250 FOREST PROTECTION 



material is transported. River channels and reservoirs are 

 filled with detritus and deposits of rock and soil are left on 

 lands near the stream. Where the soil deposited is of fine 

 texture and fertile the lands covered may be benefited. The 

 harmful effects of erosion far outweigh any such advantage. 



A bare soil prevents the forest from performing its function 

 as a regulator of stream flow. Lacking the sponge-like cover 

 of Utter and humus a bare soil causes rapid surface run-off of 

 water instead of absorbing it and feeding it out slowly from 

 springs. Floods with their attendant damage are thus 

 caused and low and high water stages made more pronounced. 



This fluctuation in water level together with the eroded 

 material in the channel interferes with navigation, and often 

 necessitates expensive dredging operations. Power plants 

 and factories relying on water power require a continuous and 

 uniform supply of water rather than one which fluctuates 

 widely in volume. 



Smoke from forest fires has interfered with industry and 

 caused extra expense by producing dark days and dry fogs.^ 



Injury to Other Property. — Buildings, five stock, and prop- 

 erty of all kinds are at times threatened by forest fires and 

 serious losses result. The principal loss is to property found 

 within the forest or in small clearings surrounded by woods. 

 Whole towns have been wiped out by forest fires. 



Injury to Human Life. — Rarely if ever in the United States 

 does a year pass without loss of human fife as a direct conse- 

 quence of forest fires. The greatest loss of life on record in 

 any one fire took place in the Peshtigo fire of October, 187 1, 

 in Wisconsin. Fifteen hundred persons perished in this fire.^ 



Character of Forest Fires. — Forest fires are divided into 

 three classes: ground, surface and crown fires. 



Ground fires occur only where thick accumulations of 

 humus or duff are found and burn in this layer of organic 



