12 



contribute to the increase of social wealth the elements of production 

 previously unknown. Thus are we led to receive with interest works 

 which can throw a new light on the condition of regions which may 

 have been known for a long time, and which make known the conditions 

 of their prosperity. It is under this title that the work of the Rev. J. C. 

 Brown on the Hydrology of South Africa appears deserving of notice ; 

 but it is so also from other points of view. Mr Brown, after a previous 

 residence in the colony of the Cape, whither he had been sent in 1844 

 as a missionary and head of a religious congregation, returned thither 

 in 18lj3 as Professor of Botany in the College of South Africa, and he 

 remained there some years. In both of these positions he had occasion to 

 travel through the colony in all directions, and had opportunities to col- 

 lect most valuable information in regard to its physical geography. Mr 

 Brown on going out to the Cape knew nothing of the works which had 

 for their object to determine the influence of forests on the climate, on 

 the quantity of rain, and on the river-courses in Europe ; he had never 

 heard mention of the work of M. Surell on the torrents of the Alps, or 

 of that of M. Mathieu on forest meteorology, nor of those of M. 

 Domontzey, Costa de Bastelica, and so many others on the subject of 

 riboisement; and yet in studying by himself, and without bias, the 

 climatic condition of South Africa, he came to perceive that the dis- 

 turbances in the regularity of the flow of rivers within the historic 

 period should be attributed in a large measure to the destruction of 

 forests ; and he meets in agreement on this point the savants whose 

 names have been mentioned. We have thougbt it might not be with- 

 out interest to readers of the Revue to have in the lines of Mr Brown a 

 collection of phenomena which, in their manifestation at any speci- 

 fied point are not less due to general causes, the eflfects of which 

 may be to make themselves felt everywhere where there may be 

 existent the same conditions than to aught else.' And there follows a 

 lengthened article in illustration. 



X.— Water Supply of South Africa, and Facilities for 

 the Storage of it. Price 18s 6d. 



In this volume are detailed meteorological observations 

 on the humidity of the air and the rainfall, on clouds, and 

 ■winds, and thunder-storms ; sources from which is derived 

 the supply of moisture which is at present available for 

 agricultural operations in the Colony of the Cape of Good 

 Hope and regions beyond, embracing the atmosphere, the 

 rainfall, rivers, fountains, subterranean streams and reser- 

 voirs, and the sea ; and the supply of water and facilities 

 for the storage of it in each of the divisions of the colony 



