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ON MINES. The following is the account of the mines in the district of Minas Geraes, and the method of working them, in Mr. Mounteney's new work upon South America "The first gold which is certainly known to have been produced in Minas Geraes, was a sam- ple of three oitavas, presented in 1695 to the Capt. Mar of Espirito Santo, by Antonio Rodriguez Arzain, a native of the town of Taboate, since which period it has been discovered in all the districts of which the captaincy is composed. The news of gold having been found in Minas Geraes soon attracted there a great number of of Paulistas and Europeans. It was, however, in 1703, that the principal influx of adventurers to the mines took place: meanwhile, discoveries of gold continued to be made. In 17L4, one piece of native gold was found. which was worth 700 milreis ("nearly £ '200.). Three others of nearly the same size, and one of the value of 3000 crusados (-^300.) were also about this period dug from the earth, although the latter had the dis- advantage of lying deep. At the commencement of the mining system in the Brazils, the common method of proceeding- was to open a square pit, which the workmen called cata, till they came to the cascalho; this they broke up with pick-axes, and placing it in a batea, a wooden vessel, broad at the top and nar- row at the bottom, exposed it to the action of run- ning water, shaking it from side to side till the earth was washed away, and the metallic particles had all subsided. Lumps of native gold were often found from twenty to one hundred oilavas in weight; a few which weighed from two to three- hundred, and one, itis asserted, of thirteen pounds; but these were insulate;! pieces.and the ground j where they were discovered was not rich. All the first workings were in the beds of rivers, or in the taboleire.s, the table-ground on their sides. In I72i«, the method of mining had undergone a considerable alteration, introduced by some natives of the northern country; instead of opening- catas, or searching-places, by hand, and carrying the cascalho thence to the water, the mi lers conducted water to the miningground, and, washing away the mould, broke up the cascalho in pits under a fall of the water, or exposed it to the same action in wooden troughs; a uu thus a great expense of human labour was spared. At the commencement ofthe present century, there was a general complaint in Minas Geraes, that the ground was exhausted of its gold yet it was the opinion of all scientific men, and still continues to be so, that hitherto only the surface of the earth had been scratched, and that the veins are for the most part untouched. The mining was either in the beds of the streams or in the mountains; in process of time the rivers had changed their beds; the miners discovered that the primary beds were above the present level, and these they called ffuaparas; the next step is the laholeira, which seems to be close by the side of the veio, or present body of the stream. All these are mining-grounds the'first is easily worked, because little or no waters remain there the surface had only to be removed, and then the cascalho was found. In the second step, wheels were often required to draw off the water; the present bed could only be'worked by making a new cut, which is calied lalo, and diverting the stream, and, even when this is done. the wheel is still wanting. The wheel was a clumsy machine, which it was frequently necessary to remove, and fifty slaves or more were employed a whole day in removing it. This was the only means in use for saving human labour, for not even a cart or hand-barrow was to be seen the rubbish and the cascalho were all carried iij troughs upon the heads of slaves, who had in many instances to climb up steep asoents, where inclined planes might have been formed with very little trouble, and employed with great advantage. River mining, however, was the easiest and most effectually performed it was, therefore, the commonest. But the greater part of those streams which were known to be auriferous had been wrought. The mountains were more tempt- ing, but required much greater labour: a few bracas, if the veins were good, enriched the ad- venturers for ever, and in the early days of the mines, the high grounds attracted men who were more enterprising and persevering than their des- cendants. The mode of working in such ground is not by excavation, but by what is called talho alberto, the open etit.-laying the vein bare by clearing away the surface. This labour is im- mense, if water cannot be brought to act upon the spot; and, when even there is water, it is not always easy to direct it, nor will the nature of the cut allow always of its use. When tlit-, miners found no cascalho in the mountains, they suspect- ed that the stones might contain gold, and they were not deceived in this supposition. This is the most difficult mode of extractidn the stones were broken by manual labour, withiron mallets in a few instances only, one machine was worked by slaves, instead of cattle. The modes of mining having been so imper- fect, it has not unreasonably been concluded, that now, when more scientific means are about being adopted, BrazH is likely to yield a greater quan- tity of gold than at any former time."