196 EFFECTS OF FORESTS ON SPRINGS AND RIVERS. 



and finally, that througli these changes the lowest and the mea7i 

 water-levels in brooks, streams, and rivers are being continuously 

 lowered, and the quantities of water delivered by them continuously 

 diminished. 



" If this continuous diminution, which has been going on for the 

 last 140 years, is to go on continuously still, then will these results 

 and changes on the surface of the earth entail on coming generations 

 evils, and evils of incalculable extent and magnitude. Through the 

 lowering of the level, and reduction of the rivers and of the sub- 

 terranean drainage, and also through the alternation of very wet and 

 very dry years, — such as is shown, by the diagram referred to, to be 

 prevailing, — will the fertility and productiveness of the land be 

 reduced in no inconsiderable degree, and not a few lands now covered 

 with luxuriant vegetation will become veritable deserts, cheerless and 

 desolate. 



" After the drying up of many brooks and streams, and after the 

 conversion of streams and rivers into torrents, in consequence of these 

 changes men would have to go for their water supplies for drinking 

 and for domestic use, and for other purposes, either to the deeper- 

 lying water-bearing strata of the earth, or to a greater distance from 

 their dwelling ; whereby the cost of the water consumed would be 

 increased, while many industrial establishments and manufactories 

 would be deprived altogether of the supply of water indispensably 

 necessary to their operations, and would have either to adopt expen- 

 sive means of providing a substitute for what has been lost, or remove 

 to some remote district where brooks and rivers have not as yet been 

 deprived of their water supplies. 



" Finally, by the continuous diminution of water in streams and 

 rivers, the former would become quite dry through the greater part 

 of the year, and the latter would become unnavigable. 



" As, through the consideration of what has been advanced, it may 

 thus be seen that, through the continuous diminution and lowering 

 of the flowing water on the surface of the earth, there is imperilled — 

 and that to a great extent — not only the prosperity and the health, 

 but also the existence of future generations, it is desirable that 

 numerous students of physical science should be incited to further 

 research into the cause of these intimately connected phenomena, and 

 then to devise measures to avert the impending calamity, in so far as 

 it may be within the scope of man's power to do so." 



The author adds : — '' I have given myself also to an attempt to 

 a solution of this difficult problem, and I give the results of my 



