[pp. 57-73]

THE SUBTERRANEOUS GEOGRAPHY of Derbyshire may be considered, under the three divisions, of limestone, coal, and grit, land: and in the following pages, the tracts of land, where these are found; some general circumstances relating to the dispositions, properties, and probable formation, of the various kinds of strata which compose them, will be stated.

Limestone.— The most extensive tract of this land, is in the north-west part of the county; and may be considered, included within a boundary line, commencing at Hope, and proceeding in a south-westerly direction, on the west side of the Peak Forest, by Buxton to the head of the Dove; and following the boundary of the county on that side, for twelve miles, extends into Staffordshire. In the South, this line commences again, at Thorpe, and proceeding to Ashbourne, Wirksworth, Matlock, Winster, Bakewell, by the East of Stoney Middleton to the North of Hope, where it terminates.

There is also a smaller tract of limestone land; on the East side of the county, forming the ridge from near Hardwicke by Bolsover and Barlborough to the borders of Yorkshire, through which it passes with little interruption, as far as Tinmouth Castle in Northumberland. It spreads also in an easterly direction into the county of Nottingham. There are several detached beds of limestone, situated at Ashover, Crich, Turnditch, in the parish of Duffield, Muggington, Ticknall and Osmaston; none of which, however, exceed two miles, in length or breadth.

Coal: the tract of country where this is found may be included under a line, commencing in the South, at Stanton, on the borders of Nottinghamshire; and proceeding in a north-westerly direction, through Morley to the neighbourhood of Belper, and thence in a zig-zag northerly course, by the west of Pentrich, the East of Dethick; through the parishes of Ashover and Dronfield, to the Yorkshire border. The eastern line enters Derbyshire, from Nottinghamshire, a little to the South of Hardwicke-Hall, and proceeds northwards by Bolsover and Killimarsh; and is bounded by the ridge of limestone, which has been already described as lying in that part. It is said that this tract of coal, which has received the name of the great northern rake, extends even to the borders of Scotland, with the exception of a limestone bed, of three miles in breadth, which interrupts it near Ferry-bridge in Yorkshire.— Coal has also been found at Chinley-hill, near Chapel-en-le-Frith; at Newhall, in the parish of Stapenhill , in Hartington near Buxton; and at Church Gresley, Calke, and Measham, in the southern extremity of the county. But the ground where it is found in these places, is not extensive; as it appears to be no more than three miles in length and two in breadth.

Grit-stone: though this does not comprehend all the county, which does not fall under the two former divisions, it occupies a much greater extent of land than either of them. In the North, and north-west extremity of the county; and through the tracts which lie between the principal beds of coal and limestone, it uniformly prevails; but the most extensive tract of grit-stone is found in the East-moor, which extends, in various breadths, as far South as the town of Derby: small beds appear at Allestry, Mackworth, Langley, and many other places in the county.

To these three subterranean districts may be added a fourth; in which no beds of stone of any kind are to be met with, near the surface. That part of the county lying to the South of a line, drawn through Derby from Ashbourne to Nottinghamshire, (with the exception of those small spots already pointed out) will comprehend this tract.

Strata — "The book of nature," said that ingenious philosopher, Mr. Whitehurst, " is open to all men, written in characters equally intelligible to all nations : but, perhaps, in no part of the world more than in Derbyshire: for amidst all the apparent confusion and disorder of the strata in that mountainous country, there is, nevertheless, one constant invariable order in the arrangement and of their various productions, or impressions, of animal, vegetable or mineral substances."^[1]

"The uppermost stratum, which, for the sake of perspicuity, we shall denominate No. 1, is ARGILLACEOUS GRIT, and its accompanying beds of clay, coal, iron-stone, &c. its thickness is various, according as the surface is more or less uneven. It is an assemblage of sand, and adventitious matter: in a base of argil : fracture, granular: of a dull colour: smell, earthy, when breathed on: does not effervesce with acids: does not take a polish: may be easily scraped with a knife: has often brownish red veins: and is often ferruginous: by exposure to the atmosphere, it decomposes. This stratum generally indicates iron ore, which is frequently found under it in laminæ and nodules. The iron-stone is both sulphureous and argillaceous, but the latter is the most common: it lies in irregular beds; is of a brown colour, and compact nature; smell, earthy; and yields about thirty per cent. The strata of argillaceous grit and iron are generally incumbent on coal, which lies in laminæ, of various quality and thickness, and frequently abounds with pyrites, and argillaceous iron ore in nodules: fracture, generally splintery, laminated; sometimes regular, with a bright gloss, and very brittle: contains much sulphur and petroleum. Between the layers of coal, and frequently incumbent on that substance, are various strata of a schistose clay, called by the different names of under-soil, bind, clunch, hard-stone, metal, plate, &c. according as it is more or less indurated. All these are of unequal thickness; being sometimes only a few inches; at others, several feet. Nodules of iron 0re are frequently found, which easily divide, and shew very fine impressions of plants, flowers, coralloids, and shells. All the strata, indeed, incumbent on coal, whether argillaceous stone, or clay, contain a great variety of impressions of vegetables; and particularly the bamboo of India, striated, and jointed at different distances: the euphorbia of the East Indies ; the American ferns, corn; grass, and many other species of the vegetable kingdom not known to exist in any part of the world in a living state. These vegetable forms, and the strata containing them, are said to be a certain indication of coal, not only in Derbyshire, but in every quarter of the kingdom. The stratum of argillaceous grit may be observed in the vicinity of Smalley, Heanor, Derby, Heage, Alfreton, Carnfield, Chesterfield, and many other places. The surface of the country where it appears, is in general uniform; the hills are nearly regular, and rise by an easy inclination, forming vales of considerable extent.

"No. 2, Coarse SILICIOUS GRIT; composed of granulated quartz, and quartz pebbles, of various sizes, hut seldom exceeding a quarter of an inch in diameter: some retain the sharpness of fragments newly broken; others appear to have been rounded by attrition. This stratum is about 120 yards in thickness, and variable both in appearance and texture: near the surface it is very friable, and not unfrequently contains adventitious matter. It gives fire with steel, resists acids, and is often coloured by iron: fracture, irregular; does not take a polish. It is not stratified, but contains varieties of gritstone in laminæ : some are called free-stone, and employed for buildings: others are termed mill-stone grit, and used for mill-stones. A particular variety is laminated with mica, and is somewhat elastic: it easily divides with a knife, and being an excellent substitute for slate, has become an article of commerce: this stratum is not productive of minerals; but there are some instances of lead ore having been found in it; frequently it contains chrystallized fluor, and barytes, and is incumbent on shale or schistus, from which it is separated by a thin seam of clay. This substance forms long and narrow mountains, rather than hills; it is uppermost at Wirksworth Moor; Cromford Moor, near Winster; the East Moor; Birchover, Matlock Town; the Edge-side Hills; from Eyam to Castleton, and various other places. No impressions either of animal or vegetable figures have been discovered in it.

"No. 3, SHALE, or SCHISTUS; of a dark brown, or blackish colour, bituminous, and appearing like indurated clay. Its thickness, according to the respective measurements of Mr. Whitehurst and Mr. Ferber, varies from 120 to 150 yards. This stratum is not considered as generally productive of minerals; though iron-stone in nodules, and thin beds, has sometimes been found in it: and also veins of lead ore: the latter arise from the limestone, on which the shale is incumbent, but become less and less mineralized as they ascend. In its sparry veins are frequent cavities, called lochs by the miners, which are incrusted with a great variety of fine and rare crystallizations of calcareous spar. It contains no impressions either of animal or vegetable bodies: but impressions of marine substances are sometimes discovered in it, much impregnated with pyrites. By exposure to the atmosphere, this shale decomposes in laminæ : its fracture is dull: it absorbs moisture: contains sulphur, burning with a blue flame, and becoming of a reddish-brown colour : frequently resists acids: but sometimes effervesces slowly, and more quickly as it approaches the limestone, from which it is separated by a thin bed of clay: in some cases it even contains a large portion of calcareous earth : the limestone, in return, partaking of its dark colour, to the depth of several feet to where they are in contact. The waters passing through it are chalybeate, and frequently warm. Shale most commonly appears uppermost in vallies formed by limestone mountains on one side, and gritstone on the other, where it is gradually covered with ratchet, a name given to a confused mass of loose, irregular stoney substances, that has probably been composed of shattered pieces, fallen from the adjoining eminences.

"No. 4, —LIMESTONE regularly stratified, but varying considerably in thickness, being in some places not more than four fathoms, yet in others upwards of 200. This stratum seems wholly composed of marine exuviœ , and abounds with a variety of shells, entrochi, coralloids, and many other species of crustaceous animals. In it are found the principal veins or fissures which contain galena, sulphuret, and native oxyde of zinc, a variety of ochres, barytes, calcareous crystallizations, pyrites, &c. It lies in laminæ, more or less thick, and is frequently separated, at irregular distances, by a marl, containing adventitious substances; in some places only a few inches thick ; but in others two or three feet. This limestone forms a variety of beautiful marbles, some black; others of a brown red, much used for chimney-pieces, and different ornaments; some mottled grey; and some of a light stone colour. All the varieties have a fœtid smell, when rubbed with a harder substance: when calcined, they become white, and compose a strong cement. The limestone in the Peak Forest is regarded as the best: it is compact, and sonorous when struck; its fracture, scaly bright. It is much used for the purposes of agriculture, and burns to a fine white lime, losing nearly thirty per cent. of the carbonic gas during the operation, which occupies about thirty hours in a strong fire. On the surface of this stratum, rotten-stone is sometimes found, particularly near Wardlow Mire and Ashford : it is generally accompanied with a silicious substance, in nodules, called chert, which is likewise found in large detached masses, and thin strata, within the limestone. This substance is full of marine figures, and animal remains: its origin has been commonly attributed to a partial dissolution of the limestone stratum. The forms and general appearance of the limestone mountains are greatly diversified; they exhibit evident marks of interior convulsions of the earth, which have dislocated and thrown the strata near the surface into every variety of confusion. In many parts they are perpendicular, and overhanging; presenting bare and rugged forms, and pursuing the wildest directions. Various openings or caverns, locally termed shakes, or swallows, exist in the limestone : these are large fissures, the depth and communications of which cannot be ascertained; yet they have been rendered of great service in several mines, through being made receptacles for the deads, or rubbish ; and have also been appropriated as aqueducts to carry off the water. This stratum is uppermost at Winster, Ashford, Eyam, Buxton Hills, Moneyash, the southern vicinity of Castleton and various other places.

"No.5.—TOADSTONE; a substance exceedingly irregular in appearance, thickness, and disposition; not laminated, but consisting of one entire mass, and breaking alike in all directions. It is sometimes of a dark brown colour, with a greenish tinge, and superficially full of holes; but at a greater depth more compact: sometimes filled with calcareous spar, and sometimes with green globules:—this variety is apparently in a state of decomposition: the fracture irregular. Other varieties have the appearance of basalt, or whin-stone, and are of equal hardness; they contain hornblende, with patches or streakes of red jasper : some specimens, found near Buxton, contain zeolite, and calcedony. These varieties assume so many different characters, according to their various states of decomposition, that their primitive qualities are difficult to be traced. The exterior, or what has been exposed to the atmosphere, resembles a scoria, or vitrified mass: the fracture of a dull colour; earthy smell when breathed on. 'Toadstone,' observes Mr. Whitehurst, contains bladder holes, like the scoria of metals; or Iceland lava, and has the same chemical property of resisting acids. It does not produce any minerals, nor figured stones, representing any part of the animal or vegetable creation; nor are any adventitious bodies enveloped in it: neither does it universally prevail, as the limestone strata ; nor is it like them, equally thick; but in some instances varies in thickness, from six feet to 600. It is likewise attended with other circumstances, which leave no doubt of its being as much a lava as that which flows from Hecla, Vesuvius, or Etna. This substance forms the surface in many parts of the county, beginning in the neighbourhood of Matlock, and dividing the limestone for a considerable distance: near Buxton, and particularly at Wormhill in that neighbourhood, it is of considerable extent, uneven and rocky: but far less so than the preceding stratum. The miners in different parts of Derbyshire distinguish it by the various names of black-stone, channel, cat-dirt and black clay; but the same appellations are very frequently given to substances which scarcely resemble toadstone in any respect but colour; hence, mistakes have arisen, and properties have been attributed to it which it does not possess.

"No. 6.—LIMESTONE of the same qualities as No. 4, and productive of similar minerals and figured stones: below this, no miners in Derbyshire have yet penetrated. It should be remarked, that, vegetable forms have never yet been discovered in any of the limestone strata."^[2]

Though the above be, the general disposition of the strata, yet in particular instances, this order is diversified, and the numbers multiplied. The inferior measures are not always arranged with equal regularity; sometimes they separate each stratum, the thickness differing from three inches to three feet, and appearing of various colours, from the ochre yellow to the brown and ash green; small pieces of pyrites are generally found in them.

Of the toadstone, of which no more than three beds have been discovered in any part of the county, there are some peculiar circumstances worthy notice. The mineral veins, or fissures, in the limestone strata are always cut off and intersected by this substance, when it alternates with the limestone. For when a vein is exhausted in the first bed, that is, in the first black limestone; the ore disappears on reaching the toadstone, and no vestige of it is found, until the bed of toadstone is entirely dug through. The toadstone also, so completely separates the different strata of limestone, that, though the gallery over the miners' heads be inundated, yet they can carry on their work undisturbed by the water, so close is the texture, and so free from fissures, is this substance. Another peculiarity of the toadstone, is, that it is found to fill up the fissures in the limestone strata, immediately under it, in proportion to their width.

These peculiar circumstances attending the toadstone have led Mr. Whitehurst to believe, that it was formed by a different law from others; and that the origin of its formation, was greatly posterior to them. He supposed that the substances that go under the names of toadstone, channel, cat-dirt and black-clay, is actual lava. He imagined that a central fire must at some former time have existed, which by its expansive force, elevated and burst the strata, and threw them into their present state of disorder and confusion. "Fissures being thus opened over the melted matter, the violent pressure might cause it to ascend, till it met an obstruction superior to the impelling force; and the lava being thus circumstanced, would consequently have a proportional lateral pressure, and might therefore penetrate between the strata, and force its way till it lost its fluidity by the coolness of the adjacent beds. Being thus extended to some distance, and passing over other fissures, it might fill them up more or more or less wide, and the lava more or less fluid."^[3] This seems to be confirmed, by the discovery, that the stratum of clay lying under the toadstone, is burnt to the colour of a brick for near a foot in thickness. This hypothesis, however, has been controverted by M. B. Faujas St. St. Fond,- a member of the National Institute at Paris; who says, that this substance is no other than that known on the continent by the name of trapp. But Mr. Mawe, has re-examined the mine visited by M. St. Fond, and seems to think, that, that respectable geologist was deceived by the ignorance or imposition of the miners; and that the toadstone is as much a lava, as that which flows from Hecla, Vesuvius, or Etna.

It has been observed, that the position of the strata is governed by a uniform law; their declination always tending towards those parts of the country, where the grit-stone has appeared on the surface; but the degree of their dipping is various and irregular. In some places they dip at the rate of six inches in a yard; in others twelve, and even eighteen in a similar space. In particular places, this dipping seems to be much influenced by the vallies; the strata on one side being nearly horizontal; while on the opposite they have an oblique, and sometimes perpendicular direction. At Chesterfield and Heanor, the strata have a peculiar position. They dip for a considerable space towards one common centre, and by this means form a kind of bason, or deep circular figure.

The strata of clay-stone land, yielding coal, are found to be exceedingly various in their Order, thickness, and quality. They are in general composed of different sorts of clay, smut or soft coal, bind, black shale, clunch, and hard coal. The position of these strata is very seldom found horizontal, but dip in almost every direction.

[p. 73]

Having thus taken a cursory view of the subterraneous geography of the county, and briefly described the different strata; we come to treat of its minerals and mines. These are provinces which afford ample room for investigation: at all times the mineral kingdom is worthy inspection; and as its productions are not only to be met with, in great variety in Derbyshire, but as they constitute a very great part of its natural riches, it will deserve particular attention.

[pp. 73-91]

Lead.— The lead mines in Derbyshire appear to have been worked in very early times: Camden is of opinion, that Pliny alludes to this county, when he says, "in Britain, on the surface of the ground, lead is dug up in such plenty, that a law was made on purpose to stint them to a set a quantity.^[4]" But whether this be the case or not, it is certain that lead mines were known and worked in the time of the Romans; as several pigs have been found, at different times, with Roman inscriptions on them.

The first of these was accidentally discovered by a labouring man in 1777 on Cromford Moor, lying in an oblique direction, about a foot beneath the surface of the ground. It was purchased by a gentleman in the neighbourhood, for a trifling sum of money, and is now lodged in the British Museum. It bears the inscription IMP. CAES. HADRIANI. AUG. MEI. LVI; which has been interpreted;^[5] The sixth legion inscribes this in memory of the Emperor Hadrian.

[Details of the two pigs of lead found in Matlock and described by Davies, can be found on Lead Mining in Matlock & Matlock Bath in the Matlock section of this website, so are not repeated here.]

These different inscriptions afford undoubted evidence, that the lead mines in the neighbourhood of these places, were worked by the Romans : and it is very probably, that from that time to the present, none of the different nations who inhabited Britain were ignorant or negligent of the treasure. We have reason to believe, that the Saxons and Danes, who, immediately succeeded the Romans, availed themselves of this source of national wealth ; as one of the mines in the neighbourhood of Castleton, is called Odin, the name of one of their northern deities : and this name, also proves that the mine was opened before the prevalence of the Christian Religion.

Dugdale says,^[6] that Eadurga, abbess of Repton, in 714 sent a leaden coffin to St. Guthlac, patron-saint of Croyland Abbey, who died in that year : and in the year 835 Kenewara, another abbess of Repton, granted her estate at Wircesworth, to Humber, the Alderman, on condition, that he gave lead to the value of 300 shillings, to archbishop Ceolnoth, for the use of Christ Church at Canterbury ; so that lead have been in common use and well known before those times. The Castle of the Peak, built as early as the time of William the Conqueror, appears from a survey taken in queen Elizabeth's time, to have been covered with lead. In Doomesday-book mention is made of three lead mines at Wirksworth, one at Crich, one at Bakewell, and another at Metesford, a manor which is described as situated in the neighbourhood of Matlock.

In the sixteenth year of Edward I. Reginald de Leye and William de Meynell, were appointed by the crown, the make enquiry " concerning the liberties which the miners of the High Peak, claim to have in those parts, and which they have hitherto used : and how, and what manner, and from what time and by what warrant. " At the proper time and place, the privileges of the miners were enquired into, and confirmed to them. These are contained in sixty-four articles of the High Peak Hundred ; and fifty-three for the Wapentake of Wirksworth.

The regulations respecting the rights of the miners are numerous and various. Two great courts are to be held every year ; at Easter and Michaelmas : and if required may be called every six weeks.^[7] Those of the High Peak are held at Moneyash ; and those of the Wapentake at Wirksworth. At these courts a Bar-master presides;^[8] who with twenty-four jurymen determines all disputes that may arise among the miners. The Bar-masters are chosen by his Majesty's farmers of the mineral duties:^[9] these have from time immemorial, been let on lease. The present farmer of those in the High Peak is, the Duke of Devonshire ; and those in the Wapentake of Wirksworth, is, Mrs. Rolles. They have a steward each, and Bar-masters in the districts which they hold of the crown.

The duties of the Bar-Master, are various and perplexing : his principal office is to put the miners in possession of the veins they have discovered ; and collection the portion of ore due to the lessee. When a miner has discovered a vein of ore, in any part of the king's field, he may obtain exclusive title to it, if it be not in an orchard, garden, high road or dwelling--house.^[10] Possession is to be given by the Barmaster in the presence of two jurymen, marking in a pipe or rake work two meares of ground, each containing twenty-nine yards; and in a flat work, fourteen yards square. But should a miner neglect to avail himself of his discovery, beyond a given time: then, the Bar-master may take possession of the vein, and dispose of it to another. The Bar-master is also to superintend the admeasurement of the ore, and to receive the dues of the lessee of the crown : this part of the office is attended with some difficulty, from the various claims, which differ greatly in different places. By the articles, a thirteenth of the ore is due to the king ; but there is seldom more than a twenty-fifth taken. There is also a due for tythe : and another called cope, which is paid by the buyer. In mines which are private property, such tolls are paid as the parties agree upon.

The ore is measured out in a dish, containing in the High Peak sixteen pints ; but only fourteen in the Low Peak. The brazen dish, by which the measures in the Low Peak are regulated, appears from the inscription upon it, to have been cast in the reign of Henry VIII. —"This dishe was made the iiij day of Octobr the iiij yere of the Reine of Kynge Henry the viij before George Erle of Shrowsesbury Steward of the Kyng most Honourable household and also Steward of all the honour of Tutbury by the assent and consent as wele of all of the Mynourrs as of all the Brenners within and adioynyng the Lordshyp of Wyrkesworth Percell of the said honour This Dishe to Remayne In the Moote hall of Wyrkesworth hnging by a Cheyne so as the Mchanntes or Mynours may have resorte to the same att all tymes to make the trw Mesure at the same."

The articles before alluded to, contain many privileges which the miners strenuously contend for. By article XIV. The Bar-Master or his deputy, is to lay out a road for the miners to go and come from their work ; and also for carrying to and from their work the running water to wash the ore. This is done in the following manner: —The Bar-master takes with him two of the twenty-four jury men, and walking between them, with his arms and their arms extended, they walk from the mine, to the most convenient place, they can soonest come to the king's high road, pricking down pegs or stakes on each side as they go along; and within those stakes, the miner may carry to, and from, the mines, whatever and wherever he pleased: even if it was standing corn.^[11] By article XLIV. it is provided, " that if any miner be killed or slain, or damped upon the mine, within any groove : neither Escheator, Coroner, nor other officer, ought to meddle therewith, but the Bar-master or his Deputy." By article XIII. it is enacted, that no person ought to sue any miner for debt, that doth belong unto the mines, in any court but the mineral court ; and if any person do the contrary, he shall lose his debt, and pay the charge in the law." By article XXXII. it is provided that "no officer ought to trespass or debt, to execute or serve any writ, warrant, or precept, upon any miner being at his work in the mine ; nor when the miners come or go to the Barmote Court, but the Bar-master, or his deputy only. " By article XLVIII. It is also enacted, " that if any person or persons, feloniously take away any iron ore, or other materials from the groove, shaft or meare of ground, houses, coves, or smelting-houses, or elsewhere ; if it be under the value of thirteen-pence halfpenny, the Bar-master shall punish the offender in the stocks, or otherwise, as it is fit for such offenders to be punished. But if the ore or other materials, be above thirteen-pence halfpenny in value, then we say it is felony."

The method of discovering veins of lead ore is various ; but the practical miner is lead to believe, where a vein is likely to be found, by the nature and quality of the ground and stone: and as most veins are situated in the bowels of the earth, have some branch that proceeds from the main vein, nearly to the surface of the earth, he need only turn up a little of the earth to be satisfied.

[Dugdale's and Pilkington's description of the veins can be found on Lead Mining in Matlock & Matlock Bath in the Matlock section of this website under Nineteenth century lead mines.]

The lead ore in Derbyshire, like that found in most other places, contains silver ; but not a sufficient quantity, to repay the expences attendant on the separation. This was found, by the attempts that were made, some years ago, to extract it ; but the event not answering the expectations of those who were engaged in it, the object was given up, and no such works now exist in the county.

The lead ore most commonly found here, is that known by the name galena : it lies generally in larger and smaller veins and masses ; frequently in nodules with cauk—another name for barites. One sort of galena is found crystallized in cubes, with the angles truncated ; this is of a bright lustre and flaky fracture. —There is another variety, which, when broken, is remarkably bight and foliated; and by exposure to the atmosphere becomes tarnished and decomposes. Another kind of galena, from it being very hard, is called the steel-grained led ore: this when broken, has a granule appearance, resembling the fracture of steel. Small holes, with their surfaces black, as if corroded, are frequently observed, in the masses of galena. Carbonate of lead is sometimes seen on it, in various forms and states: —some of the crystals appearing semi-metallic, others a dirty white, and some transparent. The prism and the double hexagonal pyramids, joined at the base, are the most general shapes.

"Silkenside, is a singular variety of galena, of a bright metallic lustre, with a reflection approaching that of a mirror. It appears thinly plated on one side of a substance called kevel or keble, and usually forms the side of a vein, or cavity; but sometimes composes of a kind of double vein, the smooth surface on each side being closely in contact, though without the least degree of cohesion. When pierced by the miner's tool, or divided by a sharp iron wedge, it first begins to crackle, and in a few minutes rends with considerable violence, exploding with a noise as if blasted with gun-powder. The miners are sometimes wounded by the fragments, when, regardless of the danger, they neglect to retreat sufficiently early ; in these cases, they are often cut violently, as if they had been stabbed in various places with a chisel. This extraordinary phenomenon, has never been satisfactorily explained : its occurrence is chiefly confined to the Haycliff and Lady-wash mines at Eyam, and the Odin mine at Castleton. In the former a prodigious explosion happened in the year 1738 : at Which time Mr. Whitehurst affirms, the quantity of 200 barrels of minerals were blown out at one blast ; each barrel being supposed to contain, three and four hundred weight. During the explosion, the surface of the ground was observed to shake, as if by an earthquake. "^[12]

A variety of carbonate lead sometimes occurs, not adhering to the galena. Masses of a horn colour, semi-transparent, and crystallized on the surface, have been found ; and other carbonated nodules, easily reduced to a sandy powder, are often found in loose ferruginous earth. There is an argillaceous variety, called wheat-stone found in a large vein : this, in general, contains arsenic ; is of a light stone colour, heavy, with black spots. It is not transparent : the fracture earthy, with a few metallic scales : this is extremely easy of fusion, and during the operation it emits a strong smell of sulphur and arsenic. Phosphate of lead, of a leek green colour, in hexagonal prisms, is sometimes discovered on barytes attached to a sand stone. Nolybeate of lead, of a fine yellows colour, sometimes appears in the cavities of galena, and of carbonated lead; but this variety is not often met with.^[13]

The miners have four terms by which they denominate their ore, according to its quality :

[These four are also mentioned on Lead Mining in Matlock & Matlock Bath : Nineteenth century lead mines in the Matlock section of this website.

The ore being thus prepared, is taken to the smelting furnaces. In former times, the business of smelting ore into lead, was accomplished by means of wood fires; and on the western side of the highest hills in the neighbourhood of Wirksworth and Crich, the work was carried on from time immemorial. But this imperfect method was laid aside, and followed by a mode of smelting, which though rude and defective, was an improvement upon it.—The hearth furnace, consists of large rough stones, placed so as to form an oblong cavity, about two feet wide, fourteen long, and two deep ; into which fuel and ore are put in alternate layers : the heat is raised by a large pair of bellows. The fuel is wood and coal ; and when the heat becomes sufficient to smelt the ore the lead runs out into an opening in the front of the furnace, into a trough placed before the hearth ; from whence it is conveyed into moulds, and cast into blocks, called half-pigs. This lead is very soft, pure, and ductile ; but owing to the imperfection of this manner of smelting, a considerable quantity of metal remains mingled with the slags : there are therefore thrown again into the furnace, and the metal disengaged from them, by a powerful fire of cokes : but the lead produced by this second process, is inferior in quality to the former.

At present, however, there is but a small portion of ore smelted in this way : and the hearth. has almost entirely given place to the introduction of the copula furnace. The copula furnace, invented by a physician named Wright, is of an oblong form, resembling a long, but not very deep chest; the top and bottom being a little concave. The fire being placed upon iron bars, at the height of three or four feet, at one end, and a chimney being built at the other extremity ; the flame is drawn over the ore placed in the body of the furnace, and by its reverberation, smelts it without coming into contact with the fuel. One of these furnaces will hold a ton of ore ; but the usual charge is about eighteen hundred weight. The time required for fusing this quantity, is indeterminate ; as some kinds of ore will be ready in six hours, while others require seven, eight, or nine, according to the nature of the substances attached to them. That which is united to spar, is the most easy of fusion ; and it is customary, sometimes, to throw a small quantity of this mineral into the furnace, to accelerate the progress ; but in general, the minerals are combined with the ore, assisted by a little coal slack, are sufficient to smelt it. The lead, after it is smelted, is poured into moulds of various sizes ; for the blocks are of different weights, according to the markets for which they are intended : either Hull, Bawtry, or London. Two of these blocks make a pig, and eight pigs make a fodder.

Bu all the lead in Derbyshire, is not disposed of in this state or form. A portion of it is rolled, in works erected for the purpose, in the neighbourhood of the furnaces, into sheets of various uses. A considerable quantity is, also, converted into Red Lead, by the merchants and smelters, who reside in different parts of the county. This process is accomplished in a kind if oven, having its floor divided into three apartments : the middle one contains the metal, and the two others the fire. The heat is reverberated from the roof on the metal, and converts it into a calx or powder. —Great care is requisite for the due regulation of the heat : but with the nicest adjustment, it seldom happens that the metallic principle, is entirely destroyed by the operation : it therefore becomes necessary, to separate the calcined part from it ; for this purpose, it is ground very small in a mill, and then washed. After that, the calcined part is again exposed to the heat of the furnace, and being continually stirred, acquires a red colour, and is fit for use.

The annual produce of lead from Derbyshire mines, is not exactly ascertained: but may be estimated at an average, between five and six hundred tons. It is generally thought to be on the decline : some of the richest mines being either exhausted, or become more difficult to work; but on the other hand, from the improvements in the art of smelting, and the more effectual methods employed to clear the mines of water, by new levels and improved fire engines; advantages have been gained, that may perhaps supply the deficiency.^[14]

The greatest impediments, that the miners find in working the mines, are foul air and water. To relieve them from the first, a pipe or tube is generally introduced down the shaft, and extended along the roof of the gallery, to the place where the miners are at work ; and thus a free circulation of air is obtained. Many adits, or as they are here called, soughs, have been opened from the bottom of some neighbouring valley, and made to communicate with the works by different channels or galleries, for the purpose of carrying off the water. The most considerable adit in Derbyshire is at Youlegrave, running from the Derwent to Alport; and called the Hildcar Sough. It is two miles in length, and was driven at the expence of £30,000. The miners pay a certain proportion of lead ore to the proprietors as a duty; but as they have now penetrated below the level of the adit, their works are but ineffectually drained by it. But the relieving of the mines at Wirksworth, is only a secondary object of this adit at present; as the water delivered by it at Cromford, has proved of very great value :—The stream is employed in working the extensive cotton works, that are carried forward at that place; and as it is not liable to any considerable increase or diminution, it has proved to be of very great advantage.

There is another sough driven from the level of the Derwent, and is called Wirksworth Moor sough : — it is situated to the East, of that town, and nearly three miles in length. It has been observed, that a low level, in the limestone, drains a large tract of country; all waters falling into it for a considerable distance.^[154]

The second part of this chapter on Subterraneous Geography, Mines and Minerals, &c. continues on on Underground (2)

^[1] Enquiry, &c. into the Formation of the Earth.

^[2] Beauties of England, III. p. 310.

^[3] Whitehurst's Enquiry.

^[4] Camden, p.494. Enquiry.

^[5] By Mr. Pegge in Archaelog. Vol. IV.

^[6] Mon. Angl. V. I., p.88.

^[7] Article XVI.

^[8] Art. Agreed to at the Great Court Bar-mote 1665.

^[9] Note to Art. I.

^[10] Article XVI.

^[11] Miner's Guide, p.34.

^[12] Beauties of England, p.324.

^[13] Mawe's Minerology.

^[14] Aikin's Descrip, p. 81.

^[15] Beauties of England, III. p. 302.

An Ann Andrews book transcript