11 



of riboisement and the regeneration of the mountains is one of the most in-' 

 teresting which man has to solve, but it requires time and money, and 

 with the authorities and political assemblies, technical knowledge which 

 is aa yet but very sparingly possessed. It is by books so substantial as 

 yours, sir, that public opinion can be prepared to face the importance 

 of this great work.' 



IX.— Hydrology of South Africa ; or Details of the 

 Former Hydrographic Condition of Cape of Good 

 Hope, and of Causes of its Present Aridity, with 

 Suggestions of Appropriate Remedies for this 

 Aridity. Price lOs. 



la this the desiccation of South Africa, from pre-Adamic 

 times to the present day, is traced by indications supplied 

 by geological formations, by the physical geography or the 

 general contour of the country, and by arborescent pro-! 

 auctions in the interior, with results confirmatory of the 

 opinion that the appropriate remedies are irrigation, 

 arboriculture, and an improved forest economy : or the 

 erection of dams to prevent the escape of a portion of 

 the rainfall to the sea — the abandonment or restriction of 

 the burning of the herbage and bush in connection with 

 pastoral and agricultural operations — the conservation and 

 extension of existing forests— -and the adoption of measures 

 similar to the riboisement and gazonnement carried out in 

 France, with a view to prevent the formation of torrents, 

 and the destruction of property occasioned by them. 



M. Jules Clave", of world-wide reputation as a student 



of Forest Science, wrote in the Bevue des Deux Mondes of 



1st May 1882 :— 



[Translated.'] ' Since the first travels of Livingstone, the African 

 continent, hitherto inacessible, has been attacked on all points at once. 

 By the north, and by the south, by the east, and by the west, hardy 

 explorers have penetrated it, traversed it, and have dragged from it 

 some of its secrets. Travellers have paid tribute and done their work 

 in opening up a path ; it is now for science and civilisation to do theirs, 

 in studying the problems which present themselves for investigation ;/■ 

 and in drawing in the current of general circulations the peoples and 

 lands, which appear as if destined to stand outside ; and in causing to' 



