De Re Metallica, Translated from the First Latin Edition of 1556

by Georg Agricola

When anyone, in an endeavour to increase his fortune, meets the expenditure of a mine alone, it is of great importance that he should attend to his works and personally superintend everything that he has ordered to be done. For this reason, he should either have his dwelling at the mine, where he may always be in sight of the workmen and always take care that none neglect their duties, or else he should live in the neighbourhood, so that he may frequently inspect his mining works. Then he may send word by a messenger to the workmen that he is coming more frequently than he really intends to come, and so either by his arrival or by the intimation of it, he so frightens the workmen that none of them perform their duties otherwise than diligently. When he inspects the mines he should praise the diligent workmen and occasionally give them rewards, that they and the others may become more zealous in their duties; on the other hand, he should rebuke the idle and discharge some of them from the mines and substitute industrious men in their places. Indeed, the owner should frequently remain for days and nights in the mine, which, in truth, is no habitation for the idle and luxurious; it is important that the owner who is diligent in increasing his wealth, should frequently himself descend into the mine, and devote some time to the study of the nature of the veins and stringers, and should observe and consider all the methods of working, both inside and outside the mine. Nor is this all he ought to do, for sometimes he should undertake actual labour, not thereby demeaning himself, but in order to encourage his workmen by his own diligence, and to teach them their art; for that mine is well conducted in which not only the foreman, but also the owner himself, gives instruction as to what ought to be done. A certain barbarian, according to Xenophon, rightly remarked to the King of Persia that "the eye of the master feeds the horse,"[2] for the master's watchfulness in all things is of the utmost importance.

When several share together the expenditure on a mine, it is convenient and useful to elect from amongst their own number a mine captain, and also a foreman. For, since men often look after their own interests but neglect those of others, they cannot in this case take care of their own without at the same time looking after the interests of the others, neither can they neglect the interests of the others without neglecting their own. But if no man amongst them be willing or able to undertake and sustain the burdens of these offices, it will be to the common interest to place them in the hands of most diligent men. Formerly indeed, these things were looked after by the mining prefect[3], because the owners were kings, as Priam, who owned the gold mines round Abydos, or as Midas, who was the owner of those situated in Mount Bermius, or as Gyges, or as Alyattes, or as Crœsus, who was the owner of those mines near a deserted town between Atarnea and Pergamum[4]; sometimes the mines belonged to a Republic, as, for instance, the prosperous silver mines in Spain which belonged to Carthage[5]; sometimes they were the property of great and illustrious families, as were the Athenian mines in Mount Laurion[6].

When a man owns mines but is ignorant of the art of mining, then it is advisable that he should share in common with others the expenses, not of one only, but of several mines. When one man alone meets the expense for a long time of a whole mine, if good fortune bestows on him a vein abundant in metals, or in other products, he becomes very wealthy; if, on the contrary, the mine is poor and barren, in time he will lose everything which he has expended on it. But the man who, in common with others, has laid out his money on several mines in a region renowned for its wealth of metals, rarely spends it in vain, for fortune usually responds to his hopes in part. For when out of twelve veins in which he has a joint interest one yields an abundance of metals, it not only gives back to the owner the money he has spent, but also gives a profit besides; certainly there will be for him rich and profitable mining, if of the whole number, three, or four, or more veins should yield metal. Very similar to this is the advice which Xenophon gave to the Athenians when they wished to prospect for new veins of silver without suffering loss. "There are," he said, "ten tribes of Athenians; if, therefore, the State assigned an equal number of slaves to each tribe, and the tribes participated equally in all the new veins, undoubtedly by this method, if a rich vein of silver were found by one tribe, whatever profit were made from it would assuredly be shared by the whole number. And if two, three, or four tribes, or even half the whole number find veins, their works would then become more profitable; and it is not probable that the work of all the tribes will be disappointing."[7] Although this advice of Xenophon is full of prudence, there is no opportunity for it except in free and wealthy States; for those people who are under the authority of kings and princes, or are kept in subjection by tyranny, do not dare, without permission, to incur such expenditure; those who are endowed with little wealth and resources cannot do so on account of insufficient funds. Moreover, amongst our race it is not customary for Republics to have slaves whom they can hire out for the benefit of the people[8]; but, instead, nowadays those who are in authority administer the funds for mining in the name of the State, not unlike private individuals.

Some owners prefer to buy shares[9] in mines abounding in metals, rather than to be troubled themselves to search for the veins; these men employ an easier and less uncertain method of increasing their property. Although their hopes in the shares of one or another mine may be frustrated, the buyers of shares should not abandon the rest of the mines, for all the money expended will be recovered with interest from some other mine. They should not buy only high priced shares in those mines producing metals, nor should they buy too many in neighbouring mines where metal has not yet been found, lest, should fortune not respond, they may be exhausted by their losses and have nothing with which they may meet their expenses or buy other shares which may replace their losses. This calamity overtakes those who wish to grow suddenly rich from mines, and instead, they become very much poorer than before. So then, in the buying of shares, as in other matters, there should be a certain limit of expenditure which miners should set themselves, lest blinded by the desire for excessive wealth, they throw all their money away. Moreover, a prudent owner, before he buys shares, ought to go to the mine and carefully examine the nature of the vein, for it is very important that he should be on his guard lest fraudulent sellers of shares should deceive him. Investors in shares may perhaps become less wealthy, but they are more certain of some gain than those who mine for metals at their own expense, as they are more cautious in trusting to fortune. Neither ought miners to be altogether distrustful of fortune, as we see some are, who as soon as the shares of any mine begin to go up in value, sell them, on which account they seldom obtain even moderate wealth. There are some people who wash over the dumps from exhausted and abandoned mines, and those dumps which are derived from the drains of tunnels; and others who smelt the old slags; from all of which they make an ample return.

Now a miner, before he begins to mine the veins, must consider seven things, namely:—the situation, the conditions, the water, the roads, the climate, the right of ownership, and the neighbours. There are four kinds of situations—mountain, hill, valley, and plain. Of these four, the first two are the most easily mined, because in them tunnels can be driven to drain off the water, which often makes mining operations very laborious, if it does not stop them altogether. The last two kinds of ground are more troublesome, especially because tunnels cannot be driven in such places. Nevertheless, a prudent miner considers all these four sorts of localities in the region in which he happens to be, and he searches for veins in those places where some torrent or other agency has removed and swept the soil away; yet he need not prospect everywhere, but since there is a great variety, both in mountains and in the three other kinds of localities, he always selects from them those which will give him the best chance of obtaining wealth.

In the first place, mountains differ greatly in position, some being situated in even and level plains, while others are found in broken and elevated regions, and others again seem to be piled up, one mountain upon another. The wise miner does not mine in mountains which are situated on open plains, neither does he dig in those which are placed on the summits of mountainous regions, unless by some chance the veins in those mountains have been denuded of their surface covering, and abounding in metals and other products, are exposed plainly to his notice,—for with regard to what I have already said more than once, and though I never repeat it again, I wish to emphasize this exception as to the localities which should not be selected. All districts do not possess a great number of mountains crowded together; some have but one, others two, others three, or perhaps a few more. In some places there are plains lying between them; in others the mountains are joined together or separated only by narrow valleys. The miner should not dig in those solitary mountains, dispersed through the plains and open regions, but only in those which are connected and joined with others. Then again, since mountains differ in size, some being very large, others of medium height, and others more like hills than mountains, the miner rarely digs in the largest or the smallest of them, but generally only in those of medium size. Moreover, mountains have a great variety of shapes; for with some the slopes rise gradually, while others, on the contrary, are all precipitous; in some others the slopes are gradual on one side, and on the other sides precipitous; some are drawn out in length; some are gently curved; others assume different shapes. But the miner may dig in all parts of them, except where there are precipices, and he should not neglect even these latter if metallic veins are exposed before his eyes. There are just as great differences in hills as there are in mountains, yet the miner does not dig except in those situated in mountainous districts, and even very rarely in those. It is however very little to be wondered at that the hill in the Island of Lemnos was excavated, for the whole is of a reddish-yellow colour, which furnishes for the inhabitants that valuable clay so especially beneficial to mankind[10]. In like manner, other hills are excavated if chalk or other varieties of earth are exposed, but these are not prospected for.

There are likewise many varieties of valleys and plains. One kind is enclosed on the sides with its outlet and entrance open; another has either its entrance or its outlet open and the rest of it is closed in; both of these are properly called valleys. There is a third variety which is surrounded on all sides by mountains, and these are called convalles. Some valleys again, have recesses, and others have none; one is wide, another narrow; one is long, another short; yet another kind is not higher than the neighbouring plain, and others are lower than the surrounding flat country. But the miner does not dig in those surrounded on all sides by mountains, nor in those that are open, unless there be a low plain close at hand, or unless a vein of metal descending from the mountains should extend into the valley. Plains differ from one another, one being situated at low elevation, and others higher, one being level and another with a slight incline. The miner should never excavate the low-lying plain, nor one which is perfectly level, unless it be in some mountain, and rarely should he mine in the other kinds of plains.

With regard to the conditions of the locality the miner should not contemplate mining without considering whether the place be covered with trees or is bare. If it be a wooded place, he who digs there has this advantage, besides others, that there will be an abundant supply of wood for his underground timbering, his machinery, buildings, smelting, and other necessities. If there is no forest he should not mine there unless there is a river near, by which he can carry down the timber. Yet wherever there is a hope that pure gold or gems may be found, the ground can be turned up, even though there is no forest, because the gems need only to be polished and the gold to be purified. Therefore the inhabitants of hot regions obtain these substances from rough and sandy places, where sometimes there are not even shrubs, much less woods.

The miner should next consider the locality, as to whether it has a perpetual supply of running water, or whether it is always devoid of water except when a torrent supplied by rains flows down from the summits of the mountains. The place that Nature has provided with a river or stream can be made serviceable for many things; for water will never be wanting and can be carried through wooden pipes to baths in dwelling-houses; it may be carried to the works, where the metals are smelted; and finally, if the conditions of the place will allow it, the water can be diverted into the tunnels, so that it may turn the underground machinery. Yet on the other hand, to convey a constant supply of water by artificial means to mines where Nature has denied it access, or to convey the ore to the stream, increases the expense greatly, in proportion to the distance the mines are away from the river.