FOOTNOTES:

[Pg 101][1] It has been suggested that we should adopt throughout this volume the mechanical and mining terms used in English mines at Agricola's time. We believe, however, that but a little inquiry would illustrate the undesirability of this course as a whole. Where there is choice in modern miner's nomenclature between an old and a modern term, we have leaned toward age, if it be a term generally understood. But except where the subject described has itself become obsolete, we have revived no obsolete terms. In substantiation of this view, we append a few examples of terms which served the English miner well for centuries, some of which are still extant in some local communities, yet we believe they would carry as little meaning to the average reader as would the reproduction of the Latin terms coined by Agricola.

Rake		= A perpendicular vein.
Woughs		= Walls of the vein.
Shakes		= Cracks in the walls.
Flookan		= Gouge.
Bryle		= Outcrop.
Hade		= Incline or underlay of the vein.
Dawling		= Impoverishment of the vein.
Rither		= A "horse" in a vein.
Twitches		= "Pinching" of a vein.
Slough		= Drainage tunnel.
Sole		= Lowest drift.
Stool		= Face of a drift or stope.
Winds	}	= Winze.
Turn
Dippas
Grove		= Shaft.
Dutins		= Set of timber.
Stemple		= Post or stull.
Laths		= Lagging.

As examples of the author's coinage and adaptations of terms in this book we may cite:—

Fossa latens	= Drift.
Fossa latens transversa	= Crosscut.
Tectum	= Hangingwall.
Fundamentum	= Footwall.
Tigna per intervalla posita	= Wall plate.
Arbores dissectae	= Lagging.
Formae	= Hitches.

We have adopted the term "tunnel" for openings by way of outlet to the mine. The word in this narrow sense is as old as "adit," a term less expressive and not so generally used in the English-speaking mining world. We have for the same reason adopted the word "drift" instead of the term "level" so generally used in America, because that term always leads to confusion in discussion of mine surveys. We may mention, however, that the term "level" is a heritage from the Derbyshire mines, and is of an equally respectable age as "drift."

[2] See note on p. [46]-[47]. The canales, as here used, were the openings in the earth, in which minerals were deposited.

[Pg 102][3] This statement, as will appear by the description later on, refers to the depth of winzes or to the distance between drifts, that is "the lift." We have not, however, been justified in using the term "winze," because some of these were openings to the surface. As showing the considerable depth of shafts in Agricola's time, we may quote the following from Bermannus (p. 442): "The depths of our shafts forced us to invent hauling machines suitable for them. There are some of them larger and more ingenious than this one, for use in deep shafts, as, for instance, those in my native town of Geyer, but more especially at Schneeberg, where the shaft of the mine from which so much treasure was taken in our memory has reached the depth of about 200 fathoms (feet?), wherefore the necessity of this kind of machinery. Naevius: What an enormous depth! Have you reached the Inferno? Bermannus: Oh, at Kuttenberg there are shafts more than 500 fathoms (feet?) deep. Naevius: And not yet reached the Kingdom of Pluto?" It is impossible to accept these as fathoms, as this would in the last case represent 3,000 feet vertically. The expression used, however, for fathoms is passus, presumably the Roman measure equal to 58.1 inches.

[Pg 107][4] Cavernos. The Glossary gives drusen, our word drusy having had this origin.

[5] Purum,—"pure." Interpretatio gives the German as gedigen,—"native."

[Pg 108][6] Rudis,—"Crude." By this expression the author really means ores very rich in any designated metal. In many cases it serves to indicate the minerals of a given metal, as distinguished from the metal itself. Our system of mineralogy obviously does not afford an acceptable equivalent. Agricola (De Nat. Foss., p. 360) says: "I find it necessary to call each genus (of the metallic minerals) by the name of its own metal, and to this I add a word which differentiates it from the pure (puro) metal, whether the latter has been mined or smelted; so I speak of rudis gold, silver, quicksilver, copper, tin, bismuth, lead, or iron. This is not because I am unaware that Varro called silver rudis which had not yet been refined and stamped, but because a word which will distinguish the one from the other is not to be found."

[7] The reasons for retaining the Latin weights are given in the [Appendix] on Weights and Measures. A centumpondium weighs 70.6 lbs. avoirdupois, an uncia 412.2 Troy grains, therefore, this value is equal to 72 ounces 18 pennyweights per short ton.

[8] Agricola mentions many minerals in De Re Metallica, but without such description as would make possible a hazard at their identity. From his De Natura Fossilium, however, and from other mineralogies of the 16th Century, some can be fully identified and others surmised. While we consider it desirable to set out the probable composition of these minerals, on account of the space required, the reasons upon which our opinion has been based cannot be given in detail, as that would require extensive quotations. In a general way, we have throughout the text studiously evaded the use of modern mineralogical terms—unless the term used to-day is of Agricola's age—and have adopted either old English terms of pre-chemistry times or more loose terms used by common miners. Obviously modern mineralogic terms imply a precision of knowledge not existing at that period. It must not be assumed that the following is by any means a complete list of the minerals described by Agricola, but they include most of those referred to in this chapter. His system of mineralogy we have set out in [note 4, p. 1], and it requires no further comment here. The grouping given below is simply for convenience and does not follow Agricola's method. Where possible, we tabulate in columns the Latin term used in De Re Metallica; the German equivalent given by the Author in either the Interpretatio or the Glossary; our view of the probable modern equivalent based on investigation of his other works and other ancient mineralogies, and lastly the terms we have adopted in the text. The German spelling is that given in the original. As an indication of Agricola's position as a mineralogist, we mark with an asterisk the minerals which were first specifically described by him. We also give some notes on matters of importance bearing on the nomenclature used in De Re Metallica. Historical notes on the chief metals will be found elsewhere, generally with the discussion of smelting methods. We should not omit to express our indebtedness to Dana's great "System of Mineralogy," in the matter of correlation of many old and modern minerals.

Gold Minerals. Agricola apparently believed that there were various gold minerals, green, yellow, purple, black, etc. There is nothing, however, in his works that permits of any attempt to identify them, and his classification seems to rest on gangue colours.

Silver Minerals.

Argentum purum in venis reperitur	Gedigen silber		*Native silver
Argentum rude	Gedigen silber ertz		Rudis silver, or pure silver minerals
Argentum rude plumbei coloris	Glas ertz	Argentite (Ag₂S)	*Silver glance
Argentum rude rubrum	Rot gold ertz	Pyrargyrite (Ag₃SbS₃)	*Red silver
Argentum rude rubrum translucidum	Durchsichtig rod gulden ertz	Proustite (Ag₃AsS₃)	*Ruby silver
Argentum rude album	Weis rod gulden ertz: Dan es ist frisch wie offtmals rod gulden ertz pfleget zusein		White silver
[Pg 109]Argentum rude jecoris colore	Gedigen leberfarbig ertz	Part Bromyrite (Ag Br)	Liver-coloured silver
Argentum rude luteum	Gedigen geelertz		Yellow silver
Argentum rude cineraceum	Gedigen graw ertz	Part Cerargurite (Ag Cl) (Horn Silver) Part Stephanite (Ag₅SbS₄)	*Grey silver
Argentum rude nigrum	Gedigen schwartz ertz		*Black silver
Argentum rude purpureum	Gedigen braun ertz		*Purple silver

The last six may be in part also alteration products from all silver minerals.

The reasons for indefiniteness in determination usually lie in the failure of ancient authors to give sufficient or characteristic descriptions. In many cases Agricola is sufficiently definite as to assure certainty, as the following description of what we consider to be silver glance, from De Natura Fossilium (p. 360), will indicate: "Lead-coloured rudis silver is called by the Germans from the word glass (glasertz), not from lead. Indeed, it has the colour of the latter or of galena (plumbago), but not of glass, nor is it transparent like glass, which one might indeed expect had the name been correctly derived. This mineral is occasionally so like galena in colour, although it is darker, that one who is not experienced in minerals is unable to distinguish between the two at sight, but in substance they differ greatly from one another. Nature has made this kind of silver out of a little earth and much silver. Whereas galena consists of stone and lead containing some silver. But the distinction between them can be easily determined, for galena may be ground to powder in a mortar with a pestle, but this treatment flattens out this kind of rudis silver. Also galena, when struck by a mallet or bitten or hacked with a knife, splits and breaks to pieces; whereas this silver is malleable under the hammer, may be dented by the teeth, and cut with a knife."

Copper Minerals.

Aes purum fossile	Gedigen kupfer	Native copper	Native copper
Aes rude plumbei coloris	Kupferglas ertz	Chalcocite (Cu₂S)	*Copper glance
Chalcitis	Rodt atrament	A decomposed copper or iron sulphide	Chalcitis (see notes on p. [573])
Pyrites aurei colore	Geelkis oder kupferkis	Part chalcopyrite (Cu Fe S) part bornite (Cu₃FeS₃)	Copper pyrites
Pyrites aerosus	Geelkis oder kupferkis	Part chalcopyrite (Cu Fe S) part bornite (Cu₃FeS₃)	Copper pyrites
Caeruleum	Berglasur	Azurite	Azure
Chrysocolla	Berggrün und	Part chrysocolla	Chrysocolla (see [note 7, p. 560])
Chrysocolla	schifergrün	Part Malachite	Chrysocolla (see [note 7, p. 560])
Molochites	Molochit	Malachite	Malachite
Lapis aerarius	Kupfer ertz		Copper ore
Aes caldarium rubrum fuscum or Aes sui coloris	Lebeter kupfer	When used for an ore, is probably cuprite	*Ruby copper ore
Aes sui coloris	Rotkupfer	When used for an ore, is probably cuprite	*Ruby copper ore
Aes nigrum	Schwartz kupfer	Probably CuO from oxidation of other minerals	*Black copper

In addition to the above the Author uses the following, which were in the main artificial products:

Aerugo	Grünspan oder Spanschgrün	Verdigris	Verdigris
Aes luteum	Gelfarkupfer	Impure blister copper	Unrefined copper (see [note 16, p. 511])
Aes caldarium	Lebeterkupfer	Impure blister copper	Unrefined copper (see [note 16, p. 511])
Aeris flos	Kupferbraun	Cupric oxide scales	Copper flower
Aeris squama	Kupferhammerschlag	Cupric oxide scales	Copper scale (see [note 9, p. 233])
Atramentum sutorium caeruleum or chalcanthum	Blaw kupfer wasser	Chalcanthite	Native blue vitriol (see note on p. [572])

[Pg 110] Blue and green copper minerals were distinguished by all the ancient mineralogists. Theophrastus, Dioscorides, Pliny, etc., all give sufficient detail to identify their cyanus and caeruleum partly with modern azurite, and their chrysocolla partly with the modern mineral of the same name. However, these terms were also used for vegetable pigments, as well as for the pigments made from the minerals. The Greek origin of chrysocolla (chrysos, gold and kolla, solder) may be blamed with another and distinct line of confusion, in that this term has been applied to soldering materials, from Greek down to modern times, some of the ancient mineralogists even asserting that the copper mineral chrysocolla was used for this purpose. Agricola uses chrysocolla for borax, but is careful to state in every case (see [note xx., p. x]): "Chrysocolla made from nitrum," or "Chrysocolla which the Moors call Borax." Dioscorides and Pliny mention substances which were evidently copper sulphides, but no description occurs prior to Agricola that permits a hazard as to different species.

Lead Minerals.

Plumbarius lapis	Glantz	Galena	Galena
Galena	Glantz und pleiertz	Galena	Galena
Plumbum nigrum lutei coloris	Pleiertz oder pleischweis	Cerussite (PbCO₃)	Yellow lead ore
Plumbago metallica	Pleiertz oder pleischweis	Cerussite (PbCO₃)	Yellow lead ore
Cerussa	Pleiweis	Artificial White-lead	White-lead (see [note 4, p. 440])
Ochra facticia or ochra plumbaria	Pleigeel	Massicot (Pb O)	*Lead-ochre (see [note 8, p. 232])
Molybdaena	Herdplei	Part litharge	Hearth-lead (see [note 37, p. 476])
Plumbago fornacis	Herdplei	Part litharge	Hearth-lead (see [note 37, p. 476])
Spuma argenti	Glett	Litharge	Litharge (see note on p. [465])
Lithargyrum	Glett	Litharge	Litharge (see note on p. [465])
Minium secundarium	Menning	Minium (Pb₃O₄)	Red-lead (see [note 7, p. 232])

So far as we can determine, all of these except the first three were believed by Agricola to be artificial products. Of the first three, galena is certain enough, but while he obviously was familiar with the alteration lead products, his descriptions are inadequate and much confused with the artificial oxides. Great confusion arises in the ancient mineralogies over the terms molybdaena, plumbago, plumbum, galena, and spuma argenti, all of which, from Roman mineralogists down to a century after Agricola, were used for lead in some form. Further discussion of such confusion will be found in [note 37, p. 476]. Agricola in Bermannus and De Natura Fossilium, devotes pages to endeavouring to reconcile the ancient usages of these terms, and all the confusion existing in Agricola's time was thrice confounded when the names molybdaena and plumbago were assigned to non-lead minerals.

Tin. Agricola knew only one tin mineral: Lapilli nigri ex quibus conflatur plumbum candidum, i.e., "Little black stones from which tin is smelted," and he gives the German equivalent as zwitter, "tin-stone." He describes them as being of different colours, but probably due to external causes.

Antimony. (Interpretatio,—spiesglas.) The stibi or stibium of Agricola was no doubt the sulphide, and he follows Dioscorides in dividing it into male and female species. This distinction, however, is impossible to apply from the inadequate descriptions given. The mineral and metal known to Agricola and his predecessors was almost always the sulphide, and we have not felt justified in using the term antimony alone, as that implies the refined product, therefore, we have adopted either the Latin term or the old English term "grey antimony." The smelted antimony of commerce sold under the latter term was the sulphide. For further notes see p. [428].

Bismuth*. Plumbum cinereum (Interpretatio,—bismut). Agricola states that this mineral occasionally occurs native, "but more often as a mineral of another colour" (De Nat. Fos., p. 337), and he also describes its commonest form as black or grey. This, considering his localities, would indicate the sulphide, although he assigns no special name to it. Although bismuth is mentioned before Agricola in the Nützliche Bergbüchlin, he was the first to describe it (see p. [433]).

Quicksilver. Apart from native quicksilver, Agricola adequately describes cinnabar only. The term used by him for the mineral is minium nativum (Interpretatio,—bergzinober or cinnabaris). He makes the curious statement (De Nat. Fos. p. 335) that rudis quicksilver also occurs liver-coloured and blackish,—probably gangue colours. (See p. [432]).

[Pg 111] Arsenical Minerals. Metallic arsenic was unknown, although it has been maintained that a substance mentioned by Albertus Magnus (De Rebus Metallicis) was the metallic form. Agricola, who was familiar with all Albertus's writings, makes no mention of it, and it appears to us that the statement of Albertus referred only to the oxide from sublimation. Our word "arsenic" obviously takes root in the Greek for orpiment, which was also used by Pliny (XXXIV, 56) as arrhenicum, and later was modified to arsenicum by the Alchemists, who applied it to the oxide. Agricola gives the following in Bermannus (p. 448), who has been previously discussing realgar and orpiment:—"Ancon: Avicenna also has a white variety. Bermannus: I cannot at all believe in a mineral of a white colour; perhaps he was thinking of an artificial product; there are two which the Alchemists make, one yellow and the other white, and they are accounted the most powerful poisons to-day, and are called only by the name arsenicum." In De Natura Fossilium (p. 219) is described the making of "the white variety" by sublimating orpiment, and also it is noted that realgar can be made from orpiment by heating the latter for five hours in a sealed crucible. In De Re Metallica ([Book X.]), he refers to auripigmentum facticum, and no doubt means the realgar made from orpiment. The four minerals of arsenic base mentioned by Agricola were:—

Auripigmentum	Operment	Orpiment (As₂S₃)	Orpiment
Sandaraca	Rosgeel	Realgar (As S)	Realgar
Arsenicum	Arsenik	Artificial arsenical oxide	White arsenic
Lapis subrutilus atque ... splendens	Mistpuckel	Arsenopyrite (Fe As S)	*Mispickel

We are somewhat uncertain as to the identification of the last. The yellow and red sulphides, however, were well known to the Ancients, and are described by Aristotle, Theophrastus (71 and 89), Dioscorides (V, 81), Pliny (XXXIII, 22, etc.); and Strabo (XII, 3, 40) mentions a mine of them near Pompeiopolis, where, because of its poisonous character none but slaves were employed. The Ancients believed that the yellow sulphide contained gold—hence the name auripigmentum, and Pliny describes the attempt of the Emperor Caligula to extract the gold from it, and states that he did obtain a small amount, but unprofitably. So late a mineralogist as Hill (1750) held this view, which seemed to be general. Both realgar and orpiment were important for pigments, medicinal purposes, and poisons among the Ancients. In addition to the above, some arsenic-cobalt minerals are included under cadmia.

Iron Minerals.

Ferrum purum	Gedigen eisen	Native iron	*Native iron
Terra ferria	Eisen ertz	Various soft and hard iron ores, probably mostly hematite	Ironstone
Ferri vena	Eisen ertz
Galenae genus tertium omnis metalli inanissimi	Eisen glantz
Schistos	Glasköpfe oder blütstein
Ferri vena jecoris colore	Leber ertz
Ferrugo	Rüst	Part limonite	Iron rust
Magnes	Siegelstein oder magnet	Magnetite	Lodestone
Ochra nativa	Berg geel	Limonite	Yellow ochre or ironstone
Haematites	Blüt stein	Part hematite	Bloodstone or
Haematites	Blüt stein	Part jasper	ironstone
Schistos	Glas köpfe	Part limonite	Ironstone
Pyrites	Kis	Pyrites	Pyrites
Pyrites argenti coloris	wasser oder weisser kis	Marcasite	*White iron pyrites
Misy	Gel atrament	Part copiapite	Misy (see note on p. [573])
Sory	Graw und schwartz atrament	Partly a decomposed iron pyrite	Sory (see note on p. [573])
Melanteria	Schwartz und grau atrament	Melanterite (native vitriol)	Melanteria (see note on p. [573])

The classification of iron ores on the basis of exterior characteristics, chiefly hardness and [Pg 112]brilliancy, does not justify a more narrow rendering than "ironstone." Agricola (De Nat. Fos., Book V.) gives elaborate descriptions of various iron ores, but the descriptions under any special name would cover many actual minerals. The subject of pyrites is a most confused one; the term originates from the Greek word for fire, and referred in Greek and Roman times to almost any stone that would strike sparks. By Agricola it was a generic term in somewhat the same sense that it is still used in mineralogy, as, for instance, iron pyrite, copper pyrite, etc. So much was this the case later on, that Henckel, the leading mineralogist of the 18th Century, entitled his large volume Pyritologia, and in it embraces practically all the sulphide minerals then known. The term marcasite, of mediæval Arabic origin, seems to have had some vogue prior and subsequent to Agricola. He, however, puts it on one side as merely a synonym for pyrite, nor can it be satisfactorily defined in much better terms. Agricola apparently did not recognise the iron base of pyrites, for he says (De Nat. Fos., p. 366): "Sometimes, however, pyrites do not contain any gold, silver, copper, or lead, and yet it is not a pure stone, but a compound, and consists of stone and a substance which is somewhat metallic, which is a species of its own." Many varieties were known to him and described, partly by their other metal association, but chiefly by their colour.

Cadmia. The minerals embraced under this term by the old mineralogists form one of the most difficult chapters in the history of mineralogy. These complexities reached their height with Agricola, for at this time various new minerals classed under this heading had come under debate. All these minerals were later found to be forms of zinc, cobalt, or arsenic, and some of these minerals were in use long prior to Agricola. From Greek and Roman times down to long after Agricola, brass was made by cementing zinc ore with copper. Aristotle and Strabo mention an earth used to colour copper, but give no details. It is difficult to say what zinc mineral the cadmium of Dioscorides (V, 46) and Pliny (XXXIV, 2), really was. It was possibly only furnace calamine, or perhaps blende for it was associated with copper. They amply describe cadmia produced in copper furnaces, and pompholyx (zinc oxide). It was apparently not until Theophilus (1150) that the term calamina appears for that mineral. Precisely when the term "zinc," and a knowledge of the metal, first appeared in Europe is a matter of some doubt; it has been attributed to Paracelsus, a contemporary of Agricola (see note on p. [409]), but we do not believe that author's work in question was printed until long after. The quotations from Agricola given below, in which zincum is mentioned in an obscure way, do not appear in the first editions of these works, but only in the revised edition of 1559. In other words, Agricola himself only learned of a substance under this name a short period before his death in 1555. The metal was imported into Europe from China prior to this time. He however does describe actual metallic zinc under the term conterfei, and mentions its occurrence in the cracks of furnace walls. (See also notes on p. [409]).

The word cobalt (German kobelt) is from the Greek word cobalos, "mime," and its German form was the term for gnomes and goblins. It appears that the German miners, finding a material (Agricola's "corrosive material") which injured their hands and feet, connected it with the goblins, or used the term as an epithet, and finally it became established for certain minerals (see [note 21, p. 214], on this subject). The first written appearance of the term in connection with minerals, appears in Agricola's Bermannus (1530). The first practical use of cobalt was in the form of zaffre or cobalt blue. There seems to be no mention of the substance by the Greek or Roman writers, although analyses of old colourings show some traces of cobalt, but whether accidental or not is undetermined. The first mention we know of, was by Biringuccio in 1540 (De La Pirotechnia, Book II, Chap. IX.), who did not connect it with the minerals then called cobalt or cadmia. "Zaffera is another mineral substance, like a metal of middle weight, which will not melt alone, but accompanied by vitreous substances it melts into an azure colour so that those who colour glass, or paint vases or glazed earthenware, make use of it. Not only does it serve for the above-mentioned operations, but if one uses too great a quantity of it, it will be black and all other colours, according to the quantity used." Agricola, although he does not use the word zaffre, does refer to a substance of this kind, and in any event also missed the relation between zaffre and cobalt, as he seems to think (De Nat. Fos., p. 347) that zaffre came from bismuth, a belief that existed until long after his time. The cobalt of the Erzgebirge was of course, intimately associated with this mineral. He says, "the slag of bismuth, mixed together with metalliferous substances, which when melted make a kind of glass, will tint glass and earthenware vessels blue." Zaffre is the roasted mineral ground with sand, while smalt, a term used more frequently, is the fused mixture with sand.

The following are the substances mentioned by Agricola, which, we believe, relate to cobalt and zinc minerals, some of them arsenical compounds. Other arsenical minerals we give above.

[Pg 113]Cadmia fossilis	Calmei; lapis calaminaris	Calamine	Calamine
Cadmia metallica	Kobelt	Part cobalt	*Cadmia metallica
Cadmia fornacis	Mitlere und obere offenbrüche	Furnace accretions or furnace calamine	Furnace accretions
Bituminosa cadmia	Kobelt des bergwacht	(Mannsfeld copper schists)	Bituminosa cadmia (see [note 4, p. 273])
Galena inanis	Blende	Sphalerite* (Zn S)	*Blende
Cobaltum cineraceum		Smallite* (CoAs₂)	Cadmia metallica
Cobaltum nigrum		Abolite*
Cobaltum ferri colore		Cobaltite (CoAsS)
Zincum	Zinck	Zinc	Zinc
Liquor Candidus ex fornace ... etc.	Conterfei	Zinc	See [note 48, p. 408]
Atramentum sutorium, candidum, potissimum reperitur Goselariae		Goslarite (Zn SO₄)	*Native white vitriol
Spodos subterranea cinerea	Geeler zechen rauch	Either natural or artificial zinc oxides, no doubt containing arsenical oxides	Grey spodos
Spodos subterranea nigra	Schwartzer zechen rauch, auff dem, Altenberge nennet man in kis		Black spodos
Spodos subterranea viridis	Grauer zechen rauch		Green spodos
Pompholyx	Hüttenrauch		Pompholyx (see [note 26, p. 394])

As seen from the following quotations from Agricola, on cadmia and cobalt, there was infinite confusion as to the zinc, cobalt, and arsenic minerals; nor do we think any good purpose is served by adding to the already lengthy discussion of these passages, the obscurity of which is natural to the state of knowledge; but we reproduce them as giving a fairly clear idea of the amount of confusion then existing. It is, however, desirable to bear in mind that the mines familiar to Agricola abounded in complex mixtures of cobalt, nickel, arsenic, bismuth, zinc, and antimony. Agricola frequently mentions the garlic odour from cadmia metallica, which, together with the corrosive qualities mentioned below, would obviously be due to arsenic. Bermannus (p. 459). "This kind of pyrites miners call cobaltum, if it be allowed to me to use our German name. The Greeks call it cadmia. The juices, however, out of which pyrites and silver are formed, appear to solidify into one body, and thus is produced what they call cobaltum. There are some who consider this the same as pyrites, because it is almost the same. There are some who distinguish it as a species, which pleases me, for it has the distinctive property of being extremely corrosive, so that it consumes the hands and feet of the workmen, unless they are well protected, which I do not believe that pyrites can do. Three kinds are found, and distinguished more by the colour than by other properties; they are black (abolite?), grey (smallite?), and iron colour (cobalt glance?). Moreover, it contains more silver than does pyrites...." Bermannus (p. 431). "It (a sort of pyrites) is so like the colour of galena that not without cause might anybody have doubt in deciding whether it be pyrites or galena.... Perhaps this kind is neither pyrites nor galena, but has a genus of its own. For it has not the colour of pyrites, nor the hardness. It is almost the colour of galena, but of entirely different components. From it there is made gold and silver, and a great quantity is dug out from Reichenstein which is in Silesia, as was lately reported to me. Much more is found at Raurici, which they call zincum; which species differs from pyrites, for the latter contains more silver than gold, the former only gold, or hardly any silver."

(De Natura Fossilium, p. 170). "Cadmia fossilis has an odour like garlic" ... (p. 367). "We now proceed with cadmia, not the cadmia fornacis (furnace accretions) of which I spoke in the last book, nor the cadmia fossilis (calamine) devoid of metal, which is used to colour copper, whose nature I explained in Book V, but the metallic mineral (fossilis metallica), which Pliny states to be an ore from which copper is made. The Ancients have left no record that another metal could be smelted from it. Yet it is a fact [Pg 114]that not only copper but also silver may be smelted from it, and indeed occasionally both copper and silver together. Sometimes, as is the case with pyrites, it is entirely devoid of metal. It is frequently found in copper mines, but more frequently still in silver mines. And there are likewise veins of cadmia itself.... There are several species of the cadmia fossilis just as there were of cadmia fornacum. For one kind has the form of grapes and another of broken tiles, a third seems to consist of layers. But the cadmia fossilis has much stronger properties than that which is produced in the furnaces. Indeed, it often possesses such highly corrosive power that it corrodes the hands and feet of the miners. It, therefore, differs from pyrites in colour and properties. For pyrites, if it does not contain vitriol, is generally either of a gold or silver colour, rarely of any other. Cadmia is either black or brown or grey, or else reddish like copper when melted in the furnace.... For this cadmia is put in a suitable vessel, in the same way as quicksilver, so that the heat of the fire will cause it to sublimate, and from it is made a black or brown or grey body which the Alchemists call 'sublimated cadmia' (cadmiam sublimatam). This possesses corrosive properties of the highest degree. Cognate with cadmia and pyrites is a compound which the Noricians and Rhetians call zincum. This contains gold and silver, and is either red or white. It is likewise found in the Sudetian mountains, and is devoid of those metals.... With this cadmia is naturally related mineral spodos, known to the Moor Serapion, but unknown to the Greeks; and also pompholyx—for both are produced by fire where the miners, breaking the hard rocks in drifts, tunnels, and shafts, burn the cadmia or pyrites or galena or other similar minerals. From cadmia is made black, brown, and grey spodos; from pyrites, white pompholyx and spodos; from galena is made yellow or grey spodos. But pompholyx produced from copper stone (lapide aeroso) after some time becomes green. The black spodos, similar to soot, is found at Altenberg in Meissen. The white pompholyx, like wool which floats in the air in summer, is found in Hildesheim in the seams in the rocks of almost all quarries except in the sandstone. But the grey and the brown and the yellow pompholyx are found in those silver mines where the miners break up the rocks by fire. All consist of very fine particles which are very light, but the lightest of all is white pompholyx."

Quartz Minerals.

Quarzum ("which Latins call silex")	Quertz oder kiselstein	Quartz	Quartz (see [note 15, p. 380])
Silex	Hornstein oder feurstein	Flinty or jaspery quartz	Hornstone
Crystallum	Crystal	Clear crystals	Crystal
Achates	Achat	Agate	Agate
Sarda	Carneol	Carnelian	Carnelian
Jaspis	Jaspis	Part coloured quartz, part jade	Jaspis
Murrhina	Chalcedonius	Chalcedony	Chalcedony
Coticula	Goldstein	A black silicious stone	Touchstone (see [note 37, p. 252])
Amethystus	Amethyst	Amethyst	Amethyst

Lime Minerals.

Lapis specularis	Gips	Gypsum	Gypsum
Gypsum	Gips	Gypsum	Gypsum
Marmor	Marmelstein	Marble	Marble
Marmor alabastrites	Alabaster	Alabaster	Alabaster
Marmor glarea		Calcite (?)	Calc spar(?)
Saxum calcis	Kalchstein	Limestone	Limestone
Marga	Mergel	Marl	Marl
Tophus	Toffstein oder topstein stalagmites, etc.	Sintry limestones,	Tophus (see [note 13, p. 233])

Miscellaneous.

Amiantus	Federwis, pliant salamanderhar	Usually asbestos	Asbestos
Magnetis	Silberweis oder katzensilber	Mica	*Mica
Bracteolae magnetidi simile
Mica	Katzensilber oder glimmer
[Pg 115]Silex ex eo ictu ferri facile ignis elicitur.... excubus figuris		Feldspar	*Feldspar
Medulla saxorum	Steinmarck	Kaolinite	Porcelain clay
Fluores (lapides gemmarum simili)	Flusse	Fluorspar	*Fluorspar (see [note 15, p. 380])
Marmor in metallis repertum	Spat	Barite	*Heavy spar

Apart from the above, many other minerals are mentioned in other chapters, and some information is given with regard to them in the footnotes.

[9] Three librae of silver per centumpondium would be equal to 875 ounces per short ton.

[10] As stated in note on p. [2], Agricola divided "stones so called" into four kinds; the first, common stones in which he included lodestone and jasper or bloodstone; the second embraced gems; the third were decorative stones, such as marble, porphyry, etc.; the fourth were rocks, such as sandstone and limestone.

Lodestone. (Magnes; Interpretatio gives Siegelstein oder magnet). The lodestone was well-known to the Ancients under various names—magnes, magnetis, heraclion, and sideritis. A review of the ancient opinions as to its miraculous properties would require more space than can be afforded. It is mentioned by many Greek writers, including Hippocrates (460-372 B.C.) and Aristotle; while Theophrastus (53), Dioscorides (V, 105), and Pliny (XXXIV, 42, XXXVI, 25) describe it at length. The Ancients also maintained the existence of a stone, theamedes, having repellant properties, and the two were supposed to exist at times in the same stone.

Emery. (Smiris; Interpretatio gives smirgel). Agricola (De Natura Fossilium, p. 265) says: "The ring-makers polish and clean their hard gems with smiris. The glaziers use it to cut their glass into sheets. It is found in the silver mines of Annaberg in Meissen and elsewhere." Stones used for polishing gems are noted by the ancient authors, and Dana (Syst. of Mineralogy, p. 211) considers the stone of Armenia, of Theophrastus (77), to be emery, although it could quite well be any hard stone, such as Novaculite—which is found in Armenia. Dioscorides (V, 166) describes a stone with which the engravers polish gems.

Lapis Judaicus. (Interpretatio gives Jüden stein). This was undoubtedly a fossil, possibly a pentremites. Agricola (De Natura Fossilium, p. 256) says: "It is shaped like an acorn, from the obtuse end to the point proceed raised lines, all equidistant, etc." Many fossils were included among the semi-precious stones by the Ancients. Pliny (XXXVII, 55, 66, 73) describes many such stones, among them the balanites, phoenicitis and the pyren, which resemble the above.

Trochitis. (Interpretatio gives spangen oder rederstein). This was also a fossil, probably crinoid stems. Agricola (De Natura Fossilium, p. 256) describes it: "Trochites is so called from a wheel, and is related to lapis judaicus. Nature has indeed given it the shape of a drum (tympanum). The round part is smooth, but on both ends as it were there is a module from which on all sides there extend radii to the outer edge, which corresponds with the radii. These radii are so much raised that it is fluted. The size of these trochites varies greatly, for the smallest is so little that the largest is ten times as big, and the largest are a digit in length by a third of a digit in thickness ... when immersed in vinegar they make bubbles."

[11] The "extraordinary earths" of Agricola were such substances as ochres, tripoli, fullers earth, potters' clay, clay used for medicinal purposes, etc., etc.

[Pg 117][12] Presumably the ore-body dips into a neighbouring property.

[Pg 118][13] The various kinds of iron tools are described in great detail in [Book VI].

[14] Fire-setting as an aid to breaking rock is of very ancient origin, and moreover it persisted in certain German and Norwegian mines down to the end of the 19th century—270 years after the first application of explosives to mining. The first specific reference to fire-setting in mining is by Agatharchides (2nd century B.C.) whose works are not extant, but who is quoted by both Diodorus Siculus and Photius, for which statement see [note 8, p. 279]. Pliny (XXXIII, 21) says: "Occasionally a kind of silex is met with, which must be broken with fire and vinegar, or as the tunnels are filled with suffocating fumes and smoke, [Pg 119]they frequently use bruising machines, carrying 150 librae of iron." This combination of fire and vinegar he again refers to (XXIII, 27), where he dilates in the same sentence on the usefulness of vinegar for breaking rock and for salad dressing. This myth about breaking rocks with fire and vinegar is of more than usual interest, and its origin seems to be in the legend that Hannibal thus broke through the Alps. Livy (59 B.C., 17 A.D.) seems to be the first to produce this myth in writing; and, in any event, by Pliny's time (23-79 A.D.) it had become an established method—in literature. Livy (XXI, 37) says, in connection with Hannibal's crossing of the Alps: "They set fire to it (the timber) when a wind had arisen suitable to excite the fire, then when the rock was hot it was crumbled by pouring on vinegar (infuso aceto). In this manner the cliff heated by the fire was broken by iron tools, and the declivities eased by turnings, so that not only the beasts of burden but also the elephants could be led down." Hannibal crossed the Alps in 218 B.C. and Livy's account was written 200 years later, by which time Hannibal's memory among the Romans was generally surrounded by Herculean fables. Be this as it may, by Pliny's time the vinegar was generally accepted, and has been ceaselessly debated ever since. Nor has the myth ceased to grow, despite the remarks of Gibbon, Lavalette, and others. A recent historian (Hennebert, Histoire d' Annibal II, p. 253) of that famous engineer and soldier, soberly sets out to prove that inasmuch as literal acceptance of ordinary vinegar is impossible, the Phoenicians must have possessed some mysterious high explosive. A still more recent biographer swallows this argument in toto. (Morris, "Hannibal," London, 1903, p. 103). A study of the commentators of this passage, although it would fill a volume with sterile words, would disclose one generalization: That the real scholars have passed over the passage with the comment that it is either a corruption or an old woman's tale, but that hosts of soldiers who set about the biography of famous generals and campaigns, almost to a man take the passage seriously, and seriously explain it by way of the rock being limestone, or snow, or by the use of explosives, or other foolishness. It has been proposed, although there are grammatical objections, that the text is slightly corrupt and read infosso acuto, instead of infuso aceto, in which case all becomes easy from a mining point of view. If so, however, it must be assumed that the corruption occurred during the 20 years between Livy and Pliny.

By the use of fire-setting in recent times at Königsberg (Arthur L. Collins, "Fire-setting," Federated Inst. of Mining Engineers, Vol. V, p. 82) an advance of from 5 to 20 feet per month in headings was accomplished, and on the score of economy survived the use of gunpowder, but has now been abandoned in favour of dynamite. We may mention that the use of gunpowder for blasting was first introduced at Schemnitz by Caspar Weindle, in 1627, but apparently was not introduced into English mines for nearly 75 years afterward, as the late 17th century English writers continue to describe fire-setting.

[Pg 127][15] The strata here enumerated are given in the Glossary of De Re Metallica as follows:—

Corium terrae	Die erd oder leim.
Saxum rubrum	Rot gebirge.
Alterum item rubrum	Roterkle.
Argilla cinerea	Thone.
Tertium saxum	Gerhulle.
Cineris vena	Asche.
Quartum saxum	Gniest.
Quintum saxum	Schwehlen.
Sextum saxum	Oberrauchstein.
Septimum saxum	Zechstein.
Octavum saxum	Underrauchstein.
Nonum saxum	Blitterstein.
Decimum saxum	Oberschuelen.
Undecimum saxum	Mittelstein.
Duodecimum saxum	Underschuelen.
Decimumtertium saxum	Dach.
Decimumquartum saxum	Norweg.
Decimumquintum saxum	Lotwerg.
Decimumsextum saxum	Kamme.
Lapis aerosus fissilis	Schifer.

The description is no doubt that of the Mannsfeld cupriferous slates. It is of some additional interest as the first attempt at stratigraphic distinctions, although this must not be taken too literally, for we have rendered the different numbered "saxum" in this connection as "stratum." The German terms given by Agricola above, can many of them be identified in the miners' terms to-day for the various strata at Mannsfeld. Over the kupferschiefer the names to-day are kammschale, dach, faule, zechstein, rauchwacke, rauchstein, asche. The relative thickness of these beds is much the same as given by Agricola. The stringers in the 8th stratum of stone, which fuse in the fire of the second order, were possibly calcite. The rauchstein of the modern section is distinguished by stringers of calcite, which give it at times a brecciated appearance.

[Pg 129][16] The history of surveying and surveying instruments, and in a subsidiary way their application to mine work, is a subject upon which there exists a most extensive literature. However, that portion of such history which relates to the period prior to Agricola represents a much less proportion of the whole than do the citations to this chapter in De Re Metallica, which is the first comprehensive discussion of the mining application. The history of such instruments is too extensive to be entered upon in a footnote, but there are some fundamental considerations which, if they had been present in the minds of historical students of this subject, would have considerably abridged the literature on it. First, there can be no doubt that measuring cords or rods and boundary stones existed almost from the first division of land. There is, therefore, no need to try to discover their origins. Second, the history of surveying and surveying instruments really begins with the invention of instruments for taking levels, or for the determination of angles with a view to geometrical calculation. The meagre facts bearing upon this subject do not warrant the endless expansion they have received by argument as to what was probable, in order to accomplish assumed methods of construction among the Ancients. For instance, the argument that in carrying the Grand Canal over watersheds with necessary reservoir supply, the Chinese must have had accurate levelling and surveying instruments before the Christian Era, and must have conceived in advance a completed work, does not hold water when any investigation will demonstrate that the canal grew by slow accretion from the lateral river systems, until it joined almost by accident. Much the same may be said about the preconception of engineering results in several other ancient works. There can be no certainty as to who first invented instruments of the order mentioned above; for instance, the invention of the dioptra has been ascribed to Hero, vide his work on the Dioptra. He has been assumed to have lived in the 1st or 2nd Century B.C. Recent investigations, however, have shown that he lived about 100 A.D. (Sir Thomas Heath, Encyc. Brit. 11th Ed., XIII, 378). As this instrument is mentioned by Vitruvius (50 - 0 B.C.) the myth that Hero was the inventor must also disappear. Incidentally Vitruvius (VIII, 5) describes a levelling instrument called a chorobates, which was a frame levelled either by a groove of water or by plumb strings. Be the inventor of the dioptra who he may, Hero's work on that subject contains the first suggestion of mine surveys in the problems (XIII, XIV, XV, XVI), where geometrical methods are elucidated for determining the depths required for the connection of shafts and tunnels. On the compass we give further notes on p. [56]. It was probably an evolution of the 13th Century. As to the application of angle- and level-determining instruments to underground surveys, so far as we know there is no reference prior to Agricola, except that of Hero. Mr. Bennett Brough (Cantor Lecture, London, 1892) points out that the Nützliche Bergbüchlin (see [Appendix]) describes a mine compass, but there is not the slightest reference to its use for anything but surface direction of veins.

Although map-making of a primitive sort requires no instruments, except legs, the oldest map in the world possesses unusual interest because it happens to be a map of a mining region. This well-known Turin papyrus dates from Seti I. (about 1300 B.C.), and it represents certain gold mines between the Nile and the Red Sea. The best discussion is by Chabas (Inscriptions des Mines d'Or, Chalons-sur-Saone, Paris, 1862, p. 30-36). Fragments of another papyrus, in the Turin Museum, are considered by Lieblein (Deux Papyras Hiératiques, Christiania, 1868) also to represent a mine of the time of Rameses I. If so, this one dates from about 1400 B.C. As to an actual map of underground workings (disregarding illustrations) we know of none until after Agricola's time. At his time maps were not made, as will be gathered from the text.

[Pg 132][17] For greater clarity we have in a few places interpolated the terms "major" and "minor" triangles.

[Pg 137][18] The names of the instruments here described in the original text, their German equivalents in the Glossary, and the terms adopted in translation are given below:—

Latin Text.	Glossary.	Terms Adopted.
Funiculus		Cord
Pertica	Stab	Rod
Hemicyclium	Donlege bretlein	Hemicycle
Tripus	Stul	Tripod
Instrumentum cui index	Compass	Compass
Orbis	Scheube	Orbis
Libra stativa	Auffsafz	Standing plummet level
Libra pensilis	Wage	Suspended plummet level
Instrumentum cui index Alpinum	Der schiner compass	Swiss compass

[Pg 139][19] It is interesting to note that the ratio of any length so obtained, to the whole length of the staff, is practically equal to the cosine of the angle represented by the corresponding gradation on the hemicycle; the gradations on the rod forming a fairly accurate table of cosines.

[Pg 142][20] It must be understood that instead of "plotting" a survey on a reduced scale on paper, as modern surveyors do, the whole survey was reproduced in full scale on the "surveyor's field."

BOOK VI.

igging of veins I have written of, and the timbering of shafts, tunnels, drifts, and other excavations, and the art of surveying. I will now speak first of all, of the iron tools with which veins and rocks are broken, then of the buckets into which the lumps of earth, rock, metal, and other excavated materials are thrown, in order that they may be drawn, conveyed, or carried out. Also, I will speak of the water vessels and drains, then of the machines of different kinds,[1] and lastly of the maladies of miners. And while all these matters are being described accurately, many methods of work will be explained.

A wedge is usually three palms and two digits long and six digits wide; at the upper end, for a distance of a palm, it is three digits thick, and beyond that point it becomes thinner by degrees, until finally it is quite sharp.

The iron block is six digits in length and width; at the upper end it is two digits thick, and at the bottom a digit and a half. The iron plate is the same length and width as the iron block, but it is very thin. All of these, as I explained in the last book, are used when the hardest kind of veins are hewn out. Wedges, blocks, and plates, are likewise made larger or smaller.

Now earth, rock, mineral substances and other things dug out with the pick or hewn out with the "iron tools" are hauled out of the shaft in buckets, or baskets, or hide buckets; they are drawn out of tunnels in wheelbarrows or open trucks, and from both they are sometimes carried in trays.

I have sufficiently indicated the nature of the miners' iron tools and their vessels. I will now explain their machines, which are of three kinds, that is, hauling machines, ventilating machines, and ladders. By means of the hauling machines loads are drawn out of the shafts; the ventilating machines receive the air through their mouths and blow it into shafts or tunnels, for if this is not done, diggers cannot carry on their labour without great difficulty in breathing; by the steps of the ladders the miners go down into the shafts and come up again.

Hauling machines are of varied and diverse forms, some of them being made with great skill, and if I am not mistaken, they were unknown to the Ancients. They have been invented in order that water may be drawn from the depths of the earth to which no tunnels reach, and also the excavated material from shafts which are likewise not connected with a tunnel, or if so, only with very long ones. Since shafts are not all of the same depth, there is a great variety among these hauling machines. Of those by which dry loads are drawn out of the shafts, five sorts are in the most common use, of which I will now describe the first.

Into the buckets, drawn by these five machines, the boys or men throw the earth and broken rock with shovels, or they fill them with their hands; hence they get their name of shovellers. As I have said, the same machines raise not only dry loads, but also wet ones, or water; but before I explain the varied and diverse kinds of machines by which miners are wont to draw water alone, I will explain how heavy bodies, such as axles, iron chains, pipes, and heavy timbers, should be lowered into deep vertical shafts.

Water is either hoisted or pumped out of shafts. It is hoisted up after being poured into buckets or water-bags; the water-bags are generally brought up by a machine whose water-wheels have double paddles, while the buckets are brought up by the five machines already described, although in certain localities the fourth machine also hauls up water-bags of moderate size. Water is drawn up also by chains of dippers, or by suction pumps, or by "rag and chain" pumps.[12] When there is but a small quantity, it is either brought up in buckets or drawn up by chains of dippers or suction pumps, and when there is much water it is either drawn up in hide bags or by rag and chain pumps.

The next pump has two drums, two rows of pipes and two drawing-chains whose balls lift out the water; otherwise they are like the last pump. This pump is usually built when an excessive amount of water flows into the sump. These two pumps are turned by water-power; indeed, water draws water.

The following is the way of indicating the increase or decrease of the water in an underground sump, whether it is pumped by this rag and chain pump or by the first pump, or the third, or some other. From a beam which is as high above the shaft as the sump is deep, is hung a cord, to one end of which there is fastened a stone, the other end being attached to a plank. The plank is lowered down by an iron wire fastened to the other end; when the stone is at the mouth of the shaft the plank is right down the shaft in the sump, in which water it floats. This plank is so heavy that it can drag down the wire and its iron clasp and hook, together with the cord, and thus pull the stone upwards. Thus, as the water decreases, the plank descends and the stone is raised; on the contrary, when the water increases the plank rises and the stone is lowered. When the stone nearly touches the beam, since this indicates that the water has been exhausted from the sump by the pump, the overseer in charge of the machine closes the water-race and stops the water-wheel; when the stone nearly touches the ground at the side of the shaft, this indicates that the sump is full of water which has again collected in it, because the water raises the plank and thus the stone drags back both the rope and the iron wire; then the overseer opens the water-race, whereupon the water of the stream again strikes the buckets of the water-wheel and turns the pump. As workmen generally cease from their labours on the yearly holidays, and sometimes on working days, and are thus not always near the pump, and as the pump, if necessary, must continue to draw water all the time, a bell rings aloud continuously, indicating that this pump, or any other kind, is uninjured and nothing is preventing its turning. The bell is hung by a cord from a small wooden axle held in the timbers which stand over the shaft, and a second long cord whose upper end is fastened to the small axle is lowered into the shaft; to the lower end of this cord is fastened a piece of wood; and as often as a cam on the main axle strikes it, so often does the bell ring and give forth a sound.

But enough of haulage machines; I will now speak of ventilating machines. If a shaft is very deep and no tunnel reaches to it, or no drift from another shaft connects with it, or when a tunnel is of great length and no shaft reaches to it, then the air does not replenish itself. In such a case it weighs heavily on the miners, causing them to breathe with difficulty, and sometimes they are even suffocated, and burning lamps are also extinguished. There is, therefore, a necessity for machines which the Greeks call πνευματικάι and the Latins spiritales—though they do not give forth any sound—which enable the miners to breathe easily and carry on their work.

There are two different machines for operating, by means of horses, the above described bellows. The first of these machines has on its axle a wooden wheel, the rim of which is covered all the way round by steps; a horse is kept continually within bars, like those within which horses are held to be shod with iron, and by treading these steps with its feet it turns the wheel, together with the axle; the cams on the axle press down the sweeps which compress the bellows. The way the instrument is made which raises the bellows again, and also the benches on which the bellows rest, I will explain more clearly in [Book IX]. Each bellows, if it draws heavy vapours out of a tunnel, blows them out of the hole in the upper board; if they are drawn out of a shaft, it blows them out through its nozzle. The wheel has a round hole, which is transfixed with a pole when the machine needs to be stopped.

The second machine has two axles; the upright one is turned by a horse, and its toothed drum turns a drum made of rundles on a horizontal axle; in other respects this machine is like the last. Here, also, the nozzles of the bellows placed in the conduits blow a blast into the shaft or tunnel.

It remains for me to speak of the ailments and accidents of miners, and of the methods by which they can guard against these, for we should always devote more care to maintaining our health, that we may freely perform our bodily functions, than to making profits. Of the illnesses, some affect the joints, others attack the lungs, some the eyes, and finally some are fatal to men.

Where water in shafts is abundant and very cold, it frequently injures the limbs, for cold is harmful to the sinews. To meet this, miners should make themselves sufficiently high boots of rawhide, which protect their legs from the cold water; the man who does not follow this advice will suffer much ill-health, especially when he reaches old age. On the other hand, some mines are so dry that they are entirely devoid of water, and this dryness causes the workmen even greater harm, for the dust which is stirred and beaten up by digging penetrates into the windpipe and lungs, and produces difficulty in breathing, and the disease which the Greeks call ἆσθμα. If the dust has corrosive qualities, it eats away the lungs, and implants consumption in the body; hence in the mines of the Carpathian Mountains women are found who have married seven husbands, all of whom this terrible consumption has carried off to a premature death. At Altenberg in Meissen there is found in the mines black pompholyx, which eats wounds and ulcers to the bone; this also corrodes iron, for which reason the keys of their sheds are made of wood. Further, there is a certain kind of cadmia[21] which eats away the feet of the workmen when they have become wet, and similarly their hands, and injures their lungs and eyes. Therefore, for their digging they should make for themselves not only boots of rawhide, but gloves long enough to reach to the elbow, and they should fasten loose veils over their faces; the dust will then neither be drawn through these into their windpipes and lungs, nor will it fly into their eyes. Not dissimilarly, among the Romans [22] the makers of vermilion took precautions against breathing its fatal dust.

Stagnant air, both that which remains in a shaft and that which remains in a tunnel, produces a difficulty in breathing; the remedies for this evil are the ventilating machines which I have explained above. There is another illness even more destructive, which soon brings death to men who work in those shafts or levels or tunnels in which the hard rock is broken by fire. Here the air is infected with poison, since large and small veins and seams in the rocks exhale some subtle poison from the minerals, which is driven out by the fire, and this poison itself is raised with the smoke not unlike pompholyx,[23] which clings to the upper part of the walls in the works in which ore is smelted. If this poison cannot escape from the ground, but falls down into the pools and floats on their surface, it often causes danger, for if at any time the water is disturbed through a stone or anything else, these fumes rise again from the pools and thus overcome the men, by being drawn in with their breath; this is even much worse if the fumes of the fire have not yet all escaped. The bodies of living creatures who are infected with this poison generally swell immediately and lose all movement and feeling, and they die without pain; men even in the act of climbing from the shafts by the steps of ladders fall back into the shafts when the poison overtakes them, because their hands do not perform their office, and seem to them to be round and spherical, and likewise their feet. If by good fortune the injured ones escape these evils, for a little while they are pale and look like dead men. At such times, no one should descend into the mine or into the neighbouring mines, or if he is in them he should come out quickly. Prudent and skilled miners burn the piles of wood on Friday, towards evening, and they do not descend into the shafts nor enter the tunnels again before Monday, and in the meantime the poisonous fumes pass away.

There are also times when a reckoning has to be made with Orcus,[24] for some metalliferous localities, though such are rare, spontaneously produce poison and exhale pestilential vapour, as is also the case with some openings in the ore, though these more often contain the noxious fumes. In the towns of the plains of Bohemia there are some caverns which, at certain seasons of the year, emit pungent vapours which put out lights and kill the miners if they linger too long in them. Pliny, too, has left a record that when wells are sunk, the sulphurous or aluminous vapours which arise kill the well-diggers, and it is a test of this danger if a burning lamp which has been let down is extinguished. In such cases a second well is dug to the right or left, as an air-shaft, which draws off these noxious vapours. On the plains they construct bellows which draw up these noxious vapours and remedy this evil; these I have described before.

Further, sometimes workmen slipping from the ladders into the shafts break their arms, legs, or necks, or fall into the sumps and are drowned; often, indeed, the negligence of the foreman is to blame, for it is his special work both to fix the ladders so firmly to the timbers that they cannot break away, and to cover so securely with planks the sumps at the bottom of the shafts, that the planks cannot be moved nor the men fall into the water; wherefore the foreman must carefully execute his own work. Moreover, he must not set the entrance of the shaft-house toward the north wind, lest in winter the ladders freeze with cold, for when this happens the men's hands become stiff and slippery with cold, and cannot perform their office of holding. The men, too, must be careful that, even if none of these things happen, they do not fall through their own carelessness.

Mountains, too, slide down and men are crushed in their fall and perish. In fact, when in olden days Rammelsberg, in Goslar, sank down, so many men were crushed in the ruins that in one day, the records tell us, about 400 women were robbed of their husbands. And eleven years ago, part of the mountain of Altenberg, which had been excavated, became loose and sank, and suddenly crushed six miners; it also swallowed up a hut and one mother and her little boy. But this generally occurs in those mountains which contain venae cumulatae. Therefore, miners should leave numerous arches under the mountains which need support, or provide underpinning. Falling pieces of rock also injure their limbs, and to prevent this from happening, miners should protect the shafts, tunnels, and drifts.

The venomous ant which exists in Sardinia is not found in our mines. This animal is, as Solinus [25] writes, very small and like a spider in shape; it is called solifuga, because it shuns (fugit) the light (solem). It is very common in silver mines; it creeps unobserved and brings destruction upon those who imprudently sit on it. But, as the same writer tells us, springs of warm and salubrious waters gush out in certain places, which neutralise the venom inserted by the ants.

In some of our mines, however, though in very few, there are other pernicious pests. These are demons of ferocious aspect, about which I have spoken in my book De Animantibus Subterraneis. Demons of this kind are expelled and put to flight by prayer and fasting.[26]

Some of these evils, as well as certain other things, are the reason why pits are occasionally abandoned. But the first and principal cause is that they do not yield metal, or if, for some fathoms, they do bear metal they become barren in depth. The second cause is the quantity of water which flows in; sometimes the miners can neither divert this water into the tunnels, since tunnels cannot be driven so far into the mountains, or they cannot draw it out with machines because the shafts are too deep; or if they could draw it out with machines, they do not use them, the reason undoubtedly being that the expenditure is greater than the profits of a moderately poor vein. The third cause is the noxious air, which the owners sometimes cannot overcome either by skill or expenditure, for which reason the digging is sometimes abandoned, not only of shafts, but also of tunnels. The fourth cause is the poison produced in particular places, if it is not in our power either completely to remove it or to moderate its effects. This is the reason why the caverns in the Plain known as Laurentius [27] used not to be worked, though they were not deficient in silver. The fifth cause are the fierce and murderous demons, for if they cannot be expelled, no one escapes from them. The sixth cause is that the underpinnings become loosened and collapse, and a fall of the mountain usually follows; the underpinnings are then only restored when the vein is very rich in metal. The seventh cause is military operations. Shafts and tunnels should not be re-opened unless we are quite certain of the reasons why the miners have deserted them, because we ought not to believe that our ancestors were so indolent and spiritless as to desert mines which could have been carried on with profit. Indeed, in our own days, not a few miners, persuaded by old women's tales, have re-opened deserted shafts and lost their time and trouble. Therefore, to prevent future generations from being led to act in such a way, it is advisable to set down in writing the reason why the digging of each shaft or tunnel has been abandoned, just as it is agreed was once done at Freiberg, when the shafts were deserted on account of the great inrush of water.

END OF BOOK VI.