40 Modem forest economy. 



Section B. — Droughts. 



More generally felt, perhaps, than the scarcity of timber 

 and firewood, is the effect produced upon the humidity of 

 a country by the destruction of its forests. There is, I 

 believe, much of prejudice and much of error mixed up 

 with the prevailing popular beliefs on this subject; but 

 the confirmation of the underlying fact given by scientific 

 observations may warrant us in receiving, if necessary with 

 some allowance, the testimony which so many are ready 

 to bear — accepting the fact, though explaining differently 

 in what way the fact has been produced. Again and 

 again one hears that Spain has been ruined through 

 drought consequent on the destruction of her forests ; and, 

 as if by some general concensus, there have poured in 

 upon us, from lands remote from one another and diversely 

 conditioned, tales of privation, if not of distress, occasioned 

 by aridity consequent on the destruction of forests, remind- 

 ing one of the narrative given of the troubles and losses of 

 Job — while one is yet speaking in comes another; and* 

 while he is yet speaking, another; and while he is yet 

 speaking, another. 



It is a prevalent opinion that trees attract clouds and 

 rain ; and that mountains and the sea do the same The 

 phenomena which have given rise to these opinions can be 

 otherwise explained, and that more satisfactorily, by sup- 

 posing the clouds to have been formed where they appear, 

 and not been merely attracted thither ; and that that does 

 take place can be proved. 



In a volume entitled Hydrology of South Africa; or, 

 details af the former condition of the Cape of Good Hope, 

 and of the causes of its present aridity, with suggestions of 

 appropriate remedies for this aridity, I have shown that 

 the desiccation of that country is attributable, primarily, to 

 the drainage of much of the rainfall from the land to the 

 sea ; secondarily, to the evaporation of much which is not 

 so carried away, which evaporation, at one time greatly 



