DISTRIBUTION OF RAINS. 141 



to the Andes charged with the vapor of the southern Atlantic are 

 robbed of their moisture on the eastern side of the mountains, and 

 hence when they pass over to the western side, they are dry 

 winds, and no rain can fall. The same conditions do not exist in 

 the case of Sahara. There is no mountain wall shutting it in. 

 Vapor-freighted winds reach that region, but it is a desert in con- 

 sequence of the character of its soil. Made up largely of sand 

 and rocks, it becomes very highly heated. The thermometer rises 

 in certain parts of Sahara to 169°, and the currents of air that rise 

 over that region are of so high a temperature that when vapor- 

 laden clouds come over it their temperature is raised, and they are 

 at once dissipated. 



There are other portions of the globe not completely desert, 

 which are visited by but very little rain. The central part of 

 Australia, the central part of southern Africa, Central America, 

 Mexico, and that portion of the United States included between 

 the Sierra Nevada and the Rocky mountains, for reasons which 

 have been assigned, receive but very little moisture. In view of 

 what has been presented, the following questions naturally suggest 

 themselves : Will the character of these desert regions ever be 

 changed ? Can they be changed ? Is it in the power of man to 

 do it ? It may be answered as regards the desert region north of 

 the Himalayas, that it seems doomed to perpetual barrenness. 

 Sterility has been written upon it by the finger of the Almighty. 

 He has reared those lofty mountain summits as perpetual tt)kens 

 of His will, and by them. He says, " Thus far can the storm clouds 

 come, but here shall their course be stayed. Down these southern 

 slopes they shall pour their burden of rain forever." The same 

 may be answered in regard to the desert of Atacama. There the 

 Andes rise as perpetual monuments of God's eternal design, and 

 iherewWl the vapor-loaded clouds be stayed, and down the eastern 

 slopes will be poured their treasures of rain, while their western 

 slope must forever remain parched, barren and desolate. But is it 

 so in regard to Sahara ? We find that God has not raised any- 

 high mountain barrier around this region. The same physical 

 reasons for the condition of desert do not exist here as exist in the 

 case of the others. This region is visited by vapor-charged winds, 

 and if the condition of the surface can be essentially changed, is 

 there any good reason why that whole region may not one day be 

 one of fertility ? But how can this be done? lam unable to 

 answer. We know, however, that trees may grow upon that 



