CHAPTER IV 



SOIL-CARRIERS 



We have now seen by what means the rocks are 

 crumbled down; but in many cases much besides crum- 

 bhng is necessary to convert rock into good soil. Nearly 

 ail the soils which we look upon as especially fertile have 

 been made so by being mixed. 



When we consider which are the best corn-producing 

 regions of the earth, our thoughts naturally turn first to 

 Egypt, once the granary of the world. 



And what is Egypt? "The gift of the Nile," as the 

 ancient historian says. The soil which produces such 

 wonderful crops has not been produced by the decay of 

 the rocks upon which it rests, but is a mixture of soils 

 . brought in great part from the lofty mountains of Abys- 

 sinia, hundreds of miles away. The only fertile tracts in 

 Abyssinia itself are due to the sediment washed down 

 from these mountains, which are rich in the minerals most 

 desired by plants, but like the Cheviot Hills already men- 

 tioned, unproductive, owing to their height and the con- 

 sequently severe climate. 



The top of this magnificent chain of mountains is a 

 vast table-land, upon which the rains descend heavily and 

 incessantly during some three or four months of the year, 

 the fall being so abundant as to supply five tremendous 

 mountain-torrents, which rush down the sides of the 

 mountains with the force of cataracts, and carry with 



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