De Re Metallica Part 10

This is clearly shown by the following circ.u.mstance, that frequently the powder of rock or marble is found in a soft state and as if partly dissolved. Now, the water carries this mixture into the course of some underground _ca.n.a.lis_, or dragging it into narrow places, filters away.

And in each case the water flows away and a pure and uniform material is left from which 'earth' is made.... Particles of rock, however, are only by force of long time so softened by water as to become similar to particles of 'earth.' It is possible to see 'earth' being made in this way in underground _ca.n.a.les_ in the earth, when drifts or tunnels are driven into the mountains, or when shafts are sunk, for then the _ca.n.a.les_ are laid bare; also it can be seen above ground in ravines, as I have said, or otherwise disclosed. For in both cases it is clear to the eye that they are made out of the 'earth' or rocks, which are often of the same colour. And in just the same way they are made in the springs which the veins discharge. Since all those things which we see with our eyes and which are perceived with our senses, are more clearly understood than if they were learnt by means of reasoning, we deem it sufficient to explain by this argument our view of the origin of 'earth.' In the manner which I have described, 'earths' originate in veins and veinlets, seams in the rocks, springs, ravines, and other openings, therefore all 'earths' are made in this way. As to those that are found in underground _ca.n.a.les_ which do not appear to have been derived from the earth or rock adjoining, these have undoubtedly been carried by the water for a greater distance from their place of origin; which may be made clear to anyone who seeks their source."

On the origin of solidified juices he states (_De Ortu_, p. 43): "I will now speak of solidified juices (_succi concreti_). I give this name to those minerals which are without difficulty resolved into liquids (_humore_). Some stones and metals, even though they are themselves composed of juices, have been compressed so solidly by the cold that they can only be dissolved with difficulty or not at all.... For juices, as I said above, are either made when dry substances immersed in moisture are cooked by heat, or else they are made when water flows over 'earth,' or when the surrounding moisture corrodes metallic material; or else they are forced out of the ground by the power of heat alone.

Therefore, solidified juices originate from liquid juices, which either heat or cold have condensed. But that which heat has dried, fire reduces to dust, and moisture dissolves. Not only does warm or cold water dissolve certain solidified juices, but also humid air; and a juice which the cold has condensed is liquefied by fire and warm water. A salty juice is condensed into salt; a bitter one into soda; an astringent and sharp one into alum or into vitriol. Skilled workmen in a similar way to nature, evaporate water which contains juices of this kind until it is condensed; from salty ones they make salt, from aluminous ones alum, from one which contains vitriol they make vitriol.

These workmen imitate nature in condensing liquid juices with heat, but they cannot imitate nature in condensing them by cold. From an astringent juice not only is alum made and vitriol, but also _sory_, _chalcitis_, and _misy_, which appears to be the 'flower' of vitriol, just as _melanteria_ is of _sory_. (See note on p. 573 for these minerals.) When humour corrodes pyrites so that it is friable, an astringent juice of this kind is obtained."

ON THE ORIGIN OF STONES (_De Ortu_, p. 50), he states: "It is now necessary to review in a few words what I have said as to all of the material from which stones are made; there is first of all mud; next juice which is solidified by severe cold; then fragments of rock; afterward stone juice (_succus lapidescens_), which also turns to stone when it comes out into the air; and lastly, everything which has pores capable of receiving a stony juice." As to an "efficient force," he states (p. 54): "But it is now necessary that I should explain my own view, omitting the first and antecedent causes. Thus the immediate causes are heat and cold; next in some way a stony juice. For we know that stones which water has dissolved, are solidified when dried by heat; and on the contrary, we know that stones which melt by fire, such as quartz, solidify by cold. For solidification and the conditions which are opposite thereto, namely, dissolving and liquefying, spring from causes which are the opposite to each other. Heat, driving the water (_humorem_) out of a substance, makes it hard; and cold, by withdrawing the air, solidifies the same stone firmly. But if a stony juice, either alone or mixed with water, finds its way into the pores either of plants or animals ... it creates stones.... If stony juice is obtained in certain stony places and flows through the veins, for this reason certain springs, brooks, streams, and lakes, have the power of turning things to stone."

ON THE ORIGIN OF METALS, he says (_De Ortu_, p. 71): "Having now refuted the opinions of others, I must explain what it really is from which metals are produced. The best proof that there is water in their materials is the fact that they flow when melted, whereas they are again solidified by the cold of air or water. This, however, must be understood in the sense that there is more water in them and less 'earth'; for it is not simply water that is their substance but water mixed with 'earth.' And such a proportion of 'earth' is in the mixture as may obscure the transparency of the water, but not remove the brilliance which is frequently in unpolished things. Again, the purer the mixture, the more precious the metal which is made from it, and the greater its resistance to fire. But what proportion of 'earth' is in each liquid from which a metal is made no mortal can ever ascertain, or still less explain, but the one G.o.d has known it, Who has given certain sure and fixed laws to nature for mixing and blending things together.

It is a juice (_succus_) then, from which metals are formed; and this juice is created by various operations. Of these operations the first is a flow of water which softens the 'earth' or carries the 'earth' along with it, thus there is a mixture of 'earth' and water, then the power of heat works upon the mixtures so as to produce that kind of a juice. We have spoken of the substance of metals; we must now speak of their efficient cause.... (p. 75): We do not deny the statement of Albertus Magnus that the mixture of 'earth' and water is baked by subterranean heat to a certain denseness, but it is our opinion that the juice so obtained is afterward solidified by cold so as to become a metal.... We grant, indeed, that heat is the efficient cause of a good mixture of elements, and also cooks this same mixture into a juice, but until this juice is solidified by cold it is not a metal.... (p. 76): This view of Aristotle is the true one. For metals melt through the heat and somehow become softened; but those which have become softened through heat are again solidified by the influence of cold, and, on the contrary, those which become softened by moisture are solidified by heat."

ON THE ORIGIN OF COMPOUNDS, he states (_De Ortu_, p. 80): "There now remain for our consideration the compound minerals (_mistae_), that is to say, minerals which contain either solidified juice (_succus concretus_) and 'stone,' or else metal or metals and 'stone,' or else metal-coloured 'earth,' of which two or more have so grown together by the action of cold that one body has been created. By this sign they are distinguished from mixed minerals (_composita_), for the latter have not one body. For example, pyrites, galena, and ruby silver are reckoned in the category of compound minerals, whereas we say that metallic 'earths'

or stony 'earths' or 'earths' mingled with juices, are mixed minerals; or similarly, stones in which metal or solidified juices adhere, or which contain 'earth.' But of both these cla.s.ses I will treat more fully in my book _De Natura Fossilium_. I will now discuss their origin in a few words. A compound mineral is produced when either a juice from which some metal is obtained, or a _humour_ and some other juice from which stone is obtained, are solidified by cold, or when two or more juices of different metals mixed with the juice from which stone is made, are condensed by the same cold, or when a metallic juice is mixed with 'earth' whose whole ma.s.s is stained with its colour, and in this way they form one body. To the first cla.s.s belongs _galena_, composed of lead juice and of that material which forms the substance of opaque stone. Similarly, transparent ruby silver is made out of silver juice and the juice which forms the substance of transparent stone; when it is smelted into pure silver, since from it is separated the transparent juice, it is no longer transparent. Then too, there is pyrites, or _lapis fissilis_, from which sulphur is melted. To the second kind belongs that kind of pyrites which contains not only copper and stone, but sometimes copper, silver, and stone; sometimes copper, silver, gold, and stone; sometimes silver, lead, tin, copper and silver glance. That compound minerals consist of stone and metal is sufficiently proved by their hardness; that some are made of 'earth' and metal is proved from bra.s.s, which is composed of copper and calamine; and also proved from white bra.s.s, which is coloured by artificial white a.r.s.enic. Sometimes the heat bakes some of them to such an extent that they appear to have flowed out of blazing furnaces, which we may see in the case of _cadmia_ and pyrites. A metallic substance is produced out of 'earth' when a metallic juice impregnating the 'earth' solidifies with cold, the 'earth' not being changed. A stony substance is produced when viscous and non-viscous 'earth' are acc.u.mulated in one place and baked by heat; for then the viscous part turns into stone and the non-viscous is only dried up."

THE ORIGIN OF JUICES. The portion of Agricola's theory surrounding this subject is by no means easy to follow in detail, especially as it is difficult to adjust one's point of view to the Peripatetic elements, fire, water, earth, and air, instead of to those of the atomic theory which so dominates our every modern conception. That Agricola's 'juice'

was in most cases a solution is indicated by the statement (_De Ortu_, p. 48): "Nor is juice anything but water, which on the other hand has absorbed 'earth' or has corroded or touched metal and somehow become heated." That he realized the difference between mechanical suspension and solution is evident from (_De Ortu_, p. 50): "A stony juice differs from water which has abraded something from rock, either because it has more of that which deposits, or because heat, by cooking water of that kind, has thickened it, or because there is something in it which has powerful astringent properties." Much of the author's notion of juices has already been given in the quotations regarding various minerals, but his most general statement on the subject is as follows:--(_De Ortu_, p.

9): "Juices, however, are distinguished from water by their density (_cra.s.situdo_), and are generated in various ways--either when dry things are soaked with moisture and the mixture is heated, in which way by far the greatest part of juices arise, not only inside the earth, but outside it; or when water running over the earth is made rather dense, in which way, for the most part the juice becomes salty and bitter; or when the moisture stands upon metal, especially copper, and corrodes it, and in this way is produced the juice from which chrysocolla originates.

Similarly, when the moisture corrodes friable cupriferous pyrites an acrid juice is made from which is produced vitriol and sometimes alum; or, finally, juices are pressed out by the very force of the heat from the earth. If the force is great the juice flows like pitch from burning pine ... in this way we know a kind of bitumen is made in the earth. In the same way different kinds of moisture are generated in living bodies, so also the earth produces waters differing in quality, and in the same way juices."

CONCLUSION. If we strip his theory of the necessary influence of the state of knowledge of his time, and of his own deep cla.s.sical learning, we find two propositions original with Agricola, which still to-day are fundamentals:

(1) That ore channels were of origin subsequent to their containing rocks; (2) That ores were deposited from solutions circulating in these openings. A scientist's work must be judged by the advancement he gave to his science, and with this gauge one can say unhesitatingly that the theory which we have set out above represents a much greater step from what had gone before than that of almost any single observer since.

Moreover, apart from any tangible proposition laid down, the deduction of these views from actual observation instead of from fruitless speculation was a contribution to the very foundation of natural science. Agricola was wrong in attributing the creation of ore channels to erosion alone, and it was not until Von Oppel (_Anleitung zur Markscheidekunst_, Dresden, 1749 and other essays), two centuries after Agricola, that the positive proposition that ore channels were due to fissuring was brought forward. Von Oppel, however, in neglecting channels due to erosion (and in this term we include solution) was not altogether sound. Nor was it until late in the 18th century that the filling of ore channels by deposition from solutions was generally accepted. In the meantime, Agricola's successors in the study of ore deposits exhibited positive retrogression from the true fundamentals advocated by him. Gesner, Utman, Meier, Lohneys, Barba, Rossler, Becher, Stahl, Henckel, and Zimmerman, all fail to grasp the double essentials.

Other writers of this period often enough merely quote Agricola, some not even acknowledging the source, as, for instance, Pryce (_Mineralogia Cornubiensis_, London, 1778) and Williams (Natural History of the Mineral Kingdom, London, 1789). After Von Oppel, the two fundamental principles mentioned were generally accepted, but then arose the complicated and acrimonious discussion of the origin of solutions, and nothing in Agricola's view was so absurd as Werner's contention (_Neue Theorie von der Entstehung der Gange_, Freiberg, 1791) of the universal chemical deluge which penetrated fissures open at the surface. While it is not the purpose of these notes to pursue the history of these subjects subsequent to the author's time, it is due to him and to the current beliefs as to the history of the theory of ore deposits, to call the attention of students to the perverse representation of Agricola's views by Werner (op. cit.) upon which most writers have apparently relied. Why this author should be (as, for instance, by Posepny, Amer.

Inst. Mining Engineers, 1901) so generally considered the father of our modern theory, can only be explained by a general lack of knowledge of the work of previous writers on ore deposition. Not one of the propositions original with Werner still holds good, while his rejection of the origin of solutions within the earth itself halted the march of advance in thought on these subjects for half a century. It is our hope to discuss exhaustively at some future time the development of the history of this, one of the most far-reaching of geologic hypotheses.

[2] The Latin _vena_, "vein," is also used by the author for ore; hence this descriptive warning as to its intended double use.

[3] The endeavour to discover the origin of the compa.s.s with the Chinese, Arabs, or other Orientals having now generally ceased, together with the idea that the knowledge of the lodestone involved any acquaintance with the compa.s.s, it is permissible to take a rational view of the subject. The lodestone was well known even before Plato and Aristotle, and is described by Theophrastus (see Note 10, p. 115.) The first authentic and specific mention of the compa.s.s appears to be by Alexander Neckam (an Englishman who died in 1217), in his works _De Utensilibus_ and _De Naturis Rerum_. The first tangible description of the instrument was in a letter to Petrus Peregrinus de Maricourt, written in 1269, a translation of which was published by Sir Sylva.n.u.s Thompson (London, 1902). His circle was divided into four quadrants and these quarters divided into 90 degrees each. The first mention of a compa.s.s in connection with mines so far as we know is in the _Nutzlich Bergbuchlin_, a review of which will be found in Appendix B. This book, which dates from 1500, gives a compa.s.s much like the one described above by Agricola. It is divided in like manner into two halves of 12 divisions each. The four cardinal points being marked _Mitternacht_, _Morgen_, _Mittag_, and _Abend_. Thus the directions read were referred to as II. after midnight, etc. According to Joseph Carne (Trans. Roy.

Geol. Socy. of Cornwall, Vol. II, 1814), the Cornish miners formerly referred to North-South veins as 12 o'clock veins; South-East North-West veins as 9 o'clock veins, etc.

[4] _Crudariis._ Pliny (x.x.xIII., 31), says:--"_Argenti vena in summo reperta crudaria appellatur._" "Silver veins discovered at the surface are called _crudaria._" The German translator of Agricola uses the term _sylber gang_--silver vein, obviously misunderstanding the author's meaning.

[5] It might be considered that the term "outcrop" could be used for "head," but it will be noticed that a _vena dilatata_ would thus be stated to have no outcrop.

[6] It is possible that "veinlets" would be preferred by purists, but the word "stringer" has become fixed in the nomenclature of miners and we have adopted it. The old English term was "stringe," and appears in Edward Manlove's "Rhymed Chronicle," London, 1653; Pryce's, _Mineralogia Cornubiensis_, London, 1778, pp. 103 and 329; Mawe's "Mineralogy of Devonshire," London, 1802, p. 210, etc., etc.

[7] _Subdialis._ "In the open air." The Glossary gives the meaning as _Ein tag klufft oder tag gehenge_--a surface stringer.

[8] The following from Chapter IV of the _Nutzlich Bergbuchlin_ (see Appendix B) may indicate the source of the theory which Agricola here discards:--"As to those veins which are most profitable to work, it must be remarked that the most suitable location for the vein is on the slope of the mountain facing south, so its strike is from VII or VI east to VI or VII west. According to the above-mentioned directions, the outcrop of the whole vein should face north, its _gesteins ausgang_ toward the east, its hangingwall toward the south, and its footwall toward the north, for in such mountains and veins the influence of the planets is conveniently received to prepare the matter out of which the silver is to be made or formed.... The other strikes of veins from between east and south to the region between west and north are esteemed more or less valuable, according to whether they are nearer or further away from the above-mentioned strikes, but with the same hangingwall, footwall, and outcrops. But the veins having their strike from north to south, their hangingwall toward the west, their footwall and their outcrops toward the east, are better to work than veins which extend from south to north, whose hangingwalls are toward the east, and footwalls and outcrops toward the west. Although the latter veins sometimes yield solid and good silver ore, still it is not sure and certain, because the whole mineral force is completely scattered and dispersed through the outcrop, etc."

[9] The names in the Latin are given as _Donum Divinum_--"G.o.d's Gift,"

and _Coelestis Exercitus_--"Heavenly Host." The names given in the text are from the German Translation. The former of these mines was located in the valley of Joachim, where Agricola spent many years as the town physician at Joachimsthal. It is of further interest, as Agricola obtained an income from it as a shareholder. He gives the history of the mine (_De Veteribus et Novis Metallis_, Book I.), as follows:--"The mines at Abertham were discovered, partly by chance, partly by science.

In the eleventh year of Charles V. (1530), on the 18th of February, a poor miner, but one skilled in the art of mining, dwelt in the middle of the forest in a solitary hut, and there tended the cattle of his employer. While digging a little trench in which to store milk, he opened a vein. At once he washed some in a bowl and saw particles of the purest silver settled at the bottom. Overcome with joy he informed his employer, and went to the _Bergmeister_ and pet.i.tioned that official to give him a head mining lease, which in the language of our people he called _Gottsgaab_. Then he proceeded to dig the vein, and found more fragments of silver, and the miners were inspired with great hopes as to the richness of the vein. Although such hopes were not frustrated, still a whole year was spent before they received any profits from the mine; whereby many became discouraged and did not persevere in paying expenses, but sold their shares in the mine; and for this reason, when at last an abundance of silver was being drawn out, a great change had taken place in the ownership of the mine; nay, even the first finder of the vein was not in possession of any share in it, and had spent nearly all the money which he had obtained from the selling of his shares. Then this mine yielded such a quant.i.ty of pure silver as no other mine that has existed within our own or our fathers' memories, with the exception of the St. George at Schneeberg. We, as a shareholder, through the goodness of G.o.d, have enjoyed the proceeds of this 'G.o.d's Gift' since the very time when the mine began first to bestow such riches." Later on in the same book he gives the following further information with regard to these mines:--"Now if all the individual mines which have proved fruitful in our own times are weighed in the balance, the one at Annaberg, which is known as the _Himmelsch hoz_, surpa.s.ses all others.

For the value of the silver which has been dug out has been estimated at 420,000 Rhenish gulden. Next to this comes the lead mine in Joachimsthal, whose name is the _Sternen_, from which as much silver has been dug as would be equivalent to 350,000 Rhenish gulden; from the Gottsgaab at Abertham, explained before, the equivalent of 300,000. But far before all others within our fathers' memory stands the St. George of Schneeberg, whose silver has been estimated as being equal to two million Rhenish gulden." A Rhenish gulden was about 6.9 shillings, or, say, $1.66. However, the ratio value of silver to gold at this period was about 11.5 to one, or in other words an ounce of silver was worth about a gulden, so that, for purposes of rough calculation, one might say that the silver product mentioned in gulden is practically of the same number of ounces of silver. Moreover, it must be remembered that the purchasing power of money was vastly greater then.

[10] The following pa.s.sage occurs in the _Nutzlich Bergbuchlin_ (Chap.

V.), which is interesting on account of the great similarity to Agricola's quotation:--"The best position of the stream is when it has a cliff beside it on the north and level ground on the south, but its current should be from east to west--that is the most suitable. The next best after this is from west to east, with the same position of the rocks as already stated. The third in order is when the stream flows from north to south with rocks toward the east, but the worst flow of water for the preparation of gold is from south to north if a rock or hill rises toward the west." Calbus was probably the author of this booklet.

[11] Albertus Magnus.

BOOK IV.

The third book has explained the various and manifold varieties of veins and stringers. This fourth book will deal with mining areas and the method of delimiting them, and will then pa.s.s on to the officials who are connected with mining affairs[1].

Now the miner, if the vein he has uncovered is to his liking, first of all goes to the _Bergmeister_ to request to be granted a right to mine, this official's special function and office being to adjudicate in respect of the mines. And so to the first man who has discovered the vein the _Bergmeister_ awards the head meer, and to others the remaining meers, in the order in which each makes his application. The size of a meer is measured by fathoms, which for miners are reckoned at six feet each. The length, in fact, is that of a man's extended arms and hands measured across his chest; but different peoples a.s.sign to it different lengths, for among the Greeks, who called it an [Greek: orguia], it was six feet, among the Romans five feet. So this measure which is used by miners seems to have come down to the Germans in accordance with the Greek mode of reckoning. A miner's foot approaches very nearly to the length of a Greek foot, for it exceeds it by only three-quarters of a Greek digit, but like that of the Romans it is divided into twelve _unciae_[2].

[Ill.u.s.tration 79a (Square with lengths and area): Shape of a Square Meer.]

Now square fathoms are reckoned in units of one, two, three, or more "measures", and a "measure" is seven fathoms each way. Mining meers are for the most part either square or elongated; in square meers all the sides are of equal length, therefore the numbers of fathoms on the two sides multiplied together produce the total in square fathoms. Thus, if the shape of a "measure" is seven fathoms on every side, this number multiplied by itself makes forty-nine square fathoms.

[Ill.u.s.tration 79b (Rectangle with lengths and area): Shape of a Long Meer or Double Measure.]

The sides of a long meer are of equal length, and similarly its ends are equal; therefore, if the number of fathoms in one of the long sides be multiplied by the number of fathoms in one of the ends, the total produced by the multiplication is the total number of square fathoms in the long meer. For example, the double measure is fourteen fathoms long and seven broad, which two numbers multiplied together make ninety-eight square fathoms.

[Ill.u.s.tration 79c (Rectangle with lengths and area): Shape of a Head Meer.]

Since meers vary in shape according to the different varieties of veins it is necessary for me to go more into detail concerning them and their measurements. If the vein is a _vena profunda_, the head meer is composed of three double measures, therefore it is forty-two fathoms in length and seven in width, which numbers multiplied together give two hundred and ninety-four square fathoms, and by these limits the _Bergmeister_ bounds the owner's rights in a head-meer.

[Ill.u.s.tration 80a (Rectangle with lengths and area): Shape of a Meer.]

The area of every other meer consists of two double measures, on whichever side of the head meer it lies, or whatever its number in order may be, that is to say, whether next to the head meer, or second, third, or any later number. Therefore, it is twenty-eight fathoms long and seven wide, so multiplying the length by the width we get one hundred and ninety-six square fathoms, which is the extent of the meer, and by these boundaries the _Bergmeister_ defines the right of the owner or company over each mine.

Now we call that part of the vein which is first discovered and mined, the head-meer, because all the other meers run from it, just as the nerves from the head. The _Bergmeister_ begins his measurements from it, and the reason why he apportions a larger area to the head-meer than to the others, is that he may give a suitable reward to the one who first found the vein and may encourage others to search for veins. Since meers often reach to a torrent, or river, or stream, if the last meer cannot be completed it is called a fraction[3]. If it is the size of a double measure, the _Bergmeister_ grants the right of mining it to him who makes the first application, but if it is the size of a single measure or a little over, he divides it between the nearest meers on either side of it. It is the custom among miners that the first meer beyond a stream on that part of the vein on the opposite side is a new head-meer, and they call it the "opposite,"[4] while the other meers beyond are only ordinary meers. Formerly every head-meer was composed of three double measures and one single one, that is, it was forty-nine fathoms long and seven wide, and so if we multiply these two together we have three hundred and forty-three square fathoms, which total gives us the area of an ancient head-meer.

[Ill.u.s.tration 80b (Rectangle with lengths and area): Shape of an ancient Head-Meer.]

Every ancient meer was formed of a single measure, that is to say, it was seven fathoms in length and width, and was therefore square. In memory of which miners even now call the width of every meer which is located on a _vena profunda_ a "square"[5]. The following was formerly the usual method of delimiting a vein: as soon as the miner found metal, he gave information to the _Bergmeister_ and the t.i.the-gatherer, who either proceeded personally from the town to the mountains, or sent thither men of good repute, at least two in number, to inspect the metal-bearing vein. Thereupon, if they thought it of sufficient importance to survey, the _Bergmeister_ again having gone forth on an appointed day, thus questioned him who first found the vein, concerning the vein and the diggings: "Which is your vein?" "Which digging carried metal?" Then the discoverer, pointing his finger to his vein and diggings, indicated them, and next the _Bergmeister_ ordered him to approach the windla.s.s and place two fingers of his right hand upon his head, and swear this oath in a clear voice: "I swear by G.o.d and all the Saints, and I call them all to witness, that this is my vein; and moreover if it is not mine, may neither this my head nor these my hands henceforth perform their functions." Then the _Bergmeister_, having started from the centre of the windla.s.s, proceeded to measure the vein with a cord, and to give the measured portion to the discoverer,--in the first instance a half and then three full measures; afterward one to the King or Prince, another to his Consort, a third to the Master of the Horse, a fourth to the Cup-bearer, a fifth to the Groom of the Chamber, a sixth to himself. Then, starting from the other side of the windla.s.s, he proceeded to measure the vein in a similar manner. Thus the discoverer of the vein obtained the head-meer, that is, seven single measures; but the King or Ruler, his Consort, the leading dignitaries, and lastly, the _Bergmeister_, obtained two measures each, or two ancient meers. This is the reason there are to be found at Freiberg in Meissen so many shafts with so many intercommunications on a single vein--which are to a great extent destroyed by age. If, however, the _Bergmeister_ had already fixed the boundaries of the meers on one side of the shaft for the benefit of some other discoverer, then for those dignitaries I have just mentioned, as many meers as he was unable to award on that side he duplicated on the other. But if on both sides of the shaft he had already defined the boundaries of meers, he proceeded to measure out only that part of the vein which remained free, and thus it sometimes happened that some of those persons I have mentioned obtained no meer at all. To-day, though that old-established custom is observed, the method of allotting the vein and granting t.i.tle has been changed. As I have explained above, the head-meer consists of three double measures, and each other meer of two measures, and the _Bergmeister_ grants one each of the meers to him who makes the first application. The King or Prince, since all metal is taxed, is himself content with that, which is usually one-tenth.

Of the width of every meer, whether old or new, one-half lies on the footwall side of a _vena profunda_ and one half on the hangingwall side.

If the vein descends vertically into the earth, the boundaries similarly descend vertically; but if the vein inclines, the boundaries likewise will be inclined. The owner always holds the mining right for the width of the meer, however far the vein descends into the depth of the earth.[6] Further, the _Bergmeister_, on application being made to him, grants to one owner or company a right over not only the head meer, or another meer, but also the head meer and the next meer or two adjoining meers. So much for the shape of meers and their dimensions in the case of a _vena profunda_.

I now come to the case of _venae dilatatae_. The boundaries of the areas on such veins are not all measured by one method. For in some places the _Bergmeister_ gives them shapes similar to the shapes of the meers on _venae profundae_, in which case the head-meer is composed of three double measures, and the area of every other mine of two measures, as I have explained more fully above. In this case, however, he measures the meers with a cord, not only forward and backward from the ends of the head-meer, as he is wont to do in the case where the owner of a _vena profunda_ has a meer granted him, but also from the sides. In this way meers are marked out when a torrent or some other force of Nature has laid open a _vena dilatata_ in a valley, so that it appears either on the slope of a mountain or hill or on a plain. Elsewhere the _Bergmeister_ doubles the width of the head-meer and it is made fourteen fathoms wide, while the width of each of the other meers remains single, that is seven fathoms, but the length is not defined by boundaries. In some places the head-meer consists of three double measures, but has a width of fourteen fathoms and a length of twenty-one.

[Ill.u.s.tration 86a (Rectangle with lengths): Shape of a Head-Meer.]

[Ill.u.s.tration 86b (Square with lengths): Shape of every other Meer.]

In the same way, every other meer is composed of two measures, doubled in the same fashion, so that it is fourteen fathoms in width and of the same length.

Elsewhere every meer, whether a head-meer or other meer, comprises forty-two fathoms in width and as many in length.

In other places the _Bergmeister_ gives the owner or company all of some locality defined by rivers or little valleys as boundaries. But the boundaries of every such area of whatsoever shape it be, descend vertically into the earth; so the owner of that area has a right over that part of any _vena dilatata_ which lies beneath the first one, just as the owner of the meer on a _vena profunda_ has a right over so great a part of all other _venae profundae_ as lies within the boundaries of his meer; for just as wherever one _vena profunda_ is found, another is found not far away, so wherever one _vena dilatata_ is found, others are found beneath it.

Finally, the _Bergmeister_ divides _vena c.u.mulata_ areas in different ways, for in some localities the head-meer is composed of three measures, doubled in such a way that it is fourteen fathoms wide and twenty-one long; and every other meer consists of two measures doubled, and is square, that is, fourteen fathoms wide and as many long. In some places the head-meer is composed of three single measures, and its width is seven fathoms and its length twenty-one, which two numbers multiplied together make one hundred and forty-seven square fathoms.