The Conquest of the Desert 



The illuminating researches of these scientists 

 enable us more readily to understand the spon- 

 taneous and marvellous fertility of the lands 

 of South Africa which are bathed in sunshine. 



The germ life of arid lands is a subject worthy 

 of the attention of the universities of the Empire. 



The well-known term soil-mulch is deserving 

 of a brief notice. It may be defined as " any 

 material which is spread upon the soil to shade 

 the surface from the sun and to break the 

 connection between the water-bearing subsoil 

 and the exposed surface." Examples of mulch- 

 ing are familiar to everyone. Turn over a 

 board or stone lying on the ground, and you will 

 find that the soil beneath is moister than the 

 ground around it, since the pores of the earth, 

 or capillary channels, have been closed, and 

 the current of moisture passing upward to the 

 surface has been stopped. In the garden, leaves, 

 straw, and manure are commonly used. But 

 the most practical mulch is made of loose, dry 

 soil. This is done by frequently stirring the 

 surface of the ploughed lands with a harrow 

 or cultivator. The soil-mulch is also termed 

 the soil-blanket. 



Now the question arises : " How deep should 

 the soil-blanket be ? " The reply is : From two 



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