430 



Mr. Francis Fox 



[May 25, 



which are for double line of way, the permanent way being very 

 heavy, the rails weighing 100 lbs. to the yard. 



The altitude of the tunnel at its north portal is 3639 feet, and at 

 its south portal 3757 feet above the sea. A gallery of direction was 

 driven throughout, and the gradient of the rails is only such as to 

 provide for efficient drainage, viz. 5-82 per thousand, or about 1 

 in 172. 



The following table may be of interest, giving the result of in- 

 vestigations as to the cooling of the rocks. 



Temperature of the Rock in the St. Gothard Tunnel. 



Above are Centigrade. 



Although the works were carried on with energy, and with all 

 tho best appliances then known, the time occupied was ten years ; but 

 the most serious feature of the work was the heavy mortality amongst 

 the men : no less than 600 deaths occurred, including those of both the 

 Engineer and Contractor. 



From the experience then gained, great improvements have been 

 introduced into the works of the Simplon, as will be described later 

 on ; but the heavy loss of life in the St. Gothard was due to insuffi- 

 cient ventilation ; the high temperature ; the exposure of the men to 

 the Alpine climate after emerging from the tunnel ; the want of care 

 as to the changing of the men's wet mining clothes ; and the poor 

 character of the food with which the men supplied themselves. All 

 this has been greatly ameliorated, and even in English tunnels 

 certain improvements have been introduced, which were brought 

 from Switzerland. 



The traffic through tho tunnel has so largely increased that the 

 question of ventilation became of pressing importance, and the system 

 of Signor Saccardo, the well known Government Inspector of Kail- 

 ways and Engineer of Bologna, has been installed, which is an 

 ingenious application of the Injector system. One of the first intro- 

 ductions of this method was in the case of the Pracchia tunnel, on 



