VERTICAL FARMING 



39 



the harmful spoil pile or bank, scattering the dirt over the 

 adjoining land for a distance of over a hundred feet. 



A BEAUTIFUL I5I.ASTHI) DITCH 



Ditch blasting is by no means limited to wet lands, for it is 

 being successfully used in excavating even in dry hill soil, pro- 

 vided it is not sandy. Changes in the soil or the soil condition 

 require changes in the selection of the explosive and the method 

 of loading, which are details that can best be learned from the 

 books of practical instruction of the manufacturer or from one 

 of their representatives. 



The use of blasting in connection with drainage is not limited 

 to the shattering of deep drainage courses jto permit of down- 

 ward drainage, but is being used largely in connection with 

 open and blind ditches where the subsoil is so hard that it pre- 

 vents the passage of the water into the drainage channels. 



