1 6 Forests and Trees 



which falls on a forest, ioi per cent evaporates, 20 per cent 

 is stopped by the foliage of the trees, 25 per cent is ab- 

 sorbed by the layer of decayed leaves forming the forest 

 floor, and 44 per cent soaks into the soil. Of the rain 

 falling on the open ground, 68i per cent evaporates and 

 31^ per cent is absorbed by the soil. The effect on the 

 whole country of this preservation of water is greater than 

 people imagine, and it can be estimated only by consider- 

 ing the results in places where the forest has been cleared 

 away from the sources of the streams. In the eastern 

 provinces there were many rivers that supplied water to 

 run mills and factories through the whole summer. These 

 rivers, too, were not subject to floods in the spring. As 

 the forests surrounding their sources were gradually cleared 

 away, two results were soon apparent. The rivers became 

 flood streams in the spring freshets, even flooding towns 

 on their banks and carrying away bridges and buildings. 

 Then, too, the water began to fail in the summer, and 

 factories, which had formerly been run by water power, 

 now have to depend on steam through a good part of the 

 year. This effect has been visible wherever a river basin 

 has been largely cleared. 



The late Mr. Cecil B. Smith, C. E., formerly chairman of 

 the Timiskaming Railway Commission, says that many 

 rivers in southwestern Ontario, including the Thames, 

 Grand, Credit and Humber, all at one time possessed 

 valuable water powers, but that when their basins were 

 cleared of forests these water powers were all ruined. 



Mr. W. H. Brethwait, C. E., says that the minimum flow 



