MINING. 317 



239. Shafts. Shafts are used in prospecting, and also in 

 mining, where the claims are deep and cannot be reached by 

 either the hydraulic process or the tunnel. The prospecting 

 shaft is sometimes sunk into hills supposed to be auriferous, 

 where the shaft is far less expensive than the tunnel. After 

 the shaft demonstrates that the dirt is rich, and precisely the 

 altitude at which it lies, a tunnel is cut to strike it. The shaft 

 may be the cheaper for prospecting, but the tunnel is usually 

 the cheaper if any large amount of dirt is to be taken out. 



The shaft is dug by one man in the hole, and one or two 

 are employed at a windlass in hauling up the dirt. Mining 

 shafts in placer diggings are rarely over one hundred feet 

 deep ; but one was dug in Trinity County to the depth of six 

 hundred feet, for the purpose of prospecting. It found neither 

 pay-dirt nor the bed-rock. 



240. River Mining. River mining is mining for gold m 

 the beds of rivers, below low- water mark. The only practi- 

 cable method of doing this is by damming the stream, and 

 taking the water out of its bed in a ditch or flume. It has 

 been proposed by persons who never saw the mines, to get the 

 gold by dredging, or with a diving-bell ; but such schemes are 

 absurd in the eyes of miners. The rivers in which the gold is 

 found are mountain-torrents, in which a canoe can scarcely 

 float in summer, much less a dredging-machine ; and any 

 large scoop working under water woul(J0niiss the crevices and 

 corners in the rocks, where most of the gold is found. As the 

 water is very seldom more than a couple of feet deep, a diving- 

 bell would be of little service. The flume, the ditch, and the 

 wing-dam are the chief tasks of the river-miner. The ditch is 

 rarely used, because the banks of the mining-streams are 

 usually so steep, high, rocky, and crooked, that a flume is 

 cheaper. The wing-dam is not often used, because the river- 

 beds are in most places too narrow. The flume is almost uni- 

 versally employed. 



241. Beach Mining. Beach mining is the business of 

 washing the sands of the ocean-beach. Between Point Men- 



