PREVIOUSLY 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. 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; 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.
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."
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."
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."
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.
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.
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.
Venae Profundae vary in direction; for some run from east to west.
Others, on the other hand, run from west to east. Others run from south to north.
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.
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 diametroi, and in the Latin dimetientes, are drawn through a central point which the Greeks Call kentron, 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. 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.
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 Zephuros, and the former 'Apnliotes. There is the Auster, which blows from the south; and opposed to it is the Septentrio, from the north; the former the Greeks called Notos, and the latter 'Apharktias, 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 Euros. 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 AIL. 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 Koros 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 Boreas 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.
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.
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.
Similarly some venae dilatatae are horizontal, some are inclined, and some are curved.
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).
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.
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)
Other Venae Profundae (C, D) descend the mountain or hill (A) and extend out into the plain (B).
Some veins run straight along on the plateaux, the hills, or plains.
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 me may cross another one obliquely as if cutting it in two.
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 foot walls and hanging walls.
Sometimes venae profundae join one with another, and from two or more outcropping veins4, 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 reins, one may be formed in depth.
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.
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.
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.
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" 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 it.; 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 vena dilatata has only a " beginning " and an "end," and in the place of the " head " and " tail " it has two sides.
A vena cumulata has a "beginning," an "end," a "head," and a " tail," just as a vena Profunda. Moreover, a vena cumulata, and likewise a vena dilatata, are often cut through by a transverse vena profunda.
Stringers (fibrae), which are little veins, are classified into fibrae transversae, fibrae obliquae which cut the vein obliquely, fibrae sociae, fibrae dilatatae, and fibrae incumbentes. The fibra transversa crosses the vein; the fibra obliqua crosses the vein obliquely; the fibra socia joins with the vein itself; the fibra dilatata, like the vena dilatata, penetrates through it; but the fibra dilatata, as well as the fibra Profunda, is usually found associated with a vein.
The fibra incumbens does not descend as deeply into the earth as the other stringers, but lies on the vein, as it were, from the surface to the hangingwall or footwall, from which it is named Subdialis.
In truth, as to direction, junctions, and divisions, the stringers are not different from the veins.
Lastly, the seams, which are the very finest stringers (fibrae), divide the rock, and occur sometimes frequently, sometimes rarely. From whatever direction the vein comes, its seams always turn their heads toward the light in the same direction. But, while the seams usually run from one point of the compass to another immediately opposite it, as for instance, from east to west, if hard stringers divert them, it may happen that these very seams, which before were running from east to west, then contrariwise proceed from west to east, and the direction of the rocks is thus inverted. In such a case, the direction of the veins is judged, not by the direction of the seams which occur rarely, but by those which constantly recur.
Both veins or stringers may be solid or drusy, or barren of minerals; or pervious to water. Solid veins contain no water and very little air. The drusy veins rarely contain water; they often contain air. Those which are barren of minerals often carry water. Solid veins and stringers consist sometimes of hard materials, sometimes of soft, and sometimes of a kind of medium between the two.
But to return to veins. A great number of miners considers that the best veins in depth are those which run from the VI or VII direction of the east to the VI or VII direction of the west, through a mountain slope which inclines to the north; and whose hangingwalls are in the south, and whose footwalls are in the north, and which have their heads rising to the north, as explained before, always like the footwall, and finally, whose rock seams turn their heads to the east. And the veins which are the next best are those which, on the contrary, extend from the VI or VII direction of the west to the VI or VII direction of the east, through the slope of a mountain which similarly inclines to the north, whose hangingwalls are also in the south, whose footwalls are in the north, and whose heads rise toward the north; and lastly, whose rock seams raise their heads toward the west. In the third place, they recommend those veins which extend from XII north to XII south, through the slope of a mountain which faces east; whose hangingwalls are in the west, whose footwalls are in the east; whose heads rise toward the east; and whose rock seams raise their heads toward the north. Therefore they devote all their energies to those veins, and give very little or nothing to those whose heads, or the heads of whose rock seams rise toward the south or west. For although they say these veins sometimes show bright specks of pure metal adhering to the stones, or they come upon lumps of metal, yet these are so few and far between that despite them it is not worth the trouble to excavate such veins; and miners who persevere in digging in the hope of coming upon a quantity of metal, always lose their time and trouble. And they say that from veins of this kind, since the sun's rays draw out the metallic material, very little metal is gained. But in this matter the actual experience of the miners who thus judge of the veins does not always agree with their opinions, nor is their reasoning sound; since indeed the veins which run from east to west through the slope of a mountain which inclines to the south, whose heads rise likewise to the south, are not less charged with metals, than those to which miners are wont to accord the first place in productiveness; as in recent years has been proved by the St. Lorentz vein at Abertham, which our countrymen call Gottsgaab, for they have dug out of it a large quantity of pure silver; and lately a vein in Annaberg, called by the name of Himmelsch hoz, has made it plain by the production of much silver that veins which extend from the north to the south, with their heads rising toward the west, are no less rich in metals than those whose heads rise toward the east.
It may be denied that the heat of the sun draws the metallic material out of these veins; for though it draws up vapours from the surface of the ground, the rays of the sun do not penetrate right down to the depths; because the air of a tunnel which is covered and enveloped by solid earth to the depth of only two fathoms is cold in summer, for the intermediate earth holds in check the force of the sun. Having observed this fact, the inhabitants and dwellers of very hot regions lie down by day in caves which protect them from the excessive ardour of the sun. Therefore it is unlikely that the sun draws out from within the earth the metallic bodies. Indeed, it cannot even dry the moisture of many places abounding in veins, because they are protected and shaded by the trees. Furthermore, certain miners, out of all the different kinds of metallic veins, choose those which I have described, and others, on the contrary, reject copper mines which are of this sort, so that there seems to be no reason in this. For what can be the reason if the sun draws no copper from copper veins, that it draws silver from silver veins, and gold from gold veins?
Moreover, some miners, of whose number was Calbus distinguish between the gold-bearing rivers and streams. A river, they say, or a stream, is most productive of fine and coarse grains of gold when it comes from the east and flows to the west, and when it washes against the foot of mountains which are situated in the north, and when it has a level plain toward the south or west. In the second place, they esteem a river or a stream which flows in the opposite course from the west toward the east, and which has the mountains to the north and the level plain to the south. In the third place, they esteem the river or the stream which flows from the north to the south and washes the base of the mountains which are situated in the east. But they say that the river or stream is least productive of gold which flows in a contrary direction from the south to the north, and washes the base of mountains which are situated in the west. Lastly, of the streams or rivers which flow from the rising sun toward the setting sun, or which flow from the northern parts to the southern parts, they favour those which approach the nearest to the lauded ones, and say they are more productive of gold, and the further they depart from them the less productive they are. Such are the opinions held about rivers and streams. Now, since gold is not generated in the rivers and streams, as we have maintained against Albertus in the book entitled " De Subterraneorum Ortu et Causis," Book V, but is torn away from the veins and stringers and settled in the sands of torrents and water-courses, in whatever direction the rivers or streams flow, therefore it is reasonable to expect to find gold therein; which is not opposed by experience. Nevertheless, we do not deny that gold is generated in veins and stringers which lie under the beds of rivers or streams, as in other places.
END OF BOOK III.