362 



WOOD TRANSPORT BY WATER. 



most highly perfected of all dams, and are used in the 

 Bavarian forest, as shown in transverse section, in Fig. 234. 

 The masonry rests on a foundation of piles, and the reservoir 

 side of the dam is faced with hewn stones resting on cemented 

 rubble-masonry containing a thin layer of concrete. A wall 

 of cement and clay bounds this structure, and a well-stamped 



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Fiir. 284. Masonry and earthen dam in Bavaria. 



earth-dam is continued towards the valley. This mode of 

 construction, and a liberal use of cement and concrete to a 

 considerable depth in the foundations of the dam, make it 

 watertight in the highest possible degree. 



(e) Sluice-gates. The gates for the chief outlet of water 

 from the reservoir are usually in the middle of the dam, but 

 sometimes at its base. The sluice-gates open usually into a 



