^unmllin0 tljvnirgb barioiis (Strata. 



By JOEL LEAN, Assoc. M. Inst. C.E. 

 Bead Dec. 20th, 1887. 



TUNNELLING, at tlie prosout day, is cliiefly associated 

 ill tlie ininds of people in connection witli railway 

 construction ; but railway engineers cannot take to tliom- 

 solves tlio credit of even having developed the art of 

 tunnelling. When the first railways were built, the 

 engineers went in largely for tunnelling, for instanc3 

 Kilsby Tunnel, on the L. & N. W. Railway, Box Tunnel, 

 on the G.W. Railway, and various others, as sharp curves 

 and steep gradients in those days were not considered 

 workable by locomotive engines, and therefore the necessity 

 arose of going through, instead of over or around, the 

 hilly obstacles. But they had the help of the experience 

 gained in canal tunnelling, and most of the men employed 

 in tunnelling in those days had worked on the construction 

 of the old canal tunnels; and to the canal engineers must 

 be given the credit of being the real pioneers of tunnelling, 

 at any rate in recent times. 



The autjior purposes giving examples of tunnels con- 

 structed through soft, or heavy ground, as it is called; 



147 



