REVIEWS 597 



The following quotation from Mr. H. Vander Veen, C. E., for many 

 years consulting engineer in Peking, indicates the necessity for the 

 elimination of the present load of silt in the streams if damage from 

 floods is to be reduced : 



"As long as the slope of the water level is such that a current can 

 be maintained strong enough to carry all the matter held in suspension 

 along, no harm is done. But the natural slope of the plain is, for sev- 

 eral rivers, insufHcient. In such a case the river is therefore forced 

 to get rid of the soil held in suspension along its way ; consequently 

 its bed gets raised, and in the long run the river has to find another 

 course, which it does by bursting its dikes to find in the lower lying 

 land the place where it can deposit its burden, which it could carry 

 no longer and for which no more room could be found in the old bed. 

 This is the case more or less with every river running through the plain 

 of China. 



"The only way to diminish this evil is to diminish the amount of soil 

 brought down from the mountains. And the reason for this enormous 

 quantity of silt coming down from the mountains is that those moun- 

 tains are bare, so that during a heavy rain nothing prevents the water 

 from rushing downward practically immediately after it has fallen, tak- 

 ing with it large quantities of soil, so that it reaches the river down 

 below more like torrents of mud than of water. Now, if those moun- 

 tains were planted with trees, not only would the water then be unable 

 to take away so much soil, but it would also reach the river graudally, 

 in a regular flow, divided over a longer period, and not within a few 

 hours, in fierce torrents. 



"It is impossible to lay too much stress upon the enormous importance 

 of afforestation. The deterioration of the various rivers in China would 

 never have reached its present stage if deforestation had not taken 

 place." 



The author discusses the efifects of forests on floods under the fol- 

 lowing heads : 



Forests and streamflow. 

 Forests and soil erosion. 

 Forests and floods. 

 He concludes that the problem of flood control in China is funda- 

 mentally a forest problem, because afTorestation is the only way by 

 which the present load of silt can be permanently kept from the water- 

 courses. J. W. T. 



Silviculture for Country Roadsides. P.y R. T. Fisher. Forestry 

 Association. Bulletin 123. 1918. 



Americans are everywhere, outside of our cities, extravagant in the 



use of land. Idle land. e\ en in the earlier settled parts of the country. 



