ERECTION OF THE GOKTEIK BRIDGE. 615 



fastened to tiieni and the traveler moved forward. Then the material 

 was loaded on Hat ears, pushed out upon the bridge, and transferred 

 from the ears into position. 



Owing to the height of the bridge and the extreme cnanges in tem- 

 perature careful provision had to be made both for the wind pressure 

 and the unusual contraction and expansion of the metal. The bridge 

 was built to carry a load of 2,2-iO pounds to each linear foot of track, 

 in addition to two locomotives, each weighing 54 tons. It is to with- 

 stand a wind pressure of about 3-i pounds per square foot when a train 

 is upon it, and about 56 pounds per square foot at other times. These 

 calculations were made by the consulting engineers of the railwa}' 

 company — Messrs. Sir Alexander Rendel & Co., of London, repre- 

 sented by Mr. W. H. Clark. The viaduct was erected under the 

 supervision of Mr. D. Duchars, chief engineer, and Mr. J. A. White, 

 resident engineer. 



As already stated, a portion of the viaduct is located upon a natural 

 bridge. This is a rocky formation which is just wide enough to safeh'^ 

 support the towers. Two hundred feet below its summit flows a river 

 which has forced a channel l)eneath the formation, so that the total 

 height of the bridge above the water is 52U feet. 



