208 EFFECTS OF FOKEST TEGETATIOJT O'S CLOIATE. 



102-83 in 1847, and the minimum 65-99 in 1818. '•' Altliougli tlie 

 rainfall thus varies according to local circumstances, erery 

 particle of moisture is wrung out of the clouds in their passage 

 from the Indian seas by the intervention of the mountains;" and 

 so far as this is the case, "the forests," says Mr. Markham, "which 

 clothe their sides and fill the valleys and ravines on their plateaux, 

 have the effect of regulating the flow of water to the eastward, but 

 I cannot see that their presence or absence can have any influence 

 on the actual amoimt of rain which falls on the hills." Of course 

 this is sound reasoning, applicable to all very lofty mountains, 

 whether in India or Aus'h.'alia, and probably so long as the 

 primeval forests remained the supply in the rivers would con- 

 tinue at the usual average amount in a series of years. This 

 consideration meets the argument that though in ISTew South 

 Wales the smaller streams have been partially or nearly alto- 

 gether dried, as in the Illawarra, yet in the larger rivers, where at 

 present the forests at their sources or on their banks have not 

 yet been destroyed, the apparent body of water may be nearly 

 the same as of old, though this is altogether conjectural in the 

 absence of past or present measurements. 



But the argument itself " tvill not hold tcater'''' any more than 

 the river channels when destruction of the regulating forests is 

 taken into account. Let us attend to the eye-witness before us. 

 What, after his admissions, does Mr. Markham say ? — 



" The settlement of planters on the hills has given rise to 

 wide-spread destruction of the primeval forest. The planters 

 are occupied chiefly in the cultivation of coffee, to which has 

 been recently added tea, and the quinine -yielding cinchona of 

 South America. These tlu'ee products give rise to the felling 

 and clearing of forests in the formation of plantations — making 

 a total of 60,000 acres of forest destroyed. iSTor has the process 

 by any means reached its limit, and a great change is taking- 

 place in the physical condition of the hill districts. 



" One obvious consequence of the destruction of the forests is 

 an increased rapidity of surface drainage, giving rise to sudden 

 and destructive floods at the outlet on the plains, where the 

 change of slope causes a diminution of velocity, and to injurious 

 freshes in the irrigating rivers after they have reached the 

 plains." 



" The effect of vegetation is undoubtedly to retard elevation 

 and to check the rapidity of drainage ; and the removal of forests 

 of course has an opposite effect. The hill districts of India are 

 now affording proofs of this law of Nature. The floods caused 

 by the monsoon rains are yearly increasing in size and violence." 

 He gives several instances, and adds : " All this is clearly due to 

 the extensive clearance of forests, owing to which the rain-water 

 rushes off the surface instead of sinking into the earth and 



