Page:On the economy of machinery and manufactures - Babbage - 1846.djvu/286

252 (307.) In the mines of Cornwall, almost the whole of the operations, both above and below ground, are contracted for. The manner of making the contract is nearly as follows. At the end of every two months, the work which it is proposed to carry on during the next period is marked out. It is of three kinds. 1. Tutwork, which consists in sinking shafts, driving levels, and making excavations: this is paid for by the fathom in depth, or in length, or by the cubic fathom. 2. Tribute, which is payment for raising and dressing the ore, by means of a certain part of its value when rendered merchantable. It is this mode of payment which produces such admirable effects. The miners, who are to be paid in proportion to the richness of the vein, and the quantity of metal extracted from it, naturally become quick-sighted in the discovery of ore, and in estimating its value; and it is their interest to avail themselves of every improvement that can bring it more cheaply to market. 3. Dressing. The "Tributors," who dig and dress the ore, can seldom afford to dress the coarser parts of what they raise, at their contract price; this portion, therefore, is again let out to other persons, who agree to dress it at an advanced price.

The lots of ore to be dressed, and the works to be carried on, having been marked out some days before, and having been examined by the men, a kind of auction is held by the captains of the mine, in which each lot is put up, and bid for by different gangs of men. The work is then offered, at a price usually below that bid at the auction, to the lowest bidder, who rarely declines it at the rate proposed. The tribute is a certain sum out of every twenty shillings