TRANSACTIONS OF THE SECTIONS. 189 



enable them thoroughly to apprehend what are the present requirements of 

 science, and the classes of fact on which fresh observation must be brought to 

 bear to secure its advance. Nor does this involve any impracticable course of 

 study. Such knowledge as will fit a traveller for usefully participating in the 

 progi'ess of science is now placed within the reach of every one. The lustre 

 of that energy and self-devotion which characterize the better class of explorers 

 wiU not be dimmed by joining to it an amount of scientific training which will 

 enable them to bring away from distant regions enlarged conceptions of other 

 matters besides mere distance and direction. How great is the value to science 

 of the observations of travellers endowed with a share of scientific instruction is 

 testified by the labours of many living natm-alists. In our days this is especially 

 true ; and I appeal to all who desire to promote the progress of geographical science 

 as explorers, to prepare themselves for doing so efficiently, while they yet possess 

 the vigour and physical powers that so mucli conduce to success in such pursvuts. 



On the Physical Geography of iSontJi Africa, and Products and Prospects of 

 the Cape of Good Hope. By J. C. Beown, LL.D. 



The contour of South Africa has been likened to an inverted dinner-plate, on 

 the rim of which the colonies are situated. It has apparently been upheaved in 

 a mass. Much of it is covered by bushes of no great height ; but differences of 

 soil are indicated by other productions. Lignite and coal, copper and gold, rubies 

 and diamonds are found in difterent localities. Forests appear to have been much 

 more extensive than now. Corn and wine are produced. At present the inhabi- 

 tants are to a great extent pastoral ; but this is apparently a temporary and transi- 

 tional preparation for agriculture, for which are required moisture, labour, capital, 

 skill, and facilities for the transport of agricultural products at moderate expense. 

 Labour is being drawn to South Africa by diamonds and gold. Capital is being in- 

 creased by the investment of money obtained for these ; railways are rapidly extended; 

 and much water, which might be secured and utilized; at present escapes to the sea. 



On tlie late Inundations in France vieived in connexion with Rehoisement 

 and Gazonnement on the Alps, Cevennes, and Pyrenees, employed as 

 a means of ccctinyuishing and preventing the Formation of Torrents. By 

 J. C. Bkown, LL.D. 



In 1793 Fabre showed that torrents were attributable to the destruction of forests 

 on the mountains. In 1841 Sarell showed that torrents appear and disappear as 

 forests were destroj-ed and reproduced. In 1872 Cezanne showed that this relation 

 between forests and floods can be traced from preadamitic times to the present. 



In accordance with these views, in 1860 arrangements were made by the Govern- 

 ment for an expenditure of ten million of francs in planting with trees and bushes 

 and herbage mountain gTOund drained by torrents ; and vrithin ten years torrents 

 which were most destructive had become placid perennial streams. The Alpine 

 torrents are occasioned in autumn by storms of rain, and in spring by the melting 

 of snow. The late inundations were occasioned by a storm of rain causing a melting 

 of snow, and the substance of both flowing away simultaneously. Had the basins 

 drained been covered with forests the flood would have been delayed and warnino- 

 might have been given, and the flood would have been protracted, and it might 

 have occnn-ed without rising above the level of the river-banks. 



The rehoisement of all the bassin de reception of mountain-torrents has been 

 begun. Previous to the war a million of francs a year were being spent upon the 

 work. A selection of localities had to be made ; the propriety of the selection made 

 has never been questioned, and the magnitude of the disaster whicli has occurred 

 may be considered to justify the expediting of the work at even a greater expendi- 

 ture than was incurred during the first decade of the operations. 



