapes to the ocean. Then the streams soon 

 cease to flow, the land dries up, and crops fail. 



Figure 175 shows what has happened in China where 

 the forest has been cut away and the land left bare and 

 exposed to the action of the rains. All of these hills 



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