1900.] 



on the Great Alpine Tunnels 



DEPTH FOR rC 



429 



Metres 3000 



soo 

 800 



700 . 



eoo 

 soo . 

 too 

 xo . 



200 



100 



zooo . 



900 

 800 

 700 

 600 

 600 

 ICO 

 300 

 ZOO 



too . 



tOOO 

 900. 

 SOO . 

 700 



eoo i 



10 20 30 



go to eo'Motre* 



MAXIMUM HEIGHT OP 

 THE MOUNTAIH ABOVE 

 THE SIMPLOH TUNNEL 



MONT CENI3 ffi 

 /3S3Hteira> / £ 



'i 



COTHARD i 



7J 



J* 



ARLBERC 



l3IOHeires 



SIMPLOH 

 V05 Metres 



Fig. 5. — Curves showing Depths corresponding to an Increase in Temperature 

 of 1° C. for the Mont Cenis, Gothard, and Arlberg Tunnels (with curve of 

 probable temperature for the Simplon Tunnel). 



