De Re Metallica, Translated from the First Latin Edition of 1556
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END OF BOOK I.
FOOTNOTES:
[Pg 1][1] Fibrae—"fibres." See Note 6, p.70
[2] Commissurae saxorum—"rock joints," "seams," or "cracks." Agricola and all of the old authors laid a wholly unwarranted geologic value on these phenomena. See description and footnotes, Book III. , pages 43 and 72
[3] Succi—"juice," or succi concreti—"solidified juice." Ger. Trans. , saffte. The old English translators and mineralogists often use the word juices in the same sense, and we have adopted it. The words "solutions" and "salts" convey a chemical significance not warranted by the state of knowledge in Agricola's time. Instances of the former use of this word may be seen in Barba's "First Book of the Art of Metals," (Trans. Earl Sandwich, London, 1674, p. 2, etc.,) and in Pryce's Mineralogia Cornubiensis (London, 1778, p. 25, 32).
[4] In order that the reader should be able to grasp the author's point of view as to his divisions of the Mineral Kingdom, we introduce here his own statement from De Natura Fossilium, (p. 180). It is also desirable to read the footnote on his theory of ore-deposits on pages 43 to 53, and the review of De Natura Fossilium given in the Appendix.
"The subterranean inanimate bodies are divided into two classes, one of which, because it is a fluid or an exhalation, is called by those names, and the other class is called the minerals. Mineral bodies are solidified from particles of the same substance, such as pure gold, each particle of which is gold, or they are of different substances such as lumps which consist of earth, stone, and metal; these latter may be separated into earth, stone and metal, and therefore the first is not a mixture while the last is called a mixture. The first are again divided into simple and compound minerals. The simple minerals are of four classes, namely earths, solidified juices, stones and metals, while the mineral compounds are of many sorts, as I shall explain later.
"Earth is a simple mineral body which may be kneaded in the hands when moistened, or from which lute is made when it has been wetted. Earth, properly so called, is found enclosed in veins or veinlets, or frequently on the surface in fields and meadows. This definition is a general one. The harder earth, although moistened by water, does not at once become lute, but does turn into lute if it remains in water for some time. There are many species of earths, some of which have names but others are unnamed.
"Solidified juices are dry and somewhat hard (subdurus) mineral bodies which when moistened with water do not soften but liquefy instead; or if they do soften, they differ greatly from the earths by their unctuousness (pingue) or by the material of which they consist.Although occasionally they have the hardness of stone, yet because they preserve the form and nature which they had when less hard, they can easily be distinguished from the stones.The juices are divided into 'meagre' and unctuous (macer et pinguis). The 'meagre' juices, since they originate from three different substances, are of three species. They are formed from a liquid mixed with earth, or with metal, or with a mineral compound. To the first species belong salt and Nitrum (soda); to the second, chrysocolla, verdigris, iron-rust, and azure; to the third, vitriol, alum, and an acrid juice which is unnamed. The first two of these latter are obtained from pyrites, which is numbered amongst the compound minerals. The third of these comes from Cadmia (in this case the cobalt-zinc-arsenic minerals; the acrid juice is probably zinc sulphate). To the unctuous juices belong these species: sulphur, bitumen, realgar and orpiment. Vitriol and alum, although they are somewhat unctuous yet do not burn, and they differ in their origin from the unctuous juices, for the latter are forced out from the earth by heat, whereas the former are produced when pyrites is softened by moisture.
[Pg 2] "Stone is a dry and hard mineral body which may either be softened by remaining for a long time in water and be reduced to powder by a fierce fire; or else it does not soften with water but the heat of a great fire liquefies it. To the first species belong those stones which have been solidified by heat, to the second those solidified (literally 'congealed') by cold. These two species of stones are constituted from their own material. However, writers on natural subjects who take into consideration the quantity and quality of stones and their value, divide them into four classes. The first of these has no name of its own but is called in common parlance 'stone': to this class belong loadstone, jasper (or bloodstone) and Aetites (geodes?) . The second class comprises hard stones, either pellucid or ornamental, with very beautiful and varied colours which sparkle marvellously; they are called gems. The third comprises stones which are only brilliant after they have been polished, and are usually called marble. The fourth are called rocks; they are found in quarries, from which they are hewn out for use in building, and they are cut into various shapes. None of the rocks show colour or take a polish. Few of the stones sparkle; fewer still are transparent. Marble is sometimes only distinguishable from opaque gems by its volume; rock is always distinguishable from stones properly so-called by its volume. Both the stones and the gems are usually to be found in veins and veinlets which traverse the rocks and marble. These four classes, as I have already stated, are divided into many species, which I will explain in their proper place.
"Metal is a mineral body, by nature either liquid or somewhat hard. The latter may be melted by the heat of the fire, but when it has cooled down again and lost all heat, it becomes hard again and resumes its proper form. In this respect it differs from the stone which melts in the fire, for although the latter regain its hardness, yet it loses its pristine form and properties. Traditionally there are six different kinds of metals, namely gold, silver, copper, iron, tin and lead. There are really others, for quicksilver is a metal, although the Alchemists disagree with us on this subject, and bismuth is also. The ancient Greek writers seem to have been ignorant of bismuth, wherefore Ammonius rightly states that there are many species of metals, animals, and plants which are unknown to us. Stibium when smelted in the crucible and refined has as much right to be regarded as a proper metal as is accorded to lead by writers. If when smelted, a certain portion be added to tin, a bookseller's alloy is produced from which the type is made that is used by those who print books on paper. Each metal has its own form which it preserves when separated from those metals which were mixed with it. Therefore neither electrum nor Stannum is of itself a real metal, but rather an alloy of two metals. Electrum is an alloy of gold and silver, Stannum of lead and silver (see note 33, p.473). And yet if silver be parted from the electrum, then gold remains and not electrum; if silver be taken away from Stannum, then lead remains and not Stannum. Whether brass, however, is found as a native metal or not, cannot be ascertained with any surety. We only know of the artificial brass, which consists of copper tinted with the colour of the mineral calamine. And yet if any should be dug up, it would be a proper metal. Black and white copper seem to be different from the red kind. Metal, therefore, is by nature either solid, as I have stated, or fluid, as in the unique case of quicksilver. But enough now concerning the simple kinds.
"I will now speak of the compounds which are composed of the simple minerals cemented together by nature, and under the word 'compound' I now discuss those mineral bodies which consist of two or three simple minerals. They are likewise mineral substances, but so thoroughly mixed and alloyed that even in the smallest part there is not wanting any substance that is contained in the whole. Only by the force of the fire is it possible to separate one of the simple mineral substances from another; either the third from the other two, or two from the third, if there were three in the same compound. These two, three or more bodies are so completely mixed into one new species that the pristine form of none of these is recognisable.
"The 'mixed' minerals, which are composed of those same simple minerals, differ from the 'compounds,' in that the simple minerals each preserves its own form so that they can be separated one from the other not only by fire but sometimes by water and sometimes by hand. As these two classes differ so greatly from one another I usually use two different words in order to distinguish one from the other. I am well aware that [Pg 3]Galen calls the metallic earth a compound which is really a mixture, but he who wishes to instruct others should bestow upon each separate thing a definite name."
For convenience of reference we may reduce the above to a diagram as follows:
| 1.Fluids and gases. | |||
| 2.Mineral bodies | A.Homogenous bodies | (a) Simple minerals | Earths |
| Solidified juices | |||
| Stones | |||
| Metals | |||
| (b) Compound minerals | Being heterogeneous mixtures of (a) | ||
| B.Mixtures. | Being homogenous mixtures of (a) | ||
[5] Experiendae—"a trial." That actual assaying in its technical sense is meant, is sufficiently evident from Book VII
[6] ...plumbum ...candidum ac cinereum vel nigrum. "Lead ... white, or ash-coloured, or black." Agricola himself coined the term plumbum cinereum for bismuth, no doubt following the Roman term for tin—plumbum candidum. The following passage from Bermannus (p. 439) is of interest, for it appears to be the first description of bismuth, although mention of it occurs in the Nützlich Bergbüchlin (see Appendix B)."Bermannus: I will show you another kind of mineral which is numbered amongst metals, but appears to me to have been unknown to the Ancients; we call it bisemutum. Naevius: Then in your opinion there are more kinds of metals than the seven commonly believed? Bermannus: More, I consider; for this which just now I said we called bisemutum, cannot correctly be called plumbum candidum (tin), nor nigrum (lead), but is different from both and is a third one. Plumbum candidum is whiter and plumbum nigrum is darker, as you see. Naevius: We see that this is of the colour of galena. Ancon: How then can bisemutum, as you call it, be distinguished from galena? Bermannus: Easily; when you take it in your hands it stains them with black, unless it is quite hard. The hard kind is not friable like galena, but can be cut. It is blacker than the kind of rudis silver which we say is almost the colour of lead, and thus is different from both. Indeed, it not rarely contains some silver. It generally indicates that there is silver beneath the place where it is found, and because of this our miners are accustomed to call it the 'roof of silver.' They are wont to roast this mineral, and from the better part they make metal; from the poorer part they make a pigment of a kind not to be despised."
[7] Nitrum. The Ancients comprised many salts under this head, but Agricola in the main uses it for soda, although sometimes he includes potash. He usually, however, refers to potash as lixivium or salt therefrom, and by other distinctive terms. For description of method of manufacture and discussion, see Book XII. , p. 558
[8] Atramentum sutorium—"Shoemaker's blacking." See p. 572 for description of method of manufacture and historical footnote. In the main Agricola means green vitriol, but he does describe three main varieties, green, blue, and white (De Natura Fossilium, p.219).The blue was of course copper sulphate, and it is fairly certain that the white was zinc vitriol.
[Pg 4][9] Lavandi—"Washing." By this term the author includes all the operations of sluicing, buddling, and wet concentration generally. There is no English equivalent of such wide application, and there is some difficulty in interpretation without going further than the author intends. Book VIII. is devoted to the subject.
[Pg 5][10] Operam et oleum perdit—"loss of labour and oil."
[11] In Veteribus et Novis Metallis, and Bermannus, Agricola states that the mines of Schemnitz were worked 800 years before that time (1530), or about 750 A.D., and, further, [Pg 6]that the lead mines of Goslar in the Hartz were worked by Otho the Great (936-973), and that the silver mines at Freiberg were discovered during the rule of Prince Otho (about 1170). To continue the argument to-day we could add about 360 years more of life to the mines of Goslar and Freiberg. See also Note 16, p.36, and note 19, p.37
[12] Xenophon. Essay on the Revenues of Athens, I., 5.
[Pg 7][13] Ovid, Metamorphoses, I., 137 to 143.
[14] Diogenes Laertius, II., 5. The lines are assigned, however, to Philemon, not Euripides. (Kock, Comicorum Atticorum Fragmenta II., 512).
[15] We have not considered it of sufficient interest to cite the references to all of the minor poets and those whose preserved works are but fragmentary. The translations from the Greek into Latin are not literal and suffer again by rendering into English; we have however considered it our duty to translate Agricola's view of the meaning.
[Pg 9][16] Diogenes Laertius, II.
[Pg 10][17] An inspection of the historical incidents mentioned here and further on, indicates that Agricola relied for such information on Diogenes Laertius, Plutarch, Livy, Valerius Maximus, Pliny, and often enough on Homer, Horace, and Virgil.
[18] Juvenal. Satires I., l. 112, and VI., l.298.
[Pg 11][19] Pliny, XXXIV., 39.
[20] Horace. Odes, I., 35, ll.17-20.
[Pg 15][21] Horace. Satires, II., 3, ll.99-102.
[Pg 16][22] Virgil. Æneid, III., l. 55, and I., l.349.
[Pg 17][23] Horace. Satires, I., l. 73; and Epistle, I., 10, l.47.
[Pg 18][25] Theognis. Maxims, II., l.210.
[Pg 19][26] Pindar. Olymp. II., 58-60.
[27] Antiphanes, 4.
[Pg 22][28] Jurati Venditores—"Sworn brokers."(?)
[Pg 23][29] There is no doubt that Thucydides had some connection with gold mines; he himself is the authority for the statement that he worked mines in Thrace. Agricola seems to have obtained his idea that Thucydides held an appointment from the Athenians in charge of mines in Thasos, from Marcellinus (Vita, Thucydides, 30), who also says that Thucydides obtained possession of mines in Thrace through his marriage with a Thracian woman, and that it was while residing on the mines at Scapte-Hyle that he wrote his history. Later scholars, however, find little warrant for these assertions. The gold mines of Thasos—an island off the mainland of Thrace—are frequently mentioned by the ancient authors. Herodotus, VI., 46-47, says:—"Their (the Thasians') revenue was derived partly from their possessions upon the mainland, partly from the mines which they owned. They were masters of the gold mines of Scapte-Hyle, the yearly produce of which amounted to eighty talents. Their mines in Thasos yielded less, but still were so prolific that besides being entirely free from land-tax they had a surplus of income derived from the two sources of their territory on the mainland and their mines, in common years two hundred and in best years three hundred talents. I myself have seen the mines in question. By far the most curious of them are those which the Phoenicians discovered at the time when they went with Thasos and colonized the island, which took its name from him. [Pg 24]These Phoenician workings are in Thasos itself, between Coenyra and a place called Aenyra over against Samothrace; a high mountain has been turned upside down in the search for ores." (Rawlinson's Trans.) . The occasion of this statement of Herodotus was the relations of the Thasians with Darius (521-486 B.C.). The date of the Phoenician colonization of Thasos is highly nebular—anywhere from 1200 to 900 B.C.
[30] Agricola, De Veteribus et Novis Metallis, Book I., p. 392, says:—"Conrad, whose nickname in former years was 'pauper,' suddenly became rich from the silver mines of Mount Jura, known as the Firstum."He was ennobled with the title of Graf Cuntz von Glück by the Emperor Maximilian (who was Emperor of the Holy Roman Empire, 1493-1519).Conrad was originally a working miner at Schneeberg where he was known as Armer Cuntz (poor Cuntz or Conrad) and grew wealthy from the mines of Fürst in Leberthal.This district is located in the Vosges Mountains on the borders of Lorraine and Upper Alsace.The story of Cuntz or Conrad von Glück is mentioned by Albinus (Meissnische Land und Berg Chronica, Dresden, 1589, p.116), Mathesius (Sarepta, Nuremberg, 1578, fol. XVI.), and by others.
[31] Vladislaus III. was King of Poland, 1434-44, and also became King of Hungary in 1440. Tursius seems to be a Latinized name and cannot be identified.
BOOK II.
ualities which the perfect miner should possess and the arguments which are urged for and against the arts of mining and metallurgy, as well as the people occupied in the industry, I have sufficiently discussed in the first Book. Now I have determined to give more ample information concerning the miners.
In the first place, it is indispensable that they should worship God with reverence, and that they understand the matters of which I am going to speak, and that they take good care that each individual performs his duties efficiently and diligently.It is decreed by Divine Providence that those who know what they ought to do and then take care to do it properly, for the most part meet with good fortune in all they undertake; on the other hand, misfortune overtakes the indolent and those who are careless in their work.No person indeed can, without great and sustained effort and labour, store in his mind the knowledge of every portion of the metallic arts which are involved in operating mines.If a man has the means of paying the necessary expense, he hires as many men as he needs, and sends them to the various works.Thus formerly Sosias, the Thracian, sent into the silver mines a thousand slaves whom he had hired from the Athenian Nicias, the son of Niceratus[1]But if a man cannot afford the expenditure he chooses of the various kinds of mining that work which he himself can most easily and efficiently do.Of these kinds, the two most important are the making prospect trenches and the washing of the sands of rivers, for out of these sands are often collected gold dust, or certain black stones from which tin is smelted, or even gems are sometimes found in them; the trenching occasionally lays bare at the grass-roots veins which are found rich in metals.If therefore by skill or by luck, such sands or veins shall fall into his hands, he will be able to establish his fortune without expenditure, and from poverty rise to wealth.If on the contrary, his hopes are not realized, then he can desist from washing or digging.
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 convallesSome 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.
The miner also should consider whether the roads from the neighbouring regions to the mines are good or bad, short or long.For since a region which is abundant in mining products very often yields no agricultural produce, and the necessaries of life for the workmen and others must all be imported, a bad and long road occasions much loss and trouble with porters and carriers, and this increases the cost of goods brought in, which, therefore, must be sold at high prices.This injures not so much the workmen as the masters; since on account of the high price of goods, the workmen are not content with the wages customary for their labour, nor can they be, and they ask higher pay from the owners.And if the owners refuse, the men will not work any longer in the mines but will go elsewhere.Although districts which yield metals and other mineral products are generally healthy, because, being often situated on high and lofty ground, they are fanned by every wind, yet sometimes they are unhealthy, as has been related in my other book, which is called "De Natura Eorum Quae Effluunt ex Terra."Therefore, a wise miner does not mine in such places, even if they are very productive, when he perceives unmistakable signs of pestilence.For if a man mines in an unhealthy region he may be alive one hour and dead the next.
Then, the miner should make careful and thorough investigation concerning the lord of the locality, whether he be a just and good man or a tyrant, for the latter oppresses men by force of his authority, and seizes their possessions for himself; but the former governs justly and lawfully and serves the common good.The miner should not start mining operations in a district which is oppressed by a tyrant, but should carefully consider if in the vicinity there is any other locality suitable for mining and make up his mind if the overlord there be friendly or inimical.If he be inimical the mine will be rendered unsafe through hostile attacks, in one of which all of the gold or silver, or other mineral products, laboriously collected with much cost, will be taken away from the owner and his workmen will be struck with terror; overcome by fear, they will hastily fly, to free themselves from the danger to which they are exposed.In this case, not only are the fortunes of the miner in the greatest peril but his very life is in jeopardy, for which reason he should not mine in such places.
Since several miners usually come to mine the veins in one locality, a settlement generally springs up, for the miner who began first cannot keep it exclusively for himself. The Bergmeister gives permits to some to mine the superior and some the inferior parts of the veins; to some he gives the cross veins, to others the inclined veins. If the man who first starts work finds the vein to be metal-bearing or yielding other mining products, it will not be to his advantage to cease work because the neighbourhood may be evil, but he will guard and defend his rights both by arms and by the law. When the Bergmeister[11] delimits the boundaries of each owner, it is the duty of a good miner to keep within his bounds, and of a prudent one to repel encroachments of his neighbours by the help of the law. But this is enough about the neighbourhood.
The miner should try to obtain a mine, to which access is not difficult, in a mountainous region, gently sloping, wooded, healthy, safe, and not far distant from a river or stream by means of which he may convey his mining products to be washed and smelted.This indeed, is the best position.As for the others, the nearer they approximate to this position the better they are; the further removed, the worse.
Now I will discuss that kind of minerals for which it is not necessary to dig, because the force of water carries them out of the veins.Of these there are two kinds, minerals—and their fragments[12]—and juices.When there are springs at the outcrop of the veins from which, as I have already said, the above-mentioned products are emitted, the miner should consider these first, to see whether there are metals or gems mixed with the sand, or whether the waters discharged are filled with juices.In case metals or gems have settled in the pool of the spring, not only should the sand from it be washed, but also that from the streams which flow from these springs, and even from the river itself into which they again discharge.If the springs discharge water containing some juice, this also should be collected; the further such a stream has flowed from the source, the more it receives plain water and the more diluted does it become, and so much the more deficient in strength.If the stream receives no water of another kind, or scarcely any, not only the rivers, but likewise the lakes which receive these waters, are of the same nature as the springs, and serve the same uses; of this kind is the lake which the Hebrews call the Dead Sea, and which is quite full of bituminous fluids[13]But I must return to the subject of the sands.
Springs may discharge their waters into a sea, a lake, a marsh, a river, or a stream; but the sand of the sea-shore is rarely washed, for although the water flowing down from the springs into the sea carries some metals or gems with it, yet these substances can scarcely ever be reclaimed, because they are dispersed through the immense body of waters and mixed up with other sand, and scattered far and wide in different directions, or they sink down into the depths of the sea.For the same reasons, the sands of lakes can very rarely be washed successfully, even though the streams rising from the mountains pour their whole volume of water into them.The particles of metals and gems from the springs are very rarely carried into the marshes, which are generally in level and open places.Therefore, the miner, in the first place, washes the sand of the spring, then of the stream which flows from it, then finally, that of the river into which the stream discharges.It is not worth the trouble to wash the sands of a large river which is on a level plain at a distance from the mountains.Where several springs carrying metals discharge their waters into one river, there is more hope of productive results from washing.The miner does not neglect even the sands of the streams in which excavated ores have been washed.
The waters of springs taste according to the juice they contain, and they differ greatly in this respect.There are six kinds of these tastes which the worker[14] especially observes and examines; there is the salty kind, which shows that salt may be obtained by evaporation; the nitrous, which indicates soda; the aluminous kind, which indicates alum; the vitrioline, which indicates vitriol; the sulphurous kind, which indicates sulphur; and as for the bituminous juice, out of which bitumen is melted down, the colour itself proclaims it to the worker who is evaporating it. The sea-water however, is similar to that of salt springs, and may be drawn into low-lying pits, and, evaporated by the heat of the sun, changes of itself into salt; similarly the water of some salt-lakes turns to salt when dried by the heat of summer. Therefore an industrious and diligent man observes and makes use of these things and thus contributes something to the common welfare.
The strength of the sea condenses the liquid bitumen which flows into it from hidden springs, into amber and jet, as I have described already in my books "De Subterraneorum Ortu et Causis"[15]. The sea, with certain directions of the wind, throws both these substances on shore, and for this reason the search for amber demands as much care as does that for coral.
Moreover, it is necessary that those who wash the sand or evaporate the water from the springs, should be careful to learn the nature of the locality, its roads, its salubrity, its overlord, and the neighbours, lest on account of difficulties in the conduct of their business they become either impoverished by exhaustive expenditure, or their goods and lives are imperilled.But enough about this.
The miner, after he has selected out of many places one particular spot adapted by Nature for mining, bestows much labour and attention on the veins. These have either been stripped bare of their covering by chance and thus lie exposed to our view, or lying deeply hidden and concealed they are found after close search; the latter is more usual, the former more rarely happens, and both of these occurrences must be explained. There is more than one force which can lay bare the veins unaided by the industry or toil of man; since either a torrent might strip off the surface, which happened in the case of the silver mines of Freiberg (concerning which I have written in Book I.of my work "De Veteribus et Novis Metallis")[16]; or they may be exposed through the force of the wind, when it uproots and destroys the trees which have grown over the veins; or by the breaking away of the rocks; or by long-continued heavy rains tearing away the mountain; or by an earthquake; or by a lightning flash; or by a snowslide; or by the violence of the winds: "Of such a nature are the rocks hurled down from the mountains by the force of the winds aided by the ravages of time."Or the plough may uncover the veins, for Justin relates in his history that nuggets of gold had been turned up in Galicia by the plough; or this may occur through a fire in the forest, as Diodorus Siculus tells us happened in the silver mines in Spain; and that saying of Posidonius is appropriate enough: "The earth violently moved by the fires consuming the forest sends forth new products, namely, gold and silver."[17] And indeed, Lucretius has explained the same thing more fully in the following lines: "Copper and gold and iron were discovered, and at the same time weighty silver and the substance of lead, when fire had burned up vast forests on the great hills, either by a discharge of heaven's lightning, or else because, when men were waging war with one another, forest fires had carried fire among the enemy in order to strike terror to them, or because, attracted by the goodness of the soil, they wished to clear rich fields and bring the country into pasture, or else to destroy wild beasts and enrich themselves with the game; for hunting with pitfalls and with fire came into use before the practice of enclosing the wood with toils and rousing the game with dogs. Whatever the fact is, from whatever cause the heat of flame had swallowed up the forests with a frightful crackling from their very roots, and had thoroughly baked the earth with fire, there would run from the boiling veins and collect into the hollows of the grounds a stream of silver and gold, as well as of copper and lead."[18] But yet the poet considers that the veins are not laid bare in the first instance so much by this kind of fire, but rather that all mining had its origin in this. And lastly, some other force may by chance disclose the veins, for a horse, if this tale can be believed, disclosed the lead veins at Goslar by a blow from his hoof[19]By such methods as these does fortune disclose the veins to us.
But by skill we can also investigate hidden and concealed veins, by observing in the first place the bubbling waters of springs, which cannot be very far distant from the veins because the source of the water is from them; secondly, by examining the fragments of the veins which the torrents break off from the earth, for after a long time some of these fragments are again buried in the ground.Fragments of this kind lying about on the ground, if they are rubbed smooth, are a long distance from the veins, because the torrent, which broke them from the vein, polished them while it rolled them a long distance; but if they are fixed in the ground, or if they are rough, they are nearer to the veins.The soil also should be considered, for this is often the cause of veins being buried more or less deeply under the earth; in this case the fragments protrude more or less widely apart, and miners are wont to call the veins discovered in this manner "fragmenta."[20]
Further, we search for the veins by observing the hoar-frosts, which whiten all herbage except that growing over the veins, because the veins emit a warm and dry exhalation which hinders the freezing of the moisture, for which reason such plants appear rather wet than whitened by the frost. This may be observed in all cold places before the grass has grown to its full size, as in the months of April and May; or when the late crop of hay, which is called the cordum, is cut with scythes in the month of September.Therefore in places where the grass has a dampness that is not congealed into frost, there is a vein beneath; also if the exhalation be excessively hot, the soil will produce only small and pale-coloured plants.Lastly, there are trees whose foliage in spring-time has a bluish or leaden tint, the upper branches more especially being tinged with black or with any other unnatural colour, the trunks cleft in two, and the branches black or discoloured.These phenomena are caused by the intensely hot and dry exhalations which do not spare even the roots, but scorching them, render the trees sickly; wherefore the wind will more frequently uproot trees of this kind than any others.Verily the veins do emit this exhalation.Therefore, in a place where there is a multitude of trees, if a long row of them at an unusual time lose their verdure and become black or discoloured, and frequently fall by the violence of the wind, beneath this spot there is a vein.Likewise along a course where a vein extends, there grows a certain herb or fungus which is absent from the adjacent space, or sometimes even from the neighbourhood of the veins.By these signs of Nature a vein can be discovered.
There are many great contentions between miners concerning the forked twig[21], for some say that it is of the greatest use in discovering veins, and others deny it. Some of those who manipulate and use the twig, first cut a fork from a hazel bush with a knife, for this bush they consider more efficacious than any other for revealing the veins, especially if the hazel bush grows above a vein.Others use a different kind of twig for each metal, when they are seeking to discover the veins, for they employ hazel twigs for veins of silver; ash twigs for copper; pitch pine for lead and especially tin, and rods made of iron and steel for gold.All alike grasp the forks of the twig with their hands, clenching their fists, it being necessary that the clenched fingers should be held toward the sky in order that the twig should be raised at that end where the two branches meet.Then they wander hither and thither at random through mountainous regions.It is said that the moment they place their feet on a vein the twig immediately turns and twists, and so by its action discloses the vein; when they move their feet again and go away from that spot the twig becomes once more immobile.
The truth is, they assert, the movement of the twig is caused by the power of the veins, and sometimes this is so great that the branches of trees growing near a vein are deflected toward it. On the other hand, those who say that the twig is of no use to good and serious men, also deny that the motion is due to the power of the veins, because the twigs will not move for everybody, but only for those who employ incantations and craft. Moreover, they deny the power of a vein to draw to itself the branches of trees, but they say that the warm and dry exhalations cause these contortions. Those who advocate the use of the twig make this reply to these objections: when one of the miners or some other person holds the twig in his hands, and it is not turned by the force of a vein, this is due to some peculiarity of the individual, which hinders and impedes the power of the vein, for since the power of the vein in turning and twisting the twig may be not unlike that of a magnet attracting and drawing iron toward itself, this hidden quality of a man weakens and breaks the force, just the same as garlic weakens and overcomes the strength of a magnet. For a magnet smeared with garlic juice cannot attract iron; nor does it attract the latter when rusty. Further, concerning the handling of the twig, they warn us that we should not press the fingers together too lightly, nor clench them too firmly, for if the twig is held lightly they say that it will fall before the force of the vein can turn it; if however, it is grasped too firmly the force of the hands resists the force of the veins and counteracts it. Therefore, they consider that five things are necessary to insure that the twig shall serve its purpose: of these the first is the size of the twig, for the force of the veins cannot turn too large a stick; secondly, there is the shape of the twig, which must be forked or the vein cannot turn it; thirdly, the power of the vein which has the nature to turn it; fourthly, the manipulation of the twig; fifthly, the absence of impeding peculiarities. These advocates of the twig sum up their conclusions as follows: if the rod does not move for everybody, it is due to unskilled manipulation or to the impeding peculiarities of the man which oppose and resist the force of the veins, as we said above, and those who search for veins by means of the twig need not necessarily make incantations, but it is sufficient that they handle it suitably and are devoid of impeding power; therefore, the twig may be of use to good and serious men in discovering veins.With regard to deflection of branches of trees they say nothing and adhere to their opinion.
A—Twig.B—Trench. [Pg 40] Since this matter remains in dispute and causes much dissention amongst miners, I consider it ought to be examined on its own merits. The wizards, who also make use of rings, mirrors and crystals, seek for veins with a divining rod shaped like a fork; but its shape makes no difference in the matter,—it might be straight or of some other form—for it is not the form of the twig that matters, but the wizard's incantations which it would not become me to repeat, neither do I wish to do so. The Ancients, by means of the divining rod, not only procured those things necessary for a livelihood or for luxury, but they were also able to alter the forms of things by it; as when the magicians changed the rods of the Egyptians into serpents, as the writings of the Hebrews relate[22]; and as in Homer, Minerva with a divining rod turned the aged Ulysses suddenly into a youth, and then restored him back again to old age; Circe also changed Ulysses' companions into beasts, but afterward gave them back again their human form[23]; moreover by his rod, which was called "Caduceus," Mercury gave sleep to watchmen and awoke slumberers[24]Therefore it seems that the divining rod passed to the mines from its impure origin with the magicians.Then when good men shrank with horror from the incantations and rejected them, the twig was retained by the unsophisticated common miners, and in searching for new veins some traces of these ancient usages remain.
But since truly the twigs of the miners do move, albeit they do not generally use incantations, some say this movement is caused by the power of the veins, others say that it depends on the manipulation, and still others think that the movement is due to both these causes.But, in truth, all those objects which are endowed with the power of attraction do not twist things in circles, but attract them directly to themselves; for instance, the magnet does not turn the iron, but draws it directly to itself, and amber rubbed until it is warm does not bend straws about, but simply draws them to itself.If the power of the veins were of a similar nature to that of the magnet and the amber, the twig would not so much twist as move once only, in a semi-circle, and be drawn directly to the vein, and unless the strength of the man who holds the twig were to resist and oppose the force of the vein, the twig would be brought to the ground; wherefore, since this is not the case, it must necessarily follow that the manipulation is the cause of the twig's twisting motion.It is a conspicuous fact that these cunning manipulators do not use a straight twig, but a forked one cut from a hazel bush, or from some other wood equally flexible, so that if it be held in the hands, as they are accustomed to hold it, it turns in a circle for any man wherever he stands.Nor is it strange that the twig does not turn when held by the inexperienced, because they either grasp the forks of the twig too tightly or hold them too loosely.Nevertheless, these things give rise to the faith among common miners that veins are discovered by the use of twigs, because whilst using these they do accidentally discover some; but it more often happens that they lose their labour, and although they might discover a vein, they become none the less exhausted in digging useless trenches than do the miners who prospect in an unfortunate locality.Therefore a miner, since we think he ought to be a good and serious man, should not make use of an enchanted twig, because if he is prudent and skilled in the natural signs, he understands that a forked stick is of no use to him, for as I have said before, there are the natural indications of the veins which he can see for himself without the help of twigs.So if Nature or chance should indicate a locality suitable for mining, the miner should dig his trenches there; if no vein appears he must dig numerous trenches until he discovers an outcrop of a vein.
A vena dilatata is rarely discovered by men's labour, but usually some force or other reveals it, or sometimes it is discovered by a shaft or a tunnel on a vena profunda[25]
The veins after they have been discovered, and likewise the shafts and tunnels, have names given them, either from their discoverers, as in the case at Annaberg of the vein called "Kölergang," because a charcoal burner discovered it; or from their owners, as the Geyer, in Joachimsthal, because part of the same belonged to Geyer; or from their products, as the "Pleygang" from lead, or the "Bissmutisch" at Schneeberg from bismuth[26]; or from some other circumstances, such as the rich alluvials from the torrent by which they were laid bare in the valley of Joachim.More often the first discoverers give the names either of persons, as those of German Kaiser, Apollo, Janus; or the name of an animal, as that of lion, bear, ram, or cow; or of things inanimate, as "silver chest" or "ox stalls"; or of something ridiculous, as "glutton's nightshade"; or finally, for the sake of a good omen, they call it after the Deity.In ancient times they followed the same custom and gave names to the veins, shafts and tunnels, as we read in Pliny: "It is wonderful that the shafts begun by Hannibal in Spain are still worked, their names being derived from their discoverers.One of these at the present day, called Baebelo, furnished Hannibal with three hundred pounds weight (of silver) per day."[27]
END OF BOOK II.
FOOTNOTES:
[Pg 25] [1] Xenophon. Essay on the Revenues of Athens, IV., 14.
"But we cannot but feel surprised that the State, when it sees many private individuals enriching themselves from its resources, does not imitate their proceedings; for we heard long ago, indeed, at least such of us as attended to these matters, that Nicias the son of Niceratus kept a thousand men employed in the silver mines, whom he let on hire to Sosias of Thrace on condition that he should give him for each an obolus a day, free of all charges; and this number he always supplied undiminished." (See also Note 6). An obolus a day each, would be about 23 oz. Troy of silver per day for the whole number. In modern value this would, of course, be but about 50s. per day, but in purchasing power the value would probably be 100 to 1 (see Note on p. 28).Nicias was estimated to have a fortune of 100 talents—about 83,700 Troy ounces of silver, and was one of the wealthiest of the Athenians.(Plutarch, Life of Nicias).
[Pg 26][2] Xenophon. Oeconomicus XII., 20."'I approve,' said Ischomachus, 'of the barbarian's answer to the King who found a good horse, and, wishing to fatten it as soon as possible, asked a man with a good reputation for horsemanship what would do it?'The man's reply was: 'Its master's eye.'"
[3] Praefectus Metallorum. In Saxony this official was styled the Berghauptmann. For further information see page 94 and note on page 78
[4] This statement is either based upon Apollodorus, whom Agricola does not mention among his authorities, or on Strabo, whom he does so include. The former in his work on Mythology makes such a statement, for which Strabo (XIV., 5, 28) takes him to task as follows: "With this vain intention they collected the stories related by the Scepsian [Pg 27](Demetrius), and taken from Callisthenes and other writers, who did not clear them from false notions respecting the Halizones; for example, that the wealth of Tantalus and of the Pelopidae was derived, it is said, from the mines about Phrygia and Sipylus; that of Cadmus from the mines of Thrace and Mount Pangaeum; that of Priam from the gold mines of Astyra, near Abydos (of which at present there are small remains, yet there is a large quantity of matter ejected, and the excavations are proofs of former workings); that of Midas from the mines about Mount Bermium; that of Gyges, Alyattes, and Croesus, from the mines in Lydia and the small deserted city between Atarneus and Pergamum, where are the sites of exhausted mines." (Hamilton's Trans. , Vol. III., p. 66).
In adopting this view, Agricola apparently applied a wonderful realism to some Greek mythology—for instance, in the legend of Midas, which tells of that king being rewarded by the god Dionysus, who granted his request that all he touched might turn to gold; but the inconvenience of the gift drove him to pray for relief, which he obtained by bathing in the Pactolus, the sands of which thereupon became highly auriferous. Priam was, of course, King of Troy, but Homer does not exhibit him as a mine-owner. Gyges, Alyattes, and Croesus were successively Kings of Lydia, from 687 to 546 B.C., and were no doubt possessed of great treasure in gold.Some few years ago we had occasion to inquire into extensive old workings locally reputed to be Croesus' mines, at a place some distance north of Smyrna, which would correspond very closely to the locality here mentioned.
[5] There can be no doubt that the Carthaginians worked the mines of Spain on an extensive scale for a very long period anterior to their conquest by the Romans, but whether the mines were worked by the Government or not we are unable to find any evidence.
[6] The silver mines of Mt. Laurion formed the economic mainstay of Athens for the three centuries during which the State had the ascendency in Greece, and there can be no doubt that the dominance of Athens and its position as a sea-power were directly due to the revenues from the mines. The first working of the mines is shrouded in mystery. The scarcity of silver in the time of Solon (638-598 B.C.) would not indicate any very considerable output at that time. According to Xenophon (Essay on Revenue of Athens, IV., 2), written about 355 B.C., "they were wrought in very ancient times." The first definite discussion of the mines in Greek record begins about 500 B.C., for about that time the royalties began to figure in the Athenian Budget (Aristotle, Constitution of Athens, 47). There can be no doubt that the mines reached great prosperity prior to the Persian invasion. In the year 484 B.C. the mines returned 100 Talents (about 83,700 oz. Troy) to the Treasury, and this, on the advice of Themistocles, was devoted to the construction of the fleet which conquered the Persians at Salamis (480 B.C.). The mines were much interfered with by the Spartan invasions from 431 to 425 B.C., and again by their occupation in 413 B.C.; and by 355 B.C., when Xenophon wrote the "Revenues," exploitation had fallen to a low ebb, for which he proposes the remedies noted by Agricola on p. 28. By the end of the 4th Century, B.C., the mines had again reached considerable prosperity, as is evidenced by Demosthenes' orations against Pantaenetus and against Phaenippus, and by Lycurgus' prosecution of Diphilos for robbing the supporting pillars. The domination of the Macedonians under Philip and Alexander at the end of the 4th and beginning of the 3rd Centuries B.C., however, so flooded Greece with money from the mines of Thrace, that this probably interfered with Laurion, at this time, in any event, began the decadence of these mines. Synchronous also was the decadence of Athens, and, but for fitful displays, the State was not able to maintain even its own independence, not to mention its position as a dominant State. Finally, Strabo, writing about 30 B.C. gives the epitaph of every mining district—reworking the dumps. He says (IX., 1, 23): "The silver mines in Attica were at first of importance, but [Pg 28]are now exhausted. The workmen, when the mines yielded a bad return to their labour, committed to the furnace the old refuse and scoria, and hence obtained very pure silver, for the former workmen had carried on the process in the furnace unskilfully."
Since 1860, the mines have been worked with some success by a French Company, thus carrying the mining history of this district over a period of twenty-seven centuries. The most excellent of many memoirs upon the mines at Laurion, not only for its critical, historical, and archæological value, but also because of its author's great insight into mining and metallurgy, is that of Edouard Ardaillon (Les Mines du Laurion dans l'Antiquité, Paris, 1897). We have relied considerably upon this careful study for the following notes, and would refer others to it for a short bibliography on the subject. We would mention in passing that Augustus Boeckh's "Silver Mines of Laurion," which is incorporated with his "Public Economy of Athens" (English Translation by Lewis, London, 1842) has been too much relied upon by English students. It is no doubt the product of one acquainted with written history, but without any special knowledge of the industry and it is based on no antiquarian research. The Mt. Laurion mining district is located near the southern end of the Attic Peninsula. The deposits are silver-lead, and they occur along the contact between approximately horizontal limestones and slates. There are two principal beds of each, thus forming three principal contacts. The most metalliferous of these contacts are those at the base of the slates, the lowest contact of the series being the richest. The ore-bodies were most irregular, varying greatly in size, from a thin seam between schist planes, to very large bodies containing as much as 200,000 cubic metres. The ores are argentiferous galena, accompanied by considerable amounts of blende and pyrites, all oxidized near the surface. The ores worked by the Ancients appear to have been fairly rich in lead, for the discards worked in recent years by the French Company, and the pillars left behind, ran 8% to 10% lead. The ratio of silver was from 40 to 90 ounces per ton of lead. The upper contacts were exposed by erosion and could be entered by tunnels, but the lowest and most prolific contact line was only to be reached by shafts. The shafts were ordinarily from four to six feet square, and were undoubtedly cut by hammer and chisel; they were as much as 380 feet deep. In some cases long inclines for travelling roads join the vertical shafts in depth. The drives, whether tunnels or from shafts, were not level, but followed every caprice of the sinuous contact. They were from two to two and a half feet wide, often driven in parallels with cross-cuts between, in order to exploit every corner of the contact. The stoping of ore-bodies discovered was undertaken quite systematically, the methods depending in the main on the shape of the ore-body. If the body was large, its dimensions were first determined by drives, crosscuts, rises, and [Pg 29]winzes, as the case might require. If the ore was mainly overhead it was overhand-stoped, and the stopes filled as work progressed, inclined winzes being occasionally driven from the stopes to the original entry drives. If the ore was mainly below, it was underhand-stoped, pillars being left if necessary—such pillars in some cases being thirty feet high. They also employed timber and artificial pillars. The mines were practically dry. There is little evidence of breaking by fire. The ore was hand-sorted underground and carried out by the slaves, and in some cases apparently the windlass was used. It was treated by grinding in mills and concentrating upon a sort of buddle. These concentrates—mostly galena—were smelted in low furnaces and the lead was subsequently cupelled. Further details of metallurgical methods will be found in Notes on p. 391 and p. 465, on metallurgical subjects.
The mines were worked by slaves. Even the overseers were at times apparently slaves, for we find (Xenophon, Memorabilia, II., 5) that Nicias paid a whole talent for a good overseer. A talent would be about 837 Troy ounces of silver. As wages of skilled labour were about two and one half pennyweights of silver per diem, and a family income of 100 ounces of silver per annum was affluence, the ratio of purchasing power of Attic coinage to modern would be about 100 to 1. Therefore this mine manager was worth in modern value roughly £8,000. The mines were the property of the State. The areas were defined by vertical boundaries, and were let on lease for definite periods for a fixed annual rent. More ample discussion of the law will be found on p. 83
[7] Xenophon. (Essay on The Revenues, IV., 30)."I think, however, that I am able to give some advice with regard to this difficulty also (the risk of opening new mines), and to show how new operations may be conducted with the greatest safety.There are ten tribes at Athens, and if to each of these the State should assign an equal number of slaves, and the tribes should all make new cuttings, sharing their fortunes in common, then if but one tribe should make any useful discovery it would point out something profitable to the whole; but if two, three, or four, or half the number should make some discovery, it is plain that the works would be more profitable in proportion, and that they should all fail is contrary to all experience in past times."(Watson's Trans.p.258).
[8] Agricola here refers to the proposal of Xenophon for the State to collect slaves and hire them to work the mines of Laurion. There is no evidence that this recommendation was ever carried out.
[9] Partes. Agricola, p. 89-91, describes in detail the organization and management of these share companies. See Note 8, p.90
[Pg 31][10] This island in the northern Ægean Sea has produced this "earth" from before Theophrastus' time (372-287 B.C.) down to the present day. According to Dana (System of Mineralogy 689), it is cimolite, a hydrous silicate of aluminium. The Ancients distinguished two kinds,—one sort used as a pigment, and the other for medicinal purposes. This latter was dug with great ceremony at a certain time of the year, moulded into cubes, and stamped with a goat,—the symbol of Diana. It thus became known as terra sigillata, and was an article of apothecary commerce down to the last century.It is described by Galen (XII., 12), Dioscorides (V., 63), and Pliny (XXXV., 14), as a remedy for ulcers and snake bites.
[Pg 33][11] Magister Metallorum. See Note 1, p.78, for the reasons of the adoption of the term Bergmeister and page 95 for details of his duties.
[12] Ramenta"Particles."The author uses this term indifferently for fragments, particles of mineral, concentrates, gold dust, black tin, etc., in all cases the result of either natural or artificial concentration.As in technical English we have no general term for both natural and artificial "concentrates," we have rendered it as the context seemed to demand.
[13] A certain amount of bitumen does float ashore in the Dead Sea; the origin of it is, however, uncertain. Strabo (XVI., 2, 42), Pliny (V., 15 and 16), and Josephus (IV., 8), all mention this fact. The lake for this reason is often referred to by the ancient writers by the name Asphaltites
[Pg 34][14] Excoctor,—literally, "Smelter" or "Metallurgist."
[15] This reference should be to the De Natura Fossilium (p. 230), although there is a short reference to the matter in De Ortu et Causis (p. 59). Agricola maintained that not only were jet and amber varieties of bitumen, but also coal and camphor and obsidian. As jet (gagates) is but a compact variety of coal, the ancient knowledge of this substance has more interest than would otherwise attach to the gem, especially as some materials described in this connection were no doubt coal.The Greeks often refer to a series of substances which burned, contained earth, and which no doubt comprised coal.Such substances are mentioned by Aristotle (De Mirabilibus33, 41, 125), Nicander (Theriaca. 37), and others, previous to the 2nd Century B.C., but the most ample description is that of Theophrastus (23-28): "Some of the more brittle stones there also are, which become as it were burning coals when put into a fire, and continue so a long time; of this kind are those about Bena, found in mines and washed down by the torrents, for they will take fire on burning coals being thrown on them, and will continue burning as long as anyone blows them; afterward they will deaden, and may after that be made to burn again. They are therefore of long continuance, but their smell is troublesome and disagreeable. That also which is called the spinus, is found in mines. This stone, cut in pieces and thrown together in a heap, exposed to the sun, burns; and that the more, if it be moistened or sprinkled with water (a pyritiferous shale?) . But the Lipara stone empties itself, as it were, in burning, and becomes like the pumice, changing at once both its colour and density; for before burning it is black, smooth, and compact. This stone is found in the Pumices, separately in different places, as it were, in [Pg 35]cells, nowhere continuous to the matter of them. It is said that in Melos the pumice is produced in this manner in some other stone, as this is on the contrary in it; but the stone which the pumice is found in is not at all like the Lipara stone which is found in it. Certain stones there are about Tetras, in Sicily, which is over against Lipara, which empty themselves in the same manner in the fire. And in the promontory called Erineas, there is a great quantity of stone like that found about Bena, which, when burnt, emits a bituminous smell, and leaves a matter resembling calcined earth. Those fossil substances that are called coals, and are broken for use, are earthy; they kindle, however, and burn like wood coals. These are found in Liguria, where there also is amber, and in Elis, on the way to Olympia over the mountains. These are used by smiths." (Based on Hill's Trans.) . Dioscorides and Pliny add nothing of value to this description.
Agricola (De Nat.Fos., p. 229-230) not only gives various localities of jet, but also records its relation to coal. As to the latter, he describes several occurrences, and describes the deposits as vena dilatata. Coal had come into considerable use all over Europe, particularly in England, long before Agricola's time; the oft-mentioned charter to mine sea-coal given to the Monks of Newbottle Abbey, near Preston, was dated 1210.
Amber was known to the Greeks by the name electrum, but whether the alloy of the same name took its name from the colour of amber or vice versa is uncertain. The gum is supposed to be referred to by Homer (Od. XV. 460), and Thales of Miletus (640-546 B.C.) is supposed to have first described its power of attraction.It is mentioned by many other Greek authors, Æschylus, Euripides, Aristotle, and others.The latter (De Mirabilibus, 81) records of the amber islands in the Adriatic, that the inhabitants tell the story that on these islands amber falls from poplar trees."This, they say, resembles gum and hardens like stone, the story of the poets being that after Phaeton was struck by lightning his sisters turned to poplar trees and shed tears of amber."Theophrastus (53) says: "Amber is also a stone; it is dug out of the earth in Liguria and has, like the before-mentioned (lodestone), a power of attraction."Pliny (XXXVII., 11) gives a long account of both the substance, literature, and mythology on the subject. His view of its origin was: "Certainly amber is obtained from the islands of the Northern Ocean, and is called by the Germans glaesum. For this reason the Romans, when Germanicus Cæsar commanded in those parts, called one of them Glaesaria, which was known to the barbarians as Austeravia. Amber originates from gum discharged by a kind of pine tree, like gum from cherry and resin from the ordinary pine. It is liquid at first, and issues abundantly and hardens in time by cold, or by the sea when the rising tides carry off the fragments from the shores of those islands. Certainly it is thrown on the coasts, and is so light that it appears to roll in the water. Our forefathers believed that it was the juice of a tree, for they called it succinum. And that it belongs to a kind of pine tree is proved by the odour of the pine tree which it gives when rubbed, and that it burns when ignited like a pitch pine torch." The term amber is of Arabic origin—from Ambar—and this term was adopted by the Greeks after the Christian era. Agricola uses the Latin term succinum and (De Nat.Fos., p.231-5) disputes the origin from tree gum, and contends for submarine bitumen springs.
[Pg 36][16] The statement in De Veteribus et Novis Metallis (p. 394) is as follows:—
"It came about by chance and accident that the silver mines were discovered at Freiberg in Meissen. By the river Sala, which is not unknown to Strabo, is Hala, which was once country, but is now a large town; the site, at any rate, even from Roman times was famous and renowned for its salt springs, for the possession of which the Hermunduri fought with the Chatti. When people carried the salt thence in wagons, as they now do straight through Meissen (Saxony) into Bohemia—which is lacking in that seasoning to-day no less than formerly—they saw galena in the wheel tracks, which had been uncovered by the torrents. This lead ore, since it was similar to that of Goslar, they put into their carts and carried to Goslar, for the same carriers were accustomed to carry lead from that city. And since much more silver was smelted from this galena than from that of Goslar, certain miners betook themselves to that part of Meissen in which is now situated Freiberg, a great and wealthy town; and we are told by consistent stories and general report that they grew rich out of the mines." Agricola places the discovery of the mines at Freiberg at about 1170. See Note 11, p.5
[17] Diodorus Siculus (V., 35)."These places being covered with woods, it is said that in ancient times these mountains were set on fire by shepherds, and continued burning for many days, and parched the earth, so that an abundance of silver ore was melted, and the metal flowed in streams of pure silver like a river."Aristotle, nearly three centuries before Diodorus, mentions this same story (De Mirabilibus, 87): "They say that in Ibernia the woods were set on fire by certain shepherds, and the earth thus heated, the country visibly flowed silver; and when some time later there were earthquakes, and the earth burst asunder at different places, a large amount of silver was collected."As the works of Posidonius are lost, it is probable that Agricola was quoting from Strabo (III., 2, 9), who says, in describing Spain: "Posidonius, in praising the amount and excellence of the metals, cannot refrain from his accustomed rhetoric, and becomes quite enthusiastic in exaggeration. He tells us we are not to disbelieve the fable that formerly the forests having been set on fire, the earth, which was loaded with silver and gold, melted and threw up these metals to the surface, for inasmuch as every mountain and wooded hill seemed to be heaped up with money by a lavish fortune." (Hamilton's Trans. I. , p. 220). Or he may have been quoting from the Deipnosophistae of Athenaeus (VI.), where Posidonius is quoted: "And the mountains ...when once the woods upon them had caught fire, spontaneously ran with liquid silver."
[Pg 37][18] Lucretius, De Rerum Natura V. 1241.
[19] Agricola's account of this event in De Veteribus et Novis Metallis is as follows (p. 393): "Now veins are not always first disclosed by the hand and labour of man, nor has art always demonstrated them; sometimes they have been disclosed rather by chance or by good fortune. I will explain briefly what has been written upon this matter in history, what miners tell us, and what has occurred in our times. Thus the mines at Goslar are said to have been found in the following way. A certain noble, whose name is not recorded, tied his horse, which was named Ramelus, to the branch of a tree which grew on the mountain. This horse, pawing the earth with its hoofs, which were iron shod, and thus turning it over, uncovered a hidden vein of lead, not unlike the winged Pegasus, who in the legend of the poets opened a spring when he beat the rock with his hoof. So just as that spring is named Hippocrene after that horse, so our ancestors named the mountain Rammelsberg. Whereas the perennial water spring of the poets would long ago have dried up, the vein even to-day exists, and supplies an abundant amount of excellent lead. That a horse can have opened a vein will seem credible to anyone who reflects in how many ways the signs of veins are shown by chance, all of which are explained in my work De Re Metallica. Therefore, here we will believe the story, both because it may happen that a horse may disclose a vein, and because the name of the mountain agrees with the story." Agricola places the discovery of Goslar in the Hartz at prior to 936. See Note 11, p.5
[20] FragmentaThe glossary gives "Geschube." This term is defined in the Bergwerks' Lexicon (Chemnitz, 1743, p. 250) as the pieces of stone, especially tin-stone, broken from the vein and washed out by the water—the croppings.
[Pg 38][21] So far as we are able to discover, this is the first published description of the divining rod as applied to minerals or water. Like Agricola, many authors have sought to find its origin among the Ancients. The magic rods of Moses and Homer, especially the rod with which the former struck the rock at Horeb, the rod described by Ctesias (died 398 B.C.) which attracted gold and silver, and the virgula divina of the Romans have all been called up for proof. It is true that the Romans are responsible for the name virgula divina, "divining rod," but this rod was used for taking auguries by casting bits of wood (Cicero, De Divinatione).Despite all this, while the ancient naturalists all give detailed directions for finding water, none mention anything akin to the divining rod of the Middle Ages.It is also worth noting that the Monk Theophilus in the 12th Century also gives a detailed description of how to find water, but makes no mention of the rod.There are two authorities sometimes cited as prior to Agricola, the first being Basil Valentine in his "Last Will and Testament" (XXIV-VIII.), and while there may be some reason (see Appendix) for accepting the authenticity of the "Triumphal Chariot of Antimony" by this author, as dating about 1500, there can be little doubt that the "Last Will and Testament" was spurious and dated about 50 years after Agricola.Paracelsus (De Natura Rerum IX.), says: "These (divinations) are vain and misleading, and among the first of them are divining rods, which have deceived many miners. If they once point rightly they deceive ten or twenty times." In his De Origine Morborum Invisibilium (Book I.) he adds that the "faith turns the rod." These works were no doubt written prior to De Re Metallica—Paracelsus died in 1541—but they were not published until some time afterward.Those interested in the strange persistence of this superstition down to the present day—and the files of the patent offices of the world are full of it—will find the subject exhaustively discussed in M.E.Chevreul's "De la Baguette Divinatoire," Paris, 1845; L.Figuier, "Histoire du Merveilleux dans les temps moderne II.", Paris, 1860; W.F.Barrett, Proceedings of the Society of Psychical Research, part 32, 1897, and 38, 1900; R.W.Raymond, American Inst.of Mining Engineers, 1883, p.411.Of the descriptions by those who believed in it there is none better than that of William Pryce (Mineralogia Cornubiensis, London, 1778, pp.113-123), who devotes much pains to a refutation of Agricola.When we consider that a century later than Agricola such an advanced mind as Robert Boyle (1626-1691), the founder of the Royal Society, was convinced of the genuineness of the divining rod, one is more impressed with the clarity of Agricola's vision.In fact, there were few indeed, down to the 19th Century, who did not believe implicitly in the effectiveness of this instrument, and while science has long since abandoned it, not a year passes but some new manifestation of its hold on the popular mind breaks out.
[Pg 40][22] Exodus VII., 10, 11, 12.
[23] Odyssey XVI., 172, and X., 238.
[Pg 41][24] Odyssey XXIV., 1, etc. The Caduceus of Hermes had also the power of turning things to gold, and it is interesting to note that in its oldest form, as the insignia of heralds and of ambassadors, it had two prongs.
[25] In a general way venae profundae were fissure veins and venae dilatatae were sheeted deposits. For description see Book III
[Pg 42][26] These mines are in the Erzgebirge. We have adopted the names given in the German translation.
[27] The quotation from Pliny (XXXIII., 31) as a whole reads as follows:—
"Silver is found in nearly all the provinces, but the finest of all in Spain; where it is found in the barren lands, and in the mountains. Wherever one vein of silver has been found, another is sure to be found not far away. This is the case of nearly all the metals, whence it appears that the Greeks derived metalla. It is wonderful that the shafts begun by Hannibal in Spain still remain, their names being derived from their makers. One of these at the present day called Baebelo, furnished Hannibal with three hundred pounds' weight (of silver) per day. This mountain is excavated for a distance of fifteen hundred paces; and for this distance there are waterbearers lighted by torches standing night and day baling out the water in turns, thus making quite a river." Hannibal dates 247-183 B.C. and was therefore dead 206 years when Pliny was born. According to a footnote in Bostock and Riley's translation of Pliny, these workings were supposed to be in the neighbourhood of Castulo, now Cazlona, near Linares. It was at Castulo that Hannibal married his rich wife Himilce; and in the hills north of Linares there are ancient silver mines still known as Los Pozos de Anibal.
BOOK III.
reviously I have given much information concerning the miners, also I have discussed the choice of localities for mining, for washing sands, and for evaporating waters; further, I described the method of searching for veins. With such matters I was occupied in the second book; now I come to the third book, which is about veins and stringers, and the seams in the rocks[1]. The term "vein" is sometimes used to indicate canales in the earth, but very often elsewhere by this name I have described that which may be put in vessels[2]; I now attach a second significance to these words, for by them I mean to designate any mineral substances which the earth keeps hidden within her own deep receptacles.
A, C—The mountain.B—Vena profunda [Pg 45] First I will speak of the veins, which, in depth, width, and length, differ very much one from another. Those of one variety descend from the surface of the earth to its lowest depths, which on account of this characteristic, I am accustomed to call "venae profundae."
A, D—The mountain.B, C—Vena dilatata [Pg 45] Another kind, unlike the venae profundae, neither ascend to the surface of the earth nor descend, but lying under the ground, expand over a large area; and on that account I call them "venae dilatatae."
A, B, C, D—The mountain.E, F, G, H, I, K—Vena cumulata [Pg 49] Another occupies a large extent of space in length and width; therefore I usually call it "vena cumulata," for it is nothing else than an accumulation of some certain kind of mineral, as I have described in the book entitled De Subterraneorum Ortu et Causis. It occasionally happens, though it is unusual and rare, that several accumulations of this kind are found in one place, each one or more fathoms in depth and four or five in width, and one is distant from another two, three, or more fathoms. When the excavation of these accumulations begins, they at first appear in the shape of a disc; then they open out wider; finally from each of such accumulations is usually formed a "vena cumulata."
A—Vena profundaB—Intervenium. C—Another vena profunda [Pg 50]
A & B—Vena dilatataeC—Intervenium. D & E—Other venae dilatatae [Pg 50] The space between two veins is called an intervenium; this interval between the veins, if it is between venae dilatatae is entirely hidden underground. If, however, it lies between venae profundae then the top is plainly in sight, and the remainder is hidden.
A—Wide vena profunda. B—Narrow vena profunda [Pg 53]
Venae profundae differ greatly one from another in width, for some of them are one fathom wide, some are two cubits, others one cubit; others again are a foot wide, and some only half a foot; all of which our miners call wide veins. Others on the contrary, are only a palm wide, others three digits, or even two; these they call narrow.But in other places where there are very wide veins, the widths of a cubit, or a foot, or half a foot, are said to be narrow; at Cremnitz, for instance, there is a certain vein which measures in one place fifteen fathoms in width, in another eighteen, and in another twenty; the truth of this statement is vouched for by the inhabitants.
A—Thin vena dilatata. B—Thick vena dilatata [Pg 54]
Venae dilatatae, in truth, differ also in thickness, for some are one fathom thick, others two, or even more; some are a cubit thick, some a foot, some only half a foot; and all these are usually called thick veins.Some on the other hand, are but a palm thick, some three digits, some two, some one; these are called thin veins.
A, B, C—Vein.D, E, F—Seams in the Rock (Commissurae Saxorum). [Pg 54]
Venae profundae vary in direction; for some run from east to west.
A, B, C—Vein.D, E, F—Seams in the Rocks [Pg 55] Others, on the other hand, run from west to east.
A, B, C—Vein.D, E, F—Seams in the Rocks [Pg 55] Others run from south to north.
A, B, C—Vein.D, E, F—Seams in the Rocks [Pg 56] Others, on the contrary, run from north to south.
The seams in the rocks indicate to us whether a vein runs from the east or from the west.For instance, if the rock seams incline toward the westward as they descend into the earth, the vein is said to run from east to west; if they incline toward the east, the vein is said to run from west to east; in a similar manner, we determine from the rock seams whether the veins run north or south.
[Pg 57] Now miners divide each quarter of the earth into six divisions; and by this method they apportion the earth into twenty-four directions, which they divide into two parts of twelve each. The instrument which indicates these directions is thus constructed. First a circle is made; then at equal intervals on one half portion of it right through to the other, twelve straight lines called by the Greeks διάμετροι, and in the Latin dimetientes, are drawn through a central point which the Greeks call κέντρον, so that the circle is thus divided into twenty-four divisions, all being of an equal size.Then, within the circle are inscribed three other circles, the outermost of which has cross-lines dividing it into twenty-four equal parts; the space between it and the next circle contains two sets of twelve numbers, inscribed on the lines called "diameters"; while within the innermost circle it is hollowed out to contain a magnetic needle[3]. The needle lies directly over that one of the twelve lines called "diameters" on which the number XII is inscribed at both ends.
When the needle which is governed by the magnet points directly from the north to the south, the number XII at its tail, which is forked, signifies the north, that number XII which is at its point indicates the south. The sign VI superior indicates the east, and VI inferior the west. Further, between each two cardinal points there are always five others which are not so important. The first two of these directions are called the prior directions; the last two are called the posterior, and the fifth direction lies immediately between the former and the latter; it is halved, and one half is attributed to one cardinal point and one half to the other. For example, between the northern number XII and the eastern number VI, are points numbered I, II, III, IV, V, of which I and II are northern directions lying toward the east, IV and V are eastern directions lying toward the north, and III is assigned, half to the north and half to the east.
One who wishes to know the direction of the veins underground, places over the vein the instrument just described; and the needle, as soon as it becomes quiet, will indicate the course of the vein.That is, if the vein proceeds from VI to VI, it either runs from east to west, or from west to east; but whether it be the former or the latter, is clearly shown by the seams in the rocks.If the vein proceeds along the line which is between V and VI toward the opposite direction, it runs from between the fifth and sixth divisions of east to the west, or from between the fifth and sixth divisions of west to the east; and again, whether it is the one or the other is clearly shown by the seams in the rocks.In a similar manner we determine the other directions.
[Pg 59] Now miners reckon as many points as the sailors do in reckoning up the number of the winds. Not only is this done to-day in this country, but it was also done by the Romans who in olden times gave the winds partly Latin names and partly names borrowed from the Greeks. Any miner who pleases may therefore call the directions of the veins by the names of the winds. There are four principal winds, as there are four cardinal points: the Subsolanus, which blows from the east; and its opposite the Favonius, which blows from the west; the latter is called by the Greeks Ζέφυρος, and the former ̓Απηλιώτης. There is the Auster, which blows from the south; and opposed to it is the Septentrio, from the north; the former the Greeks called Νότος, and the latter ̓Απαρκτίας. There are also subordinate winds, to the number of twenty, as there are directions, for between each two principal winds there are always five subordinate ones. Between the Subsolanus (east wind) and the Auster (south wind) there is the Ornithiae or the Bird wind, which has the first place next to the Subsolanus; then comes Caecias; then Eurus, which lies in the midway of these five; next comes Vulturnus; and lastly, Euronotus, nearest the Auster (south wind). The Greeks have given these names to all of these, with the exception of Vulturnus, but those who do not distinguish the winds in so precise a manner say this is the same as the Greeks called Εὖρος. Between the Auster (south wind) and the Favonius (west wind) is first Altanus, to the right of the Auster (south wind); then Libonotus; then Africus, which is the middle one of these five; after that comes Subvesperus; next Argestes, to the left of Favonius (west wind). All these, with the exception of Libonotus and Argestes, have Latin names; but Africus also is called by the Greeks Λίψ. In a similar manner, between Favonius (west wind) and Septentrio (north wind), first to the right of Favonius (west wind), is the Etesiae; then Circius; then Caurus, which is in the middle of these five; then Corus; and lastly Thrascias to the left of Septentrio (north wind). To all of these, except that of Caurus, the Greeks gave the names, and those who do not distinguish the winds by so exact a plan, assert that the wind which the Greeks called Κόρος and the Latins Caurus is one and the same. Again, between Septentrio (north wind) and the Subsolanus (east wind), the first to the right of Septentrio (north wind) is Gallicus; then Supernas; then Aquilo, which is the middle one of these five; next comes Boreas; and lastly Carbas, to the left of Subsolanus (east wind). Here again, those who do not consider the winds to be in so great a multitude, but say there are but twelve winds in all, or at the most fourteen, assert that the wind called by the Greeks Βορέας and the Latins Aquilo is one and the same. For our purpose it is not only useful to adopt this large number of winds, but even to double it, as the German sailors do. They always reckon that between each two there is one in the centre taken from both. By this method we also are able to signify the intermediate directions by means of the names of the winds. For instance, if a vein runs from VI east to VI west, it is said to proceed from Subsolanus (east wind) to Favonius (west wind); but one which proceeds from between V and VI of the east to between V and VI west is said to proceed out of the middle of Carbas and Subsolanus to between Argestes and Favonius; the remaining directions, and their intermediates are similarly designated.The miner, on account of the natural properties of a magnet, by which the needle points to the south, must fix the instrument already described so that east is to the left and west to the right.
A, B—Venae dilatataeC—Seams in the Rocks [Pg 60] In a similar way to venae profundae, the venae dilatatae vary in their lateral directions, and we are able to understand from the seams in the rocks in which direction they extend into the ground. For if these incline toward the west in depth, the vein is said to extend from east to west; if on the contrary, they incline toward the east, the vein is said to go from west to east. In the same way, from the rock seams we can determine veins running south and north, or the reverse, and likewise to the subordinate directions and their intermediates.
A—Straight vena profunda. B—Curved vena profunda [should be vena dilatata(?) ]. [Pg 61] Further, as regards the question of direction of a vena profunda, one runs straight from one quarter of the earth to that quarter which is opposite, while another one runs in a curve, in which case it may happen that a vein proceeding from the east does not turn to the quarter opposite, which is the west, but twists itself and turns to the south or the north.
A—Horizontal vena dilatata. B—Inclined vena dilatata. C—Curved vena dilatata [Pg 61] Similarly some venae dilatatae are horizontal, some are inclined, and some are curved.
[Pg 62] Also the veins which we call profundae differ in the manner in which they descend into the depths of the earth; for some are vertical (A), some are inclined and sloping (B), others crooked (C).
[Pg 62] Moreover, venae profundae (B) differ much among themselves regarding the kind of locality through which they pass, for some extend along the slopes of mountains or hills (A-C) and do not descend down the sides.
[Pg 63] Other Venae Profundae (D, E, F) from the very summit of the mountain or hill descend the slope (A) to the hollow or valley (B), and they again ascend the slope or the side of the mountain or hill opposite (C).
[Pg 63] Other Venae Profundae (C, D) descend the mountain or hill (A) and extend out into the plain (B).
A—Mountainous Plain.B—Vena profunda [Pg 64] Some veins run straight along on the plateaux, the hills, or plains.
A—Principal vein.B—Transverse vein.C—Vein cutting principal one obliquely. [Pg 64] In the next place, venae profundae differ not a little in the manner in which they intersect, since one may cross through a second transversely, or one may cross another one obliquely as if cutting it in two.
A—Principal vein.B—Vein which cuts A obliquely.C—Part carried away.D—That part which has been carried forward. [Pg 65] If a vein which cuts through another principal one obliquely be the harder of the two, it penetrates right through it, just as a wedge of beech or iron can be driven through soft wood by means of a tool. If it be softer, the principal vein either drags the soft one with it for a distance of three feet, or perhaps one, two, three, or several fathoms, or else throws it forward along the principal vein; but this latter happens very rarely. But that the vein which cuts the principal one is the same vein on both sides, is shown by its having the same character in its footwalls and hangingwalls.
A, B—Two veins descend inclined and dip toward each other.C—Junction.Likewise two veins.D—Indicates one descending vertically.E—Marks the other descending inclined, which dips toward D.F—Their junction. [Pg 66] Sometimes venae profundae join one with another, and from two or more outcropping veins[4], one is formed; or from two which do not outcrop one is made, if they are not far distant from each other, and the one dips into the other, or if each dips toward the other, and they thus join when they have descended in depth.In exactly the same way, out of three or more veins, one may be formed in depth.
[Pg 66] However, such a junction of veins sometimes disunites and in this way it happens that the vein which was the right-hand vein becomes the left; and again, the one which was on the left becomes the right.
A, B—Veins dividing.C—The same joining. [Pg 67] Furthermore, one vein may be split and divided into parts by some hard rock resembling a beak, or stringers in soft rock may sunder the vein and make two or more. These sometimes join together again and sometimes remain divided.
Whether a vein is separating from or uniting with another can be determined only from the seams in the rocks.For example, if a principal vein runs from the east to the west, the rock seams descend in depth likewise from the east toward the west, and the associated vein which joins with the principal vein, whether it runs from the south or the north, has its rock seams extending in the same way as its own, and they do not conform with the seams in the rock of the principal vein—which remain the same after the junction—unless the associated vein proceeds in the same direction as the principal vein.In that case we name the broader vein the principal one, and the narrower the associated vein.But if the principal vein splits, the rock seams which belong respectively to the parts, keep the same course when descending in depth as those of the principal vein.
A, C—Vena dilatata crossing a vena profundaB—Vena profundaD, E—Vena dilatata which junctions with a vena profundaF—Vena profundaG—Vena dilatataH, I—Its divided parts.K—Vena profunda which divides the vena dilatata [Pg 68] But enough of venae profundae, their junctions and divisions. Now we come to venae dilatatae. A vena dilatata may either cross a vena profunda, or join with it, or it may be cut by a vena profunda, and be divided into parts.
A—The "beginning" (origo).B—The "end" (finis).C—The "head" (caput).D—The "tail" (cauda). [Pg 69] Finally, a vena profunda has a "beginning" (origo), an "end" (finis), a "head" (caput), and a "tail" (cauda).That part whence it takes its rise is said to be its "beginning," that in which it terminates the "end."Its "head"[5] is that part which emerges into daylight; its "tail" that part which is hidden in the earth. But miners have no need to seek the "beginning" of veins, as formerly the kings of Egypt sought for the source of the Nile, but it is enough for them to discover some other part of the vein and to recognise its direction, for seldom can either the "beginning" or the "end" be found. The direction in which the head of the vein comes into the light, or the direction toward which the tail extends, is indicated by its footwall and hangingwall. The latter is said to hang, and the former to lie. The vein rests on the footwall, and the hangingwall overhangs it; thus, when we descend a shaft, the part to which we turn the face is the footwall and seat of the vein, that to which we turn the back is the hangingwall. Also in another way, the head accords with the footwall and the tail with the hangingwall, for if the footwall is toward the south, the vein extends its head into the light toward the south; and the hangingwall, because it is always opposite to the footwall, is then toward the north. Consequently the vein extends its tail toward the north if it is an inclined vena profunda. Similarly, we can determine with regard to east and west and the subordinate and their intermediate directions. A vena profunda which descends into the earth may be either vertical, inclined, or crooked; the footwall of an inclined vein is easily distinguished from the hangingwall, but it is not so with a vertical vein; and again, the footwall of a crooked vein is inverted and changed into the hangingwall, and contrariwise the hangingwall is twisted into the footwall, but very many of these crooked veins may be turned back to vertical or inclined ones.
A—The "beginning."B—The "end."C, D—The "sides." [Pg 69] A vena dilatata has only a "beginning" and an "end," and in the place of the "head" and "tail" it has two sides.