It is not uncommon for two companies, owning adjacent claims in a hill, to unite and cut a tunnel on joint account along the dividing line. They go in until they reach the pay-dirt, and then a surveyor is employed to run the line between their claims, and the tunnel is continued through the pay-dirt. The dirt from the tunnel is washed for the joint account of the two companies. After the dividing line has been established, each company keeps on its own side, and each has its time to use the tram-way. They may also have a joint-stock sluice at the mouth of the tunnel--one company having the privilege of using the sluice one week, and the other the next. All the dirt brought out in a week can readily be washed in a day. The work of taking out the pay-dirt after the main tunnel has been cut, is called "drifting;" and the holes made by the men engaged in it are termed "drifts." The drifts are usually not so high as the tunnels. The large stones and barren dirt obtained in the drifts are piled up here and there to sustain the earth overhead. Sometimes wooden posts are likewise necessary. _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, but it found neither pay-dirt nor the bed-rock.