felf is afterwards attacked by the affiftance of torches and lamps. For the day is foon loft, and the night continues as long as the work, that is, for feveral months. Before any great progrefs is made, great flaws appear in the earth, which falls in, and often crushes the poor miners to death; fo that, fays* Pliny, people are much more bold and venturous in fearching after pearls at the bottom of the waves in the Eaft, than in digging for gold in the bowels of the earth, which is become by our avarice more dangerous than the fea itself, It is therefore neceffary in thefe mines, as well as in the first I spoke of, to form good arches at proper diftances, to fupport the hollowed mountain. There are great rocks and veins of stone found alfo in these, which must be broke by fire and vinegar. But as the fmoke and steam would foon fuffocate the workmen, it is often more neceffary, and especially when the work is a little advanced, to break those enormous maffes with pick-axes and crows, and to cut away large pieces by degrees, which must be given from hand to hand, or from fhoulder to fhoulder, till thrown out of the mine. Day and night are paffed in this manner. Only the hindmoft workmen fee daylight; all the reft work by lamps. If the rock is found to be too long, or too thick, they proceed on the fide, and carry on the work in a curve line. When the work is finifhed, and the fubterraneous paffages carried their proper length, they cut away the props of the arches, that *Ut jam minùs temera- to nocentiores fecimus terras. rium videatur e profundo Plin. maris petere margaritas : tan had had been formed at due diftances from each other. This is the ufual fignal of the ruin which is to follow, and which those who are placed to watch it, perceive first, by the finking in of the mountain, which begins to shake: upon which they immédiately, either by hallowing, or beating upon a brazen instrument, give notice to the workmen to take care of themselves, and run away the first for their own fafety. The mountain, fapped on all fides in this manner, falls upon itself, and breaks to pieces with a dreadful noife. The * victorious workmen then enjoy the fight of nature overturned. The gold, however, is not yet found; and when they began to pierce the hill, they did not know whether there was any in it. Hope and avarice were fufficient motives for undertaking the labour, and confronting such dangers. But this is only the prelude to new toils, ftill greater and more heavy than the firft. For the waters of the higher neighbouring mountains must be carried through very long trenches, in order to its being poured with impetuofity upon the ruins they have formed, and to carry off the precious metal. For this purpofe new canals must be made, fometimes higher or lower according to the ground, and hence the greatest part of the labour arifes. For the level must be well placed, and the heights well taken in all the places, over which the torrent is to pafs to the lower mountain, that has been thrown down; in order that the water may have fufficient force to tear away the gold *Spectant victores ruinam naturæ: nec tamen ad huc aurum eft. Plin. lapide. A centefimo plerumque Z4 wherever wherever it paffes, which obliges them to make it fall from the greatest height they can. And as to the inequality of the ground in its course, they remedy that by artificial canals, which preferve the defcent, and keep the keep the water within their bounds. And if there are any large rocks, which oppofe its paffage, they muft be hewn down, made level, and have tracks cut in them for the wood-work, which is to receive and continue the canal. Having united the waters of the highest neighbouring mountains, from whence they are to fall, they make great refervoirs, of the breadth of two hundred, and the depth of ten, feet. They generally leave five openings of three or four feet fquare, to receive the water at feveral places. After which, when the refervoirs are full, they open the fluice, from whence falls fo violent and impetuous a torrent, that it carries away all before it, and even stones of confiderable magnitude. There is another work in the plain at the foot of the mine. New trenches must be dug there, which form feveral beds for the falling of the torrent from height to height, till it dif charges itself into the fea. But to prevent the gold from being carried off with the current, they lay, at proper diftances, good dams of Ulex, a fort of fhrub much resembling our rofemary, but fomething thicker of leaves, and confequently fitter for catching this prey as in nets. Add to this, that good planks are ne-, ceffary on each fide of these trenches, to keep the water within them; and where there are any dangerous inequalities of ground,these new canals must be supported with * fhores, till the torrent *Machines to fupport thofe canals made of board. lofes lofes itself at laft in the fand of the ocean, in the neighbourhood of which the mines commonly are. The gold got in this manner at the feet of mountains, has no need of being purified by fire; for it is at first what it ought to be. It is found in lumps of different bignefs, as it is alfo in deep mines, but not fo commonly. As to the wild rosemary branches used on this occafion, they are taken up with care, dryed, and then burnt; after this the afhes are washed on the turf, upon which the gold falls, and is easily gathered. Pliny examines wherefore gold is preferred Plin. 1. 33. to other metals, and gives feveral reafons c. 3. for it. It is the only metal, which lofes nothing, or almost nothing by the fire, not even of funeral piles, or conflagrations, in which the flames. are generally moft violent. It is even affirmed to be rather the better for having paft the fire several times. It is by fire also that proof is made of it; for when it is good, it takes its colour from it. This the workmen call obryzum, refined gold. What is wonderful in this proof, is, that the hotteft charcoal has no effect in it to melt it, * a clear fire of ftraw is neceffary, with a little lead thrown in to refine it. Gold lofes very little by ufe, and much less than any other metal whereas filver, copper, and pewter, foil the hands, and draw black Strabo makes the fame remark, and gives the reafon for this effect. Paleâ faciliùs liquefit aurum: quia flamma mollis cum fit, proportionem habet temperatam ad id quod cedit & facile funditur; car. lines upon any thing, which is a proof that they wafte, and lose their substance more easily. It is the only metal that contracts no ruft, nor any thing which changes its beauty, or diminishes its weight. It is a thing well worthy of admiration, that of all fubftances gold preferves itself best, and entire, without ruft or dirt, in water, the earth, dung, and fepulchres, and that throughout all ages. There are medals in being which have been struck above two thousand years, which feem just come from the workman's hands. It is obferved, that gold refifts the impres fions and corrofion of falt and vinegar, which melt and fubdue all other matter. There is no metal which extends better, nor divides into fo great a number of particles of different kinds. An ounce of gold, for inftance, will form feven hundred and fifty leaves, each leaf of four inches fquare and upwards. What Pliny fays here, is certainly very wonderful; but we fhall prefently fee, that our modern artificers have carried their skill much farther than the antients in this, as well as many other points. In fine, gold will admit to be spun and wove like wool into any form. It may be worked even without wool, (or filk) or with both. The firft of the Tarquins triumphed in a veft of cloth made of gold; and Agrippina, the mother of Nero, when the emperor Claudius her husband gave the people the reprefentation of a fea-fight, appeared at it in a long Jam contra falis & aceti fuccos, domitores rerum,conftantia. Plin. Nec alius laxius dilatatur, aut numerofius dividi tur, utpote cujus unciæ in feptingenas & quinquagenas, plurefque bracteas, quaternûm utroque digitorum, fpargantur. Plin. robe |