11 
of réboisement 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 as 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 10s. 
In 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- 
ductions 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 rébotsement 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 Clavé, of world-wide reputation as a student 
of Forest Science, wrote in the Revue des Deux Mondes of 
Ist May 1882 :— 
nslated.] ‘Since the first travels of Livingstone, the African 
ae ee 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 
