VJ ADDRSSS. 



and Africa, is probably incurable by any means that 

 will ever be in the power of man. If we could first 

 make the rain descend, where there is no roughness 

 or variety of surface, and no vegetation, to disturb 

 the equilibrium of the atmosphere, and none of the 

 geographical conditions on which showers depend, 

 vegetation would doubtless gradually encroach upon 

 the arid waste. Or if we could first produce vegeta- 

 tion where there is no rain to water the parched ground, 

 then the fertilizing showers would, no doubt, by an 

 atmospheric law, in due time descend. But since we 

 can command neither of these, we may as well regard 

 those great deserts of the Eastern Continent as irre- 

 trievably doomed to perpetual unproductiveness. The 

 great belt of barren sand which stretches across the 

 northern part of Africa, and the centre of Asia, com- 

 prises about 6,500,000 square miles. Adding to this 

 the aggregate of smaller tracts of land equally, or almost 

 equally sterile, we have a total of about one-seventh of 

 land surface of the globe which cannot be made to yield 

 any tribute to human life or human luxury. The pro- 

 portion is remarkable. As one-seventh of time is 

 morally excepted from the term of human labor, so one- 

 seventh of the ground is naturally excepted from the 

 field of human industry, enjoying a grand and solemn 

 Sabbath stillness. 



A second aspect in which the productive power of 

 the earth may be considered, is with reference to 

 improved modes of cultivation. It is impossible to fix 

 a limit to the extent to which science and labor may 

 increase the products of the soil. We see a vast 

 difference in this respect between different countries 



