266 EESOUECES OP CALIFORNIA. 



pay-dirt is very convenient, two men can shOvel enough to 

 keep the machine in operation. The Burke rocker was exten- 

 sively used in CalifoiTiia eight and ten years ago, but now it is 

 a great rarity. 



§ ]97. Timnd-Mining. — A tunnel, in Califomian mining, is 

 an adit or drift entering a hill-side, or running out from a shaft. 

 Mining-tunnels are usually nearly horizontal — those entering 

 hill-sides having a slight ascent, for the double purpose of 

 draining the mine, and to facilitate the removal of the pay- 

 dirt. In a few hills the tunnels run downward at an angle of 

 twenty degrees or more, to avoid veins or ledges of rock, 

 which would have to be blasted through if the tunnel were 

 cut horizontally ; but this can only be done with safety in hills 

 which are drained by older horizontal tunnels. 



The mining-tunnel does not nm through a hill, but only into 

 it. The length of tunnels varies greatly ; the longest are about 

 a mile. The usual height is seven feet, the width five feet. 

 Ordinarily the top must be supported by timbers, to prevent 

 it from flilling in, and not unfrequently the sides must also be 

 protected by boards. The cost of cutting a tunnel varies from 

 two to forty dollars a longitudinal foot, according to the nature 

 of the ground, the cost of getting timbers, &c. Tunnels are 

 usually made by companies of eight or ten men, of whom one- 

 half may be merchants, lawyers, physicians, or office-holders, 

 and the remainder laboring miners. The latter class do the 

 work ; the former furnish provisions and tools, and a certain 

 amount of cash weekly until the pay-dirt is reached. Two or 

 three men work at a time cutting a tunnel ; one or two to dig 

 the dirt ; and one or two to haul it out. The dirt of the first 

 fifty yards is hauled out in a wheelbarrow ; beyond that dis- 

 tance a httle tram-way or railroad is laid down, and the dirt is 

 hauled out in cars, pushed by the miners. It is not customary 

 to use horses. It is common to have two relays of laborers — 

 one set working from noon to midnight, the other from mid- 

 night to noon. Work in a tunnel is as pleasant at night as in 

 the da^^inie. When a company is rich, or has many laborers, it 



