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Gold Mines of Georgia. 



or forty feet. . In working a shaft, in the decomposing rocks, or in 

 clay, it will be requisite to curb them in a substantial manner with 

 wood, as the work is sufficiently laborious and discouraging, without 

 adding the risk of life. The roof of a tunnel should be stanchioned 

 as the workmen proceed, and the number of stanchions, will depend 

 on the consistency of the rock in which the excavation is made, and 

 are never to be omitted, although it be in granite, for there are so 

 many fissures in these rocks, that there is always danger to be avoid- 

 ed, by using the precautionary measures, adopted for those of a worse 

 appearance. 



Fig. 15, exhibits a method of stanchioning a tunnel, recommended 



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