Tunnels and Their Making 45 



been attempted in Britain. Huge pumping 

 engines are constantly employed in keeping 

 the tunnel free from water, but there has 

 been no really serious trouble, and both 

 expresses and goods trains are constantly 

 passing through it. 



The amount of water pumped up 

 from the Severn tunnel each day would 

 supply a fair-sized town with all its 

 needs. 



The task of boring such a tunnel as this 

 would be much easier to-day owing to the 

 increased use of electricity. 



The Kilsby and the Severn are the greatest 

 of the English tunnels, though the former 

 is exceeded in length by several. But they 

 are greatest in achievement and the con- 

 quering of obstacles which at one period 

 seemed insurmountable. 



To-day tunnelling is becoming more or less 

 commonplace because we are so used to the 

 successful cutting of tubes for London's 

 underground railways. Here tunnelling has 

 really been brought to a fine art by the 

 employment of simple yet very effective 



