1873.] 



167 



[Lesley. 



or 6 feet 6 inches high, regulated by the height of the cars used ; a shoot 

 by which to deliver the ore into them to be provided. This gang road 

 should have a series of "bolt holes" (places of refuge) cut for men to 

 escape into when meeting the cars, and it will be necessary to well 

 timber this road, the dimensions given being those clear of the timbers. 

 On the rise side an opening head will be made parallel and immediately 

 contiguous to it, both being extended just so far as it is intended to work 

 the ore, it may be 1,000 or any number of feet regulated by the nature 

 and the local uniformity of the measures, and the limit of economy in 

 haulage and ventilation. The mouth of the gang road may either be at 

 one end of the work, or it may be in the centre of it, receiving cars from 

 right and left. 



The opening head, as it is driven, will be divided into "banks" of say 

 33 or 40 feet long on the face, which banks will be mined to the rise, 

 the ore being put down a road left in the centre by the gob being built 

 up on either side, and supporting the roof, as shown in the diagram 

 below. Ventilation being provided for by staples (small shafts) being 



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sunk from the surface, or by drifts put up in the ore ; when that does 

 not crop out on the surface, both will be needed. 



With dips of less inclination, wider banks may be worked, the ore 

 being run to the gang road by self-acting inclines. 



While it is not easy to define beforehand with preciseness, what will 

 be the action of any group of strata, the foregoing is a general description 

 of the methods I believe best to be adopted in the mining of these ores. 

 Of necessity contingencies will present themselves, which can only be 



