44 LIMITS OF HUMAN POWER. 



fish, and even tlie sands of the Sahara have been fertilized by 

 artesian fountains. These achievements are more glorious than 

 the proudest triumphs of war, but, thus far, they give but faint 

 hope that we shall yet make full atonement for our spendthrift 

 waste of the bounties of nature.* 



Limits of Human Power. 



It is, on the one hand, rash and unphilosophical to attempt to 

 set limits to the ultimate power of man over inorganic nature, 

 and it is unprofitable, on the other, to speculate on what may be 

 accomphshed by the discovery of now unknown and unimagined 

 natural forces, or even by the invention of new arts and new 

 processes. But since we have seen aerostation, the motive power 

 of elastic vapors, the wonders of modern telegraphy, the destruc- 

 tive explosiveness of gunpowder, of nitro-glycerine, and even of 

 a substance so harmless, um-esisting and inert as cotton, there is 

 little in the way of mechanical achievement which seems hope- 

 lessly impossible, and it is hard to restrain the imagination from 

 wandering forward a couple oi generations to an epoch when our 

 descendants shall have advanced as far beyond us in physical con- 

 quest, as we have marched beyond the trophies erected by our 

 grandfathers. There are, nevertheless, in actual practice, limits 

 to the efiiciency of the forces which we are now able to bring into 

 the field, and we must admit that, for the present, the agencies 

 known to man and controlled by him are inadequate to the re- 

 ducing of great Alpine precipices to such slopes as would enable 

 them to support a vegetable clothing, or to the covering of large 

 extents of denuded rock with earth, and planting upon them a 

 forest growth. Yet among the mysteries which science is here- 

 after to reveal, there may be still undiscovered methods of ac- 

 complishing even grander wonders than these. Mechanical phi- 

 losophers have suggested the possibility of accumulating and 

 treasuring up for human use some of the greater natural forces, 



* The wonderful success which has attended the measures for subduing 

 torrents and preventing inundations employed in Southern France since 1865, 

 and described in Chapter III., post, ought to be here noticed as a splendid and 

 most encouraging example of well-directed effort in the way of physical resto. 

 ration. 



