learning anb JTabor. $ LIBRARY M OF THE # University of Illinois. | CLASS. BOOK. VOLUMK. 355.1 H39 1 Books are not to be taken from the Library. m Accessions No... 3A533 4 HAY a 1965 dUh 4 1255 * METALLIFEROUS DEPOSITS, AND ON SUBTERRANEAN TEMPERATURE; V* FORMING THE EIGHTH VOLUME OF THE TRANSACTIONS OF THE ROYAL GEOLOGICAL SOCIETY OF CORNWALL. PART THE FIRST. BY WILLIAM JOKY KENWOOD, F.R.S.; F.G.S.; »v V MEMBER OF THE GEOLOGICAL SOCIETY OF FRANCE; PRESIDENT OF THE ROYAL INSTITUTION OF CORNWALL ; HONORARY MEMBER OF THE YORKSHIRE PHILOSOPHICAL SOCIETY ; CORRESPONDING MEMBER OF THE IMPERIAL AGRICULTURAL AND NATURAL HISTORY SOCIETY—LYONS, AND OF THE LYCEUM OF NATURAL HISTORY—NEW YORK ; SOMETIME HER MAJESTY’S ASSAY-MASTER OF TIN IN THE DUCHY OF CORNWALL. PENZANCE: Printed and Published by WILLIAM CORNISH, Green Market. 1871 . 1 1 V * « fr vv > l» 'r\ • ‘ ROYAL OF CORNWALL. PATRON. Her Most Gracious Majesty QUEEN VICTORIA. VICE-PATRON. His Royal Highness The PRINCE OF WALES, DUKE OF CORNWALL, K.G., F.R.S.,1 &c., &c., &c., &c. TRUSTEES OF THE MUSEUM. Thomas Simon Bolitho, Esq. John Samuel Enys, Esq., F.G.S. Day Perry Le Grice, Esq., M.A. OFFICERS AND COUNCIL. 1869 — 1870 . PRESIDENT. Hugh Seymour Tremenheere, Esq., M.A., F.G.S., &c., &c. VICE PRESIDENTS. The Viscount Falmouth. SirEdwd. Smirke, V.W., &c., &c. Samuel Higgs, Esq. Robert Tweedy, Esq. SECRETARY. John Hallet Batten, Esq., F.R.G-.S., M.R.A.S., &c., &c. TREASURER. William Bolitho, Jun., Esq. LIBRARIANS. Edward Hearle Rodd, Esq. | Charles Campbell Ross, Esq. CURATOR. George Bown Millett, Esq., M.R.C.S. THE COUNCIL. J. S. Bickford, Esq. Francis Boase, Esq., M.R.C.S. Edward Bolitho, Esq. Thomas Simon Bolitho, Esq. John Richards Branwell, Esq. J. C. Daubuz, Esq. N. B. Downing, Esq. A. L. Fox, Esq. Charles Fox, Esq. D. P. Le Grice, Esq., M.A. T. R. Polwhele, Esq., M.A., F.G.S. John St. Aubyn, Esq., M.P. ft ) Observations on Metalliferous Deposits . By William Jory Henwood, F.R.S.; F.G.S.; Member of the Geological Society of France; President of the Royal Institution of Cornwall; Honorary Member of the Yorkshire Philosophical Society; Corresponding Member of the Imperial Agricultural and Natural History Society—Lyons, and of the Lyceum of Natural History — New York; sometime Her Majesty’s Assay-Master of Tin in the Duchy of Cornwall; Member of the Society. NORTH-WESTERN INDIA. Kumaon and Gurhwal. —The granite of Dwarra Hath, Almora, and Deo Dhoora—although surrounded by metalliferous rocks—is, it¬ self, barren. The micaceous, talcose, and chloritic slates are inter¬ laid—by various ores of copper (I.) at Kurrye (a.), Rai and Bellar (b.), Goron (c.), Seera ( d .), PoTcree (e,f, g , h.f and Al Agur («.); —and with iron-ores (II.) at Sahloo ( a .), Agur (b.), Luttea Garh (c.), Bunna ( d .), Shealgarh , Guarcoolee, Lusghanee, Nutoa Kanh , Galla, Dhoora Kanhi , Capud , Choocootd, Bunnd, Purturburd, &c., («.). The talcose and clay-slates, at and near their union, include conformable beds charged with copper-ore, at Seera ( d .), and PoTcree ( g .). The clay-slates of Pahlee (/.), Pahlee in Kalee Kumaon (< 7 .), Mungla LeJch (A), Tilpoora and Simul Khet («.), contain similar deposits of iron-ore; and in the same series graphite is obtained at Dol. Clay-slate and calcareo-siliceous breccia are separated by a band of iron-ore at Burrulgaon (i\); and the same breccia, together with a calcareo-siliceous conglomerate by which it is succeeded, are overlaid by similar iron-ore at Rampoore (i). At Khuloa-garh and Hurchinolee (j.) calcareous slates are charged, and at Tutyl ( Jc .) they alternate, with iron-ore. In the calciferous slate and siliceous limestone of Dhunpoore ( j .) the ores of copper are mostly determined to the joints. Calcareo-siliceous rocks are impregnated with copper-ore at Tarag-Tce-tal ( Tc .) and with the ores of iron at Oojowlee (m.), Kyrolee and Patol (n.). The quartz-rocks which prevail near the junction of the Khurna with the Kosila (l.) are largely associated with iron-ore ; and siliceo-ferruginous conglomerates appear at Jliam , Bejapoore , Lolia Bhabur , and Dechowree. Limestone is overlaid by sandstone at a iy. CONTENTS. Bhamouree. Beds of pebbles and gravel occur, far above the r£'i\ of neighbouring streams near Dwarra Hath and Nehal-bridge>* In similar, though in thicker, deposits on the low grounds, many small rivers disappear; after considerable courses beneath the detritus , however, they reappear at the surface. Siliceous sand and granitic gravel are slightly mixed with gold in the beds of the Eamgunga, the Aluknunda, and the Pindur. The operations of native miners in the Himalaya are in the last degree rude, in- effiective, and costly; fire is applied to the rocks to aid the oper¬ ations of the workmen, and torches of resinous wood are used to light them at their labours. Attempts to introduce systematic mining have been made by the Government, but without success. The furnaces, bellows, and other appliances of the native iron- smelters are, beyond measure, rude and inefficient; moreover their charcoal—made of the softest wood—is inadequate to pro¬ ducing the requisite heat. Both the produce and the refuse of the furnaces are divided in recognised proportions amongst the Farmer of the revenue, the Miner, the Smelter, and the Charcoal- burner. The Government revenue from the mines has varied from about three hundred and sixty to five hundred Pounds a year. Many of the inhabitants migrate as the seasons change; and thus those who cultivate the plains at one period of the year, work mines and smelt ores in the hills at another. 1—63. Bengal. The gneiss of the Rajmahal is succeeded by quartz rocks at Fitcooree (a.), and these by siliceous sandstone containing car¬ bonaceous matter and nodules of iron-ore at Jherria. Masses of conglomerate and of amygdaloidal trap overlie the sandstone and a seam of coal croj3S out in the same neighbourhood. Iron-ore oc¬ curs both in nodules and in the joints of sandstones near Taldanga; and on the opposite side of the Barrukkar thin layers of similar ores interlie a body of shale ( b .), At Akysa and Barrul Cajoor rocks and ores of much the same characters are overlaid by a bed of coal, which has been opened in several places (c, d, e.). Both at Jherria and Barrul Cajoor heaps of slag show that iron-ore was formerly smelted in the neighbourhood. 64—8. CHILI. Ciianarcillo. The isolated mountain of Chanarcillo which rises nearly four thousand feet above the Pacific and more than two CONTENTS. V. thousand higher than the surrounding country, consists of three calcareous ( a , c, e.), alternating with two felspathic, quartzose, and hornblendic (£>, d.), strata. They all decline towards the south¬ west, but at somewhat different angles ; and in various parts of the district they differ materially in thickness. Several beds in each of the strata are characterized by diversities of colour, com¬ position, and structure. All five formations are traversed—but without displacement—by two narrow dykes of felspar, horn¬ blende, and quartz. The entire series is intersected by many lodes and branches , of which the greater number bear 18°-45° E. of N.—W. of S., others, however, range nearly at right-angles to them ; but all, without exception, dip oppositely to the strata. The earthy ingredients of the lodes are much the same as those of immediately adjoining portions of the rocks; and their metallic contents undergo a corresponding change as they pass from one formation to another. Native silver abounds not only in many calcareous parts of most lodes , but, for considerable distances beyond their walls , it is disseminated through (the Manto de Ossa ) certain upper layers of the first limestone, and fills, or faces, their joints. Several of the ores of silver are disposed in much the same manner, yet, perhaps, scarcely to the same extent. But notwithstanding the lodes contain silver and several of its ores in the three limestones, their riches and the various ores they afford are by no means equally determined to every part of each stratum. Both the metallic minerals and the vein-stones, however, maintain the same endlong (shoot) dip in every lode and in all the lime¬ stones ; moreover the richest parts of different lodes often occur on the same meridians, in the first limestone, portions of the Candelaria lode afforded virgin metal and ore of various kinds which yielded nine hundred ( Troy) lbs. of silver per (Avoir.) ton ; and in the second limestone sixteen hundred tons of ore from the Colorado lode gave sixty-four thousand lbs. of metal, one-eighth of which was extracted by two miners in a month, A part of Waring's lode was so intertwined with native silver that—too tough for extraction with ordinary tools, and too porous to be blasted—it was cut out, bit by bit, with chisels. In 1855-6 the various ores of Colorado yielded—by smelting—from 0*00279 to 0*00367 and by amalgamation from 0 01172 to 0*01426 their weight of silver, a proportion much smaller than that of earlier years. In little more than a quarter of a century the produce of Chanarcillo amounted to more than six millions Sterling. Between VI. CONTENTS. the several calcareous strata (a, c, e.) the lodes —maintaining their normal directions anddips—partake the felspathic, quartzose, and hornblendic characters of the strata (b , d ) which intervene, hut they then afford traces of blende and small quantities of iron- pyrites only. Several unproductive (cross-) veins, which traverse the district, differ materially from most, yet nearly coincide with some, of the lodes in direction, and—like the lodes in general— they dip oppositely to the strata, but in some measure conform to the endlong (shoot) dip of the ore ; their ingredients — calcareous in some, but felspathic, quartzose, and hornblendic in other, places —closely resemble those of the immediately contiguous rocks ; and they are divided lengthwise by numerous joints, of which the opposite faces are often deeply scored with unconformable striae. On passing from the cellular limestone of the Manto de Ossa into the compact rock beneath, the lodes —diverging from their normal dip and inclining at a much lower angle—take their way for some distance between the two, but ultimately they resume their ordinary inclination. The several interferences of lodes are —even in the same neighbourhood—attended by inosculations, by simple intersections, and by (heaves) displacements. Hitherto the Colorada is the only lode ascertained to cut a cross-vein; and this through an inconsiderable vertical range. In all their inter¬ ferences with cross-veins , however, the lodes are ( heaved) dis¬ placed, longer or shorter distances, towards the left-hand , and to the side of the greater angle (L —G. A.). Neither of the lodes , and one only of the cross-veins , interferes with the levels of the rocks in its opposite sides (ivalls). In the exceptional case, of the flucan at San Francisco viejo, the several strata which form its upper ( hanging-wall) side are many fathoms below their respec¬ tive counterparts in the lower (foot-wall) ; the lodes suffering, at the same time, corresponding displacements. Evidence yet exists that the surface of Chanarcillo was once watered ; and that through the valley of Copiapo a river formerly flowed to the ocean ; now, however, a perpetual drought prevails at the former ; and—even when snow melts on the Cordillera—pools only appear at intervals in lower parts of the latter. This disappearance of water has been concurrent with the destruction of forests in the neighbourhood. The absence of water in the mines is as remarkable as it is at the surface of Chanarcillo; for mines have been opened to, and wrought at, a depth of more than two hundred and sixty fathoms without the aid of pumping-machinery, or, in fact, without the CONTENTS. Vll. appearance of water. But if this absolute drought be beneficial in some, it is at least as prejudicial in other, respects; as it de¬ prives the miner of cheap means for extracting his ores and separating them from the vein-stones. The ignorance and preju¬ dice of the native mine-owner prohibits use of the Avheel-barrow, the windlass, and the ( kibble ) bucket, all ore and rubbish are taken within the reach of horse-power, or to the surface, on the backs of labourers. Owing to these exceptional circumstances, and to the enormous cost of food and drink, much ore, which might have been wrought to advantage, now remains unbroken in the mine, and undressed at the surface. All necessaries of life, both for the people and for the animals they employ, are brought, on beasts of burthen, from considerable distances; of the water, indeed, small quantities only are drinkable ; the rest — like that in the river of Copiapo—containing salts of soda in large proportions. The only Avater used in locomotive boilers on the Copiapo railway is, in fact, obtained by distillation of sea-Avater at Caldera and of river-water at Piedra Colgada; any surplus being sold for household purposes In course of thirty-four years more than tAVO million (Troy) lbs. of silver Avere obtained in this de¬ partment of the Chilian Republic. 69—153. Copiapo. At Quebrada Seca foliated rocks of hornblende, quartz, calcareous-spar, and felspar, more or less mixed Avith several other minerals, are frequently interlaid, although they are sometimes also intersected, by bodies of quartzose, calcareous, and felspathic A r ein-stone unequally charged with earthy broAvn iron-ore, as well as Avith native copper and various varieties of copper-ore in smaller proportions. Trifling quantities of w r ater, in the deepest works are rich in salts of soda. At San Jose rocks of much the same character as those of Quebrada Seca are traversed by tAvo series of joints at the interferences of Avhich masses of quartzose, fel¬ spathic, and hornblendic vein-stones are largely impregnated with earthy brown iron-ore and thinly sprinkled with various ores of copper. Nearly horizontal beds of recent sandstone— pierced at intervals by hornblendic crags — extend from the neighbourhood of Baranquilla to the \ r alley of Copiapo. Great numbers of irregular joints traverse the rock in every part of its range; and on either side of these it rises slightly above the general level. At some three hundred feet above the sea, certain beds of this sandstone contain quantities of ill-preserA r ed Vlll. CONTENTS. and broken shells. At an elevation of, perhaps, one hundred and eighty feet, a railway-cutting near Caldera lays open successive layers consisting either of gravel, shingle, and fragments of rock bored by marine animals, or of shells of existing species in such abundance that they are exported for the sake of the lime con¬ tained in them. Notwithstanding the surface of San Josb is covered with sand impregnated with the salts of soda a shaft of five fathoms in depth affords copious streams of fresh water. At el Bramador near Copiapo loud noises are sometimes heard when large quantities of sand are drifting before heavy gales. During the writer’s sojourn in Chili, more than three days seldom passed without an earthquake. 154—167. BRAZIL. Minas Geraes. The richest part of this productive Province,— situate between Congonhas do Campo on the south, Candonga on the north, tributaries of the River Doce on the east, and the Rio das Velhas on the west,—is about one hundred miles in length and from fifty to seventy in width. That portion of it which consists of undulating table-land and rounded hills, some two or three thousand feet above the sea, is covered with coarse grass (Capim gordura) ; the rest, which rises into serrated ridges and isolated peaks five or six thousand feet high, is, in many places, still clothed with virgin forests. The auriferous series is made up of granite and gneiss, overlaid by micaceous and talcose slates, which are sometimes interlaid by quartz-rocks mixed with mica and talc. The micaceous and talcose slates are succeeded by clay- slate, which passes, at times, into chlorite slate, and often includes large masses of quartz. The clay-slate is followed, sometimes by an inconsiderable deposit of granular quartz and calcareous matter, but far more frequently by thin bands of specular and oxydulated iron, which commonly alternate with granular quartz (Itabirite), and are, at intervals, mixed with the ores of manga¬ nese, as well as with talc and mica (Jacotinga). In some cases, however, the clay-slate is not easily identified ; and, at times, the (Itabirite and Jacotinga) ferruginous, quartzose, and manganesic rocks are imbedded in the micaceo-talcose slates. Hornblendic rocks and siliceo-magnesian limestone occur amongst upper, schist¬ ose, parts of the system. The granite of Candonga contains gold alloyed with palladium ; but that of the Cara£a and of Caeth£ CONTENTS. IX is barren. The quartzose talco-micaceous slate is often interlaid, —and occasionally intersected—by bodies of quartz ; these—at Santa Rita (a.), Rossa Grande ( b .), Cstta Branca {c.), Paciencia ( d .), and Coelho (e .), are of widely different dimensions, and contain unequal proportions of gold, beside smaller quantities of iron-pyrites and the ores of antimony, bismuth, and tellurium, Quartz-rocks of granular structure are, at Catta Preta (/). traversed by vein-like masses of crystalline quartz, which mostly conform to two series of joints, but frequently ramify, and some¬ times enclose (horses) bodies of granular quartz. The crystalline portions are traversed in all directions by short joints, which are often lined with earthy red iron-ore sprinkled with granules of gold. The clay-slate contains many auriferous beds; which— conforming to its cleavage— consist at Tijuco (a.) of spheroidal and angular bodies of brownish quartz, and at Ouro Fino (c.) of globular masses of iron-pyrites and of slate, enveloped in quartzose slate and colourless quartz. At Gongo Soco (Camara) short interlying beds of quartz and earthy brown iron-ore either dwindle and disappear in the rock, or terminate at its joints ( b .). At Morro Velho {cl.') the metalliferous deposit—coinciding some¬ times with the cleavage, frequently with the joints of the rocks, but often oblique to both—assumes the character of a bed in some, but of a lode in other, places ; both its course and its dimensions are therefore irregular; it consists in great measure of quartz, mixed, however, with great quantities of iron-pyrites, and with arsenical pyrites, yellow copper-ore, and other minerals in smaller proportions ; these ingredients embed considerable quantities of slate, mostly microscopic, but occasionally in bodies of large size ; their structure is generally, but not always, coinci¬ dent with that of the neighbouring (Country) rock, which also they commonly resemble in composition ; yet many of them are mixed and transfused with siliceous and pyritic matter ; a thin, highly-inclined slice of slate (tongue of killas) separates the principal formation from the North branch ; a somewhat similar one beneath it, in both the {shoot) endlong dip of the several ores coincide with flexures of the adjoining strata; between the slate (Country) and the vein-stone there is not uncommonly a gradual transition; but beds, and even laminse of the former sometimes protrude from the sides ( walls ), and either partially, or entirely, sever the latter; all these vein-stones—as well as the J 9 7 X. CONTENTS. rocks which bound them—are more or less auriferous, but the pyritic portions are by far the richest ; even in them, however, an admixture of other minerals would seem necessary to their productiveness ; moreover, at various depths vein-stones of differ¬ ent hardness, afford gold, in unequal proportions and dissimilarly alloyed ; silver, however, is always the principal alloy. Length¬ ened experience dictated improved modes of treating the ores; even from 1855 to 1861 the proportion of gold extracted increased from one-half to two-thirds of the actual (assayed) contents , and at the same time the cost of extraction was more than proportion¬ ally diminished. From 1834 to 1862 the produce of Morro Velho realized £2,229,487 and afforded a Net Profit of £661,737. At Ouro Preto (Villa Rica) particles of gold are thinly sprinkled through homogeneous, soft, blue, clay-slate. Quartzose micaceo- talcose slate, which affords mere traces of gold, succeeds the clay- slate at Ouro Preto and Gongo Soco. A thin bed of calcareo- siliceous matter, flecked with micaceous iron-ore and with talc, contains small quantities of gold at Cocaes (pi.) and Gongo ^ Soco (r 2.). The Itabirite (iron-mica slate) and Jacotinga con¬ form to the micaceo-talcose slate which they overlie, and maintain —at the same time—a certain coincidence with the contour of the surface ; the selfsame beds, therefore, take different directions and dips in various parts of their range,—at Antonio Pereira (a.), Santa Anna and Itabira (5, c, d, e.), Monlevade (/•), Boa Vista, Pitangui, Morro das Almas, Agoa Quente, Piracatu Pissarad , Fazendad, Durao , and south of the Per^icaba (g, h, i,j, k, l , mi), the Corrego de Sad Miguel (o.), Cocaes , the Venda do Morro, and Gongo Soco ( p, q, r.). The Itabirite consists in great measure of granular quartz and sundry iron-ores ; these—with smaller quantities of other substances — frequently occur, either mixed or in alternate beds, but—especially in central parts of the formation —granular, scaly, or crystalline iron-glance prevails; schistose structure is usually more pronounced amongst the alternations of iron-ore and quartz than where the ingredients are more exclu¬ sively ferruginous, but even in these it exercises a marked in¬ fluence on the productive character of the neighbourhood. The Jacotinga —partaking the nature of the adjoining (Itabirite) rocks—consists in great measure of iron-glance, earthy black and brown iron-ore, manganese, and talc ; and—somewhat resembling them in structure—is slightly lamellar. The principal members CONTENTS. XI. of the series, however, are certain conformable beds which open at intervals to width of some inches and for several feet, or even fathoms, in length and depth; of these enlargements the central portions contain rough nuggets , flakes, and granules, sometimes isolated, but often united by intertwining threads of gold ; to¬ wards the edges and sides of the bunches grains and particles become more and more thinly sprinkled and the vein-stones at length merge in the ordinary Jacotinga; sometimes several such short, productive beds occur on identical parallels in the same formation; in all cases, however, the richest portions are the most highly inclined; the productive and the barren (Shoots) bodies of vein-stone coincide in position both with the—oppositely undu¬ lated or rippled —planes of cleavage in confronting portions of the (hanging and foot walls) upper and lower sides (c, cZ, f, g , h , i, j, l , o f Pf q. ), and with the several— kindly and uncongenial—strata where they interlie the joints (h. r.) } of the (Country) Itabirite , and at the same time, they all dip (endlong) from the nearest bodies of granite. At Gongo Soco a (horse) mass of Itabirite is both embedded in and penetrate by veins of auriferous Jacotinga. The gold of this formation is alloyed with silver at Agoa Quente , —with copper at Durad ,—with palladium at Santa Anna and liabira; all these substances, however, are alloyed with the gold of Gongo Soco which is associated with less silver, but with more palladium and copper, in deep than in shallow parts of the mine, and contains platina near the surface only. Short, thin cross¬ veins of quartz slightly displace some of the beds, but they soon merge in quartzose portions of the Itabirite. A broad band con¬ sisting of micaceous iron embedding crystals of oxydulated ore in some (m.), but of (Carvoeira) siliceous sand, earthy talc, manganese, and earthy brown iron-ore enclosing isolated masses of quartz in other ( n.), parts of its range, has afforded gold at Catta Preta. The Canga — a breccia in certain, but a con¬ glomerate in different, places, consists, in great measure, of various iron-ores, now and then including fragments of quartz and of slate (d,l,p,r.)‘ at intervals it contains crystalline granules of gold (d, Z.), and in one spot, at least, it yielded auriferous native copper (Z.). Iron-ores from the Itabirite and Jacotinga are largely smelt¬ ed in many parts of the district (a, e, f, Z, o, q , r.). Joints in the Itabirite of Gongo Soco emitted a sufficiency of pure air for the ventilation of a long drift (r-3, 1.). The slaves of the Imperial b _ XU. CONTENTS. Brazilian Mining Association were well-treated, -clothed, and -fed; rewards were given for nicely-kept gardens, clean houses, and general good conduct, a savings-bank was established for them, and their children were taught to read and write. The duration and nature of their labour differed little from the periods and kinds common to young persons in the mines of Cornwall and Devon. The gold extracted by the Association at Gongo Soco realized £1,427,074, the working expenses amounted to £884,937, and the Government of Brazil exacted <£333,180 as Provincial and Export Duty. The Itabirite is succeeded by talcose rocks, mostly of schistose structure, which enclose—bodies of siliceo- magnesian limestone,—short, thin, and generally-conformable, beds of—more or less granular—quartz largely charged with earthy brown iron-ore,—and broad bands of felspathic matter. The barren limestone of Gongo Soco (a.) is burnt for use, but at Antonio Pereira (/*.) the rock is too siliceous for the lime- burner and too slightly auriferous for the miner. The beds of ferruginous quartz at Descoberta (5.), Cattas Altas (c.), Fraga ( d .), Thesoureiro (), and at the Narrows («.), between the Middle landing and Portage brook (&.) on the Big river. Copper-pyrites has been observed at ( d .) and below ( e .) the falls of the Tattagouche as well as at Daly’s (c.) towards the east, near Clarke’s camp and at Armstrong’s brook (/.), and at the Grand fall of the Big river (ft.). Crystals of copper-glance are thinly sprinkled at the fall of the Tattagouche ( d .). Galena accompanies calcareous-spar at Armstrong’s brook (/.). The oxide of manganese is scattered through masses and veins of quartz at the Tattagouche fall ( d .). Crinoidea have been dis¬ covered in the same locality ( d.). A conglomerate (III.) of quartzose and slaty pebbles rests, in nearly horizontal beds, on the granite from the Red brook up the Big river (c.), and a similar rock which overlies the slate at the Long meadow (II. b.) is suc¬ ceeded by siliceous sandstone ( b .). At Blackstock’s mill on the Tattagouche a conglomerate of Slate and quartz rests uncon- formably on schistose rocks ( a Near the road from Bathurst to Miramichi the left bank of the Big river consists of siliceo- micaceous sandstone, quartzose conglomerate, and argillaceous shale ( d , 6,/.) ; but on opposite sides of a joint, in one locality, the strata are differently disposed. The remains of plants, and lignite interlaid and veined with vitreous copper, abound in the shale; which contains also nodules of copper-pyrites and of vitreous copper, sometimes separately aggregated, but more fre¬ quently an envelope of one ore surrounds a kernel of the other. Both the lignite and the masses of ore are encrusted with the carbonates of copper. At Parrot’s brook, east of Bathurst, an erect fossil trunk rooted in shale is encompassed with ferruginous sandstone alternating with carbonaceous shales rich in vegetable remains (/.). 490—510. JAMAICA. In a low hill of hornblendic granite on the eastern confines of Saint Thomas in the Yale, a portion of the rock, which in direction coincides with the joints of one series, and preserves a XV111. CONTENTS. general width of four or five fathoms, is unequally sprinkled with small rough spheroids and other shapeless masses of copper- pyrites, earthy black copper-ore, specular iron, and earthy brown iron-ore, frequently invested with malachite; for the most part they are isolated, but in some cases microscopic threads of copper- pyrites unite them (a.). A similar (? the same) body of horn- blendic granite, charged in like manner with ore of copper and iron, is traced for some distance in the adjoining greenstone (&.). 511—512. SPAIN. At Huidobro in Old Castile concretions of the blue carbonate of copper occur at irregular distances in a stratum of buff-coloured siliceous sandstone ("«.); which is separated by a barren bed of tenaceous clay (&.) from a great thickness of quartzose sandstone (c). Of this body the productive part may average twenty-five, but it seldom exceeds forty, feet in thickness. Earthy brown iron-ore is sometimes abundant, crystals of the sulphate of barytes are grouped in some of the beds, and lignite abounds in some of the lower layers ; isolated bodies of iron-pyrites, copper- pyrites, earthy black copper-ore, and vitreous copper are not uncommon, whilst the blue carbonate of copper is a frequent constituent and malachite is yet more plentiful. Near several horizontal joints the sandstone, is both more ferruginous and more richly charged with copper-ore than elsewhere. Some of the mines have afforded notable quantities of petroleum (e.) In great part of the neighbouring district greyish-white limestones overlie the sandstone ( d .). At Eardiston in Shropshire the New Red Sandstones consist in great measure of granular quartz, mixed, at intervals, with ferruginous clay. A portion of the mass, which varies from a few inches to several feet in width, —and is sometimes bounded by (smooth walls) joints, but occasionally shades into the adjoining (Country) rock,—contains much earthy brown iron-ore in some, and is, more or less, charged with the green carbonate of copper in other, parts of its range; grains of grey copper now and then present them¬ selves, and thin incrustations of malachite line many of the (vughs) cavities. The cupriferous deposit is intersected, but without displacement, by a cross¬ vein of clay. 513—516. FRANCE. The ancient mine of Chalanches , near Bourg d’Oisans, is wrought in granitic gneiss, on several widely divergent lodes, of com para- CONTEXTS. XIX. tively low inclination ; their ingredients resemble, in some measure, although they are not identical with, those of the adjoining rocks, and are mixed with many metallic minerals; amongst which native silver, and the ores of silver, of cobalt, of nickel, of copper, and of iron occur most frequently. A cross-vein which differs from the lodes less than some differ from others of them in direction, but is of higher inclination than theirs—intersects and (heaves) displaces one of the lodes. The works were carried on at elevations so great that, during great part of the winter, people lodged at the mine were debarred all intercourse with their nearest neighbours. 517—529. THE CHANNEL ISLANDS. Sark. The metalliferous rocks of Sark consist in great measure of felspar and hornblende ; mixed, however, with smaller quantities of several other substances. Several lodes have been laid open, but one of them only ( b . 1 —4 a.) —at Sark's Hope mine, in Little Sark, the south-western part of the island,—has proved productive. From this considerable quantities of several silver- ores were obtained ; sometimes separately aggregated; but, j>er- liaps, more frequently associated with various compounds both of lead and of copper. From the surface to sea-level the ores were principally the salts of these metals, but at greater depths their sulphurets prevailed. The masses (shoots) of ore—conforming in some degree to the structure of the adjoining rocks—dip endlong towards the south-south-west; and in that direction they have been pursued for some distance beneath the sea. 530—539. IEELAND. Wicklow. The homogeneous dark-blue and variegated clay-slates which prevail in the south-west, but graduate into massive siliceo- felspathic rocks in the north-east, of the district of Ovoca, are interlaid by (the Sulphur-course) a metalliferous band which from Connorree in one, to Ballymurtagh in the opposite, direction, has been wrought for a width of from six to more than seventy feet. Throughout its entire range the shallower parts consist chiefly of earthy brown iron-ore, sprinkled with iron-pyrites, various ores of copper, and of several other metals. At greater depths iron-pyrites becomes the princijml ingredient; but, at c XX. CONTEXTS. intervals, it includes bodies of yellow copper-ore ; quartz, al¬ though less abundant than in most other metalliferous deposits, is often a large constituent; and slate—from mere microscopic specks to (horses) masses of several fathoms in length and depth,— abounds in almost every part. Auriferous silver has been found imbedded in earthy brown iron-ore at Cronebane, and thinly scattered, in a state of extreme subdivision, amongst the sulphur- ore of Connorree. Gold occurs in both the earthy brown iron-ore and the pyrites of Ballymurtagh , but in proportions far too minute to repay the cost of extraction. A striking peculiarity of the formation is that the iron-pyrites, the copper-pyrites, and the slices of slate which interlie them, all display,—as well in direction and dip as in degree—the selfsame schistose structure as the ad¬ joining (Country) slate ; differences between the ( Country) rocks and the vein-stones, however, are more distinctly marked where they are bounded by (joints and planes of cleavage) lines of structure than elsewhere. North-west of the principal metal¬ liferous bed, but west of the Ovoca, a second, similar, broad band of ore has been largely wrought at Ballymurtagh. On either side, yet within short distances, of the Great Sulphur-course , parallel beds of similar character, but of smaller dimensions, appear and vanish at intervals ; some of these—as well as of numerous small veins which accompany cross-joints in the rock—contain, especial¬ ly towards the south, however, larger proportions of copper-ore than most other parts of the formation. One of these (the South- branch in Connorree), although of much the same composition as the rest, maintains—like the Main lode at Bearhaven —a lower inclination than they or than the cleavage-planes of the contiguous slates. Of three cross-veins , which intersect the Great Sulphur- course in Cronebane and Tigrony , two (heave) displace it in oppo¬ site directions, but the effect of the third is yet unknown. Three cross-joints traverse it at Ballygahan, and all heave it the same way, but to unequal distances at different depths; at Connorree, however, similar joints occasion no displacement. From 1840 to 1866 the exports from this district amounted to 105,432 tons of copper-ore, and 1,960,119 tons of (sulphur-ore) iron-pyrites, besides large quantities of hematite and earthy brown iron-ore. The mine-water is everywhere more or less impregnated with metallic salts; in one mine, indeed, to such an extent that the pumps were protected from it by wooden linings, and the (plungers) CONTENTS. XXI. forcers were also of wood. The precipitation of copper from such water, by the immersion of iron, was introduced at Cronebane , about one hundred and fifty years ago, by a Cornishman, who had become acquainted with the process in his native county ; and from that time to the present it has been carried on, in various parts of the neighbourhood. The precipitate is greatest in autumn and early winter; but it is deposited more rapidly in warm than in _ cold weather, and from running than from still water. The Parys and Mona mines have been uninterruptedly wrought, in the clay- slate of Anglesea, on masses, beds, and strings of quartz, quartzose-slate, iron- pyrites, and yellow copper-ore, from the discovery of copper-turf at the surface in 1768, until now. The principal works—which are open to the day'—com¬ prehend an area exceeding seventeen acres and a half, and extend from eighteen to twenty-three fathoms below the surface ; whilst separate metalliferous beds in the immediate vicinity are wrought to much greater depths. The richer ore was prepared in the usual manner ; but the poorer was burnt, as at Agordo. By burning, most of the ore in each lump was determined towards the centre, although some yet remained in the outer part. Water from the mine—al¬ ready rich in the salts of copper was pumped on this refuse burnt ore ; and, having percolated through it, was conducted into shallow reservoirs thickly spread with scraps of iron. Of late years, however, the burning has been discontinued and the water passes directly from the mine to t\\e precipitation- pits. From 1862 to 1866, there were consumed at the Parys mine 2,746 tons of iron, and the 1,546 tons of precipitate obtained contained about 108 tons of fine copper. From 1832 to 1866 the consumption of iron at the Mona mine amounted to 30,386 tons, the precipitate weighed 30,735, and the fine copper 2,977 tons. The results obtained at Chacexcater suggested the operations which have since been conducted in other parts of Cornwall, in Ireland, on the Continent, and in the West Indies; but it was not until 1854 that the mineral contents of the enormous stream of mine-water which, for more than a century, had issued from the Great Gwennap Adit was submitted to experiment ; subse¬ quently, however, precipitation-works have been established from the point of its exit to the sea. 540—592. Waterford. The mine of Knockmahon is, for the most part, wrought in variously-coloured, yet generally homogeneous, slates; but, in some of the works, massive rocks have been observed. The lodes bear 30°-45° W. of N.—E. of S., and consist, in great measure, of quartz, quartzose slate, slate, slaty and felspathic clay, chlorite, and calcareous matter; near the surface they contain also small quantities of earthy brown iron-ore, at greater depths iron-pyrites and several varieties of copper-ore obtain, and the xxu. CONTENTS. deepest works have been rich in copper-pyrites; differences of composition, however, often characterize subordinate veins, into which the lodes are sometimes divided by longitudinal joints. The lodes bear obliquely to the trend of the cliff, and incline unconformably to the cleavage of the slate; but the (Shoots) bodies of ore and of vein-stone they contain—adapting them¬ selves to the several beds which adjoin them—pass endlong, be¬ neath the sea, and have been largely worked there. Some of the workmen have pursued their shallower works so incautiously, that the sea has, more than once, found its way into the mine. Cross (flucan) -veins —which course 20°—45° E. of N.—W. of S., but have opposite dips—intersect and—save in one instance—displace (heave) the lodes; always, however, towards the right-hand and to the side of the greater-angle (R.—G. A.). In the single ex¬ ceptional case one branch of a cross-vein simply intersects, whilst other branches of the same vein displace, the lode. From 1825 to 1865 the produce of the mine realized £1,399,232, and the Shareholders received a net profit of £489,153. 593—601. Cork. At the Bearhaven , or Allihies, Mountain-mine the rocks consist mostly of siliceous and chloritic or talcose matter, unequally sprinkled with the carbonate of lime, and minutely veined with quartz ; adjoining, and within short distances of, the lodes they assume pale-buff, or lilac hues, and a thick-lamellar structure prevails ; elsewhere they are blue and fissile. Three series of joints are common alike to the rocks and lodes. The Main lode and the planes of cleavage in the adjoining slates have much the same strike ; but—exhibiting almost a solitary exception—its dip is at a lower angle than theirs. The Mountain lode is—as well in direction as in underlie—oblique to both. From the surface to one hundred and forty fathoms deep the Mountain lode comports itself as a branch from one side of the Main lode; but at greater depths the north (side) wall of the latter preserves its continuity and severs the former; the identical body of rock intersected by the lode in one spot, thus intersecting the selfsame lode in another. The lodes are seldom equally productive at the same depths; yet in both the most highly inclined parts are usually the richest. Their principal ingredient is hard, massive, quartz, tinged with the salts of copper in some, but with earthy brown iron-ore in other, places; chloritic or talcose matter is not uncommon, and isolated CONTENTS. XX111. masses of calcareous-spar and of the carbonate of iron present themselves here and there; numberless angular bodies (horses) of slate—varying in size from a fraction of an inch to some fathoms in length, depth, and thickness, resembling the adjacent rocks in composition and generally coinciding with them in cleavage—are enveloped in the other vein-stones. Iron-pyrites, vitreous copper, and some other metallic substances occur at inter¬ vals, but yellow copper-ore prevails. A cross-vein intersects, but does not (heave) displace the main lode. Notwithstanding the works have been opened to considerable depths, in schistose rocks, at less than a mile from the sea, the streams which enter them merely suffice for use at the surface. During thirty years past all ore and rubbish have been drawn out of the mine on a. railway worked by a small high-pressure steam-engine placed at the adit. Forges for the repair of tools have long been established at various depths, and of late a Man-engine has been set up. 602—610. Kerry. The mine of Ardtully was worked on a metalliferous deposit which—for great part of its course—is bounded by (? Carboniferous) slate on one side and by thin-bedded Carboniferous limestone on the other ; in one part of its range, however, slate occurs on both sides. But whether traversing the slate, or con¬ tained within it in one and limestone in the opposite wall , the earthy ingredients of the lode partake, to some extent, the nature of the adjoining rocks; whilst the ores of copper scattered through the vein-stones are, at the same time, characteristically different. A nearly parallel metalliferous repository (the Forge lode) — wholly contained in the limestone — consists chiefly of greyish limestone and calcareous-spar, but sometimes one, sometimes the other, prevails. To a depth of twelve fathoms purple copper-ore abounded; and vitreous copper, copper-pyrites, and earthy black copper-ore occurred in notable quantities; thence, downward, however, the ores rapidly declined, and at length they appeared only in granules and thin strings sparingly distributed through the vein-stones. A second coincident band of calcareous matter, on the same meridian, afforded lead-ore only ; but whether this is, or is not, the equivalent of the formation wrought at Shana- garry , towards the west, has not been ascertained. A cross-vein intersects both the slate and the limestone, as well as the Ardtully lode where it interlies them, but it occasions no (heave) displace¬ ment of either. 611—622. XXIV. CONTENTS. Meath. At Brownstown beds of crystalline, blackish-blue Car¬ boniferous limestone alternate with thin layers of calcareo-siliceous shale ; the former at intervals, the latter everywhere, charged with organic remains. The limestone contains two bands which —partaking the nature of the adjoining rock (Country )—consist in great measure of calcareous-spar, mixed and frequently veined, however, with granular, massive, and crystalline quartz. Angular bodies of limestone are imbedded indifferently in the siliceous and the calcareous ingredients, and sometimes partly in either. Near the surface earthy brown iron-ore is scattered through friable portions of both the calcareous-spar and the quartz ; and these are often interspersed with malachite and earthy black copper-ore. At greater depths the matrix is, at intervals, sprinkled and striped with copper-pyrites, which is frequently invested, and the crevices and joints are often faced, with earthy black copper-ore; but in such places malachite is seldom found. In all parts of both re¬ positories the ores of copper prefer the siliceous, to the calcareous, vein-stones. At seventeen fathoms from the surface two joints of a large Encrinite were discovered in a quartzose gangue , and some¬ what deeper a specimen of another organism (? Turbinolia) w r as found imbedded in a subordinate vein of massive copper-pyrites. 623—626. The Detrital Gold of Wicklow. The beds of several small streams, which rise on the north-eastern slope of Croghan Kin- shela, and both east and west of Croghan Moira, consist of gravel, shingle, boulders, and angular blocks of divers slates, frequently mixed with pebbles of granite, and of other earthy substances, as well as with masses of several ferruginous minerals, a trifling amount of tinstone, fragments of other ores, and minute propor¬ tions of gold; all imbedded in, sand and clay, the debris of neighbouring rocks and veins. It appears that gold was discovered at Baffin valley in 1796 ; and that the rush of people to the spot, shortly attracted the attention of Government. Commissioners were immediately appointed to direct systematic operations; and up to 1798—when they w r ere interrupted by popular commotion —their works had been remunerative. In 1801 proceedings were resumed, and openings were also made at Ballycreen and Bally- nacapogue ; but—proving less successful than before—they were shortly abandoned. In 1842, and again in 1857, trials were CONTENTS. XXV. carried on by private Companies, but, on both occasions, they were soon relinquished. During intervals between the operations of Government and of the two Mining Associations, the refuse from their works, and the beds of the streams, were continually gleaned by the peasantry. The detritus is, in general, shallow enough to be conveniently wrought by open-cutting ; but, in one instance, at least, it was worked by means of shafts sunk to the (shelf) unbroken rock, and by (levels) drifts along its surface. The quantities of gold respecting which accounts have been obtained amount to more than one hundred and fifty (Troy) lbs.; and it is believed that much beside was, from time to time, collected and carried off by the people. Some of the nuggets found at first weighed many ounces a piece ; but, even then, most of the gold consisted, and now the whole consists, of scales and granules of very small sizes. Whether the masses are large or small, most of them seem to have suffered great attrition ; yet amongst them—as amongst the detrital gold of most—if not of all, other countries—small well-preserved crystals have been sometimes obtained. Its quality, like that of stream-gold generally—is very good. Attempts were made, both by the Government and by the Carysfort Mining Company, to discover the parent forma¬ tion, but without success; for—until recently amongst the ores of Ballymurtagli —no part of the district had afforded gold in situ. 627—634. GREAT BRITAIN. Merionethshire. At Clogau the Saint David lode is bounded on the south or lower (foot-wall) side by rocks of felspar and chlorite, thinly sprinkled with quartz and calcareous spar; but on the north or upper (hanging-wall) side by homogeneous slates, either enclosing masses, or alternating with beds, of fel- spathic, chloritic, siliceous, and sparry matter. All these are cleaved at high angles, and divided by two series of persistent joints, as well as by others taking different directions and of shorter range. The auriferous repository varies very greatly in width, maintains nearly the same direction as the joints of one series, and—although sometimes inclining towards the north—is, on the whole, nearly perpendicular. Its principal constituents are quartz, calcareous-spar, and—as the adjoining (Country) rock is of one kind or other—either felspathic and chloritic XXVI. CONTENTS. matter, or homogeneous slate; these several ingredients are often separately aggregated, but, possibly, as frequently, mixed. Smaller quantities of pearl-spar, the sulphate of barytes, and other earthy minerals occur at intervals. Near the surface earthy black iron-ore abounds; somewhat deeper, yet in com¬ parative shallow portions of the lode, iron-pyrites and copper- pyrites are common ; but—although peculiar to neither of the vein-stones—they are most plentiful in a quartzose matrix. Granules of blende and galena, and crystalline scales of tetra- dymite are not unfrequent. Both the quartz and the calcareous- spar are sprinkled with particles and grains of gold ; and inter¬ twined with golden threads which unite in small nuggets at their reticulations. The gold may, perhaps, be less plentiful, but it is of coarser grain, in quartzose than in sparry, parts of the deposit. From June 1860 to December 1867 the mine afforded 1,008 (Troy) lbs. of gold, which averaged twenty-two carats fine. 635—642. Perthshire. At Corri Charmaig the quartzose mica-slate which prevails, near the head of Loch Tay, is associated with felspathic and hornblendic rocks, of schistose structure, comprehending a broad metalliferous band, which in different parts of its range contains vein-stones of separately-crystallized felspar and horn¬ blende, variously-coloured serpentine veined with diallage, ste¬ atite, asbestus, and talc—passing into chlorite—thickly sprinkled with garnets. The chromate of iron—as well in crystals and narrow reticulated veins, as in angular and rude spheroidal masses,—occurs in several parts of the repository ; but mostly invested with talcose matter, and always in a vein-stone of ser¬ pentine. The formation is intersected by two series of veins; but numberless others, of short range, are peculiar to the serpentine; and it may be noteworthy that the (bunches) masses of ore are seldom alike in quality, and frequently their forms are dissimilar, on opposite sides of the joints. From 1855 to 1860 some seventy tons of ore were quarried ; of this some realized five Pounds and two shillings (£5:2:0) per ton, the rest remained unsold. Towards the middle of die last century the neighbouring lead-mine of Tyndrum was wrought to advantage under the superintendence of Mr. Rudolph Erich Raspe, who—when the German system, of levels, winzes, and back-slopes , was substituted for the bottom-stopes which until then prevailed in Cornwall—had been already employed at Dolcoath; where, according to local tradition, he composed a well-known work of fiction. 643—649. CONTENTS. XXY11. At Tomnadashan , south of Loch Tay, the prevailing mica-slate is traversed by a broad band, composed mostly of felspar/horn¬ blende, chlorite, and quartz, which present felspar porphyries in some, but greenstones in other, parts ; the former—often contain¬ ing isolated crystals of felspar—are usually determined to the middle, the latter towards the sides, of the formation ; bodies of either rock, however, enclose masses, and are penetrated by veins, of the other. Two lodes , bearing respectively S.E.—N.W., and 25°—30° S. of E.—N.W., traverse both the greenstone and the porphyry ; their principal vein-stones, whilst in the former, are felspar and hornblende, but in the latter they consist, in great measure, of felspar and quartz. Near the surface earthy brown iron-ore, small bunches of copper-pyrites, and nests of earthy black copper-ore sprinkled with malachite are of common occur¬ rence ; but downward the earthy ore is replaced by pyrites, yellow copper-ore is more plentiful, and granules of fahlerz and of galena are thinly sprinkled through the matrix. As the lodes converge, the rock between them is intersected by numberless intertwining veins of felspathic, hornblendic, quartzose, and chloritic matter, which give the entire mass a brecciated character. The sulphuret of molybdenum has seldom been noticed in the lodes; but— accommodating itself to the striae, which score both the vein-stones and the rocks at their contact, it,—not uncommonly, shows itself as a slickenside. On the margin of the lake, however, it appears in small crystals scattered through the porphyry and facing its joints. 650—654. Cornwall. The Caradon District comprehends — the south-eastern portion of the Bodmin-moor granite,—the slates which skirt it,— the hornblendic rocks associated with the slates,—and the elvans which—although imbedded in granite at intervals,—usually tra¬ verse both granite and slate. But beside the vast sheet of slate which extends, towards the east and north-east, from the granite of this region to the confines of Cornwall, a tract of slate scarcely a mile in length or half-a-mile in width, is bounded on one side by the granitic slope of the Cheesewring and on the other by a body of granite which reaches most of, if not all, the way from Caradon to Knovol. Within this patch of schistose rock, how¬ ever, the S., upper side (hanging-wall) of the Phoenix lode to about thirty-five fathoms from the surface consists of slate ; d XXV111. CONTENTS. whilst the confronting portion of the N., lower (foot-wall) side, and both sides (walls) at all greater depths, are composed wholly of granite. The shallower parts of other lodes in the immediate vicinity seem likewise bounded by slate on their (S.) upper, but by granite on their (N.) lower, sides; but whether these bands of granite may, or may not, traverse the entire width of slate, has never yet been ascertained. At Marke Valley —on the junction of the great slate-formation with the granite—the lode , which dips towards the north, is accompanied on its N. or upper (hang¬ ing-wall) side, to a depth of thirty-six fathoms, by slate; but in the opposite parts of its S. or lower (foot-wall) side, and at greater depths on both sides, by granite. Generally speaking, the granite is composed of felspar, quartz, and mica; the joints by which it is traversed, as well as the bedding which conforms in some measure to the contour of the surface, are conspicuous at the Cheesewring, where the rock is largely quarried for exportation. On the confines of the formation schorl is frequently a constituent; in the vicinity of the lodes chlorite is not uncommon; and in more than one part of the district tin-ore is a large ingredient. The slates consist—as the granite in contact with them also con¬ sists—chiefly of felspar and quartz ; mixed with either mica or chlorite ; and, at some distance from the granite, they are occa¬ sionally interlaid by hornblendic rocks. Several eZmn-courses— bearing 15°—30° N. of E.—S. of W.—intersect, indifferently the granite and slate ; and—apparently unconnected—masses of elvan are, here and there, imbedded in the granite. In the different (Countries) rocks their components are, perhaps, scarcely identi¬ cal ; usually, however, they contain crystals of quartz and of felspar isolated in a basis of quartz and felspar, now and then, sprinkled with mica and schorl. The lodes —comprehending the several minerals of the adjoining rocks—consist, in great measure of quartz, chlorite, and felspar, associated, at intervals, with schorl and mica; sometimes separately aggregated, but more frequently intimately mixed. The joints of one series—well marked in the rocks—take much the same direction as many of the lodes; and — traversing them longitudinally — thus develope subordinate slices , veins , or combs , which, not uncommonly, display charac¬ teristic differences of composition and structure. Both N. and S. of the Caradon range the shallower parts of the lodes often contain earthy brown iron-ore ; but it and the minerals associated with it CONTENTS. XXIX. are not exactly alike on opposite sides of the granite. In the N. portion of the granite, and in the contiguous slate, dark-brown and blackish iron-ores are scattered through hard, massive, cavern¬ ous quartz, and—downward especially—mixed with chlorite ; in this congenial matrix tin-ore is sometimes abundant. Softer, and lighter-coloured, iron-ores and granular quartz are—in the same neighbourhood—impregnated with several ores of copper. On the S., however, the outcrops of the lodes consist of soft, yellowish and reddish-brown iron-ore, granular and friable quartz, chlorite, and fluor, and in these copper and many of its ores often abound. Thus the lodes on one side of the granite afford tin-ore and copper- ore, but no fluor ; whilst those on the other yield fluor and various ores of copper but are destitute of tin-ore; which, nevertheless, is an ingredient of the neighbouring rock. The direction of the lodes —ranging between 5° S. of E.—N. of W. and 35° N. of E. —S. of W. —is, on an average, some 18° N. of E. — S. of W. The bedding of the granite at the Cheesewring and the cleavage- planes of the slate throughout the district decline from the central body of the granitic formation ; the lodes , on the contrary, dip generally towards it. The lodes peculiar to the granite measure about 2*, but those which, wholly or in part, traverse the slate average 6*8, the general mean being about 3*2, feet in width. The cross-courses —partaking in some measure the nature of the rocks they intersect—contain granitic matter when in granite, and elvan when in elvan ; but—differing in this respect from the lodes , which contain larger proportions of quartz—they are usually more felspathic than the (Country) rocks; moreover, there seems an occasional approach to uniformity in the positions of the crystals of felspar they include. Their directions—differ¬ ing little from those of one well-pronounced series of joints — range from 6° E. of N.—W. of S. to 24° W. of N.—E. of S. and average 13° W. of N.—E. of S. ;—more highly inclined than the lodes —they dip just 80° from the horizon, and—in this respect resembling the lodes on both sides—incline towards the great body of granite. In this district—as throughout Cornwall generally— the cross-courses are rather broader than the lodes; they vary from 0*6 foot to 24 feet, and average 4 - 6 feet, in width. Of the lodes intersected by cross-courses , some are (heaved) displaced towards the right-, others towards the left-hand, and in a few instances the intersections are unaccompanied by displacement. XXX. CONTENTS. The mean amount of displacement is greater near the surface than at considerable depths ; and by wide than by narrow cross¬ courses. One of the principal cross-courses, however, is inter¬ sected by a (course) vein of quartz. Copper is precipitated from the drainage of an abandoned mine; and from water used for household purposes in the neighbourhood. Notwithstanding the extent of early tin-mining in the vicinity, and that copper-mines had been long, largely, and profitably wrought, as well on 1 oth sides of the Tamar, as in many parts of Western Cornwall, it was not until 1835—1840 that they were opened with success on the slopes of Ca radon; yet Rail way-waggons were adapted to at least one inclined shaft in this region before they were generally used in other parts of the County. In 1851, 5 water-wheels and 13 steam-engines worked the pumping and stamping machinery, and more than 1,200 people were employed, in the district. In 18G8 East Caradon and the Phoenix mines had already yielded large profits; and at Marke Valley £50,000, — at West Caradon about £110,000, — and at South Caradon £315,605 had been divided amongst the shareholders. 655—698. The Lead-mixes of Menheniot, Lanreath, and Saint Pinnock are opened in schistose rocks of greenish, brown, drab, or dun-colour near the surface, but of dark-blue or blackish hue at greater depths. Nests of pulverulent ferruginous matter (? of organic origin) occur here and there in a shallow quarry between Wheal Trelawny and Wheal Mary Ann, and similar bodies, as well as Crinoideal remains, are obtained on the way-side near Herod's- foot. On one side or other, and occasionally on both sides, of the Menheniot lode, the slate is interlaid by conformable beds and isolated bodies of felspathic and hornblendic rocks; which are, perhaps, connected with some, of several, similar masses contain¬ ing spheroidal concretions of identical composition. The only lode yet wrought at Menheniot takes, on the whole, a nearly meridional range, maintains an average inclination of nearly 80° E., and varies, from six inches to four feet, in width. The lode of (Lanreath and Saint Pinnock) Herod's-foot bears slightly W. of N.—E. of S., preserves also a trifling E. dip, and is from a foot to three feet wide. Of both lodes the chief ingredient is quartz; often granular near the surface, but generally massive and of milk-white hue beneath; angular masses of slate and of quartzose slate, cleaved and jointed uniformly with the adjoining CONTENTS. XXXI. (Country) rocks, are very- numerous, and the crevices between them are not unusually faced with crystals o£ quartz, of calcareous- spar, and of galena; fiuor and the sulphate of barytes abound in portions of the Menheniot lode , and pearl- spar is not uncommon at Herod's-foot. At and near the surface earthy brown iron-ore is plentiful; in many, if not in most, parts iron-pyrites is a fre¬ quent constituent; copper-pyrites and blende are disseminated through quartzose portions of the vein-stones; and ores of anti¬ mony occur in minute proportions. In the Menheniot lode lead- ore is more plentiful near the middle than towards the sides, and it appears more frequently in grains, and isolated masses connected by thin veins, than in large (courses) bodies of endlong (shoot) dip; but the quartzose vein-stone of the Lanreath and Saint Pinnock lode contains numberless small hunches and thick ribs of galena. In both these—as in most, if not in all, other— lodes the lead-ores from different parts are unequally rich in silver. The cross (jlucan)-vein of Herod's-foot differs from the cross (jlucan)- veins of Wheal Trelawny and Wheal Mary Ann —as much as the lodes they respectively intersect differ—in direction ; whilst its width is greater than theirs. Of the cross-veins which intersect the lode at Wheal Trelawny and Wheal Mary Ann one displaces (heaves) it towards the left -the other, generally, towards the right-hand , yet both displace (heave) it to the side of the smaller angle. The cross-vein at Herod's-foot heaves the lode also to¬ wards the right, but to the side of the greater angle. The same cross-vein , however, heaves the lode unequal distances at different depths ; indeed it heaves at one spot, but simply intersects at another. During 1851 the pumping- and stamping-machinery were worked by 3 water-wheels and 10 steam-engines, whilst more than 1,000 people were employed at the mines. Profits, which amounted—at Herod's-foot to £49,848,— at Wheal Tre¬ lawny to £56,914, and at Wheal Mary Ann to £65,585, were from 1844 to 1868 divided amongst the shareholders. Wheal Wrey , a neighbouring mine, continued to yield for some time con¬ siderable quantities of rich silver-ore. G99—720. CORRECTIONS. Page. Line. Page. Line. 3 27 for Nyee read Nynee 224 21 for iron mica-) read iron-mica 6 21 99 Alaknunda 99 Aluknunda slate j slate 14 10 99 Joins 99 Joints 225 18 99 mica 99 talc 20 6 99 Oar 99 Garh. 227 4 99 iron mica- 99 iron-mica 22 5 99 Shealgar 99 Shealgarli slate 99 slate 29 5 99 octohedral 99 octahedral 99 7 99 Mica 99 Talc 35 6 99 Hurcliinoolee ,, Hurchinolee 231 29 99 C-606944 99 0-006944 37 12 99 has general 99 has in general 237 25 99 Interieur 99 Interieur 46 16 99 found 99 collected »> 26 99 am on gat 99 amongst 50 19 99 formed 99 farmed 243 15 99 24* 99 245. n 26 99 persuit 99 pursuit 248 5 99 palish 99 paleish 53 4 99 tables 99 tackles 254 20 99 II. 99 IV. 67 1 99 maasure 99 measure 263 6 99 II. 9 > IV. 69 28 99 XX. 99 IX. 290 31 99 contain 99 contained 70 19 99 even 99 ever 292 44 99 0-146 99 0-145 » last 99 mountain 99 surface of the 343 14 99 Lour 99 La uk mountain. 348 14 99 two shillings 1 71 26 99 9 99 16-5—17 & nine pence j 99 nine pence 81 8 99 88° n 35° 358 17 99 Pereiro 99 Pereira 105 last 99 Patti son 9 9 Pattinson 405 10 99 29° S. of E.) 99 29° E. of S. 121 40 99 0-000096 to > 99 0-000918 to —N. of W.} —W. of N. 0-000384 ) 0-003673 410 82 99 29° S. of E. { 99 29° E. of S. 126 last 99 $ 99 t —N. of W. f —W. of N. 138 37 99 os 99 as 422 9 99 hornblende ) 99 hornblende, 142 6 99 Copiopd 99 Copiapd labradorite) labradorite 146 26 99 1786 99 1788. » 28 99 zoolitic 99 zeolitic 150 23 99 Copiopd 99 Copiapd 435 11 99 of fine copper 99 of copper 154 22 99 Brenador 99 Bramador »> 14 99 of copper 99 of fine copper 157 19 99 1839 99 1859 436 23 99 mosses 99 masses 166 12 99 dupuis 99 depuis 472 12 99 0-0331 99 00031 169 43 99 de 99 da » 29 99 0-3134 99 0-0134 173 15 99 I. 99 L. »» 33 99 Polberrow 99 Polberro 41 99 Peroxide 99 Protoxide >» 37 99 0-3063 99 0-0063 191 11 99 14 99 15 515 1 99 Eardistan 99 Eardiston 193 18 99 folice • 9 folia »* 46 99 XXXIX. 99 CXXXIX. 27 99 Gamba 99 Gamba 533 15 99 jaspar 99 jasper 196 7 99 itself 99 alone 544 3 99 eruptive 99 eruptive 197 28 99 Ibid 99 Capt. Treloar 564 23 99 more highly 99 less 198 33 99 217-321 99 220-210 574 22 99 1868 99 1768 )* 34 99 292-978 99 293-080 586 16 99 1768 99 1748 199 20 99 123-8 99 124-2 »> 19 99 water 99 copper 99 21 99 10-08 99 1-108 598 19 99 lode 99 Jlucan 211 2 99 mica 99 talc 603 27 99 29° 09' 99 28° 05' 99 11 99 mica 99 talcose 612 17 99 southard 99 southward 213 15 99 Braiilien 99 Brasilien 616 3 99 ae mtalliferous 99 a metallifer¬ 99 20 99 Perrira 99 Pereira ous 718 22 99 structure 99 structure Observations on Metalliferous Deposits . By WILLIAM JOEY HENWOOD, F.R.S., F.G S., MEMBER OF THE GEOLOGICAL SOCIETY OF FRANCE; PRESIDENT OF THE ROYAL INSTITUTION OF CORNWALL ; HONORARY MEMBER OF THE YORKSHIRE PHILOSOPHICAL SOCIETY : CORRESPONDING MEMBER OF THE IMPERIAL AGRICULTURAL AND NATURAL HISTORY SOCIETY-LYONS, AND OF THE LYCEUM OF NATURAL HISTORY—NEW YORK ) SOMETIME HER MAJESTY’S ASSAY-MASTER OF TIN IN THE DUCHY OF CORNWALL ; MEMBER OF THE SOCIETY. The object of this Memoir is,—to describe deposits of iron, copper, lead, chrome, cobalt, nickel, silver, and gold, associated with rocks of different ages, in various parts of the East and West Indies, North and South America, and the Continent of Europe;—to compare them with such as yield both similar and different ores —especially the ores of copper, lead, and tin—amongst formations of less varied composition in the West of England ; *—and to trace the local peculiarities, which —in subordinance to general laws—have determined their distribution. The rocks of Kumaon and Gurhwal, two North-western Provinces of India, are granite; gneiss; micaceous, talcose, chlorilic, hornblendic, and clay slates; limestone ; and sandstone. * Cornwall Geol. Trans., v. pp. 1—386. o \V. J. Henwood, on the Metalliferous The iron and copper ores, which have from time immemorial been wrought by the natives, are for the most part in the slate, especially in the clay-slate formation ; but copper has also been obtained amongst the calcareous rocks; and although hitherto in small quantities, iron-ore has been found in the sandstone of the Sub-Himalayan range. Three* small patches of granite occur,—near Dwarra Hath, at Almora, and at Deo Dhoora,—within the metalliferous district; but no ore of any kind has hitherto been found in either of them. In texture the rock somewhat resembles the granite of Cornwall, and is rather coarse-grained; but it is sometimes traversed by veins of a variety more minutely crystalline. Its ingredients are for the most part felspar, quartz, and mica; but near Dwarra Hath the latter is here and there replaced by talc, and schorl occasionally appears; whilst hornblende abounds towards the confines of the formation near Deo Dhoora; and porphyritic crystals of felspar are numerous throughout the formation. As felspar is so prevalent, and as atmospheric in¬ fluences are so powerful, it is not surprising that large tracts of the granite are disintegrated, and in some places even decomposed. But harder—and in general finer-grained—masses are often imbedded in the softer varieties ; and, when the latter yield to degradation, the former stand out in striking, sometimes indeed in fan¬ tastic, relief. * Captain Herbert’s Geological Map indicates a fourth near Kurn Tryag.— “Journal of the Asiatic Society of Bengal xii. (n.s.) Part ii., 1843. 3 Deposits of North-western India. The rocks near Dwarra Hath, divided by highly inclined joints into parallel courses , layers, or slices , which are alternately—of hard and siliceous* * * § —and of soft, disintegrating, felspathic, and talcose granite, thus strikingly illustrate the connexion subsisting between their structure and composition. The principal joints bear respectively about north and south,')' 10°—20° S. of E. and N. of W., and the third series nearly N.E. and S.W.: the bedding £— rarety horizontal—inclines sometimes one way some¬ times another, but usually towards the slope of the surface. The massive structure which prevails in the central granite, gradually passes into thick-lamellar,—but still crystalline, towards its confines; where it is overlaid by yellowish-brown mica-slate, in which talc also is often present. Isolated patches of the first rock are imbedded in the second; and of the second in the third near the limits of the respective series,§ on the mountain side, south-west of Almora. Veins of fine-grained granite—■ sometimes very broad—traverse the mica-slate in glens which feed the Punaar, a tributary of the Surjoo. Except a little gold mixed with the debris of granite|| * The beautiful but grotesque, and sometimes indecent, carvings on the Hindoo temples at this spot are executed in granite of the neighbourhood. f Mr. Enys, London and Editi. Phil. Mag., i. (1833) p. 322. | Messrs. Schlagintweit determined the magnetic variation at Nyee Tal, in May, 1855, to be 4° 0' 10 v E. § “ East of the village of Dhoveet * * the rock may be called a gneiss, but “.it exhibits small patches * * * * of the most regular micaceous schist, * * * “ and again of the most legitimate granite.” Capt. Herbert, Journal of the Asiatic Society , xn. n.s. (1843) p. cxxxn. || Captain Herbert obtained a specimen of granite which enclosed a speck of gold, from the bed of the Aluknunda near Kedarnath. Asiatic Researches , Part I. (1829) p. 236. B 2 4 W. J. Henwood, on the Metalliferous and gneiss, in the Aluknunrla at Chetoa Peepul,—in the Pindur near Kurn Pryag,—and in the Ramgunga # between Kala Bun and Gunnai, no metalliferous deposit has yet been discovered in either of these rocks. The mica-slate is seldom productive of copper, except at a distance from the granite and gneiss, and where talc is also plentiful; there, too, the veins — exclusively siliceous in the lower parts of the series — generally contain likewise notable quantities of lime. (a.) At Kurrye,f near Bagesur, pearl-white talc and calc-spar alternate in thin beds, which bear about S.E. and N.W., and dip 35°—45° SAV. The calcareous strata are rarely mixed with other substances; but the talcose beds, at intervals, include kidney-shaped masses of quartz; which are sometimes tinged with earthy brown iron-ore,—are often irregularly spotted and streaked with copper-pyrites,—and now and then with purple copper-ore. Traces of the carbonate of lime and of pearl-spar occasionally appear in the quartz; but at such times copper-ore is rarely or never present in the rock; although a thin incrustation of the green carbonate of copper frequently invests the quartzose nodules. (Z>.) Similar alternating beds of talcose and quartzose matter have been wrought at Rai\ and Bellar in * Mr. Commissioner Batten, Official Reports on the Province of Kumaon , (Agra, 1851,) p. 157. Moorcroft and Trebeck, Travels in the Himalayan Pro¬ vinces, , i. p. 7. f Mr, Commissioner Batten, Official Reports on the Province of Kumaon, (Agra, 1851,) p. 313. + Capt. (now Lieut. Colonel) Drummond, Journal of the Asiatic Society, No. lxxxiii. (1838) p. 935. Mr. Commissioner Batten, Official Reports on Kumaon, (Agra, 1851,) p. 274. Report on the Metalliferous Deposits of Kumaon and Gurhwal. Selections from the Records of Government , (Calcutta, 1855,) p. 9. 5 Deposits of North-western India. Gungolee, and have afforded copper-ore in both, as well as a little blende also in the latter: but the ancient works are ruinous, and nothing is now discoverable, save that the direction is in the former about 30° N. of E. and S. of W., and in the latter nearly N. and S. (c.) A few specks of iron and copper-pyrites and stains of the green carbonate of copper occur in beds of talc- slate bearing 10° S. of E. and N. of W., which alternate with large and irregular masses of dusky siliceous lime¬ stone at Goron ,* * * § near Petoragurh. Some ancient mining works in their steep craggy slopes are now covered with rubbish. ( d.) The district of Seera consists for the most part of clay-slate,f in which traces of copper-ore are numerous.J Several neighbouring deposits have been examined, but continued operations are confined to one ;§ which— parallel to the bedding of the adjoining rocks— bears nearly E. and W., dips N. about 50°, and is generally from two to three feet wide; though at intervals it is both enlarged and enriched by union with small metal¬ liferous lines of quartz. * “ Beside the bed of dolomite, beds of talc slate are found, and in this rock is “ situate the copper mine, which is, however, worked on a very small scale, pro- “ ducing only 50 Rupees per annum.” Captain Herbert, Journal of the Asiatic Society, xn. n.s. (1843) p. cxvi. t “ At Seera, argillaceous schist prevails * * * of a deep iron black colour, “ with straight laminae, very hard and very brittle.” Captain Herbert, Ibid, p. cxix. t Mr. Commissioner Batten, Official Reports on Kumaon, (Agra, 1851,) p. 281. § Mr. Commissioner Traill, Asiatic Researches, No. xvi. (1828) p. 137. Captain Herbert, Ibid, Part i. (1829)-p. 243. Mr. Commissioner Lushington, Journal of the Asiatic Society, No.cxxxvm. (1853) p.468. Captain Drummond, Ibid, No. lxxxiii. (1838) p. 936. Selections from the Records of Government, (Calcutta, 1855,)p. 10. 6 W. J. Hen wood, on the Metalliferous The principal ingredients are quartz and talc; but the former—frequently mixed with small quantities of calcareous matter—is by far the more abundant. Generally they are more or less mixed; though some¬ times one, sometimes the other mineral almost exclu¬ sively prevails: but even then masses of the rarer are commonly imbedded in the more plentiful constituent.* Often too mere laminae of pearl-white or pale-yellowish talc form, as it were, unctuous joints in the quartz, and give a veined structure to the whole mass. Although iron-pyrites is sometimes found in small quantities, copper-pyrites is by far the more abundant ore: both —in short and narrow veins, small lumps and scattered granules,—occur almost exclusively in the siliceous parts of the formation. The richest portions are however scarcely ores of second quality, f Small drusy cavities are not uncommon; and the crystals of quartz and of pearl-spar which line them, are sometimes coated with iron—and more rarely with copper—pyrites. Many traces of ancient mining works yet remain near Pokree between Chetoa Peepul on the Alak- nunda and the Snowy-range. * “ Hand specimens may be obtained in which both substances are separately “ observable, as well as in mixture,” Captain Herbert, Journal of the Asiatic Society, xn. N.s. p. cxix. f Eradg e-work. Pryce, Mineralogia Comubiensis, p. 234. Cornwall Geo. Trans, rv. p. 160. Mr. Henderson, Proceed. Institution of Civil Engineers, xvn. 1^58-9, p.*16. I Captain Herbert, Asiatic Researches, Part i. (1829) p. 236 ; and Journal of the Asiatic Society, xii. n.s. (1843) p. xcvi.; Mr. Commissioner Traill, Asiatic Researches, xvi. p. 130 ; Lieut. Glasfurd, Journal of the Asiatic Society, No. xc. N.s. (1839) p. 471 ; Mr. Commissioner Lushington, Ibid, xii. n.s. p. 455 ; Mr. Reckendorf, Ibid, xiv. p. 471 ; Mr. Commissioner Batten, Official Reports on Kumaon , p. 152 ; Extracts from the Records of Government (Calcutta, 1855), p. 4. Deposits of North-western India. 7 The rocks of the district are talc, clay, and chlorite slates; and copper is found in them all. (e.) At Talapoongla the prevailing formation is brownish talc-slate, occasionally alternating with thin homogenous laminae of a lead-blue colour and silky lustre.* Flakes of copper-pyrites,—now and then as much as one-eighth of an inch in width, but seldom thicker than paper, or more than an inch or two in length, and usually much shorter,—occasionally inter¬ lie the other ingredients and form an intregal part, especially of the lead-coloured rock. These laminae of ore occur for the most part in a bed four or five feet in width, parallel to the adjoining rocks, which are almost exclusively talcose. They all exhibit many small twists and contortions, but their general strike is about 10° N. of E. and S. of W., and they dip N. about 10°. Two series of joints, bearing respectively about E. and W., and 15° E. of S. and W. of N., traverse indifferently the earthy and the metallic members of the series. (/.) The Danda mine is situate near the top and the Thala at the bottom of a rugged and precipitous mountain-side; of which the ridge is talc-slate, the middle chlorite-slate, and the base of both in thin alternating layers. The same strike —about E. and W.; the same dip— N. 30°; the same single series of joints—bearing E.N.E. * “ Chloritic schist * * * continues to near Pokree, occasionally giving place “ to talcose schist, occasionally to talcose quartz rock. Near some of the old “ galleries of the copper mines worked here are beautiful specimens of an emerald “ green straight laminar slate with high lustre.” Captain Herbert, Journal of the Asiatic Society , xii, n.s. p. xcyi. 8 W. J. Henwood, on the Metalliferous and W.S.W.; and the same fissile structure, are com¬ mon to both. The chlorite-slate is at intervals interlaid with ir¬ regular lenticular beds of quartz, few of which exceed three feet in length or six inches in thickness, and most of them are much smaller. Chloride matter is some¬ times thinly diffused through the quartz, and it is also spotted with iron sparingly mingled with copper-pyrites, from which a slight efflorescence occasionally incrusts the surface. Fig. 1. DANDA MINE. Section. A Talc*slate. a Metalliferous quartz. B Chlorite-slate b Joints. These beds of metalliferous quartz,—owing perhaps to some play of affinities having induced differences of composition or structure,—are larger and more numer¬ ous in the centre than towards the sides of the slices into which the slates are divided by their nearly vertical joints. Generally, indeed, each slice contains its own system of beds, which are thickest towards the middle Deposits of North-western India . 9 and die out as they recede. Although in adjoining masses the beds are seldom on the same plane, one is occasionally prolonged into contiguous slices; even then, however, it dwindles at the joint and enlarges in the interior. (< 7 .) About twenty years ago* the Ckowmittee mine— the only one now worked in the neighbourhood,—was selected for an experiment at the expense of Govern¬ ment ; and thus,—though neither the most interesting nor the most productive,—and though the trial was unsuccessful,—it has become the most generally known copper-mine in the North-West Provinces. Two galleries were opened, one above another, by native miners; and more recently under European superintendence, three others at different, but less eleva¬ tions ; the upper of these is, however, the only one now existing. All five galleries have followed the contact of differently coloured rocks ; which, bearing about 15° E. of S. and W. of N., and dipping 50° N. of E., exactly coincides with the cleavage of both. The laminae of the lower rock,— of homogeneous texture, leaden hue, and silky lustre,—are interlaid by minute scales of yellowish talc; whilst the upper, of pale-buff passing into lemon colour, is almost entirely talcose: their structure, alike, is extremely fissile. At and near their junction both rocks,—but the lower especially,—are interlamellated sometimes with copper-pyritesf, some * Mr. Commissioner Lushington, Journal of the Asiatic Society, xn. n.s. p. 456; and Official Reports on Kumaon, p. 369. f Ante, p. 7. C 10 W. J. Hen wood, on the Metalliferous times with purple copper-ore, and more rarely with both. The plates of ore are generally about the thick¬ ness of paper, but at times they widen to one eighth of an inch, and lumps as big as a filbert are occasionally, though seldom, found ; now and then as much as six— they are commonly less than two—inches in length and breadth, and many are still smaller. Short, thin, and irregular beds of quartz, at times mixed with earthy brown iron-ore (gossan* * * § ), frequently interlie the slates in the same neighbourhood ; and are not only trans¬ fused with ores similar to those of the metalliferous laminae they touch, but are spotted with vitreous and black copper-ore; and incrusted, sparingly with the blue,—and more plentifully with the green—carbonate of copper also. The general produce, however,— inferior in quality to that of Seera —would not be considered as ore even of second classj by English copper-miners. (A.) The Rajah's ,§ the Thala, and other small copper mines have been from time to time opened in the same neighbourhood, either by the natives or by Government; but as some resemble those already described, others are closed, and all are now abandoned, further mention of them seems unnecessary. (i.) The high and picturesque cliff which forms the * Cornwall Geol. Trans, v. p. 204. f Ante , p. 6. J Pryce, Mineralogia Comubiensis, p.236; Cornwall Geol. Trans, iv. p. 166; Mr. Henderson, Proceedings of the Institution of Civil Engineers , xvii. (1858) p. 16. § Mr. Commissioner Lushington, Journal of the Asiatic Society, xn. N.S. p. 460; and Official Reports of Kumaon, p. 373. jyeposits of North-western India . 11 left bank of the Ramgunga, at Al Agur mine,* some three miles north-west of Lohba, an ancient native fort now in ruins, consists of dark-green chlorite-slate, of which the cleavage-planes bear about S.E. and N.W., and dip S.W. 30°. Everywhere more or less siliceous, the almost exclusively quartzose character of one bed, cropping out in the precipice, is varied only b}^ the interposition of some slaty laminae, which, conforming to those of the adjoining rock, thus impress a veined or lamellar structure on the whole. Narrowing; from ten feet at the surface, to about three at fifteen fathoms deep, the slate, a conspicuous ingredient in the shal¬ lower parts of the bed, gradually disappears in the deeper; and ochrey pale-brown iron-ore, of but occa¬ sional occurrence at first, becomes at length abundant. The green carbonate is the only ore of copper found in the upper part of the formation; but, though seldom or never entirely absent, it is in a great measure re¬ placed by vitreous and purple ores towards the bottom of the mine. (j.) The mine of Dhunpoorc ,j~ about ten miles south-west of Kurn Pryag, is wrought in the northern extremity of a mountain range perhaps five thousand feet above, and immediately south of Chetoa Peepul on the Aluknunda. * Mr. Deputy Becket, Selections from the Records of Government , n.w.p. Part xiii. (1853) p. 73. t Mr. Commissioner Traill, Asiatic Researches, xvi. p. 137. Captain Herbert, Ibid, (1829) Part i. p. 241; Journal of the Asiatic Society, xn. n.s. p. c. Mr. Commissioner Lushington, Ibid, p. 463. Mr. Reckendorf, Ibid, xvi. (1845) p. 474. Mr. Commissioner Batten, Official Reports on Kumaon, p. 154. Extracts from the Records of Government, (Calcutta, 1855,) p. 6. c 2 12 W. J. Hen wood, on the Metalliferous The slate rock of the neighbourhood, generally blue though sometimes buff or brownish, has mostly a silky lustre, and—by the interposition of thin, crooked, and irregular quartzose beds—is much contorted, and ex¬ tremely fissile.* The quartz is mixed with calcareous matter, and—though in smaller proportion—the slate is seldom destitute of it. The laminse bear about E. and W.; but they are so distorted that it is scarcely possible to assign them an amount or even a direction of dip.f A bed of siliceous limestone,J sometimes greyish- white, sometimes pink, but usually of a pale buff colour, interlies the slate; though slightly undulating in different directions, and seldom quite level for any great distance, it may—on the whole—be considered nearly horizontal; its thickness is generally about a foot, but under special circumstances—to be mentioned presently—it enlarges, for short distances, to fifteen, and occasionally even to twenty, feet. The slate and limestone are alike traversed by two sets of joints; one—nearly parallel to the strike of the lamination—bears about E. and W.; the other between * “ In the ascent to Dhunpore quartz rock * * * passes * * * into a very “ thin slaty rock of a yellowish colour, * * * composed apparently of quartz “ with some talc. The laminae of this are not above a tenth of an inch in thick- “ ness * * * * are often bent and curved. * * * It passes into argillaceous “ schist * * * variously mixed with limestone more or less pure.” Captain Herbert, Journal of the Asiatic Society , xn. n.s. p. xcix. + “ The rock in the neighbourhood of Dhunpore is distinguished for its “peculiar shattered and fissured aspect, no trace of stratification being obser- “ vable except on the great scale. The irregularity of the strata is great, and “ the change of dip frequent.”— Ibid , p. c. J “ This * * is evidently connected with the siliceous limestone on the Dhohree “ side ” (of the mountain), “ in which also a mine is worked, but the produce is “ inconsiderable.”— Ibid, p. c. Deposits of North-western India. 13 N. and S., and 10°-15° E. of N. and W. of S.; both series are highly inclined, and in bearing and dip are subject to slight though frequent flexures, sometimes towards one—sometimes towards the other — side. Generally speaking, the joints exhibit a mere contact of two smooth faces; in some places, however, they enclose slices of the rock adjoining, in others thin plates of purple-copper-ore, and often the ore and the rock are mixed. The non-metallic ingredients, thus in¬ cluded, are divided into somewhat lenticular masses by Fig. 2. Section. the undulation and interlacing of numerous minor joints, which are often lined with clay, and marked with striae, sometimes parallel sometimes diverging, but rarely preserving an uniform direction either on opposite sides of the same mass, or even on the same surface, for more than a few inches.* At these inter¬ sections the ore is also usually marked with slicken- sides.f These enlargements though—on the nearly N. and S. or normal joints especially—numerous are seldom of great extent; for the undulation which in one direction separates the faces, in the opposite brings them again together.* A third set of joints bears about 30° E. of S. and W. of N., but it is very slightly developed. * Cornwall Geol. Trans, v. pp. 53, 172; Table xvm. t Ibid, p. 181; Table xxix. 14 W. J. Henwood, on the Metalliferous The joints of both the principal series widen and become more metalliferous as they approach the nearly horizontal bed of siliceous limestone; and small as they are above, they then often reach a width of six inches, and are occasionally still larger.* The characteristic deposits of ore occur, however, in neither of the two systems of transverse and nearly vertical master joints; Fig . 3. DHUNPOORE MINE. a Joints E. and W. C Bed of siliceous limestone. b Joints E. of N. and W. of S. Z Masses of copper-ore, at the contact of the joints with limestone. nor even where they merely intersect; but at those points only where such intersections meet the upper face of the calcareo-siliceous bed,j' which is generally thicker at these places than elsewhere. The rock sur- * “ The seams of ore are said to he one foot thick at times, but generally they “ are less than one inch thick, and anything more than that is considered a “ prize by the miners.” Mr. Commissioner Lushington, Journal of the Asiatic Society , xn. n.s. p. 464. f “Above” (the horizontal vein the ore) “dwindles away to the size of a “ reed.”— Ibid, p. 464. Deposits of North-western India . 15 rounding these double intersections is often for some distance richly charged with purple copper-ore and— less frequently—with copper-pyrites; from which veins —more pyritous than the main body—penetrate, as well the limestone as the adjoining slate, in all direc¬ tions. This impregnation extends—in extreme cases— as much as twenty-five or even thirty feet, but generally less than half that distance; and in rare instances no increase either of size or produce accompanies these double contacts; but neither joint nor neighbouring rock is then metalliferous. With these unimportant exceptions therefore, whether we approach the lime¬ stone on the line at which the two systems of joints intersect, or the intersection of the joints on the plane of the limestone, the width and riches of the joints simultaneously increase. As the joints of each system Fig. 4. dhunpoore mine. Plan. preserve a parallelism amongst themselves, and the 16 W. J. Hen wood, on the Metalliferous systems are nearly at right angles to one another, whilst the ore occurs chiefly at their intersections; the forma¬ tion has somewhat the appearance of a chess-hoard with spots at the angles of each division, which is in fact rather rhombic than square. From the same point therefore, the little masses of ore present on one view a parallel, on the other a transverse, disposition. This symmetrical arrangement on a still larger scale has long been recognised in Cornwall, in the proverbial phrase of “ ore against ore.” # The limestone as well as the slates above and beneath it have been long and carefully examined by native miners; but as the upper have been the most productive —they have also been the most constantly and ex¬ tensively wrought—parts of both formations; to them, therefore, these remarks exclusively relate. I cannot leave Dhunpoore without mention of the view it commands,f which—once seen—can never be forgotten. More than five thousand feet beneath, the Aluknunda fresh from the snows rushes through a yawning chasm * Mr. Came, Corn. Geol. Trans, m. p. 78; Ibid, v. pp. 87*, 215, 233. f “ The view from the crest of the Dhunpoor ridge is beyond description “beautiful and majestic. The great castellated peaks of Budrinath rise directly “ in front of the spectator, and on either side of these as far as the eye can reach, “ appears a long succession of other snowy peaks, varying in form and altitude ; “ but all and each surpassingly grand and sublime. Gungotri, Kedarnath, and “Budrinath to the left, Trisool, Nundadevi, Purychoola, and Kylas to the “ right, fully merit the title bestowed upon them by the Shastra, of ‘ Mountain “ Kings.’ ” Mr. Commissioner Lushington, Journal of the Asiatic Society , xn. n.s. p. 463. “ The Dhunpoore range is noted for its magnificent scenery.” Mr. Commissioner Batten, Official Reports on Kumaon, p. 154. Deposits of North-western India . 17 towards the low-lands; where, soon abating its fury, it quietly meanders amidst smiling meadows. The sugar-cane flourishes, and plantain, orange, pomegranate, apricot, and other fruit trees thrive in many warm valleys and deep secluded glens, amid the broken mountainous tract, which rises in successive ridges from the river to the limits of vegetation; and, though still the haunt of tigers, bears, and other beasts of prey,* is often richly wooded, and sprinkled with terraced corn-fields, pastures, and villages. Seemingly almost within hail, but really twelve or fifteen miles distant, the forests are succeeded by snows ; over which—as far as the eye can reach—the view ex¬ tends not only to the highest peaks of the Himalayas —the boundary of British India—and through the passes between them into Thibet, on the north ; but far beyond the frontier of Nepal on the east, and to the ridges of Jumnotree on the west. The general elevation of the region is from twelve to twenty thousand feet; though its highest ranges exceed twenty-five thousand.^ A few steeps and cliffs of naked rock alone pierce the perpetual snows, which cover the thousand square miles of this awful but magnificent solitude. * “ Owing to the situation of some of the villages near the forest, and the “ difficulty experienced by the few inhabitants in preserving themselves and their “ crops from the ravages of wild beasts, a decrease of the Government demand “ * * * was found necessary.” Me. Commissioner Batten, Official Reports on Kumaon, p. 153. f “In a line of 500 miles two summits are found exceeding five miles in “perpendicular height, * * * connected to appearance by a regular series of “peaks of very little inferior elevation. * * * If we confine ourselves to 21,000 “ feet, we may find a connected line of such peaks extending through a distance “ of 1,000 miles.” Captain Herbert, Journal of the Asiatic Society, xn. n.s. p. xxn. D 18 W. J. Henwood, on the Metalliferous $ (k.) Near Tarag-ke-Talf a small lake which supplies a tributary to the Ramgunga about two miles east of Gunnai, small quantities of copper-ore occur in a cliff, the brow of which is grey siliceous limestone, and the base of mottled grey and white calcareo-siliceous slate; the strike of the beds is S.E. and N.W., and their dip —S.W. about 30°. One series of joints is parallel to the slaty structure, another bears 10°—15° W. of N.; both are faced with unctuous clay, and their outcrop is incrusted with calcareous stalagmites, occasionally tinged with the green carbonate of copper. The metalliferous bed— eight or nine feet in thickness—is parallel both in bearing and in dip to the adjoining slate, and differs from it only in being more siliceous towards the middle, and more calcareous at the sides. The quartzose ingredients are thinly spotted with cop¬ per-pyrites, and small quantities of the green carbonate of copper occur amongst the calciferous slate beneath. Copper-ore has been wrought in a few other locali¬ ties; but it is even less plentiful in them, than in those already described. (B.) Iron-ore abounds in many parts of both Pro¬ vinces ; but hitherto it has not been found as deep as the gneiss formation. The district of Chowgurhka exhibits many traces of ancient mining, and a few iron-mines are still wrought there; they are, however, so far apart that the metalliferous deposits have been traced neither * Mr. Commissioner Batten, Official Reports on Kumaon, p. 317. Extracts from the Records of Government (Calcutta, 1855), p. 8. Deposits of North-western India . 19 throughout the district, nor even from one mine to another. (a.) The furnaces at Nadhoolee are in great measure, and those of Maarum are entirely,—supplied with ore from the Sakloo mine, an open-work in a massive talcose rock near Dhoora Devi. # Operations have ex¬ tended to a depth of nine fathoms, and—without having reached the lower (foot)-wall —to a width of nine or ten feet, on a bed which bears nearly N. and S.,—dips E. 50 3 —5S°,—and consists principally of compact but partly also of earthy-brown iron-ore; mixed with quartz, in greater or smaller proportion throughout,t especially towards the interior. Lumps of copper pyrites, sometimes associated with purple copper-ore, are—at intervals—imbedded in the iron-ore, in which likewise drusy cavities are occasionally lined with the rhomboidal arseniate of copper. The quantity of cop¬ per-ore is however so small that it has attracted but little attention.J (5.) At Agur,\ in the same district, large isolated * On the edge of a small grassy glade, a temple,—three tall sculptured stones, —a slate cromlech ,—and one of the large iron-chain swings —often seen in places held holy by the natives, are shaded by a sacred grove of noble Deodars (Pinus DeodaraJ, under which I encamped at Dhoora Devi. f Professor Warington W. Smyth, Quarterly Journal , Geol. Soc. xv. p. 107. X Extracts from the Records of Government (Calcutta, 1855), p. 22. § A temple of rude workmanship and several small cromlechs of slate have been set up in the oak (Quercus semecarpifolia) forest at Agur. Some of the cromlechs are horizontal, but others are inclined at angles of from thirty to forty degrees. “ The flat-topped cromlechs are used indifferently as altars or as seats ; “ for though sometimes covered with offerings of rice and flowers, the natives “just as often sit and rest their burdens on them. The inclined ones generally “ rest on the ground at one end, and are propped at the sides in such a manner “that about two-thirds of the circumference is sheltered. Under these are sxis- “ pended small rudely made iron lamps, which generally contain oil, but are “ lighted only when religious rites are solemnized.” Proceedings of the Royal Institution of Cornwall (1855), p. 20. Extracts from the Records of Government (Calcutta, 1855), p. 23. D 2 20 W. J. Henwood, on the Metalliferous masses of compact—and considerable quantities of scaly—brown iron-ores occur in a matrix of talc about two feet in thickness; which—coinciding with the structure of the adjoining talc-slate—bears nearly S.E. and N.W., and dips S.W. 15°—20°. # (c.) At Luttea Gar , an abandoned mine in the same neighbourhood,')' the refuse—consisting of cellular and friable quartz, mixed with earthy-brown iron-ore (gos¬ san ) £—contains stones of copper-pyrites and is spotted with the green carbonate of copper. (d.) The Bunna mine near Ockulgurh is wrought for some fifteen fathoms in length, and to about forty- five in depth, from four openings—one above another —in the side of a mountain which bounds the Punaar valley on the north. The rock—consisting of pale yellowish talc and quartz—is of thick lamellar struc¬ ture ; its beds—like those of the metalliferous deposit which interlie them—bear about 16° S. of E. and N. of W., and dip 40°—70° S. The ore—exclusively specular-iron—is but slightly mixed with the adjoining ingredients,§ and is from ten to twelve feet in width. Towards the bottom of the mine it is divided into two —of which the lower portion is much the thinner—by a (horse) mass of rock, similar in composition to that of the (walls) sides, and coincident both with it and with the scales of ore in lamination. Eastward this * Extracts from the Records of Government (Calcutta, 1855), p. 23. f Official Reports oti Kumaon , p. 313. % Cornwall Geol. Trans, v. p. 204. § The only difference between this formation and the Jacotinga of Brazil, is in the former containing neither Manganese nor Gold, whilst the latter affords both. Deposits of North-western India . 21 included slice of talcose rock maintains a tolerably uniform thickness of between two and three feet; but westward it becomes gradually narrower and ultimately dies out, as it also does upward,—disappearing at some distance from the surface. Somewhat lower in the series the rocks are almost entirely quartzose, and are then largely used in the construction of furnaces. (e.) The district of Agur,* long the most extensive field of mining industry in Kumaon, though still rich in iron-ore, is now reduced to comparative insignifi¬ cance, bv a thriftless destruction of the forests, which has at length deprived the smelters of fuel. The prevail¬ ing rock is talcose-slate; always more or less quartzose,f on the north ; but often alternating with layers of clay- slate towards the south. Although the beds have a * “ The villages of Agur, whence the inhabitants are called Agurees, belong “ to the tribe of Sones, whose especial avocation is, the working of the iron mines “ and preparing the ore, not only of the Lohakote ridge itself, but throughout “ the province. They are Soodras by caste, and will not labor at the actual work “of lohars or blacksmiths. * * * The Agurees remain at home from May till November, and during the rest of the year they and their families are to be “ found at the several mines, some of the best of which are to be found in Ram- “ gurh itself. The main body, after sowing their wheat and barley, however, “ collect at Khetsaree, where the mild climate and cheap food, besides the plentiful “ ores, hold out great attractions. * * * The terms on which the lessees of the “ mines are obliged, in the absence of competitors, to engage the Sones, are “highly favourable to the latter.” Mr. Commissioner Batten, Official Reports on Kumaon, p. 303. f u Below the pass we have a white schistose quartz rock of rather arenaceous “ composition, * * * which evidently contains talc, * * * and perhaps some “ felspar.” Captain Herbert, Journal of the Asiatic Society, xn. n.s. (1843) p. xciv; Asiatic Researches, I. p. 255. “ Rich mines of red hematite are found and worked in the quartz rock.” Captain Strachey, Quarterly Journal of the Geol. Soc., vn. (1851) p. 298. 22 W. J. Henwood, on the Metalliferous prevailing direction of 10°—20° E. of S. and W. of N.; portions of their numerous short and abrupt flexures bear nearly at right angles to the general strike. Within a distance of about six miles the iron-mines of Shealgar , Guarocoolee, Lusghanee , Nutoa Kanh , Galla, Dhoora Kanhi, Capua , Choocoola , Bunna , Purturbura, and others, are wrought—sometimes as much as twenty fathoms deep, but generally much less—on the same bed, or system of beds of ore,— which,—oblique, as well to the mountain-range it tra¬ verses, as to the glens and deep ravines which furrow its sides,—seldom differs widely from the strata in general direction, though they are rarely quite parallel* except where they touch. For a short distance on either side of the iron-formation the rocks cease to maintain their ordinary bearing; and approximating more and more closely to its strike and dip as the distance between them diminishes, they assume—at length—an almost perfect parallelism at their contact. But small as the extent of this paral¬ lelism in each case necessarily is, every rock of the district assumes in its turn a similar position; and whether the iron-formation be ap¬ proached on one side or other in the normal direction of the strata, their deflected portions which adjoin it, Fig. 5. Plan. a Bed of iron-ore. * Captain Herbert, Journal of the Asiatic Society , xn. N.s. (1843) p. xcm. Deposits of North-western India. 23 are—in the apt mining language of Cornwall—found on the left-hand* The rich repository of Nutoa Kanh the metalliferous deposit consisting in great measure of specular iron-ore, mixed with some quartz, and a little talc, is for some distance divided into four separate beds by lenticular layers of quartzose talc-slate, similar to that on either side. These however soon die out, and within a few fathoms the beds of ore re-unite, both in length and depth. The mutual relations, universal between metalliferous deposits and the rocks which adjoin them,f are seldom so manifest as they are in this district. The iron for- mation—though exhibiting many inflections—main¬ tains a general direction about 25°—40° E. of S. and W. of N.; and whilst partaking—more or less—the * Mr. Thomas, Report on a Survey of the Mining District of Cornwall (1819), p. 22, Note. Mr. Carne, Cornwall Geol, Trans., n. p. 86. My own Papers, Ibid, v. p. 5. + Carew, Survey of Cornwall (1602); Price’s Edition, p. 10; Lord De Dunstanville’s Edition, p. 33. Borlase, Natural History of Cornwall (1758), p. 147. Pryce, Mineralogia Cornubiensis, p. 94. M. Jars, Voyages Metal- lurgiques, hi. p. 190. Dr. Thomson, Travels in Sweden , pp. 218, 220. Dr. Berger, Geol. Trans., I. p. 164. Mr. Carne, Cornwall Geol. Trans., iii. p. 78. Dr. Boase, Ibid, iy. p. 441; and Primary Geology, p. 168. Prof. Sedgwick,— Address to the Geological Society,— Phil, Mag. and Annals, ix. (1831), p. 284. Mr. Taylor, Reports of the British Association, n. (1833) p. 23. Mr. Burr, Mining Review, No. yiii. (1836) p. 218. Mr. Fox, Report of the Royal Cornwall Polytechnic Society (1836), p. 84. Mr. Bakewell, Introduction to Geology (4th Edit.), p. 430. Dr. Macculloch, System of Geology, I. p. 386. Professor Phillips, Encyclop. Metrop. Geology , p. 772; Encyclop. Britan, (reprint), p. 272; Cabinet Cyclop ., ii. p. 134. Sir H. T. De la Beche, Geological Manual (3rd Edit.), p. 492; Researches in Theoretical Geology, p. 218; Report on Cornwall, §c., p. 335. M. Domeyko, Annates des Mines (4me serie), ix. p. 437. M. Moissenet, Ibid (5me serie), xi. p. 418. My own Papers, Phil. Mag. and Annals, x. (1831) p. 460 ; Edin . New Phil. Journal, xxn. pp. 156, 271; Annals of Electricity, i. p. 124; Annales des Mines, xi. (1837) p. 586; Cornwall Geol. Trans., v. p. 189. 24 W. J. Henwood, on the Metalliferous mineral composition of every rock in the district, as it touches each in succession, it imparts at the same time its characteristic colouring to the adjoining portions of all. Nor are the changes in its metallic, less marked than those of its earthy, ingredients; for yielding the micaceous variety of specular iron-ore only whilst amongst the quartzose talc-slates of Nutoa Kanh and other mines north of the Ramgurh or Khurna valley; in the alternating talc and clay-slates of Bunna and Purturbura on the south, the brown and magnetic ores alone prevail. But, though this bed has been examined in every part of its course; in common with all other metalliferous deposits, it is rich at intervals only. Its different connexions and changes are however briefly shown in the accompanying columns. (Table i.) 25 Deposits of North-western India. The thinly laminated rocks which overlie the great iron-formation consist, for the most part, of quartz and micaceous specular iron-ore in almost innumerable alternations. Gradually, however, the latter is replaced by chlorite or some kindred mineral* * * § ** of bluish-green colour; and at the same time, lime becomes an ingre- dient.f (/.) At Pahlee, near the village of Ramgurh, a glossy blue homogeneous slate is interlaid by a bed of micaceous specular iron-ore about two feet in thickness,£ which bears about S.E. and N.W. and dips towards the N.E., but whether it is independent of or subordinate to the great iron-formation of the district, has not been ascertained. ( g .) About two miles from the mines of Bunna § on the east, Agur || on the west, and about twice that distance from the nearest mine in the Ramgurh or Agur district,^—all in rocks more or less talcose,— the mine of Pahlee ## —the second of that name—is wrought, in clay-slate, within the district of Kalee * “ Below the pass, we have a white schistose quartz-rock of rather arenaceous “ composition.” Captain Herbert, Journal of the Asiatic Society, xn. n.s. p. xcm. f “It is exchanged for a very hard bluish-grey rock, with much the external “ aspect of limestone, but non-effervescent, or very rarely so, and in a low de- “ gree.”— Ibid, p. xciii. J “ At Ramgar, on the road from Bhamaori to Almorah, the red hosmatite “ passes into the variety called scaly iron-ore, consisting of loosely cohering “ glimmering particles of a steel-grey or iron-black colour, strongly soiling and “ feeling unctuous to the touch. This bed, though distant many miles from that “ at Dhaniakdt, is, I think, connected with it beneath, and the two form one and “ the same deposit.” Captain Herbert, Asiatic Researches, i. p. 254. § Ante, p. 20. || Ante, p. 19. H Ante, p. 21. ** Extracts from the Records of Government (Calcutta, 1855), p. 21. E 26 W. J. Hen wood, on the Metalliferous Kumaon, on one of the upper tributaries of the Punaar. Dipping, as the bed of ore dips, 18°—20° N.W., and parallel in direction as well to it, as in great measure to the undulations of the surface, the laminae bear in some places 10° N. of E. and S. of W., and in others about N.E. and S.W. The general texture of the rock is homogeneous, and the colour dark blue; occasionally however it is interfoliated with thin plates of quartz and ferruginous clay, and has then a chocolate-brown hue. The rock and the ore are alike traversed by two series of joints; one bearing nearly S.E. and N.W., the other 25° E. of N. and W. of S. Though many acres of the surface exhibit numerous traces of ancient mining, operations are at present limited to the neighbourhood of two shafts, which have been sunk to a depth of about twelve fathoms, on a bed of compact brown iron-ore, often mixed with quartz, and frequently also with slaty matter; its thickness varies from a foot and a half to three feet, and may average about two feet. Thin laminae of iron-ore inter¬ lie the rock on either side of the principal bed, and in them small quantities of copper-pyrites are occasionally found. (h.) At Mungla Lehh* in the district of Dheeanee- row, innumerable indications of mining occupy an area of perhaps half a mile square in the clay-slate, which * “ There are iron-mines at Munglalekh in Dheeanee-row, of which the ore is “said to be the best in the province; certainly the iron made from it is most “ esteemed by the plains traders.” Mr. Commissioner Batten, Official Reports on Kumaon, p. 296. Extracts from the Records of Government (Calcutta, 1855), p. 20. 27 Deposits of North-western India. succeeds the mica slate penetrated by granite-veins,* subordinate to the granite of Deo (Devi) Dhoora.')' * Ante, p. 3. f “ The temples and other objects of Pagan worship on the summit of Deo “ (Devi) Dhoora, a granitic mountain some miles south-east of Almora, are “considered of peculiar sanctity, and much visited by Hindoo devotees. With- “ out,—but very near,—the shorter sides of an oblong square enclosure, sur- “ rounding the two principal temples, which face opposite points, as well as in “ front of a smaller place of worship, about a furlong to the south-east, three “ large blocks of granite, respectively about four feet, two feet and a half, and “ one foot above the general surface, afford tolerably level spaces of several feet “ area. The upper face of each exhibits five pits or basons of about a foot in “depth and six or eight inches in diameter ; their brims are sharply cut, their “ sides are perfectly smooth, and no trace of disintegration appears in either of “ them. Without symetrical positions and at irregular distances from each “ other,—they are evidently artificial; but neither the priests of the temples nor “ my native attendants were disposed to satisfy enquiries as to their uses, or “ indeed relative to their religious rites generally. “ The small south-eastern place of worship,—about twelve or fourteen feet “long, by perhaps eight in breadth and height,—differs but little from the “ ordinary dwellings of the natives. It is divided within by railings into two “ unequal parts, of which the larger is for the priests and the smaller for their “ congregation. A closed cell was observed on one side, and a quantity of ashes “ on the floor of the former; the latter was empty. “When this district was overrun by Mahomedan conquerors, many of the “ Hindoo temples were destroyed, and most of their idols were broken; the sacred “ edifices are therefore now frequently made of wood. One of these wooden “ buildings has been erected within the holy precincts at Deo Dhoora, which are “ however still strewed with richly-cut stones of the original temple. One ancient “ place of native worship there, the most ruthless destroyer would find it difficult “ to mutilate. Two masses of granite of more than fifty feet square each, por- “ tions of a romantic cairn, rise from the verge of a precipice : apart downward, “ they touch above, and thus form a stupendous natural portal to a small cavern “in the rock. With admirable adaptation, a long flight of broad rough steps “ leads to this frowning entrance: but the expectations raised at its Cyclopean “ porch are disappointed by the straitened dimensions of the temple within; which “ is lighted only through the doorway and through crevices in the rocky roof. “Hice and flowers were offered on a low stone altar before the mutilated idol— “ a semi-human figure with the legs folded beneath—a representation of some “ incarnation of the Hindoo deity. A sacrifice had been offered by one of my “native attendants but a few minutes before I entered the temple; and it was “ not without horror and disgust that—on becoming accustomed to the twilight “ within—I found myself steeping in the blood of the victim which spattered the “ sides, and formed a pool on the floor. The remains of several small granite- “ built shrines still exist on the same rocky surface in which the rock-basons 28 W. J. Henwood, on the Metalliferous Sometimes of a dull pale—sometimes of a glossy dark-blue colour, but generally more or less mottled with both, the rock is of thick lamellar structure; its beds, like those of ore which interlie them, bearing about E. and W., and dipping 18°—40° N. Resembling the neighbouring rock, as well in com¬ position and structure, as in bearing and dip; three layers of slate,—the widest about five,—and the others perhaps two—feet in thickness; alternate with four parallel bands of ore; the largest of them nearly six,— the others—varying from a foot and a half to three— “have been sunk near this natural temple, and each contains a fragment of an “ idol. “ Close at hand, also, a stone of about ten tons in weight, evidently once a “ logan-rock, lies overthrown; and at least four other similar rocks,—which “ equally bear traces of having been purposely upset, crown wild picturesque “ granite cairns in the neighbourhood. An isolated granite rock of perhaps “ twelve or fourteen feet in height and six feet in diameter on an elevated part “ of the mountain, about a mile from the temples, is still an object of worship. “ In front of the small south-eastern place of worship, and very near the rock- “ basons, are two cromlechs; the larger—an oblong square of five feet in length “ and two feet and a half in width is supported horizontally at rather less than “ three feet from the ground on six vertical stones:—the smaller—a triangle of “ perhaps two feet and a half side is sustained at an angle of about thirty degrees “ from the horizon ; by props at the two inclined sides and by one corner resting “ on the ground; the space beneath thus partially sheltered from the wind for “ perhaps two-thirds of its circumference contains a small iron lamp of rude and “ primitive workmanship. Whatever the rocks in their respective neighbour- “ hoods, the cromlechs are always of slate. In Cornwall, on the contrary, there “is but a single cromlech (of schorl-rock— Capel) which is not of granite; and “ but two—the Trethevy-stone near Liskeard and the Coyte near Saint Columb— “ beyond the limits of the granite formation. “ One of the large iron-chain swings so often found in the holy-places of the “ natives (Ante, p. 19, note), hung over the basoned-rock in front of the principal “ temple, and was in constant requisition by the worshippers. “ It is vain for me to offer an idea of the rich, wild scenery of the cairn which “ forms the roof of this singular temple; enormous blocks of granite of the “most picturesque forms are piled in the strangest confusion: flowering pear - “ trees, blossoming walnuts, and noble gnarled oaks spring from the crevices, “ and patriarchal deodars overshadow the whole.” My own paper, Proceedings of the Royal Institution of Cornwall (1855), p. 19. 29 Deposits of North-western India. averaging some two feet in width. These are wrought, in four separate mines, to depths of from about four — to fourteen—fathoms. The ore most prevalent in all these beds is the micaceous variety of specular iron, in which octohedral crystals of oxydulated iron-ore are frequently imbedded; and, in either parallel—though subordinate—layers, or irregular dispersed masses,— brown iron-ore—often mixed with quartz, is also abun¬ dant. (i.) The most extensive field of Mining industry in Kumaon is on the north-eastern side of Kotelar and Khetsaree,* valleys in the division of Palee Puchaon ; which, commencing—the one near Dwarra Hath on the south-east,—the other at Simul-khetf in Ghurwal on the north-west,—points sixteen miles apart,— meet, and discharge their tribute to the Ramgunga, at Gunnai. A small extent of granitic gneiss and brownish-buff coloured micaceous slate J connects the granite of * Captain Herbert, Asiatic Researches , I. (1829) p. 255; Journal of the Asiatic Society , xn. N.s. p. cm. Lieut. Glasfurd, Ibid , No. exxxiii. (1838) p. 473. Mr. Commissioner Lushington, Ibid , xn. N.s. p. 469. Mr. Commissioner Batten, Official Reports on Kumaon, p. 317. Mr. Deputy Collector Beckett, Selections from the Records of Government , n.w.p. (Agra) Part xm. (1853) p.67; Extracts from the Records of Government (Calcutta, 1855), p. 23. f Pilgrims to Badrinath, Kedarnath, and other mountain shrines hang innu¬ merable small shreds of cloth on the trees at Simul-khet, Ghagur, and other “passes,” where the traveller northward comes suddenly on magnificent views of the snowy range. Votive offerings of the same strange kind are left on the shrubs near Madron well, to this day by parents who still bathe their weakly children there in the spring. Proceedings of the Royal Institution of Cornwall (1855), p. 21, Note. Mr. Blight, Ancient Crosses and other Antiquities in the East of Cornwall , ii. p. 71. J “ A purple scaly schist, which seems intermediate between micaceous and “ argillaceous schist, and dips E. of S., is succeeded by an earthy and subschistose “ gneiss * * * micaceous schist is then found, and resting on it a granitic gneiss “ which is connected with the * * * granite.” Captain Herbert, Journal of the Asiatic Society , xn. n.s. p. civ. 30 W. J. Henwood, on the Metalliferous Dwarra Hath with the metalliferous clay-slate of Til- poora on the south-east. In the neighbourhood of the principal mines, however, the series comprises—quartz- rock,—clay-slate,—quartzose-conglomerate,—and sili¬ ceous limestone. Overlying—at least a portion of the conglomerate at Rampoore , and immediately beneath the breccia subordinate to it at Burralgaon ,—the iron- ore in other parts of the district occurs but little above the middle of the clay-slate formation. Exhibiting numerous and—in some instances—considerable inflec¬ tions ; the system generally dips E.—N.E. 20°—45°, and bears N. and S.,—S.E. and N.W. Largely quarried as a building material, and for the construction of smelting-furnaces in the neighbourhood, the quartz-rock of Dhodulee and Simul-khet contains no foreign ingredient except the thin flakes of mica, —which disposed in corresponding—but somewhat distant planes,—impress on the mass a very thick- lamellar structure : this bears nearly N. and S.; whilst two systems of joints, which traverse the rock, range — one about 25° W. of N. and E. of S.,—the other 25° S. of E. and N. of W. The lower portions of the clay-slate formation abound in felspar, are of a pearl-white, bluish-grey, or pale-blue colour, and rather thick-lamellar structure; on either side of the iron-formation, however, the rock partakes, at intervals, almost every shade of red and brown, and is traversed by many of the interlacing curvilinear joints, so numerous at Dhunpoore*; quartz—sometimes mixed * Ante, p. 13. Deposits of North-western India. 31 with a little calcareous matter,—meanwhile, appears towards its upper confines; greenish tints,—accom¬ panied by a flinty fracture,—are occasionally exhibited, and it assumes, at length, the character of a breccia. The siliceous breccia and green flinty slate pass gradually into a quartzose conglomerate, which ap¬ pears beneath the iron-ore in the middle of the clay- slate at Rampoore; though in Khetsaree —the nearest mine—on the S.E., at Simul-khet —the next—on the N.W., and elsewhere through the district, it overlies both. Whether this unusual position be consequent on a deflection from its general strike , or on interruptions of its continuity, has not been ascertained ; as on either side of Rampoore the ore remains unwrought, and the rock is covered with earth and vegetation. The calcareous matter, more or less abundant throughout the quartzose conglomerate, is,—probably by the percolation of rain-water,—derived from the siliceous limestone formation; which—enclosing many masses of calcareous-spar,—but apparently destitute of organic remains,—extends westward no further than the range immediately east of Kotelar and Khetsaree, where it overlies the rest of the series: eastward, how¬ ever, it reaches Kala Bun—north, and Tarag-ke-Tal* south,—of the Ramgunga. Generally parallel to the structure, and to some extent partaking the nature of the clay-slate, which— except at Rampoore and Burrulgaon —bounds it on either side,—the iron-formation encloses quantities of * Ante, p. 18. F 32 W. J. Henwood, on the Metalliferous slate and quartz; sometimes separate, sometimes mixed, but always transfused with ore. To such an extent indeed do the earthy ingredients occasionally prevail, that too refractory from the admixture, for the primi¬ tive smelting-furnaces of the natives, enormous masses remain unwrought. At intervals, however, portions, almost exclusively of pure ore, are largely worked; and these invariably dip or shoot , from the granite of Dwarra Hath, towards the north or north-west.* Red iron-ore, generally compact, but now and then of fibrous structure, is as well the characteristic as the most valu¬ able part of the formation; whilst an earthy variety of the same mineral lines every crevice, and colours the adjoining rocks. Few metalliferous deposits vary in size so much as this varies in different parts of its course; for whilst at Tilpoora, in the south-east, it is but two feet and a half in width, at Simul-khet on the north-west, it has been wrought for a breadth of more than six fathoms, without having reached either of its (walls) sides. The relative situations of the mines, and other essential details are given in Table n. West of the principal deposit, at Tilpoora and Simul - khet, other parallel though much smaller beds of the same ore have been wrought in clay-slate; but whether they are independent of, or subordinate to it, has not been ascertained. At Soongareef a western tributary of the Khetsaree * Cornwall Geol. Trans, v. p. 193; vi. p. 146. f Extracts from the Records of Government (Calcutta, 1855), p. 24. Deposits of North-western India. 33 about two miles from Bonegarh , several beds of a few inches, and one as much as a foot and a half, in width, all composed in great measure of quartz, but mixed, in the former with earthy-brown, in the latter with specular, iron-ore, bear 10° E. of N. and W. of S., and dip towards the west; as also do the laminae of the brownish clay-slate adjoining them. Traces of specular iron-ore also occur in massive quartz-rock beneath the slate of Baroolee,* * * § immediately north-west of Simul-khet. No connexion has been traced between the great iron-formation of Kotelar and Khetsaree, and the small quantities of red iron-ore dispersed,—sometimes in small detached compact lumps through the strata,— sometimes in an earthy form, between the laminae and in the joints of greenish-brown, and occasionally grey¬ ish-white, fissile slate of Mehelchowree,t and diffused through quartz-rock on the top of Beansee,^ a moun¬ tain still further to the north. The district of Dhuniakote,§ comprehending the Khuloagarh 9 Hurchinolee , Tutyl , Oojowlee , Khurna , Kyroolee , and Patol , iron-mines formerly wrought in the mountains on either—but especially on the south— * Extracts from the Records of Government (Calcutta, 1855), p. 24. f Captain Herbert, Asiatic Researches , I. p. 255 ; Journal of the Asiatic Society, xn. n.s. p. cm. X Extracts from the Records of Government (Calcutta, 1855), p. 25. § Captain Herbert, Asiatic Researches, I. p. 254. Mr. Commissioner Batten, Official Reports on Kumaon, p. 300. Extracts from the Records of Government (Calcutta, 1855), p. 14. F 2 34 W. J. Henwood, on the Metalliferous side of the Kosila, is now—from the scarcity of fire¬ wood—almost abandoned. Large tracts of homogeneous, dark-blue slate of silky lustre,— upper members, probably, of the clay-slate series,—are enclosed by, and intermixed with, quartz; which,—in other districts only occasionally present, is here,—sometimes interlaid by isolated slaty laminae— often the chief ingredient. And, either diffused through, or alternating with, the slaty and quartzose rocks in short, thin, and irregular, though separate beds, cal¬ careous matter abounds in the shallower—and is rarely wanting in any part of the system. Either because the broken and impracticable surface has prevented sufficient search,— from still further changes in mineral character* than those presented in various parts of its range towards the south-east,—or from other less obvious causes, the great iron formation which crosses Ramgurh, has not been recognized in Dhuniakote although the districts adjoin on the line of its course to the north-west; nor has any metalliferous deposit been identified in a second mine of the latter. The ore most abundant in Dhuniakote is red hema¬ tite ;f but some mines have yielded earthy-brown and specular iron-ores also. * Ante, p. 24. f Captain Herbert, Asiatic Researches, i. p. 254. “ The iron ores of Dhunneea Kote (chiefly red hematite) are found in numerous “ localities * * * the mines might become very valuable in case railroads should “ be formed in Northern India. As it is they are so neglected that, our Executive “ Engineers sent to Calcutta for the iron of three suspension bridges erected in “ their immediate neighbourhood.” Mr. Commissioner Batten, Official Reports on Kumaon , p. 300. 35 Deposits of North-western India . (J.) A few low and ruinous (levels) galleries,—the heaps of glossy blue calcareous slaty rubbish broken in them,—and some scattered flakes of specular iron- ores they contain, are the only traces of ancient works now remaining at the mines in the neighbourhood, of Khuloagarh and Hurchinoolee* ( k .) The lowest in a series of small mines formerly wrought at Tutyl\ affords specular iron-ore, alternating with beds of bluish-green calcareous slate, which bear 5°—10° E. of N. and W. of S., and dip 30°—40° W. The structure is, at times, thick lamellar, and then nodules of either substance are frequently enclosed in the other: ordinarily, however, the layers of ore are merely a fraction of an inch in thickness and but a few inches in length, and on such occasions they partake every flexure and contortion of the thin-bedded and fissile rock they interlie. Parallel to the mottled blue, brown, and buff-coloured slate-rock above and below, the formation, worked in the second mine, is about four or five feet in width,—bears nearly E. and W.,—dips N. 30°—36°; and composed principally of compact brown irou-ore mixed with slaty matter, frequently contains also the carbonates of iron - and lime.J Other researches were made in a third locality, but all traces of them have been obliterated by a land-slip. (/.) The thick-lamellar quartz-rock, now and then tinged with slaty matter, which forms both banks of * Extracts from the Records of Government (Calcutta, 1855), p. 14. t Ibid, p. 16. % Ibid, p. 16. 36 W. J. Henwood, on the Metalliferous the Khurna, is—near its union with the Kosila—inter¬ laid by a bed of fibrous quartz some four or five fathoms in width, bearing about 15° S. of E. and N. of W., and dipping 35°—45° S. Often merely as a colouring matter,—more frequently mixed with quartz,—but at times the most abundant ingredient, and ever varying either in proportion or arrangement, red iron-ore,— either earthy, fibrous, or massive, is always present. The native smelter is however able to treat successfully only the richest and softest ores; in pursuit of these there¬ fore the formation has been burrowed in all directions : but though much is still in sight, owing to the scarcity of fuel, the mine has been long abandoned.* (?w.) On the edge of a precipice rising perhaps three thousand feet above the river, Oojowlee f has been wrought in a bed of limestone, everywhere more or less siliceous, of which neither the direction, dip, nor width, has been ascertained. It is however traversed by joints which bear nearly S.E. and N.W., and— flattest in the most siliceous portions—dip 26°—70° N.E. Isolated lenticular masses, and short, narrow beds of iron-ore interlie the rock in lines coincident with those of its structure. Some of these consist of specular, others of compact, brown iron-ore; the two varieties are however more frequently mixed than separate, and magnetic iron-ore is also common amongst them.J * A dove was hatching its eggs on a ledge of rock at the entrance, when I visited the mine. f Extracts from the Records of Government (Calcutta, 1855), p. 14. J A stag had made its lair amongst the grass and ferns overgrowing the abandoned works at Oojowlee. Deposits of North-western India . 37 (n.) A few masses of compact brown iron-ore mixed with the carbonate of iron are found amongst the calcareo-siliceous rubbish which has fallen on the works and covers the formation at Kyroolee*; a mine formerly wrought in the steep side of a mountain, some fifteen hundred feet above the Kosila. At Patolf about one hundred and twenty feet higher than Kyroolee on the same mountain, some openings have been made on a bed of compact brown iron-ore much mixed with quartz, and abounding in drusy cavities lined with lime, which bears about S.E. and N.W., though occasionally horizontal it has in general a slight dip S.W.,—and is from 4 to 12 feet in thickness. A few trees in the least accessible glens near Khuloa- garh have escaped the general havoc which has stripped this neighbourhood of fire-wood. These still supply fuel, as j Kyroolee and Patol furnish ore to the only furnace now worked by natives in the district. Higher in the series than any other metalliferous deposit in Kumaon, the calcareous slates of Dhuniakote are overlaid, towards the south, for several miles, by a succession of limestones and slates, J traversed by horn- blendic rocks,§ altogether destitute of every ore. * Extracts from the Records of Government (Calcutta, 1855), p. 15. f Ibid, p. 16. £ The exterior portion of the great mountain region * * * consists of a mass “ of argillaceous schists, grits, and limestones, intersected by one or more lines “ of igneous action.” Captain Strachey, Quarterly Journal of the Geological Society, vn. p. 297. § “ An outburst of considerable extent, chiefly of an amygdaloidal form, is “ associated with the formation of several small lakes. * * * Not far from these u is another small lake called Naini-tal.* * * In the immediate vicinity * * * “ are dykes of a well-defined crystalline greenstone.”— Ibid, p. 298. 38 W. J. Henwood, on the Metalliferous No part of the Sub-Himalayan range surpasses in beauty the scenery of Nynee Tal, Bheem Tal, and other small lakes in this region. Quarried for burning, although not quite free from silica, a bluish-grey limestone, the upper member of this formation, is overlaid by sandstone,* which,— slopes to the plain ;—and—rarely of great extent,—is, in some places, but a few fathoms thick. The ordinary ingredients are siliceous sand and argillaceous clay; but talc is often present also. The general hue is pale-buff or greenish-grey; occasionally, however, the prevailing tint is imparted by earthy red iron-ore. Spheroidal or reniform stones of quartz and of compact red iron-ore,—at times as small as pease,— * “ The sandstone formation which bounds the mountain tract to the South “ towards the plains, assumes many different aspects here as it does in Europe; “upon the whole the resemblance is sufficiently striking to allow of our identifying “ it with the newer red or saliferous sandstone. It is either a hard red gravelly “ clay distinctly stratified, or the same clay enclosing rounded stones, or a mi- “ caceous sandstone, which in hardness varies from loose sand to a rock that will “ strike fire. This type is again modified by the admission of rounded pieces “ passing into sandstone conglomerate. * * * The sandstone is always micaceous “ in a high degree; it is most commonly of the ordinary colour, but sometimes “ it is found of a dark bluish-grey, in which case it seems to loose its appearance “ of a schistose structure, and becomes amorphous, breaking equally in every “ direction. This type is further remarkable for containing kernels of superior “ hardness to the base, which itself is more compact, and I might say clayey, “ than the ordinary sandstone. It also contains less mica. This grey type also “ passes into the conglomerate structure. * * * At Bhumowree it is seen in the “ river bed, dipping N.E., at an angle of about 30°; but it has here scarcely any “ developement. * * * At the Chilkein defile * * * it forms very extensive “ strata, chiefly of the red clay type. In the bed of the Cosillah, occasionally “ rounded stones are contained imbedded. * * * At Dhikoolee, the conglom- “ erate character is perfect, the basis being still the red clay, but sometimes “ indurated to a high degree. * * * At Chookoom * * * we find a greenish “ grey sandstone with mica dipping S.W.” Capt. Herbert Journal of the Asiatic Society , xii. N.S. pp. cxxxiii. cxxxiv Deposits of North-western India. 39 frequently as large'as eggs, — but generally about the size of acorns or of grapes, — are sparingly scattered through the other ingredients; sometimes, however, they are so numerous that,—cemented only by the other constituents, — they form, as one or the other mineral prevails, either a quartzose or a ferruginous con¬ glomerate. So closely indeed are some nodules of the ore packed, and so richly is the cement uniting them impregnated with it, that certain portions of the formation at Jharri* near Huldwanee, and at Loha Bahbur\ not far from Kaleedoongee assume rather a vein-like character. Seldom however are both quartz and iron-ore plentiful in the same neighbourhood ; nor are the conglomerated masses of either often very large. Approximately parallel to the mountain-chain of which they form the southern or south-western slope, the beds of sandstone generally bear about S.E. and N.W., and dip S.W.; although for short distances, in some parts of their course, they take an E. and W., and in others a N. and S. direction. But whatever the inclination of the sandstone-beds, the parallel masses of ferruginous conglomerate they include at Bejapoore £ near Bhamouree dip towards the N. The unusually open joints are faced with clay in the earthy—and with red iron-ochre in the metalliferous— parts of this formation. Whilst in the mountainous regions,—rich iron-ore occurs in large masses,—fuel is untaxed,—and the * Extracts from the Records of Government (Calcutta, 1855), p. 13. t Ibid, pp. 12, 46. % Ibid, pp. 12, 46, G 40 W. J. Henwood, on the Metalliferous climate is good throughout the year;—in the plain (Bhabur —or TuraeeJ , on the contrary, small nodules of ore—though the same in quality — are thinly sprinkled through the rock, — the farmer of Govern¬ ment revenue levies a tax # on the wood-cutter, and the climate drives even natives to their hills for half the year.f Although hitherto of but little avail, experiments, sanctioned by Government, are still in progress at Jham , Bejapoore , Loha Bhabur and Dechowree.\ The slight traces of ancient mining, and the re¬ mains of but a single furnace, amid the still flourishing woods of the Bhabur, attest however the preference of native workmen for the more abundant ore, and the untaxed, though scarcer, fuel, of the higher and healthier districts. (C.) Near Dol§ at the head of the Punaar valley, and * “ Table of Rates according to which Farmers of Jungle produce are authorized u to collect in Kumaon Bhabur — “ Per Cart load of Wood—depending on quality 4—6 annas (=6—9 pence) Charcoal...4 Bamboos.6 Heeds..6 Limestone...6 Burnt lime.12 ( 6 „ ) ( 9 ,. ) ( 9 „ ) ( 9 „ ) ( 18 „ )” Mr. Commissioner Batten, Official Reports on Kumaon , p. 216. f , ( - A -^ Mine. Ore. Charcoal. Bloom. Charcoal. Bar-iron. lbs. lbs. lbs. lbs. lbs. Simul-khet .. 100 .... 36-55 = 35-21 .... 35*16 = 8.79 Burrulgaon.. 100 .... 72*72 = 30*3 .... 31*81 = 909 These ores contain when pure, more than sixty per cent of metalf; but the most scrupulously selected portions of them, carefully freed from impurities, yield to the native smelter less than one-tenth of their weight in bar-iron. Each party working underground usually consists of two miners (Soanes) and four labourers (Coolies): the former open and timber the works; the latter stow all poor ore in unwrought holes, and draw that of better quality to the surface; where,—exercising a second scrutiny,—they reject every refractory ingredient, but carry all fusible matter to the furnace. Each miner’s complement of tools costs about (eight annas) one * Extracts from the Records of Government (Calcutta, 1855), p. 39. t Memoirs of the Geological Survey of Great Britain. Iron-ores. Part I. (1856), pp. 60-66. \ Deposits of North-western India . 59 shilling per month for repair, and consists of two picks, two hammers, several wedges (gads), and, occasionally a pointed bar, all made of iron; the labourers use only .hammers, and strips or bags of hide. A few brief intervals, devoted to the celebration of Pagan rites, alone vary the native workman’s constant toil of eight hours daily throughout the year the month may therefore average twenty eight working days. More than half the ore broken needs for its reduction a heat far greater than any native furnace ever attains : useless, therefore, to the smelter, all such is either left under¬ ground, or rejected when brought to the surface. The available portion,—varying with circumstances,— averages perhaps about (five maunds) 400 lbs. per day for each of the two miners in every working party.f When ready for smelting the ore is divided into five equal portions; of which the Farmer of Government Royalties. . .takes one ; „ Smelter. „ one; „ Charcoal burners... „ two; „ Miner and his two labourers (coolies) „ one. But the miner has still to share his part with his two labourers (coolies) ; who halve one moiety of it between them, whilst he takes the other. Even this suffers further reduction ; for about a quarter of every charge remains unfused in the furnace and is equally divided between the Farmer of Government Royalties and the Smelter. . * Extracts from the Records of Government (Calcutta, 1835), p. 29. f Ibid, pp. 29, 30. 60 W. J. Henwood, on the Metalliferous During the miner’s working month of twenty eight days, he obtains on an average, 400 lbs. of cleaned ore daily; in which his share—a moiety of one-fifth—is 1,120 lbs.; and this—at nine per cent:—the general yield of native furnaces in Kotelar and Khetsaree— affords about 100 lbs. of metal. The ordinary price of home-smelted bar-iron in Kumaon and Gurhwal is ten rupees for fifty six seers , or one Pound sterling per hundred-weight; at which rate the miner’s gross income amounts to about (nine rupees) eighteen shillings per month. But the ordinary working party, of two (Soanes) miners and four (Coolies) labourers, whilst smelting their portion of the ore,—which they do without sub-dividing it,—provide the smelter and his assistants with 20 lbs. # of meal daily ; this costs—even in the cheapest districts,f at least (one rupee) two shillings per month to each (Soane) miner for his one- fourth part. This with another (eight annas) shilling for repair of tools, deducted from the value of his iron, reduces the miner’s net earnings to about (seven rupees and a half) fifteen shillings per month, or barely sixpence half-penny a day. The miner’s skill, the nature of his ore, and the price of iron, all—of course—- affect, more or less, the amount of his gettings; but,— though sometimes as low as five pence;—they seldom exceed seven pence per dayj. * The chief Smelter takes 4 lbs., his sledge*man and four women who work the (air-bags) bellows each 3 l-5th lbs. f“In the western midland pergunnahs of Gerhwal * * * wheat is selling “ at two maunds (160 lbs.) the rupee.” — Mr. Commissioner Traill, Asiatic Researches , xvn. Official Reports on Kumaon , p. 98. % Extracts from the Records of Government (Calcutta, 1855), p. 30. Deposits of North-western India. 61 Entitled to but half as much ore,—supplying the smelter with only half as much meal,—as the miner,—■ and providing no tools, the labourer’s usual earnings are about (four rupees and a half) nine shillings a month or scarcely four pence per day : occasionally, however, he may assist either the miner or the smelter, and thus obtain,—at most—another penny. The wages of ordinary labourers is still smaller.* As the miner and his two labourers realize, between them, about (eighteen rupees) thirty six shillings per month, by selling the iron (200 lbs.) obtained from their shares in the 11,200 lbs. of ore they break (dressJ, prepare, and carry to the furnace; every (21 cwts.) ton of such ore delivered at the smelting-house stands them in about seven shillings and seven pence. More than half the ore extracted is, however, too refractory for native treatment, although comparatively little of it is beyond the skill of European smelters; ordinary blast-furnaces might therefore be supplied with ore, of but slightly inferior quality to that now selected for use, at from three shillings to three shillings and six¬ pence per ton.f Throughout Kumaon and Gurhwal the estimated * “ Two annas ” (three-pence) “per diem is the usual rate of hire, but to en- “ sure a constant supply of labour it would probably be found necessary to raise “ it to 3 or 4 annas.”— Mr. Commissioner Lushington, Journal of the Asiatic Society, xn. n.s. p. 470. Extracts from the Records of Government (Calcutta, 1855), p. 30. “ Even the modest sum of (sixty-six rupees) Six Pounds and twelve shillings " exceeds the annual gains of the common Hindoo labourer.” The Times , 24th October, 1859. f Extracts from the Records of Government (Calcutta, 1835), p. 30. 62 W. J. Hen wood, on the Metalliferous price of charcoal delivered at the furnace from forests within four miles, is about (three annas) four pence half-penny for (30 seers) 60 lbs., # or fourteen shillings and eight pence per ton.f The Mining Royalties collected in these Provinces by the Goorkha Government during 1812, were—from Kumaon, 2,400 Furruckabad rupees, or 1,800 Company's rupees. Gurhwal, 2,401 „ „ l,800f „ „ 4,8011 „ „ 3,600£§ „ British dominion was established during 1815; and the revenue—in one year as low as 4,460 || rupees, and in another as high as 5,417,^[—averaged from that period to 1838 about 5,217 rupees; viz.,—from Copper. Iron. Total. Kumaon .... 1,000 _ 1,905 .... 2,905 Gurhwal .... 2,086 .... 226 .... 2,312 3,086 2,131 5,217 * * * § ** * Extracts from the Records of Government (Calcutta, 1835), p. 33. t Information was obtained from many parties relative to the division of their ore, and the amounts of their earnings ; but from no one so thoroughly conver¬ sant with every particular of native mining economy as Kishna Pudhan of Par- tubura (Collector of Revenue. Official Reports on Kumaon , p. 464), who farmed the Government Royalty of iron mines during 1854-5. J Mr. Commissioner Traill, Official Reports on Kumaon. Appendix. Statement B. § Mr. Commissioner Lushington, Journalof the Asiatic Society, xn. n.s. p. 457, Note. Official Reports on Kumaon, p. 369, Note. || In 1822-3 the Cess on Copper mines was. 3,360 rupees. ,, >> Iron ,, ..1,100 ,, Mr. Com. Traill, Asiatic Researches, xvi. Official Reports on Kumaon, p. 51 . IT Mr. Commissioner Lushington, Journal of the Asiatic Society, xn., N.S., p. 457, Note. Official Reports on Kumaon, p. 369, Note. ** Ibid. Deposits of North-western India. 63 In 1855 the amount of Royalty had materially declined: for all works at Rai ,* * * § BellarGoronf\ and Tarag-ke-Tal% having been abandoned; whilst Dhunpoore , ^Pokree ||, AZ Ayur,f Kurrye and Seera ** were languidly, and inefficiently wrought; the public income from copper-mines fell, during that year, short of.*. 1,900 rupees. The farmer of Government dues from iron-mines paid, at the same time, a rent of. 1,950 „ Although therefore the mining revenue had increased from about three hundred and sixty before,—to above five hundred Pounds a year after—the British con¬ quest, it has again dwindled, to little more than its previous amount. * “ At present the revenue derived from these mines is only 101 rupees per “ annum.— Mr. Commissioner Batten, Official Reports on Kumaon, p. 274. f Neither of these mines is mentioned in any Official Report on Kumaon. J “ There is a small copper-mine recently opened,— jumma” (annual rent) “ 35 rupees.”— Mr. Com. Batten, Official Reports on Kumaon, p. 317, Note. § “ Twenty-one villages, large and small, have always been attached to the “ Dhunpoore mines; and it has been found impracticable to separate the lease “ of the villages from that of the mines. * * * Out of the total revenue of 1,901 “ rupees paid by the farmer of Government, I found that he only collected 266 “ rupees from the villages.” Ibid, p. 154. || “ From the time of the Ghoorkha conquest (1803) up to the year 1838 the “ produce of the Pokree mines had become more and more scanty, and when “ (towards the close of the above year) these mines were handed over to Mr. ‘‘ Wilkin, the actual revenue at which they were rated in the public accounts “ amounted to 100 rupees per annum, and this small sum was eventually remitted “ for that year, owing to the poverty and utter inability of the farmer to pay “ the Government demand.”— Mr. Commissioner Lushington, Journal of the Asiatic Society, xn. n.s. p. 457. Official Reports on Kumaon, p. 369. IT “ The copper mines in Khurhai at present yield 15 rupees to the state, and u they are now being abandoned by their lessees. * * * The nature of the soil “ in which the cupriferous deposits occur, renders the efforts at working the mines “ a constantly recurring and nugatory labour, and the results the most puny and “contemptible.”— Mr. Commissioner Batten, Official Reports on Kuynaon. p.313. ** “ The mine at present * * * yields hardly any proceeds. The last farmer “ had great difficulty in paying the small jumma ” (rent) “ of 85 rupees per “ annum.”— Ibid, p. 281. The Royalty received by Government from Seera during 1855 amounted to 35 rupees. 64 W. J. Hen wood, on certain On certain deposits of Iron-ore in Bengal. Many attempts to find iron-ore in the rich and extensive coal formations of Bengal, were made, as well by Government as by commercial associations and individuals, long before the extension of railway communication through India had increased the con¬ sumption of iron to its present rate. (a.) On the picturesque southern slope of the Rajmahal range,* quartzose gneiss is overlaid by com¬ pact quartz-rock at Fitcooree and this is succeeded at Jherria by siliceous sandstone: which—grey in some places but brown in others—occasionally exhibits traces of carbonaceous matter, apparently of vegetable origin. The grey varieties contain mica; the brown probably take their hue from imbedded nodules of clay iron-stone, oxydulated iron-ore, and earthy brown iron- ore mixed with quartz. Generally these kernels are smaller than pease, though a few of them are as large as eggs; most of the ore occurs, however, in masses about half an inch in diameter. Slightly screened by a meager vegetation,^: the rock yields readily to dis- * Bishop Heber, Narrative of a Journey through the Upper Provinces of India (Edit. 1849), i. p. 119. t M The country round Fitcoree is rather pretty, the hills covered with bamboo “ and brushwood, and * * * rising rather suddenly from the elevated plains. u * * * Great crumbling masses of quartz protruded through the soil." Dr. J. Dalton Hooker, Himalayan Journals (Edit. 1854), i.pp. 13, 14* J “ The vegetation of this part of the country is very poor, no good-sized trees “ are to be seen, all is a low stunted jungle.”— Ibid, p. 12. Deposits of Iron-ore in Bengal . 65 integrating atmospheric influences ; its lighter siliceous particles are quickly dispersed; but the ferruginous ingredients they once enclosed, still thinly sprinkle the surface. Masses of quartzose breccia, and of amygdaloidal trap* mixed with earthy manganese, appear above the sandstone at intervals; and, overlying these, a bed of bituminous coal of excellent quality, from seven to twenty feet in thickness, is traced at the surface for more than half a mile; but, though within two hundred miles of Calcutta, it is wrought only to supply the neighbourhood.')' A few small heaps of iron-slag show that the ore has not been unnoticed; but when the experiment which afforded them was made, or what result was obtained, is alike unknown to the (Rajah) proprietor and his attendants: although a tradition yet remains that coal was employed in it. ( b .) For some distance on either side of the coal formation,^; a while unsuccessfully wrought at Paunch- * Dr. J. Dalton Hooker, Himalayan Journals (Edit. 1854), i. p. 13. 1 t Mr. Homfray, Journal of the Asiatic Society, xi. n.s. p. 739. Mr. Williams, Geological Report on Damoodah Valley (Calcutta, 1850), p. 83. X Ibid, p. 67. Dr. Me. Lelland, Reports of the Geological Survey of India, Calcutta, 1850. “ The coal crops out of the surface; but the shafts worked are sunk through “ thick beds of alluvium. The age of these coal fields is quite unknown, and I “ regret to say that my examination of their fossil plants throws no material light “ on the subject. Upwards of thirty species of fossil plants have been procured “ from them.”— Dr, J. Dalton Hooker, Himalayan Journals ( 1854), i. p. 7. Professor Oldham, Edinburg New Philosophical Journal, n. N.s. 210. Messrs. Hislop and Hunter, Quarterly Journal of the Geological Society of London, xi. p. 377. 66 W. J. Henwood, on certain maulee, about a mile north-west of Taldanga on the Barrukkar, the joints,—unusually numerous, short, and broad, in certain parts of the brown siliceous sand¬ stone,—are lined with many thin laminae of clay iron¬ stone, which thus impress a brecciated character on the mass. # Spheroidal nodules,—each wholly or in great measure made up of many concentric bands,—of the same ore, also abound in the neighbourhood; but especially beneath the coal, in a bed of shale, from four to six inches in thickness. This was formerly wrought by the natives, as well from shallow shafts as in open-cuttings, throughout an area of perhaps seven acres; and the ore, so obtained, was smelted with charcoal. South of the Barrukkarf the sandstones and coal of Paunchmaulee are succeeded by a large body of shale; through which clay iron-stone is disposed in small groups of irregular beds; but these are seldom either as much as three inches in thickness,J or more than ten feet in length and depth. (c.) Many parts of the productive coal district near Raneegunge, are covered with coarse gravel; composed, * Between Churra and Kala-panee in the Himalaya “ the sandstone * * * is “ curiously divided into parallelograms, like hollow bricks, enclosing irregularly “ shaped nodules. I have seen similar bricks in the sandstones of the coal- “ districts .of Yorkshire : they are * * * probably due to some very obscure “ crystalline action analogous to jointing and cleavage.”-— Dr. J. Dalton Hooker, Himalayan Journals (1854), n. p. 285, f Mr. Williams, Geological Report on the Damoodah Valley , p. 67. J Professor Oldham, Report of the examination of the districts producing iron- ore in the DamoodaliValley and Beerbhoom (Calcutta 1853), p. 4. Deposits of Iron-ore in Bengal. 67 in great maasure, of brown siliceous sandstone, # but mixed, in some places, with small nodules of clay iron¬ stone, f (i d .) A bed of clay iron-stone,—ranging nearly east and west, and dipping with the surface, about 8° south,— is traced, at intervals, for perhaps a furlong on the ridge and twice that distance on the side of Akysa, a hill some eight miles north-east of Raneegunge.J At its outcrop the ore is about a foot in thickness; and,— occasionally quartzose,—is generally of good quality ; towards the south, however, it declines as well in size as in value: and at the bottom of the slope is—though mixed with siliceous and other foreign substances,— only six inches thick. ( e .) Although the rock for some distance south of Akysa is covered by a thin layer of sandy soil, it reappears in the northern bank of a brook at Barrul Cajoor; not however in one broad bed, as before; but, —interlying a buff-coloured siliceous sandstone,—in several small ones; which within a few fathoms space unite, divide, vary in quality, dwindle, assimilate to the rock, die, and re-appear. A few heaps of slag only remain to show that attempts at iron-smelting were formerly made in the neighbour¬ hood. * Mr. Homfray, Journal of the Asiatic Society , xi. n.s. (1842), p. 743. + Professor Oldham, Iteport of the examination af the districts producing iron- ore in the Damoodah Valley and Beerbhoom. Major Baker, and Professor Oldham, Extracts from the Records of Government , No. 964 (Calcutta, 1853), pp. 1—8. % Mr. Homfray, Journal of the Asiatic Society, xi. N.s. (1842), p. 745. 68 W. J. Henwood, on the The sandstone containing small beds of clay iron¬ stone is succeeded by a seam of coal, which has been opened in several places; from this, however, attention has been withdrawn, by the richer and more accessible deposits of Raneegunge. # * Excellent as the Bengal coal is for general purposes, experienced persons have failed in every attempt to obtain serviceable coke from it: the East Indian Railway Company therefore work their locomotives between (Howrah) Calcutta and the coal-mines with coke made of British coal (1855). Mining District of Chanarcillo in Chili . 69 ‘v,.' . . < V ( The Mining District of Chanarcillo in Chili, about fifty miles inland, is approached from the Pacific coast by a railway between Caldera, Copiapo— the capital of Atacama,— and Pabellon; and thence by a good, though circuitous, road across the moun¬ tains. The isolated mountain of Chanarcillo, rises nearly four thousand feet above the sea and more than two thousand higher than the undulating plain surrounding and separating it from the lower Andes. Three strata of limestone and two of quartz, mixed with hornblende, bearing some 30° W. of N. and E. of S., # alternate in its abrupt north-eastern escarpment; but dipping in the same way as—though less rapidly than—the surface, the upper two of them only crop out in its steep south¬ western slope. The perfect uniformity of this declivity is varied by the Morro de San Jose and Morro de Dolores (Pl. I.), small conical hills, formed of successively smaller discs of rock, each traced for its entire circum¬ ference. These answer as well in composition and appearance as in situation and slope, to certain beds in the mountain, with which they were, perhaps, originally united. When silver was found at Descubridora (Pl. I.), in 183If or 1832,f by Juan Godoi a muleteer whilst in * In June, 1857, Mr. E. Price Waring ascertained that the magnetic variation at Chanarcillo was 13° 50' E. t Mr. Domeyko, Annales des Mines , 4me. Serie, xx. 1846, p. 453. J Colonel Lloyd, Report to the Foreign Office (Woodfall, London, 1857), p. 7* 70 W. J. Hen wood, on the Mining search of a lost animal, the district was overspread by a thicket of the Chahar ,—a species of dwarf plum-tree, —and from that circumstance, was named Chanarcillo. A large mining population, attracted by the discovery, quickly stripped the surface of its wood ; so that neither tree, shrub, field, garden, nor even an occasional wild- flower, now relieves the brown and dreary monotony, the uniform and frightful barrenness, of this rich but horrible desert. Although the bed of every valley and glen is overlaid by a thick bed of shingle, pebbles, and gravel, deeply scored with ruts and other indications that the country was formerly well watered : there is neither a single spring in the district, nor is one streamlet now visible from the bleak summit of Chanarcillo; except—perhaps twice or thrice in the year—when an occasional shower may for a few hours supply each ravine with a scantily trickling rill; these are however quickly absorbed by the thirsty soil. No water has even been drawn to the surface of any mine in the district; a little moisture, however,— derived, perhaps, from ascending vapour,—exudes from some of the rocks and veins, but it is immediately ab¬ sorbed by other portions of the neighbouring strata. Amongst the many mines opened at different eleva¬ tions in Chanarcillo three only have been wrought deeper than the surrounding plain ; and these,—though more than two hundred and sixty fathoms below the surface,—are still far above the sea. (A.) (a.) From the Manto de Ossa , at its summit, to San Francisco viejo , far down its slope, the mountain District of Chaharcillo in Chili. 71 is composed of limestone: which is more than one hundred and twenty fathoms thick in the north east¬ ern outcrop; but,—from the upper inclining more rapidly than the lower face (PL II. )—presents a mere edge on the south-west. Between the Manto de Ossa and San Francisco viejo the various beds and the lower side of this forma¬ tion maintain, on the whole, a tolerably regular inclination—of about 5°—towards the south-west. At Colorada, however, an irregular boss some ninety fathoms in diameter and thirty in thickness (Pl. II., K.) forms its nether portion, and thus extends the first limestone to within a few feet of the second. This protuberance is, like the little hills at San Jose and Dolores on the surface, constituted of many somewhat elliptical layers; which,—narrowest at greatest depths, and vice versa — closely resemble, as well in bedding as in composition, the mass of limestone they adjoin. Although many cross-veins heave the lodes in Chan¬ arcillo, only one of them displaces the rocks also. At San Francisco viejo the Colorada lode, bearing 38° E. of N. & W. of S., and dipping W. 65°-74° ; the Waring lode , bearing 38° E. of N. & W. of S., and dipping W. 64°-78 3 ; and the Dolores Primera lode , bearing 38° E. of N. & W. of S., and dipping W. 70°; are all heaved about 9 fms. towards the left-hand and greater angle* (PI. I.), by the Flucan , which bears 30° W. of N. & E. of S., & dips N.E. 70°; and on one—(its north-eastern or upper)-side ( hanging wall), the strata are twenty-one fathoms below their * Cornwall Geol. Trans., v. pp. 5, G. L I 72 W. J. Henwood, on the Mining counterparts on (its south-western or lower side) the other* (foot-wall) (Pl. II.). South-west of the Flucan they dip, however, so much more rapidly than on the north-east, that their outcrop occurs at about the same level it would have maintained, had there been no displacement. (b.) The first hornblendic formation separates the first from the second limestone; its upper and lower faces are therefore respectively parallel to the nether side of the one, and the surface of the other. As the former inclines about 5°, aud the latter nearly 8°; the rock between them increases in thickness, from twenty- four fathoms at its north-eastern outcrop, to fifty-four at the Flucan in San Francisco viejo ,—four hundred and eighty fathoms distant on its slope towards the south-west. Partaking, however, every irregularity in the contour of both bounding strata, it is sixty-five fathoms thick at Fesempeho , but scarcely five between a deep depression of the upper and an opposite elevation of the lower limestone in Colorada. It suffers in com¬ mon with the other strata, a vertical displacement of twenty-one fathoms at San Francisco viejo; and dips, like them, much more rapidly to the south-west than on the north-east of the Flucan. (Pl. II. N,0 ; U,V.) (c.) The first hornblendic formation is separated from the second, by a deposit of limestone, more highly * f< The ‘ slip ’ or plane of dislocation hades, dips, underlays, or is inclined to “ the vertical so as to pass under the depressed portion of the strata which are “ displaced.”— Professor Phillips, Illustrations of the Geology of Yorkshire, Part ii. p. 111. Pl. xxiv. Fig. 16. District of Chanarcillo in Chili . 73 inclined than the first (a.), and marked on both faces, but especially on the upper, by undulations larger and more numerous than—with a single exception (PL II., K.)—those in any other part of the series. A few por¬ tions of the surface have a north-easterly dip, but its general inclination is about 8° towards the south-west. The lower face, less deeply inflected, slopes more rapidly—perhaps 10°—the same way. Its thickness thus increases, from seven fathoms, beneath the Manto de Ossa , to nearly thirty, at the Flucan in San Francisco viejo. ( d .) A second formation of quartz and hornblende,— the largest member of this series,—divides the second (c.) from the third limestone (e.). Conforming in position to the rocks they adjoin,—its upper and nether faces dip respectively nearly 10° and about 4° south-west; and thus,—unlike the strata above,—it thins from one hundred and thirty-five fathoms, at its intersection towards one extremity of the district, to less than seventy at its displacement near the other. About the middle of this formation a few beds of argillo-siliceous limestone (hydraulic lime), together less than two fathoms in thickness, maintain an approx¬ imate parallelism to the second limestone (c.) through¬ out Chanarcillo. (e.) A third limestone formation,—unrecognized elsewhere,—is laid open in the lowest works of the deepest mines; but, as it has never been pierced, its thickness is unknown. Its surface dips about 4° towards the south-west; and—in common with the shallower 74 W. J. Henwood, on the Mining strata (a. b. c. d.) is displaced at the Flucan in San Francisco viejo . (B.) Differences in structure, composition, and colour, characterize various beds in each of the five formations. As Chanarcillo is now so dry and so destitute of vegetation, its rocks yield to disintegration but slowly; their structure is therefore well displayed at the surface. The first limestone (a.) is intersected by four series of joints, which bear j- (1).. 15°—30° E. of N. and W. of S.: 1(2).. 15°—30° S. of E. and N. of W.: f (3). .20—30° W. of N. and E. of S.; (4). .30°—45° N. of E. and S. of W. A separate and distinct—approximately rectangular— structure is thus developed within the mass by each of the two pairs respectively. As however they interlace diagonally, the quadrangles articulated by one pair of joints, are subdivided into triangles,* by the other. * “ Beside the joints which approach to rectangularity, there are also others “ which have an intermediate direction, and divide the blocks diagonally into District of Chanarcillo in Chili . 75 But as every joint suffers occasional interruptions* and deflections,f all the four series are seldom, if ever, alike pronounced in the same spot. The first and second, traced at short intervals throughout the district, are thus interlaid by the third only at Colorada near the middle of Chanarcillo, but by the fourth alone at Descubridora and the Guias de Carvallo on either side. Although joints are in general merely closed seams, those in the crest of this mountain are so wide and so numerous, that,—filled with earthyj and stony debris of the adjoining rock,—they impress to some extent a fragmentary character on the mass. (2.) The bed known in different mines as the Manto de Ossa , Manto de Mandiola , Manto de los Cobos, and Manto de los Bolados is usually from four to five, but occasionally as much as eighteen or twenty feet thick. The structure is generally cellular or vesicular; “ triangular masses, which in some situations seem to he rather more evident than “ the rhombs.”— Cornwall Geological Transactions , v. p. 170. * “ Occasionally a * * * joint * * * has only been found by the breaking of “ the rock in working.” Me. Enys, London and Edinburgh Phil. Mag. II. (1833), p. 322. f “ But though the joints often preserve a tolerable regularity for some distance (t they have frequent and considerable flexures, on the lines both of direction and “ of dip; the opposite bounding planes of the jointed masses are therefore seldom “ quite parallel.”— Cornwall Geological Transactions, y. p. 170. Ante, p. 13. % Mr. Domeyko’s analysis of this earthy matter gave Carbonate of lime. ,335 Carbonate of magnesia. ,052 Alumina and oxide of iron.. ,101 Silica . ,170 Insoluble matter. ,270 Water and loss. ,072 1,000 Annales des Mines , 4me Serie, ix. p. 437. 76 W. J. Henwood, on the Mining and the joints—especially of the first and second series— are well developed ; but they are fewer and narrower in this bed than in that which overlies it. The rock in different parts is either of a dark blue, brown, or buff*colour, but white calcareous spar occurs at intervals, as well in small veins and isolated masses, as facing or filling its joints. Throughout this bed, especially where calcareous spar and earthy iron-ore abound, for some distance on either side of the Candelaria , Colorada, and Descubridora* lodes the rock is sprinkled, its laminae are interlaid, and its joints are invested or filled, with granules, filigrees, leaves, plates, and veins of native silver, mixed with the sulphuret, the chloride, and—less frequently—the chloro-bromidef of silver. In many such parts of the Manto this impregnation has been so general and so rich that the workmen have left only a few slender pillars of it to support the roof; and these are mostly pierced and scored in pursuit of rich veins and fibres. On every side of the caverns^ thus opened, galleries, extended on lines of ore nearly coincident with the joints, form as they interlace an almost inextricable labyrinth. Silver and silver-ore are thus scattered through lime¬ stone in this part of Chanarcillo, in the same manner * One mass of native silver and silver-ore obtained from this lode was so large, that it was mounted and long used at the mine as a card-table. t Mr. Domeyko, Annales des Mines , 4me Serie, ix. p. 453. Colonel Lloyd, Report to the Foreign Office, on the Mines of Copiapo (London, 1857), P- 13. X In such an opening on another formation at the Gtiicis de Carvallo a horse whim has been set up and is worked by lamp-light. District of Chaharcillo in Chili . 77 as gold is dispersed through Jacotinga* * * § ** * * §§ in Brazil; native copper through certain trap-rocks near Lake Superior; f tin-ore through slate at Fatworh , J and through granite at Carclaze , § Raggy-rowal, || and Balleswidden in Cornwall, at Geyer in Saxony, and Zinnwald ## in Bohemia; and the carbonate of copper through sandstone at West Felton in Shropshire, Alderley Edge ^ in Cheshire, and Huidobro in Old Castile.§§ (3.) Many small cavities, incrusted with the cliloro- bromide of silver and filled with calcareous clay, occur in a bed of ferruginous limestone, a few inches thick, which crops out at Colorada some thirty fathoms below the Manto. (4.) A second thin bed of cellular limestone, even more ferruginous and clayey than the first, appears about fifty-five fathoms beneath it; and, as it intercepts the scanty portions of rare shower^ which, absorbed by the * “ Micaceous iron Schist.”— Gardner, Travels in the Interior of Brazil, p. 493. Fostea. f Whitney, Metallic wealth of the United States, pp. 270, 287. X Cornwall Geological Transactions, v. p. 120. § M. Jars, Voyages M6tallurgiques (1765), hi. p. 190. Professor Sedgwick, Cambridge Philosophical Transactions, I. p. 108 ; and (Address to the Geological Society, 18th February, 1831), Proceedings of the Geological Society, i. p. 283, Philosophical Magazine and Annals, ix. (1831), p. 284. M. M. von Oeynhausen and von Dechen, Philosophical Magazine and Annals , v. (1829), pp. 241-2. Dr. Boase, Cornwall Geological Transactions , iv. pp. 238-9. Ibid, v. p. 120. || Cornwall Geological Transactions, v. pp. 53, 235. H Ibid , pp. 15, 235. ** Mr. Hawkins, Cornwall Geological Transactions , n. pp. 33, 43. tf Murchison, Silurian System , pp. 39, 297. Postea. Murchison, Silurian System, pp. 39, 297. Mr. Higgs, Cormcall Geological Transactions, yn. §§ Postea. 78 W. J. Henwood, on the Mining surface, are not dissipated in shallow galleries, is, there¬ fore, called the Manto de Agua. Alternations of crystalline, greyish-buff, with homo¬ geneous, compact passing occasionally into slightly lamellar, # dark-blue limestone, make up the rest of this formation. (c.) The second limestone exhibits similar alternations of buff coloured with blue, and crystalline with compact rocks; but contains neither fragmentary nor metal¬ liferous beds. The presence of silica and aluminaf makes hydraulic limej common to both formations. ( d —1.) A bed of siliceous limestone about nine feet in thickness, divides the second hornblendic formation parallel to its surface into nearly equal parts. (e.) As deep as eighteen or twenty fathoms the third limestone is greyish blue and semi-crystalline; there, however, it suddenly assumes and thenceforward main- * “ The various kinds of structure so frequently pass into each other in the “ same mass, that it is oftentimes very difficult to observe where the one begins * and the other ends. When the rock has a compact texture, but more par- “ ticularly if it be crystalline, it most commonly exhibits a massive structure ; “ and as it gradually becomes more and more fine-grained and homogeneous, it “ generally acquires a proportionate degree of fissility.” Dr. Boase, Primary Geology , p. 104. f “ La roche la plus commune de cet etage est un calcaire argileux contenant “ environ 40 p. 100 de residu inattaquable par les acides, et ne renfermant que “ quelques traces de magnesie. M. Domeyko, Annales des Mines 4me Serie, ix. p. 438. + «< Whe^i limestones contain considerable portions of silica and alumina, they <( form what has been termed of late years hydraulic lime , and the mortars “ made with them are called hydraulic mortars, of these, Parker’s cement * * * * “ will set, as it is termed, or become solid in a quarter of an hour, either in air “ or underwater .”—Penny Cyclopaedia (Article Mortar), xv.p. 420. District of Chanarcillo in Chili . 79 tains a bluish-black hue and homogeneous structure. Its joints, meanwhile, are lined with amianthus. (1.) About four fathoms beneath the surface of this formation the Manto de Cachi, a bed of calcareous spar no more than three inches thick adjoining the lodes and scarcely an inch elsewhere, is traced throughout the district. The limestone strata are destitute of organic remains at Chanarcillo, but they afford them in the neighbour¬ hood.* ( h.d .) The three strata of limestone, alternate with two groups composed in great measure of felspar, quartz, and hornblende. In both these much white felspar often imperfectly but sometimes regularly crystallized, and dark green hornblende in small groups of prismatic crystals, are scattered through a basis of quartz and felspar ; which, mostly mixed with hornblende, is generally green. (2.) Acicular crystals of hornblende thinly interlace subordinate beds of quartz. (3.) Greenstone, perhaps rather finer in grain below than above,t makes up the remainder of both groups. Grains of iron pyrites are found at intervals, and particles of copper pyrites less frequently: calcareous spar, either as an ingredient of the rock or in small * “ Je n’ai pas trouve de debris organiques dans toute la partie de la montagne “ qui renferme lesfilons metalliferes, quoiqu’on en trouve, comme je viens de “ dire, autant sur le chemin de l’est, pres de Molle, que sur le chemin du nord- “ ouest, aux environs d’Ingenio.” M. Domevko, Annales des Mines , 4me. Serie, ix. p. 435. t Ibid, p. 437. M 80 W. J. Henwood, on the Mining irregular veins, occurs sparingly throughout the series but epidote, similarly dispersed, appears in the lower beds only. The presence of asbestus in minute flakes gives some portions a foliated character,')' whilst in both groups others are massive; a crystalline structure is, however, common to all. A few of the numerous joints^ present mere unctuous faces; but most of them are filled with calcareous spar, mountain-cork, mountain-leather, or amianthus. No intermixture of ingredients takes place, no veins extend from one rock into the other, at any contact of the calcareous and hornblendic formations; every change of series is, on the contrary, sharply defined and immediate. At Colorada all the strata are alike traversed from S.E. to N.W. by two parallel dykes, about four or five fathoms apart, dipping N.E.; one three or four, the other six or eight feet wide. Their chief ingredients,— felspar and hornblende,— are often porphyritic, dis¬ integrated, and soft, in the calcareous series; but,— mixed with quartz,—are fine-grained and hard when intersecting hornblendic formations. (c.) The most productive veins in Chanarcillo are— * “ On a trouve cette roche composee de “ Carbonate de chaux. *076 ,, de magnesie. *034 “ Partie attaquable par les acides *316 tenant *08 de silice soluble dans la potasse. “ Partie inattaquable. -572 •998.” M. Domeyko, Annales des Mines, 4me. Serie, ix. p. 439. f Ibid, p. 440. X Ibid, p. 437. District of Chaharcillo in Chili. 81 Direction. Dip. the Descubridora lode .18° E. of N, & W. of S. ... W. •• Guanaca lode . N.E. & SW. N.W. •• Guiasde Descubridora branches 18° E. of N. & W. of S. ... W. *• Waring lode . 38° E. of N. & W. of S. ... N.W. •• Colorada lode . 38° E. of N. & W. of S. ... N.W. •• Caunter lode .30° W. of N. & E. of S. ... N.E. *• Dolores Primera f or Loreto lode 38° E. of N. & W. of S. ... N.W. •• Guias de Dolores Tercera) _ . . branches . j ^ N. ^ ••• N.W. •• Candelaria lode . 20° N. of E. & S.of W. ... W.ofN. •• Bolaco lode . 20° W. of N. & E. of S. ... W. •• Guias de Carvallo branches .... 20° E. of N. & W. of S. ... W. Innumerable small branches spread from all, especial¬ ly from the Candelaria , Colorada , and Descubridora , the largest and richest lodes in the district. Some of these connect neighbouring veins ; but generally they dwindle and disappear, as well vertically as horizontally, within very short distances. (1.) The directions of productive lodes are, perhaps, more diversified in this than in any other mining district; for they yield similar ores, whether parallel or transverse to the (flucans) veins which are composed of clay only. (2.) The strata slope gently (4°—10°) to the south¬ west, but the lodes incline much more rapidly (64°—78°) towards points which—from the relations between dip and direction—are as various as their bearings; yet, with one exception only, are always west of the meridian. The passage of lodes from one rock to another is, when uninfluenced by other circumstances, nowhere accompanied by remarkable changes of dip; save 82 W. J. Henwood, on the Mining between the Manto de Ossa and the limestone imme¬ diately beneath. There however the lodes do not directly enter one formation on leaving the other,—as elsewhere they do;—but, conforming awhile to the slope (10°—12° south-west) at their junction, pass for some way between them. Yet this coincidence is not of the same extent in every case; for after maintaining it,—the Candelaria (d.d\ Fig.l.) for about fourteen fathoms and a half,—the Colorado (a. a.) and Waring (b. b' .) for nearly eighteen fathoms and a half each,— and other lodes (c. c'.) for different distances, they all at length resume their normal inclinations (64°—78°). Fig. 7. (Transverse Section.) Scale 40 fathoms to the inch. a. a’. Colorada lode. b. b'. Waring’s lode. c. c'. c. c". Gidas de Descubridora. d. d'. Candelaria lode. As the lower sides (foot-walls) are distended and more erect when lodes improve in quality,* they thus * “ It is generally observed in the variations of the underlay or dip, that those “ parts of lodes are richest which are nearest to perpendicular.” Mr. Thomas, Report on a Survey of the Mining district from 'Chacewater to Camborne (1819), p. 20. “ It is a remarkable fact that in every lode , whether it yields tin, copper, or “ lead ores, the portions which are the most perpendicular are always the most “ productive. This perpendicularity invariably takes place by an alteration in District of Chaharcillo in Chili . 83 become at the same time larger, richer, and more highly inclined. (3.) Neither the dip nor the size of their poorer parts seems however to have much, if any, relation to the nature of the rocks they adjoin. Although considerable portions of the Colorada and Waring 1 s lodes maintain their characteristic breadths; this—the general fact elsewhere* *—is an exceptional one in Chaharcillo; where—on the contrary—differences in width are great, frequent, and sometimes sudden. The lodes are, however, largest and richest where they unite with minute veins, oblique both in direction and dip (cruceros); f which—elsewhere mere joints— widen only as they approach the lodes , when in the thick-bedded dark blue limestone.^ The Candelaria lode (Dig. 8. c. c.) is seldom more than six inches wide where it crosses the hornblendic dykes (a. a .' a. a.')§ of Colorada; but, though uniting with no other vein, it enlarges at the upper side (hanging-wall) to twelve or fifteen feet, immediately “ the inclination of the lower or foot-wall of the lode, which becomes more vertical “ (bellying out) ; whilst the opposite, or hanging-wall may continue on the line “ of its original dip: this change frequently produces, at one and the same time, “ a more perpendicular appearance, and an enlargement of size in the lode” Cornwall Geological Transactions, v. p. 231. * “ Every lode is generally characterized by a prevailing size, which, however, a may now and then fluctuate greatly, though, for the most part, it does so within “ moderate limits.”— Cornwall Geological Transactions, v. p. 241. t “ On appelle, au Chili, croiseur (crucero) tout filon secondarie qui s’unit au “ filon principal, formant avec cellui-ci un angle quelconque.” M. Domeyko, Annales des Mines, 4me. Serie, ix. p. 446. J Ante, p. 14. § Ante, p. 80. N 84 W. J. Henwood, on the Mining on entering the adjoining limestone. The Colorado lode ( b . //.) however traverses both rocks with but little change of size. Fig. 8. Plan a Scale 40 fathoms to the inch. a. a. a. a. Dykes. b. b'. Cobrada lode. c. c . Candelaria lode. The wider parts of lodes rarely consist of veinstone only, but enclose also blocks of the adjoining (country), and thus assume abrecciated structure.* Their widest portions often (take Horse) split;')' but such separate veins are seldom rich. On passing from one rock to another differing from it merely in hardness, the lodes often divide also into branches; which in the softer beds are generally less inclined, larger, and richer, but in the harder are flatter, smaller, and poorer than the lodes are when entire. (Table III.) (4.) Where no joint separates the lodes from the rocks, the transition between them is so gradual, that the changes in their mineral character are scarcely perceptible.^; * Cornwall Geological Transactions , 'v. pp. 210,213, 229. f Ibid, pp. 213, 231. J Dr. Boase, Primary Geology, p. 179. Cormoall Geol. Trans, v. pp. 184,186. District of Chanarcillo in Chili 85 Where, however, the lodes differ much in structure and composition from the rocks adjoining them, they are often bounded on either side by the smooth (walls) faces of joints,* which—subject to, each its peculiar, flexures—are approximately parallel. Sometimes also the lodes are divided lengthwise by parallel joints,t but the portions in which they abound are seldom rich. And when the rocks are of lamellar structure certain lodes which traverse them occasionally partake it also.J Whilst the lodes traverse calcareous strata their earthy ingredients are for the most part granular limestone and calcareous spar; but in the hornblendic series they are principally felspar, quartz, and hornblende. When however magnesia, alumina, and silica occur, as some- * Mr. William Phillips, Transactions of the Geological Society, n. p. 126. Mr. Carne, Cornwall Geological Transactions, 11 . pp. 50, 21. Dr. Boase, Ibid, iv. p. 448; Primary Geology, p. 176. Mr. Hopkins, Lond. and Edin. Philosophical Magazine and Annals (Third series), iv. p. 68 ; v. p. 130; ix. p. 369. Edinburgh New Philosophical Journal , xxn, (1836), pp. 156, 159. Cornwall Geological Transactions, v. p. 169. t M. Werner, Neio Theory of the formation of Veins (English Translation), pp. 87,107,136,214, 226, M. Daubuisson, Des Mines de Freiberg, I. p. 53. M. Jars, Voyages MHallurgiques, in. p. 93. M. De Luc, Geological Travels, in. pp. 266, 273. M. de Humboldt, Political Essays on New Spain , in. p. 229. M. Fournet, Etudes sur les depots Metalliferes, p. 43. Professor Sedgwick, Cambridge Philo¬ sophical Transactions , I. p. 108 ; Address to the Geological Society, 18th February, 1831, Proceedings of the Geological Society, i. p. 283 ; Philosophical Magazine and Annals, ix. (1831), p. 284 ; Geological Transactions, in. (n.s.) p. 483. Dr. Macculloch, System of Geology , i. p. 387. Mr. Westgarth Forster, Section of the strata from Cross Fell, to Nexocastle upon Tyne, p. 191. Mr. Fox, Report of the Royal Cornwall Poliyteclinic Society (1836), p. 93. Professor Phillips, Treatise on Geology (reprinted from the Enel. Britan.), p. 138. Mr. Burr, Mining Review, No. X. (1837), p. 66. Mr. (afterwards Sir H. T.) De la Beche, Report on the Geology of Cornxoall , Devon, axid West Somerset, p. 339. Cornwall Geological Transactioxis, v. pp. 179, 182, 232. M. Domeyko, Annales des Mines , 3me. Serie, xvm. p. 3. Mr. Whitney, Metallic Wealth of the United States (Philadelphia, 1854), pp. 52, 53. 7 Mr. Pryce, Mineralogia Cornubiensis, p. 95. Cornwall Geological Trans., y. pp. 181, 232. 86 W. J. Henwood, on the Mining times they do, amongst the calcareous rocks, the lodes afford pearl-spar, amianthus, felspar, and quartz, in addition to their ordinary constituents ; in like manner whenever lime forms either part of the rock or beds and veins in the hornblendic series, the lodes contain calcareous matter also. Thus to some extent all lodes partake in turn the nature of every rock they traverse.* * * § These changes are much more conspicuous in the cal¬ careous and hornblendic strata of Chanarcillo, than they are amongst granite and its congeners, in which similar ingredients^ are so differently aggregated. The contrast between such parts of the same lodes as traverse different rocks is much more manifest in their metallic than in their earthy constituents; for whilst contained in the hornblendic series they afford traces of blende and small quantities of iron pyrites only,^ but when bounded by calcareous strata they yield silver and most of its ores in almost unexampled abundance.^ The lodes are however by no means alike rich in every part of the three limestone formations ;|| but * Ante, p. 23, Note, + f Rev. J. J. Conybeare, Annals of Philosophy, vi. (n.s. 1823), p. 39. Dr. Boase, Cornwall Geological Transactions, iv. p. 391. De la Beche, Geological Manual (3rd. edition), pp. 440-443, 449-454. Researches in Theoretical Geology, pp. 295- 300. Dr. Boase, Primary Geology , pp. 131, 205. M. Delesse, Bulletin de la Soci6t6 GSologique de France, xv. (2me Serie), p. 782. Quarterly Journal of the Geological Society of London, xvi. (Translations and Notices), p. 11. J M. Domeyko, Annales des Mines, 4me. Serie, ix. pp. 437, 439. Colonel Lloyd, Report to the Foreign Office , on the Mines of Copiapo (1857), pp. 7, 8. § M. Domeyko, Annales des Mines, 4me. Serie, ix. pp. 437, 438. Colonel Lloyd, Report to the Foreign Office, on the Mines of Copiapo, pp. 7, 8. j| “La partie la plus riche du filon (elbenefcio ) suit de preference certains District of Chaharcillo in Chili . 87 contrariwise, when the rock is white, pale blue, or buff coloured, crystalline, and thin-bedded, they are little, if at all, more productive than they are in the horn- blendic series.* * This is strikingly exemplified at Colorado; where the principal lodc\ is unproductive throughout the second hornblendic formation; except in a thin interlying floor of limestone; in that, however, it yields both vitreous silver-ore, and native silver. But notwithstanding the bounding-planes of each formation by preserving the same level on either side of every lode afford proof that any motion, whether vertical or oblique, which may have taken place on one side of any lode , has extended in like manner to the other;—portions of the first limestone, which, at twenty-five fathoms deep form opposite sides (walls) of the Candelaria lode , differ widely in appearance.J Many white and pale grey beds alternate in the south-eastern or lower side (foot-wallJ, but a dark- grey, homogeneous thick-bedded limestone only occurs in the (hanging-wall) north-western.§ The former is straight and smooth, the latter crooked and rough. On both sides the two hornblendic dykes|| preserve their “ couches privilegiees, et que ce sont ces couches qui rendent le filon metallifere “ (son los mantos que hacen pintar la veta M. Domeyko, Annales des Mines, 4me. Serie, ix. p. 446. * “ The cleavage-planes of the schistose slates are almost invariably curved and “ contorted whenever the rock is quartzose, and in such cases it is usually very il fissile, and the laminae are highly inclined : either of these conditions is accounted “ inauspicious.”— Cornwall Geological Transactions , v. p. 225. t The Coloracla lode. Table III. J Ibid, pp. 195-204. § Table III. || Ante, pp. 80, 83. 88 W. J. Henwood, on the Mining ordinary parallelism in direction and dip. In them the lode is about three feet and a half wide; and, partaking their nature, consists for the most part of disintegrated felspar and hornblende. On entering the limestone, however, the irregularities of its north¬ western side (hanging-wall) distend it to twelve or fifteen feet in width on either side of both dykes (Table III., Fig. 8; # and then its chief ingredients are cal¬ careous spar, earthy yellowish brown iron-ore, vitreous and red silver-ore, and native silver. In such parts also the chloride and chloro-bromide of silver often encrust the joints. In great part of the calcareous series (a. c. e.f) dark grey and deep blue tints prevail, which, more pronounced amongst the deeper than in the shallower beds, pass occasionally into bluish black in the third limestone at Colorado and San Francisco naevo. These portions though sometimes granular, and often crystalline, are mostly massive in texture; and they afford every variety of lamellar structure. Isolated lumps and small irregular veins of calcareous-spar, are, at intervals, enclosed in the dark rocks. Hitherto the lodes have been rich whilst traversing the thick-bedded, homo¬ geneous, deeply-tinted limestones only; but even in portions of these, some parts of them are barren. Often, indeed, the other earthy ingredients are so much alike in both that it is difficult to distinguish the lode from the rock (country) at their contact; but * Ante, p. 83. t Ante, pp. 70-73. District of Chanarcillo in Chili. 89 as calcareous*spar sometimes forms continuous veins (leaders*) in the lodes and their branches; it is there¬ fore rather more abundant in them than in the dark- coloured limestone they traverse. Such parts contain many drusy cavities, which are encrusted with calcareous-spar, pearl-spar, and quartz ; but, though, spangled with rare crystals of silver and its ores, they are seldom rich.')' Many small hollows opening one into another, between blocks of limestone and ribs of calcareous-spar, form an irregular cavern,^ perhaps twenty fathoms long, twelve fathoms high, and from three to fifteen feet wide, in the Candelaria lode , about half-way down the first limestone, at Colorado .§ Large though isolated portions of the compact calcareo-ferruginous matrix are impregnated with native silver in masses, veins, and ramifications, of * Mr. William Phillips, Geological Transactions (o.s.), n. p. 138. Cornwall Geological Transactions , v. p. 208. + “ Rare and curious crystalline minerals * * * are seldom found in connection “ with large quantities of ore, although the lodes which afford them may be pro- “ ductive in other parts.”— Cornwall Geological Transactions, v. p. 206. J “ At Dolcoath a vugh 1 from eighteen to twenty fathoms in length, three “ fathoms high, and from four to nine feet wide ’ occurred in the Main lode. u Instead of a single large cavern, it, however, consisted of an infinity of small “ ones, opening into each other; or perhaps it may be more correctly described u as a part of the lode filled with vesicular carbonate of iron. At the Consolidated “ Mines , between the 110 and 120 fathoms levels, on Taylor's lode, a little west “ of Taylor’s shaft, a very extensive ‘ rough, ’ or cavity was discovered ; the size “ was much greater than is commonly observed, being nearly forty fathoms in “ length, and from one to two fathoms high; the direction was nearly horizontal, “ the lode both above and below producing good ore.” Cornwall Geological Transactions, v. p. 209, Note. See also Mr. Rule, Cornwall Geological Trans¬ actions , i. p. 225. Mr. Burr, Mining Review, No. VII. (July, 1835), p. 48. Mr. (afterwards Sir Henry Thomas) De la Beche, Report on the Geology of Cornwall, Devon , and Somerset, p. 324. § Table III. 90 W. J. Henwood, on the Mining every imaginable shape and size;—with the chloride of silver in like manner, bat in less abundance;—and with vitreous and red silver-ore in the same way, though in still smaller proportions.* Whilst the lodes traverse certain strata their joints and crevices are often encrusted and filled with the chloride of silver and native silver;— less frequently with vitreous and red silver-ore and the chloro-bromide of silver;—and, yet more rarely, with the bromide, and the iodide of silver. Occasionally also the same minerals interlaminate the rockf for short distances on either side of the lodes. Portions of all the lodes have been enormously rich. At about one hundred fathoms deep in the first lime¬ stone (a.) great part of the Candelaria lode , for a length of thirty-five fathoms, afforded so much native silver and chloride of silver, mixed with chloro-bromic, vitreous, and red silver-ore, that it averaged sixty, and some portions of it yielded nine hundred, (Troy) lbs. of silver per ton. The Colorada lode , whilst traversing the second limestone (c.) at one hundred and thirty five fathoms deep in Colorada and Desempeho , contains great quantities of comparatively inferior ore; so largely mixed, however, in some parts with native silver, the chloride, chloro-bromide, bromide, and iodide of silver. * M. Domeyko, Annales des Mines , 4me. Serie, ix. pp. 438-439. Colonel Lloyd, Report to the Foreign Office, on the Mines of Copiapo, p. 13. f “ On voyait de tout petits feuillets des chloro-bromures dissemines dans le “ roche encaissante.”—M. Domeyko, Annales des Mines, 4me. Serie, ix. p. 445. x Table III, District of Chanarcillo in Chili . 91 and with vitreous and red silver-ore, that sixteen hundred tons selected from it gave sixty four thousand lbs. of silver; # of which one-eighth part was obtained by two miners in a month. From this rich part of the Colorado lode several (branches) veins strike obliquely southward to Waring 9 s lode ; which, when alone, was barely an inch, but after their union with it was six inches wide. For five fathoms in length, and nine feet in height the lode maintained the same size, but it then entered a bed of white limestone and dwindled to its former dimensions. When small its only ingredient was calcareous spar; but during its enlargement this was mixed with the chloride of silver and vitreous silver-ore, and great part of it was so thickly intertwined with (bar-silver) native- silver ; that,—too tough for extraction with the ordinary mining tools, and too porous to be blasted with gun¬ powder,—it was cut out bit by bit with chisels.^ * Table III., PI. II. Q. f Table III. The besetting vice of Spanish America is so recklessly pursued in Chanarcillo, that on a pay-day groups of ill-clad native miners may be often seen playing at pitch and toss with silver dollars. When, also, the joint earnings of comrades, amounting to (a doubloon) an ounce of gold, are paid in a single coin, they some¬ times settle by a toss which of them shall pocket the whole. Many would there¬ fore starve were they not fed by their employers. Although all works at the surface and all entrances to the mines are within high-walled court-yards; the mouth of every shaft and (level) gallery is also closed by a gate, which is never opened unless in presence of an overseer, who may be summoned by a bell rung on occasion from within the mine. All ore brought to the surface is at once taken into small iron-fenced plots, within the walls; where, carefully guarded, it is (dressed) prepared for reduction. Native workmen never leave either the mine or the (dressing-floors) ore-plots until both their clothes and their persons have been strictly examined. I can, however, merely allude to the dangerous and disgusting manner in which they often unsuccessfully, attempt to secrete small lumps of rich ore. “ As the Mexican miners are almost naked and are searched on leaving the O 92 W. J. Henwood, on the Mining At a depth of thirty-eight fathoms in the first lime¬ stone (a.) the Colorado and Waring lodes* when nearly parallel and about five fathoms apart, meet and intersect the Counter lode , at horizontal angles of 68°— 70°, but do not (heave) displace it. The chloride of silver is obtained, in small though rich (bunches) masses, from Waring's lode; and, mixed with native silver, from the Colorado . Similar ores have been so abundant in the Gaunter lode that more than three thousand five hundred lbs. of silver were realized from the short range between its intersections. The Colorado and Waring lodes unite at a depth of one hundred and thirty fathoms in the second limestone (c.) ; and, for an extent of about fifty fathoms, yielded the chloride, chloro-bromide, bromide, and iodide of silver in small proportions, and vitreous and red silver- ore mixed with native silver so largely, that the pro¬ prietors of Desempeho and San Francisquito shared therefrom the proceeds of more than fifty-three thousand lbs. of silver.f Descubridora had been constantly and extensively wrought for five and twenty years, when, on preparing foundation for a storehouse, in the first limestone a few “ mine in the most indecent manner, they conceal small morsels of native silver, “ or red sulphuretted and muriated silver in their hair, under their armpits, in “ their mouths, and in other parts of their persons. * * * It is a most shocking “ sight to see * * * hundreds of workmen all compelled to allow themselves to “ be searched on leaving the pit or the gallery. A register is kept of the minerals “ found on them; * * * and in the mine of Valenciana at Guanaxuato the value “ of these stolen ores amounted in thirteen years to £36,000 sterling.” M. de Humboldt, Political Essay on New Spain, in. p. 247. * Ante, p. 81. Table III. t Tables III. IV. PL II. R. District of Chanarcillo in Chili . 93 feet only from the lode , a line of silver and silver-ore was unexpectedly laid open. This was the upper edge of a lenticular mass; which, about eighteen feet long, fifteen deep, and two and a half through towards the centre, was nowhere thicker than a crown-piece at its circum¬ ference. It afforded native silver, mixed and invested with the chloride, and chloro-bromide of silver in such rocks, that some of them like those obtained from the lode in 1831,-2,*—were temporarily used as card- tables.')' Within two months the formation was exhausted; meanwhile more than forty thousand lbs. of silver were extracted from it. But (hunches) masses of such richness, which occur at intervals only,J are generally surrounded by much larger bodies of inferior ore. Of this there remain, either still unbroken in the lodes or rejected at the surface, almost incalculable quantities, which might have been wrought to great advantage had Chanarcillo * Ante , p. 69. f Ante, p. 76. Note. t “ It appears that at the formation of veins * * * the distribution of silver “ has been very unequal; sometimes concentrated in one point, and at other “ times disseminated in the gangae , and allied with other metals. Sometimes in “ the midst of the poorest minerals we find a very considerable body of native “ silver, * * * which in place of being concealed in galenae, or in pyrites in a “ small degree argentiferous, or of being distributed through the whole mass of “ the vein over a great extent, is collected into a single mass. In that case the “ riches of a point may be considered as the principal cause of the poverty of the “ neighbouring minerals. * * * In Mexico, as well as in Hungary, large masses “ of native silver and vitreous silver-ore, appear only in a reniform shape; the “ composed rocks exhibit the same phenomena as the masses of veins. When “ we examine with care the structure of granites, syenites, and porphyries, we “ discover the effects of a particular attraction in the crystals of mica, amphibole, “ and felspar, of which a great number are accumulated in one point, while the u neighbouring parts are almost entirely destitute.” M. de Humboldt, Political Essay on Neio Spam (English Translation), hi. p. 160. 94 On the Mining District of Chaharcillo in Chili . / 9 been but sufficiently watered; under present circum¬ stances, however, the richest portions of it only are available. As no record is kept* either of ore from the mine, or of refuse whilst it is (dressed) made ready for reduction; the proportion of ore in the mass can be compared, neither with that in the (dressed) cleaned portion, nor with its produce. The proprietor of reduction works near Chaharcillo, derives a trifling profit when a ton (avoirdupois) of ore, from his own mine, will yield twenty-three (troy) ounces of silver; but he can buy none, of that produce, at a price remunerative to the miner. As some of the partners in Colorada are refiners of silver, they choose, as the Tinners in Cornwall anciently chosef, rather to divide the (dressed) cleaned ore, than to sell it amain and share its proceeds. The following extract from accounts kept at that minej may, perhaps, give a sufficient idea of the general produce. * “ At Valenciana ” in Mexico “ they know to within a few pounds the quality “ of gangue ” (vein-stuff) “ which daily goes out of the mine. * * * At the place “ of assemblage in the great pits * * * two persons (despachadores) are seated “ at a table with a book before them containing the names of all the miners “ (tenateros) employed in the carriage. Two balances are suspended before them ; “ and two assistants judge the weight of each carrier’s load. If the carrier “ believes his load to be a light one he says nothing; but, on the other hand if “ he thinks it heavier than usual he demands it shall be weighed, and the weight “ thus determined is placed to his account.” M. de Humboldt, Political Essay on New Spain, in. p. 248. f “ The sandie Tinne * * * after often cleansing, they call black Tynne, which “ is proportionably diuided to euerie of the adventurers.” Carew, Survey of Cornwall (Edit. 1769), p. 12. \ 3550 5 grains. = one Spanish Mark; 101*44 lbs. (avoirdupois). = one „ Quintal; 64* quintals. = one ,, Cajon. Kelly, Universal Cambist , i. p. 320, 322. Produce of the Colorado Mine. 95 1855. Quantity of ore. lbs. (avoird.) Oz. (troy) of silver per ton (avoir.) of ore. Quantity of silver oz. (troy). Monthly pro¬ duce of silver, oz. (troy), t January .... 18,960 230 1,948 57,212 255 6,512 8,920 1,622 637 460 February . .. 23,534 382 4,012 March. 3,448 255 392 | 16,388 . 40,170 892 15,996 1 April . 11,360 510 2,586 \ 29,214 255 3,326 j 5,912 May . 4,326 510 984 7 418 37,734 382 6,434 f June . 47 068 382 8,026 July . 10,548 460 2,166 August .... 25,968 255 2,956 y 22,722 306 3,104 11,048 21,910 510 4,988 J September .. 13,796 330 2,032 19,476 382 3,320 ( 3,842 255 436 ( 9,778 29,214 306 3,990 j October .... 34,084 204 3,104 1 404 306 56 8,286 22,518 510 5,126 November .. 11,360 306 1,550 ] 10,752 255 . 1,224 > 4,916 23,534 204 2,142 J December .. 4,462 1,020 2,032 1 34,894 485 7,554 9,586 lbs. 564,132 oz. 96,456 | Average proportion of silver in the ore T172 per cent., or 383 oz. (troy.) per ton (avoirdupois). 96 Produce of the Colorado Mine. 1856. Quantity of ore. lbs. (avoird.) Oz. (troy) of silver per ton (avoir.) of ore. Quantity of silver, oz. (troy). Monthly pro¬ duce of silver, oz. (troy). January .... 48,284 357 7,696 ) 6,492 3,825 11,086 V 30,042 34,084 740 11,260 ) February ... 30,836 255 3,510 \ 3,854 7,140 12,284 > 25,494 28,402 765 9,700 ) March .... 64,920 382 11,070 | 16,890 42,604 306 5,820 j April . 26,780 102 1,218 May ..... 21,504 127 1,218 ) 18,258 765 6,236 l 10,808 1,964 3,825 3,354 ) June . 15,418 306 2,106 -) 3,952 3,246 1,275 1,846 J July . 49,908 357 7,954 | 9,340 12,172 255 1,386 j August .... September .. 40,576 127 2,300 October .... 17,040 255 1,940 \ '*■ 21,910 306 2,992 V 6,390 7,100 460 1,458 j November .. 10,346 635 2,932 December .. 50,314 280 6,290 lbs. 556,012 - oz. 115,656 Average proportion of silver in the ore 1*426 per cent., or 466 oz. (troy) per ton (avoirdupois). On the Mining District of Chaharcillo in Chili, 97 Although these columns show the quantities of ore shared by the proprietors of Colorado, in 1855—6, the produce they record is merely that of the native silver, the chloride, chloro-bromide, and other amalgamable compounds of silver (metales calidos) it contains. To this we must add the proceeds of smelting the vitreous, red, and other rarer ores (metales frios); which— occurring in every metalliferous part of the lodes, but more abundantly in some calcareous strata than in others,—yield from ninety to one hundred and twenty (troy) ounces of silver per (avoirdupois) ton of ore; or from 0*275 to 0*367 per cent. Taking the weight of (dressed) cleaned ore at unity, the proportion of silver extracted from it— by amalgamation.in 1855 was 0*01172* „ . 1856 „ 0*01426* u . C „ 0*00279* smelt,n S. i ” 0-00367* or on an average. 0*012964 to 0*012966'j' a produce much smaller than that of earlier years. * “ In most Countries the precious metals and their ores are weighed by different “ Standards ; but to facilitate comparison, it has been thought best to express “ decimally the proportion of the one in an unit of the other everywhere.” t “ The quantity of silver extracted from the minerals by means of mercury, “ is in the proportion of 3| to 1 of that produced by smelting. This proportion “ is taken from the general table formed by the provincial treasuries, from the “ different districts of mines in New Spain. There are however, some of those “ districts, for example those of Sombrerette and Zimapan in which the produce “ from smelting exceeds that of amalgamation.” M. de Humboldt, Political Essay on the Kingdom of New Spain , hi. p. 250. 98 W. J. Henwood, on the Mining Nearly one half the produce is native silver ;—about one-third is obtained from the chloride of silver,—and (a.) “ The most abundant silver-ore in Chili is the chloride, which is associated “ with the bromide of silver and native metal. Besides these, there are a great “ variety of sulphurets and arseniurets. Their yield is from 0*003 to 0*008 ; the “ richest contain 0-02 of silver.” Whitney, Metallic Wealth of the United States, p.173. “ The produce of the mines of Chili, has considerably increased of late years. “ At eight leagues distance to the north-west of Mendoza the Cerro de Uspallata “ contains masses so rich that they yield from 0T3616 to 0*2 of silver.” M. de Humboldt, Political Essay on New Spain, in. p. 353. (5.) “ The contents of the minerals of Potosi ” in Peru “ have diminished in “ proportion to the increase in the depth of the works. “ In 1545 a produce of from 0*4 to 0*45 was very common ; “ „ 1574 the mean contents were from 0 04 to 0*045, and minerals which “ yielded 0*25 were considered extremely rich ; “ ,, 1607 the mean contents were from 0*00625 to 0*000937. “ Since the commencement of the eighteenth century,— 0*000303 to 0 000404. “ The minerals of Potosi are consequently extremely poor, and it is on account “ of their abundance alone, that the works are in such a flourishing state. It is “ surprising to see that from 1574 to 1789, the mean riches of the minerals have “ diminished in the proportion of 170 to 1, whilst the quantity of silver extracted “ from the mines has only diminished in the proportion of 4 to 1.”— Ibid, p. 373. “ The mean wealth of the minerals * * * in the mines of Pasco in Peru is “ 0*000717.”— Ibid, p. 166. Note. “ The mines of Cerro de Pasco * * * have grown sensibly poorer in descending. “ * * * The tenor of the ores, which at the surface sometimes amounted to 0 3, “ and averaged 0*0015, now hardly surpasses 0 0004.”— Whitney, Metallic “ Wealth of the United States (Philadelphia, 1854), p.169. (c.) “ In New Granada the depository of argentiferous minerals of Santa Anna “ near Mariquita forms a bed in the gneiss and yields on an average 0*00407 of “ silver.” M. de Humboldt, Political Essay on New Spain , in. p. 387. ( d .) “ In Mexico, the mine of Yalenciana, “ in the total mass of minerals pro¬ duced during the year 1791, afforded— “ *0001 of rich minerals ( polvillos and Xabones) which yielded *111905 of silver ; “•0028 ,, ( apolvillado ) ,, *046886 ,, ; “ *0152 „ ( bianco bueno ) ,, *015630 „ ; “ *0215 of poor minerals (granzas, tierras ordinarias, &c.) „ *001873 „ ; “ and produced on an average. *005814 ,, ; “ In the district of Pachuca the produce of the Biscaina vein is divided into “ three classes ; of which the richest yielded from ” 0*003000 to 0*003302 of silver; ,, second „ „ 0*001250 ,,0*001687 „ ; ,, poorest ,, about 0*000662 „ District of Chaharcillo in Chili. 99 the remainder from vitreous and red ore, the chloro- “ In the district of Tasco the minerals of Tehuilotepec yield about 0*001250 of silver ; those of Guautla . 0*002250 ,, . “ Investigations made by Don Fausto d’Elhuyar, Director General of the Mines il of Mexico, and by several members of the Superior Council of Mines show the “ mean riches of the silver minerals is from.... 0*0018 to 0*0025; “and Don Jose Garces y Eguia, who directed extensive mining operations in “ several districts, says (Nueva Theoretica delbenefcio de los metales (Mexico, “ 1802), pp. 121, 125), that 1 the mean riches of Mexican minerals amounts only “to . 0*001375.’ M. de Humboldt, Political Essay on New Spain, in. pp. 162, 163, 165, 166. (e.) “ The silver furnished by the United States comes almost wholly from the “ native gold of California. There is no proper silver mine within our territory, “ although there are several localities where a small amount of this metal is “ obtained in connection with lead ores. In the State of New York the lead-ore of the Coal Hill mine affords traces of silver >> >> y> >> >y >) New Hampshire ,, Eaton „ „ ,, Shelburne ,, Connecticut „ Lane’s ,, ,, the lead of .... Middletown ,, Pennsylvania the lead-ore (galena) of Chester „ ,, ,, (phosphate of lead) „ „ North Carolina the lead of Washington mine, in 99 99 0*001000 99 99 0*001500 )) 99 0*002000 ) to 0*003500 ] 99 99 0*000637 ) to 0*001911 ] 99 99 0*000372 l to 0*000506 S 99 99 0*000020 99 1844, afforded 0*007500 1851, „ 0*008719 of auriferous silver, which contained on an average 23*2 per cent, of gold. Mr. Whitney describes the Upper Mississippi and Missouri lead districts very minutely; but he makes no mention of their having afforded silver. Large quantities of native silver encrust the rich deposits of native copper, which are extensively wrought in many places, near the (Michigan) southern shore of Lake Superior; but great part of it is secreted by the workmen. “ The silver rarely form lumps of more than a few ounces in weight, although “ some pieces weighing several pounds, and nearly pure, have been obtained. * * * “ The amount of silver obtained from the Cliff Mine has sometimes been quite “ considerable * * * it is mostly picked by hand from the coarse metal taken out “ from under the stamp-heads.” During the four years 1848-51 the proportion of silver was 0*0000135 the weight of ore stamped. Whitney, Metallic Wealth of the United States, pp. 180; 266-305; 381-421. Australia supplies Europe with large quantities of the sulphate of lead, which yields, on an average, 0*350000 its weight of lead, and 0*001071 „ silver, beside a little gold. Mr. J. Arthur Phillips, Journal of the Society of Arts, 27th April, 1859. D 100 W. J. Henwood, on the Mining bromide, bromide, iodide, and other yet rarer com¬ binations of the same metal. (_/.) “ The silver-ore of Kongsberg in Norway was divided into four parts; “ whereof the first . contained about . 0-66 its weight of silver; „ second. „ from 0*11361 to 0*118154 ,, „ ; „ third (picked) ,, about. 0 006816 „ ,, The fourth (stamped and washed) is subdivided into three parcels ; of which the best .... contained about . 0*004544 „ ,, ; „ average.. „ from 0*00142 to 0*001704 „ ,, ; ,, poorest.. „ ,, 0*000284 „ 0-000568 ,, „ M. Jars, Voyages Mitallurgiques , ii. p. 103. The proportion of ore in each parcel is not mentioned. “ Those portions of rock which adjoin the veins and partake of their nature “ (faldband) contain, occasionally, small quantities of native silver and the “ sulphuret of silver; but seldom exceeding a 0 - 00007l part of the mass, they “ will not repay the cost of the extraction.” M. Daubree, Annales cles Mines , 4me Serie, iv. p. 258. M. Durociier, Annales des Mines , 4me Serie, xv. p. 378. 11 At Sala the proportion of silver obtained is 0*014800 the weight of cleaned ( dressed ) galena, or 0-017200 „ „ lead.” M. Durocher, Annales des Mines , 4me Serie, xv. p. 345. “ In the Banat auriferous pyrites from Tsiklova afforded 0 004677 its weight of silver.” M. de Chancourtois, Annales des Mines , 4me Serie, x, p. 583. ( g .) “ Near Chemnitz in Hungary one part of the Spitalergang yields 0*000040 its weight of silver, and 0*000005 ,, gold; whilst another affords 0-000045 its weight of silver, 0 0000058 ,, gold, and 0*031970 ,, lead. In the same district the Thire.se vein gives 0-000025 its weight of silver, 0*000005 ,, gold, and 0 004600 ,, lead. The Biebergang furnishes 0-000059 its weight of silver, and 0*0000001 „ gold. The Gru?iergang, in the same neighbourhood, presents 0*000078 its weight of silver; the mean produce of the district being 0*0000484 the quantity of crude ore extracted.” MM. Rivot & Duchanoy, Annales des Mines , 5me Serie, in. pp. 358-363. M. Pache, Annales des Mines, 4me Serie, x. p. 595. District of Chanarcillo in Chili. 101 But all these ores are not alike plentiful, whilst the “ The silver ores of Nagybania afford 0*000536 their weight of silver, and 0 000015 ,, gold; those of Neusohl 0*000915 their weight of silver, 0-000018 „ gold. The lead ore of the same districts yields 0*000117 .. their weight of silver, 0*0000016.. ,, gold, and 0*057 to 0*085 ,, lead.” MM. Rivot & Duchanoy, Annales des Mines, 5me Serie, hi., pp. 365-6. / “At Przibram, in Bohemia, the cleaned (dressed) ore yields on an average 0*375000 its weight of lead, and 0*002228 „ silver.” M.de Hennezel, Annales des Mines, 4me Serie, i. p. 40. (A.) “ At Clausthal, in the Hartz, picked and sifted ore mixed with that which “ had been stamped and washed, in proportion of about seven to three, affords 0*001016 its weight of silver, and 0*553 „ lead.” M. de Hennezel, Annales des Mines , 4me Serie, iv. p. 339. M. de Bonnard, Annales des Mines, vn. p. 59. (i.) “ Throughout the district of Freiberg, in Saxony, the proportion of silver “ obtained from cleaned (dressed) silver ore was, in 1762 .. _ 0*000994 its weight. — 1781 ... ... 0*001136 its weight. 3 .. 99 2 ... ... 0*001230 99 4 .. 99 3 ... 99 5 .. _ 0*001065 99 4 ... ... 0*001349 99 6 ^ _ 0*000994 5 ... ... 0*001136 7 .. 99 99 6 ... 99 8 , 99 7 ... 99 9 . . 0*001207 99 8 ... ... 0*001207 99 1770 . 99 9 ... u 1 .. .... 0*001136 y 1790 ... 99 2 .. 99 1 ... >> 3 .. 99 2 ... ... 0*001349 >) 4 .. _ 0*000994 )} 3 ... 99 5 .. 99 4 ... ... 0*001349 99 6 .. 99 5 ... ... 0*001278 99 7 .. .... 0*001136 9 9 6 ... ... 0*001349 )> 8 .. 99 7 ... j> 9 . 99 8 ... 99 1780 .. » 9 ... 99 1800 ... 99 During these thirty-nine years, therefore, the average produce of silver “ 0*001211 the weight of the (dressed) ore from which it was extracted. 102 W. J. Henwood, on the Mining lodes traverse, even congenial portions of, the different limestone formations. u In all other parts of the Erzgebirge the silver ores are so much richer; that in 1763.they averaged 0-010508, ,, 1799. „ 0-004544, and during the interval ,, 0-008520.” M. Daubuisson, Des Mines de Freiberg en Saxe (1802), n.pp. 122-4. M. de Humboldt, Political Essay on New Spain (1811), hi. p. 167. (j.) te Mines of lead-ore, rich in silver, were anciently wrought in Sicily and “ Calabria, but they are now neglected.” M. Paillette, Annales des Mines, 4me Serie, ii. p. 613. (A.) “ From the Sierra Almagrera, in Spain, cleaned ( dressed) fine-grained .... galena from the Carmen mine yielded 0-717996 of lead &, 0-010495 of silver; radiated . tt tt tt 0-630993 tt 0-006498 „ ; black argillaceous ft tt tt 0-220693 tt 0-003227 „ ; it ft from Aguilas ft 0-637470 tt 0-003497 „ ; large grained .. tt ,, Pietad tt 0-600000 it 0-000997 „ ; carbonate of lead . tt tt tt 0-415996 a 0-001245 „ . “ Assays of ore from other mines in the same district produced from 0-600000 to 0-78850, and averaged. 0*719770 of lead; and “ 0-000140 ,, 0-000900, „ . 0000260 of silver: massive carbonate of lead from Cape de Gat gave.... 0-002820 ,, .” M. Paillette, Annales des Mines, 4me Serie, n.pp. 306, 318. M. Berthier’s analysis afforded from 0-380000 to 0-790000, and averaged 0-618333 of lead; „ 0-001000 „ 0-010800, „ 0-005910 „ silver; showed that the silver mixed with lead-ore in this district is a sulphuret, and proved that it contained no gold.— Annales des Mines , 4me Serie, in. p. 823. M. Sauvage’s assays indicate the proportion of silver to have been 0*004 the weight of crude ore from the mines of Almagrera. Annales des Mines, 4me Serie, iv. p. 107. “ During the first six months of 1843, first class ore formed about 40, and “ second quality perhaps 60 per cent, of the mass ; and the proportion of lead it afforded was from .. 0-200000 to 0-220000; and „ silver ,, nearly 0-002200: but in the corresponding part of 1844 first class ore was only 12 or 15 per cent., and the proportion of lead declined to. 0-100000 or 0-110000; and „ silver „ 0-001150 „ 0-001250. Galena obtained from slate is richer in silver than that from limestone in this district.” M. Pernollet, Annales des Mines, 4me Serie, ix. pp. 65, 77; x. p. 256. Mr. Michell, Director of very extensive Reduction Works in this district, during its richest period, found the average proportion of lead .... 0-180000 the weight of ore; and of silyer .. 0-002204 „ „ ; or 0-012245 „ lead. Cornwall Geol. Trans., vi. p, 314. District of Chanarcillo in Chili. 103 la the third limestone the lodes , beside their earthy At Arrayanes, near Linares, in the province of Jaen, the proportion of silver was between 0*000184 and 0*000214 the weight of cleaned (dressed) ore; or 0*000306 ,, lead. At Pozo Ancho, in the same neighbourhood, the proportion was about 0*000248 the quantity of cleaned ore ; or 0*000367 „ lead; and this is nearly an average throughout the district. Although this lead is smelted in Spain, the silver it contains is, for the most part, extracted either in England or in France ; a small quantity only being separated at La Carolina, near Linares.— From the MSS. of Henry Thomas, Esq., F.G.S., Director of Works at Pozo Ancho. The galena of Linares yields from 0*700000 to 0*720000 its weight of lead, and ,, 0 000280 ,, 0,000490 ,, silver. M. Lan, Annales des Mines, 5me Serie, xn. pp. 626, 628. The mines of this district are mentioned by M. le Play, Annales des Mines , 3me Serie, v. p. 184; M. Paillette, Annales des Mines , 4me Serie, n. pp. 313, 317; Mr. Whitney, Metallic Wealth of the United States, p. 379; Professor Ansted, Scenery , Science, and Art, p. 141, Note. “Argentiferous galena occurs in the Barranco de Val de Plata between Moncayo and Saragossa.”—M. Leitao, Annales des Mines, 5me Serie, i. p. 109. (i.) The mine of Chalanches, near Bourg d’Oisans in Dauphiny, afforded silver in the proportion of from 0*090888 to 0*181777 the quantity of the nickel, cobalt, and iron-ores with which, beside other ingredients, it was mixed.—M. de Bournon, Journal de Physique (1784), xxiy. p. 202. M. Schreiber, Journal de Physique, xxiv. pp. 380, 387. M. Hericart de Thury, Journal des Mines (1806), xx. p. 46. M. Lefebvre, Noticesur les Minerals et Usines des Chalanches d’Allemont et du Grand Clos (Paris, 1852), pp. 4-10. M. Lory, Bulletin de la SociM Gtologique de France, 2me Serie, vn. p. 541; xv. p. 13. Cleaned (dressed) lead-ore from Montjean, near Vizille, in the same Province, produced 0*430000 its weight of lead, and 0*001154 „ silver. M. Hericart de Thury, Journal des Mines, xxi. p. 267. The argentiferous galena of Pesey, near Mohtiers, in the Department of Mont Blanc, yielded in— 1803 • • lead • • • • 0*370000 .. silver .. 0*001000 1805 • • lead • • • • 0*540000 ji .. silver .. 0*001320 the weight of cleaned (dressed) ore. Differently constructed furnaces were used in each of these years; during which equally discrepant results were obtained from ore of uniform quality.— M. Leliyec, Journal des Mines, xx. pp. 442, 448. M. Schreiber, Journal des Mines, xxi, p. 58. M. Berthier, Annales des Mines , 3me Serie, hi. p. 549. __ E 104 W. J. Hen wood, on the Mining ingredients, contain vitreous and red silver-ore, blende, The proportion of silver obtained from cleaned (dressed) lead-ore at Pontgibaud, in the Department of Puy de Dome, was— in 1846 . 0 001188 of its weight. „ 1847 . 0-001068 „ „ 1848 . 0-001038 „ 1849 . 0 001023 „ MM. Rivot & Zeppenfeld, Annales des Mines, 4me Serie, xvm. pp. 254, 443, M. Guenyveau, Annales des Mines, vn. pp. 189,192. M. Berthier, Annales des Mines , 3me Serie, n. p. 112. M. Fotjrnet, Annales des Mines, 3me Serie, ii. p. 139. Mr. Whitney, Metallic Wealth of the United States, p. 380. The produce of lead ore from Carnoules, near Alais, in the Department of Gard, was . 0-343356 its weight of lead ; 0*000718 ,, silver. M. Lan, Annales des Mines, 5me Serie, ix. p. 349. M. Boulanger, Annales des Mines , 3me Serie, vn. p. 579. Professor Ansted, Scenery, Science, and Art, p. 20. In 1823, the galena of la Lozere afforded on an average 0-001039 its weight of silver.—M. Marrot, Annales des Mines , xvm. p. 489. M. Lan, Annales des Mines, 5me Serie, Vi. p. 401; vii. p. 1. Several mines in the Department of Aveyron yield argentiferous galena.— M. Blavier, Journal des Mines, xx. pp. 201, 209, 210, 223, 276, 285, 287. M. Boyse, Annales des Mines, 5me Serie, n. pp. 496, 500, 512. “ I lately obtained from * * * a mixed copper and lead ore from Pichiguet, 0*250000 its weight of lead, 0-180000 „ copper, 0-000827 „ silver, and 0-000144 „ gold.” Professor Ansted, Scenery, Science, and Art, p. 21. At Poullaouen , in Finisterre, the cleaned (dressed) ore yielded,— before 1807 . 0-600000 its weight of lead, and 0-000470 ,, silver: in. 1846, from 0 000200 to 0 000500 „ silver. At Huelgoat, in the same Department, the proceeds were,— in 1807, from galena, 0-550000 its weight of lead, and 0-002400 ,, silver: in 1846, ,, between 0-001000 & 0*002000 its weight of silver; and from blende, ,, 0*000200 ,, 0*000400 „ „ . In 1774, Huelgoat afforded an earthy black ore, from which M, Duhamel extracted. 0 009380 its weight of silver. In 1807 no silver seems to have been obtained at Huelgoat but that separated from the galena. Previously to 1846, however, large quantities of native silver, of the chloride District of Chanarcillo in Chili . 105 and iron pyrites, sometimes mixed with small quan- and chloro-bromide of silver, and of plumbiferous sulphuret of silver, had been wrought from the surface to about ninety-five fathoms in depth. The plumbiferous sulphuret of silver yielded at times as much as O’120000 the other ores. sometimes contained ,, 0.003500 but the general produce was . from 0-000500 to 0 002000 the weight of ore. M. Daubuisson, Journal des Mines , xx. p. 352; xxi. pp. 83, 88. M. Pernollet, Annales des Mines , 4me Serie, x. pp. 383-453. Mr. Whitney, Metallic Wealth of the United States, p. 380. “ A brown indurated oxide of iron which formed the upper part of a metal- “ liferous bed in the higher grounds of Cronebane,” in Wicklow, “ was found to “ contain minutely disseminated native silver, sometimes in extremely slight “ filaments, but generally in particles quite imperceptible to the eye * * * * “ It contained about thirty grains of gold in the ounce, equivalent to per “ cent., and hence the auriferous silver commonly sold for half a guinea an “ ounce.”— Mr. Weaver, Geological Transactions , v. p. 213. In different parts of the United Kingdom lead-ores afford silver in various proportions: viz.— Ireland, Waterford .. Wicklow .... Isle of Man. Scotland. Argyle. Dumfries ... Perth ... ^, Kircudbright. East Shallee . Gurtnadyne . Garryard . Luganure § Glendalough 7. i Foxdale .... Laxey . North Laxey South Manx Strontian ... Caimsmore . Wanloch Head (as corrected in 1857*).. Tyndrum ... East Black Craig ........ Kirkudbright .. 1856. Proportion of Silver in Lead-ore. Lead. 0*000044 0-000062 1857. Proportion of Silver in 0-000414 0-001028 0-000316 0-000042 0-000022 0-000149* 0-000060 0-000009 0-000070 0-000106 0-000568 0-001439 0-000457 0-000060 0-000030 0 000205* 0-000084 0-000012 Lead-ore. 0-000043 0*000044 0-000055 0-000414 0-001028 0-000338 0-000044 0-000137 0-000044 0-000010 Lead. 0-000070 0-000070 0-000106 0-000566 0-001439 0-000459 0-000060 0-000191 0-000067 0-000014 Mr. Hunt, Memoirs of the Geological Survey of Great Britain. —Mineral Statistics 1856, pp. 39, 40; 1857, pp. 42, 43. “ -A-U the lead raised in England and Wales contains silver in variable pro- “ portions. * * * Half of that from Flintshire and Denbighshire contains from “ 4| to 6| oz. (0-000137 to 0*000198), and the other half 9 or 10 oz. (0-000275 “ to 0*000306) of silver per ton.” Mr. Pattison, Reports of the British Association } yu. (1836, Notices.) p. 50. 106 W. J. Henwood, on the Mining tities of native silver also; but they afford scarcely a Wales. Flint.. Denbigh .... Merioneth .. Montgomery . Cardigan .... Belgrave . ' Boddelwyddan Brynford Hall Brynsteddfod .. Caylan . Comebine .... Beep Level .... Garreg . Grosvenor Level Holywell Level Herward .... Maes-y-safn .. Michell . Merllyn . Mold . Nant . 1856. Proportion of Silver ii Lead-ore. Lead. 0-000024 0-000156 0-000124 0-000005 0*000040 0-003503 0-000088 0-000140 0 000208 0-000198 0-000141 0-000056 0-000043 0-000136 0-000111 0-000033 0-000214 0-000169 0 000007 0 000057 0 005193 0-000122 0 000183 0 000323 0 000275 0-000196 0 000076 0-000061 0 000189 0-000153 Nniif.-v-mawr .. 0-000130 Hant.-n-aoa .. Orsp.tl.rl. .................. 0 000141 0-000109 0-000124 ]Prf.n.f.-y-m.inyni ... Ppnrhiiii.-ddu ............ Pen-yi'-h.enhlas .. Pirll.inli.pnl .............. SSpp.pdivp.il .. 0-000041 0-000201 0-000134 0-000226 0-000104 0-000043 0-000049 'Tala,ere ... . , t Maes-yr-erwddu Talargoch { Coeti / Llys .... 'Tnrharh, ................ Piim.ap.n. ................ Wpsf/m.in st.er .. Pins Hewvdd .. Mnps-n-sa fn ............ 0-000136 0-000022 A hprdnmi .. Prince of Wales ........ Ttryn-y- Pedwen .......... 0-000280 Canla.n. ................ Dvliife .. •• •• 0-000097 0 000095 0-000130 0 000058 0-000179 0-000086 Onfn.mrni. .............. T.lanerrhijinawr . Hnnf.-n-ni.nirr .. Hant.il ... Phimn.rth. .. A hertFriiwdd ... A hhp.ii Onn.snls .. .......... Prnnavinn .. 0 000060 Tirniidniid. .. Bnileh. Consols .. 0-000437 0-000065 0-000298 Cejn. Tirwyno ... Ciiim, Erdn .. Cnnn. Siphon. ... Darren .. 0-000504 0-000186 0-000196 0-000158 0-000171 0-000057 0-000292 0 000184 0-000306 0-000151 0-000078 0 000067 0-000184 0 000031 0-000376 0-000112 0-000129 0-000178 0 000080 0-000266 0-000140 0-000084 0 000570 0-000090 0-000495 0-000812 1857. Proportion of Silver in Lead-ore. Lead. 0-000170 0-000245 0-000134 0-000184 0-000088 0-000122 0 000131 0-000183 0-000258 0 000345 0-000109 0-000153 0-000136 0-000191 0-000103 0-000146 0-000090 0 000119 0-000086 0-000115 0-000113 0-000160 0-000045 0-000062 0-000041 0-000058 0-000200 0-000275 0-000200 0-000275 0-000050 0 000069 0-000179 0-000245 0-000062 0 000085 0-000138 0 000195 0 000101 0-000152 misprinted in original. 0-000091 0-000127 0-000040 0-000061 0 000101 0-000137 0-000127 0 000171 0 000256 0-000307 0-000393 0-000570 0-000069 0-000097 0-000388 0-000566 0-000775 0-001010 0-000590 0-000918 District of Chanarcillo in Chili . 107 trace of either the chloride or chloro-bromide of silver. Whilst the lodes traverse the second limestone their Cardigan (con¬ tinued) .... Caermarthen . Dohoen .. Eagle-brook .., East Darren .., Esgair Mwyn , Goginan ...., Lisburne Mines Llett-y-hen ... Llwynmalees New Lisburne . Paxitmawr ... Penycefxi . Taliesin . Thomas United Ty Llwyd . Welsh Potosi . Nant-y-Mxoyn . Vale of Towey . 1856. Proportion of Silver in Lead-ore. Lead. 0-0001740-000247 000459 000033 000612 000052 0-000489 0-000336 0-0003210- 0-0000230 0-0004450 0-0000360 0-000319 0-000284 0*000128 0 000774 0-000195 0-000265'0 0-0000980 0-000175 0 -000177 001084 000306 000377 000134 000245 1857. Proportion of Silver in Lead-ore. 0-001202 0-000130 0-000348 0-000083 0-000479 0-000016 0-000334 0-000214 0-000140 Lead. 0-001695 0-000193 0-000505 0-000117 0-000704 0-000022 0-000490 0 000338 0-000200 0-000131 0-000070 0-000042 0 000182 0-000103 0-000064 Mr. Hunt, Memoirs of the Geological Survey of Great Britain ,— Mineral Statistics. 1856, pp. 35-39 ; 1857, pp. 38-42. “ Lorsque les 21 quintaux contenoient un marc d’argent ou seulement 6 “ onces,” (0-000245 or 0-000183) “ on pouvoit affiner le plomb avec avantage.” M. Jars, Voyages Mdtallurgiques (1766), ii. p. 554. “ Silver is contained in the ore in different proportions, varying from 2 to 42 “ ounces in the fother of 21 cwts. ” (0-000061 to 0-001285) ; “ but 12 ounces ” (0*000367) “ may be considered as the general average. If 7f or 8 ounces ” (0 000230 or 0 000245) “ can be extracted the lead is worth refining.” Mr. Winch, Geological Transactions, iv. p. 82. See also Mr. Westgarth Forster, Section of the Strata from Newcastle-upon- Tyne to Cross Fell, p. 399. “ In Durham and Northumberland * * * many lead ores contain a much u larger portion of silver than the average of * * * the ores of Mexico and “ Peru.”— Rees, Cyclopcedia, xxxn.— Silver. “ Of 22,000 tons of lead yielded in the district of Alston Moor, it is believed il that 16,000 tons contain silver at the rate of from 6 to 12 oz. per ton ” (0*000183 to 0*000367), “and 6,000, from 3^ to 6 oz. per ton ” (0-000107 to 0-000183),—“the average being about 5 oz. ” (0-000153). “ 4,700 tons from “ Swaledale, Wharfdale, Pateley Bridge, &c., yield on an average only 2 oz. per “ ton ” (0-000061). Mr. Pattinson, Reports of the British Association, vn. (1836) Notices, p. 50. 108 W. J. Henwood, on the Mining productive portions afford vitreous and red silver-ore, England. Durham and Northumber¬ land . Cumberland.. 1856. Bollyhope . Allergill . Fallowjield . Hallywell . Derwent Mines . Lunehead . East and West Allandale and Weardale . Brandon Walls . Calves .. Stonecroft . Settling Stones . Captain Cleugh . Healey Field . Stow Craig . Clargill Head . Crossgill Head . Grassfield . Roughtengill . Black Syke . Driggitt ... Gaily gill Syke . Hudgill Burn . Holyfield . Nattras North Vein .. Low Birchy Bank .... Nattras Middle Vein .. Brigal Burn . Bentyjield. East End , Sun Vein . Dowpot Syke . Windy Brow . Goldscope . South Crossfell . Middle Tyne Green .. Force Craig . Green Banks . Carrs West of Nent .. Calvert . Dosey . East Crossfell . Allen's Clough . Park Grove Sun Vein .. Thorngill , West End .. Lady Vein . Douke Burn , West End . Peat Stack Hill . Thorngill , East End .. Tees Side § Metal Band . Patter Syke . Rodderup Fell . Proportion Lead-ore. 0 000301 0-000146 0 000208 0-000154 0 000182 0-000157 0-000140 0-000123 0-000097 0-000133 of Silver in Lead. 0-000428 0-000204 0-000291 0-000263 0*000275 0 000214 0-000184 0-000184 0-000177 0-000184 0-000347 0-000921 0-000942 0-000550 0-000287 0-000584 0-000388 0-000398 0-000358 0-000365 0-000321 0-000326 0-000283 0 000381 0-000292 0-000490 0-001377 0-001360 0-000926 0-000800 0 000900 0-000612 0-000612 0-000548 0-000579 0 000490 0-000459 0-000444 0-000437 0-000433 0-0002830-000428 0-000262 0-000254 0-000105 0-000152 0-000410 0-000376 0-000153 0-000214 0-000142 0-000161 0*000167 0-000174 0-000240 0-000245 0 000245 0-000245 0-000131 0-000156 0-000155 0-000146 0 000145 0-000144 0-000122 0-000151 0-000216 0-000214 0-000234 0-000213 0-000214 0-000214 0-000214 0-000214 1857. Proportion of Silver in Lead-ore. Lead. 0-000267 0-000434 0-000196 0-000291 0-000208 0-000291 0-000162 0-000245 0-000150 0 000214 0-000143 0 000214 0 000146 0-000183 0-000131 0-000184 0-0001310 000184 0-000133 0-000184 0*000066 0-000092 0-000100 0-000139 0-000291 — 0-000920 0-001377 0-000928 0-001360 0*000630 0-000900 0-000581 0-000900 0-000437 0-000612 0-000398 0-000612 0-000388 0-000543 0 000369 0-000518 0-000348 0 000489 0-000309 0-000451 0-000305 0-000427 0 000306 0-000428 0-000257 0-000372 0 000139 0-000300 0 000175 0-000262 0-000176 0-000246 0-000167 0 000245 0 000175 0-000245 0-000160 0-000242 0-000162 0-000242 0 000180 0-000242 0-000150 0-000230 0-000158 0-000222 0-000157 0 000220 0-000158 0-000217 0-000151 0-000214 0 000150 0-000213 0-000144 0-000211 0-000113 0-000209 0-000143 0-000204 District of Chanarcillo in Chili . 109 in like proportions to those beneath; native silver is, Cumberland (continued) . Westmoreland Yorkshire.... Longcleugh, Ramp gill, $c. Blagill . Wellgill Cross-vein .... Brownley Hill . Douke Burn, East End .. Lee House Well . Greens ide . North Stainmore . Brandlehow and Barrow . 1856. Proportion of Silver in Lead-ore 0 000189 0-000119 0-000121 0-000091 0-000082 0-000905 0-000357 0-000222 Lead. 0*000275 0-000184 0-000182 0-000122 0-000117 0-001525 0-000506 0-000306 Keswick . Nether Hearth Brathwaite ... 0-000082 0-000122 0-000061 0-000087 0-000118 0-000168 1857. Proportion of Silver in Lead-ore. 0-000131 0-000130 Lead. 0-000184 0-000184 0-000087 0-000122 0-001078 0-000357 0-000222 0-000182 0 000490 0-000306 0-000260 0 000060 0 000092 0-000141 0-000209 Mr. Hunt, Memoirs of the Geological Survey of Great Britain — Mineral Statistics. 1856, pp. 31-34; 1857,pp. 33-37. “ The lead of Derbyshire and Shropshire yields on an average from 1 oz. to “ ljr oz. only of silver per ton ” (0-000030 to 0*000046 its weight). Mr. Pattinson, Reports of the British Association , vn. (1838) Notices, p. 51. Mr. Hunt particularizes the lead-ore and lead obtained from Derbyshire, Shrop¬ shire, and Somersetshire, but makes no mention of silver extracted from any of it.— Memoirs of the Geological Survey of Great Britain . —Mineral Statistics, 1856, pp. 30, 31; 1857, pp. 32, 33. “ Betwixt the twelfth daie of August and the last of October in ” (1294) “ the “ 22 yeare of this king” (the first) “ Edward’s reigne there was tried and fined “ out at Martinstowe in Deuonshire by times so much fined siluer, as amounted “ to the summe of 370 pounds weight. In the 23 yeare of his reigne there was ‘‘fined at the place aforesaid 521 pounds and ten shillings weight of silver by “ times. In the 24 yeare of his reigne, there were taken vp 337 miners, within “ the warpentake of the Peake in Darbishire, and brought to Deuonshire, to work “ there in those siluer mines : * * * and there were brought thence to London “ the same yeare of siluer fined and cast in wedges 700 four pounds, three shil- “ lings, and one penie weight. In the 25 yeare of his reigne, there were three “ hundred and fourtie miners brought again out of the Peake into Deuonshire, “ and out of Wales there were brought also 25 miners, which were all occupied “ about those siluer mines, beside others in the selfe countrie of Deuonshire, and “ other places.”— Holinshed’s Chronicles (Edit. 1807), n. p. 545. “ Silver formerly was found in great plenty in the parish of Combe-Martin “ (Miners being fetcht out of Derby-shire for the digging- thereof) in the Etaign “ of King Edward I.”— Fuller, Worthies of England (Edit. 1811), l. p. 270. “ The lead mines of Combe Martin were formerly celebrated for their silver.” Polwhele, History of Devonshire, i. p. 301. “ From the lead mines of Beer Alston a large quantity of silver has been “ extracted. The produce of one vein averaged about 70 ounces ’ (0-002142) “to the ton of lead. Another vein * * * produced 170 ounces ” (0 005102) 110 W. J. Henwood, on the Mining however, much more plentiful in them; and the “ of silver in. the ton of lead. * * * During six weeks the silver extracted “ from lead procured here exceeded six thousand ounces.” Rees, Cyclopaedia, xxxn. Article Silver. “ The mines of Beer Alston and Beer Ferrers are remarkable for the length “of time for which, at different periods, they have been worked, and for the “ quantity of silver which they contain; the silver in each ton of lead being “ from 80 to 120 ounces ” (0 002448 to 0-003672 its weight). “ Wheal Betsy lead mine in Mary Tavy, which had been worked about 80 “ years ago, was re-opened about 1806. * * * The quantity of pig-lead ob- “ tained from it is now between 300 and 400 tons in a year, and the silver from “ 4,000 to 5,000 ounces, although a ton of the lead yields only 12 ounces ” (0-000367). “ The proportion of silver in the ore of “ a lead and silver mine at Newton “ St. Cyres * * * is said to have been 30 ounces to the ton ” (0-000918). Lysons, Devonshire , i. p. cclxxxviii. Lead from shallow parts of the Tamar Mines contained about (one hundred and forty-five ounces per ton) 0 004437 its weight of silver; but from deep levels (galleries) it afforded from (thirty-five to forty ounces) 0-001071 to 0-001224 only.— Percival Norton Johnson, Esq., F.R.S., F.G.S., &c. MSS. Devonshire 1856. Proportion of Silver in Lead-ore. Lead. Tamar Silver Lead .... 0-001306 0-002312 South Tamar Consols .. 0-001407 0-002381 Boringdon Consols .... 0-000871 0-001453 East Tamar ... 0-000793 0-001076 Huel Exmouth &; Adams . 0-000380 0-000612 West Collacombe . 0-000318 0-000612 Frank Mills ........ .. North Huel Friendship .. 0-000198 0-000372 Park, Huel Carpenter , Whitleigh , Silver Brook, & Wood Mine . 0 000100 0-000146 1857. Proportion of Silver in Lead-ore. I Lead. 0*001114 0 002079 0*000788 0*001882 0-001102 0-001714 0-000523.0-000949 0-000129 0-000214 0-000059 0 000112 0-000007 OOOOOIQ Mr. Hunt, Memoirs of the Geological Survey of Great Britain .— Mineral Statistics. 1856, p. 30 ; 1857, p. 32. “ Silver found in Cornwall unmixed (I mean free from tin, copper, or lead) I “ have never seen but once, and that was found native, about the bigness of a “ walnut (of which I have part), in Huel-cock, a copper-work in the Parish of “ St. Just.” Borlase, Natural History (1758), p. 209. “Native silver, dentritic and in elongated octohedral crystals; and also “ capillary native silver on arragonite, have been obtained from Levant, in St. “ Just.”— Mr. Carne, Cornwall Geol. Trans., vi. (1846), p. 48. Mr. Garby, Ibid, vii. p. 87. “ In the vein formerly worked at Huel Mexico the ore appeared * * * as “ insulated masses or nests, and beside native silver, corneous ore (muriate of “ silver) was also met with.”— Dr, Berger. Geological Transactions, i. p. 171. District of Chaharcillo in Chili . Ill chloride of silver abounds in shallower parts of the Huel Mexico in Perran Zabuloe “ produced considerable quantities of rich “ horn-silver; ” and “some fibrous native silver was found in the gossan.” Lysons, Cornwall , ccx. Carne, Cornwall Geol. Trans., i. p. 121. “ About thirty years ago, a lode of silver was discovered near the sea, between “ St. Agnes and St. Michael; and the mine, which was called Huel Mexico, “ produced about £2,000 worth of ore.” C. S. Gilbert, Historical Survey of Cornwall (1817), i. p. 218. Hashleigh, British Minerals , n. p. 19. Pl. xvi. My grandfather was one of the unfortunate adventurers in this, the first, Cornish silver-mine. “ About fifteen years since, a few small bunches of exceedingly rich silver ore “ (particularly horn-silver, or muriate of silver, a very rare production) were “raised in Cubert parish. Many of these pieces were finely crystallized: but “ the most beautiful specimen is in the cabinet of John Williams, Esq., and has “ been represented and described in that elegant work of Mr. James Sowerby, “ the British Mineralogy for 1808.” C. S. Gilbert, Historical Survey of Cornwall (1817), i. p. 219. “ At Herland in Gwinear the silver cross-course between 110 and 142 fathoms “ deep afforded for some distance on either side of the Main (Manor) lode, which “ it intersects, a mixture of galena, native bismuth, grey cobalt-ore, vitreous “ silver-ore, and native silver ; of which about 108 tons were raised. The richest “ mass of silver-ore was found at but two fathoms above the level at which it “ disappeared,”— The Reverend Malachy Hitchins, Phil. Trans., 1801, pp. 159-163. Dr. Berger, Geol. Trans., i. p. 171. William Phillips, Geol. Trans., ii. p. 152. Lysons, Cornwall, ccx. Polwhele, Cornwall , iv. p. 134. C. S. Gilbert, Cornwall, i. p. 218. Carne, Cornwall Geol. Transactions , i. p. 121; ii. p. 113. Rees, Cyclopcedia, xxxii. : Article Silver. Sir H. T. De la Beche, Report on the Geology of Cornwall, Devon, ancl West Somerset, p. 288. The quantities of ore,—the proportions of silver they contained,—and the sums realized by their sale, were :— Date. Weight of ore, 20 cwt.to the ton. How disposed of. Proportion of silver. Price of ore per ton. Amount. 1799. tonscwt.qrs. lbs. £ s. d. £ s. d. Aug. .... 17 10 0 0 Smelted at the mine .. 0-005407 928 6 4 Sold to— „ 20th. 2 0 0 0 Birmingham Co. 0-006120 48 0 0 96 0 0 Sept. 30th. 3 1 2 17 Philip George & Co. .. 0-006334 50 0 0 154 2 6 1800. Jan. 20th. 19 18 0 0 ditto 0-006334 50 0 0 995 0 0 ,, 30th. 1 12 0 0 Joseph Edwards & Co.. 0-006334 50 0 0 80 0 0 Feb. 20th. 3 0 3 25 Riddle & Co. 0-006334 50 0 0 ' 152 8 8 April 5th. 20 5 3 13 Philip George & Co. .. 0-006334 50 0 0 1014 13 3 „ 24th. 6 1 0 0 Riddle & Co. ........ 0-006334 50 0 0 302 10 0 ,, 26th. 12 6 3 0 Philip George & Co. .. 0-006334 50 0 0 616 17 6 }} )> • 0 4 3 7 Birmingham Co. .... 0-021236 Different ^ 42 19 3 average. rates. • l Forward . 86 1 0 6 £4382 17 6 S 112 W. J. Henwood, on the Mining series. The iodide and bromide of silver,—nowhere Forward . 1800. Aug. 5th. 99 Total .. tons cwt. qrs. lbs. £ s. d. 86 1 0 6 21 18 1 15 Philip George & Co. .. 0-006334 50 0 0 1 12 0 0 Edwards & Harvey .. 0-006334 50 0 0 6 4 17 Ditto Litharge. 115 15 3 0 £ s. d. 4382 17 6 1095 19 0 77 5 6 93 6 0 £5649 8 0 From the MSS. of Alfred Jenkin, Esq., the Lord's Agent. After a while the works were abandoned; but they were resumed in 1825, and the Silver cross-course, again wrought, afforded small quantities of silver-ore at a greater depth ('Cornwall Geol. Trans., v. Table XXXIV viz.— Date. Quantity of ore. Proportion of cwt. qrs. lbs. silver. Feb. ... . 4 2 0 ..... .... 0*012546 A up'. ... . 7 1 0 . .... 0-001714 . 4 2 0 _ _ 0-004162 . 2 2 0 . .... 0-006334 From the MSS. of Edward Michell, Esq, Mayor of Truro. At the adjoining mine, “ Huel Alfred, in 1813, some native silver was found, “ appearing as if plated on the copper ore ; but in so small a quantity as not to “ be worthy of notice.”— Carne, Cornwall Geol. Trans., i. p. 123. “ Native silver is accompanied by red, grey, and black silver ore, in Huel “ Alfred.— William Phillips, Mineralogy (3rd Edit.), p. 285. “ Huel Alfred, in Phillack, has produced native silver in green carbonate of “ copper.”— Michell, Manual of Mineralogy (Truro, 1825), p. 20. “ Huel Ann, in Phillack, furnished, in 1814, a small bunch of blackish grey “ silver ore containing a great deal of arsenic and spathose iron, and accompanied “ by native silver, at the sixty-five fathoms level, in an east and west copper lode. “ In the seventy-five fathoms level, the silver ore appeared in the midst of the “ copper lode, as a separate lode, from two to five inches wide. * * * Some fine “ specimens of fibrous native silver were found in this level; but these, as well “ as the ore, proved of very short duration.” Carne, Cornwall Geol. Trans., i. p. 124; ii. pp. 105, 120. “ Huel Ann has produced native capillary silver, with surprising fineness of fibre, “ in tin-white and grey cobalt, and grey silver in arsenical pyrites.” Michell, Manual of Mineralogy , p. 20. “ In Dolcoath, in 1810, some grey silver ore intimately united with cobalt ore, “ together with a little native silver, were found in the sixty fathoms level in the “ copper lode, very near a small cross-course.”— Mr. Carne, Cornwall Geol . Trans., i. p. 122. Wm. Phillips, Mineralogy (3rd Edit.), p. 288. Michell, Manual of Mineralogy , p. 20. “ In the Entral South lode, at Dolcoath , much native silver, as well as vitreous “ and red silver ore, were mixed with galena, blende, and with still larger quan- “ tities of iron and copper pyrites, quartz, and slaty clay.” Cornwall Geol Trans., v. p. 66, Table. L. District of Chanarcillo in Chili . 113 common—are in Chanarcillo peculiar to this formation. The silver ores sol Date. 1833. Nov. 23rd. .. d from this pa Quantity of ore. 20 cwt. to the ton. tons cwt. qrs. 1 15 1 irt of the mine Proportion of silver. 0*011995 were:— Price of ore per ton. £ s. d. 99 10 6 Amount. £ s. 175 8 d. 2 >> 1 0 3 0-002478 16 13 10 17 6 4 1834. July .... 4 4 0 0-008476 69 1 5 290 2 0 ,, • • • • 3 3 0 0-004039 30 11 0 96 4 6 Aug. 21st 4 16 0 0-006273 49 18 1 239 10 8 1835. Jan. 6th .. 3 3 0 0-007650 61 13 4 194 5 0 99 * * 4 19 0 0-005202 40 9 6 200 7 1 » • • 1 13 0 0-003978 29 19 0 49 8 4 12th .. 2 12 2 0-005875 46 9 0 121 18 9 99 • • 4 0 1 0-002846 20 2 5 80 14 6 1836. Jan. 12th 1 10 3 0-002968 20 19 0 32 4 2 99 0 12 2 0-006334 50 8 0 31 10 0 99 0 4 1 0-049909 430 3 4 91 8 2 Nov. 23rd 1 12 3 0-002111 13 6 8 21 16 8 99 2 4 2 0-001928 11 18 1 26 9 8 99 0 17 0 0 003764 27 19 7 23 15 7 99 0 18 0 0-000734 1 9 6 1 6 6 >> 0 11 0 0-010220 84 5 9 46 7 1 39 17 2 £1740 3 2 beside which, above one thousand three hundred Pounds were realized from ore smelted at the mine. Entral South lode has therefore yielded more than three thousand pounds worth of silver.— From, the MSS. of Captain Charles Thomas, Manager of Dolcoath. “ The noble family of Basset, the proprietors of the land, preserve as an heir- “ loom a splendid piece of plate made of silver raised at Dolcoath; which was “ presented to the late Lord De Dunstanville by the adventurers in that mine, as “ a testimony of their gratitude for his liberal relinquishment of the Lord’s dues , “ whenever the poverty of the concern rendered an increased outlay necessary.” Cornwall Geol. Trans., v. p. 66, Note. The silver-ore of North Dolcoath , an adjoining mine, afforded, during 1859-60, 0-003011 its weight of metal.— MSS. of Captain Joseph Vivian, Manager of North and South Roshear , <$fc. Mr. Carne states that at Huel Basset, in Illogan, a small cross-course traversing the lode, afforded, in 1813, vitreous silver-ore, some of which yielded (0*018360 its weight) six hundred ounces of silver per ton, at and within about six feet on either side of the intersection (Cornwall Geol. Trans., I. p. 124) ; and Mr Wm. Phillips observes that silver-ore worth three thousand Pounds was obtained there. Mineralogy (third Edition, 1823), p. 236. Mr. Martyn, the sole survivor of those who at this time and long afterwards were agents at Wheal Basset, says that during his connexion with that mine, silver-ore was discovered but once,—that the quantity was very trifling,—the quality such that for several years no purchaser could be found,—and at length 114 W. J. Henwood, on the Mining Both the lodes , and the layer of rock (the Manto) it realized only a small sum. He adds that there was neither record nor tradition of any similar discovery having been made previously. The late John Williams, Esq., of Scorrier House, had the entire direction of Wheal Basset during this period. His account books, examined in aid of this enquiry, fully confirm the accuracy of Mr. Martyn’s recollection ; and show that the silver-ore raised in 1813 was not disposed of until 1827, when it was sold for £15 : 12: 4 only. Silver-ore is thinly dispersed through siliceous earthy brown iron-ore (gossan) in the shallower parts of Treskerby near Redruth. In 1827 a parcel of it realized £15 : 14: 4. At the same time a smaller quantity of similar ore was sold from the adjoining mine of North Dozens for £3 : 4:9. William Williams, Esq., of Tregullow. MSS. The ancient mine of Bal-clhu, in Kea (Davies Gilbert, Cornwall , n. p. 302), affords enormous masses of the same ore; which have been, from time to time, largely wrought for the scattered particles of silver-ore they contain. “ Huel Duchy in Calstock * * * one of the principal silver-mines * * * has “ already produced about £4,000, and promises to be yet more profitable.” Lysons, Cornwall, ccx. “ Wheal Duchy in Calstock (discovered in searching for copper) has been “ worked with success. The whole lode is from 6 to 12 inches wide—the part “ containing silver from 1 to 4. It runs E. & W.,the direction of other similar “ veins in the neighbourhood. Some of the ores contain from 60 to 70 parts in “ 100” (0’6 to 0*7) “ of pure silver. About £5,000 worth of silver, a year or “ two ago, had covered the expense of the undertaking in its early stages.” Polwhele, Cornwall, iv. (1816), p. 134. “ Some silver works are still kept open at Calstock, by the name of Wheal “ Duchy , from which the cup presented to the Duke of Cornwall, in the year “ 1812, by Benjamin Tucker, Esq., was extracted.” C. S. Gilbert, Cornwall, i. p. 219. “ At Huel Duchy, near Callington, in a lode inclining to the north-east and “south-west, and from one to three feet wide, in which the adventurers were u searching for copper, detached lumps of silver-ore, and small bunches of native “ silver were found at the adit. In the ten fathoms level, there was a regular “ course of silver ore, accompanied by native silver, for nearly three fathoms “ in length, yielding above £200 worth per fathom. This was its richest part. “ In the twenty fathoms level, some native silver, and bunches of silver ore were 11 found, but the lode had here declined in value. In the next deeper level the “ silver was exhausted. The ore consisted chiefly of red and grey silver and black “ oxydof silver.—The value of the silver produced was about £3,000.” Carne, Cornwall Geol. Trans., i. p. 122. Michell, Manual of Mineralogy, p. 21. After this the mine remained many years unwrought; but in 1833 it was re¬ opened under the name of Wheal Brothers. De la Beche, Report , p. 613. Cormoall Geol. Tra?is., v. p. 140 ; Table XCIII, District of Chanarcillo in Chili . 115 which deflects them from their ordinary dip in the “Portions of argentiferous earthy brown iron-ore (silver gossan) left by the “ former adventurers in shallow parts of the mine, were now extracted and sold “ for between £150 and £200 per ton. “ So greatly does the ore differ in quality, that some parcels of it brought no “ more than £2, and others,—containing 0-059976 their weight of silver,—as “ much as £500 per ton in the market.”— Captain Knott, MSS. “ At the 30-fathom level masses of native silver, weighing many pounds each, “ occurred in a part of the lode which was worth from £500 to £600 per fathom. “ But great part of the ore when brought to the surface contained only from “ (eight to ten ounces) 0*000245 to 0*000306 its weight; although when (dressed) “ prepared for sale it yielded (sixty ounces per ton of ore) 0*001836 its weight “ of silver.” —Perciyal Norton Johnson, Esq., F.R.S., F.G.S., &c., MSS. “ Wheal Sisters, opened also in 1833, on an eastern part of the same lode; “afforded ore which, resembling for the most part that of Wheal Brothers , con¬ tained from 0*00459 to 0*07344 its weight of silver. Portions of it were, “ however, mixed with from 0*15 to 0*2 their weight of lead. Small quantities “ of the silver-ore were sold at twenty shillings a pound; and some parcels found “ a market at from £400 to £500 per ton, but the ordinary price was between “ £30 and £50.”— Captain Knott, an Agent of the Mine, MSS. Wheal Saint Vincent yielded great quantities and many varieties of silver-ore from a parallel lode south of that wrought at the same time in the neighbouring mine of Wheal Duchy; but, no longer affording profit, it was closed in 1824. If accounts of the produce still exist they are inaccessible. In 1835 the works, then named the East Cornwall Silver Mines, were re-opened, but, after an unsuccessful trial of about two years, they were again abandoned. During that period they yielded the undermentioned ores:— Date. Weight of ore. Proportion of Tons. cwt. qrs. lbs. silver. 1837. Sept. 0 17 1 0 0*002708 ,, . 0 6 3 0 0*009118 „ . 0 4 0 14 0*030263 1 8 0 14 Edward Michele, Esq., Mayor of Truro, MSS. “ The same mine was opened a third time in 1848, under the name of Wheal “ Langford. Silver-ore becomes less and lead-ore more abundant as the mine is “ deepened ( Postea , p. 119). For several years the ore afforded from 0*001224 to “ 0*060466 its weight of silver, and its price ranged between £10 and £550 per lC ton. In June, 1855, Tons 2 : 6 : 2 : 6 (sold at £509 per ton) realized “ £1184 : 15 : 9.” —Captain Knott, an Agent of the Mine, MSS. “ Wheal Mexico, wrought to an inconsiderable depth on an eastern part of the “ same lode, during 1847-8,—afforded the chloride of silver largely mixed with “ slaty clay, granular quartz, and the carbonate of iron. Some portions of the “ ore contained 0*001224, others 0*026316, their weight of silver. The prices T 116 W. J. Henwood, on the Mining first limestone, contain native silver largely mixed “ generally ranged from £5 to £200 per ton ; but small quantities, free from “ impurity, were sold at £2 : 10 : 0 per (Avoirdupois') pound.” Captain Knotj, Manager of the Mine , MSS. “ About four miles to the south-east of Callington is a silver mine * * * “ situate in a rock of killas or chlorite slate. The vein was first worked for “ copper, but native silver and lead-ore were discovered in it. The mine is called “ Huel Jewel: the thickness of the vein rarely exceeds three or four inches. In “ many of the cavities were found a considerable quantity of capillary native “ silver, with galena, red silver-ore, and sulphuret of silver. The ores were ex- “ ceedingly rich, and promised * * * an ample recompense to the adventurers.” Rees, Cyclopcedia , xxxn. (Silver.) “ In Willsworthy mine, on the border of Devon, the lode is about twelve inches “ wide, bearing N.N.E. & S.S.W., and underlies two feet and a half per fathom “ to the south. In the ten fathoms level, a vein of white and amethystine quartz “ divided the lode ; between this vein of quartz and the lower, or northern wall “ of the lode, was found a vein of rich arsenical cobalt ore combined with native “ capillary silver, in a ferruginous matrix, from three to six inches wide. The “ space between the vein of quartz and the higher, or southern wall of the lode, “ was occupied by a vein of rich yellow copper ore, from six to nine inches wide. “ The silver continued about two fathoms in length. The copper was not so “ soon exhausted. The specimens of native silver from this mine have eclipsed “ all that have ever before been found in Cornwall, both in size and beauty.” Carne, Cornwall Geol. Trans., i. p. 124. Phillips, Mineralogy (Third edit.), p, 285. Michell, Manual of Mineralogy (Truro, 1825), p. 21. Greg & Lettsom, Manual of Mineralogy (London, 1858), p.'240. Between Marazion and Penzance West Wheal Darlington was wrought, in search of copper-ore, to nearly forty fathoms from the surface and some twenty- five below the sea, in closely-jointed, deep blue, homogeneous clay-slate; on a lode, which,—bearing 10°-20° N. of E. and S. of W., and composed of quartz, quartzose slate, and iron pyrites,—unexpectedly yielded large masses of native silver, mixed, sometimes, with galena, and, less frequently, with copper pyrites. The following columns afford particulars of the proceeds:— Weight of ore, Date. 20 cwt. to the ton. Proportion of Price of ore Amount. tons cwt. qrs.lbs. Silver. Lead. Copper. per ton. 1852. £ S. d. £ s. d. Nov. 9th 0 14 0 0 0-032100 • • • » 256 5 0 179 7 6 55 0 18 3 0 0-008048 • • • • 71 12 0 67 2 6 55 1 4 0 0 0-001805 • • • • 9 5 0 11 2 0 55 0 9 0 0 0-003825 0-322500 33 10 0 15 1 6 1853. Jan. 31st 3 1 1 0 0-004957 • • * < 29 1 0 88 19 2 55 4 19 1 15 0-001224 • • • • 7 12 6 37 17 7 Mar. 29th 1 18 3 20 0-002815 0-630000 38 16 8 75 11 10 May 10 th 0 4 3 14 0-060282 • • • • 523 15 0 127 13 2 55 3 9 2 1 0-007497 • • • • 51 2 0 177 12 0 55 1 5 0 16 0-003978 • • i • 16 0 0 20 2 3 55 1 18 3 17 0-003672 • • • • • • • • 25 5 0 49 2 2 55 1 9 1 26 0-002142 • • • • 15 10 0 22 16 9 Forward . 21 13 0 25 872 8 5 District of C/iaharcillo in Chili 117 with the chloride and chloro-bromide of silver; and, 1853. tons cwt.qrs. lbs. £ s. d. £ s. d. "Forward . 21 13 0 25 Q r July 19th 0 5 2 22 0-076500 • • • • • • • • 634 15 0 O / L 180 O 15 0 10 >> 3 7 0 15 0-005141 • • • • 36 12 0 123 1 10 y y 2 10 2 20 0-004896 • • • • 32 4 0 81 11 10 Aug. 18 th 0 11 0 19 0-030294 • • • • 305 0 0 170 6 10 yy 1 2 0 21 0-001867 0-572500 20 4 0 22 8 1 yy 3 4 0 11 0-002815 • • • • 19 12 0 62 16 2 yy 9 2 0 5 0-002509 • • • • 13 6 0 121 1 2 yy 4 6 1 24 0-001254 • « • • 6 10 0 28 2 3 yy 1 10 2 21 0-000612 • • • • 3 0 0 4 12 0 Sept, 28th 0 8 2 11 0-112118 • • • • 1075 5 0 462 5 2 yy 2 8 0 11 0-004039 • • • • 35 15 0 85 19 6 y> 3 18 3 12 0-001867 • • • / 10 15 6 42 9 7 yy 7 9 1 10 0-002867 • • • • 19 0 0 141 17 5 yy 3 16 1 5 0-002509 • • • • 12 15 0 48 12 8 Nov. 9th 0 9 3 2 0-039351 372 15 0 182 0 11 yy 11 14 3 0 0-001254 • • • • 8 1 6 94 15 7 « yy 10 5 3 0 0-001560 • • • • 7 18 6 81 10 6 yy 7 5 3 22 0-001060 • • • • 5 5 0 38 6 3 y y 2 0 2 0 0-000627 • • • • 2 0 0 4 1 0 Dec. 20th 2 0 0 0 0-002172 , , yy 6 0 0 0 0-001224 • • • • , _. yy 10 0 0 0 0-000765 • • • • - . . j yy 15 0 0 0 0-000612 • • • • i yy 5 0 0 0 0-000551 • • • • MM _ y y 2 10 0 0 0-000306 • • • • - 1854. Feb. 22nd 2 7 0 25 0-002509 • • * ♦ 24 10 0 57 17 0 yy 17 7 0 21 0-001163 • • • • 7 5 0 125 17 1 April 11 th 5 5 0 0 0-001652 • • • • 16 10 10 86 12 6 May 25th 1 13 2 12 0-002540 • • • • 18 5 0 30 13 3 yy 7 8 1 6 0-001224 • • • • 6 15 0 50 1 0 July 19th 0 16 2 12 0-143820 0-335000 65 0 0 53 19 4 yy 0 12 1 18 — • • • • 22 15 0 14 2 4 yy 4 2 1 16 — • • • • 7 16 0 32 2 9 yy 1 17 0 7 -- • • • • 4 5 0 7 17 6 Aug. 30th 0 17 3 27 0-000964 0-436250 20 2 0 18 1 8 yy 5 18 2 0 0-001224 • • • • 12 17 2 75 3 6 yy 2 3 1 14 0-000918 • • • • 0-060000 11 4 8 24 17 3 Nov. 15th 4 1 1 0 0-001102 • • • • 6 0 0 24 7 6 yy 2 14 3 0 0-000612 • • • • 2 12 4 7 3 4 Dec. 31st 52 4 0 0 0-000306 • • • • >> 18 19 1 0 0-000409 • it* [ 1 0 0 150 18 0 yy 79 14 3 0 0-000153 • • • • j 1855. Feb. 14th 0 0 0 7 • • • • 5120 0 0 16 0 0 24th 2 3 1 0 0-001316 0-290000 12 10 0 27 0 7 yy 1 5 0 0 0-000153 • • # • 0-062500 5 18 10 7 7 6 }> 2 0 3 0 0-001163 • • • • • • • • — — of ore | 309 3 1 1 ( Higliest Pyice °f ^ £5120 0 0 sold. .J J ore ton, $ unsold. 42 10 3 0 ] Lowest ,, ,, 10 0 Average „ ,, 11 16 8 .. £3659 5 1 Value of ore sold. For this account, compiled from the Mine-books, I am indebted to W. J. Rawlings, Esq., of Hayle. 118 W. J. Henwood, on the Mining more sparingly with vitreous and red silver; but they Arsenical silver-ore has been discovered in quartz near Camborne ; and native silver in copper pyrites at Crennis, near St. Austell,—in ( gossan ) quartzose earthy brown iron-ore at the Fowey Consolidated Mines near Fowey,—-and in galena at Wheal (Providence) Tremayne near Hayle ; in each of these instances the quantity has been very small. Michell, Manual of Mineralogy (Truro, 1825), p. 21. Garby, Cornwall Geol. Trans,, vu. p. 88. Greg & Lettsom, Manual of Mineralogy (London, 1858), p. 240. “ Dr. Woodward (vol. ii. page 29) gives a very advantageous character of the “ ore found at Guarneck, in the parish of St. Allen near Truro. It was a blue “ lead ore, very rich in silver, perhaps beyond any in England besides : * * * “ one of the proprietors, and some of the workmen, averred, that a ton of it “ yields 140 ounces (0*004284 its weight) of silver. “ The ore which is poor in lead, does sometimes yield silver plentifully.” “ Borlase, Natural History, pp. 210, 211. “ In the Garres in St. Allen the ore when last wrought was so rich in silver, as “ to yield one hundred ounces to one ton of lead ” (0-003060 its weight). Pryce, Mineralogia Cornubiensis, p. 58. “ Guarneck near Truro, now called the Garres, was wrought about 1720, when “some of its lead produced” (0-003060 its weight) “ one hundred ounces of “ silver per ton. In 1814 it was again set at work, and continued two years. “ During this period it produced eight hundred tons of silver lead ore, containing “ thirteen parts in twenty of lead, and the lead yielding seventy ounces of silver “ per ton.” The proportion of lead in the ore was 0*650000 its weight; and ,, silver in the lead ,, 0-002142 ,, Carne, Cornwall Geol. Trans., i. p. 120. Polwhele, Cornwall, iy. p. 134. C. S. Gilbert, Cornwall , i. p. 259. Rees, Cyclopccdia (Silver), xxxii. Hitchins & Drew, Cornwall , i. p. 624. Phillips, Mineralogy (3rd edit), p. 335. Michell, Manual of Mineralogy , p. 13. “ Silver united with lead in the state of galena is found in the mine of Huel “ Pool.”— Klaproth, Mineralogical Observations on Cornwall , p. 30. Berger, Geological Transactions , i. p. 171. Lysons, Cornwall , p. ccix. C. S. Gilbert, Cornwall , i. p. 259. Weight of ore, 20cwt. to the ton. Purchasers. Proportion Price of ore Amount. tons cwt.qrs.lbs. of lead. per ton. £ S. d. £ s. d. 1 14 2 0 Rob. Michell & Son. 0*750000 95 10 6 164 15 6 0 2 0 0 Ditto 0*450000 74 3 4 7 8 4 0 1 3 16 Trustees of Treffry > Estate ..f 0*750000 435 10 6 41 4 4 0 14 3 19 Ditto 0*650000 135 0 0 100 14 1 0 4 3 11 Ditto (Slimes) 7 10 0 1 16 4 1 9 0 12 Rob. Michell & Son. 0*650000 333 7 6 485 3 6 2 19 0 1 Ditto .. 0*612500 97 0 0 286 3 10 7 6 1 3 £1087 5 11 Assays show the silver contained to have been (3868 troy ounces per ton)— 0*016189 the weight of ore, or 0*024590 „ lead. Account Books of the Mine. “ In the island of Sark no silver ores, except a few crystals of ruby silver, il occur uncombined with lead in the western part of the Sark mine ; but east- “ ward the lode contained rich deposits of silver ores without any lead. The “ muriate of silver was imbedded in gossan, and mixed with the blue and green “ carbonates of copper near the surface; but at, and for thirty fathoms below, “ the adit (sea level) it was replaced by black sulphurets of silver and copper, “ mixed with disintegrated iron pyrites; and still deeper the sulphuret of silver “ was found combined with the sulphurets of copper and antimony. In the “ deeper levels west the lode afforded sulphato-tricarbonate of lead, sulphuret of “ lead, super-sulphuret of lead, black sulphuret of lead (rich in silver), antimon- “ iferous galena, and granular galena which contained,— v Lead in the ore. Silver in the ore. Silver in the lead. 0*200000 to 0*850000 .... 0*000096 to 0*000384 — 0*000019 to 0*000326.” Prince, Cornwall Geol. Trans., vi. 102. * M. Domeyko, Annales des Mines , 4me Serie, ix. p. 434. 122 W. J. Henwood, on the Mining It has been already said # that the lodes —passing un¬ interruptedly downward, through three strata of lime¬ stone (a. c. e.) alternating with two of greenstone (b. d .), and partaking in turn the nature of every rock they traverse—are productive in the limestone alone. Much smaller than similar deposits of tin, lead, and copper elsewhere,f the masses—(in Cornish mining language rather bunches than courses J)—of rich silver-ore they afford,—as well as the congenial earthy matrix sur¬ rounding them, which is severed merely by unkindly hornblendic ingredients in the greenstones,—maintain —in obedience, perhaps, to a common influence—one uniform shoot § or inclination throughout the three limestones (Pl. II.). This slope—subordinate to that of the granitic formation between Chanarcillo and Pabellon on the north ||—-is more rapid than that of either the strata or their several beds; and, like it, is towards the south-west. * Ante, pp. 69, 70. + Borlase, 'Natural History, PI. XVIII. Pryce, Mineralogia Cornub., PI. IV. Heron de Villefosse, La Richesse Mineral, PI. V. VI. VII. XII. XIII. XIV. XV. XVI. XVIII. XIX. XX. Thomson, Travels in Sweden , PI. X. Williams, Geological Transactions, iv. PI. 7, fig. 3. Weaver, Geological Transactions , v. PI. 12. Clarke, Travels (Edit, 1824), x. p. 521. Burr, Practical Geology , PI. VIII. IX. De la Beche, Report on Cornwall, fyc., PI. VIII. IX. Henwood, Cornwall Geol. Trans., v. PI. I. fig. 9;—PI. IV. fig, 4. Foster & Whitney, Report on the Copper-Lands of Lake Superior, PI. VII. Whitney, Metallic Wealth of the United States, PI. I. II. III. Pernollet, Annales des Mines, 4me Serie, x. PI. 5, fig. 9;—PI. 6, fig. 7, 10, 15, 17- Encyclopaedia Britannica (8th Edit.), xv. p. 224, fig. 3. J “ When the lode consists either entirely, or for the most part, of ore, it is “ provincially called a course of ore; and, if the metallic substances appear in “ short and unconnected masses, they are designated bunches of ore.” Cornwall Geol. Trans, v. p. 210. § Cornwall Geol. Trans., v. pp. 41, 54, 87* * * § , 129, 193;—vi. p. 146. || Annales des Mines , 4me Serie, ix, PI. IV. District of Chanarcillo in Chili . 123 When the lodes of Chanarcillo—whilst they traverse the first and second limestones, — are viewed either longitudinally or transversely, the rich portions of some confront the poor parts of others ; although meridional lines,—to which their directions are oblique,—intersect the productive parts of all.* The extent and (approximate) produce of the prin¬ cipal mines wrought in Chanarcillo during the five- and-twenty years ending with 1856, have been,')'— Mine. Extent, fathoms. Formation. Produce (approximately). Manto do Ossa ... ... 94x48 ... Manto . > Colorada lode .. Waring"s lode • • • J • £400,000 Valenciana . ... 47x43 ... Manto . Colorada lode .. • • • - 300,000 Waring's lode *•* , Forward ... £700,000 * Carne, Cornwall Geol. Trans., hi. p. 78. See also Ibid , v. pp. 87 *, 215, 233; and Ante , p. 16. f Edwin Pkice Waeing, Esq., of Neath, Manager of Colorada & Desempeno, MSS. i 1*24 W. J. Henwood, on the Mining Mine. Extent, Formation. Produce fathoms. (approximately). Forward . £700,000 Esperanza. 141x39 ' | Bolaco . 94x48 i J Waring's lode ... | >* 200,000 ] | (Bolaco lode . J i Colorada . 85x46 I • Waring' 1 s lode ... Candelaria lode ... J ► 600,000 Desempeno . 57 x 64 Waring's lode ... j J 120,000 San Francisquito ... 48 x 58 200,000 Bocona . 29 x 39 60,000 San Jose . 65 x 51 700,000 San Francisco viejo. 94 x 48 ] 800,000 San Francisco nuevo* 85 x 48 j Delirio . 88 x 75 300,000 Constancia . 93x42 160,000 San Bias . 93X42 100,000 Descubridora . — X — 2,000,000 Mina de Carvallo ... — X — 200,000 £6,140,000 Beside these there are several smaller mines of which it is not easy to ascertain the produce. (D) (1.) Several cross-veins coincide in direction with two series of the joints;*' and traverse, like them, both the rocks and lodes of Chaharcillo. They are, Mine. Cross-vein. Direction. Manto de Ossa . Great Flucan . Colorada .... Cross-vein .... San Jose .... Northern Flucan Southern Flucan . 31°E.of S. & W. of N. . 25° S. of E. & N. of W. Eastward 30° E. of S. & W. of N. Westward 5° W. of S. & E. of N. . 30° E. of S. & W. of N. San Francisco viejo .... Flucan 28° E. of S. & W. of N. Dip. N.E. N. N.E. E. N.E. N.E. * Ante, p. 74. District of Chaharcillo, in Chili . 125 The cross-vein , intersected at a depth of fifty-five fathoms in Colorado, extends, however, neither upward to the surface, nor downward to the first hornblendic formation.* (2.) Their inclination towards the north and east is opposite, as well to the nearest slope of granite,t as to the strata £ and ore-shoots in the lodes, § all which dip to the south and west. (3.) The Great Flucan is, at the Manto de Ossa, as much as eleven fathoms, whilst the cross-vein in Colorado is no more than a foot, in width. The other flucans, —of intermediate dimensions,—usually average from ten to twelve feet. (4.) The cross-veins, like the lodes, resemble the rocks they traverse, in mineral composition, and are cal¬ careous in the limestone, but hornblendic in the green¬ stone series. Generally much softer than the strata, and sometimes composed almost wholly of clay, they are divided by many longitudinal joints,|| of which the usually glossy sides are often deeply though irregu¬ larly furrowed, with highly inclined undulating striae.^ Their stony ingredients are however more crystalline than those of the lodes . * Cornwall Geol. Trans., v. p. 381, f Cornwall Geol. Trans., v. p. 277. Ante, pp. 71-74. X Ante, pp. 71-73. § Ibicl, p. 123. Cornwall Geol. Trans., v. pp. 259-261. || “ One of the most remarkable features in the structure of cross-veins is the “ prevalence of joints. Owing to this prevalence the cross-veins have generally “ more distinctly marked walls or boundaries than the lodes. The same structure “ is, moreover, so common in the vicinity of cross-veins, that the rock on both “ sides often, fo rseveral fathoms, consists as it were of alternate veins of quartz “ and of the adjoining stratum.— Cornwall Geol. Trans., v. p. 260. % Ante, p, 13. \ 126 W. J. Hen wood, on the Mining Near the Manto de Ossa many small drusy hollows in the Great Flucan unite to form an irregular cavern of more than forty-five fathoms long. # The strata maintain the same respective levels on opposite sides as well of every lode f as of every cross¬ vein in Chanarcillo, except at San Francisco viejo; but there,—as already mentioned,J—each formation is on the south-west (foot-wallJ, about twenty-one fathoms higher than its counterpart on the (hanging- wall) north-eastern side of the flucan. (a .) Some of the lodes intersect others;—but, with one exception only,—they are all intersected by the cross-veins. * Ante, p. 89. f Ibid, p. 87. § Ibid, p. 71. District of Chanarcillo in Chili . 127 x 128 W. J. Hen wood, on the Mining (1.) Chanarcillo thus presents five contacts of differ¬ ent lodes ;*—• in one of which two lodes unite ; » a second, „ one lode simply intersects another ;— „ a third ,, one „ heaves the other to the 1 , , .. „ (R.) right-hand ^ g and the remaining two lodes heave other two to l greater ano-le. the (L.) left-hand J (2.) It exhibits also fourteen intersections of lodes by cross-veins ,\—- at each of which the lode is heaved; all these heaves are to the.. (L.) left-hand ; but thirteen of them are towards the... (G. A.) greater angle ; whilst one only is „ ... (S. A.) smaller „ . But though the heaves of different lodes by the same cross-vein are not, in all cases, towards like angles; they are—in Chanarcillo at least—always to the same hand.J * In Cornwall and Devon twenty intersections of lodes by other lodes of similar composition, exhibit— six (30 per cent.) simple intersections,— nine (45 five (25 nine (45 five (25 a » ) heaves to the right-hand, and— ) „ ,, left-hand: ) ,, towards the (S. A.) smaller angle, and— ) ,» „ (G. A.) greater angle. Cormoall Geol . Tracis., v. p. 289. f Of 233 intersected lodes in Cornwall and Devon,— 108 are traversed by (cross-courses) quartzose, and 125 by (flucans) clayey cross-veins. by cross-courses , by flucans. if it it ii heaved towards the (G. A.)— greater angle (S. A.)— a 31 or 28-7 per cent., 22 or 17*G per cent. 48 >> 44*4 a 69 „ 55-2 99 29 99 26*9 a 34 „ 27-2 99 64 9) 59*3 99 88 ,, 70*4 99 13 99 12*0 99 15 „ 12-0 99 • Cornwall Geol. Trans.. > v. pp. 291-2. J u As more than 97 per cent, of the lodes traversed by cross-veins in Cornwall c< and Devon are either heaved in the same direction, or are simply intersected,— District of Chanarcillo , in Chili . 129 Between the extent to which the lodes are heaved by cross-veins , and the magnitude of the angles included at their contact, no relation can be traced in Chanar- cillo; # where heaves , differing widely in extent, attend intersections at nearly similar angles. The cross-vein by which the lodes are heaved furthest is however the largest,f as well as the most highly inclined in the district. (3.) The Colorada lode intersects, but does not heave , a small cross-vein ; £ which is traced, either vertically or horizontally,§ but a very short distance. (4.) Each of the five strata on one side corresponds exactly both in thickness, and — with but a single “ whilst less than 3 per cent, are heaved in opposite directions, it may be assumed, “ generally, that the heaves of different lodes by the same cross-vein , are in the “ same direction .—Cornwall Geol. Trans., v. p. 324. *In Cornwall and Devon the relations between the angles included and the results of the intersections are,— Angle included 0° — 10° .... Proportion of intersections unattended by 7leaves. Proportion of heaves. Average distance of heave. 10° — 20° _ • • • • 0*4 per cent. 9 • 1*00 fms. 20° — 30° _ • • • • 3*1 99 9 9 2-55 „ 30°—40 p _ • • • 3-1 99 9 • 4-03 „ 40°—50° .... • • • • 6*7 99 9 9 5-40 „ 50° — 60° .... • • • • 5-8 99 9 9 3-23 „ • • • • O o 1 0 O o • • 11-9 9 m 2*06 „ 70° 80° .... • • • • 20-7 u 9 9 2-65 „ 80° — 90° .... . 8-7 • • • • 2-5’5 99 9 9 271 „ Cornwall Geol. Trans., v. p. 301. “ f In Cornwall and Devon the average distance of the heaves by cross-veins — “ less than one foot wide, is . 2'08 fms., “ more than one foot wide, „ .. 3 83 ,, .” Cornwall Geol. Trans., v. p. 298. % Ante, p. 12. § “ In Cornwall and Devon there are cross-veins * * * which appear only at “ considerable depths ; * * * whilst others extend but short distances horizon- “ tally .”—Cornwall Geol. Trans., v. pp. 311, 312. 130 W. J. Henwood, on the Mining exception # —in level, with its counterpart on the other side of every lode t and cross-vein J in Chanarcillo. These conditions are as incompatible with either a vertical or an oblique movement of the rocks on one side or other of the veins; as they are with motion in any direction, save one parallel to the normal position of the upper and lower faces of each stratum § in the series.|| Nor is it easy,—if indeed it be possible,—to reconcile even this with the unequal displacements (heaves) of different lodes by the same cross-vein .** (— a.) In the exceptional case at San Francisco viejo the strata,—horizontal on both sides of the flucan, —are twenty-one fathoms lower in its north-eastern or upper side (hanging-wall), than their respective coun¬ terparts in its south-western or lower side (foot-wall (Section, PL II.) ; whilst the Waring, Colorada, and Loreto or Dolores Primera lodes ,—all dipping 64°— 78° N.W., are heaved by the same flucan ,—the first two 17*0 the last 16*5 fathoms,—towards the (L. G. A.) left-hand and the greater angle (Plan, PL I.). (— h.) The coincidence of alternating strata which confront,—each its counterpart—on opposite sides of a (cross-vein) flucan, can be deranged by no movement, of one side or other, parallel to their upper and lower faces. But every vein—either vertically or obliquely, * Ante, pp. 71, 72, 125. t Ante, p. 87. J Ante, p. 125. § If the upper and lower planes are not absolutely parallel, any movement co¬ incident with one of them must necessarily displace the other. || Ante, p. 87. H Ante, p. 127. Table III. PI. I. ** Cornwall Geol. Trans., v. pp. 320—322. ft Professor Phillips, Illustrations of the Geology of Yorkshire, Part n., p. iii. PI. xxiv. fig. 16. Ante, p. 72, Note. District of Chaharcillo in Chili. 131 —traversing strata so moved, must of necessity be displaced (heaved) an equal distance in the same direction.* (—c.) A vertical elevation of twenty-one fathoms on the south-western or lower side (foot wall) of the fucan at San Francisco viejo would have produced the difference observed in the level of identical strata on its opposite sides; but such a movement must have necessitated heaves of all lodes dipping—as these lodes dip—64°-78° N.W.— from 9*6 to 5*0 fms. towards the right-hand; whereas the actual heaves are 16*5 „ 17’0 „ „ left- „ .f Hence, neither a horizontal (— b.) nor a vertical (— c .) movement resolves,— even approximately,— this inseparably connected group of phenomena. (— d.) An elevation on one side produces the same displacement as a depression on the other, when oppo¬ site sides (walls) of the (cross-vein) flacan are moved equal distances at similar angles, in contrary di¬ rections/]; The following columns therefore represent dynamical equivalents:— Side moved. Direction of movement. South-western or lower side (foot wall) . Upheaved towards the south-east. North-eastern or upper side (hanging-wall)... Depressed towards the north-west. * Proceedings of the Geological Society of London (1832), i. p. 406. Cormoall Geol. Trans., v. pp. 347, 355. f Proceedings of the Geological Society of London (1832), i. p. 406. Edin¬ burgh New Phil. Journal, xxii., p. 161. Reports of the British Association, vi. Part II. p. 74. Cornwall Geol. Trans., v. pp. 347, 356. Mr. Fox, Report of the Royal Cornwall Polytechnic Society (1836), p. 123. Sir Henry T. De la Beche, Report on the Geology of Cornwall , Devon, and West Somerset , pp. 298-300. X Cornwall Geol. Trans ,, v. pp. 346, 348. 132 W. J. Henwood, on the Mining When several planes, inclined at different angles, are intersected and displaced on another plane oblique to them all, the extent of displacement measured on the line of movement is in eve^ case the same; but at right angles to the dip of each vein so dislocated it is proportional to the angle included between the dislo¬ cated and the dislocating planes. The following theoretical enquiries embrace the direction, inclination, and extent of the motions,* adequate to produce, under different circumstances, some of the displacements observed in the strata and lodes of Chanarcillo. * Cornwall Geol. Trans., v. p. 36G. District of Chaharcillo in Chili 133 CD > -O O . 13 <5 r c3 'cS to. T3 <1 g O N •g H> © © OI r—i ft CD <3 4-> S3 O S3 • H ft o HH *9 cb 6 h4 *q W w o w . "rf a w 'rt o o o W W C3 r - ■ O o •rt n 13 H t—l o w Q 0 0 O 10 O 10 0 0 0 WO 010 >0 to rft CO cb 1-H !>• c b 4h cb 0 cq th T—1 rft Ol t—1 T—1 PI .-H rH rH PI -H r—1 -H3 m ” co co CO CO 00 00 CO CO CO co 00 >P >0 *o f- G x <£ •4h co co cb Ci Ci Ci Ci Ci Ci Ci w CO CO co CO co co CO PI PI PI pi PI PI PI G b to Ip 0 0 0 00 CO co OO O O O .5 c 'p Pi Pi pi ■P 1 rt< rH rH CO CO CO > ■3 2 O O O 0» O O 0 O O O a 0 a 0 t~~ co co CO CO CO CO CO rH rH rH s HH co co CO co CO CO CO rH rH rH rH © • 0Q 3 £5 <+H £ ft-t ft-* £ cr 0 0 ft-! a CD O 0) s > 0 • • • Ip) • • • • • • to • • • g • • « • • • • • • 01 0 • • • • • • • • • • • • • • » • • • CO • • • • • • • • • • -H» S 3 O Q g-o S g ftp § a§ °1 • • • • • • • • • • • JZ5 • • • • • • • • • • • • • • • • • • • • 4 . • « • • • • • • • • • • • » • • • • • • • • -3 • • • Ph • r—4 • • • • • • PH • r-< • • • -H» • • • ft • • • • n • • • c: * 0 0 • • a 0 • a O • a 0 • ^ • • -rH tH • co co • CO 00 ■p-: _ CO CO • CO — ^ • _ t- |r- co (U O h. a £ . CD ** c n O .£> a® • l-H Q c3 . * 0 y-Z .H& J- Pi m5 £ a •H fi C o o pH os jas r S -s "f c3 -I a eS .§ *o s* a s cS • § fc • —« ^-1 S.S* Kfi £ s c3 • N • f—< r 1 o Wfi a. •rl Q ■S 'i s m JO PS •N •N • O I * 5» rS -S E cS .g HH» P CS § O '♦o c5 -*-> c3 0 ^1 SS CO fp O ft m Co E -a a *s s <» ^3 o HO E o cS • o • .ssz; o ft Wft a, O «s cS Vh H-> xn 09 *S *§ s J a & •«d I .S> PS cS as K o 134 W. J. Hen wood, on the Mining This comparison of theory with fact shows that the single rectilinear movement which reconciles these displacements of the strata with those of the Waring and Colorada lodes , whilst all retain their normal inclinations, is incompatible with both the dip and dislocation of the Loreto or Dolores Primera lode. On the other hand a uniform motion sufficient for the conditions of the strata and the Loreto lode is incon¬ sistent with those of the Waring and Colorada lodes* The differences depend neither on minor fractures nor on unequal movements of ruptured strata; for of such there is no trace.f If however the Loreto lode had inclined but a little less than the Waring and Colorada lodes , the very same motion which could displace (heave) them seven¬ teen fathoms horizontally, and at the same time elevate the strata twenty-one fathoms vertically, would also have heaved it sixteen fathoms and a half. * “ In Cornwall and Devon, amongst the recorded examples of several lodes “ intersected by the same cross-vein, there is not an instance in which motion in “ one direction and of the same extent will restore the continuity of every lode so “ intersected. * * * * Any such uniform motion will, in fact, produce in their “ relative positions on opposite sides of the cross-vein greater discordances than “ those which at present subsist.”— Cornwall Geological Trans., v. pp. 370, 380. Edinburgh New Philosophical Journal , xxn, p. 163. f “ If we suppose it possible for the rocks to have been so broken that each lode “ was contained in a different fragment, and that these minute masses had an “ independent motion, in any direction and to any extent required; although such “ movements might, within certain limits, have afforded any desired results; yet “ the motions in different directions necessary to the production of the observed “ phenomena, in different portions, would often have required that the rocks “ should, in some spots, have suffered much compression, whilst large vacuities “ must have been left in others. Had such convulsions ever taken place, traces “ of them must have been conspicuous; —but, in fact, nothing of the kind has “been detected,—even in a single instance.”— Cornwall Geol. Trans., v. p. 383. Edinburgh New Phil. Journal, xxn. (1837) p. 162. District of Chanarcillo , in Chili . 135 But such a constant difference in dip,—though of one degree and a quarter only,— would have made this productive lode the flattest in Chanarcillo ; which is certainly not the case. Whether these discrepant displacements (heaves) of neighbouring lodes result from irregularities of outline in those parts which,—touching opposite faces ('walls) of the same (cross-vein) flucan at different depths,— would coincide if they were confronted; or whether the separated portions of identical lodes have here,—as in Cornwall and Devon,— unlike configurations on contrary sides of the dividing (cross-vein) flucan; the data I possess are insufficient to determine.* The conditions here assumed suit rigid masses only, and are altogether inapplicable to matter in a plastic, viscous, or semi-fluid state. Although the sea is of much larger area than the * “ If those portions of the same lodes on opposite sides of the cross-veins “ which now divide them, had been originally connected and continuous, and “ were subsequently separated by a transverse fracture accompanied by an ele- “ vation or a depression of one of the severed portions, on delineating the line “ of dip of both these segments where they touch the cross-veins , we should “ expect to find them presenting a perfectly or nearly similar outline ; although “ the direction of any movement they had undergone might not allow the cor¬ responding parts to be found at the same levels. PI. XII., Fig. 15, 16, 17, “ 18, 19, 20, present these comparisons; and it will be difficult, if not impossible, “ to imagine that lines so utterly dissimilar, could ever have been united and “ continuous at all parts of their descent, and fractured after they had become “ perfectly hardened .”—Cornwall Geol. Trans., v. pp. 378-9. Y 136 W. J. Henwood, on the Mining land,* * * § water can neither be a principal constituent of the globe, which—of greater specific gravity than any known rock—has a mean density variously calculated at 4*5—6*5 ; f nor can it penetrate far into the crust, for at a depth comparatively smallj it can exist only in the state of vapour. Water infiltrating from above becomes gradually warmed by the strata it traverses; until, at length vapourized, the descending column is balanced. The unequal temperatures prevailing at different depths necessitate a constant interchange of its particles. Further infiltrations must mix with ascending currents specifically lighter and warmer; and — consequently will again reach the surface—at a temperature higher than that of the rocks through which they issue. § This equilibrium between the descending water and * “ The area of the solid land bears to that of the sea the proportion of 100 to 284 ; “ according to Rigaud (Camb. Phil. Trans. , vi. (1837) p. 297, ,, 100 ,, 270 ; “ but according to other authorities, the proportion is. 100 ,, 284.” Humboldt, Edinburgh New Philosophical Journal, xxxix. (1845) p. 108. See also Malte-Rrun & Balbi, Universal Geography (London, 1851), p. 57; Encyclopcedia Britannica (8th Edit. 1856), x. p. 483. t Maskelyne, Philosophical Transactions , lxv. (1775), p. 532. Hutton, Ibid, lxviii. (1778) p. 782; cxi. (1821) p. 283. Cavendish, Ibid , lxxxviii. (1798) p. 520. Playfair, Ibid, ci. (1811) p. 376. De Zach, Uattraction des montagnes et ses effects sur les Jils a plomb ou sur le niveau des instruments d' astronomic (Avignon, 1814), I. p. 351. Carlini, Operations G6ode$iques et Astronomiques pour la mesure d’un arc du Par allele Moyen executees en Pi'emont et en Savoie par une Commission d'offciers Piemontais et Austrichiens, en 1821-22-23 (4° Milan, 1825). Reich, Versuche iiber die mittlere Dichtigkeit der Erde (8vo. Freiberg, 1838), p. 43. Baily, Memoirs of the Astronomical Society, xiv. pp. 90, 247. Airy, Philosophical Transactions, cxlyi. (1856) p. 343. James, Ibid , p. 603. J Babbage, Ninth Bridgewater Treatise, pp. 182, 198. William Hopkins, Phil. Transactions, cxxxn. (1842) p. 43 ; cxlvii (1857) p. 805. Hennessey, Ibid, cxli. (1851) p. 495. Professor Phillips, Quarterly Journal of the Geologi¬ cal Society, xv. (1859) pp. xlv.-l. § “ Water which descends to the volcanic focus is there converted into steam, District of Chaharcillo in Chili. 137 the vapour beneath it, must, of course, occur at depths varying with the quantities and temperatures of the water infiltrating. Much of this infiltration is from rivers, lakes, and the sea, but the greater part is supplied by rain; which,—however abundant in a well-wooded country, —diminishes as the forests are felled, and sometimes ceases almost entirely when they are destroyed. The surface, thus increasingly exposed to evaporative in¬ fluences,* * becomes more and more dry; the springs “ which, rising through fissures into higher regions, meets with atmospheric “ waters which it warms, and with them returns to the surface.” Bischoff, Edinburgh New Philosophical Journal, xxvi. (1839) p. 50. “ The various ramifications of the great adit in the Gwennap mining district “ have an aggregate extent of between thirty and forty miles. It drains a tract “ of about 5,500 acres in area and discharges nearly 1,600 cubic feet of water “ per minute. Rather less than one-half of this stream is collected at the adit, “ which is from 25 to 30 fathoms deep ; the remainder is pumped up from a mean “ depth of about 190 fathoms. Its temperature varies between 60'5° and 68°; “ and is on an average more than 12° above the mean of the climate.” Cornwall Geol. Trans., v. p. 411. * “ The metalliferous mountain of Marmato in the province of Popayan in “ New Granada, is situate in the midst of immense forests. The stream by “ which the stampers are worked is formed by the union of many small brooks. “ * * * The whole environs of the establishment are thickly studded with wood. “ In 1826, when I first visited these mines, Marmato consisted of some miserable “ huts inhabited by a few negro slaves. When I quitted Marmato in 1830, it “ exhibited the most exhilarating appearance. There were now great work- u shops, a foundery for gold, and powerful machines for the reduction of this “ precious metal. All this implies that the wood had been extensively cut down “for the manufacture of the machines, the construction of the buildings, and “ the preparing of charcoal. * * * The clearing had been going on for scarcely “ two years, when it was noticed that the quantity of water, which was required “ for the machines, was sensibly diminished. The volume of water is in fact “ measured by the work which the machines perform ; and trials by guaging at “ different times have likewise proved the diminution of the water.” The town of New Valencia in Venezuela was, according to Oviedo (Ilistoria de la Provincia de Venezuela , 1723) in 1555, half a league from the lake of Tacarigua; which is fed by rivulets rising in the surrounding mountains; but its waters have no outlet. As the population increased, and the neighbouring 138 W. J. Henwood, on the Mining dwindle, and at length—no longer perennial—appear only at intervals after occasional showers. The reciprocal relations of vegetation and water, are perhaps, nowhere more conspicuous than in the valley lands were cleared and cultivated, streams, which had previously fed the lake, were intercepted by artificial channels for irrigation. Their sources, at length, occasionally failed, their beds were sometimes dry for half the year; and the lake—no longer replenished as it had been—subsided so far that the width of the fertile interval between it and the town has increased to a league. Ancient shoals, now uncovered, appeared as islands; the site of a fort which had in 1740 been an island, became a peninsula; and the inhabitants were at once threat¬ ened with a scarcity of both wood and water. In 1822 I visited the district; but Venezuela was no longer subject to Spain. The smiling valley of Aragua had been the arena of most bloody contests; war and death had desolated those happy scenes, and greatly thinned the population. Its wide spreading cultivation was neglected ; and forest trees, of rapid growth within the tropics, had in great measure resumed their dominion over that region which its inhabi¬ tants, after a century of constant and painful labour, had reclaimed. When clearing was no longer continued, and lands once cultivated had again become part of the forest, the streams reappeared, and, as before, found their way to the lake, which once more overflowed a part of the cultivated plain, submerged the islands, and threatened soon to sever the fort from the main land. In the island of Ascension a beautiful spring issued from the foot of a mountain which was originally wooded. After a while the forests were felled and the moun¬ tain was cleared; when the spring becoming gradually less copious, at length failed. The disappearance of the spring was attributed to the clearing. The mountain was again planted, and after a few years the spring reappeared, became gradually larger, and finally was as copious as ever. Boussingault (abridged), Edinburgh New Phil. Journal , xxiv. (1838) pp. 89-91, 102-3. The ancient mining laws of Brazil strictly enjoin the careful preservation of forests at the sources of streams. “ Os roQeiros nao possao rossar de novo nas cabeceiras dos corregos de pouca “ agoa de que se uza para servitjos mineraes, e devao conservar o mato em dis- “ tancia de quinhentos palmas para evitar o damno da falta de agoa que por esta (< causa se experimental’ Regimento dos Superintendentes , Guardas-Mores, e Officiaes deputados para os Minas do Ouro. Bando , ou Additamento ao Regimento Mineral , 13 de Maio, 1736. Eschwege, Pluto Brasiliensis (Berlin, 1833), p. 145. The Meuse has varied in volume much more frequently, and has fallen far lower, since the forests near its sources have been destroyed, than formerly.” Professor Borgxet (M. Pimpurniaux), Guide du Voyageur en Ardenne, p. 164. District of Chaharcillo in Chili 139 of Copiapo; where, more than two centuries ago, a pleasant river flowed to the ocean through corn fields surpassingly fertile, and orchards rich in the fruits of every clime.* Of its condition during a long period subsequently we have no record ; but about forty years since great part of the same tract presented a surface of shingle, pebbles, gravel, and sand, covered with shells near the coast, and everywhere, more or less incrusted with salts of soda and magnesia; through which, for more than thirty miles, a scanty rivulet, thinly fringed with dwarf willows, wound its way to the sea.f Further up the valley, however, trees still * “ The valley of Copiapo is the first of the inhabited valleys of Chile. * * * “ The land is of itself very fruitful, and is made more so by a pleasant river, “ which runs about twenty leagues in it before it empties itself into the sea, in “ a bay which makes its harbour. Here grow all sorts of the natural fruits and “ grains of the country and of Europe; the maize yields above three hundred “ for one, and the ears of it are almost half a yard long.” Historical relation of the Kingdom of Chile ; by Alonso de Ovalle of the Company of Jesus, a native of St. Jagoof Chile (Rome, 1649), Pinkerton, Voyages and Travels , xiv. p. 168. f “ On the 23rd of November, 1821, we set off from the coast for Copiapo. “ * * * The first part of the road lay along a level hard surface chiefly of rock, “ at some places covered with a thin soil. We then entered a broad valley, the “ sides of which were formed entirely of •water-worn stones and gravel, covered “ by a stratum or crust, several yards thick, of a rock composed entirely of “ broken shells, stretching, as far as we could discover, over the whole country “ bordering on the sea. The valley was three or four miles across, and bore “ every appearance of having been, at some former period, the channel of a “ mighty river, though now shrunk into a scanty rivulet, flowing almost unseen “ amongst dwarf willows, stunted shrubs, and long rank grass. The soil was “ completely covered, at every part of the valley, by a layer of salt, several inches “ thick, which has since been ascertained by analysis to be sulphate of soda, or “ Glauber’s salts. It lay like snow on the ground * * * ; the dust thrown up “ by the horses’ feet almost choked us, and the day being dreadfully hot, made “ our thirst excessive, when we hailed with delight the sight of a stream ; but, “ alas ! the water was as salt as brine.”— Hall, Journal written on the Coasts of Chili , Peru, and Mexico , in the years lS20,-21,-and 22, ii. p. 21. “ There is very little land cultivated down the valley ” of Copiapo; “ its wide “ expanse supports a wretched wiry grass, which even the donkeys can hardly 140 W. J. Hen wood, on the Mining flourished round the homestead at Ramadilla. Between that time and the present, the proprietor,—tempted by the high price of fire-wood at Copiapo,—has felled every tree and grubbed up and sold every root on his estate. In May and June, 1857, the river, on entering Ramadilla, afforded rather less than twelve hundred cubic feet of water per minute; but,—thus exposed in a country where a week of occasional showers consti¬ tutes an unusually wet season,—it was wholly absorbed by the thirsty soil after a further course of only five or six miles. Even when swollen in summer by streams «/ from melted snow on the Cordillera, it never reaches the sea; but,—oozing through its deep beds of sand and shingle,—forms pools in the deeper parts of its ancient channel.* * The water j*—nowhere sufficiently pure for use on the Copiapo and Caldera railway—holds the sulphate of soda largely, and the sulphate of magnesia and common salt more sparingly, in solution. Large estab¬ lishments are therefore requisite for distilling river- “ eat. This poorness of the vegetation is owing to the quantity of saline matter “ with which the soil is impregnated. Layers of sulphate and carbonate of soda, “ even several inches thick, occur in some parts. * * * At present the river con- “ tains water enough to reach the sea.”— Darwin, Geology and Natural History of the countries visited by H.M.S. Beagle (1st Edit.), p. 442 :—(2nd Edit.) p. 362. * “ The Rio de Copiapo, which waters the valley, does not reach the sea, but is “ lost in salt pools above twenty miles from the port, and the whole country around “ is covered with a thick incrustation of salt; at some distance from it vegetation “ disappears. Between this place and the sea the country is a complete desert. “ At the village of Ramadilla the water becomes drinkable, and the whole aspect “ of the valley is changed, it being covered with a vigorous vegetation, as far as “ the water reaches. The width of the valley is from one to two miles, and that of “ the river varies from twenty to thirty feet.” Dr. Maven, Journal of the Geographical Society , yi. (1836) p. 369. f Analysed by J. Barclay Montgomery, Esq., M.D. District of Chaharcillo in Chili . 141 water at Piedra Colgada, and sea-water at Caldera,* for service in the locomotive boilers. Since the trees have been destroyed and the stream has been more rapidly dissipated and absorbed than before, several reedy swamps, between the Ramadilla house and Piedra Colgada,—formerly frequented by flights of beautiful wild-fowl,—have disappeared; and many of the more distant fields have been abandoned to the desert. Near Monte Amargo, a tract of several square miles is covered with a saline crust at least an inch in thickness. As each successive irrigation from the river deposits its salts, the ground so watered becomes gradually less productive; it is therefore periodically flooded and puddled, when the noxious ingredients pass off in solution. Land thus cleansed bears tolerable crops of wheat, barley, pumpkins, and cabbages, whilst the melilot (melilotus )—called by the natives alfalfa, and by the English lucerne—flourishes with extraordinary luxuriance. But unwashed ground, before it is entirely incrusted with salt, yields only a dry, hard, prickly, and bitter grass, on which mules, asses, sheep, and young cattle browse,')' and the Guanaco—stealing down * Although small quantities of brackish water are drawn from wells near the beach, the inhabitants of Caldera obtain their chief supply for domestic purposes from sea-water distilled by the Copiapo and Caldera Railway Company, who realized from its sale j in 1854 . £1003 8 5 5 . 1355 9 1 6 . 1359 6 11. Cartas de los Directores a los Accionistas de la Compania de la Ferro-Carril de Copiapd, 1855-6. t An attempt to naturalize the llama was made at Ramadilla; but,— like earlier trials near the coast,—it was unsuccessful. 142 W. J. Henwood, on the Mining from its home amid the sands and crags of the desert— feeds at night.* Whilst the lower part of the valley was undergoing these transformations, the upper seems to have suffered little or no change. Like the Copiopo valley below Ramadilla, every glen and ravine in Chanarcillo exhibits enormous beds of shingle, pebbles, gravel, and sand, deeply scored, as if by running water;')' but shorn of the coppice with which it was formerly clad, it now neither affords a trace of verdure nor contains a single well. As the district is thus destitute of means for working either water or even steam machinery, horse-whims (pique tornos) are the only means available for raising ore to the surface; but these are inadequate to the greatest depths. J * Whilst visiting its feeding-grounds the guanaco sometimes falls a prey to the miners, and forms a welcome addition to their meager fare. When taken young it is easily domesticated. t Ante, p. 70. J “ The ore and the deads which were formerly drawn out of the mine by the “ labour of horses, are now brought to the surface by the application of the “steam-engine. The difference of the expense of steam and horses for this “ purpose is nearly fifty per cent. From the increased number and the increased “ depth of the mines, this work could not possibly be performed at present by “ horses.”— Carne, Cornwall Geol. Trans., hi. p. 61. “ Since steam has replaced horse-power, winding machinery has accomplished “ the same work, at less than one-tenth of its previous expense.” Captain Nicholas Vivian, Manager of Wheal Towan and Condurrow, MSS. (1830). At the Cam Brea Mines , there were consumed in five winding-engines, during the first nine months of 1860,— District of Chanarcillo in Chili . 143 In mines where lodes are systematically wrought, Coal...... tons cwt. qrs. lbs. 722 1 0 0 .. which cost .. £595 13 9 Tallow.... 0 9 0 4 .. >» • • 27 12 10 Hemp .... 0 4 2 21 .. » • • 10 18 9 Candles . •. . 348 lbs. .. » •* 9 8 6 Oil . . 412 g a ii° ns tt •• 8 18 8 or at the rate of..... .... r... £870 The materials used in different whim-shafts, during one entire year, were— tons cwt. qrs. lbs. Chain. 16 3 3 26, which cost £422 Iron plates for 3 4 per ann. buckets & skips Rope ... Sundries 2 2 0 0 0 0 0 , 0, 99 99 120 80 25 0 0 0 0 0 0 0 0- Estimated wear and tear of steam-engines, at £50 each., -647 250 0 0 0 0 Cost of machinery and materials... *.£1,767 3 4 per ann. The wages paid during the first nine months of 1860 were— to Engine-men...£203 5 0 Kibble-fillers ... 365 15 0 „ landers. 346 10 0 or at the rate of............ 1220 13 4 per ann. Total expense .£2,987 16 8 per ann. The ingredients drawn out of the mine were— tons Tin-stone, containing about 0*0175 its weight of tin-ore—‘about 36,000 per ann. Copper-ore, ,, 0*5 ,, fit for the market, 6,000 Rubbish from cross-cuts and unproductive parts of the lodes .... 6,000 n a Tons 48,000 per ann. The produce,—raised one-half from 100-130, the other from 160-200 fathoms deep,—was delivered on the surface, at a cost of about one shilling and three pence per ton.— Compiled from Account Books at the Mines. Henry CurWen Salmon, Esq., F.G.S., Mining Journal (1860, December 15th), xxx. p. 84 (abridged). At Junge hohe Birke, near Freiberg, the same force applied to ropes of differ¬ ent materials, in a nearly perpendicular shaft, afforded, on an average, the follow¬ ing daily results Weight raised > r » * " •*• 1 - — - - — i with hempen rope with iron-wire rope . 60 tons. 70 tons. .28 „ 36 ..22 „ 30 M. Combes, Traits de VExploitation des Mines , in. p. 225, Depth. fins. 46±. 107± . 190 . 99 99 Z 144 W. J. Hen wood, on the Mining all broken ore is conveyed, in wheelbarrows or by tram-ways,* through horizontal galleries to the shafts. “ At Wheal Friendship Mine in Devonshire there were two inclined planes, “ * * * both beginning near the same point on the surface." The one which was first constructed “ was about five hundred yards in length, and the perpen- “ dicular depth from the surface was six hundred feet, the angle formed with the “ horizon being about twenty degrees; but another plane is now in use, which u is six hundred and fifty yards in length, and attains to a perpendicular depth “ of about one thousand and twenty-five feet below its mouth, or eleven hundred “ below the surface. The inclination which it forms with the horizon varies from “ thirty to forty-five degrees. * * * A small track of edge-rails is carried along “ the plane from top to bottom; and the ore is drawn to the surface in a wrought- “ iron waggon, by the force of a large overshot water-wheel.” Encyclopedia Britannica , Mining, xv. (Eighth Edit. 1858), pp. 225-6. * “ Railways have lately been used in the levels of the Consolidated Mines , “ Poldice, Treskerby, Huel Damsel, and other mines, and it is estimated that the “ expense of work performed by means of rail-carts, compared with that of the “ same work done by wheelbarrows, is less than one half.” Carne, Cornwall Geol. Trans., hi. p. 65. In the mines of Blanzy, seven labourers,—of whom two fill whilst five wheel the barrows,—convey 6,400 kilogrammes of coal one kilometre in eight hours, at a cost of ten francs and a half; or at the rate of— 100 tons carried 100 fathoms for £1 : 4 : 6. Combes, Traiti de VExploitation des Mines, in. pp. 8, 9. The ordinary day’s work of each Trammer on an iron railway at Roche-la- Moliere is represented by 3,159 tonnes (3,159,000 kilogrammes) of coal carried one metre ; 5 hectolitres (400 kilogrammes) are transported 580 metres, at an ex¬ pense,—beside loading,—of 20*83 centimes ; a rate equivalent to the carriage of 100 tons 100 fathoms for about £0 : 19 : 0. Ibid, hi. pp. 12-14. Since tram-waggons have replaced wheelbarrows underground, the same work has been accomplished at about one-fifth of its previous expense. Captain Nicholas Vivian, MSS. (1830). The following columns show the cost of conveying one hundred tons one hundred fathoms,—as well by wheelbarrow as by tram-waggon,—in different parts of Cornwall and Devon. Mine. Wheelbarrow. Tram-waggon. Authority. Cornwall. Wheal Clifford . £17 0 0 .. £7 10 North Roskear .. 5 15 4 .. 1 3 Providence Mines . 5 0 0.. 1 7 South Wheal Crofty .. 4 12 4.. 1 8 Devon. Wheal Friendship .... • 8 6 8.. 2 12 Other Mines near Tavistock 7 10 0 .. 2 10 0— Capt. John Richards, MSS. 1—Capt. Joseph Vivian, „ 1—Samuel Higgs, Esq., „ 5—Capt. Wm. Rutter, „ q | Jos. Matthews, Esq. „ The same work is therefore accomplished by tram-waggons at (between one District of Chanarcillo, in Chili . 145 In Chanarcillo, on the contrary, the few horizontal portions of the works,— presenting still the ragged surfaces left by blasting,—occur at such different depths that they are quite unsuited, either to wheelbarrows or railways; nor, in fact, is one or other used underground in the district.* * Attempts to introduce the windlass were immediately forbidden by native mine-owners.f The system of shafts, galleries (levels), and winzes, by which lodes are now % laid open elsewhere (Pl, III. fifth and two-fifths) about one-third of the rate paid when wheelbarrows are used. At Wheal Clifford, —where the temperatures of different levels (galleries) range from 80° to 100°,—men are unwilling—many indeed are unable—to under¬ take, even for enormously high wages, the labour they readily and cheaply perform in other—shallower—mines, in which the heat averages less than 65°, and sel¬ dom reaches 70°. * “ The enormous expenses of transport would be perhaps diminished more “ than two-thirds, if the works communicated with one another by galleries “ adapted for conveyance by wheel-barrows and tram-roads. Well contrived “ operations would facilitate the extraction of minerals and the circulation of “ air ; and the men employed in carrying ore might be employed in a manner “ more advantageous to society, and less hurtful to the health of the individual.” Humboldt, Political Essay: on the Kingdom of New Spain, hi. p. 240. f Several winzes (Ante, p. 53, NoteJ) opened and fitted with windlasses and buckets, by the English Superintendent (Ante, p. 123, Notef), for raising ore from the deeper parts of Colorada and Desempeno (PI. II.), were dismantled, because the native proprietors preferred the ancient Chilian mode of conveyance; —in bags on the backs of their (apires) workmen. J Whilst the miner’s works were extended so far only as ore was visible, he extracted all within reach as quickly as possible ; and,—having no guide to discovery,—then abandoned his mine. But when it was ascertained that the earthy constituents of richer were essentially different from those in poorer parts of lodes, and that the rocks adjoining them presented also each its peculiar character; he—limited no longer to the capricious meanderings of their metallic ingredients alone—now pursued his search, amongst congenial earthy parts of the lodes with which the ores were associated, by means of horizontal galleries (levels); and thus, by a straighter, — and therefore a shorter and cheaper, —course attained his object more quickly, and opened, at the same time, passages suitable for either wheel-barrows or tram-roads. That the present systematic mode of opening mines originated in this manner 146 W. J. Henwood, on the Mining fig . 2, 3), is not yet appreciated in Chili, where they are explored by means of (Chijflones) pits sunk ob¬ liquely at angles seldom more than 60° or less than 40°, and averaging about 50° from the horizon. These, —extended, downward and alternately towards oppo¬ site points, for distances and at inclinations determined in each case by the richnesss, hardness, or other pecu¬ liarity of the lode ,— form irregular zig-zags; more easily to be understood from an inspection of (Pl. II.) the section than from any verbal description. As there are no ladders in the shafts, the chijflones are the only means of access to the works, as well as the only passages through which ore is conveyed to the shafts from distant recesses and depths beyond the reach of horse-power. The Chilian mine-owner declines every prospective advantage, purchased by the smallest present outlay, the floors therefore consist, for the most part, merely of ragged ledges fortuitously left when the passages were first opened; where the surface affords no foot-hold, a step is cut here and there; and, when the seems unquestionable. Traoes of it occur in works executed at (Dolcoath) Bullen Garden (Pryce, Minerabgia Cornubiensis, pp. 170—181. PI, IV.) as early as 1778, But when, where, or by whom the change was made,—if indeed it were entirely accomplished in any one mine,—there are now no means of ascertaining, “When Dolcoath, which had been closed in 1786, was reopened in 1800, I “ found that the great mass of copper-ore it formerly yielded had been wrought “ by bottom-stores (Pryce, Mineral. Cornub. p, 161). Beyond these the lode ,— “ explored to considerable distances in several levels and winzes ,—afforded ore “ in many places, which were generally worked by bach-stores (Came, Cornwall Geol. Trans., iji. p, 70).”— John Rule, Esq,, MSS. But notwithstanding the system of levels, winzes, and bach-stores prevailed in every other part of Cornwall, bottom-stores were wrought until 1816 in Wheal Alfred (Carne, Cornwall Geol. Trans,, hi. p. 69), and 1840 in Wheal Vor. District of Chanarcillo in Chili . 147 chiffiones are more than commonly steep, trees notched at the sides serve instead of ladders, Over such steps, worn by many weary feet,—lighted by a small lamp, hung in gymbals at one end of a stick that it may be brought near the floor,— the labourer (apire) carries nearly two hundred pounds weight of ore in a leathern bag on his shoulders aided sometimes by a rail along * “ The Indian tenateros who may be considered as the beasts of burden in the “ mines of Mexico, remain loaded with a weight of from 242 to 377 pounds for “ a space of six hours. In the galleries of Valenciana and Rayas , they are ex- “ posed to a temperature of from 71° to 77°; and during this time they ascend “ and descend several thousands of steps in pits of an inclination of 45°. These “ tenateros carry the minerals in bags ( costales ) made of thread; and to prevent “ their shoulders from being hurt (for the miners are generally naked to the “ middle), they place a woollen covering (frisada) under this bag. We meet in “ the mines with files of fifty or sixty of these porters, among whom there are “ men above sixty and boys of ten or twelve years of age. * * * Where the “ principal passages unite, two persons (despachadores) , provided with balances, “ keep a book containing the names of all the ( tenateros ) porters. Persons “ stationed near the scales judge the weight of each man’s load by lifting it. If “ the carrier believes his load lighter than the despachador he says nothing, “ because the error is in his favour; but, on the other hand, if he believes it “ heavier than it is estimated, he demands that it shall be weighed, and the “ weight thus determined is entered on the book of the despachador.”— Humboldt, Political Essay on the Kingdom of New Spain, in. pp. 238-9,248-9. “The surface of the strata in the mine, fortunately, was irregular; but so “ worn by the miners’ feet, when bearing their loads upward, and so much “ polished by their sliding down again, that we found it no easy task to avoid “ slipping at once from the top to the bottom.”— Hall, Journal written on the coasts of Chili , Peru, and Mexico, ii. p. 30. “ The apire takes his load part of the way by a steep passage, but the greater “ part up notched poles, placed in a zigzag line up the shaft. According to the “ general regulation, he is not allowed to halt for breath, except the mine is six “ hundred feet deep. The average load is considered rather more than 200 “ pounds, and I have been assured that one of 300 pounds by way of a trial has “ been brought up from the deepest mine. At this time the apires were bringing “ up the usual load twelve times in the day; that is, 2,400 pounds from eighty “ yards deep; and they were employed in the intervals in breaking and picking “ ore.”— Darwin, Journal of Researches into the Natural History and Geology of the Countries visited during the Voyage of H.M.S. Beagle round the World (2nd Edit.), p, 340. 148 W. J. Hen wood, on the Mining the precipitous edges of ancient works, or by a strip of hide fastened to a peg in the rock, when his path is steeper or less practicable than usual. The operations of crushing and cleaning (dressing) the ore, — elsewhere cheaply accomplished by ma¬ chinery, are, at great expense, performed in Chanarcillo by hand ; enormous quantities,—too poor to defray this additional cost,—are therefore either left unbroken in the mines or rejected when brought to the surface, which might have been wrought to advantage had the district been but ordinarily supplied with water.* * The numbers of Government concessions for mining purposes (Pertenencias), f of people employed on “ Sur la totalite du nombre des gens occupes dans le travail des mines, * * u plus de deux cinquiemes se compose de chargeurs ou apires, c’est a-dire “ d’hommes d’une force musculaire prodigieuse, dont le travail est fait dans les “ mines de l’ancien continent par des enfants, des animaux ou des machines.” Domeyko, Annales des Mines, 4me S6rie, ix. p. 460. * “ It is computed that at Chanarcillo there are more than 300,000 tons of ore “ piled in immense heaps, hitherto useless, and occupying the valuable ground in “ the vicinity of the mines. They are judged to have a lei, or per centage of “ pure silver of from 6 marcs, or 48 ounces, to 50 marcs, or 400 ounces, to the “ ton, and at present without any available means whatever of reducing them. “ * * * These have been picked over and rejected because not of the richest “ ore; but are left for more leisurely examination, when mule hire will have be- “ come more reasonable and provisions more plentiful.”— Colonel Lloyd, Report to the Foreign Office on the Mines of Copiapd (London, 1857), p. 14. In May, 1857, two experienced Directors of the largest mines in Chanarcillo carefully examined all ore lying rejected on the surface at Colorado, and Desem- peno ; when one-third of it was found to afford 51 (Troy) ounces (0*00156 its weight) of silver per (Avoirdupois) ton of ore; the other two-thirds,—consisting of earthy and stony matter only,—were worthless. f “ Por el articulo 2° titulo 8° de la Ordenanza de Mineria, se conceden atodo “ peticionario 200 varas meditas a nival por el hilo, direccion o rumbo de la “ veta.”— Memoria que el Intendentede la Provincia de Atacamapresenta al Sehor Ministro de Estado (Copiapo, 1853), p. 127. District of Chanarcillo in Chili 149 them, and their produce at different been,— Date. No of Pertenencias. 1842 . 83* ... 1851.115f ... 2 . — ... No. of persons employed. 745* . 1677f . 3—(first six months). 161t .... 291 It . periods, have Ore extracted. Tons .. 1008-00* .. 3962*75t .. 6386*381 .. 4015*28: * The following abstract of Government records affords a view of proceedings at Chanarcillo during the year. MINES PERSONS 1842 Produc- Unpro- Labour- Water- Ore extracted tive ductive Total Officers Miners ers Smiths carriers Total Tons J 3>H« • • 14 62 76 106 241 291 6 31 675 76- Feb... 12 64 76 106 257 323 6 36 728 82-2 Mar. . 11 70 81 110 266 316 6 41 739 68-1 April . 13 75 88 113 284 339 8 42 785 61-8 May. . 12 72 84 118 270 304 7 38 737 91*1 June . 13 68 81 121 271 324 6 37 759 92*05 July.. 15 69 84 126 277 306 10 40 759 85-95 Aug. . 12 82 94 131 273 321 6 41 773 84*2 Sept. . 14 77 91 134 273 332 6 38 783 8985 Oct.. 18 66 84 134 274 337 7 37 789 r 208*6 Nov... 14 67 81 129 256 316 9 38 735 \ ( 12 • • 39 70 97 2 11 219 Dec. j • • 64 M 79 158 183 6 27 453 j 168*15 1108* Domevko, Annales des Mines, 4me Serie, ix. p. 459. f Report to the Foreign Office on the Mines of Copiapo, p. 160. + Memoria que el Intendente de Atacama presenta al Senor Ministro de Estado , p. 121. 150 W. J. Henwood, on the Mining Many of these (Pertenencias) tracts adjoin the principal mines,* and are traversed by their lodes and branches; but from the cost of operations necessary to continued possession, and the inadequacy of their returns, numbers of them are abandoned within one year.f ( b .) From 1842 to 1853 the mining population continued to increase; but in 1857 it had already materially diminished. Throughout the rich, but barren, mining districts of Atacama officers and workmen would often want alike the common necessaries of life if they were dependent on such casual supplies only as hawkers would bring on the chance of finding individual customers. The proprietors of mines are therefore obliged to procure from a distance food and water for all their people. The monthly cost of rations averaged at Colorada (Table V.), during 1856, about one pound and twelve shillings per man. The rates of wages mentioned by M. Domeyko J in * Ante , pp. 123-4. f The mining privileges officially conceded and relinquished in the silver region of Copiopo only, numbered in two years,— 1851 . 1852 . Concessions. 312 . 767. Relinquishments . 173 .. 392. Memoria del lntendente de Atacama , p. 101. + “ Tout est tellement cher a Chanarcillo, que les frais d’exploitation y montent « a 70 et 75 piastres ” (14 ou 15 £) “ par mois, par chaque barretero (c’est- “ a-dire par chaque piqueur ou barretero , et le chargeur qui lui correspond, y “ comprisl’eau,lapoudre,la surveillance de la mine, etc.). II enresulte qu’ayant “ en 260 barreteros dans le mines de Chanarcillo en 1842, les frais generaux “ d’exploitation ont dft monter cette annee a 260 X 75 X 12 = 230,000 piastres “ par an. Enyajoutant: 1° le surplus de chargeurs ( apires ) dont le nombre “ excedait celui de barreteros de 56 et qui devaient coftter 12 X 56 x 22 = District of Chaharcillo in Chili . 151 1842, and Colonel Lloyd* in 1851-2, are neither reconcilable with one another, nor with those paid, workmen of the same classes, at Colorado, in 1856 (Table V.). The (afire) labourer,—generally of native Indian, but sometimes of African, extraction,—who accom¬ panies every (barretero) miner, aids in culling the ore and afterwards carries it to a shaft or the surface on his back. The Chilian miner,—using a hammer with one hand and his borer with the other,—himself f bores “ 14,784 piastres; 2° environ 20,000 piastres en frais extraordinaires, machines, “ etc. On obtient pour frais generaux d’exploitation 268,784 piastres.” Domeyko, Annales des Mines, 4me Serie, ix. p. 461. “ Salvadora Mine, belonging to Chileans; administered by a Cornish Captain. Per month. * “ Descubridora Mine. • Per month, 1 Administrador.......... £ 60 1 Accountant.. 20 36 Mayordomos and Watchers, 216 from £4 0 0 to £10 0 0 each 70 Miners, English, > £9 0 0 to £10 0 0 „ i • 290 Native, 2 8 0 to 3 8 0 » J 50 Peons . 3 0 0 99 150 60 Labourers. 2 6 8 99 140 3 Blacksmiths .... 10 0 0 99 30 2 Carpenters .... 10 0 0 99 20 7 Servants . 2 11 5 99 18 Labour alone, per month.... £944 Administrador ... 4 Mayordomos ... 71 Miners & Labourers, of whom 10 were English.. 225 12 0 Rations,materials, coal, general disbursements, and carriage ........ 109 16 0 Total, per month .. £385 16 0 Lloyd, Report to the Foreign Office on the Mines of Copiapo, pp. 18, 19. f Saint Just is now the only part of Cornwall in which, as in Chili, the hole for blasting is bored by a single workman. A A 152 W. J. Henwood, on the Mining the holes for blasting; but at times he is relieved by his assistant, who handles the boring-tools, whilst he gleans the ore. When the Cornishman is not engaged in directing other workmen, he is employed in sinking shafts or on some other special work requiring skill and expedition. Less independent, however, than the native miner, he needs the aid of a comrade * in boring his hole; each in turn,—as usual in Cornish mines,—guiding the borer and striking it with a heavy two-handed mallet . But though the Cornishman uses less gunpowder, his day’s work is nearly one-third greater than that of the native miner. (c.) The quantities of silver produced f and silver-ore exported J from the department of Copiapo, between 1830 and 1853, are shown in the following columns.:— * The Cornish miner—expert at the use of pick and gad (wedge),—widens the joints,—picks thin slices from between their smooth, hard sides,—and opens every softer seam of rock. Having thus destroyed the support afforded by natural structure, he so places his hole that its blast shall act at the greatest advantage on those parts which now offer least resistance; and if two holes be necessary, their explosions are so timed that the first shall make way for the second. The charge also is adjusted merely to rend, without displacing the rock; so that its pieces may be afterwards removed by aid of pick and sledge only. As the native miner is unskilled in using the pick, he requires more powder than the Cornishman to do the same work. f Memoria del Intendente de Atacama } p. 122. t Ibid, pp. 113, 114, 122. District of Chanarcillo in Chili 153 Silver-ore exported. Years. Silver produced. lbs. (Troy).* * * § Ore. Tons (Avoirdupois). Official estimate of Silver therein, lbs. (Troy). 1830 .... 4,104*6 1 3,696*6 2 .... 20,202* If 3 58,034-2 4 . • . * 51,027*3 5 52,209-8 6 .... 10,604-9 7 36,028*4 8 • •. • 9 39,213*0 63,961*6 1840 .... 1 2 .... 3 11,865*0 50,614*4 51,063*3 42,655*2 4 .... 75,814*3 5 94,586*0 6 .... 99,114*2 7 125,811*3 8 .... 160,946*8 9 210,958*6 1850 .... 238,561*6 1 218,034*6 2,725*86 113,646-4 2 .... 243,908*9 4,818*53 200,895-1 3 (4 months)| | 72,4080 2,032*84 84,753-5 lbs. 2,035,424-7 tons 9,577*23 lbs. 399,295*0 § j Total produce of Silver in twenty-j three years and four months ...) lbs. 2,434,7197. * Memoria del Intendente de Atacama, p. 122. f Silver was first found at Chanarcillo in 1831-2 (Ante, p. 69). J The account of exports relates to four months only; but the mining returns include half the year 1853. Memoria del Intendente de Atacama, pp. 121-2. § Between 1st Jan. 1851, and 30th June 1853, the department of Copiapo yield¬ ed 19,335-8 tons of silver-ore ; of which— Chanarcillo afforded 14,364*41 tons, or the 0 7429 part; Tres Puntas ft 3,814-25 „ JJ 0*1973 ft i San Antonio ft 513*66 „ ft 0*0266 ft y Romero ft 341*84 „ ft 0-0176 t> j Sacramento ft 301-64 „ ft 0-0156 ft • Total.... 19,335-8 tons. 1* Ibid, p 154 W. J. Hen wood. Notices of Notices of Copper-Mines near Copiapo, in Chili. The copper-deposits of Copiapo* * * § occur in felspathic, quartzose, and hornblendic rocks, which,—commonly lamellar but sometimes massive,—form high craggy Beyond these the hills on either rocks north and south are in great measure overspread with sand,J much of which is unconsolidated. In one spot at least,—el Bramador§ near Toledo,—loud noises may sometimes be heard when large quantities of it are drifting || before heavy gales. * Heaps of wood-ashes and copper-slag mark the sites of many ancient smelt¬ ing-works in the valley of Copiapo. When copper was first discovered at la Marquesa, —the most ancient mine in Yallenar,—is now unknown; but el Cdbre and Larraona, in the same depart¬ ment, were wrought during the year 1700 ; and other copper-mines were opened there soon after.— Memoria del Intendente de Atacama , p. 11. f Domeyko, Annales des Mines, 4me Serie, ix. pp. 366, 374. X Hall, Journal written on the Coasts of Chili , Peru , and Mexico, in the years 1820,-21 ,-and 22, n. p. 21 (Ante, p. 139, Note). Domeyko, Annales des Mines , 4me Serie, ix. p. 365. § “ I heard an account * * * of a hill in the neighbourhood * * * called “ ‘ El Brenador,’—the roarer or bellower; * * * as far as I understood it was “ covered by sand, and the noise was produced only when people, by ascending “ it put the sand in motion.” —Darwin, Geology and Natural History of the Countries visitedby II.M.S. Beagle (2nd Edit.), p, 361. At Reg Ruwan, in Cabool, “ hollow sounds, such as would be produced by a “ large drum, are heard when the sand is set in motion.” Burnes, Personal Narrative of a Journey to and Residence in Cabool f p. 157. Edin. New Phil. Journal, xxxm. p. 204. || “ At Nakous in Arabia Petraea * * * a bare mountain composed of hard “ sandstone * * * presents on two sides surfaces so inclined that the white “ and slightly adhering sand which covers it scarcely supports itself, and slides “ down with the smallest motion; or when the burning rays of the sun destroys “ its feeble cohesion. These sandy declivities are about 150 feet high. * * * “ I climbed with difficulty seventy or eighty feet, * * * and in climbing heard “ the sound beneath my feet, which made me think the sliding of the sand was Copper-Mines near Copiapd in Chili . 155 About three miles from Baranquilla, on the coast, a low but steep escarpment presents several nearly hori¬ zontal beds of recently formed sandstone; which— pierced here and there by dark hornblendic crags— extend several miles inland, as far as Copiapo valley below Monte Amargo. This sandstone is traversed by an infinite number of small irregular joints; and wherever these occur,—harder perhaps than elsewhere, —it rises slightly above the general level. At about three hundred feet above the sea some beds of this highly calcareous sandstone enclose near Quebrada Seca considerable quantities of broken and ill-preserved shells.* * Near Caldera, in a railway-cutting one hundred and eighty feet above high-water mark, large tracts of loose sand, several feet in depth, contain tolerably perfect shells in such enormous abundance, that they not only furnish lime,f to the whole neighbourhood, but are shipped to Coquimbo, Valparaiso, and other “ the cause and not the effect * * * I therefore slid down as fast as I could, and “ endeavoured with the help of my hands and feet to set the sand in motion. “ This produced an effect so great, and the sand in foiling under me made so “ loud a noise, that the earth seemed to tremble. * * * It appeared to me to “ have the greatest analogy to the humming-top ; but rose and fell like the sound “ of an Eolian harp.”— Seetzen (Monatliche Correspondenz, Oct. 1812, p. 393), Edinburgh Journal of Science, vn. (1827) pp. 51-3. The same phenomena are described by Mr. Gray.—Daubeny, Description of Active and Extinct Volcanoes, p. 437. Edinburgh Journal of Science, vi. p. 154. * In several extensive, level, and horizontal beds of shells, elevated from 60 to 230 feet above the sea near Valparaiso, the state of decomposition has an evident relation to the comparative height at which they are found.— Darwin, Proceedings of the Geological Society (Abridged), n. (1837) p. 447. f “ At Quintero near Valparaiso the sand contains beds of shells in a semi- “ fossil state, which are burnt by the natives for lime.” Cuming, Geol. Trans., 2nd Series, v. p. 265. 156 W. J. Hen wood. Notices of ports, with a like object. The same beds, in some parts so full of shells, are in others made up almost wholly of gravel, pebbles, shingle, and fragments of rock which have been bored by marine animals. Specimens from each of these deposits * were obligingly examined by Robert Etheridge, Esq., F.R.S.E.; F.G.S.; of the Ordnance Geological Survey, who observes;— “ The shells from Quebrada Seca are so rounded and worn that it “ is almost impossible to determine their generic much less their “ specific characters. Those from Caldera appear to be more modern u and are better preserved. I find amongst them the following ;— Quebrada Seca. Caldera. (300 feet above the sea) (180 feet above the sea) Panopea. Donocilla donacinum . Venus . Venus. Crassatella. Turbinella. Isocardia. Oliva Peruviana . Balanus. Turritella. Purpura . Pecten. Mactra Byronensis . Balanus . An argillaceous rock, bored by Pholas or Lithodomus. 11 They are of species which appear to be now living in the Chilian 11 and Peruvian provinces,—are entirely marine,—and undoubtedly u come from raised-beaches along the coast.” The beds of shells and their equivalents, perhaps, mark, and their depth may be in proportion to, the intervals of repose; the sand,— almost destitute of * All these have been placed in the Museum of Practical Geology (Jerinyn Street, London). Copper-Mines near Copiapd in Chili. 157 shells,—was, on the other hand, probably deposited during periods of elevation. The frequency of earthquakes, and the terrific effects they have often produced, on the coast of Chili are generally known. # * De TJlloa, Voyage to South America, n. p. 257. Mrs. (Graham) Callcott, Geological Transactions, 2nd Series, I. p. 413. Letter to the President ancl Mem¬ bers of the Geological Society (London, 1834), pp. 1-9. Hall, Journal xoritten on the Coasts of Chili, Peru, and Mexico , n. p. 25. Scrope, Considerations on Volcanos , pp. 190, 208. Caldcleugh, Philosophical Transactions, cxxvi. (1836) p. 21. Proceedings of the Geological Society, n. (1837) p. 444. Lyell, Principles of Geology , I. p. 401. Bakewell, Introduction to Geology (4th Edit.), p. 98. De la Beche, Geological Manual (3rd Edit.), p. 143. Greenough, Proceedings of the Geological Society, n. (Presidential Address, 1834) p. 56. Alison, Ibid, n. (1835) p. 209. Darwin, Ibid, n. (1837) p. 447. Geol. Trans., 2nd Series, v. p. 601, Natural History of the Countries visited by H.M.S. Beagle (2nd Edit.), pp. 301-312, 351. Fitz-roy, Jour, of the Royal Geographical Society, vi. p. 319. Surveying Voyage of II.M.S. Adventure and Beagle, n. 402-418. At 8 a.m. on the 5th of October, 1839, an earthquake destroyed, in a few minutes, within the city of Copiapo alone, property valued at (£300,000) one million and a half of dollars; beside much more in the neighbourhood. Its effects were most disastrous along and near the valley which reaches from the Cordillera, through Pabellon, Copiapo, and Ramadilla, to the ocean; but— diminishing at greater distances on both sides of that line—they were felt, more or less severely, throughout Atacama. As far north as the confines of Bolivia,— ninety miles, at least, from the centre of disturbance,—shocks were perceived twelve or fifteen miles off the shore. At Coquimbo—about the same distance south,—on the contrary, they were scarcely noticed. During the first shock,—which lasted at least two minutes and a half—people with difficulty saved themselves from falling. Throughout that day and the night succeeding, shock followed shock with scarce an intermission; and for nearly a week there were fully one per hour. In about a fortnight they became much less frequent; but for four months three or four shocks were felt daily. A dull rumbling noise like thunder, or separate reports as of artillery at a distance, often accompanied the shocks; but there were also shocks without noises, and noises without shocks. It is not easy to describe one phenomenon observed at Caldera; whilst the convulsion was most severe; which may, how¬ ever be likened to a sudden concussion occasioned by the fall of an enormous weight from a great height. The first shock,—beyond comparison the most severe,—passing from north¬ east to south-west, destroyed or irreparably damaged, not only every tall chimney in the Mexican and South American Company’s, Messrs. Livingstone & Com¬ pany’s, and Messrs. Tagle & Company’s copper-smelting works,—but also every 158 W. J. Hen wood. Notices of During my brief stay in that country, seldom more than three days passed without a shock One only of them was however severe enough to dislodge portions of the ceiling in my room; and to show,—by the way in which it tilted my bed,—that its direction was from south-west to north-east. Another was noticed both at Copiapo and Chanarcillo,—places more than thirty miles apart,—whilst I was underground in Colorado; but it was not felt beneath the surface. The injuries occasioned by earthquakes, are, however, often severest in the shallowest parts of mines. That this coast has been more than once appreciably elevated, within the last forty years, seems unquestion- wall erected on the deep beds of sand and shingle, east of the harbour. But whilst buildings parallel to its course crumbled into irregular heaps, those at right-angles to it were simply laid flat, the bricks and moulded masses of copper- slag of which they were constructed retaining their relative positions unchanged. South of the harbour, contrariwise, the Copiopo Company’s stacks and smelting- houses,—founded on greenstone,—were uninjured. The native huts, of wood, were scarcely moved. The air was filled with clouds of dust, during a moment of unnatural stillness, after the first shock. At Caldera the sea gradually fell, from about quarter flood, beyond the ordinary level of low-water, leaving vessels aground and boats dry on the beach; then— slowly returning—it rose, some nine feet and a half perpendicular, to the usual high-water mark; and thus ebbed and flowed six times within an hour. The affrighted inhabitants escaped to higher grounds; and remained several days and nights in the dreary desert of Atacama. Along the great line of disturbance between Pabellon and Caldera several shallow copper-mines were destroyed and others -were much injured. At Flamenco and Chanaral on the coast northward many were greatly damaged. In the neighbouring districts of Tres Pantas and Chanarcillo, on the contrary, deeper works were but slightly affected. Near Caldera the coast seems to have been permanently raised; for rocks which were covered by the sea at high-water before the earthquake, are now at least a foot above the highest tide. Richard Johnstone, Esq., M.D.; and John Jos. Murray, Esq., H.M. Consul at Caldera; MSS. Copper-Mines near Copiapd in Chili. 159 able*; but whether the present positions of the several beds of shells f and other marine remains which *Mrs. (Graham) Callcott, Geol. Trans., 2nd Series, i. p. 413. Caldcleugh, Phil. Trans, cxxvi. (1836) p. 21. Fitzroy, Journal of the Royal Geographical Society, vi. p. 319. Surveying Voyages of H.M.S. Adventure and Beagle , ii. pp. 412, 414. Darwin, Geol. Trans., 2nd Series, v. p. 601. Natural History and Geology of the Countries visited by H.M.S. Beagle (2nd Edit.), pp. 301-312. Ante, p. 158, Note. f “Between Talcaguana and Conception, within four or five leagues from the “ shore * * * at a depth of half or three quarters of a yard beneath the surface “ of the ground, is a stratum of shells of different kinds, two or three toises in “ thickness, and in some places even more, without any intermixture of earth, “ large shells being joined together by smaller, and which also fill the cavities “ of the larger. From these shells all the lime used in building is made ; and “ large pits are dug in the earth for taking out those shells, and calcining them. “* * * Quarries of the same kind of shells are found * * * fifty toises, * * * “ and I saw them myself at the height of twenty toises above the surface of the “ sea. * * * The various sorts of shells which compose these strata both in “the plains and mountains, are the very same with those found in the bay and “ neighbouring places, * * * at the bottom of the sea in four, sixteen, and twelve “ fathom water.”— De Ulloa, Voyage to South America, pp. 252-4. “ Several ancient lines of beach, consisting of shingle mixed with shells, “ extend in a parallel direction to the shore, to the height of fifty feet above the “ sea.”— Mrs. (Graham) Callcott, Geol. Trans., 2nd Series, i. p. 415. “At the mouth of the Rapel sixty miles south of Valparaiso, dead barnacles “occur adhering to the rocks three or four feet above the highest tidal level; “ and in the neighbouring country marine shells are scattered abundantly to the “ height of about one hundred feet. Ten miles to the north, and at an equal “ distance from the sea, is the village of Bucalemu, in the neighbourhood of “ which are very extensive beds of recent shells. At the bottom of the great “valley of Maypo, and some miles from the coast, marine shells of existing “ species are also numerous; and at San Antonio near the northern point of “that river, are large quarries of shells. * * * Shells of various kinds, but all “ similar and in similar proportional numbers to those on the beach, form numer- “ ous beds, elevated from sixty to two hundred and thirty feet above the sea, along “ the bold granitic coast south of Valparaiso. * * * Near Vina del Mar, Balani “were discovered adhering to the stone about fourteen feet above high water; “ and in the same neighbourhood there is an abundance of elevated shells.” Darwin, Proceedings of the Geological Society (Abridged), n. (1837) pp. 446-7. “ Near Coquimbo five narrow, gently sloping, fringe-like terraces rise one “behind the other; which, where best developed, are formed of shingle. * * * “ At Guasco, north of Coquimbo, the phenomenon is displayed on a much grander “ scale. * * * The terraces are there much broader, and may be called plains ; “in some parts there are six of them, but generally only five; they run up the “valley for thirty-seven miles from the coast. * * * Shells of many existing 160 W. J. Henwood. Notices °f overlie many of the copper deposits* * * * § are the results of repeated displacements by earthquakes ; or may rather be due to a constantly progressive action,')' like that by which Scandinavia still rises,J is beyond the scope of this enquiry. Beneath a low steep cliff of shelly calcareous sand¬ stone,§ about three miles from the sea and three hundred “ species not only lie on the surface of the terraces at Coquimbo (to a height of “ 250 feet), hut are imbedded in a friable calcareous rock, which in some places “ is as much as between twenty and thirty feet in thickness, but is of little “ extent. These modern beds rest on an ancient tertiary formation containing “ shells, apparently all extinct. * * * I found no regular strata containing “ sea-shells of recent species, excepting at this place, and at a few points north- “ ward on the road to Guasco.— Darwin, Natural History and Geology of the Countries visited by H.M.S. Beagle (2nd Edit.), p. 343 (Abridged). Hall, Journal written on the Coasts of Chili, Peru, and Mexico, II. p. 6. * “ At Quintero * * great beds of shells, which stand some yards above the “ level of the sea, are burnt for lime. The proofs of the elevation of this whole “ line of coast are unequivocal; at the height of a few hundred feet old-looking “shells are numerous, and I found some at 1300 feet. These shells either lie “ loose on the surface, or are imbedded in a reddish-black vegetable mould. I “ was much surprised to find under the microscope that this vegetable mould is “ really marine mud, full of minute particles of organic bodies.” Darwin, Natural History arid Geology of the Countries visited by H.M.S. Beagle (2nd Edit.), p. 254. “Near Caldera in Chili an ancient beach now a mile inland and one hundred “ and eighty feet above the sea, affords the same Diatoms as the present strand. “* * * j n Sirocco-dust which fell at Malta Mr. Ralfs found several Chilian “ forms.”—J. Barclay Montgomery, Esq., M.D., Annual Reports of the Royal Cornwall Polytechnic Society , Part xxv. (1857), pp. 45, 47. f Darwin, Proceedings of the Geological Society, n. (1837) p. 448. Natural History and Geology of the Countries visited by H.M.S. Beagle (2nd Edit.), pp. 310, 344. X Von Buch, Travels through Norway and Lapland, pp, 217, 386. Lyell, Principles of Geology, n. p. 307. Reports of the British Association, in. (1834) p. 652. Phil. Trans., cxxv. (1835) p. 1. Keilhau, Edin. New Phil. Journal, xx. p. 425. Elie de Beaumont, Ibid, xxv. p. 301. Forchhammer, Geol. Trans., 2nd Series, vi. p. 157. Quarterly Journal of the Geological Society, i. pp. 376, 379. Eugene Robert, Edin. New Phil. Journal, xxvin. p. 386. Bohtlingk, Ibid, xxxii. p. 105. Nilsson, Quarterly Journal of the Geological Society, vn. Part ii. p. 112.—Domeyko, Annales des Mines, 4me S6rie, xiv. pp. 153-162. § Domeyko, Annales des Mines, 4me Serie, ix. p. 366. Ante, pp. 155-6, Copper-Mines near Copiapd in Chili. 161 feet above its present level, the mine of QUEBRADA SEC A. is wrought in thickly foliated rocks; which, southward, are very hard when—sparingly mixed at intervals with small garnets—quartz and hornblende are their chief ingredients; but are much softer, towards the north, where felspar prevails.* Calcareous spar, plentiful throughout the district, is especially so towards Cerillas, an adjoining mine, on the north. Structural planes, common to the whole formation however varied its composition, approximately coincide, both in strike and in dip, with the nearest metalliferous masses. But all these are not strictly parallel; f for the Vetas and the Guia (Fig. 10, a , h ) bear 35° N. of E. and S. of W., whilst the Manto (c) takes a nearly meridional direction; their general dip however is 30°-55° west. Fig. 10. (Transverse Section.) a. Veta. b. Guia. c. Manto. * “ C’est dans les masses granitiques associees aux roches porphyritiques et “ feldspathiques compactes, qu’on est encore en train d’exploiter les mines * * * “ de la Quebrada Seca et beaucoup d’autres du cot6 du Sud.” Domeyk.0, Annales des Mines , 4me Serie, ix. p. 367. t Ante, p. 22. 162 W. J. Henwood. Notices of Within a breadth of four fathoms on the west, three (vetas) veins (a)—each from two to ten inches wide, composed in great measure of quartz, but containing also earthy brown iron-ore, the green carbonate of copper, copper pyrites, and vitreous copper-ore,—have been opened and abandoned. East of these, the Guia ( b ),—sometimes as much as three feet, but averaging about a foot in width,—also consists for the most part of quartz mixed with horn- blendic, calcareous, and felspathic matter; and,—in its shallower parts, with earthy brown iron-ore. Small lumps of native copper incrusted with red oxide of copper, and coated with earthy black copper-ore, are sometimes mixed with massive green carbonate of cop¬ per, in a matrix of (gossan) siliceous brown iron-ore, near the surface; but the principal produce,—of black* and green chrysocolla, Atacamite, j' purple and vitreous copper-ore, and copper pyrites—occurs in quartz and felspar at greater depths. Still further east, the Manto (c),—generally about nine, but enlarging at intervals to thirty feet in breadth, —also contains great quantities of quartz, mixed, how¬ ever, with earthy brown iron-ore and ingredients common to the adjoining rocks far more abundantly than in the Guia. Native copper is invested by the * Domeyko, Annales des Mines, 4me Serie, xviii. p. 123. f “ Atacamite is often produced when metallic copper or copper-ores have been “ exposed to the action of the atmosphere, or of sea-water.” Mohs, Mineralogy (translated by M. Haidinger), hi. p. 75. Domeyko, Annales des Mines, 3me Serie, xviii. p. 123. Copper-Mines near Copiapd in Chili . 163 oxide and green carbonate of copper, in a matrix of earthy brown iron-ore, granular quartz, and felspar clay near the surface; whilst the silicate, chloride, and sulphurets of copper are disseminated through fel- spathic, quartzose, and hornblendic matter below. On either side, but especially east, of the Guia (6) and Manto (c), several large lode-Wke masses of vein¬ stone extend through the rock obliquely to its foliation. They do not however reach from one to the other, or mutually intersect; but become gradually less and less metalliferous,— slowly assimilate to the Country in mineral character,—and ultimately disappear. Smaller metalliferous branches, without number,—springing from the larger off-shoots as well as from the Guia and Manto ,—every where traverse the intermediate rock. Northward, where lime becomes a large ingredient in the rock, the Guia , the Manto , and their branches , —alike destitute of metalliferous quartz,—are repre¬ sented by thin and irregular plates of calcareous spar; merely tinged with the green carbonate of copper. All works less than fifteen fathoms deep are open to the day; whilst to an equal depth beneath the whole formation is irregularly honeycombed in all directions by the miners. The deepest pits contain a little water much con¬ taminated with the sulphate of soda and other salts; but the surface is destitute of both vegetation and moisture. 164 W. J. Henwood. Notices of Surrounded by high hills of sand drifted from the desert, though only twenty miles west-north-west of Copiapo,—the copper-mine of SAN JOSE has been sunk in a fine-grained massive crystalline rock, composed chiefly of hornblende and quartz; with which the carbonate of lime is, in some places, largely mixed. Fig, 11. Plan. Scale 40 fathoms to an inch. Two systems of veins, coinciding in direction with as many series of joints,—bear respectively 25°—30° S. of E. & N. of W.; and 30°—35° W. of N. & E. of S. Owing to this coincidence # their sides (walls) are generally smooth. Whatever their directions, they all dip 65°-78° south¬ west; whilst the shoots of ore incline towards the north-west. Their numerous intersections are unattended by dis¬ placement (heave); at and on either side of the contact, however, they often enlarge. But rich and regular as * Dr. Boase, Cornwall Geol. Trans., iv. p. 448; Primary Geology , p, 179. Fox, Report of the Royal Cornwall Polytechnic Society (1836), p. 89. De la Beche, Report on Cornwall , Devon , and West Somerset , p. 339. Henwood, Cornwall Geol. Trans., v. pp. 179-112, 259-262. Copper-Mines near Copiapd in Chili. 165 some portions are, no vein in San Josh has been traced as much as one hundred fathoms in any direction. A few rich veins are no more than three or four inches wide; but generally they are from two to three feet. A portion of the northernmost vein was indeed opened for a breadth of from fifteen to eighteen feet; in this place, however, it consisted of two principal branches enclosing a mass (horse) of rock, which minor strings of pure ore traversed in all directions. Their ingredients—partaking, as usual, the charac¬ ters of the adjoining rocks—are chiefly quartzose and hornblendic; but carbonate of lime, often black, is also abundant. Near the surface earthy brown iron-ore—■ sometimes yellowish # but mostly brown—is largely mixed with granular quartz, and, less plentifully, with calcareous spar; whilst the sides of numerous small drusy cavities are studded with mamillated and botry- oidal masses of malachite. At greater depths lumps and irregular veins of jaspery iron-ore, bluish-green and black chrysocolla, Atacamite, malachite, and vitreous copper-ore are interspersed through the other ingredients.')' Although the veins are wrought to a depth of thirty fathoms without trace of moisture; at less than ten fathoms north-east of them a shaft sunk but five fathoms from the surface, affords copious streams of pure water. * Ante, Table I., Purturburd.; Table II., Tilponl. t Near Tierra Amarilla copper pyrites occurs in a matrix of specular iron-ore. 166 W. J. Hen wood. Notices of Enormous quantities of copper in bars, regulus, and ore are exported from the northern parts of Chili. # X ' In the shallower parts of Quebrada Seca, San Josh, and other copper-mines of the neighbourhood, * The mining privileges officially conceded and relinquished in the copper districts of Copiapo, in two years, numbered 1851. 1852. Concessions. 89 . 407; Relinquishments. 61 . 123; and one hundred and sixteen copper-mines were wrought by nearly fourteen hundred workmen.— Memoria del Intendente de Atacama , pp. 101-2. “ On a extrait de ces mines, dans les dix annees, dupuis 1832 a 1842, 2,000,707 “ livres de cuivre en barres, et 70,000,000 livres de minerai de cuivre cru qu’on “ exporta en Angleterre, et dont le loi moyen a ete d’environ 23 a 25 p. 010.” Domeyko, Annales des Mines , 4me Serie, ix. p. 370. The quantities exported, were — in 1850, Ports. Copper in bars. Tons. Copper-regulus. Tons. Copper-ore. Tons. Coquimbo . Huasco . Caldera . TotCll/ • • • • 4739-54 548-74 17*15 1676-67 298-65 886-71® 1531-95® 1168-72« 5305-43 1975-32 3587-38 Coquimbo . Huasco and Caldera .. Total .... in 185f 2923-06 469-84 2632-54 2645-86 7644-57 & 5367-86C 3392-90 5278-40 13012-43 From all these ports .. and in 1857, 2167* | 17910- 21385-d “ besides large quantities to France, the United States, and Hamburgh.” a M. Cazotte, French Consul General in Chili; Annales des Mines, 4me Serie, xx. pp. 84-7. b > i ** Ibid, 5me Serie, iv. p. 520. c Memoria del Intendente de Atacama, p. 114. d Universal Review, iv. (No. xv. May 1860) p. 648. The copper-ores purchased at various establishments of the Mexican and South American Company in Chili, during i ^ contained.. 1849 S . 1850 .. 1851 i, . >1 1852 .... 99 1853 1. 99 and averaged for the whole period. 99 99 Alison, Letter to the Mexican 8$ South American Co. (London, 1856), p. 46. Copper-mines near Copiapd , in Chili. 167 gold* * is sometimes mixed with ferruginous quartz; but rarely in quantities sufficient to make it an object of special pursuit. Regulus manufactured by the same Company, in 1855 contained . from 62 , 4 to 71'0 of copper. 1856 „ . „ 58-0 „ 67'8 „ Alison, Letter to the Mexican % South American Co. (London, 1856), pp. 75-6. The dry method of assay only is practised in Cornwall;—the wet alone in Chili. “ The Chilian miners have the reputation of being great cheats ; and the most “ serious frauds are committed in the sale of copper and silver ores by bribing “ the samplers; and, the mode of sampling being imperfect, the frauds are not “ detected if the ores get into the native furnaces, or until the exported ores “ arrive at Swansea.”— Universal Revieio , iv. (No xv., May, 1860) p. 649. * “ On compte trois epoques dans l’histoire de l’industrie minerale de Copiapo. “ D’abord, du temps des premiers conqudrants et sous le regime colonial espagnol, “ on n’y travaillait que des mines d’or. 11 parait qu’on avait trouve des quan- “ tit^s immenses de ce m£tal aux affleurements des filons. Secondement, vers la u fin du dernier siecle, l’epuisement des principaux filons auriferes, ou plutot “ l’appauvrissement des minerals dans la profondeur (fait gen^ralement observd u dans toutes les mines d’or du Chili); ensuite, la decouverte des mines de “ cuivre (dont les filons se trouvent dans les memes localitds que les filons d’or); “ celle enfin des quelques mines d’argent, firent abandonner les mines d’or, et on “ commenvja a s’appliquer a l’extraction du cuivre et de l’argent. * * * Les “ minerals d’or donnaient, terme moyen,” (0*00003125) “pour 58 piastres d’or “ par caisson (ce qui que revient a peu pres a 20 castillanos, c’est-a-dire a 2 “ dixiemes de livre d’or par 64 quintaux). Quant aux minerals de cuivre, on “ n’extrayait que des minerals oxyd^s ou autres contenant au moins 30 p. 0|0 “ de cuivre.”— Domeyko, Annales des Mines , 4me Serie, ix. pp. 368-9. “ At Coquimbo gold is found in a matrix of carbonate of copper.” Caldcletjgh, Travels in South America, i. p. 351. 168 W. J. Hen wood, on the Gold-Mines On the Gold-Mines of Minas Geraes, in Brazil. The richest gold-field in Brazil,-—between Congonhas do Campo* on the south, Candonga on the north, the Rio das Velhas and other tributaries of the Rio Sao Francisco on the west, and several branches of the Rio Doce on the east,—is about one hundred miles in length, and from fifty to seventy in width. Beyond the confines of this region also many mines have been opened; and some of them are still productive. That part of the district which consists of ( Campos f ) undulating table-land and low rounded hills,—between two and three thousand feet J above the sea—is covered with (Capim § gordura. Trigestis glutinosa , Nees; Agrostis glutinosa , Fisch; Suardia pieta, Schrank ; || * “ Man pflegt daher an dieser Grenze sehr viele Orte mit dem Beinamen : Xi do Mato dentro oder do Campo zu unterscheiden.” von Spix und von Martius, Reise in Brasilien, II. p. 423. f Maive, Travels in the interior of Brazil, p. 225. von Spix und von Martius, Reise in Brasilien , i. p. 395. Auguste de Saint Hilaire, Voyage dans les Provinces de Rio de Janeiro et de Minas Geraes, I. pp. Ill, 195. Caldcleugh, Travels in South America, n. p. 218. Gardner, Travels in the interior of Brazil, pp. 479 491, 495. J von Spix und von Martius, Reise in Brasilien, tii. Geographischer Anhang, pp. 39, 40. \ “ A Rio de Janeiro, cette plante porte le nom de Campim melado. Le mot “ guarani capim, ou, pour etre plus exact, capyi (Thes . de la leng. guar.), signifie “ herb, foin. Cette expression s’est introduite parmi les Bresiliens, quoiqu’elle “ ne fut pas necessaire dans leur langue, puisque l’on a en portugais le mot feno. “ L’habitude de vivre parmi les Indiens a pu seule faire adopter aux Portugais “ le mot capyi.” — Saint Hilaire, Voyage dans les provinces de Rio de Janeiro et de Minas Geraes, I. p. 194. || Ibid, i. p. 194; n. pp. 291, 311. von Spix und von Martius, Reise en Brasilien, i. p. 401; n. p. 423. of Minas Gerdes, in Brazil . 169 Melinis minutiflora , Gardner.*) coarse grass and ir¬ regularly dotted with (Capoes'\) natural clumps of shrubs; the remainder — rising into isolated peaks and deeply serrated ridges five or six thousand feet high,J—is, in many places, still richly clothed with * “ The hills around the Cidade do Serro, are covered with a grass which the “ Brazilians call Capim gordura (Melinis minutiflora, Nees ab. E.). It is covered “ with an oily viscous matter, and universally makes its appearance in those “ tracts, which have been cleared of virgin forest for the purposes of cultivation ; “ both cattle and horses are very fond of it, but although they soon fatten on it, “ the latter get short-winded, if they feed on it for any length of time. Martius “ considers this plant to be truly a native of Minas Geraes, while St. Hilaire is “ of a different opinion; as it is now everywhere so common in this province, it “ is a difficult matter to say which of those excellent botanists is in the right; “ all the agriculturalists that I have spoken with on the subject agree with St. “ Hilaire, although they differ in opinion in regard to the place of its original “ growth. * * * It is rapidly extending northwards * * * but is not to be met “ with at all in the Sertao.”— Gardner, Travels in the interior of Brazil , p. 477. f “ Der Abhang ist mit Grascampos und einzelnen Gebiischen bedeckt, und “ hie und danimmt eine dichte Waldung von niedrigen, stark belaubten Biiumen “ die Binnsale und die Vertiefungen ein. Diese Waldschen, welche man hier “ zu Lande (von dem verdorbenen Worte der Lingua geral Caapoao, Insel) “ Capoes , gleichsam Waldinseln, nennt, bilden einen eigenen Zug in der Land- “ schaft der Camposgegend, und bestehen grdsstentheils aus Pflanzenarten, “ welche nur in ihnen vorkommen. * * * Hieher gehoren mehrere Arten der “ Gattungen Laurus, Vochisia, Annona, Uvaria, Xylopia, Myrtus, Inga, Wein- “ mannia, Styrax, Bauhinia, Coccoloba, Chiococca, Amajovea, Chomelia, Sapium, “ Gymnanthes, Spixia, von Ranken der Paullinien und Echites durchschlungen.” yon Spix und von Martius, Reise in Brasilien , i. p. 395. “ Les bouquets de bois dans les Campos qui les habitans appellent capoes . “ * * * L’etymologie du mot capao est assez jolie. II vient de caapohm, qui, “ dans la lingoa geral, signifie ile.”— Saint Hilaire, Voyage dans les Provinces de Riode Janeiro et de Minas Geraes , i. p. 113; n. p. 98. “ The undulating open barren country affords only here and there a few clus- “ ters of trees in hollow places ; to these isolated woods the name of Capoes is “ given, an appellation which is highly poetical, being derived from the Indian “ word Caapoam, which signifies an island. These island-woods form a peculiar “ feature, in the upland, open, undulating Campos of the province of Minas “ Geraes. The trees which compose them, chiefly consist of different species of “ Myrcia, Eugenia , Vochysia , Anona, Lauries, Styrax , &c., intermingled with “ climbing shrubs, such as Bauhinia, Paullinia, &c.” Gardner, Travels in the interior of Brazil, p. 431. J The Serra de Piedade is 5400 (English) feet above the sea; Itacolumi........ 5710 Itambe. 5965 yon Spix und yon Martius, Reise in Brasilien, i. p. 396; H. pp. 422, 456. 170 W. J. Henwood, on the Gold-Mines virgin forests; # which are protected by stringent laws.f The auriferous series consists of granite £ and * Saint Hilaire, Voyage dans les Provinces de Rio de Janeiro et de Minas Geraes, ii. p. 98. “ The Matos Virgens, or virgin forests, are such as those which exist on the “ Organ Mountains, and indeed along the whole maritime Cordillera. To these “ also belong the Capdes of the Campo countries. Next to the virgin forests “ come the Catingas , the trees of which are generally small and deciduous, and “ form the connecting link between the virgin forests and the Carrascos , which “ grow on more elevated tracts than the Catingas , and consist of close growing “ shrubs about three or four feet high. These are all natural woods, very different “ from * * f the Capoeiras , which are wooded tracts formed by the small trees “ and shrubs which spring up in lands that have been prepared for cultivation “ by destroying the virgin forests, which is generally effected by setting fire to “ them; the trees that then spring up are always very distinct from those which “ constituted their original vegetation.”— Gardner, Travels in Brazil , p. 432. t “ Entre as rossas vizinhas que hoje partem por matto virgem se conserve nas “ partilhas, ou extremos huma linda de duzentos palmos de cada parte a qual de “ novo senao podera rossar sent licen^a do Governo precedendo informa^oes “ authenticas se nellas ha arvores de lei que se devao conservar, pois a experi- “ encia mostra que a natureza das terras as nao produz de novo, ou tarda seculos “ para as produzir, e quem sent esta licentja rossar as ditas Lindas perdera todo “ o dominio e posse que nellas tiver, e ficara por esse mesmo feito aplicada ao “ vizinho com quem parte, que a podera semear, e desfructar sem que aquelle “ que a rossou possa pretender delle causa alguma, alem da pena de cincoenta “ oitavas pagas da cadea para o denunciante, e se ambos os vizinhos contravierem “ juntamente esta disposi^ao pagara cada hum a pena em dobro. ******* “ Em todas as rossas, terras, sitios, ou vertentes, que se concedessem, ou de “ alguma sorte se occupassem depois do dia 30 de Outobro de 1733, ou occupao “ em terras de matto virgem, serao obrigados a conservar a decima parte por “ rossar da mesma sorte debaixo das mesmas penas que atraz se declarou acerca “ das Lindas, ou extremos das demarcates.”— Regimento dos Superititendentes, Guar das-Mores , e Offciaes deputculos para as Minas do Ouro. Bando ou Addita- mento (to Regiminto Mineral , 13 de Maio de 1736. Southey, History of Brazil, m. pp. 825-6. J At Gongo Soco “ the Serra which runs from east to west, and lies to the “ north of the mine, is of primitive character, the mass of its centre consisting “of granite; upon the granite is imposed a thick bed of schistose and clay “ slates, cropping out at an angle of about 45°. Above this lies another thick “ bed of ferruginous Itacolumite, having the same inclination as the rocks below; “ and immediately over this the Jacotinga, or soft micaceous iron schist, which “ contains the gold, and which is about fifty fathoms in thickness. Above the “ Jacotinga is another thick layer of Itacolumite ; and lastly about half a mile of Minas Gerdes, in Brazil. 171 gneiss * * overlaid by slates, which — partaking the nature of the rock beneath—are micaceous or talcose as it contains mica or talc. These are at unequal intervals interlaid by thick-flaggy quartz-rocks; which “ to the south of the mine, a thick bed of a highly crystallized stratified lime- “ stone crops out at the same angle, and in the same direction as the other rocks. “ About half a mile to the eastward of the entrance to the mine, the bed of “ Jacotinga narrows to a point, but towards the west it appears to be inexhausti- “ ble.— Virgil yon Helmreichen, Gardner's Travels in the interior of Brazil, p. 494. Henwood, Edinburgh New Philosophical Journal , L. p. 61. * AMonlevade pres Santa Barbara “ nous avons dans la partie inferieure une “ couche puissante d’amphibole et de feldspath vient ensuite le gneiss, puis apres “ le schiste talqueux et micace, parseme de veines de quartz, puis le gres elas- “ tique, sur lequel repose une couche de Jacutinga et de fer oxvdule (le plus “ riche), qui a plus de 50 pieds d’epaisseur; puis du gres, puis d’autres couches “ de fer, &c.”— M Jean Antoine de Monlevade, MSS. von Spix und von Martius, Reise in Brasilien , i. p. 352. von Eschwege, Annales des Mines , viii. pp. 401-430 ; Pluto Brasiliensis, p. 210. “ The Morro da Villa Rica consists almost entirely of a primary quartz-slate, “ resting on gneiss and mica-slate. Occasionally clay-slate intervenes between “ the gneiss and quartz-slate, and sometimes the mica-slate is entirely wanting. “ * * * The quartz-slate puts on a variety of aspects. Very low down it con- “ tains a large portion of mica and the grains of silex are more regular. * * * “ Higher up in the mountain it partakes more the character of a simple rock; “ being tolerably compact, granular, and stained in spots with iron. The grains “ are occasionally as large as small peas, and enveloped in a finer matter. This “ formation is intersected by veins and nests of quartz, which do not seem to “ have in any way disturbed the stratification of the rock. Contrary to what is “ generally remarked of quartz-rock, this formation is eminently metalliferous, “ and the numerous holes and excavations made in the veins of quartz have “ been rewarded by the discovery of large quantities of gold. * * * “ About two hundred feet up the mountain large masses of talc-slate are em- “ bedded, and frequently cover the rock just described. This slate is of a “whitish or lead colour; and immediately in contact with it, another rock, “ which I have named a ferro-micaceous slate, is generally seen to rest. Some- “ times this slate has only a very slight tinge of iron; at other times it exists “ perfectly decomposed, and puts on the appearance of decayed wood. Fre- “ quently the mica appears completely lost; and the slate takes the character of “micaceous iron, and is essentially an ore, and worked as such. When it “ assumes this form, a blow with a hammer on the strata causes a quantity of “ fine sand to issue from between the laminae. In some spots one or other “ of these beds is often wanting.” Caldcleugh, Travels in South America , n. pp, 259-261. 172 W. J. Henwood, on the Gold-Mines are likewise micaceous in some places but talcose in others.* Clay-slate, which passes at times into chlorite-slate, succeeds the mica and talc slates, and includes also large masses of quartz. In many parts of the next formation granular quartz, mixed occasion¬ ally with a small proportion of lime, is interlaminated with mica or talc; f but in others these are replaced by thin bands of specular J or oxydulated iron-ore. * “ Les lamelles de talc ou de chlorite se joignent si bien les unes avec les “ autres, en entourant les graines de quartz, que la roche devient souple; c’est “ ce que l’on a appele gres flexible ou elastique du Bresil.” yon Eschwege, Annales des Mines, vm. p. 411. Mawe, Annales des Mines , iv. p. 234. von Spix und von Martius, Reise in Brasilien, I. p. 352. Caldcleugh, Travels in the interior of Brazil, n. p. 260. Claussen, Bulletins de VAcademie Royale des Sciences de Bruxelles, vm. (Ire partie) p. 325. f “ L’itacolumite est de meme age que le thonschiefer primitif, le schiste “ ferrugineux, le talc, la chlorite schisteuse, l’itabirite et le calcaire primitif. “ * * * Les parties essentielles de cette roche son le quartz et le talc, ou la “ chlorite. Le tissue est schisteux, a grains gros, moyens ou petits, suivant “ que le talc ou la chlorite domine et s’y trouve en lamelles comme le mica dans “ le mica-schiste.” von Eschwege, Annales des Mines, vm. pp. 410-411; Pluto Brasiliensis, p. 218. von Spix und von Martius Reise in Brasilien , I. p. 353. Caldcleugh, Travels in the interior of Brazil, n. p. 260. Claussen, Bulletins de VAcademie Royale de Bruxelles , vm. (Ire partie) p. 325. von Helmreichen, Gardner's Travels in the interior of Brazil, p. 498. Murchison, Geology of Russia in Europe and the Ural Mountains, i. pp. 381, 481. Henwood, Edinburgh New Philosophical Journal , l. p. 61. Itabirite. Du fer oligiste micace (eisenglimmer) , du fer oligiste en g6n£ral “ compacte plus rarement feuillet^, un peu de fer oxiduld et de quartz dissdminds, “ composent cette roche, qui est tantot solide et compacte, tantot d’une texture “ grenue-schisteuse. * * * Toutes ces masses sont magn^tiques et meme “ magnetipolaires. * * * Ce nom est d£riv6 de celui du pic d'ltabira, non loin “ de Sabarct." — von Eschwege, Annales des Mines, vm. pp. 417-419; Pluto Brasiliensis, p. 222. De Monlevade, Annales des Mines, iv. p. 137. von Spix und von Martius, Reise in Brasilien , i. p. 404, Caldcleugh, Travels in the interior of Brazil, ii. p. 261. J. C. Hocheder, Reports of the Imperial Brazilian Mining Association, xv. (1833) p. 54. Claussen, Bulletins de I’Acadlmie Royale de Bruxelles, vm. (Ire partie) p. 327. von Helmreichen, Gardner's Travels in the interior of Brazil, p. 494. Henwood, Edinburgh New Philosophical Journal, L. p. 61. of Minas Geraes , in Brazil 173 ♦ Sometimes, however, the iron-ores — slightly mixed with other ingredients—form beds of enormous thick¬ ness.* * * § Hornblendic rocks']' potstone,^ and dolomite § occur amongst the upper slates. * “ The constituent parts of the Jacotinga are iron-mica and quartz ; the latter “ usually in a state of disintegration. * * * Manganese, scaly talc, and massive “ iron glance are its chief accidental ingredients; and of these the first occurs “in layers from one quarter of an inch to two or three inches in thickness; “ whilst the other two are embedded in irregular strings and nests. J. C. Hocheder, Reports of the Brazilian Mining Association , xv. (1833) p. 54. von Eschwege, Annales des Mines , vm. p. 417. Claussen, Bidletins de VAcademic Royale de Bruxelles , vm. (Ire partie) p. 327. von Helmreichen, Gardner's Travels in the interior of Brazil , p. 494. Henwood, Edinburgh New Philosophical Journal, I. p. 61. f “ TJn fait remarquable est le passage de le thonschiefer au griinstein, qui y 0-0000108 J 1856 , July. 1857 , March .... 315*768 315*564 0*0000201 0 0000201 190*113 172-740 0*0000121 > 0*0000110 5 1856 , April. 1857 , February .. 1858 , August.... 318*645 318*756 318*700 0*0000203 0-0000203 0 0000203 193*821 ] 82*754 168*922 0 * 0000124 ') o * ooooii 7 y 0*0000108 } 1860 , February .. ,, March .... 405*458 405-956 0*0000259 0*0000259 272*555 300*995 0-0000174 > 0 0000192 5 1860 , January .. „ August.... 424-381 424-159 0-0000270 0-0000270 261*323 290*925 0-0000167 > 0*0000185 } 1855 , 7 months .» 1860 , whole year , 431-020 433-565 0*0000274 0*0000276 217*321 292*976 0-0000139 > 0*0000187 $ * Reports of the Saint John d'el Rey Company , xxvii. 1856, p. 40; xxviii. 1857, p. 47; xxix. 1858, p. 43; xxx. 1859, p. 43; xxxi. 1860, p. 48. Table VI.a f Table VII. , column 25. of Minas Gerais , ira Brazil . 199 Although some of these discrepant results may have been affected by occasional modifications in the process of reduction, they chiefly depend on the greater or less ease with which gold is freed from the various ingredients of its matrix, in different parts of the mine. (b 1.) The hardness of metalliferous deposits, has such a relation to the ores they contain, # that—ir¬ respective of any obstacles or facilities it may present •—it is an object of paramount interest to the miner. Annual accounts of—the ore extracted,')'—the depths whence it was obtained,')'—the holes bored,')'—and the workmen employed in blasting,')' supply means for comparing the hardness of the metalliferous mass at Morro Velho. Dept! Extremes. fms. LS. Means. fms. Holes bored; per man, per day. Tons of crud per man, per day. e ore broken; per hole. 50* to 100* 100* „ 123*8 86*3 123*8 0*864 0*920 1*027 1*139 1-182 1-237 Mean of eleven ) years.$ 11354 0-9064 10-084 1-2224 * Borlase, Natural History of Cornwall , p. 152. Jars, Voyages Mitallurgiques hi. pp. 86, 190, 195. Pryce, Mineralogia Cornuhiensis, pp. 89, 91-94. Werner, New Theory of the Formation of Veins, p. 122. Daubuisson, Des Mines de Freiberg, I. p. 53; in. pp. 56, 153, 243, Phillips, Gcol. Transactions, n. p. 132. Carne, Cornwall Geol. Trans., hi. p. 80. Pox, Report of the Royal Cornwall Polytechnic Society , 1836, p. 86. De la Beche, Report on the Geology of Corn¬ wall , Devon, and West Somerset, p. 336. Henwood, Cornwall Geol. Trans., v. pp. 183, 212, 221, 224, 226, 228, 230; vi. p. 145; Ante, pp. 84, 125. “ An experiment of single-handed boring was tried, but failed from the ex- “ cessive hardness of the lode.”— Mr. Herring, Reports of the Saint John d'el Rey Company , vm. 1837, p. 23. “ The system of boring with ‘ jumpers ’ has been tried, by a man who pro- “ fesses to be an experienced hand, and he signally failed.” Captain Treloar, Ibid, xxiv. 1853, p. 27. t Reports of the Saint John d'el Rey Company, 1850—1860. Table VII., columns 2, 5, 6, 7, 8. X Table VII., columns 2, 5, 6, 7, 8, lines 29, 30, 31. G G 200 W. J. Henwood, on the Gold-Mines The progressively larger quantities of ore pulverized A comparison of the means employed with the work accomplished in the broader parts of different mines may not be out of place here. © A 3 < cr* co w 4 c*2 PS ♦H 44 IS £ ~ c-° eo « *2 O ''o ft? a 1 C0 m tT CD o . P? CQ £2 M la *-3 ty at m a o o *1 o a w .32 .2 a 02 a >1 o 60 « Vi o pH ci o PS ci co . ci 02 a m |a H * CO fl *3 ^4 a _ o P.H c3 o c2 A d b* H .a 02 «f 02 O e blasted; per lb. (Avoir) of gunpowder. Tons. CO cp o 009-1 5-814 1-327 1-333 0-666 Vein-ston per man, per day. Tons. 1-108 0 H Cl / 1-287 0-750 0-750 (uioay) *qi •Inp-iod unra.iad pasn jopModunj) oo CO o 0-625 CO o 0-970 0-562 1-125 •soipui •inp aad unni aad paaoq epq jo qjdaa 28-5 00 TiH o o Cl N kp ko • jo japmnra *5 r i 0) d da o O 'H c3 oT d d • /-N gJ 9^*4 in • w . gT a Ifl iT ps - «2 ~ ^ to tSJ *7? O H £ " ° o o PS a> r—< > c3 > C3 O d cn i >* c3 s 53 i . . 13-11 . Total yield by every method. grains. _ 230-72 - 220-21 .... 194-76 _ 164-33 _ 172-40 _215-84 .. .. 293-08 Reports of the Saint John d'el Reg Company, xxv. 1854, p. 34; xxvi. p,41; xxvn. p. 40; xxviii. p. 47 ; xxix. p. 43 ; xxx. p. 43; xxxi. p. 48. 204 W. J. Hen wood, on the Gold-Mines The following columns contrast assays of ore pre¬ pared for the stamps with the proceeds of its reduction. Tt< X X X CD p. X M X X *0 w 10 « *> > 1—1 X *-• r”) to $ a PH S Ptj « t)H ^ P< CO .. £ s CO 53 fcoi V< « . cx pL, Si O § S |2 <0 • ^ X 3 £ % » * of Minas Geraes , in Brazil. 205 Since monthly assays of ore prepared for the stamps were established* in 1855, the loss of gold during reduction has been diminished (from 48*92 to 32*41) 16*51 per cent.; a difference which now affords profit from ore which could formerly have been wrought only at a loss. Meanwhile the mine was deepened (from 116*6 to 142 81) 26*2 fathoms. The assay of ores obtained from so small a vertical range affords but little aid in ascertaining any differ¬ ences of quality prevalent at various depths in the metalliferous deposit. The proportionate yield of gold, from ores extracted at different depths, has been, Gold. Depth. Proportion yielded by Crude ore. Ore made ready for fms. the stamps. Surface to 50* 1* 1* 50* „ 100* 0*956 0*888 100*,, 142*8 .. 0*912 0 865 Thus, as the mine was deepened, its ores yielded a gradually smaller proportion of gold. (b 3.) Meanwhile, more efficaceous appliances col¬ lected larger quantities of amalgamate ore, which afforded, progressively, gold of greater fineness.J Quality (toca) of Gold. Depths. Actual. Comparative, fins. Carats, grains. Surface to 50 18 3-687 . 1* 50 „ 100 19 0-183 . 1-006 100 „ 142-8 . 19 0-288 . 1-008 (Jb 4.) The quantity of silver obtained was greater * By John Hockin, Esq., Managing Director of the Saint John d’el Rey Company. t Table VII., column 2. X Table VII., columns, 2, 28, 29, 30. 206 W. J. Henwood, on the Gold-Mines also, as the gold it had been associated with was ex¬ tracted from more deeply-seated ores.* Silver in unrefined gold, Depths, Grains of, Proportion fins. lb. (Troy). of mass. Comparative. 50 to 100 1,108*1 0*1924 _ 1* 100 „ 142*8_ 1,131*2_ 0*1998 1*02 Mean. 1,118*4_ 0*1942 — The results obtained in several foregoing pages, are compared in the following columns. Depth. fms. Width o BahiX. f formation. Cachoeira. Hardness of vein-stone. Ric Crude ore. hness of Ore prepared for stamps. Quality of gold. Silver. Surface to 50* 1- 1- -1 1- 1- 1- -t 50- „ 100- 1-050 1-932 1* 0-956 0-888 1-006 1* 100- „ 142-8 1-482 2:077 0-902 0-912 0-865 1*008 1-020 Thus, to a depth of 142*8 fathoms the vein-stones are softer, and the silver is more plentiful; yet—owing to the still smaller proportions of other foreign sub¬ stances,—the gold is of better quality, in deeper, than in shallower, parts of the mine. (5-5.) Whether parallel, oblique, or transverse, in direction, to the schistose structure of the adjoining slates, the formation and its branches have—with trifling exceptions—a prevailing inclination to the south .I Meanwhile the several rich masses or hunches of auriferous pyrites in the Baku , the Cachoeira , and the Gamha as well as the bodies of unproductive vein¬ stone between them, have an end-long dip or shoot * John Hockin, Esq., Managing Director of the Saint John d’el Rey Company, MSS. Table VII., columns 2, 31. f Unrecorded. $ Ante, p. 188. of Minas Geraes , in Brazil. 207 of seldom less than 43°, but never more than 47°— towards the east,* ** obedient to both these inclinations, and dipping with the neighbouring slates;—the Bahu 9 Cachoeira, Catta Branca stopes and other portions of the formation, are, at the bottom of the mine, one hundred and forty fathoms south-east of their counter¬ parts at the surface (Pl. III.). Whether the metalliferous deposit — partaking, as usual, the nature of the neighbouring rocks—be faced by the edges of their laminae and bounded by joints; or—interlying them—conform to their flexures; its sides, and the faces (walls) of slate adjoining them, produce undulations, flutings, grooves, and strice which coincide as well with the schistose structure, as with the shoots or hunches of ore and masses of vein-stone in \ general dipj: towards the south-east. * “ The whole mass of lode and its branches, move bodily forward and down- “ ward in a nearly true east direction.” Mr. Herring, Reports of the Saint John d'el Bey Company , ix. (1838) p. 29. “ The dip of the lode itself carries the whole mineral deposit 5 feet 10 inches “ to the east, for every 6 feet that is sunk.— Ibid, xi. (1840), p. 34. “ Four well-marked enlargements of the metalliferous deposit at Morro Velho, “ respectively preserve the same relative positions, the same configuration, and “ indeed almost exactly the same dimensions to the depth of 42 fathoms, as they ** expose in their outcrop at the surface. They have a regular inclination of “ about 45° towards the east, on a line which bears 2° S. of E. & N. of W; and “ this regularity equally prevails whether the dip of the formation may be paral¬ lel or oblique to the cleavage of the containing rock.” Kenwood, Cornwall Geol. Trans, vi, p. 146, PI. I.; London, Edinburgh , and Dublin Phil. Mag,, 3rd series, xxv. (1844) p. 343. “ Its general direction approaches to east and west; its underlie varies from “ south to north, but averages 83° towards the south. The direction of its dip “ varies from south 58° east to south 82° east, and the inclination from 42 to 47°.” Captain Treloar, Reports of the Saint John d'el Rey Company , xxvn. (1858) p. 26. f Ibid, xxiv. (1853) p. 32. % “ Certain ‘ slides ’ of ground * * * which accompany the * * * dip of the H H 208 W. J. Henwood, on the Gold-Mines Between 30th November, 1834, and 21st March, 1862,* lbs. (Troy) Morro Velho yielded .... 59,098-654* of gold, worth £2,229,487;* of which there was paid to the Government of Brazil as lbs. (Troy) Provincial duties, 2,211*820, worth £86,391 Export duties, .. 54-868, „ 2,143 2,266*688 ,, „ 88,534. The remaining. lbs. 56,831*966 ,, realized £2,140,953 The-expenditure, from 1st Jan., 1838, to 31st May, 1862, amounted to £1,472,327 * „ loss in 1854—7. „ 6,889 1,479,216 „ net profit therefore was ... £ 661,737. * Of this magnificent sum, a portion (augmented by accumulated interest to thirty-five thousand three “ shoots of ore * * * have been exceedingly regular.”—M r. Herring, Ibid, xiii. (1842) p. 36. “ A circumstance of value to the miner, as well as of interest to the geologist, “ —common to most, if not all, the Brazilian mines worked in schistose rocks,— “ is that, whether the veins may be parallel, oblique, or transverse to the laminae, “ their sides (walls) are grooved or fluted with large strice, which coincide with “ the dips of the shoots of gold, both in the amount and in the direction of their “inclination.”—H enwood, Cornwall Geol. Trans, vi. p. 146; London, Edin¬ burgh, and Dublin Phil , Mag, 3rd series, xxv. (1844) p. 343. The dip “ is every where parallel to the striae.”—C aptain Treloar, Reports of the Saint John d'el Reg Company , xxvii. (1857) p. 27; xxvm. (1358) p. 44. * The results of operations at Morro Velho during the year 1861 were,— Crude ore broken in the Mine. Tons. Rubbish rejected. Tons. Ore stamped. Tons. Gold. _ Grains in each ton ( Avoir.J of ore. Quantity extracted, lbs. ( Troy.) 96,612*2 a t 24,033-6 71,902*4 383-99 5,050-907 From 19th March, 1861, to 21st March, 1862,— 5,200*689 lbs. {Troy) of gold were obtained; which realized.£212,813 The expenditure for the year ending 31st May, 1862, was. 116,044 From 19th March, 1861, to 21st March, 1862,— 5,200*689 lbs. {Troy) of gold were obtained; which realized.£212,813 The expenditure for the year ending 31st May, 1862, was. 116,044 The profit therefore amounted to ... £ 96,769 a Crude ore unstamped, 686-2 tons. Reports of the Saint John d'el Rey Company , xxxn. (1861) pp. 5, 22, 24, 25, 57, 59, 60. of Minas Geraes , in Brazil . 209 hundred and seventy-three pounds) forms a Reserved Fund; # —nineteen thousand five hundred and seven pounds have been transferred to the Capital Account; —and five hundred and fifty-eight thousand two hun¬ dred and fifty pounds have been divided amongst the fortunate shareholders. From every part of this district—formerly a rich one,')' gold is still obtained; but the other mines J now wrought are small and poor. (IV.) (a.) At Ouro Preto § buff-coloured, granular, * Reports of the Saint John d’el Rey Company } xxxn. (1861) p. 19. f Southey, History of Brazil, in. pp. 56, 283. Mawe, Travels in the interior of Brazil, p. 386. Caldcleugh, Travels in South America, ii. pp. 273-7. von. Spix und von. Martius, Reise in Brasilien, ii. p. 417* * * § von Eschwege, Pluto Brasiliensis, pp. 16, 441; Tabellarische Uebersicht alter Gold lavaras jeden Dis¬ tricts in der Provinz Minas Geraes, pp. xin.-xvn. Saint Hilaire, Voyage dans le district des Diamans, et sur le littoral du Brasil, ii. p. 168. Claussen, Bulletins de VAcademie Royale de Bruxelles , vin. Ire partie, p. 323. Gardner, Travels in Brazil , p. 495. Henwood, Cornwall Geol, Trans, v i. p. 143; London, Edinburgh, and Dublin Phil. Mag., 3rd series, xxv. (1844) p. 341. J Attempts to work ill-ventilated parts of Bella Fama by the light of fire-flies were made by Colonel Trolle ; but without success. MSS. of the late John Henry Belden, Esq., M.D., of Sahara. § “ Villa Rica (Ouro Preto) a si peu de regularity, qu’il est extremement diffi- “ cile d’en donner une id£e tres-exacte. Elle est batie sur une longue suite de “ mornes qui bordent le Rio d’Ouro Preto et qui en dessinent les sinuosit£s. Les “ uns sont plus avances; d’autres recules davantage forment des gorges assez “ profondes; quelques-uns, trop a pic pour recevoir des habitations, ne pr£sentent, “ au milieu de ceux qui les environnent, qu’une v5g£tation assez maigre et de “ grandes excavations. Les maisons se trouvent ainsi disposees par groupes “ inegaux, et chacune est, pour ainsi dire, construite sur un plan different. La “ plupart ont un petit jardin long et etroit, assez mal soigne. Ces jardins sont “ soutenus par une muraillepeu 61evee, presque toujours couverte d’une immense u quantity de fougeres, de graminees, de mousses, et le plus souvent ils forment “ les uns audessus des autres une suite de terrasses dont l’ensemble presente “ quelquefois une masse de verdure, telle qu’on n’en vit jamais dans nos climats “temp^res. De ces maisons ainsi entremelees de sommets arides et de touffes “ serrees de v^getaux, il rdsulte des points de vue aussi varies que pittoresques “ mais la couleur noiratre du sol, celle des toits qui n’est guere moins obscure, 210 W. J. Henwood, on the Gold-Mines flags (“ the elastic sandstone of Villa Rica ” * * ), com¬ posed of quartz and mica, are overlaid by thick lamellar, homogeneous, soft, blue clay-slate, of silky lustre; of which, the upper members,—often darker in colour,— are, at intervals, shaded with either pink, red, or brown. Although the clay-slate is seldom destitute of gold, the more deeply tinted portions only contain enough to pay the workman: from these, however, some few poor people still obtain a scanty livelihood. “ le vert fonc6 des orangers et des cafiers tres-multiplies dans les jardins, un ciel “ presque toujours nuageux, la stdrilitd des mornes oil l’on n’a point bati, com- “ muniquent au paysage un aspect sombre et mdlancolique. ****** * “ Les petits jardins * * * sont generalement assez mal soignds. Des orangers, “ des caf£yers, des bananiers, y sont plantds presque toujours sans ordre. Les “ choux sont le principal legume qu’on y cultive; et, parmi les fleurs, celles qui “ ont le plus de vogue sont les ceillets et la rose de Bengale, qui a conserve sa “ couleur primitive.” * * * * * * “ Dans la valine oil nous etions descendus, coule le Rio d’Ouro Preto, petite “ riviere dont les eaux, peu abondantes, sont sans cesse divisee et subdivisees par “ les chercheurs d’or, et dont le lit d’un rouge noir ne presente plus que des filets “ d’eau qui coulent entre des amas de cailloux noiratres, residu des lavages.” Saint Hilaire, Voyage dans les Provinces de Bio de Janeiro, et de Minas Geraes, I. pp. 137, 139, 149. Mawe, Travels in the interior of Brazil, pp. 238-9. von Spix und von Martius, Beise in Brasilien, I. pp. 368-9. Southey, History of Brazil , in. p. 56. Walsh, Notices of Brazil, ii. pp. 191-195. Gardner, Travels in Brazil , pp. 509-512. * Caldcleugh, Travels in South America, ii. p. 259. von Eschwege, Annales des Mines, viii. (1823) p. 411; Pluto Brasiliensis , p. 218. “ Der quartzreiche, kornige Glimmerschiefer, Gelenquarljs, elastische Sand- “ stein oder Quartzschiefer vom Morro de Villa Bica besteht aus einem graulich- “ und rothlich-weissen, nich selten auch rauchgrauen, fein-und sehr feinkornigen “ Quartze und aus einem silberweissen, mehr oder weniger dunkelperlgrauen, ‘^selten tombackbraunen, sehr zartschuppigen Glimmer, welcher nicht selten auf “ d'en Schichtungsablosungen durch Eisenoxyd roth gefarbt ist. Der quartz “ verliert zuweilen sein korniges Gefiige, und bildet schmale Schichten von “ dichtem splittrigen Bruche; eben so hauft sich nicht selten der silberweisse “ Glimmer auf den Ablosungen in oft einen halben Zoll dicke, wellenformig “ gebogene Schichten zusammen, und nimmt sodann einen ausgezeichneten “ Perlmutterglanz an. VON Srix END VON Martius, Beise in Brasilien , i. p. 352. of Minas Geraes , in Brazil. 211 ( [b .) Granules of quartz and small lenticular masses of mica # form a pale brown or yellowish buff coloured rock;f which—both at Ouro Preto and Gongo Soco% —succeeds the auriferous clay-slate, yet affords little or no gold. The planes of deposition and cleavage,—parallel throughout the district,—here bear 10 Q ~20° N. of E. k. S. of W., and dip 20°-38° S.; whilst the principal joints range 10°-20° E. of N. & W. of S. (V.) (a) The thick-lamellar rock which succeeds the mica-slate and conforms to its foliation, is composed, for the most part, of granular quartz and iron-ore in alternating, layers; § sometimes several inches, but * “ In many cases * * * § * * flexures * * * involve the laminae of which the “ stratum is formed, without affecting the stratum itself.” Macculloch, Classification of Rocks, p. 268. Bakewell, Introduction to Geology (4th Edit.), p. 104. f “ Diese * * * Bildung des quartzigen Glimmerschiefers liegt auf Thon- “ schiefer auf, welcher, nach seinem zu Tageausgehen in den tiefsten Puncten “ des Thales von Oiro-Pxeto, die Grundlage des Morro auszumachen.” von Spix und von Martius, Reise in Brasilien, i. p. 344. “II alterne en bancs puissants et sur une grande etendue avec le thonschiefer.” von Eschwege, Annales des Mines, vm. p. 411. \ Ante, p. 182. § “ Schiste ferrugineaux (Eisenglimmer schiefer) Les parties essentielles de “ cette roche sont le fer oligiste micac6 (eisenglimmer) et le quartz. Son tissu “ est grenu-schisteaux, ordinairement lache; on trouve cependant quelquefois “ des couches solides. Le fer oligiste domine et donne a la roche une teinte de “ fer oxide plus ou moins foncde ; elle est quelquefois divis^e en feuillets d’une “ grande tenuit6 : le fer et le quartz sont alors treis-distincts, ce qui produit une “ apparence rubanee de couleurs alternativement blanches et sombres. Les “ particules de quartz sont en general peu adherentes; elles se detachent de la “ surface, qui parait alors criblee de petites cavites: d’autres fois elles sont tres- “ disseminefes; la masse entiere prend alors un aspect tachete. Le fer oligiste “ presente le plus souvent un eclat tres-vif; les fuillets minces de la roche sont “ quelquefois flexibles.” von Eschwege, Annales des Mines, vm. p. 413; Pluto Brasiliensis, p. 222. > 21-fm. level .. — • • — 510 t Stokes’s >> 7-fm. level .. 17*5 $ 14-fm. „ .. 17 0$ Lyon’s >t Surface 20-0 || 7-fm. level ) 21-fm. ,, S 15*011 27-fm. „ ) 41-fm. „ J 14*0 H Gibson’s 27-fm. level .. ("Divided by a {horse) mass of ty < rock ; which widens both in 1 depth & towards the east.** North South part. part. 0*50 2*8 34-frn. level .. 2*6 tt 2*0$$ 41-fm. ,, .. ( Isolated masses, 1 t 0*10 > 48-fm. „ .. 0*08 mi Bayly’s t> 34-fm. level .. 2*0irir 41-fm. „ .. f Isolated nests. *** * 0*06 48-fm. ,, “ • • — 15*0 ttt 55-fm. ,, .. ■ “ 1 • • 0 6 8-2 m 8*8 * Hocheder, Reports of the Imperial Brazilian Mining Association , xv. (1833) p. 54. t Trebilcock, Hambly, & Prideaux, Ibid, vm. (1829) p. 80. Hocheder, Ibid xv. PI. I. fig. 1; xvii. (1834) p. 83. von Helmreichen, Harris, Collins, Blarney, and Pengilly, Ibid, xxx. (1840) p. 84. $ Harris, Bray, Collins, Blarney, and Pengilly, Ibid, xxix, (1840) p. 51, § Hocheder, Ibid, vm. PI. I. fig. 2. || Edwards, Ibid, i. (1825) p. 20. IT Hocheder, Ibid, vm. PI. I, fig. 3. ** Table VIII. column 21. ft Hocheder, Reports of Imperial Brazilian Mining Association , xvii. p. 119. it Ibid, xvii. p. 101. §§ Ibid, xvi. p. 47. HI Tregoning, Harris, Bray, and Collins, Ibid , xxn. (1836) p. 111. Iffl Hocheder, Ibid, xvi. p. 47. *** Ibid, xvii. pp. 101-4. ttt Tregoning, Ibid, xvm. (1834) PI. I. fig, 1. iU Harris, Bray, Collins, Blarney, and Pengilly, Ibid, xxvili. (1839) p. 59. 254 W. J. Henwood, on the Gold-Mines Locality. Depth. Qongo formation. Breadth, fms. Cumba formation. Breadth, fms. Total. Breadth, fms. North South part. part. Vesey’s shaft. 48-fm. level .. J • • 2-0* 55-fm. ,, n ~~ ' • • 0* * § 6 7-51 8-1 62-fm. „ • • 02 + § 70-fm. ,, E. 1 • • 0-2 § § 80-fm. ,, E. " 1 • • 0-051| II Thus, within a range of six hundred fathoms, the northern or Gongo deposit dwindles from about 80 fins, to a few inches; and the southern or Cumba „ „ 75 „ to about 7| fathoms in thickness. (3—3.) The Gongo formation consists, for the most part, of micaceous and massive iron-glance; more or less mixed, however, with oxydulated iron-ore towards the east.** From Angove's shaft to Pengilly's, and again, from Duval's to Allcock's (PL II. Fig, 2), the other ingredients are interlaminated with earthy brown iron-ore; which between Pengilly's and Duval's is mingled with,—and between Allcock's and Aveline's shafts is replaced by,—earthy black iron-ore; whilst smaller quantities of both occur elsewhere. Great part of the Gongo formation is irregularly sprinkled * Hocheder, Reports of the Imperial Brazilian Mining Association, xviii. p. 46. f Harris, Bray, Collins, Blarney, and Pengilly, Ibid, xxvm. p. 59. X von Helmreichen, Harris, Collins, Blarney, and Pengilly, xxx. p. 81. § Henwood, Ibid, xxxix. (1845) p. 10, || Ibid, xl. p. 11; xli. (1846) p. 9. If von Eschwege, Annales des Mines, vm, (1823) p. 413. Edwards, Reports of the Imperial Brazilian Mining Association, i. (1825) p. 20. Hocheder, Ibid, xv. p. 54. Claussen, Bulletins de V Academie Roy ale de Bruxelles, vm. lrepartie (1841) p. 327. von Helmreichen, Gardner's Travels in Brazil, (1846) p. 494. Henwood, Edinburgh New Phil. Journal, l. (1851) p. 61. ** von Eschwege, Annales des Mines, vm. p, 413, of Minas Geraes , in Brazil . 255 with gold; * * * § which, however, is seldom abundant enough to be worth separation. Ore obtained at a distance of several fathoms from the chief auriferous (veins) bands, yielded—when stamped —the under¬ mentioned proportions:— Gold. r--> Date. Grains, per ton (Avoir.) Proportion. of ore. 1837... 1850, July—December 1851, January—June.. „ September. 0*000000422 ; t 0*000000765; % 0*000000415; 0*000000510; 0*000000191. Laminae and small irregular beds of buff-coloured talc also conform to the complicated volutions which are numerous in the bands of iron-ore they interlie; and—towards the east especially—face every joint and seam. Quartz is neither a congenial matrix,|| nor even a constant ingredient amongst the richer ores; * In Lyon’s shaft the Jacotinga at fourteen fathoms from the vein answers for stamping; and this is also the case at considerable distances in other parts of the mine.— Harris, Jeffery, Bray, Jennings, & Collins, Reports of the Imperial Brazilian Mining Association , xiv. (1832) p. 71. “ Part of the ore stamped is brought from the cross-cuts; which, although it “ yields a little gold, is poor compared with that taken from the veins.” Tregoning, Harris, Bray, & Jennings, Ibid, xviii. (1834) p. 84. " At the 41-fm. level, near Bayly's shaft, the Jacotinga , three fathoms north of the vein, shews a little gold when washed. Tregoning, Bray, Harris, & Simmons, Ibicl, xix. p. 51. f Tregoning, Harris, Bray, and Collins, Ibid , xxn. p. 120. t Walker, Ibid, L. p. 3. § “ These trifling contents of gold per ton of Jacotinga prove the * * * in- “ expediency of incurring the outlay of much, if any, further capital.” Waller, Ibid, li. pp. 4, 5. The deposition of gold in Jacotinga has no relation to the quartz formation “ of the country.”— Hocheder, Ibid, xyii. p. 51. || Ante, p. 229. 256 W. J. Hen wood, on the Gold-Mines but—generally mingled with talc, and mixed with either iron-glance, oxydulated iron, iron-pyrites, or, more largely and more generally with earthy pale- brown iron-ore,—it is a chief constituent of the barren and contorted beds into which the auriferous strata gradually pass towards the east. That part of the Cumba formation which was, for many years, wrought by the native proprietors as an open-work (Talho Aberto)* at Canta Gallo , imme¬ diately west of the mine,f consists, in great measure, of micaceous iron-glance; interlaid, however, by thin beds of granular quartz, tinged with earthy brown iron-ore. Near Blarney's and Collins's shafts the iron-glance — rarely massive,J sometimes granular, but generally micaceous — is often disintegrated, and largely, yet irregularly, mixed, as well with earthy black and brown ore, as with clay. From Luke's to * Table VIII., column 3. f The Jacotinga which has been worked at Canto Gallo by the native pro¬ prietors bears about 20° N. of E. & S. of W., dips 35° S., and, in its range towards the east, appears to rest on the Gongo formation. In one spot, at which opera¬ tions have been lately resumed, those “ layers which are most associated with “ the oxide of iron, contain more gold than others with less oxide, and in those “ in which no oxide of iron exists I could detect no gold at all, or only a trace “ in the samples.” * * * In a second spot, w'hich has for many years been un¬ interruptedly prosecuted as an open-work ( Talho Aberto) a few negroes have been employed in “ cutting down the whole mountain into the river, and con- “ ducting the water with the stuff * * * over Strekes covered with hides. The “ gold existing in both these open-works is very minutely disseminated through the entire body of the rock; consequently the whole must be quarried and “ stamped.” The proportion of gold is, however, “ so inconsiderable, that it is “ my firm conviction this mode of working, or rather the formation so worked, “ can never be an object to an English Company.”— Hocheder, Reports of the Imperial Brazilian Mining Association, xvii. pp. 84-6. von Helmreichen, Harris, Collins, Blarney, and rengilly, Ibid, xxx. pp. 84-G. t Hocheder, Ibid, xvii. p. 105. of Minas-Geraes, in Brazil. 257 Crickitt's, and thence eastward to the cross (drift) -cut south of Jennings's shaft, the earthy ores affect separate beds, # but—indistinctly bounded—they mix by degrees with iron-glance at the sides. From the meridian of Jennings's shaft eastward the iron-glance is, to some extent, replaced by oxydulated iron, but earthy black and brown iron-ore are still common; quartz, also, either forms small irregular layers,')' or is mingled with the clay, which—everywhere abundant—is, at intervals, the chief ingredient. Talc is much more plentiful in this formation than in that below; but, whilst generally disposed in isolated masses and short, thin, conformable beds, it is sometimes the principal constituent. Between Canta Gallo and Collins's shaft the particles of gold imbedded in the rock enclosing several short, thin, narrow bands,J which have afforded, at intervals, a few bunches § of rich ore, are larger * Harris, Bray, Blarney, and Pengilly, Reports of Imperial Brazilian Mining Association , xxviii. p. 62. f Tregoning, Harris, Bray, and Collins, Ibid, xix. p. 47; xxt. p. 92. X A cross-cut at the adit in Cumba has intersected several veins, but they are all poor.—T rebilcock, Hambly, & Prideaux, Ibid , vm. p. 80. “ the Cumba formation there are various auriferous veins.” Harris, Bray, Blamey, & Pengilly, Ibid, xxvn. p. 60. We have had in Cumba as many as three gold-veins side by side in the same workings, which are here no less than nine or ten feet wide; and in addition to the rich ores, which are taken in boxes to the washing-house, the ore for a con¬ siderable width beyond the veins will give a good produce at the Stamps. Harris, Collins, Blamey, Pengilly, & von Helmreichen, Ibid, xxx. p. 55. § “ We have cut a vein in the Cumba which has given 4~ oz. of very fine gold, “ and still affords^n7fo ” (solid lumps) “ of small size.”—L yon, Ibid, vn. p. 31. “ had 4 lbs. from the Cumba in one day.”— Skerrett, Ibid, x. p. 27. “ At the Cumba on one occasion during the past month the vein yielded about u 2 oz. of gold for the washing-house .” Harris, Bray, Blamey, & Pengilly, Ibid, xxvn. p, 54. The Cumba mine, which has already yielded a considerable quantity of valuable 258 W. J. Henwood, on the Gold-Mines and more numerous than in other parts of the deposit. Portions of the strata, which enclosed the smallest and poorest of those bands, gave at the Stamps 0* * * * § 000017 their weight # of gold. Near the middle of the mine considerable portions of this formatiotf were laid open by levels (galleries) from Luke s f and Crickitt’s, J as well as by cross (drifts)-cwte from several other shafts; § but—though parallel to the richest part of the Gongo system ||—it yielded merely small grains of gold, far too widely scattered to repay the cost of extraction. Amongst some thousand samples taken from many eastern parts of the mine, none contained more than a barely discernible particle or two of gold.If ore for the Stamps afforded from the 26th to the 30th of October, 1840, upwards of 23 lbs. of gold for the washing-house. von Helmreichen, Harris, Collins, Blamey, & Pengilly, Reports of the Imperial Brazilian Mining Association, xxx. p. 85. * 36 tons of ore reduced in twenty-four hours yielded lib. 8oz. 19dwts. llgrs. of gold.— Duval, Ibid,xx n. p, 83. f Henwood, Ibid, xliii. p, 5. t Harris, Bray, Collins, Blamey, Pengilly, von Helmreichen, and Henwood, Ibid, xxix. pp. 38, 44,51,56; xxx. pp. 48,52; xxxi. pp. 41,43; xxxvm. p. 2; xxxix. p. 10; xl. p. 10; xli. p. 8; xliii. p. 5. § Hocheder, Harris, Bray, Collins, Blamey, Pengilly, von Helmreichen, and Henwood, Ibid, xxiv. p. 45; xxx. pp. 65, 86; xxxi. pp. 24, 27,41, 43; xl. p. 10; xliii. p. 5. || “ It is commonly believed that wherever a lode is rich, if there be another “ lode near it, having nearly the same direction, and in the same country * * * “ it is probable that the second lode will be found rich in that part which is op- “ posite to the rich part of the first lode. This is not a new doctrine: the phrase “ ore against ore is probably of earlier date than the present generation of “miners.”— Carne, Cornioall Geol. Trans., m. p. 78. Henwood, Ibid, v. pp. 215, 233. IT Hocheder, Tregoning, Jennings, Harris, Bray, Collins, Blamey, Pengilly, von Helmreichen, Crickitt, and Henwood, Ibid, xvn. pp. 69, 95; xvm. pp. 46, 56, 61, 71, 76; xix. pp. 38, 41, 45, 51, 53; xx. pp. 65, 68; xxi. p. 74; xxiv. p. 45; xxvm. p. 59; xxxiii. p. 1; xli. p. 9. of Minas Gerais , in Brazil. 259 (3—4.) In great part of both these deposits a schistose structure prevails ; which—generally parallel to the bedding and foliation of the rock beneath— bears 3°—11° N. of E. & S. of W., whilst it inclines 35°—60° S. The same lines of cleavage are common to the auriferous portions of the Gongo formation, and to the wedge-shaped (horse) mass of iron-ore and quartz, which interlies them towards the east.* Near the richer (shoots — hunches) masses of ore certain strata exhibit broad undulations (Fig . 22, A A),t which are frequently furrowed with narrower waves.J These flexures, whether large or small, have, amongst themselves, an approximate parallelism; which in some measure conforms to the slope of the goldless granite § near Caethe on the north-west; whilst—oblique to the normal direction and inclination of the beds—-they dip 8°—30° towards the east. Fig. 22. gongo soco. Flexures of the iron strata. * Ante, p. 251, Fig. 21. t “ The curves are sometimes simple, like the superficies of a cylinder.” , Boase, Primary Geology , p. 114. | “ In some cases the irregular surface of the beds is apparently due to original “ ripple-structure, which by the general movement of the mass of the rock across “ the cleavage-planes, have acquired superposed wrinkles.” Prof. Phillies, Reports of the British Association (1856), p. 388. § Henwood, Cornwall Geol. Trans., v. p. 193 ; vi. p. 146; London, Edinburgh, and Dublin Phil, Mag., 3rd Series, xxv. (1844) p. 353. Ante, pp. 207, 234. 260 W. J. Hen wood, on the Gold-Mines Subordinate portions, as well of the Gongo as of the Cumha series, however, exhibit intricate volutions, which neither affect adjoining strata nor reach even the confines of the containing bed. # At wide and irregular intervals, however, portions of the crystalline iron-glance assume a massive struc- ture.f (3—5.) Small quantities of rich iron-ore broken near Pengillys shaft,J on the Gongo formation, were smelted § at Taboleiro near the mine; but as the native * In micaceous schist “ the lesser undulations and curvatures, are, evidently, “ often independent of any corresponding change in the evenness of the bed; “ and the same probably often holds true of the more complicated, since they do “ not seem to pervade the whole mass, but rather to occupy particular spots “ among the neighbouring and less disturbed laminae.” Macculloch, System of Geology , ii. p. 160. Boase, Primary Geology , p. 114. Sorby, Edinburgh New Phil . Journal, lv. (1853) p. 138. t As we have extended the 21-fm. level west of Walker's shaft the ground has considerably altered, and now consists of hard iron stone.— Hocheder, Reports of the Imperial Brazilian Mining Association , xvn. pp. 59, 68. “ A cross-cut north of Lyon's shaft at the 48-fm. level has traversed a hard, “ massive rock, composed wholly of specular iron-ore.” Henwood, Ibid, xxxviii. p. 3. “ In the cross-cut driven towards Bayley's shaft at the 55-fm. level we have an “ exceedingly hard iron rock.”— Harris, Bray, Blamey, & Pengilly, Ibid , xxvii. pp. 51, 56. The cross-cut north of Vesey's shaft at the 48-fm. level still penetrates a very hard iron rock. Tregoning, Harris, Bray, & Collins, Ibid, xxii. pp. 98, 102. In the Cumha adit cross-cut the rock was alternately hard iron stone, and talc schistus intermingled with micaceous iron-ore.— Hocheder, Ibid, xvn. p. 83. X Captain Blamey, MSS. § The ores of Gongo Soco are rich and good, but they require a very different mode of treatment to the one adopted in this country with the argillaceous iron- ore ; one very nearly, if not, indeed, the same, with that used in Sweden. I see of Minas Geraes, in Brazil. 261 manufacturers * sold their iron more cheaply than it no reasonable doubt that, by such a process, they would give good pig-iron. Raw ore selected for analysis yielded per cent.— First experiment. Second experiment. Peroxide of iron .. 97*00 95-20 Silica. 1-60 2-57 Alumina . 1*10 2*79 Oxide of manganese . 0*60 0-71 Lime. a trace . a trace 100 30 . 101-27 The excess in analysis is occasioned by a small portion of the iron in the ore being in a minor degree of oxidation. The limestone, sent from the same place, contained very variable quantities of the accompanying rock; which introduced silica, alumina, and magnesia into the furnace. The only sample of slag from a Brazilian iron-furnace, which I have seen, was of the worst possible quality ; for it contained such an enormous quantity of oxide of iron, as to make it equivalent to a rich ore. By analysis it gave per cent.;— Metallic iron. 2*82 Protoxide of iron. 46-80 Silica . 28-00 Alumina. 5-20 Oxide of manganese. 0 30 Lime ^. 11-20 Magnesia... 5*40 99*72 Faraday, Reports of the Brazilian Mining Association, v. (1828) pp. 89-95. t The natives of Minas Geraes select for smelting that iron-ore which is free from alumina, and other impurities; break it into pieces the size of a pigeon’s egg, but do not calcine it. Lime is sometimes used in the fusion. Their furnaces are about three feet high and ten or twelve inches in diameter, and suitable pits are prepared beneath them for receiving the fused metal. The iron, having been once fused, is immediately laid on an anvil and hammered out to the required dimensions. A superintendent (feitor) and sixteen labourers select the ore and prepare the charcoal for three or four (and occasionally even for six) such furnaces; which —usually charged fifteen times and worked by a second overseer and five other persons—yield on an average two hundred and seventy lbs. of good maleable iron. The attendant expenses are wages and food of 23 people, say one shilling and three pence per day each... of two cars for conveyance of ore, charcoal, &c. of one car ,, iron ^ q 5 0 to market.$ _ £2 3 9 or rather less than eighteen shillings and two pence per (112 lbs.) cwt. Baird, Ibid , vn. p. 82. £18 9 0 10 0 262 W. J. Hen wood, on the Gold-Mines was prepared on the spot, # operations were soon dis¬ continued. (3—6.) The most important part, however,—some¬ times made up of several layers each scarcely thicker than paper, sometimes forming a single bed varying from a fraction of an inch to three or four, but seldom as much as six, inches in width, yet conforming to every flexure of the rocks adjoining—occurs near the middle of the series.f Of the narrower portions earthy brown iron and manganese are chief ingredients; but west of Pengilly's shaft at the tram and shallow ,—of Williams's at the shallow and seven fathom level ,—of Allcock's at the seven and fourteen fathom levels, —and in other western parts of the mine, these ores are often mixed with iron- glance; eastward, however, small crystals of oxydulated iron are numerous, whilst iron-glance is, perhaps, * “ We must not make iron so long as we can purchase it.”— Sk.ere.ett, Reports of the Imperial Brazilian Mining Association, xn. p. 33. The natives who manufacture iron in our neighbourhood are supplied with charcoal by their slaves at one-half the price it costs us; they are therefore able to make iron cheaper than we can. The Brazilians are accustomed to prepare their charcoal in pits ; ours, however, is made in heaps. Manufactured in either way it is equally useful for furnaces ; but heap-burnt charcoal is the most ser¬ viceable for forges. Mr. Rooke, our chief forester, calculates that (an alquiere ) 2,772 cubic inches of charcoal made in heaps, under his superintendence, costs (one hundred and fifty reis ) about four pence, three farthings.' von Helmreichen, Harris, Collins, Blamey, & Pengilly, Ilid, xxx. p. 88. f About the middle of the disintegrated iron-mica schistus manganese—largely mixed with one or more layers parallel with the general strata—renders this part, known by its brownish-black colour and greater softness, more or less distinct from the rest of the formation. These distinct layers of jacotinga form the lode , in which the great riches of Gongo Soco arc deposited. Hociieder, Ibid , xv. p. 54. of Minas Geraes , in Brazil . 263 rather less abundant. In both cases it is difficult, if not impossible, to distinguish the auriferous band from other strata. The broader parts—connected by narrower layers— are grouped in two (shoots) masses of irregular form and unequal dimensions (PZ. II. Fig. 2). (—a.) The smaller (shoot) mass crops out at the surface west of Pengilly’s shaft; and, dipping 8°—30° towards the east,—as the strise or undulations in the iron-mica-slate also dip * *—is wrought to the 21- fathom level beyond Duval 9 s; f a range of more than two hundred and twenty fathoms. Its width seldom exceeds three inches, and is generally less than an inch. The chief ingredient is iron-glance; of granu¬ lar structure and mixed with earthy brown iron-ore in some places,—but foliated and invested with earthy black iron-ore in others where it encloses irregular lumps of earthy hydrous oxide of iron and earthy brown manganese. Buff-coloured talc is common; but friable quartz is peculiar to the granular, and pearl-white talc to the foliated, iron-ore. Within short * Kenwood, Cornwall Geol. Trans, v. p. 193; vi. p. 146 : London, Edinburgh , and Dublin Phil. Mag. } 3rd series, xxv. (1844) p. 343. Ante , pp. 207, 234, 259, Fig. 22. • f By following up the Gongo main vein, through a poor piece of ground 90 fathoms in horizontal extent, a new shoot was discovered near Duval’s shaft. * * * This has, as far as we know at present, only reached down to the 21- fathom level east of Duval’s, and it becomes very poor even there. West of that shaft it commenced to rise above the 14-fathom level, and continued rising in a westerly direction. * * * The extent of this shoot measured at right angles to its line of dip is from 12 to 18 fathoms. von Helmreichen, Harris, Collins, Blamey, & Pengilly, Reports of the Imperial Brazilian Mining Association , xxx, (1840) p. 83. 264 W. J. Henwood, on the Gold-Mines distances, however, differences, of structure and com¬ position, are frequent. A vein, unseen on the south, springs from the northern (wall) side of the auriferous (Jacotinga) deposit; and—parallel to one series of joints* in the iron-formation—bears 2°—5° S. of E. & N. of W. It is usually less than an inch, but never more than two inches, wide. Iron-glance, buff-coloured talc, earthy brown iron-ore, and manganese are its ordinary con¬ stituents, but here and there these are mixed with other substances.f (— b.) The larger ( shoot ) mass appears at the surface on the same meridian at which the smaller—separated from it by a body of inferior ore—dies out in the 21-fathom level east of Duval's;% and—accommo¬ dating itself (so to speak) to the ridges, furrows, and flexures, which, in the (walls') rocks on both sides,§ dip 10°—28° east ||—extends to the sixty-two near Vesey’s shaft,a distance of more than two hundred and fifty fathoms. Its thickness is sometimes no greater than that of gold-leaf, but never exceeds six inches. In this, as well as in the smaller, shoot the principal constituent is iron-glance; of which the granular variety—mixed now and then with earthy * Ante, p. 250. f von Helmreichen, Harris, Collins, Blarney, and Pengilly, Reports of the Imperial Brazilian Mining Association, xxvi. p. 49; xxx. p. 83. X Ante, p. 250. § Ante, p. 259, Fig , 22. || Hocheder, Reports of the Imperial Brazilian Mining Association, xv. p, 55. von Helmreichen, Harris, Collins, Blarney, and Pengilly, Ibid, xxx. p. 81, 11 PL IV, Fig . 2. of Minas Geraes , in Brazil . 265 brown, but more frequently with earthy black, iron- ore,—is generally disposed towards the (walls) sides; whilst the lamellar kinds*—interlaminated with buff- coloured talc,—-enveloping sometimes isolated lumps, sometimes subordinate layers, of earthy manganese, irregularly mingled with earthy hydrous oxide of iron, often sprinkled with pearl-white talc, and yet more sparingly with smaller quantities of other ingredients # —usually form the middle of ordinary portions, but alternate with granular ore in wider parts, of the deposit. Near the laminated mass (horse) of quartz and iron-ore which splits the Gongo iron-formation, east of Gibson’s shaft,f every buff-coloured talcose member of the auriferous (Jacotinga) bed is thickly studded with small crystals of oxydulated iron. Still further towards the east, however, these substances form detached masses, progressively smaller and further apart; at first imbedded in, but at length replaced by, beds alternately of pale-brown earthy iron-ore and quartz.^ (3—7.) Several thin unconnected bands of (Jaco¬ tinga) iron-glance, manganese, and talc interlie the schistose iron-ore within short distances on either side * The chief ingredients of the Jacotinga are iron-mica and quartz, which en¬ close beds of manganese from a quarter of an inch to three inches in thickness, as well as strings and nests of iron-glance and talc. The manganese beds have like the adjoining rocks, a southerly inclination, as well as a general (shoot) dip towards the east. Hocheder, Reports of the Imperial Brazilian Mining Association , xv. pp. 54—55. + Ante, p. 251; Table VII. column 21. | von Helmreichen, Harris, Collins, Blarney, and Pengilly, Reports of the Imperial Brazilian Mining Association , xxx. p. 81. 266 W. J. Henwood, on the Gold-Mines of the principal (vein) bed between Walkers and Baylys shafts; # but they seldom exceed a few feet in length and depth. (3—8.) The North (vein) bed forms part of the Gongo iron-series, and—partaking its flexures—ranges from three feet to ten fathoms beneath the principal f (vein) bed; but—never cropping out at the surface— has no existence, either above the fourteen or below the forty-one fathom level,—either west of Walker's shaft or east of Bayly s. It extends,— At the 14-fm. level from Walker's shaft W. to .... Lyon's E. .. fms. about 72 ,, 21-fm. >> Macfarlane's ,, .... Lyon sj a •• ft 34 „ 27-fm. Macfarlane's „ .... Lyon's a •• ft 34 ,, 34-fm. it Lyon's „ .... Gibson's a • • ft 28 „ 41-fm. a Curtis's ,, beyond Gibson's a •• ft 21 thus forming an irregular oval, about one hundred fathoms in length and fourteen in extreme depth, which dips endlong, 8°—14° towards the east. Its thickness—never exceeding two inches, and generally less than an inch — gradually diminishes upward, downward, and at either end ; until, at length, it dis¬ appears between the rocks which elsewhere form its opposite (walls) sides. Within short distances of the Slide § crystals of oxydulated iron are imbedded in a * Several small veins (beds) of manganese and talc are included in the rock between the two principal bands of jacotinga. von Helmreichen, Harris, Collins, Blamey, &Pengilly, Reports of the Imperial Brazilian Mining Association , xxx. p. 82. t “ The North vein in the twenty-one fathom level is about ten fathoms, three “ feet, six inches, north of our principal vein; but in the fourteen fathom level, “where it discontinues its course upward, it is no more than about three feet “ six inches distant.” Jennings, Collins, Harris, Bray, & Jeffery, Ibid, xiv. p. 6G. J Duval, Ibid, xxi. p, 65. § Ante , p. 252; Table VIII, columns 3, 15. of Minas Geraes , in Brazil . 267 talcose matrix; whilst elsewhere wider parts of this band contain larger quantities of the earthy hydrous oxide of iron than those of the principal (vein) bed; in other respects the mineral characters of their paral¬ lel sections are much alike. (3-9.) The New North (vein) bed , a lower member of the Gongo iron series, is wrought— mostty some fifteen fathoms, but in some places scarcely as many feet, beyond the North (vein) bed —from the surface north of Walker’s to the thirty-four fathom level near Aveline’s shaft. It neither holds down to the seven fathom level at one end nor reaches the surface at the other; but—forming an irregular oblong about one hundred fathoms long by twelve deep—dips 17°—20° towards the east. Generally less, but never more, than an inch in width, it gradually declines, as well towards either end, as towards the bottom of the mine; until, near Walker’s shaft on the west, at Aveline’s in the east, and at the thirty-four fathom level , it—like the North (vein) bed # —at last dies away. The in¬ gredients of this band f differ but little from those of the North and principal (veins) beds on the same * Ante, p. 26, t An average sample of this jacotinga afforded — Peroxide of iron. ......... 78’0 Water . 12*0 Oxide of manganese . 1*5 Alumina ... 3 0 Talc . 5-5 Gold...a slight trace. 1000 Percivar Norton Johnson, Esq., F.ll.S., F.G.S., &c., &c., MSS. 268 W. J. Hen wood, on the Gold-Mines meridian; save that the earthy hydrous oxide of iron is, perhaps, somewhat more plentiful, and nests of pearl-white talc are larger and more numerous in it than in them. Fig. 24—sketched from nature—affords a better idea than mere verbal description can give, of the complicated mixtures and interlaminations of buff-coloured talc and iron-glance, which occur in the shallower parts of this bed. Fig. 24. gongo soco. New North (vein) bed. Transverse section. Natural size. (3—10.) Between Blarney's and Collins's shafts the Cumha formation contains several such bands || of iron- * “ We have cut a vein in the Cumba formation which has given 4* ** 5 oz. of “ very fine gold.” Lyon, Reports of the Imperial Brazilian Mining Association , vii. p. 31. “ The Cumba mine has yielded a considerable quantity of valuable ore for the “ stamps; but the produce for the washing-house has been very trifling until ** lately; but between the 26th and 30th of October, 1840, upwards of 23 lbs. of “ gold were extracted from the back of the 14-fathom level.” von Helmreichen, Harris, Collins, Blamey, & Fengilly, Ibid, xxx. p. 85. of Minas-Geraes, in Brazil . 269 glance, brown iron-ore, earthy hydrous oxide of iron, manganese, and talc; but,—seldom more than a few feet in depth and never exceeding an inch in thickness —they disappear at the fourteen-fathom level, (3—11.) On either side of both shoots in the aurifer¬ ous (vein) bed, the Gongo iron-strata assume, for some distance, a thick lamellar structure and granular tex¬ ture; but adjoining the smaller mass they are more granular,* * * § whilst beside the larger they become softer,')' than elsewhere; parallel with the former the Cumba formation also puts on a rather, though not an exactly, similar character.J These changes respectively begin and end at neighbouring—if not, indeed, at the very same—waves or ripples in the strata; which, as al¬ ready shown, everywhere dip towards the east.§ In such rocks the vein north-west of Morgan's shaft || and * Table VIII. column 3. t A shaft commenced at the surface three weeks since is now about eighteen fathoms deep. Lyon, Reports of the Imperial Brazilian Mining Association, v. p. 38. At the new adit eight men have driven sixteen fathoms in fifteen days. I have promised them a reward if they complete thirty-five fathoms in the month; and they appear sanguine of success.— Ibid, p. 41. The cross-cut at the shallow adit has been driven by three men forty-eight fathoms in eighteen working days. — Ibid, Vi. p. 20. J In the Cumba adit the ground is of so favourable a nature that we have as¬ signed the men twenty fathoms for their month’s work; and have promised them a premium of three milreis (about six shillings and nine pence), in addition to their ordinary wages, for every additional fathom they may drive. Hocheder, Ibid, xvn. p. 97. “ Below the adit, the rock, although not very wet, is exceedingly soft.” Ibid, xvin. p. 54. In the cross-cut at the twenty-one fathom level towards Cumba the ground has become so very soft that we have been compelled to abandon it. Harris, Collins, & Blamey, Ibid, xxv. p. 52. § Ante , pp. 259, 263, 264. || Ante, p. 264; Table VIII. column 6. 270 W. J. Hen wood, on the Gold-Mines the smaller shoot on the principal (vein) bed of the Gongo series,* * * § as well as several shorter and narrower layers in the Cumba formation,f have all yielded gold on the same meridian. J In somewhat similar strata, the principal ,§ North, || New Norths and other smaller (■veins )** * * §§ beds of the Gongo deposit,—all dipping east, —are likewise rich between the meridians of Walker 9 s and Curtis's shafts.^: In this part of its range, how¬ ever, the Cumba series is entirely barren.ff (3—12.) Wherever hard, crystalline, massive iron- glance touches or approaches the auriferous bands, they cease to be productive. On approaching the Slide, —which is composed of oxydulated iron and talc,—the North (vein) bed partakes its ingredients, and conforms to its smaller inclination,^ but no longer yields gold. For of every auriferous band in both series, the highly inclined * Ante, p. 263; PI. IV. Fig. 2. f Ante , p. 268; Table VIII. column 6; PI. IV. Fig. 3. $ Carne, Cornwall Geol. Trans., in. p. 78. Henwood, Ibid , v. pp. 215, 233. Ante, p. 258, Note||. § Ante, p. 264; Table VIII. columns 12, 15, 18; PI. IV. Fig. 2. || Ante, p. 266 ; Table VIII. columns 15, 18. f Ante, p. 267 ; Table VIII. columns 15, 18. ** Table VIII. columns 12, 15, 18; PI. IV. Fig. 3. ff- Hocheder, Reports of the Imperial Brazilian Mining Association , xvii. p. 83. Tregoning, Harris, Collins, & Bray, Ibid, xxi. pp. 81,105; xxii. pp. 98, 102. Harris, Bray, Collins, Blarney, & Pengilly, Ibid, xxvii. pp. 51, 56. Ante, pp. 252, 266; Table VIII. columns 3,15. §§ Near the Slide the North vein has altered its dip and nature; and hitherto it has been poor.—H ocheder, Reports of the Imperial Brazilian Mining Asso¬ ciation, xvii. p. 72. Tregoning, Harris, Jennings, & Bray, Ibid, xvm, p. 94. Table VIII. Note/. of Minas Geraes , in Brazil . 271 portions are most, whilst the flattest are least, pro¬ ductive.* * * § (3—13.) But, although a general resemblance pre¬ vails throughout the North and New North (veins) beds, —both shoots in the principal (vein) bed ,—and several smaller members of the Cumba formation,! gold abounds only in certain portions; which—diffi¬ cult as it is to describe them—are easily recognised by a practised eye.J The history of Gongo Soco,§ there¬ fore, mentions no mass (bunch) of gold discovered by mere chance; although appearances, favourable at first, have—as in the mines of other countries—sometimes led to disappointment. The richest bodies of Jacotinga are seldom more than a few feet in length and depth; but, between Pengilly's and Duval's , as well as between Walker's and Bayly's , shafts the bunches have been very numerous. Near the middle of each bed f the matrix, already described, encloses rough (nuggets) lumps, usually * From the shallow-adit to the four fathom level, the vein dips faster than usual, and has a kindly appearance: it now yields rich prills, Lyon, Reports of the Imperial Brazilian Mining Association, vi. p. 54. Throughout the mine gold is most plentiful in those parts of the vein which are nearest to the perpendicular, Jennings, Collins, Harris, Bray, & Jeffery, Ibid , xiv. p. 66. At the twenty-seven fathom level near Macfarlane's shaft the strata in the western part of the works have a very flat inclination towards the south, and appear rather unpromising * * * * Eastward however the vein has held down to the back of this level, and has been very productive. Hocheder, Ibid, xvi. p. 66. Thomas, Report on a Survey of the Mining District from Chacewater to Cam¬ borne, p. 20. Henwood, Cornwall Geol. Trans,, v. p. 231. Ante, p. 82, Note*. f Ante, pp. 263—268, + -^ uva ^ Reports of the Imperial Brazilian Mining Association, xxix. p. 23. § Ibid, r.—Lxn. QQ 272 W. J. Hen wood, on the Gold-Mines but a few ounces,* * * § ' though here and there two or three pounds,! and, in an instance or two, of still greater J weight. Some of these are isolated; others, at un¬ equal intervals, are either irregularly clustered, or united by thin laminae and reticulated threads; but all are of gold. Certain broad parts of every {vein) bed have, at times, contained two or three parallel groups § of this description; which have, now and * Lyon, Reports of the Imperial Brazilian Mining Association, iv, p. 48; vi. pp. 45, 49, 58; vm, pp. 30, 33, 39. Trebilcock, Prideaux, Hambly, & Jennings, Ibid, vm, p. 71. f Lyon, Ibid, iv. p, 20; vn. pp. 35, 56; vm. pp. 35, 54, 58. Skerrett, Ibid, xiv. p. 42. j u Of the prills, now sent as specimens, one—which still weighs more than “ twenty-one lbs.—would have been more than thirty lbs., but a great part “ crumbled off in the washing.”—S kerrett, Ibid , xiv. pp. 43, 49. “ A peculiarity observed in the bunch,” west of Morgan's shaft, “ is the lumpy u nature of the work of which it is composed, and the unusual size of its prills: “ one of these was 13 inches long, from 3J to 5 inches broad, and from £ to 1| “ inch thick, weighed when roughly washed 14 lbs. 4 oz. 15 dwts., and produced, “ after being pounded, 13 lbs. 1 oz. 19 dwts, 4 grs. of gold, in which one solid, “ pure, piece weighed 1 lb. 3 oz. 16 dwts.” Duval, Ibid, xxvn. p. 25. § Our gold has been chiefly obtained from a branch beneath the vein lately worked in the back of the thirty-four fathom level east of Lyon’s shaft. Where first seen, the branch bore nearly north and south; but within a short distance its direction changed, and it is now nearly parallel to, and about ten feet north of, the vein from which it separated. This is by no means an unusual occurrence; for branches parallel to those first worked have been frequently discovered. Harris, Jennings, & Bray, Ibid, xvm. p. 65. At the thirty-four fathom level east of Gibson's shaft, a branch about four feet south of the North vein yielded on the 18th and 19th of February, 1836,—219 lbs. 4 dwts. 12 grains of gold.— Morgan, Hickson, Tregoning, Harris, Jeffery, Bray, Jennings, & Collins, Ibid, xx. pp. 38, 39, 81, 83, 86; xxi. pp. 18, 68, 69, 123; xxx. p. 82. On the 7th of February, 1840, two men extracted in three hours 105 lbs. of gold from a vein in the north wall of the old works at the thirty-four fathom level east of Curtis's shaft.— Duval, Harris, Bray, Collins, Blamey, & Fengilly, Ibid, xxviii. pp. 37, 64; xxix. pp. 23, 37, 40, 65; xxx. p. 82. Whilst opening a second level between Curtis's and Gibson’s shafts, a side- 273 of Minas Geracs , in Brazil . then, lain within so narrow a compass, that they were wrought in the same (level) gallery.* * * * § Nuggets are common near the centres of aggregations; folice f towards their circumferences. But whilst clusters, such as these, form a striking characteristic; — smaller nuggets (prills J flakes, threads, and granules,§—slightly coherent, or—more vein was discovered; which, in May and June, 1842, yielded 303 lbs. 7 oz. 13 dwts. of gold.— Cbickitt, Ibid, xxxiit. pp. 1, 4. * “ As we have had three confused branches in the fourteen fathom end for “ some days, I suspect, as they join, we shall come to a good bunch; of which “ we have already some indications.” Lyon, Reports of the Imperial Brazilian Mining Association, vn. p. 46. " In the bottom of the twenty-seven fathom level, east and west of Lyon's “ shaft * * * we have sometimes had two, sometimes three productive veins. Jennings, Harms, Bray, & Jeffery, Ibid, xm. p. 56. “ The workings in the shallower part of the mine have only been carried on “ from two to three feet in width, because there was but one vein to follow; in “ working deeper, several veins have been met with, but they were diminishing “ in richness. The works in the back of the thirty-four fathom level are now “ from seven to eight feet in breadth, in order not to miss any vein which may “ exist, either in the foot,ox the hanging-wall, of the bed.” Hocheder, Ibid, xvn. p. 79. t The late Captain John Luke, MSS. At Taquaril near Sahara strata of schistose iron-glance, enclosing, in some places, minute, conformable bands of quartz, are divided by thin beds of buff- coloured talc; and these are interlaid by plates of gold; which—frequently several inches in length and breadth, though seldom thicker than paper,—often exhibit parallel striae, similar to those observed in the larger deposits of Morro Velho, Pitangui, Agoa Quente , and Gongo Soco, and in slickensides elsewhere. John Morgan, Esq., MSS. J We have cut a strong branch of gold in the middle adit; but—owing to the unusually wet state of the level —w'e cannot see it. The vein-stuff washed to¬ day has given nearly two pounds of gold; we have for some time had prills as large as half-almonds, we now have them of an ounce weight. Lyon, Reports of the Imperial Brazilian Mining Association, vm. p. 39. § Between the seven and fourteen fathom levels the branch has a very peculiar appearance, the gold lying in it in fine dust, but few prills occurring; decom¬ posed yellowish talc and reddish-brown manganese, forming to the breadth of a span in some places, and then again diminishing to an inch in thickness. The whole of this is rich in gold, and I saw a miner’s hatful broken underground which yielded 27 lbs. 7 oz. 14 dwts. of dust. Ibid , vm. p. 61 ; Table VIII . Note ii. A hat-cap of ordinary size heaped with coarse ore is about 0*142857 cubic foot 274 W. J. Henwood, on the Gold-Mines frequently-isolated in the surrounding matrix,-furnish the chief riches—of this formation. Grains, particles, and—sometimes—small nuggets occur in numbers gradually diminishing towards the confines of every hunch; # on both sides of large masses, however, adjoining strata are, for short distances, also thinly sprinkled with gold.j* The following extracts from accounts kept at the mine show how unequally gold is distributed, as well in the hunches , as in the formation generally. Consecutive days. Dates. Washing-house. Stamps. Totals. lbs. (Troy). lbs. (Troy). lbs. (Troy). 1828. Feb. 14th .... 9*601 — .... 9*601 X 15th.... 72*121 . — .... 72-121 16th.... 17-680 . — .... 17-680 1829. Jan. 22nd .... 9*418. — .... 9-418 § 23rd.... 67-213 . — .... 67*213 24th.... 10*590 . — .... 10*590 * In parts of the productive layers where no gold is visible by the naked eye, it exists disseminated through the jacotinga. Hocheder, Reports of the Imperial Brazilian Mining Association , xv. p. 55. Most of the gold lately obtained has been from the back of the thirty-four fathom level east of Gibson’s shaft, where the auriferous stratum is occasionally divided into several layers ; in which, although the gold is not always perceptible, the jacotinga for the stamps is richer than that from other places. Ibid, xvi. p. 60. Of late the greatest part of our produce for the washing-house has been ob¬ tained from the back of the thirty-four fathom level near Curtis’s shaft. Gold- smid’s stamps, supplied from these workings, yielded during the past month (February, 1840) about fifty-nine pounds of gold. Harris, Bray, Blamey, & Pengilly, Ibid , xxix. p. 37. f In the back of the thirty-four fathom level east of Curtis’s shaft the vein has been very rich, and the stuff on either side of it has yielded a large produce at the stamps.— Harris, Jennings, Collins, & Bray, Ibid, xv. p. 44. J Ibid, iv. p. 74; v. p. 98. § Ibid , vn. p. 117. of Minas Geraes , in Brazil . 275 Consecutive days, continued. Dates. Washing-house. Stamps. lbs. (Troy). lbs, (Troy). Totals, lbs. (Troy). 1829. Feb. 24th _ 28 916 • • • ♦ 28-916 * 25th.... 81-833' . . • • • • 81-833 J>127-853f 26th .. . 46*020 J . 6-225 • t • • 52-245 Sept. 22nd. . .. 37-680’' . . • • • • 37-680 j 23rd.... 137-000 . 9-000 • • • • 146000 24th.... 69-242 . 5-500 • • * * 74-742 25th.... 140 958 ^516-654f ...... 9-166 • • # • 150-124 26th.... 68*083 . 3-000 • • • • 71-083 28th .... 63-691- . — ♦ • • • 63-691 29th.... 13-870 • • • • 13-870 1830. Jan. 20th ... , 13714 • • • • 13714 § 21st .... 777411 . — • • • • 77741 [>140-8211| 22nd.... 63*080 J . — t t • • 63080 1831. April 14th .... 2-191 . — • • • • 2-191 IT 15th.... 18772 • • ♦ • 18772 16th .... 35-786 • • • • 35786 1832. Nov. 22nd.... 5 810 . 2-566 t • • ♦ 8-376** 23rd.... 30-951 . 6-554 • • • • 37-505 24th .... 97-840ft . 2-588 • • • • 100-428 26th.... 11-158 . 1-679 • • • • 12-837 1836. Feb. 16th .... — • • • • 1-022 XX 17th _ 23.893 ••••••»« • • • • 23-893 * Reports of the Imperial Brazilian Mining Association, vti. p. 118. t Table VIII. column 15 ; Postea, p. 279. t Reports of the Imperial Brazilian Mining Association , vm. p. 121. § Ibid, ix. p. 75. || Table VIII. column 15; Postea, p. 280. U Reports of the Imperial Brazilian Mining Association, xi. p. 91. '** Ibid, xiy. p. 117. ft Table VIII. column 18; Postea, p. 280. it Reports of the Imperial Brazilian Mining Association, xxi. p. 123. 27(5 W. J. Hen wood, on the Gold-Mines Consecutive days , continued. Dates. Washing-house . lbs. (Troy). Stamps. lbs. ( Troy), Totals, lbs. (Troy). 1836. Feb. 18th .. ..116-5831 .. • •to 116*583 19th .. [>21*9018 * .. 102-435j . — • • • • 102*435 20th .. .. 11*353.... • • • • 17*180 22nd .. .. 2 025 .... .... 2*835 ♦ • • • 4*860 1839. Jan. 7th .. .. 0-341 .... .... 1*930 • # • • 2*271 f 8th .. .. 20*302.... .... 3*772 • • » • 24*074 9th .. .. 9 786 .... .... 0*804 • • • • 10*590 10th .. .... 0*834 • * • • 0*834 1840. Feb. 6th .. .... 0*374 • • • • 0*374 X 7th .. .. 28*724 § .. .... 0-250 • • • • 28*974 8th .. .. 90-020 § .. .... 3-246 • • • « 93*266 10 th .. ,. 4062 _ .... 0 853 • • • • 4*915 ' 11th .. .. — . 0*728 Consecutive months. III* 0*728 1828. February .. .. 256*562 .. .. • « • • 256*562 || March ..... .. 40*179 .... • •It 40*179 1829. August .... .. 219*315 ... .... 37*124 • • • • 256*439 IT September.. .. 711*648 ... .... 47*410 • • • • 759*058 October .... .. 270 277 ... .... 30-550 • • • t 300*827 1836. January .... .. 4-647 ... • • • • 32-903** February ... .. 301*558 ... • • • • 344*921 March . .. 17*767 ... .... 61*224 • • » • 78*991 * Reports of the Imperial Brazilian Mining Association , xx. pp, 38, 39, 81, 83; xxi. pp. 60, 69, 73, 123; Table VIII. column 21; Postea, p. 280. t Reports of the Imperial Brazilian Mining Association, xxvii. p. 66. t Ibid, xxix. p. 65. § Ibid , xxix. pp. 23, 65; Table VIII . column 18; Postea, p. 280. || Reports of the Imperial Brazilian Mining Association, iv. p. 74; v. p. 98; Table IX. columns 11—13. ^ Reports of the Imperial Brazilian Mining Association, vm. p. 121; Table IX, columns 29—37. ** Reports of the Imperial Brazilian Mining Association, xxi. p. 123 ; xxvn. p. 66. 277 of Minas-Geraes , m Brazil. Consecutive months , continued. Dates. Washing-house , Stamps. Totals. lbs. (Troy). lbs. (Troy). lbs. (Troy). 1840. January.. . ... 5*355.... ... 46*184 ... . 51*539 * February. . ... 191*231 .... ... 76*114f ... . 267*345 March .... ... 14*424 .... ... 44*769 ... . 59*193 Consecutive years 4 1827 ... . 2,010*011 .... 2,010*011 8 ...... . 1,062-200 .... 1,062*200 9 .. . 3,807*089 _ .. 383*884 .... 4,190*973 1830 . . 2,804*558 .... .. 235*957 .... 3,040*515 1 . . 2,434*414 .... .. 597*463 .... 3,031*887 2 . . 2,756*249 .... ..1,445*977, .. 4,202*226 3 . . 1,790*534.... ..1,197*922 .... 2,988*456 4 .. . 934*348.... .. 719*252 .... 1,653*600 (3—14.) From 1826 to 1856 the Imperial Brazilian Mining Association obtained §— in clusters, nuggets , and other - ) coarse gold; treated by hand £23,381*251 lbs.|| or 0 677 of the entire produce; at the washing-house .... in smaller grains and particles extracted from the jacotinga by stamping .. Total.. 34,528*098 lbs4 Rather more than two thirds of the gold occurred, therefore, in masses, plates, and threads; whilst some¬ what less than one-third was disseminated, in grains and particles, through the adjoining matrix. 111,146* * * § 847 „ 0*323 * Reports of the Imperial Brazilian Mining Association f xxvii, p. 66; xxix. p. 65. t Inferior ore is seldom or never stamped or washed the day it is broken in the mine. Postea , p. 276, Note*, t Table IX. columns 44—46. § Reports of the Imperial Brazilian Mining Association, I. — lxil || Table IX. column 44, Note. I ^ >> v 45, ,, m. 278 W. J. Henwood, on the Gold-Mines Numbers of prills and quantities of rich Jacotinga, however, were stolen by the workmen ; # who—some¬ what insufficiently superintended, f—for several years, brought to the surface in their hat-caps , J the gold they had broken in the mine. The positions and relations of the several hunches are set forth in Table VIII.; the proportions of nuggets and other rough gold they afford, are shown in the following columns :— * One of our miners, who was a few days since detected whilst washing a large quantity of gold, in a most sequestered place about four miles from the mine, has been handed over to the authorities. * * * On searching the place a large canister of rich unwashed ore was traced out by scraps of paper and old rags, in various stages of decay, denoting the length of time this nefarious traffic must have been carried on. Skereett, Reports of the Imperial Brazilian Mining Association , xi. p. 27. Our stamps have been robbed but four times in the last two years. * * * The infamous gang, who found their way into your service, formerly contrived to plunder them frequently.— Ibid, xm. p. 30. The last remittance includes nearly a pound of gold seized near the robbers’ cave. It has been returned by the authorities.— Ibid, xiv. p. 49. t “ Both captains and miners were so anxious to tear out the gold, that the “ 14-fathom level was in an instant filled with men; and such was the eagerness “ of the crowd, that it was utterly impossible for all to squeeze into the end; “ some of them in consequence amused themselves, by way of recreation, in “ taking out good work from the 7 fathom level.”— Lyon, Ibid, vi. p. 58. % “ On my return I found * * * one of the miners with such a hat of pro- “ duce ! from the end of the 14 fathom level.” Ibid , vi. p. 58; vn. p. 27; vm. pp. 34, 61. “ To bring up four or five hats full of ore occupied the miner an hour and a “ half, which might have been spent in labour * * * I have therefore provided “ leather-lined baskets five or six times the size of a hat and secured with pad- “ locks. These can be drawn up winzes and shafts without loss, whilst the “ miner continues his work.” —Skeheett, Ibid, ix. pp, 26, 28. 11 Hats shall no longer be used * * * although the miners assign as a reason “ for still bringing one occasionally, their desire to show it themselves when “ good.”— Ibid, xi. p. 28. “ The ore which was formerly left in hats when brought up is now deposited “ in a large double-locked chest.”— Ibid, xm. p. 29. of Minas Gera'es, in Brazil. 270 ++ ++ -d- ++ ++ •M* Oi 00 OS rH QO to CO CM CS pH OO OJ co pH to to 0 os O CO 01 0 CM 00 T—C CD 0 0 0 CM CM c* CO 0 0 O O 0 0 0 CO N CO CM ■HI OO 0 O cp O 0 O • 60 • G • A G • pH I I I O « I m rO O rP -O o pH M pH cS d> a 3 ro I I I I i I ++ CM CS CO to ■o. *o* ++++++++ ++ O rf O O O O O O i—l O O O O O O OO O O o © O O CM CO «—• » OO O M r -4 CO O I 00 to • • • O •—I •—t Tj< CO <—I -M- ++ -W- co eo *—t o *o CM CO QO N CO N CO CM X o Eh* O O tq 0»2 & B w H to H w o « w o G H Hi >» cS CD -CD • Si * CO 4 J* nO to p| i-H cJ bo M cj o » aJ c3 • • V n3 nO 4 • • O O • • • D=1 X • • +■> • • G G • • • rH • pH • • • • • • • • • • • • • • • • • • • • •N • • • rP • • • • r d x' +-> to X o G a 3 • n .3 *-• ? - • X ■ -*-» • «> 1 t3 as Q •!"* PS ^ CD w ~ ~ o ^ » . p • pH a <3 h3 CD X CD X O a o X •d Si CD d cS G cr 1 co X o cJ w nO >i «§ cd CD d O *v rl fc? ^ «3 *3 g m P • - 3 t-s « Ph a « rt o a a CD O G fe O £ >» pQ n3 CD -d ^ CS 1 c3 d S H W * * o I HO « .a a ◄ G o N> o I a o nd o o c3 5-» H-> H I'* t>* ^ o 'n o a ** CO H ^ I'i Is ts H N t» st< rH • • £ £ A «N p. r> JSO 5*s CO £ § G^l CD g £ g CD ra pq o» 1 e CS is Cl cs 8 «^H o p4 Co O HO co •t •§ «o 8 o >> 280 W. J. Henwood, on the Gold-Mines T 3 o o o *4 Pk 2 o O 1 £ *9 CJ O O *4 to o 4 - 4 * CO &= to 6 = 0 co Ci 0 00 CO O O CO to 0 0 CO Ci r 4 CO ■rt< co CO CO CO (N cr> O CO to tH 0 O O 0 O 0 0

?h o W w d CD M • H •P d CD Q P3 H m d o w co d 2 Cj o 2 •£ . o P-< <1 P-t o ++ 44 - ++ -? == — tp EF -+l r—« r-H O 0 0 CO 10 (M ■aH -cH 0 0 CO 0 00 JP CO

0 rH • • 6 H CO CNI • • V"H •\ *—H days days • • • • • • • • * • • • cj 03 * • '• • tx liours • « • • ai >> d rtf • • • • • • • • • • • • 0 0 fc 3 Tj (u t*! T—{ • r-H d “ •S d d~ o • « • e-t „ O S3 O -g to 2 cS -2 13 O A 0 *> CM CO oo CD o M Xi o £ • f4 • • CD a & rU Ci r-H • • : -s ,d •* •s : fn • ^ +3 a CO • S3 »>• 0 $ r-H • cJ X> • rO * • • d 0 IH s -a C\ •> O t-H CO ■aH CO ; -jh CO CO CO 1 °° r—t H H • r— * • • CD • • • • 2 • • O • P & * Zfl 4-3 U2 d 2 rQ 0 O CD 4-3 *—1 4-3 0 c3 fH 50 O c3 4-3 • 1-4 4-3 O oS ■j-j w o +■> o 52 ; •x £ !S o A tO d £ T = ^ 05 «> Cl 2. _ O. - * * m W H O 13 cd CJ «s N • «o W J 4 -i< 4 rH I-- 4 4 4 rH rH 4 rH rH § •4 r-H rH i-H s o >5 ►4 *«9 ^ *W t\ CO 40 a « ^ co •«*> Cj W W d 2 5 •» pH *« A «\ O o I •» •% nS ^ *0 3 ifc -f- ++ <0> The eastern are the most deeply seated bunches. of Minas Geraes, in Brazil . 281 From Jacotinga in which scarcely a particle could be seen by the unaided eye, the undermentioned pro¬ portions* of gold-dust were obtained at the Stamps. Date. 1832. Locality. Beds Cveins) and bunches from various levels in different parts of the mine ..... Proportion of gold extracted. 0-00001234f 1833. 1834. 1836. 1844. 1845. 1850. 1851. 48-fathom level near Veseifs shaft 0*00002051| 0*Q0000557§ 0 00000408[| 0* § 00000105 0-00000088 0-00000076TI 0-00000044** 0-00000042 ft The bunches , of which the broader and more highly inclined central parts give from ( 0*302585 to 0*521123) one-third to one-half their weight of metal, gradually diminish in width, inclination, and quality, towards their circumferences; and, at length, merge in the still thinner, flatter, and less productive por¬ tions of the {veins') beds, where two million three hundred thousand of matrix yield (0*0000004211 to 0*00000044**) a unit of gold. The poorest ores, how- * Table VIII. columns 15, 21; Table IX. column 7. t Skerrett, Reports of the Imperial Brazilian Mining Association, xm. p. 36. X Hocheder, Ibid , xv. p. 64. § Ibid, xvii. pp. 72—122, 143—148; xviii, pp. 41—57, 111—113. || F. X. Hocheder, Ibid, xxn. p. 74. H Hitchens, Ibid, l. p. 3, ** Ibid, li. p. 4; lii. pp. 7, 10. tt Tregoning, Harris, Bray, & Collins, Ibid, xxii.p. 120. If Lyon, Ibid, vm, pp, 34, 61; Table VIII, column 12; Ante, p. 276. 282 W. J. Hen wood, on the Gold-Mines ever, are wrought only whilst they afford traces of those rich hunches , which are peculiar to the Jacotinga. For ores of qualities so unlike, experience dictates the different modes of treatment.* (3—15.) The Cumba formation contains several short, narrow (veins) beds; which afforded small hunches of gold between Blarney's and Collins's shafts at the fourteen fathom level, but yielded mere scattered particles at greater depths, f The Gongo formation includes the Principal, North , New North , and several smaller, (veins) beds, already described. The New North (vein) bed crops out at the surface north of Walker's shaft; and—dipping endlong to¬ wards the east—disappears at the thirty-four fathom level near Aveline' s.\ The North (vein) bed has no existence above the fourteen;—from the neighbourhood of Walker's shaft at that level, however, it declines in like manner to the forty-one east of Gibson's; and there dies.§ The principal (vein) bed contains two large auriferous (shoots) masses; connected, near the middle of the mine, by a barely perceptible rib of inferior ore.|| The smaller or western shoot was successfully wrought from its outcrop on the mountain-side west of Pengilly's * Hocheder, Reports of the Imperial Brazilian Mining Association, xv. p. 74* Henwood, Proceedings of the Royal Geological Society of Cornwall, 1848. Table IX. Note l . f Ante, p. 268; Table VIII, column 6; PI. IV. Fig 3. t „ p. 267; „ columns 13—18. ^ „ p.266 ; „ „ 13—21. || „ p.264; „ „ 7—9; PI. IV. Fig. 2. of Minas-Geraes, in Brazil . 283 shaft, to the fourteen fathom level east of Duval’s; towards the twenty-one, however, it became small, flat, poor, and unkindly.* * * § The larger or eastern shoot f was rich, beyond com¬ parison, from the surface J to a depth of twenty-five fathoms; but thence to about thirty it declined. At the thirty-four fathom level, however, it was once more very productive; and about the forty-one large hunches were still frequent. Towards the forty-eight these were both smaller and less numerous; whilst at, and some¬ what below, the fifty-five, thin plates and dendritic flakes were obtained. From the sixty-two downward small isolated bits occurred at distant intervals; and at the seventy the Jacotinga —already dwindled to a narrow seam—afforded but a few widely-scattered par¬ ticles of gold.§ Notwithstanding the ores were so soft || that the hack of one (gallery) level was in some measure exhausted, before the shaft had reached another; the upper (14, * Ante, p. 263 ; Table VIII . columns 4—9; PI. IV. Fig. 2. t ,, p.264; ,, ,, 10 21; ,, • $ A tradition still lingers in the neighbourhood that this deposit was found during examinations prompted by the discovery of a solid water-worn mass of gold, which weighed thirteen pounds, embedded in gravel, at the confluence of the Gongo Soco and Socorro waters, near Taboleiro. The Imperial Brazilian Mining Association extracted from Gongo Soco during the first day they worked.. 0*589lbs. of gold; » week „ .;. 4*896 „ „ „ month „ . 83-652 „ „ » year „ . 672-670 „ „ Reports, i. pp, 113, 115, 124, 125; ii. pp. 69—77; hi. pp.69—71. § Ante, pp. 264, 280, 281. Tables, VIII. columns 10—21; IX. columns 2 — 46. PI. IV. Fig. 2. || Ante , p. 269. H “ As soon as the shaft is sunk a sufficient depth * * * a level is commenced, 284 W. J. Hen wood, on the Gold-Mines £ 2\,21 , and 34 fathom) levels were not entirely gleaned when the mine had attained (the 70) its greatest depth. Of the quantities obtained from the several {veins) beds, at different levels , in the same times, no accounts remain. As, therefore, our only available data assign to the deeper parts an undue value,* * * * § we have no means of correction : the following attempt to ascertain the relative proportions in which gold occurs at various depths in this formation, must be regarded as but a rough approximation. The auriferous Jacotinga was wrought, solely by European miners, with the pick alone, t Depth. X fms. 7 to 21 .. 21 „ 41 .. 41 „ 55. . Average annual quantity of, extracted by each European, lbs. (Troy).§ .... 20*871 .... Gold, _A- 19-496 _ 9*400 .... Proportion of. . 1 - . 0-790 . 0-450 As little gold was found below the fifty-five fathom level , it is useless to extend this enquiry. “ which proceeds both eastward and westward on the lode. * * * As the work- “ man goes forward, another is employed to stope or dig down the ore above the level , and as he makes progress, a third follows him in another stope; * * * meantime the shaft continues to be sunk, and becomes deep enough for other levels before the ore above the first is exhausted.” Carne, Cornwall Geol. Trans, hi. p. 70. * The richest btmches in the western shoot were obtained at the seven fathom level near Morgan’s and Duval’s shafts, whilst Vescy’s was being sunk below the forty-eight.— Table IX. columns 6, 9; Ante, p. 279. f Throughout Gongo the wettest, softest, and most treacherous part of the formation accompanies the gold. Lyon, Reports of the Imperial Brazilian Mining Association, VIII. p. 27. X Table IX. column 2. § ,, columns 3, 46, of Minas Geraes , in Brazil, 285 From an early part of the last century* * * § it has been believed, by Brazilian miners, that the shallower were the richer parts of their gold-formation ; f an opinion which deeper and more extended working, as well under German as under English direction, has not contravened.^: (3—16.) Touching the quality of the gold found at different depths,§—our information || relates only to that obtained from 1833 to 1844 between the forty-one and the seventy ; but to the produce of these and other levels , at earlier and later periods, it has—unfortunately —no reference. Depths. fms. 41 to 48. 48 „ 70. Quality (toca) of Gold. Actual. Comparative. carats. grains. 21 0*448 _ 1 • • • • * 1 20 1*774 .... _ 0*968 The finer gold, therefore, appears in the upper parts of Gongo Soco ; but in the lower of Morro Velho\ Whether the ores were wrought between the forty- one and forty-eight, or the forty-eight and seventy, they were mixed, during reduction, with much the same proportions of those broken at the same time in the shallower levels** But whether the larger * Von Eschwege, Pluto Brasiliensis , pp. 280—284. f Southey, History of Brazil , hi. pp. 56, 826. Walsh, Notices of Brazil , n. p. 130. t Ante, pp. 179, 201—203, 230—235, 241, 284. § Table IX, column 47. || Percival Norton Johnson, Esq,, E.R.S., F.G.S., &c. MSS. U Ante, p. 205. ** Ante , p. 283, *286 W. J. Kenwood, on the Gold-Mines (nuggets) lumps differ, in (toca) quality, from the smaller grains of gold, scattered through the adjoining matrix, is unknown. (3—17.) From gold extracted at different depths, and ( dressed) washed at the mine, the undermentioned proportions of other scarce metals were afterwards separated.* * * § Proportions of Depths. fms. Unrefined Gold. Silver. Platina. Palladium. Copper.f 41.. 1- 0*058814 0*001276 0*038929 0*019444 00 • • I* 0*054759 0*000711 0*041974 — X 55.. 1* 0*047614 0*000407 0*042709 —t 62.. 1* 0*044884 — 0*048054 0*037413 Means. 1- 0*052991 0*000811 0*042100 0*025374 From the forty-one fathom level downward, therefore, the proportion of Silver .... diminished;— „ Platina^ .. ,, , and ultimately disappeared;— but „ Palladium. increased;—and so did - ,, Copper. (4.) In several parts of the mine cross-veins , from one-eighth to, perhaps, three-quarters of an inch wide, bear a few degrees on either side of the meridian. Their range—whether horizontal or vertical—rarely exceeds a fathom; whilst towards their circumferences they * Reports of the Imperial Brazilian Mining Association , xvi—xxxi., Financial Statements. Table IX, columns 47—50. f Percival Norton Johnson, Esq., F.R.S., F.G.S., &c., MSS. t Copper—less valuable—was taken less care of than the rarer metals. § Several tons of Australian tin-ore,—previously freed from all trace of gold by amalgamation,—yielded, on repeated analysis, small proportions of platina. John Michell, Esq., of Calenick, MSS. of Minas-Geraes, in Brazil . 287 dwindle,*—merge, at times, in congenial quartzose bands of the Itabirite f {Fig. 25 ),—and soon disappear. Some cross-veins merely sever, whilst others dislocate, the strata. Productive portions of the Principal (vein) bed , at the seven fathom level near Williams s shaft, J and within the horse at the forty-one east of Gibson 9 s ,§ are simply intersected; but, at an intermediate spot near Lyons shaft,|| several thin bands are displaced {Fig. 25). Fig. 25. gongo soco. Dislocated strata near Lyon's shaft. Longitudinal section. Scale—one-fourth. The displacements—seldom more than a quarter of an inch in extent—are largest near the middle of the cross-veins , and diminish gradually towards their ex¬ tremities, where the strata maintain an undisturbed continuity. In all cases, however, those portions of rock which form the (hanging-walls) upper sides, occupy higher relative positions than their counterparts in the (foot-walls) lower sides of the cross-veins.^ * Henwood, Cornwall Geol. Trans, v. p. 381; Ante, p. 226. t Ante, p. 248. t Table vm. column 12. * >• „ 21 . » „ 15. U Ante, p. 226, Note f. N S S 288 W. J. Henwood, on the Gold-Mines These—like the cross-veins at Agoa Quente # —- consist chiefly of quartz; sometimes mixed with iron- ore, but never with gold. The mine—laid open by shafts, levels , and winzes ,f —was drained by (drawing J and plunger-lifts^) lifting and forcing pumps; of which the columns were iron- bound wooden pipes made on the spot; but—as cast- iron and brass were not manufactured in the Province, and the roads were unsuited to wheeled carriages— the working-barrels,^ clack-seatplunger-cases ;§ stuffing-boxes, and glans § were imported from England in pieces of about (Jive arrobas) one hundred and sixty pounds each,|| and taken from Rio de Janeiro to the mines on mules. Gudgeons, cranks, strapping- * Ante, p. 248. f Carne, Cornwall Geol. Trans., hi. p. 70. Taylor, Phil. Mag. § Annals, vi. p. 285. Henwood, Quarterly Mining Review, i. (1830) p. 405; Cornwall Geol. Tj •ans. v. PI. I. Fig. 9 1 r> Fig. 2. 3juh , Practical Geology, p. 285, I^l. 3, 4. Penny Cyclopcedia, xv. p. 238. De la Beche, Report on the Geology of Cornwall, Devon, and West Somerset, p. 556, PI. 7, 8,9. Combes, Traits de VExploitation des Mines, n. p. 152, PI. XX. Fig. 2. Encyclopedia Britannica, 8 Edition, xv. p. 224, Fig. 3. Ante, p. 145, Note t; PI. IV. Fig. 2, 3. x Taylor, Records of Mining , i. pp. 129, 130, PI. XIII. XIV, Fig. 1. Quar¬ terly Mining Review , ii. pp. 307, 308, PI. XIII. XIV. Fig. 1. Annales des Mines , 3me S4rie, i. p. 218. Combes, Annales des Mines, 3me Serie, v. p. 610, PI. XI. Fig. 11. TraiiS del’Exploitation des Mines, hi. pp. 347—359, PI. LII1. Fig. 16. Henwood. Transactions of the Institution of Civil Engineers, n. p. 57 ; London # Edinburgh Phil. Mag. xiv. p. 488. § Carne, Cornwall Geol. Trans, in. p. 59. Taylor, Records of Mining, i. pp. 129, 134, PI. XIII. XIV. Fig. 2,— XV. Fig. 1 , 2, 3. Quarterly Mining Review, m ii. pp. 306, 312. Annales des Mines, 3me Serie, i. p. 222. Combes, Annales des Mines, 3me Serie, v. p. 609, PI. XI. Fig. 10; Traite de VExploitation des Mines, in. pp. 359—362, PI. LIV. Fig. 1. Henwood, Trans . Institution of Civil Engineers, n. p. 57; London § Edinburgh Phil, Mag. xiv. p. 488. || In one instance an English founder’s inattention to this requisite limitation, caused the extra expense of land-carriage to exceed the first-cost of his goods. of Minas Geraes , in Brazil . 289 plates, and stamp-heads, of wrought-iron, are made in the neighbourhood.* From 1st January, 1826, to 31st December, 1856, the Imperial Brazilian Mining Association Received f Capital from shareholders, at the commencement. £200,000 , subsequently .. 29,874 Sundries..... £ 226 „ Proceeds of unallotted and relinquished shares. 1,905 ,, Fees on transfer of shares . 3,812 „ Interest........ 34,404 Gold-dust sold, proceeds of. £1,118,195 „ paid Brazilian Government for Provincial Duty, value of. £288,738 „ Export Duty, „ ...... 20,141 -— 308,879 £229,874 40,347 1,427,074 £1,697,295 Paid f Purchase of Estates, Mine, Slaves ,% &c......£100,808 ,, Machinery, tools, cattle, food, &c. £451,995 Salaries and wages ... .. 432,942 ——- 884,937 Sundries ... £ 522 Loss on unallotted and relinquished shares .. 796 „ by failure of Bankers.... 1,889 - 3,207 Brazilian Government, in gold dust and in money, for Provincial Duty.. £310,777 „ „ Export „ .. 22,403 - 333,180 Expenditure at Gongo Soco . £1,322,132 Expended in other mines .... £25,649 Balance, cash on hand..... 764 -- 26,413 Profit to the shareholders.. 348,750 £1,697,295 • Ante, p. 219. t Table IX., columns 52—73. X («). Of the slaves bought, with the mine and estate of Gongo Soco by the 290 W. J. Hen wood, on the Gold-Mines The Serra , known by different names, in various Imperial Brazilian Mining Association, o-f the - Capita©' Mdr Joao Baptista Fer¬ reira de Souza Coutinho, we have no record; but, with those afterwards purchased of native traders , and children born in the mean time, they numbered in Adults bought. Children Children’s children Adults hired Years a Women e8 o H Cfl O P «o 3 3 •3 -4-a o H | eft CD *3 a Females CJ -4-» o H s yy 3 3 6 — — — 4 3 7 Bea fr ived eedom heir ) • • • • y 13 ; (5). Much to their own satisfaction—the black population occupied (the Quintal) a separate village; situate on an eminence south of the high road from Sao Joao to Caethe, about midway between the European establishment and the mine. The irregularly grouped cottages consist—like those of the Brazilian peasantry —of a wooden frame-work, wattled with (cipos) tough climbing plants and laths of (taquara) bamboo, thickly plastered with clay, and heavily thatched with (capim sape) coarse reedy grass. Those inhabited by families contain several apartments; but childless couples and single people seldom cared to have more than one room; girls of marriageable age, however, slept—under care of a Brazilian matron—in quarters specially provided for them. As the old and scattered cottages fell into decay, rows of larger, higher, and more commodious tile-roofed houses were built in their stead; but the inhabitants,—objecting to be overlooked by their neighbours, and missing the snugness of their ancient huts,—generally disliked the change. of Minas Geraes , in Brazil . 291 parts of its range from east to west, between Cocaes In the mornings and evenings those who were fond of gardening cultivated little plots of bananas, mandiocca, sweet-potatoes, sugar-cane, red pepper, cab¬ bages, and other vegetables; whilst the more industrious and respectable people also planted small (rossas) paddocks of Indian corn, (feijao) beans, and pump¬ kins. These they either sold, amongst themselves, to the European miners, and to the Company ; or used, with their surplus food, for fattening the pigs and poultry which they kept in great numbers and sold at high prices. From 1844 to 1849 the Quintal was periodically inspected, and prizes were awarded to owners of the cleanest houses, best kept gardens, and finest pigs. The sums—ranging from (one pataca) about nine pence to (two milreis) four shillings and sixpence each—it is true, were but small; yet they excited much emulation, and were received with exceeding pleasure. Water for washing and for irrigation flowed through the village from a neigh¬ bouring pond, in which the men and boys used frequently to swim ; but a beauti¬ ful spring, near the mine-gate , supplied drinking-water, and filled the children’s baths. (c) The following abstracts of accounts kept at the mine show as well the kinds of clothing, as the longest, shortest, and average intervals at which similar articles were issued. Men. Intervals (months); Articles. Longest. Shortest. Average. Cloth jackets.... 35- 17- 26* „ trousers .. 23- 14- 20* Flannel shirts .. 23- 10* 15- Duck shirts .... 70- 17* 40- „ trousers .. 70- 14. 45* Cotton shirts.... 8 - 3- 5- ,, trousers .. 8 - 3* 5* „ jackets (Mine) i 70- 35- 52- „ trousers „ 35* 23- 27* ,, shirts ,, 70- 23- 39* Caps, woollen .. 23- 17* 22- Hats, leather ... 70* 17* 52- Capes, varnished cloth . 70* 17* 47* Coverlids . 65- 17- 37* Women. Intervals (months); Articles. Longest. Shortest. Average Printed-cotton dresses.... 12* 9* 11* ,, handkerchiefs 12* 7* 10- Cloth dresses .. 45- 24- 33- „ petticoats. 19. 13- 17* „ wrappers . GO 34* 43*5 Flannel shifts .. 46* 9-3 26-6 Cotton ,, 7-5 4*7 6-3 ,, skirts .. 8- 3-5 6- TTflts*. t--- 24- Capes, varnished cloth. 102* 90* 95* Coverlids. 24* 12* to © All linen and woollen goods were imported direct from England; but every¬ thing else was of Brazilian manufacture. The orderly and neatly-dressed people made their clothing last much longer than the dissolute and careless, who were sometimes in rags. 292 292 W. J. Hen wood, on the Gold-Mines and Tijuco, rises from five to eight hundred feet above ( d .) Accounts carefully kept during long periods show the Rations of each individual to have averaged,— Fresh beef .. 2*8S lbs. (Avoirdupois) per week; Bacon (toucinho) .. 0*51 ,, ,, ,, Indian corn flour (fubh) . 6*95 „ „ „ Beans (feijad) .. 3*79 „ ,, „ Prepared mandiocca flour (farinha), on Sundays . 0*40 ,, ,, „ ; Coffee (sweetened with rapadura) .... 1*50 pint per day; Rum (restillo) per man. 0*50 gill ,, ; The beef was boiled with greens and red pepper, to which rice was occasionally added;—the beans and bacon were dressed together; and the Indian-corn flour was made into hasty-pudding (angoii) ; prepared mandiocca flour — though some¬ times eaten alone—is generally mixed with beans and bacon. On Sundays some of the women also received a glass of spirits each; but many people of both sexes abstained from intoxicating drink; receiving instead, per¬ haps rather more than, its value in money. Each person received 0*45 lb. (Avoirdupois) of soap per week; and small quantities of tobacco were occasionally distributed to those who smoked. (e.) Beside lodging, raiment, and food, every one received wages; which— regulated as well by the occupation, as by the skill and industry of the labourer, from 2 d. to Is. .... and averaged 4 d. } p er week „ (80 m‘s) „ (500 ms).... „ (160ms) 5 each. ,, 3 99 3j-E elm .... „ 1 0 tZ. ) „ (140 reis) „ (1,020 ms) .. „ (372 ms) $ n Infants received a half-penny, and children of two or three years a penny a piece, which was, of course, spent in fruit and sweets. On account of their exemplary conduct thirty-eight men and twenty-two women received their rations uncooked and their wages in money; all the others were paid in tokens, current only amongst themselves and at a (venda) shop in the village; but people of good character frequently exchanged their tokens for cash at the office. The village shopkeeper furnished, weekly, a list of his retail prices; which were always compared with, and sometimes checked by, current wholesale rates. Now and then, however his supplies were insufficient, and sometimes their quality was inferior; on such occasions the people—never slow to complain— had recourse to other shops in the neighbourhood. Except that no one was allowed to buy more than half a gill of wine or spirits per day, the slaves en¬ joyed uncontrolled disposal of their wages. The shopkeeper’s accounts showed how they were expended; viz.— on Groceries.. 0*710 Fruit and Vegetables.... 0*040 Wine and Spirits .. 0*146 Drapery . 0*105 ranged amongst women, men. { 1000 of Minas Geraes, in Brazil . 293 the adjoining country. On the north rough declivities As well to encourage habits of economy as to protect the prudent from being plundered, as sometimes they were, the Association permitted a Savings Bank to be established; where all investments bore interest at the rate of five per cent., and were repaid on demand. The depositors slowly but regularly increasing— numbered at last about a score; and their individual savings ranged, from a few shillings, to more than five pounds. On retirement of the promoter, however, the people—fearing that a knowledge of their circumstances might lead his successor, a stranger, to curtail their little privileges—withdrew their money. (/.) As the men had been trained to work underground many were handy with the shovel; but—inasmuch as skilled labour was, for the most part, performed by Europeans—the slaves were neither apt at using the pick , nor expert at (timbering) propping and securing the shafts and drifts of the mine. Several, however, were more useful as charcoal-burners, car-drivers, and muleteers, than as miners; and many, taught by English artisans—became clever masons, smiths, and carpenters. Of the boys a few were brought up as miners ; seyeral worked on the farm and in the stables; many—eager for instruction—were skilful artificers; and one— an assistant in the hospital for several years—frequently operated, and adminis¬ tered simples, with great success. The women filled and drove the ore-carts, assisted at the Stamps, reaped grass, washed, and cooked, by turns. A few, of the handiest and most trustworthy, cleaned the gold. Those who had unweaned children were employed on sheltered work, which suffered no prejudice from occasional interruption; The older girls worked, generally, with the women; whilst the younger— superintended by a Brazilian matron—cleaned, spun, and wove cotton, and made and mended the clothing. The children either watched and assisted the girls at their labour, or amused themselves in an adjoining playground. The aged and feeble of both sexes cultivated a spacious garden, whence the public kitchen was supplied; whilst a few, altogether past work, either waited on the cooks, or betook themselves to the hospital. Freemen and slaves, whatever their occupations, had the same periods of labour; viz.— Miners.... 8 hours per day; Stamps-men and toAim-drivers... 12 ,, „ Artificers, women, and all others at the surface, from 7 a.m. to 5 p.m. 10 ,, „ ,r except on Saturdays, when they left work at 2 p.m. 3 For breakfast and dinner intervals of half an hour each were allowed. In the evenings young people danced in the open air to their own songs; their elders either looked on and smoked, attended to their household duties, or worked in their (rossasj fields and gardens; but at eight o’clock the village (venda) shop was shut, and a bell summoned all to their homes, (g.) As so many of the people had grown up before they were kidnapped in Africa, and the rest were their children, it is scarcely surprising that the laws and usages which regulate civilized life were frequently transgressed. The 294 W. J. Henwood, on the Gold-Mines t alternate with steep escarpments; but towards the offences, of course, differed in degree; but, unfortunately, some required chas¬ tisement. This, however, was never inflicted until guilt had been clearly proved, not only by confronting the accused with his accuser, but by the testimony of other persons, summoned on both sides, who were examined before the Chief Commissioner, one — at least—of his clerks, and a Brazilian (Juiz de PazJ magistrate. A record of convictions from 1836 to 1843, shows the annual average to have been.— Men. Women. Attempts to murder... 02 .... — Fire-raising . 0‘3 .... OT Housebreaking. 05 .... OT Theft. 15-5 .... 2-7 Drunkenness. 35‘0 ...» 103 Rioting . 5-0 .... 4*0 Adultery .. . . 8T .... 9*4 a Assaults. 100 .... 5' 3 Disobedience, and neglect of labour. 17’0 .... 5*0 Sundry smaller offences . 20*0 .... 180 111*66 54-96 Attempts to murder, fire-raising, and house-breaking, were generally punished by flogging;—theft, drunkenness, rioting, and adultery, by ferula;—assaults, pilfering, and neglect of labour, by imprisonment; and smaller offences, by trifling fines: aggravating and extenuating circumstances, however, were always taken into account. The punishments inflicted, during the same period, averaged annually— Flogging. Ferula. Imprisonments. Fines Totals. Men .... 1* ... .43- . Wom en,. <— ... ... 31* . .. 8* 63-6 1 * ... ... 72- . The floggings.. ranged from 10 to 36 lashes; ,, ferula . yy 2 „ 12 blows; „ imprisonments .. yy 1 „ 7 nights; but for aggravated crimes .. )> 7 »> 28 „ ; ,, fines. *4 a penny to nine pence. (40 reis) „ (320 rm) The surgeon was present at floggings only; the Magistrate and the Com¬ missioner witnessed every punishment. The first two or three months after a flogging passed almost without crime ; by degrees, however, offences became greater and more frequent; until—in per¬ haps twelve or eighteen months—some enormity compelled an unwilling recourse to the lash. a With Europeans and Brazilians, as well as with their own countrymen. & Fine and imprisonment were sometimes inflicted for the same crime. of Minas Geraes, in Brazil. 295 south gentle slopes, deeply scored by narrow glens, The following columns—compiled from accounts already mentioned—show that the people, generally, transgressed but seldom; whilst the repeated offences of a few hardened delinquents made up the mass of crime. Proportion of the entire Persons punished. population: Men. Women. More than thirteen times each ..... 0*038 .. 0-003 „ six ,, , but less than thirteen .. 0-088 .. 0-046 „ three „ , „ six . 0-166 .. 0*062 Thrice ... 0*093 .. 0-027 Twice.. ..... 0*060 .. 0*101 . Once ... 0*081 .. 0*096 0-526 0-335 Persons never punished . 0 062 .. 0*077 0*588 0*412 * " — " «y« - • • J 1 * (A.) Two or three hundred yards east of the village a spacious hospital- bounded on three sides by an airy court-yard, and on the fourth by a beautiful garden—afforded, in several large and well-ventilated wards, separate, though similar, accommodation for patients of all classes. The English surgeon, who superintended it, was aided in his professional labours by an experienced, keen-witted, creole (/); and in housekeeping, by a resident Brazilian matron, to whom, also, the cooks, nurses, and other attendants were subject. Servants of the Company, in any stage of disease, were received during the day; but those only who needed immediate treatment were admitted at night. The in-patients, — who ranged from eight to nineteen and averaged above fifteen,—were allowed 4*45 lbs. of fresh meat per week each, beside the ordinary rations of meal, bacon, beans, mandiocca flour, rice, and coffee (d); but, at the Surgeon’s discretion, fowls, eggs, bread, butter, tea, milk, arrowroot, wine, &c,, were partially, or altogether, substituted. (*.) At an early period of the Company’s existence a church was built, and a paid, resident, chaplain was appointed. On ordinary week-days Mass was rather slightly attended; but on Sundays and high festivals crowded congregations of slaves, indiscriminately mixed with free labourers, and the families of neighbouring farmers, not only filled the con¬ secrated place, but knelt, outside it, on the ground. Habitually, also, many confessed during Lent, and received the Holy Eucharist at Easter, O•) In 1846 the chaplain, who was also the village schoolmaster, readily under¬ took to teach the children of the Company’s people; and great pleasure, but no surprise, was felt, throughout the establishment, at finding their proficiency, in reading, writing, and arithmetic, fully equalled that of their free schoolfellows. TT 296 W. J. Henwood, on the Gold-Mines impress the scenery with a character singularly di¬ versified and romantic. Great part of this tract is covered with an evergreen forest, which, in season, glows with purple blossoms; and a luxuriant undergrowth is intertwined with climb¬ ing plants, of many kinds, which also bear flowers of rare beauty. Immediately south of the Serra broad undulating pastures (campos) extend to the river of Socorro. The flora an & fauna of Gongo Soco and its depen¬ dencies are very rich; but to them our enquiry does not extend. About half-a-mile east of the mine, several pleasant villas and many neat cottages-inhabited by the English officers and workmen -were irregularly clustered round a picturesque little church ; the spire of which—rising above a grove of palms and other evergreens—is still a To an experiment of so novel, and—as they thought—so questionable a charac¬ ter, many native slave-owners offered violent opposition : not that they objected to intercourse between young people of different conditions, for this prevailed everywhere; but because they believed education incompatible with slavery. It was soon evident, however, that instruction had not unfitted the people for labour, and that the aptest scholars were often the best and most orderly workmen. But in less than four years every measure which experience had devised (Lyon, Skerrett, Duval, Morgan, Crickitt, & Henwood, Reports of the Imperial Brazilian Mining Association , vm. p. 15 ; xv. p. 8; xvn. pp. 17, 42; xxii. p. 23; xxv. p. 18; xxvm.p. 19; xxx. pp. 39, 107—110; xxxm.p.2; xxxviii. p. 5; XL. p. 13; xli. p. 11; xliii. p. 8 ; xlv. p. 13.), for improving the physical and moral condition of the slaves, was abolished without enquiry or scruple by parties newly employed to superintend the mines. In 1857 the estates and people were sold. This account of the manner in which slaves were treated at Gongo Soco, is not offered as an apology for slavery. of Minas Geraes , in Brazil . 297 characteristic object in the landscape.* The pretty pleasure-grounds and trim gardens, — wherein fruit- trees were interspersed with flowering shrubs, and European with tropical vegetables,—the busy shop, the well-attended school, and—above all—the clean, well dressed, and respectable population; gave the beautiful little village an air of life, order, and comfort, of which the Province afforded no other example.* (VI.) (a.) The soft talcose iron-slate already de¬ scribed^ is succeeded by a foliated rock, which— conforming to the strata beneath £—dips towards the south. The lower portions—composed chiefly of reddish- brown talc largely mixed with granular quartz—are, at intervals, conformably interlaid by short, thin, lenticular masses of iron-glance and hydrous iron-ore,§ which have been carefully examined, but without success. In the upper and more quartzose part of the series, a broad band of crystalline magnesian limestone || * “ The situation of Gongo Soco adds much to its beauty, being a narrow valley, “ bounded on the north by the high wooded Serra, that runs westward from “ Cocaes, and by a lower undulating grassy elevation on the south; with the “ exception of the large house occupied by the Chief Commissioner, the others “—in which the officers, and European miners reside—are all of one story, u arranged in streets, isolated, and in the English cottage style, adorned in front “ with flower-beds, and not unfrequently with palms and other tropical trees. “ Near the centre of the village, stands a small but elegant church, for the use “ Brazilian workmen and slaves, employed by the Company.” Gardner, Travels in Brazil , p. 491. t Ante , p. 257, i Ibid , pp. 178, 183, 248, 259. $ Tregoning, Harris, Collins, Bray, Blarney, and Pengilly, Reports of the Imperial Brazilian Mining Association, xx. p. 71; xxi. pp. 78,93; xxn. pp. 114, 118; xxiv. pp. 53, 56; xxv. p. 69. || “ Very variable quantities of the accompanying rock are interposed amongst 298 W. J. Henwood, on the Gold-Mines (Dolomite), — the only one of the kind recognised within many miles.—is largely quarried and burnt for use. ( h .) Alternate layers of iron-glance and of quartz (Itabirite) form great part of the Serra da Piedade # near Caethe, and in some measure conform to its con¬ tour; but here and there the ore occurs in small lenticular beds, which—when mixed with earthy man¬ ganese and talc—sometimes afford traces of gold.f At Descoberta the iron-formation is overlaid by talcose clay-slate; thick-lamellar, soft, and of brick-red mottled with white in some places; but fissile, hard, and pale buff coloured in others. Its laminae,—like those of the rock beneath,—exhibit occasional contor¬ tions; but range, on an average, 10°-20° E. of N.— W. of S., and dip 60°-70° E. The principal joints sometimes bear a few degrees E. of N. and W. of S.; but, on the whole, they are nearly meridional. At short but unequal intervals, reniform and lenticu- lar masses of granular quartz either interlaminate the “ the calcareous portions * * * * A specimen free from admixture contained “ Carbonate of lime. 29*7 per cent. “ Carbonate of magnesia. 35*6 „ “ Silica. 0*5 „ “Alumina. 02 „ u Protoxide of iron. 3*2 „ 99-2.” Faraday, Reports of the Imperial Brazilian Mining Association, v. pp. 90, 92. * “ Dans la Serra da Piedade * * * la masse d’itabirite est puissante de plus “ de 1,000 pieds.”— von Esciiwece, Annalcs des Mines , vin. p. 419. von Spix und von Martius, Reise in Brasilien, i. p. 396; ii. pp. 422, 456. de Saint Hilaire, Voyage dans VInttrieur du Bresil , i. p. 137. Gardner, Travels in Brazil, pp. 500—502. Ante^. 169. t Henwood, Cornwall Geol. Trans., \i. p. 294. of Minas-Geraes, in Brazil. 2 99 slate, or conform to its joints; but—unlike the larger bodies at Morro Velho # — no single mass interlies both. The shallower layers and vein-like bunches sometimes touch at their edges; but even at a depth of twelve fathoms* both their sizes and numbers have already diminished. Few of them, however, exceed a fathom in length, or six inches in width; and generally, they are much smaller. The quartz is milk-white in the harder and paler slates; but it is deeply tinged with earthy brown iron-ore in the softer and darker- coloured strata.f Although no member of the talcose series is abso¬ lutely barren, the white quartz and the (Country) schistose rocks afford mere traces of gold; many small beds of (gossan) quartz and earthy iron-ore, however, are very rich.f Notwithstanding a slight admixture of tellurium, the gold is of excellent quality.f Sub-angular blocks of iron-glance, cemented by earthy brown iron-ore ( Canga\ ), overlie the talcose formation. Operations are carried on in the same rude and thriftless way as at Itabira § and Pitangui; || but the mine is wrought only at intervals, when the proprietor —a wealthy land-owner— has no field-work for his slaves. (c.) The iron-formation, which—ranging some 10° *Ante, pp. 187, 206, 207, Table VI. t Henwood, Cornwall Geol. Trans ., vi. p. 295. + Ante, pp. 216, 236, 247, 248. § Ibid , p. 218. || Ibid , p. 224. 300 W. J. Hen wood, on the Gold-Mines W. of N.—E. of S., and dipping 40°-65° E., # —has long been extensively wrought between Boa Vista and Durao f in the lower slopes of the Cara^a, is succeeded by rocks of which quartz and talc are chief ingredients. Amongst these, coarse-grained reddish-brown and pale buff coloured quartzose talc-slates-scarcely distinguish¬ able from the auriferous beds wrought in a lower part of the series at Santa Rita\ —are largely developed. Bands of fine-grained greyish-white quartz-rock, often thinly sprinkled with talc, interlie the talc-slate at un¬ equal intervals; but, after comparatively short courses, they gradually become thinner, and ultimately dis¬ appear. Higher portions of the talc-slate series, however, alternate with broad, slightly foliated beds, composed in great measure of indurated talc, mixed generally with red and brown earthy iron-ore, and less frequently with granular quartz. Near Cattas Altas some of these—mottled with pearl-white talc—afford a few small crystals of topaz.§ Particles and granules of gold are scattered through all the softer strata; but seldom in quantities sufficient to pay for extraction.|| * Ante, pp. 221—241. t In 1814, the mines of this range—wrought by 165 freemen, and 288 slaves, yielded 16,660* * * § 25 oitavas (= 160*04 lbs. Troy) of gold.— von Eschwege, Pluto Brasiliensis . Tabellarische TJebersicht aller Goldlavras jeden Districts in der Provinz Minas Geraes, iv. %Ante , p. 176. § Near the village of Catas Altas “ there are slips in some of the mountain- “ sides in which topazes are found, but rarely any of good quality.” Mawe, Travels in Brazil , p. 289. || The whole vicinity is irrigated by numerous rivulets, many of which are of Minas- Gcrocs, in Brazil. 301 These talc-slates, with their subordinate bands of quartz-rock and ferruginous talc, not only mantle the lower eastern slopes of the Cara^a, but stretch far into the (Campos) open country, from Brumadinho to Cattas Altas, and thence beyond Camargos. ( d .) At Fraga , near Bento Rodriguez, grains of quartz, nests of pearl-white talc, crystals of oxydulated iron, and particles of gold, are irregularly disseminated through a breadth of many fathoms in several adjoin¬ ing beds composed chiefly of indurated talc, deeply coloured with red and brown earthy iron-ore; which have been occasionally wrought for many years,* * but with little success.^ These somewhat imperfectly lamellar talcose rocks— maintaining a tolerable parallelism to the neighbouring mountain, and ranging from south-east to north-west, —enclose a bed of different character, which interlies them for some distance; on meeting one of their principal joints, however, it takes a meridional direc¬ tion; but on entering the quartzose talc-slate ( Ita - columite ), it dwindles from several feet to a few inches in width, and at last dies away. Quartz, either colour- “ diverted from their courses to a great distance for the purposes of gold-washing. “ In all parts, even on the tops and sides of the hills, we observed operations of “ this kind going on.”— Mawe, Travels in Brazil , p. 289. * In 1814 thirty-six slaves extracted 1684 oitavas (=16*176 Troy lbs.) of gold. von Eschwege, Pluto Brasiliensis , Tabellarische Uebersicht aller Gold- lavras jeden Districts in der Provinz Minas Geraes, v. t The proprietor, like many other Brazilian mine-owners, neither clothed his slaves well, nor paid them wages; but unwisely allowed them instead, the un¬ controlled disposal of all gold they obtained from appointed spots, by voluntary labour on Saints’-days. 302 W. J. Henwood, on the Gold-Mines # less, milk-white, or deeply tinged with earthy brown iron-ore, is the chief ingredient; but pearl-white talc is also abundant; and flakes of iron-glance, as well as crystals of oxydulated iron, are irregularly scattered through the entire body. Small quantities of the (gossan) darker-coloured quartz are, at wide intervals, richly impregnated ; and drusy cavities (vughs) in the other varieties are sometimes spangled with octahedral crystals of gold. The mine was wrought to a depth of twenty-one fathoms, but it yielded no profit. (e.) At Thesoureiro , between Marianna and Camar- gos, a broad band of imperfectly lamellar slate ranging 10°-20° W. of N. and E. of S., dips 50°-60 Q S., con¬ sists mostly of brick-red talc sparingly mottled with earthy white felspar, and differs from the adjoining rocks only inasmuch as it contains many small beds of colourless, smoky, milk-white, and brown quartz. Some of these interlie the laminae, others the joints,* and many are oblique to both. None exceed a few feet in length, by an inch or two in breadth; and generally they are even smaller. No part of the formation is, perhaps, absolutely barren; but its talcose ingredients, as well as the beds of colourless and smoky crystalline quartz they enclose, are comparatively poor; the white and brown quartz—one flecked with oxydu¬ lated iron, the other mixed with much earthy brown iron-ore—afford many small but rich hunches; so irregularly distributed, however, that the same work- t Ante, pp. 299, 301. of Minas Geraes, in Brazil. 303 (Troy-) people who extracted 17* *695 lbs. of gold, in the last six months of 1842, obtained 0*461 „ „ only in the first six months of 1843 ; * even then drusy crevices in their least productive parts were sometimes thinly studded with little crystals of gold. (/.) At Antonio Pereira the iron formation f is overlaid by a series of conformable beds several hundred fathoms in thickness; which,—ranging about south¬ east and north-west,—dipping 10°-45 Q north-east,— and by turns of massive, fissile, or thick lamellar structure,—consist, in great measure, of red or brown earthy iron-ore and aluminous clay, largely mixed and often interlaminated, however, with whitish talc, and —less frequently—with earthy black manganese, iron- glance, and quartz. Although the entire series is more or less auriferous, certain unpromising beds have been but slightly ex¬ amined ; both above and below them, however, other strata were, for some time, largely wrought J at Malta Cavallos , § Tacoara Queimada , Macacos, || Matta IV * Colonel Fernando Luiz. Machado de Magalhaes, MSS. t Ante, p. 213. + Da Gama, Edwards, Gardner, Tregoning, &Martyn, Reports of the Imperial Brazilian Mining Association, I, pp. 49-64. % Late in the last century a hunch, from which (1,800 oitavas) 17*29 Troy lbs. of gold were extracted in two hours, was discovered about (100 palmos) 12 fms. below the surface at Matta Cavallos. The workmen, however,—too eager in pursuit of their prize—unhappily neglected the sides of the shaft; which, sud¬ denly collapsing, crushed an overseer (feitor) and ten slaves, whose remains still lie buried in the ore.— Da Gama, Ibid , i. pp. 49-51. Gardner, Ibid, I. p. 56. von Spix und von Martius, Reise in Brasilien, I. p. 401. Walsh, Notices of Brazil, n. p. 210. || “ At the lavra Macacos we have sunk and driven in different places about “ thirty-six fathoms, but finding that as we sunk, the formation instead of im- u proving became worse, and its appearances more unfavourable, we after some U U 304 W. J. Henwood, on the Gold-Mines Matta , and Rumao* * in different parts of their range; some of these afforded rich bunches , f others were thinly sprinkled with gold; # but all have been long since abandoned. The auriferous beds of ferruginous talc-slate are succeeded by calcareo-siliceous rocks; J which, imme¬ diately above the (lavra) works of Matta Cavallos , form a cliff, perhaps one hundred and fifty feet high. This deposit consists generally of coarsely-foliated brownish-grey quartz-rocks, which enclose small lumps and thin veins of milk-white quartz; sometimes, how¬ ever, lime is an ingredient in the mass, and then the included portions are of calc-spar. Particles and minute flakes of gold are thinly disseminated through the white quartz; but are found in no other part of the formation. The calcareo-siliceous rocks are overlaid by a few thin, fissile beds of pale blue slate. “ consultation were of opinion that it would be a waste of time and money to “ proceed any further,” * * * . “ At the lavra Rumao we have, by aid of a hand-pump, sunk a shaft 6| fathoms ; “ and have driven north-west about 10 fathoms : different parts of the formation “ show gold, but it would in no way meet the expenses, and as we could see “ nothing to warrant further operations, we were unwilling that any more money “ should be wasted so we accordingly shut it up,” * * * . “ There are several formations in the estate, and each of them when washed “ will show a little gold, but after having examined them very minutely, and “ proved them in several places by sinking and driving where we thought there “ appeared any chance of success, we feel no hesitation in saying we believe “ they will never pay the expenses of an English Company.”—T rebilcock. & Jennings, Reports of the Imperial Brazilian Mining Association , vn. pp. 95, 96. * Ante , p. 303, Note |j. f Ibid , Note $. X “ At Antonio Pereira we found primitive limestone, and * * * dolomite, “ both granular and lamellar, in great abundance.” Caldcleugh, Travels in South America , ii. p. 263. von Spix und von Martius, Reise in Brasilien, i. p. 402. von Helmreichen, MSS. of Minas-Geraes, in Brazil . 305 ( g .) At Capao* near Ouro Preto pale-blue talcose * 44 At the topaz-mine near Capao * * * the argillaceous schistus, which 44 formed the upper stratum, appeared in a variety of stages, the greater part 44 migrating into micaceous schistus. In one part I observed two negroes poking 44 in the little soft veins, which the slips ” of rock 44 disclosed, with a piece of 44 rusty iron, probably part of an old hoop ; and on enquiring what they were 44 about, I was informed they were the miners, searching for topazes. I took 44 one of their instruments, and on using it as they did, found these veins to 44 contain a very minute micaceous substance approaching to earthy talc, also 44 some quartz, and large crystals of specular iron ore. I had the good fortune 44 to find two or three topazes, which, as they had only one pyramid each, and 44 appeared fractured, I judged to be out of their original place. * * * I fully 44 expected to meet with some having double pyramids, but to my great disap- 44 pointment, all that I found were entirely detached. From a great quantity 44 (at least a cartload) of inferior topazes, * * * I could not select one with a 44 double pyramid. They informed me that sometimes, but very rarely, topazes 44 had been found attached to quartz, but even in these instances the quartz was 44 fractured and out of its original place. The topazes which were shewn to me, 44 were very imperfect, and full of flaws. They also informed me that green 44 topazes were sometimes found, which I very much doubted. If any substance 44 of that colour, resembling topaz, did occur, it was most propably Enclose,'* Mawe, Travels in the interior of Brazil , pp. 233-4. 44 The Euclase, which is still of such rare occurrence, is met with in streams 44 in the immediate neighbourhood of this topaz work; but never either attached 44 to or embedded in the quartz.” Caldcleugh, Travels in South America, n. p. 232. “ Von dem Morro de Gravier sleight man nur wenig abwarts, um zu der scho~ 44 nen Fazenda Capao und der eine Viertelstunde weiter entfernten Fazenda Lana 44 zu kommen. Diese Gegend ist die Fundgrube der bekannten brasilianischen 44 gelben Topase. Die Grundlage des Gebirges ist auch hier der Gelenkquarz, 44 jedoch steht derselbe selten in seiner gewohnlichsten Form, dagegen ofter in 44 der, von Eschwege Eisenglimmerschiefer genannten. Ab’anderung zu Tage 44 an. Auf ihm liegen m'achtige Lager eines modificirten Glimmers, den man 44 auch erdigen Talk nennen konnte. * * * Unmittelbar hinter der Faz. Lana 44 ist ein Hiigel auf der einen Seite, im Umkreise von mehr als zwei Tagwerken 44 un bis auf eine Hohe von sechzig Fuss, durch liegen und kiinstlich herab- 44 gefiihrte Wasser so aufgeweicht, dass er einem Breie gleicht, und sich, ohne 44 sich im Einzelnen zu verschieben, immer tiefer herabsenkt. * * * Das 44 Erdreich wird mit Schaufeln in lange Haufen aufgeschuttet, und durch darii- 44 bergeleitetes Schlemmwasser in einenengen,miteinigen Holzgitternversehenen 44 Canal abgespiilt, so dass nur die festeren Theile zuriickbleiben, welche sodann 44 mit llauen und den Handen durchwuhlt, und nach Topasen durchsucht werden. 44 Diese harteren Bestandtheile der aufgelosten Formation sind die Trummer 44 eines oft ganz brocklichen weissen Quarzes, bisweilen mit losen Bergkrystallen 44 durchmengt, und werden oft von einer weissen oder braunen eisenschiissigen 44 Porzellanerde begleitet. Letztere, welche hier Massa branca nennt, ist das i 306 W. J. Henwood, on the Gold-Mines clay-slates bound the opposite sides and conformably “ sicherste Zeichen von dem Yorkommen der Topaze, die sowohl zwischen hir “ als, jedoch seltener, zwischen dem zertriimmerten nnd aufgelosten Quarze lose “ und zerstreut liegen. Den fein aufgeweichten Glimmer von gelblich-und “ to mback-brauner Farbe, den man erdigen Talk zu nennen versucht ist, bezeicb- tc nen die Arbeiter mit dem Namen der Malacacheta. In ibm findet man die “ Topaze ebenfalls, aber minder haufig als in jenen zertriimmerten Ueberresten “ von Gangen, und zwar bat man sie nicht bloss in dem aufgeweichten Theile der “ Formation, sondern, wie namentlich bei Capao , auch in dem noch festen “ bemerkt. Gemeiniglich l’auft der die Topasen enthaltende, mit Porzellanerde “ ausgefullte Quarzgang in einem Salbande von erdigem Talke, welcher sich von “ dem nabe liegenden durch Farbe und Dichtigkeit unterscheidet, und Formafao “ genannt wird. Der Quarzgang, dessen Hauptrichtung wegen der Beweglich- “ keit der ganzen Masse nicht immer ganz Dieselbe ist, bei unserer Gegenwart “ aber von Mitternacht nach Mittag lief, bat eine Machtigkeit von einem zoll “ bis zu anderthalb Fuss und dariiber, und wird von den Arbeitern sorgfaltig “ verfolgt. Nicht selten macbt ergrosse nesterformige Erweiterungen, welche “ nichts als tauben, zertriimmerten Quarz ohne Topase darstellen. Dieletzteren “ werden ausserst selten noch im Zusammenhange mit dem Quarzgesteine oder “ mit Bergkrystall gefunden; gewohnlicb sind sie auf der einen Seite abge- “ brochen ; solcbe mit krystallinischen Endflachen an beiden Seiten haben wir “ selbst in der Grube nicht auffinden konnen. * * * Die Grdsse der Steine ist “ sehr verschieden; nach der Aussage der Arbeiter sind schon faustgrosse Stiicke “ gefunden worden. Die natiirlicbe Farbe ist mannichfaltig, bald graulichbald “ w r eingelb, dann eine Mittelfarbe aus Weingelb und Fleischroth von verschie- “ denen Graden der Hohe, selten dunkelrotb. Die jenigen Steine, welche in der “ Malacacheta gefunden werden, sollen die hellsten seyn. * * * Di e Zahl “ der hier j ahrlich gefundenen Topase ist sehr betrachtlich, und diirste sich auf “ fiinfzig bis sechzig Arrobas ” (2560 to 3972 lbs. Troy ) “ belaufen, jedoch ist “ diese Summe nicht immer ganz rein und zur Yerarbeitung geeignet, veilmehr “ ist ein grosser Theil derselben von so unreiner Farbe und so voll Spriingc, “ dass er von den Besitzern weggeworfen wird. Yon der geringstein Sorte tl der zum Schnitte-tauglichen Steine wird die Octave ” (55*33 grains') “ zu “ dreihundert und zw'anzig Reis ” (about nine-pence), “ von der besten zu zwei- “ tausendReis” (four shillings and sixpence) “ verkauft. Aus gezeichnet grosse, “ schone, feurige Steine, zahlt man an Ort und Stelle mit zwanzig bis dreissig 11 Piastern. * * * Zugleich mit den Topasen kommt hier die Euklase (Sqfira) “ vor, welche erst, seitdem Mineralogen Nachfrage nach ihr gethan haben, die “ Aufmerksamkeit der Mineiros auf sich zieht. Im Allgemeinen ist diese “ Steinart selten, und zwar kommt sie haufiger in der Mine von Capao als in der “ von Latia vor.”— von Spix und von Maktius, Reise in Brasilien, I. pp. 327-9. “ Les couches talqueuses, liees au thonschiefer, ofFrent un champ plus riche “ aux mineralogistes. * * * Au milieu de parties de ces roches reduites & “ l’etat d’argile, on trouve en nids et en petites veines, dans de la lithomarge, de “ beaux cristaux jaunes de topaze dxi Bresil , de Veuclase, mineral si rare, du/er “ oligiste en grandes tables hcxagonales, accompagne de cristaux dc mica. Des of Minas-Geraes, in Brazil. 307 interlie several parts of a broad band, which—ranging nearly E. and W., and dipping 20°-30° S.,—consists in great measure of earthy talc and brown iron-ore; mottled, however, with felspar-clay, and, less frequent¬ ly, with iron-glance. Irregular masses and, either imperfect or double-pointed, crystals of quartz are, without apparent order, implanted throughout. Crystals of topaz—imbedded singly—are peculiar to no part of the formation; but are most numerous where felspar abounds. Their positions are as uncon- formable with regard to one another as they are to the natural faces, and imperfectly lamellar structure, of the surrounding ingredients; and thus dissimilar matrices sometimes enclose different parts of the same crystals. They are of every hue between dark amber and pale yellow;—from half an inch to ten inches, though on an average from two to three inches, long;—and from one-eighth of an inch to three inches, but generally about half an inch, in thickness. Their opposite ends present, sometimes planes perpendicular to the axis of the prism, sometimes dissimilar pyramids; * * more fre¬ quently, however, one extremity is plane and the other pyramidal. But, except as specimens, few are of much “ cristaux de quarz hyalin avec des topazes implantees, ou reciproquement des “ cristaux de quarz implant^s dans ceux de topaze, et du disthene , rendent ce “ gite plus interessant encore: les pays dapuis Villa Rica jusqu’ a Capao, en “ offrent les plus beaux exemples.”— yon Eschwege, Annales des Mines, vm. p. 416; Pluto Brasiliensis , pp. 385-9. Claussen, Bulletins de VAcademie Royale des Sciences de Bruxelles , vm. Ire partie, p. 326. Daubree, Annales des Mines, 4me Serie, xix. p. 704. * Phillips, Mineralogy , 3rd Edition, p. 84. Mohs, Mineralogy (English trans- lation by Haidinger), n. p. 31. Jameson, Mineralogy (Encyclopedia Britannica), p. 195, 308 W. J. Henwood, on the Gold-Mines A value; for the greater number either are flawed,— enclose crystals of iron-pyrites, iron-glance, talc, and other substances,—or exhibit minute cavities, some seemingly empty, but others partly filled with pale yellow or orange-red liquid.* The flaws seem confined to no part; but the implanted minerals and the cavities occur on certain planes parallel to the axis of the in¬ cluding topaz. Open crevices in imperfectly formed crystals sometimes contain symetrically disposed octa¬ hedrons of oxydulated iron, their facets bearing fre¬ quent impress of substances which have disappeared. The same formation yields also the euclase, but in much smaller numbers than the topaz, Cross-veins of quartz, some two or three inches wide, range nearly north and south, but do not displace the strata they intersect. An excavation, perhaps one hundred fathoms long, fifty wide, and from sixteen to twenty-five deep, has been made at Capao in pursuit of the topaz; but as a large stock of crystals has, for many years, remained unsold,')' the works are seldom resumed, except to satisfy the enquiries of visitors. At Boa Vista, in the same neighbourhood, a similar formation affords crystals of topaz in equal abundance; but there also operations have been discontinued. (VII.) Great part of the district is overlaid with dis¬ integrated matter; composed, mostly, of talc, quartz, * Brewster, Edinburgh Journal of Science , v. (1826), p. 126; Edinburgh New Phil. Journal , xxxvm. (1845) p. 386. t A tolerable collection may be made, at the rate of a few pence per specimen. of Minas-Geraes , in Brazil . 309 and earthy red iron-ore: * in which search for gold is still made here and there, but with little success. A .—Directions of the auriferous deposits extend to almost every part of the compass, Rocks. m S,«g CO O O M .\ . o c/5 4h o o • O rq o ^ o CO V. o • £ m «« o wV 1 ^ o W 0 o CO E. & W. to 30° N. of E. -S. of W. • £ o O 8 tn J ‘ oM CO 4-1 o • £ • ts 4-i o &« *5* O o CD Uranite Lower talcose and micaceous ) 1 1 1 slates . j 1 1 I 1 4 Quartz-rocks ...... — 1 — — 1 — 2 Clav-slates . 1 2 3 1 7 Lower limestone . 2 1 C Q Iron-slates (Jacotinga) . 4 4 6 2 3 o 19 Upper talcose and micaceous ) o slates . j i A l 4 Upper limestone 1 1 2 Totals . 6 10 4 12 5 4 41 Proportions . •146 •245 •097 •293 •122 •097 1 but, like the lodes of Cornwall and Devon,f they have * Claussen Bulletins de VAcadimie Royale de Bruxelles , vm. Ire partie, p. 329. + Directions of veins, in Cornwall and Devon . N. &S. to 30° W. of N_ E. of S. 300—60° W. of N.— E. of S. 60° W. of N.— E. of S. to E. & W. E. & W. to 80° N.of E.— S. of W. 80°—60° N. of E— S. of W. 60° N. of E.— S. of W. to N. & S. Metalliferous veins {lodes) Cross-veins.. j-044 •498 •136 •245 •136 •049 •500 •012 •152 •061 •032 -1 •135 1 Henwood, Cornwall Geol. Trans. } v, Tables CHI. CVI. 310 W. J. Henwood, on the Gold-Mines most frequently a nearly easterly and westerly range. The foregoing* details * * § show, however, that the auriferous deposits, as well as the rocks they interlie, maintain—whatever their mineral character—an exact parallelism with the chains of mountains in which respectively they occur. B.— Inclinations of the auriferous deposits where they interlie the planes of schistose structure—varying from 10 to 70°— average about 42° ; t „ conform to the joints.— „ 45 „ 80°— „ 65°. J The highly inclined portions are not always rich, but the flatter parts are ever poor.§ C.— Sizes or widths of the auriferous deposits. Except, perhaps, the upper limestone of Gongo Soco (VI. «),|| no considerable part of the series, above the granite of Caethe and of the Cara^a,^ is absolutely barren; but the portions which either contain gold enough to be worth extraction, or offer promise to the miner,—though here and there several fathoms**— are generally from about two to eight feet wide; the * Ante, pp. 176—304; Table X. columns 2, 4, 11. f “ Throughout Cornwall, and the west of Devon, the mean dip of the lodes “ may be about 70° from the horizon, but in this respect there is a considerable “ difference between the lodes in the eastern and western districts.” Henwood, Cornwall Geol. Trans., y. p. 247. t “ To whatever point the cross-veins may incline, their inclination from the “ horizon is on the whole considerably greater than that of the lodes , and, on an “ average, is probably little, if at all, less than 80°; although there are many “ exceptions.”— Ibid , p. 277. § Thomas, Survey of the Mining district from Chacewater to Camborne, p. 20. Henwood, Cornwall Geol. Trans., v. p. 231; Ante , pp. 82—3. || Ante, p. 298. 11 Ante , p. 174. ** Ante , pp. 189, 190, 255. Tables VI. VIII. X. of Minas Geraes, in Brazil. 311 richest layers, however, seldom exceed six inches, and are often less than an inch.* D .—Relations of the auriferous deposits to the rocks which adjoin them. (1.) Composition —( a .) The only auriferous granite in Minas Geraes consists of a yellowish felspar, white quartz, and oxydulated iron-ore; f irregularly mixed, however, with crystalline granules of gold which— alloyed with from 0*05 to 0*08 its weight of palladium,:}: and sometimes enclosing, but more frequently imbedded in the other ingredients—thus forms an integral part of the rock.§ (6.) The talcose slates which—thinly sprinkled with particles of gold—rest on unproductive granite near Caethe and in the Cara$a,|| as well as those which, in like manner, overlie the auriferous iron-ores in higher parts of the series,enclose broad bands and short, thin layers of quartz; which generally conform to the foliation, seldom follow the joints, and are still less frequently oblique to both.** These are, at unequal distances, conformably interlaid by narrow beds and small lenticular masses of the neighbouring rocks. * Ante, pp. 230—2, 262—4, 266—7, 269, Tables VIII. X. t Ante, p. 175. %Ante , p. 176. § Berger, Geol. Trans., i. p. 120. De Luc, Geological Travels, in. p. 342, Herbert, Asiatic Researches, I. p. 236. Sedgwick, Phil. Mag. PP- 177, 299, 301—2. of Minas-Geraes, in Brazil . 321 (c.) The thick-lamellar quartz-rocks of Catta Preta are interlaid by crystalline beds and floors of colourless quartz. In these, minute crevices without number are commonly filled with earthy red iron-ore; through which small quantities of gold are sometimes thinly sprinkled.* * * § ( d .) The clay-slate of Morro Velho —slightly trans¬ fused with pyrites at intervals,—yields small quantities of gold f to some distance from the large deposit of pyritous quartz, with which it unites by gradual changes of mineral character.^ But in this, as well as in the talc-slate,§ formation the riches are mostly obtained from particular beds, which —now and then of short range,|| but often of great extent,—commonly interlie the planes of cleavage,^" though certain portions conform to the joints,** and others are oblique to both.ft These, as already men¬ tioned,^ consist mostly of quartz; largely mixed, however, with earthy brown iron-ore near the surface; but with enormous masses of quartzose slate and of * 0*0000132 their weight of-gold was obtained from the beds of quartz at Catta Preta. Ante, pp. 182, 316. t From 0*00000143 to 0*00000353 its weight. Treloar, Walker, Reay, and Symons, Reports of the Saint John (Tel Rey Company , xx. p. 53; xxiv. p. 43; xxxi. pp. 45—8; Ante, pp. 186, 196. X Ante, p. 194. § Ibid, p. 319. || Ibid, p. 183, H Table X. columns 4, 11. ** Ibid, columns 7, 11, tt Ibid, columns 4, 7, 11. XX Ante, pp. 182—4, 190, 194, 202, 312, 317; Table VI. columns 5, 8, 11, 14, 17, 20, 23. 322 W. J. Henwood, on the Gold-Mines iron-pyrites, in which smaller quantities of arsenical and of copper-pyrites, and cavities lined with crystals of spathose iron, arragonite, and quartz, are enclosed at greater depths. Through the siliceous ingredients gold is mostly distributed * * * § in much the same manner as through corresponding parts of the talc-slate; f but sometimes it is determined to the crevices; J which in a few cases are as numerous as in the quartz-rocks. Through the more deeply seated pyritous portions,§ likewise, gold is (by assay) found irregularly dis¬ tributed ; || but whether these inequalities depend on differences in the sizes or in the numbers of the granules, is unknown ; for the metal is so minutely divided,^ that it is undistinguishable by the naked * Ferruginous quartz from the Camara mine yielded 0'000000744 its weight of gold. Ante, pp. 182, 247. f Ibid, p. 320, $ Ibid, p. 182. § “ At a ” gold “ mine in Orange County ”—"Virginia—“ which I visited the u contents of the vein became more and more pyritical as it descended, until, at t( a depth of one hundred and twenty feet, no more quartzose matter appeared, “ and the entire vein was composed of a finely granulated sulphuret of iron.” Featherstonhaugh, Excursion through the Slave States, ii. p. 356. || At Ouro Fino the pyrites yielded 0-0000140 its weight of gold. John George Goodair, Esq., MSS. Ante, p. 184. Monthly assays of pyritic ore at Morro Velho range from 0-0000145 to 0 0000395, and average.. 0 0000229, but selected specimens afford.... 0 0001835. Reports of the Saint John d'el Rey Company, xxvi.— xxxii. Ante, p. 197. Table Via. Treloar, Report of the Saint John d'el Rey Company, xxiv. p. 26. Ante, p. 197, NoteJ. If “ In some instances the crystalline structure of the pyrites is beautifully “ exhibited ” in the mines of Virginia, “ the incipient decomposition of the crys- “ tal showing the complex laminated structure of the interior, where bright “ laminae of native gold are seen leaning against the parietes, with transparent “ crystals of sulphur formed from the decomposition of the sulphuret.” Featherstonhaugh, Excursion through the Slave States, n. p. 355. of Minas-Geraes, in Brazil . 323 eye.* * * § In the matrix most congenial to gold at Morro Velho , however, pyrites is leavened with quartz, f The North Branch £ and great part of the principal deposit^ conform to the cleavage || of the adjoining slate: in both the larger masses** * * §§ (shoots) of ore —coinciding with its undulations jj~ (ripples) —dip towards the east; and both—like the beds of Jacotinga at Agoa Quente and Gongo Soco §§—are produc¬ tive on the same meridian. Smaller portions of the principal formation, however, follow the joints; ||| and in such—as in the iron-formation at Pitangui and Agoa Quente ***—the richer and the poorer parts respectively, are bounded by the edges of widely dis¬ similar strata. (e.) The calcareo-siliceous portion of the Itabirite\\ j' —wrought only at Cocdes and Gongo Soco in the same * Henwood, Cornwall Geol. Trans,, vi, p. 144; London, Edinburgh, # Dublin Phil. Mag,, xxv. 3rd series, p. 342. t Treloar, Reports of the Saint John d’el Reg Company, xxx. p. 25; xxxi. p. 28. Ante, p. 197. t Ante, p. 191; Table VI. columns 21—3. § Ante , p. 187; Table VI. columns 3—11,15—17. || Ante, p. 188. U After the principal deposit and the North Branch have been wrought; it is impossible to support, in its natural position, the soft, jointed, thin, inclined mass of slate (“ the tongue of killas ”) which divides them at the Bahil. ** Ante, p. 206; Table VI. columns 3—23. tt Ante, p. 207. tfAnte, p. 229; Fig. 18. §§ Ante, pp. 267—8. (HI Ibid, p. 188. Ibid, p. 224. *** Ibid, p. 234. tft Ibid, pp. 245, 249. 324 W. J. Henwood, on the Gold-Mines range—has yielded merely a few thinly-sprinkled grains of gold.* * * * (jf.) The iron-formation—which succeeds, and at times encloses (horses) \ masses of the Itabirite ,— consists in great measure of iron-glance,J mixed in some places with smaller quantities of both black § and brown || earthy iron-ore, in others with oxydulated^f and titaniferous** * * §§ iron, and elsewhere with hydrous iron-ore.tt Sometimes, however, the iron-glance is replaced by pale-brown earthy iron-ore; and quartz —thinly sprinkled with iron-pyrites §§—then becomes a large ingredient. Where micaceous iron-ore abounds |||| the formation bears a schistose character; and even when granular iron-glance is mixed with earthy ores traces of lami¬ nation still prevail; at intervals, however, large bodies are of crystalline and massive structure.*** * The best parts afforded but 0 0000000021 their weight of gold. Ante, p. 249. f Ibid, pp. 251, 265; Table VIII. columns 3, 18, 21; Fig. 21. • t Ibid, pp. 214, 219, 221—4, 227, 237, 243—4, 247, 254, 256, 260—70, 313; Table VIII. columns 3, 6, 9, 12, 15, 18, 21. $ Ibid, pp. 254, 256, 263, 314; Table VIII. columns 3, 6, 12, 15, 18, 21. || .Ibid, pp. 217, 223, 228, 239—42, 246,254, 256—7,262—7, 314; Table VIII. columns 6, 9, 12, 15, 18, 21. IT Ibid, pp, 214, 219, 225, 228, 237, 242, 248, 252, 257, 262, 265, 270, 314; Table VIII. columns 3,15, 18, 21. ** Ante, p. 228. ff Ibid, pp. 225, 246, 2o3. Bulletin de la Society G&ologiquc, de France , xxi, (1863) p. 25. Ante, p. 265. §§ Ibid, p. 256. HU Ibid, p. 254. HH Ibid, p. 269. *** Ibid, pp. 260,270. 325 of Minas-Geraes, in Brazil. The auriferous portions of such crystalline rocks seldom exceed a few inches in width ; * * * § ** but those of the micaceous-iron slates often measure many feet; f and amongst the granular and earthy ores they some¬ times extend several fathoms.^ But even of these the greater part is very slightly sprinkled with gold ; § for the poorer (0*999) nine hundred and ninety-nine one thousandth parts of the (Jacotinga) ore wrought at Gongo Soco, afforded (only 0*323) scarcely one-third || of the entire produce. The great riches of this series have, however, been obtained from certain conformable beds, already men¬ tioned ; which open, at intervals, to a width of two or three, and in extreme cases of six inches, ## for several feet, or even fathoms, in length and depth. These—partaking, like all other metalliferous deposits, the nature of the adjoining rocks—consist, in great measure, of iron-glance, black and brown earthy iron- ore, manganese, and talc ; mixed at times with smaller * Ante, pp. 254, 256, 270. t Ante, pp. 214, 216, 242. $ Ante, pp. 227,245, 255; Table VIII. columns 6, 15,18. § Ante, pp. 215, 219, 222, 224, 234, 236, 242, 245, 247, 255, 257—8, 274, 277, 281. The (Jacotinga) ore stamped at Gongo Soco yielded from 0*000000191 to 0*000000765 its weight of gold. Ante, p. 255 ; Table X. column 9. j| Ante, p. 277; Table IX. columns 44—6. U Ante, pp. 229, 262, 314, 318. **Ante, pp. 228, 230—4, 246, 262—8, 314, 318; Table VIII. columns 5, 8, 11, 14, 17, 20.; Table X. column 13. tt Ante, pp. 216, 228, 230, 232—4, 257, 266—7, 269, 271, 279—80, 283; Table VIII. columns 6, 12,15, 18, 21. 326 W. J. Hen wood, on the Gold-Mines proportions of other ingredients.* * * § The central—which are frequently the most congenial—portions of this matrix, contain rough (nuggets) lumps, flakes, and granules; sometimes isolated, often clustered, but generally united by intertwining threads of gold.f Towards the sides and edges of the hunches , however, smaller grains and particles of gold are more thinly sprinkled through the vein-stones ; £ which—becoming poorer by degrees and at length ceasing to afford gold —merge, ultimately, in the neighbouring strata.§ At Gongo Soco the widest and softest parts of the iron- formation contained several productive beds; || in which—as in those of the clay-slate at Morro Velho —the richest (shoots) hunches ** occurred, as well on corresponding undulations (flutings or ripples ) of the ( Country ) rock, as on the same meridian.These formed in the aggregate less than (0*001) a one- thousandth part of the ore extracted ; but they yielded * Ante, pp. 223,228, 233, 263— 5 , 268, 313; Table VIII. columns 6, 9,12, 15, 18, 21; Table X. columns 13,14. f Ante, pp. 272 — 3 ; Table VIII. columns 6, 12, 15, 18, 21. J Ante, p. 274. § Ibid, p. 325. || Ibid, pp, 272—3; Table VIII. columns 6, 15. An English miner, who afterwards became Captain of a neighbouring gold¬ mine, was one day found sending to the Stamps all the ore he was breaking; unconscious that, within a width of eight or ten inches it contained two thin parallel lines of tough gold. MSS. of the late Captain - Thomas Pengilly. U Ante, pp. 188—92, 323; Table VI. columns 2, 8, 11, 14, 23. ** At Agoa Quente the bunches yielded from 0-000379 to 0*017232 their weight of gold; „ Gongo Soco „ „ 0-003273 „ 0*521123 „ Ante, pp. 231, 235, 279 — 80. tt Ibid, pp. 267—9; Table VIII. columns 15, 18, 21. Ante, p. 269. of Minas-Geraes, in Brazil 327 (0* * * * § 677) more than two-thirds of the gold obtained.* The produce of these central portions, therefore, is as much above, as that of those towards the sides is below, the ordinary yield of the beds wrought in talcose slate at Catta Branca and in clay-slate at Morro Velho . j* In the same mountain-range the mines of Soares J and Camara also yield gold, but on other meridians. Whether the auriferous beds—occur only beneath the surface and after short ranges disappear as well ' •■~ * Ante, p. 977; Table IX. columns 44—6; Table X. column 15. f At Gongo Soco, [of gold; the central portions yielded a from 0*003273000 to 0*521123000 their weight ;, the exterior ,, „ 0*000000191 „ 0*000000765 „ At Catta Branca (1840—1844), the annual averages b ..were „ 0*000006500 „ 0*000001960 ,, At Morro Velho (1838 — 1860), the annual averages b ..were ,, 0 000051888 „ 0*000018691 „ Ante, pp. 179, 255 ; Table VII. column. 25. The cost of materials, labour, &c., at Gongo Soco, from 1826 to 1836, averaged £25 : 13 : 0 Morro Velho, „ 1835 „ 1860, „ 26 : 5 : 4 per lb. (Troy) of gold extracted. Table VII. columns 26, 35; Table IX. columns 46, 64, 65, 67. “ Sometimes in the midst of the poorest minerals we find very considerable “ masses of native silver; a phenomenon which appears to depend on a particular “ operation of chemical affinities, with the mode of action, and laws of which “ we are completely ignorant. The silver in place of being concealed in galena, “ or in pyrites in a small degree argentiferous, or of being distributed throughout “ all the mass of the vein over a great extent, is collected into a single mass. “ In that case the riches of a point may be considered as the principal cause of “ the poverty of the neighbouring minerals; and hence we may conceive why “ the richest parts of a vein are found separated from one another by portions u of gangue almost altogether destitute of metals.” De Humboldt, Political Essay on the Kingdom of New Spain , hi. p. 161. “Whatever may be the positions and dimensions of these bodies of” (tin and copper) “ ore, they are usually altogether isolated and separated from each “ other by the earthy minerals of which by far the largest part of every lode * consists.”—H enwood, Cornwall Geol % Trans,, v. p. 210. X Ante, p, 182. § Ibid, pp. 183, 247. a At the Washing-house. bkt the Stamps. zz 328 W. J. Henwood, on the Gold-Mines upward and downward as at both ends,* * * § ** or—cropping out—are of great but unknown length and depth ; f— are but a few inches,J or many feet, wide; §—follow the joints, || or conform to the cleavage ;^[ particles of gold are disseminated singly through the iron- pyrites ; ## but (nuggets) masses—of larger sizes as their matrix is of better quality j'f—are clustered in the specular ore they contain.JJ F.— Characters of the vein-stones , and proportions of gold obtained from them , at different depths. ( a .) As the metalliferous deposits of Morro Velho are followed downward they enclose masses of slate in greater numbers, §§ become wider |||| and softer, * Ante, pp. 177, 183, 266—7, 269, 299; Table VIII. columns 13—21. f Ante, pp. 178,181,184,188—207, 214, 216, 301; Table VI. columns 3—23. J Ante, pp. 177, 183, 214, 228—32, 262—8, 299, 302 ; Table VIII. columns 5, 8, 11, 14, 17, 20. § Ante, pp. 178, 182—4, 189—90, 214, 216, 240, 253—4, 301; Table VI. columns 4, 7, 10,13, 16,19, 22. || Ante, pp. 181, 187—8, 207, 221, 223, 232, 234, 264, 299, 301—2; Table VI. column 14; Table VIII. column 6. || Ante, pp. 177—8, 182—4, 187—8, 207, 214, 216, 221, 223, 227, 238, 244, 251, 255, 259, 262, 266—7, 269 282, 299, 301—3; Table VI. columns 5, 8, 11, 17, 20, 23; Table VIII. column 1. IT Ante, pp. 184, 194—8, 312, 318, 322; Table VI. columns 5, 8, 11,14, 17, 20, 23. ** Ante, pp. 177, 181, 183,299, 301—2, 312, 320. tt Ibid,, pp. 216 Note 224, 230—5, 271—80, 326; Table VIII. columns 6, 9, 12, 15, 18, 21. Iron pyrites. contains. 47*85 per cent, of metal; Earthy brown iron-ore .. „ . 56*13 ,, ; Iron-glance. „ . 69 00 ,, ; Phillips, Mineralogy (3rd Edition, 1823), pp. 217, 224, 231, Ante , pp. 202, 212 Note ||. $§ Ibid, pp. 190,206. U|| Ibid , p. 199. f If Ibid, p. 194. of Minas-Geraes, in Brazil. 329 afford more arsenical pyrites,* less quartz, f and smaller proportions of gold. ( b .) In the shallower parts of Gongo Soco an im¬ perfectly lamellar structure J pervades the body of granular iron-glance, black and brown earthy iron-ore, manganese, and talc; which—interlaid by these beds, whence the great riches of this formation are derived,§ —is, for some distance beside them, more or less im¬ pregnated with gold. || Somewhat deeper it is more decidedly schistose,If and its chief ingredients are iron- glance and talc ; ** but in these the auriferous bunches are fewer, smaller, and less productive.|f At greater depths a fissile character prevails; iron-glance is to some extent replaced by yellowish-brown earthy iron- ore and oxydulated iron,JJ the talc is mingled with quartz,§§ and crystals of iron-pyrites occur at inter¬ vals; HU but here the deposit contains very little gold.If If In all parts of the mine hard, crystalline, massive iron- glance seems to have an unfavourable influence.*** ( b —1.) At Agoa Quente the iron-glance—every¬ where quartzose, hard, and of schistose structure—is interlaid by two auriferous beds, usually less than one- tenth of an inch, but for short distances, here and there, * Ante, p. 196. f f Ibid, p. 265. f Ibid, pp. 201, 303 205—6. tt Ibid, pp. 265, 283. t Ibid, pp. 269, 324. §§ Ibid, pp. 256, 265, 267, 314, 324. $ Ibid, pp. 262—8, 311, 324. ||[| Ibid, pp. 256, 265, 314. || Ibid, pp. 263-4, 266-7, 271-80. HIT Ibid , pp. 256, 324. H Ibid, pp. 255,281. *** Ibid, p. 283, Table VIII. column 21, ** Ibid, pp. 255,265. fff Ante, pp. 270, 318, 325. 330 W. J. Henwood, on the Gold-Mines several inches wide. # Although they generally con¬ form to the cleavage; one of them is, in a single instance, slightly deflected at a short, thin cross-vein of quartz,f which accompanies one of the joints. The narrower parts consist chiefly of earthy brown iron-ore, iron-glance, and talcose clay; mixed, sometimes, with small quantities of titaniferous iron.J The broader portions likewise contain iron-glance and earthy brown iron-ore; but oxydulated iron, manganese, talc, and felspar clay are also abundant; and quartz is seldom wanting.§ In these grains and small nuggets are im¬ bedded ; sometimes singly, but frequently they are strung together by interlacing filigranes of gold.|| The clusters, however, are fewer and smaller as their matrix —-partaking the character of the neighbouring rock and of the cross-vein —becomes more and more quartz- ose at greater depths; but in both the beds these hunches occur on the same parallels. From such groups some twenty-nine-thirtieths (0966) of the entire pro¬ duce are obtained.**' About one-thirtieth (0033) is also extracted from the adjoining rock; which for short distances beside the richest hunches is thinly sprinkled with gold, ft * Ante , pp. 230—2, 235. f Ibid, pp. 232—4. % Ibid , p. 230. § Ibid, pp. 228, 230, 233. || Ibid, pp. 229, 233. U Ibid, pp. 229—35. ** Reports of the Imperial Brazilian Mining Association, xliv. p. 7 ; xlv p. 7; xlvi. p. 10; xirvn. p. 7; xi/vm. p. 6 ; xlix. p. 9; l. p. 7; li. p, 10; hi. p. 7; Lin. p. 18. tt “ The riches seem nowhere to extend far from the Jacotinga." —Henwood, Ibid, xliii. second part, p. 2. of Minas Geraes , in Brazil . 331 The following columns show the proportions of gold afforded by ore produced at different depths, in the clay-slate at Morro Velho and in the iron-slate at Gongo Soco and Agoa Quente. Clay-slate. Iron-slate Morro Velho. Gongo Soco. Agoa Quente. Depths. fms. Proportionate yield of gold by crude ore.* Depth. fms. Proportionate quantity of gold extracted by each European miner.f Depth. fms. Proportionate quantity of gold extracted.^ Surface to 50*0 1* 7 to 21 1- 12 to 27 1- ' 50* „ 100-0 0-956 21 „ 41 0-790 27 „ 37 0-462 100- „ 142-8 0-912 41 „ 55 0-450 37 „ 43 0-283 Thus, at progressively greater depths, the productive beds—so far as they are yet wrought—continue to yield smaller averages of gold. And these decrements are much more rapid when—as in the Jacotinga —rich bunches are aggregated in narrow layers; § than where —as in the quartzose and pyritous deposits—gold is more generally diffused through the matrix. || G.— Quality of the gold in different rocks and at different depths. (1.) Quality in various rocks. The gold,—although disposed in much the same manner,—is of somewhat different quality in every member of the system. * Ante, pp. 205—6, 328; Table X. column 15. f Ante, pp. 284, 329; Table X. column 15. + Reports of the Imperial Brazilian Mining Association, xliv,—liii. Ante, pp. 227—235; Table X. column 15. $ Ante, pp. 215 Note f, 216 Notes 11, 223,227-235,263-8, 271-4, 279-80. |1 Ibid, pp. 184, 194—8. 332 W. J. Henwood, on the Gold-Mines Rocks. Vein-stones. Qualities. r Extremes. > Means. Granite .. • • Granite—oxydulated iron .... 22 0-3—22 3-9 22 2-6* f Quartz—earthy brown iron-ore— talc t (Lower) . 20 3-0$ — | Talcose slated > 22 1-2 1 Quartz—talc—brown and black 1 l earthy iron-ore ^ ( Upper) .... — 23 3-5j Quartz-rock • • Quartz—red iron-ore. — 23 0 01| r Quartz—earthy brown iron-oreTI. — 23 O-O') Clay-slate i < Quartz — iron* pyrites — copper- j* § 20 2-0 i pyrites—arsenical pyrites**.. 17 3-8 — j r Iron-glance — earthy black and Iron-slate < brown iron-ore, talc, and man- l ganese . 20 0-0tt 20 3-0*i 21 3-5 These averages must, however, be regarded only as approximations. In the granite, in both the talcose slates, and in the quartz rocks, the gold is—with a few exceptions—of somewhat greater purity than in the clay-slates and in the iron-formation. And the enormous produce of Motto Velho is of inferior quality to the yield of smaller * Percival Norton Johnson, Esq., F.R.S., MSS. Cock, London, Edinburgh, and Dublin Phil. Mag., 3rd Series, xxm. p. 16. Ante, p. 175. t Percival Norton Johnson, Esq., F.R.S., MSS. Table X. column 16. $ Lower talcose slate. Ante, pp. 176—80; Table X. column 16, § Upper talcose slate. Ante , pp. 298—304; Table X. column 16. || von Spix und von Martius, Reise in Brasilien , i. p. 408. Ante, p. 180; Table X. column 16. IT In talcose clay-slate. Ante , pp. 182—3, ** Table VII. columns 27—9. ft Table IX. column 47. J+ Senr. Guarda-mor-Geral, Manoel Joze Pires da Silva Pontes, Voyage dans Provinces de Rio de Janeiro et de Minas Geraes (Saint Hilaire), i. p. 273. Ante Note f ; Table X. column 16. During the year 1848 the gold obtained near Itabira averaged about 20 carats fine. . of Minas-Geraes, in Brazil. 333 mines in other parts of the clay-slate. In like manner the large quantities obtained at Gongo Soco are of lower assay than the returns of inconsiderable deposits in the iron-slate elsewhere. The calcareous strata are so thin, and the proportion of gold they afford is so small, that its character has never been determined. Respecting the fineness of gold contained in distant parts of any single formation at the same horizon, we know but little. Tables VII. and IX .—compiled from Reports of the Saint John d’el Rey Company* and the Imperial Brazilian Mining Association f—supply, however, the means of ascertaining approximately (2.) The quality of gold obtained at different depths in two of the largest and most productive mines. Depth. fins. Clay-slate. X Morro Velho. Quality of gold. . . A Depth. fras. Iron-slate,§ Gongo Soco. Quality of gold. _A*_ ( Actual, carats grains -i Comparative. r Actual, carats grains Comparative. Surface to 50*0 18 3-687 1-0 41 to 48 21 0-448 1.0 50* „ 100-0 19 0-183 1*006 48 „ 70 20 1-774 0-968 100- „ 142-8 19 0-228 1-008 Whether the improvement in quality which, at progressively greater depths, gradually takes place in the gold of one mine, or the decline in that of the other; is owing to differences in the strata, || the vein- * Till.—xxxi. f xv.— lxii. % Ante, pp. 205, 285 ; Table X. column 16. § Ante, p. 285; Table X. column 16. || Ante , pp. 185, 25426-2, 269, 312—13, 321, 324. 334 W. J. Henwood, on the Gold-Mines stones,* ** and the alloys, f or to other causes; J can hardly be discussed with advantage, in the present, imperfect, state of our knowledge. H.— The alloys of gold in various rocks and at different depths . (1.) Nature and proportion of alloy in various rocks . Rock. r Granite. Palladium r i Silver ... Tellurium Talcose slate-^ Antimony Bismuth . Tellurium Quartz-rock .. Silver .... Clay-slate.... Silver .... Nature. (Lower)' Alloy. _A— Proportion of mass. _>_ Extremes. 0 050000—0-08000$ 0-179300—0*205000 Means. 0*070000 0114583 0 020834 ^ Traces. Traces. 0*194200 * Ibid, pp. 194, 262— 7, 313, 318, 325. t Ibid, pp. 206, 286; Posted, p. 335. t Ante, pp. 199, 267, 270, 310. §Percival Norton Johnson, Esq., F.R.S., F.G.S., &c., MSS. Cock, London , Edinburgh, and Dublin Phil. Mag., 3rd Series, xxm. p. 16. || Percival Norton Johnson, Esq,, F.R.S., F.G.S., &c., MSS. ^ Ante, p. 180. ** John Hockin, Esq., Managing Director of the Saint John d’elRey Company, MSS. Table VII. columns 2, 31. ft Analysis of gold from Morro Velho (October, 1864). Gold . 07499 Silver . 0-1793 Lead. 0 0180 Bismuth . 0*0135 Copper. 0-0045 Antimony ..... 0-0030 Arsenic ... 0-0105 Iron..... 0 0195 Mercury (traces) and loss. 0-0018 1 - John Hockin, Esq., Managing Director of the Saint John d’el Rey Company, MSS. of Minas-Geraes, in Brazil, 335 Rock. r Alloy. _A_ Nature. Proportion of mass. -A- Extremes. Means. ■\ Clay-slate Copper. •, Lead..... Bismuth. , Antimony Arsenic . * * * * * -Traces. f Iron-slate.. <( Silver ... Palladium Copper .. Platina .. f •• tt .. § .. f •• 0-044884—0-083333 0-038929—0 048054 0 019444—0-037413 0-000407—0-001276 0-053704 0-042100 0-025374 0-000811 Thus silver is more or less plentiful in every member of the succession,|| except the first. * Ante, p. 334, Note ft t Reports of the Imperial Brazilian Mining Association , xvi.-xxxi., Financial Statements. Table IX. columns 47—50. Ante, p. 236. J Ante, p. 215. § Ibid, p. 334, Note.[| [| The mine-gold of Siberia is alloyed with silver, copper, and iron in the follow¬ ing proportions Metals, and their proportions. ( - A ---1 Mines. Gold. Silver. Copper. Iron. Totals. Biel . 0-8740 *■* * * § »•*.{oliu Beres ™ .I 0-9378 Katharinenburg . 0-9280 Siranowski (Altai) .. 0-6098 .. 0*1260 .. — .. — .. 1-0000 .. 0-0705 .. — .. — .. 1-0000 .. 0-1064 .. 0-0009 .. 0-0035 .. 0-9973 .. 0-0803 .. 0-0009 .. — .. 1-0000 .. 0-0594 .. 0-0008 .. 0*0004 .. 0-9984 .. 0-0702 .. 0-0006 .. 0-0008 .. 0-9996 .. 0-3838 .. 0-0033 — .. 0-9969 “ L’or et la platine se presentent dans l’Oural tres-frequemment dans les memes “ localites, il pouvait arriver que ces deux metaux se trouvassent aussi combines “ -chimiquement.” * * * “II parait que l’or natif contient toujours au moins une petite quantito d'argent, “ de cuivre, ou de fer.” * * * “ En general la pesanteur specifique de l’or, lorsqu’il a ete fondu, est un peu “ plus grande que celle de l’or tel que le presente la nature.” * * * “ L’or que se trouve dans les filons a aussi une composition differente dans les “ diverses parties d’une meme mine.” * * * Gustave Rose, Annales des Mines , 3me Serie, v. p. pp. 157—170. “ L’or et l’argent se trouvent unis ensemble dans la nature sous forme de cris- AAA 336 W. J. Henwood, on the Gold-Mines Copper appears in the fourth and fifth strata ; but in, at least, one instance # it is mixed, rather than alloyed with the gold. Bismuth and antimony are not uncommon in the second section ; f and both, as well as lead and arsenic, are met with in the fourth.J Palladium occurs in the first individual of the system; and—unrecognised in the intermediate formations— abounds again in the fifth.§ Tellurium abounds in the second ; and,—undetected in any intervening deposit—re-appears in the last member of the series; but, as in the upper, it is also sometimes mixed with the gold.|| “ taux, en toutes sortes de proportions, * * * * § * * , En general, les cristaux “ dodecaedres sont les plus riches en or, et ils n’en renferment pas moins de 0‘91. “ Yiennent ensuite les tetraedres, puis les octaedres.” Awdeef, Annales des Mines, 4me Sdrie, in, p, 845. * von Eschwcge, Pluto Brnsiliensis , p. 298. Ante , p. 236. f Ante, p. 180. X John Hockin, Esq., Managing Director of the Saint John d’el Rey Company, MSS. § “ When the Council determined in 1845 that Palladium was the fittest sub- “ stance to employ for the Wollaston Medal, Mr. Percival Norton Johnson, “ F.G.S., expressed a wish to present Palladium for that object, as a token of “his grateful esteem for Dr. Wollaston. The Palladium presented then being “ at length exhausted, Mr. Johnson has again most handsomely offered to present “ the Society with the requisite metal.” Quarterly Journal of the Geological Society of London , vn. (1851) p. 2. This palladium was separated from the gold of Gongo Soco. t| The thieves by whom a large consignment from Catta Branca was stolen on its arrival in London, were traced and convicted from Mr. Johnson’s knowledge, that the gold was associated with tellurium. i( From amongst the stamped ore of Catta Branca I picked out particles of “ tellurium.”— Percival Norton Johnson, Esa., F.R.S., F.G.S., &c., MSS. In Virginia the talcose slate is also interlaid by beds of quart?; which, at the Garnett §• Moseley mines, afford gold alloyed in like manner with tellurium. Postea. Henwood, Cornwall Geol Trans., vn. p. 228. Ante, p. 180. of Minas- Gerocs, in Brazil . 337 Platina is peculiar to comparatively shallow parts of the fifth group; but—occurring even there in small proportions,—it gradually disappears at greater depths; although the other metals, with which it had been associated, still abase the gold at a yet lower horizon.* Platina. and palladium are sometimes accompanied by minute quantities of still rarer metalsbut whether these exist in this district is unknown, as the gold is seldom examined for other than commercial purposes. The following columns show the alloys natural to every member of the auriferous system :— n Rocks. A t 1 'i Alloys. 1 Granite. Talcose slate. {Lower.) J Q,uartz-rock. Clay-slate, j Iron-slate. Talcose slate. {Upper.) Totals. Silver .. — * * * * * 5 Copper .. — ? — * > • 2 Antimony. — * — * — ? 2 Bismuth . — * — * — ? 2 Lead .. — — * — ? 1 Arsenic .. — — — * — — 1 Palladium * — — — — 2 Tellurium. — * — — — * 2 Platina .. — — — — * — 1 Totals.. 1 4 1 6 4 2 18 * Ante, p. 286; Table IX. columns 48—50 ; Table X. column 17. t Tennant, Phil. Trans, xcrv. (1804) pp. 414, 416. Wollaston, Ibid, p. 419. 338 W. J. Henwood, on the Gold-Mines It has been already shown * * * § ** that portions of the auriferous beds sometimes follow the joints for short distances, and thus intersect kindred strata; but they never, in a single instance, extend to even one other member of the system. Nor, indeed, are adjoining rocks, of diverse character, ever rich,—or more than slightly productive,— in the same neighbourhood.f The different alloys characteristic of gold in imme¬ diately sequent groups, therefore, occur, generally in distant districts. (2.) Proportion of alloy at different depths . Clay-slate. Iron-slate. 4 Morro Velho. Gongo Soco.|| Nature and proportion of alloy. Nature and proportion of alloy. .A. Depth. fins. t - Silver. Copper, Lead, &c.J Depth. fins. r • * Silver. Platina. Palladium. -> Copper.1T 50* to 100* 0*192400 ? 41 0-058814 0-001276 0-038929 0-019444 100- „ 142*8 0*199800 — 48 0-054759 0-000711 0-041974 — 55 0-047614 0 000407 0-042700 — 62 0-044884 — 0-048054 0-03741& Means • • • • 0*194200* ? — 0-052991 0-000811 0*042100 0-025374 * Ante, pp. 181, 187, 223, 264, 298, 301—2, 311, 318—19, 321, 323. f Ibid , p. 174. % Ibid, p. 206; Table VII. columns 2, 30; Table X. column 17. § John Hockin, Esq., Managing Director of the Saint John d’el Rey Company, MSS. Ante, p. 334. || Ante, p. 286 ; Table IX. columns 48—51; Table X. column 17. II Percival Norton Johnson, Esq., F.R.S., &c., MSS. ** “ A Gold-Hill (Californie), on exploite un gite remarquable par la grande of Minas-Geraes, in Brazil. 339 The foregoing details supply less information than might have been desired; but they embody all within reach. The proportion of each—irrespective of every other —alloy, at various depths, in rocks of the same, and of different, series ; may, perhaps, be more readily seen in the following, than in the foregoing, columns. “ quantite d’or qu’il a fourni dks les affleurements. Ce gite se compose d’une ** s£rie de veines de quartz juxtaposees l’une a 1’autre, sortant d’un terrain de “ schistes metamorphiques au pied d’un roc 6leve de diorite. Ce gisement se “ presente comme un puissant filon reconnu sur 180 metres de long, large de “pres de 40 metres, incline de 45° du cote de la diorite Eruptive, et presentant “ une masse de quartz aurifere d’au moins 25 metres de large. Le gite est coupe “ en deux par un banc de schiste veine de quartz, ayant 15 metres de large. La “ partie qui est au-dessus de ce banc be schiste se compose de deux filons de “ quartz compacte de 1 a 3 metres de puissance, comprenant entre eux une veine de 2‘5 a 4 metres d’epaisseur, formee d’un sable quartzeux crystallin, empate “ par de l’argile et de l’oxyde de fer. Ces argiles contiennent aussi par places “ de l’oxyde de manganese en essez grande abondance pour les colorer en noir. “ Les deux filons de quartz compacte sont auriferes, mais infinement moins riche “ que la veine qu’ils comprennent, sur laquelle s’est concentree l’exploitation.” * * * * “ La partie du gite, situee au-dessous du banc de schiste qui le recoupe en “ deux, renferme trois filons de quartz compacte, comprenant entre eux deux “ autres veines argileuses et quartzeuses, qui sont encore celles de plus grande “ richesse.” * * * “ On trouve a Gold-Hill un exemple remarquable de ce fait que, dans certains u filons, a mesure que les travaux gagnent la profondeur, l’or diminue et l’argent “ augmente. Ainsi, a Gold-Hill, les proportions relatives de l’or et de l’argent “ ont varie comme suit: “ Pres des affleurements.... “ A 20 metres de profondeur.... “A 50 )) )) or, 651; argent, 300; „ 462; „ 450; „ 33; „ 931.” “ Ce gisement de Gold-Hill n’est pas, a proprement dire, un veritable filon, “ les travaux faits pour le reconnaitre ont montre qu’il ne s’etendait pas au dela u de 200 metres en direction, et que sa puissance allait en diminuant rapidement “ du milieu du gite a ses extremites, de sorte qu’on doit considerer cet amas de “ quartz aurifere comme un gisement de contact.” La.ur, Annales des Mines, 6me Sdrie, in. pp. 428—30. 340 W. J. Hen wood, on the Gold-Mines Depth. fins. Clay-slate. Morro Velho .* ** Nature and proportion of alloy. -A. Depth, fms. • Iron-slate. Gongo Soco.% Nature and proportion of alloy. -Aw r Silver. \ Copper, Lead, &c.f Silver. Platina. Palladium. ~ A Copper.§ 50’ to 100* 1* ? 41 1- 1- 1- i- 100- „ 142 8 1-020 — 48 0-931 0-557 1-078 — > 55 0-809 0-319 1-097 — 62 0-763 — 1 234 1-924 Means.... 1-009 ? — 0-901 0-635 1-081 1-305 Whether the gold which, in similar vein-stones and rocks, is associated with the same metals in different parts of the Province ; || as well as that which, in other matrices and strata, contains different alloy, in the same neighbourhood ; assumed its present place, at various times, ## or at once,—however inviting as a subject for speculation—can scarcely be discussed, with advantage, in a descriptive memoir. I. Cross-veins , N such as those which intersect the strata, for considerable * Ante, p. 338, Note *. f Ibid, Note f. $ Ibid, Note }. Ibid, Note §. || Ante, pp, 176—80, 298—304; 184—209 ; 214—98. H Ibid , pp. 179—80,184; 177, 181—2, 237—41 ; 182—3; 248—96. ** “ II est done possible que ces filons (de la mine de Beresoio ) aient ete formas “ a diverses fepoques.”— Gustave Rose, Annates des Mines, 3me Serie, v. p. 169. “We believe, that with the present amount of evidence, it would be unsafe to “ attribute the origin, of either platinum or gold ” (in the Ural), “ exclusively “ to one mode of formation.”— Murchison, de Yerneuil, & von Keyserling, Russia in Europe § the TJral Mountains, p. 484, of Minas Geraes , in Brazil , 341 distances, in other countries; # are unknown in this district. In the granite of Candonga ,f nevertheless, portions of the auriferous beds,—which, at intervals, assume abnormal directions, and are poorer than the rest,— have been sometimes supposed to be affected by,—or even to be themselves— cross-veins, J At the Camara mine short, conformable beds of gold-bearing quartz, often end abruptly at the joints; but are now and then rediscovered, in contiguous slices of the clay-slate, by turning towards the right-hand; § sooner or later, however, they all disappear. Both the Itahirite and the Jacotinga are traversed by cross-veins of quartz ; which, at Agoa Quente || and Gongo Soco ,^[ seldom exceed a fathom in length or depth, and are generally less than an inch in width. * Thomas, Survey of the Mining District from Chacewater to Camborne, p.p. 22—3. Carne, Cornwall Geol. Trans., n. pp. 108—9. Forster, Section of the Strata from Newcastle to Cross Fell, pp. 73, 112, 206. Phillips, Geology of Yorkshire, Part n., pp. 99, 104, 107—8, 110-—15. Fox, Report of the Royal Cornwall Polytechnic Society (1836) p. 88. De la Beche, Report on the Geology of Corntcall, Devon, % West Somerset, p. 303. Henwood, Cornwall Geol. Trans., V. p. 255. Smyth, Records of the School of Mines, i.pp. 376, 394—9. Moissenet, Annales des Mines, 5me Serie, xi, pp. 378—80—6, 592—6—8. Wallace, On the Geological Structure of Alston Moor, pp. 55, 104. Ante, pp. 124—6. Mr. Carne’s Memoir was communicated to the Royal Geological Society of Cornwall in 1818; Mr Thomas’s work appeared in 1819; but Mr. Fox inci¬ dentally shows (Cornwall Geol. Trans, n. PI. i. Remarks), that the latter had been published, before the former was put to press. t Ante, pp. 176, 311, 320. X H. von Helmreichen, MSS. § Ante, pp. 183, 247, 327; Fig. 14, II Ante, pp, 225—6; Fig. 17, ^ Ante, pp. 286—7; Fig. 25. 342 W. J. Henwood, on the Detrital Gold By some of these the strata are simply severed; but by others they are slightly displaced, and in such cases each bed in the upper side (hanging-wall) occupies a higher relative position than its counterpart in the lower side (foot-wall) of the cross-course . But, small as the displacements are, they diminish by degrees and at length disappear; * ** as—from their centres towards their circumferences—the cross-veins gradually decline, and ultimately merge, as well upward and downward as at either end, in undisturbed layers of quartz. Detrital Gold. In the beds and banks of rivers, as well as on the declivities of many mountains, the rock is covered with ( Cascalho ) sand, gravel, pebbles,')' and subangular * Henwood, Cormcall Geol. Trans, v. pp. 88, 381. f “ Wherever the margin formed a flat, or level, the cascalho continued under “ the surface to some distance, appearing like a continuation of the bed of the “ river, which, in all probability, it was, as the river is known to have been much “ wider formerly.”— Mawe, Travels in Brazil, p. 268. “ On trouvait autrefois beaucoup d’or dans le voisinage de la riviere de Caete.” De Saint Hilaire, Voyage dans le district des Diamans et sur le littoral du Bresil, i. p. 127. “ Congonhas do Campo doit sa foundation a des mineurs qui trouverent beau- “ coup d’or sur les rives du Rio de S. Antonio, ainsi que sur celles du Rio das ** Congonhas et tout autour du village : le flanc des mornes d6chirb, bouleverse “ de toutes les manieres, atteste assez les travaux des ces hommes aventureux.” Ibid, p. 201. von Eschwege, Annales des Mines, vm. p. 409; Pluto Brasiliensis, p. 229. Gardner, Travels in Brazil, pp. 505—6. Claussen, Bulletins de VAcadimie Royale de Bruxelles, vm. Ire partie, p. 335. “ The gold alluvia of the Ural (sand it can very rarely be called) is a gravel “ seldom less coarse than that around London and in the east of England, and cc for the most part a shingle, composed chiefly of moderately-sized fragments of of Minas Oeraes, in Brazil. 343 rocks* of larger size, imbedded in ferruginous clay. All these, as well as the particles and grains of gold mixed with them, may be traced to their parent strata in the neighbouring Serras .f Beyond these beds of (Cascalho) detritus the first seekers for gold did not extend their labours. Early in the last century, however, the forests were recklessly destroyed J by the (Rogeiros) farmers. Laws “ the adjacent rocks.”— Murchison, he Verneuil, & von Keyserling, Russia in Europe and the Ural Mountains , i. p. 476. “ Le terrain diluvien ancien se compose d’une serie de couches de galets de “ sables et d’argiles superposees le plus souvent par ordre de grosseur. * * * “ Tout ce terrain renferme de l’or. Les couches les plus riches sont toujours “ celles de galets au de gros graviers.”— Lour, Du gisement de Vor en CaliJornie, Annales des Mines , 6me Serie, hi. p. 411. * “ There is a difference between the cascalho in the mountains and that in the “ rivers; the embedded stones in the mountain-casca^Ao are rough and angular, “ but in that of the rivers they are rounded.” Manoel Ferreira da Camara, History of Brazil (Southey), hi. p. 827. f Between Inficionado and Bento Rodriguez “ I saw but little soil fit for “ plantations, it being generally of a clayey nature, intermixed with a coarse “ ferruginous gravel, or the debris of the schistose rocks of the Serra ” de Cara^a; “ and everywhere this soil has been turned up in search of gold.” Gardner, Travels in Brazil , p. 506. “ Unlike * * * other chains which burthened with much detritus have cast “ off portions of it to great distances from their flanks, the sides of the Ural are “ void of all such far-transported or rounded blocks; every loose fragment having “ been derived from an adjacent elevation, and having been usually washed down, u in strict relation to the chief existing features of the land. In fact the term “ drift is not correctly applicable to these Uralian masses, which are purely u local.”— Murchison, de Yerneuil, & von Keyserling, Russia in Europe and the Ural Mountains, i. p. 476. “ La couche aurifere d’Akstafa (au sud du Caucase) est recouverte d’alluvions “ improductives formees de deux couches superposees, savoir : un metre d’argile “ grise et un metre de galets dissemines dans la meme argile. La composition i( min6ralogique de ces galets est la meme que celle des roches avoisinantes.” Ulauyaly, Annales des Mines , 5me Serie, m. p. 832. “ The gold-bearing gravels ” of Victoria (Australia) “ are the result of the “ immediate waste of older masses, and have not been transported far.” Selwyn, Quarterly Journal of the Geological Society of London , xiv. p. 536. J “ A farmer made no scruple of setting fire to the woods, and laying waste “ a tract of ten or twelve miles round his miserable plantation. The evil which BBB 344 W. J. Henwood, on the Detrital Gold —still unrepealed, but never enforced—were imme¬ diately enacted for their protection; * * but the mischief they were intended to prevent had been perpetrated; many of the springs—-already laid bare—had vanished; and the works carried on by aid of the streams they afforded, had—of necessity—been abandoned. Of the (Regos) water-courses, thus rendered useless, many may still be traced, as well across the (Campos) open country, between Camargos and Inficionado, Cattas Altas and Brumado, Caethe and Cuiaba, as in other parts of the Province, where now the traveller scarcely finds means to quench his thirst. Beds to which water was easily brought from neigh¬ bouring rivers, however, were wrought either until they were exhausted, or until the workmen found more profitable employment in the mines. From all within reach, therefore, most of the gold has long f since been “ would inevitably result from this havoc, was early foreseen, and Gomes Freire “ de Andrada, at the commencement of his long administration, endeavoured to “ prevent it.” —Southey, History of Brazil, in. p. 825. * Regimento dos Superintendentes , Guardos Mdres, et Officiaes Deputados par as Minas do Ouro. Bando ou Additamento ao Regimento Mineral , 13 de Maio de 1736. Ante, p. 138, Note. t “ Two lance-shaped arrow-heads ”—presented to the Museum of American Antiquities at Copenhagen by Mr. von Helmreichen—were “ obtained in the “ process of washing the diamond-yielding cascalho, a soil consisting of sand and “ small stones ; and both were found in the bat&a or washing-bowl; but whether “ they had been imbedded in the cascalho itself, or in the alluvial formation, Mr* “ von Helmreichen was unable to ascertain. One of the arrow-heads is of petro- ^ ^ w P.J3 nomm >0 ^ oo TO s o w H H Ph Ch .O o *C) o O 1 f-« o p< o u Pi -£§> o 3 w <§» CO o ©I .-H »“t I—I o o o o o o o o o o o o CO o CM l>- r-t O o o o o o o o o o o o o ' M w • fi4 jd P4 *p| o o S o 2 - w 0 O '♦-J *r -1 H«12 p. Q. v IS HNaco . CO CO O CO co rH CM UD t-1 Tj« —i ci ri< CM H O o o o o 1 CD *a • • • • hNqo to Ol (MNOtD co s ^ 1-4 O O © i—4 c H Cll^ Cl 1-4 M PC[N CT> CO CM f-i o • i -4 fH P< os N Pi O H 5? W s § W > o O .§ ►o *tS» &2 So 00 g : . » * rf * C3 oj f>j *3 g fl rO t» o d to »h O ~ 3 ,i4 cS r© 'c?'® c3 ci PI -t-> Pi A VU bp a ‘m d .13 o P"t Ph cS * > • v 9 '« . s«* o ,i 4 Mo • • ** • ♦ ^ ^4 m <72 d • H 'O N .x: M to m 22 • i-^ rd o xn 2 2 e>D M -*-> 1-4 O *4} • H CD fc4 5^ rM 03 C /3 02 ^4 03 c3 M M 03 2 O r* u a k . o d g dSS ,d *rt ^4 o .13 to fc* 55 HrO ^3 03 a ?3 p! O \Q> Pi 3 S-l o i* rM 03 .3 3 ^4 NlOONNi-ICOCOtOTHlOHO T}< CM ONMOD'CtThMONCOCOtO'^ O !>. 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J-i a o O eS O H In the year 1851, therefore, each man employed by private parties, on an average treated 182*3 tons of sand, and extracted 0*615 lb. of gold on Government Works, „ 190*3 „ 1*704 99 On all gold obtained by individuals from the sands of Siberia, the following Royalties (Rents and Dues) are reserved to the Crown Minas-Geraes, in Brazil . 347 smaller and lighter portions of their beds, they are 05 O tn o PS ■§ £ Pi CO rH 03 ■s s o > o o CO 4) o rS O >1 Pi CD J-i *3 p a> CD p CD o u o Pi to CO •k «k 6 U1 £ o CO N oo CO ••* Tjl ^ s »§ M o g O rP ° ^ t—t To P g o O tO t^tO rH 00 -*■» N—' OT V_/ CO ®0 '■Q W ^ * O o 2 -P a*** to PS o pS f-H c3 CM C3 p p p p O O o o ^ Ok •s 9% «s •* 0 C H • • • • • • • • • • • • • • • • • • • « • • • • • * * • /—\ /^k ✓*—N CO CD o o o o o o o o b. to 05 CO N CD »o r-H cq to O »o O to O o -P Cw tH co to p rH rH cq cq CO rH W3 o O o s i _4 o PS o •*-> o s In 1851 the Government granted 238 licences to search for gold. 348 W. J. Henwood, on the Detrital Gold utterly inadequate to the removal either of large rocks or of the heavier materials which are often ores of iron. Even whilst in flood they seldom overflow their banks, or rise to erode the strata. Operations usually commence with May and end early in September, when snow begins to fall. This, however, does not arrest the explorers , who continue their labours through the winter ; the frost hardening the marshy ground, and thus facilitating their work. But sometimes the sand is thawed with fire, and washed with tepid water ; fuel—found on the spot—costing but little. Contracts, between the explorers and the workmen , stipulate the number of barrows of sand each person is to remove daily; but having performed his task, the labourer disposes of his time as he pleases. The cost of treating the poorer sand averages (about one rouble and eleven copecks per cubic m£tre) nearly two shillings and nine pence per cubic yard. But, in addition to the terms of their ordinary agreements, the proprietors endeavour to encourage honesty and to prevent theft amongst their workmen , by offering rewards; which vary,—in proportion to the richness of the sand,—from (57'5 to 85 silver copecks per zolotnick ) about eight pence to one shilling per pennyweight of gold obtained. Each workman receives, beside his wages, 0*902 lb. (Avoir.) of meat, with an allowance of oatmeal daily; as well as bread and kwass (a sort of beer) “ & discretion .” How the explorers manage to get through their rough work during winter is truly surprising; as huts made with the branches of trees, and often covered with snow, are their only shelter from the severity of the weather. In spite of these hardships, however, explorers are always on the increase. Ulatjyaly, Annales des Mines , 5me Serie, in. pp. 821—30 (Abstract). Whitney, Metallic Wealth of the United States, p. 89. Between Bale and Bingen the Rhine winds through an enormous deposit of sand, gravel and shingle; made up, in great measure of granite, micaceous and talcose quartz-rocks of schistose structure, siliceous sandstones, hornblendic slates, porphyries, serpentines, and limestones. A few of these resemble the volcanic rocks of Kaiserstuhl, others seem to have come from the Jura, many are natives of the Yosges and of the Black Forest, but the greater number b^ far are of Alpine origin. Traces of gold occur in the pebbles of quartz which are obtained from this formation for paving the streets of Bale, Strasburg, Brisach, and other neigh¬ bouring towns. The sand and gravel, as well in both banks as at several miles from the river, are more or less auriferous; but they yield only from 0*000000090 to 0*000000100 their weight of gold. These, more ancient deposits, are, at intervals, overlaid by the Loess (a forma¬ tion of argillaceous matter, carbonate of lime, quartzose sand, and micaceous clay; enclosing land-shells of recent species), which is utterly barren. Daubree, Annales des Mines, 4me Serie, x, pp, 1—21. ( Abstract-) Gonqo Soco. a Morro Velho. b Long. 43° 30' W.; Lat. 18° 58' 30" S.; Long. 43° 50' W.; Lat. 12° 58' 20" S. about 3,360 feet above the sea. about 3,250 feet above the sea. of Minas-Geraes, in Brazil. 349 During the calms of the hot season heavy rain* Means. Rain. ins. H O NCO H Oi IQ lO H (O O O (NOOMCOWCONNHCOCOCO ioioDHHOOO^^QCO rH rH !>. 05 oo CD 1863. Rain. ins. CDHfflOD VO IQ D 00 00 CO 05 r-1 rH VO ,rH i O 'l 1 H 05 . I* I.... COlMOCMrH lo 1 N ic H oo rH rH VO • T—1 VO 1862. Rain. ins. CO O rH rH CM l>- CO CM vo 00 >o ®i^>o >0 H CO | HOOOCO MibilHH OH 1 © CM rH O0 rH rH » a 59-32 1861. Rain. ins. IMCOONOOHCONHCD CD 1(3 CNNCOCO^NIOOCOD COCO rH©©©©©.TH rH rH rH CM 80-02 1860. Rain. ins. CO O rH rH CO CO i—I 05 CM 05 CO H H O O O . - 05N>0 00 vb vo 0 05 i—1 © 00 rH 05 05 rH CD 05 rH , CO MNH O NCNCMHO^C 1 © rH *b 00 CO rH rH rH . 68-76 1858. Rain. ins. O rH rH CD CO © 00 © CM rH OO IQ CO CO CO CO . vo rH *0 - - 05 rH CO CO rH CD CO 05 *•*•«••• • • • • »OrHOOOOOOOOOrHCb rH rH iH 03 »—t o 00 1855. j Rain. ins. o oo *o o 05 ioooo»o CO rH 0 05 CO CM rH (M rH (M IH e . • ’3 2 2 es •” PS ^ OCOIOOCONCOCONOIO^ C0OrHC005 t-rHC0*0CDCD05 «•••••••• • • • nonnhhhoniooco CM CM rH (MH 121-08 Me: Rainy days. ■ctCHDNN*ODOODHHlO (M CM rH rH rH CM CM 176 c • . 03 C CMCOrHCOCMCMt-rHOrHOOM ODCOrHCOCMCOcOOrHrHbrt-- *b 1>- 00 rH 66 iHO«®N CO rH rH rH CM r—i CO r-H 18 Rainy days. t-— cMCMOrHrHCOOCOOSiMCO CM CM CM CM rH CM CM 177 • £3 • •a w • ^ a CoS'" rH VO O 00 00 CD rH O rH *0 CM CD rH CM CO O ^ 05 CM rH *0 tH C-l H CD HcOtrVOCMcbiHOCO^OOCD O) rH rH rH CM IH <£> O rH 1? Rainy days. OCMVOVOOCOrHCOOVOCMOO M M rH rH i—C rH rH CM CM s .5 “ . rt .S no tf ~ rH M CO rH CO © 05 CO *0 CO rH CD CO © CO O CD O N O CO i—t rH CO CO . CM CM CM rH CM rH ‘O l- rH CM r-H 18 Rainy days. CD005VOCDrHCMOC005050 CHI CM rH rH rH rH rH rH rH CN co CO rH V_. Months. d X> b v-c S a P!^*5P&,-H > O ui a yy 1 05 CO SO m p! • H co . o CM co 03 SO ? O O O K5 ; O CO rH rH CO HCiOOH Pi d )“S rH CO ■p o O P! o o fH 0) £ o o o m o o A O o +» cj w Pi • H c 3 5 h C/3 O • H s -H cj d d d r ^-« r w g CD H xi co .2 •s co w - CM CO rH VO CD CM iM CM > O aHenwood, London, Edinburgh, and Dublin Phil. Mag., xxviii. p.*3G6; xxx. p. 364; xxxii, p, 425. 6 J. N. Gordon, Esq., Resident Superintendent at Morro Velho , MSS. 350 W. J. Henwood, on the Detrital Gold sometimes alternates with a thick drizzle for eight or ten days in succession ; saturating the soil, loading every leaf with moisture, and causing many landslips.* * The undermentioned effects of rain has been recorded at Gongo Soco On the 2nd of December, 1827, a shower, which lasted but a quarter of an hour, washed so much rubbish from the mountain-side, that it filled great part of the ancient ( Talho Aberto, — Table VIII. column 15) open-work, and covered, to a depth of several feet, the mouths of both adits in the valley. Lyon, Reports of the Imperial Brazilian Mining Association, iv. p. 36. On the 22nd of November, 1830, a mass of earth and stones some ten or twelve feet in thickness—loosened from the higher and steeper slopes by thirty-six hours of heavy and continuous rain—slid suddenly into the low grounds;— sweeping before it trees, underwood, and two cars in course of being loaded on the mountain;—burying heaps of ore, many surface-works, and one of the water¬ wheels ;—injuring several shallow parts of the mine; and filling the deeper . (levels) galleries. Skerrett, Jennings, Hambly, Prideaux, & Harris, Ibid , x. pp. 42,64. On the 8th of December, 1831, a hillock of ancient debris , which had been softened by the rain, slipped suddenly down one of the eastern glens; stopping one of the water-wheels, choking the adit , and covering two or three acres of the valley, some twelve or fifteen feet with stones, trees, brushwood, and mud; but, happily, neither touching the principal surface-works nor entering the mine. A yoke of oxen having become entangled, were saved with some difficulty, as most of the people had already left work.— Skerrett, Ibid, xn. p, 43 (Abstract). Notwithstanding much precaution, the (Regos) water-courses—which at Gongo Soco extend more than twenty miles—suffer great damage during the rains. Ibid, Passim. The (Termes fatale, L.) ants, which are exceedingly numerous, open from their large, hard, earthen nests, narrow underground passages, of great length, in all directions. These often penetrate and so weaken the banks that they give way; when the streams, as they escape, bear with them to the rivers quantities of earth and stones. In the (Campos) pastures near Gongo Soco a colony of ants had built them¬ selves nests, some three or four feet in breadth and height, and had covered them with waterproof clay. About one hundred yards off a beautiful garden, belonging to the Chief Commissioner, was so watered that each bed formed, as it were, a separate island. The intervening space,—though traversed by a rivulet —was, however, thoroughly tunnelled by these mischievous neighbours. They neither entered the houses, nor worked during the day; but—opening after sun¬ set the passages, perhaps previously, made beneath the water—they frequently stripped an entire bed of all vegetation, save the stems of herbs and the branches of trees, in a single night. This havoc, however, was not quite indiscriminate ; for they left cucumbers, lettuces, pine-apples, and sometimes orange and coffee trees uninjured; but invariably destroyed every rose-tree and cabbage within of Minas-Geraes, in Brazil 351 These, however, are often arrested in their descent; and of those which reach the grassy lowlands, small portions only find their way to the rivers. Where a want of vegetation subjects the rocks to direct atmospheric influence, # they are rapidly and con¬ tinually disintegrated.! The portions degraded, with the auriferous beds they contain, and such small quan¬ tities of ancient cascalho as yet remain within reach, are from time to time swept into the rivers by the rain. Very different quantities, however, fall within short distances. reach. On different occasions—smiths’ bellows were used for forcing the smoke of sulphur and charcoal into the holes;—for weeks in succession water flowed through the nests,—meanwhile the eggs were dug out and destroyed, by cart¬ loads at a time; these, and other, means, however, merely checked—but failed to extirpate—the enemy. * In the dry-season every available rill was required to drive the stamps at Gongo Soco from fifty-five to sixty-five blows per minute (Table IX. Note l). During the day, however, evaporation from the (Regos) water-courses (Ante, p. 350, Note *) caused them to work—at times as much as one blow per minute —more slowly than they worked at night. f Near Brumado the works of Captain Jose Alvarez, are carried on in a cleft opened—apparently by natural causes—some twenty feet deep, near the summit of a mountain of decomposed granite, which may be truly called auriferous ; * * * for specimens of the earth, from the roots of the grass to the bottom of the lavra , all contained gold.— Mawe, Travels in Brazil , p. 374. “ Chaque jour le Rhin travaille a modifier son lit en corrodant certaines parties “ de ses rives; de la la formation de ces nombreaux bancs de gravier et iles, “ entre lesquels il se partage. * * * “ Tout le lit est aurif&re, apeu d’exceptions pres; mais cet or, chaque fois qu’il “ est transports par l’eau avec les cailloux au milieu desquels il est dissemine, “ va se concentrer specialement dans certaines positions qu’il importe de savoir “ reconnaitre d priori. * * * “ Les bancs nommes Goldgrwide , auxquels l’orpailleur doit particulierement “ s’adresser, sont ceux formes a quelque distance a l’aval d’une rive ou d’une “ lie de gravier corrodee par le courant; ces bancs resultent par consequent d’un “ transport du gravier, tantot sur quelques metres seulement, tantot sur 1,000 “ ou 1,500 metres de distance. C’est dans une zone etroite qui termine les “ bancs vers l’amont, que pour abreger on peut appeler leur t£te, que se trouvent “ particulierement accumulSes les paillettes, presque toujours au milieu de gros ccc 352 W. J. Henwood, on the Detrital Gold Gongo Soco* at the foot of a high, wooded Serra, near a great tributary of the Rio Doce, and Morro Velho f in an equally mountainous, but an unwooded, region, of much the same elevation, on the upper waters of the Rio das Velhas, some twenty miles distant, afford example; for inches . three years’ observations show an average annual fall of .. 121 -08 at the former ;t whereas nine years’ ,, ,, „ but 68‘97 at the latter.J Great quantities of gravel, sand, and mud are also carried to the rivers by the water in which ore is treated at the mines. “cailloux; toutefois cette richesse exceptionnelle ne s’etend qu’a une faible “ profondeur qui ne d^passe guere 15 centimetres. * * * “ Les digues artificielles entre lesquelles coule le Rhin sur une partie de son “ cours, au-dessous de Kehl, sont entaillees par des coupures, ou passes, qui sont “ destinees a donner passage aux hautes eaux; afin qu’elles aillent deposer des “ ensablements au dela de ses digues. Les atterrissements ainsi formes derritSre “ les digues par un courant lateral renferment aussi des parties riches au milieu “ du gros gravier. * * * “ Les bancs qui se forment au milieu du fleuve loin le leur point de depart sont “ en general peu riches. “ Dans les bancs les plus pauvres, dont on essaye la teneur sur une grande “ nombre de points, on trouve cependant aussi, en dehors des positions qui vien- “ nent d’etre signalees, des zones etroites et allongees de gravier riche; * * * “ ainsi il n’est pas rare de rencontrer de ces zones riches au pied des talus ter- “ minaux qui limitent un banc a l’aval, * * * “ Jamais je n’ai trouve la moindre trace d’or dans le sable fin prive de cailloux “ que le Rhin depose encore journellement dans ses crues. On ne rencontre “ m£me dans ce sable fin que des traces de fer titane et du quarz rose, qui “ accompagne toujours l’or. “ Quelle que soit leur position dans la fleuve, les paillettes d'or sont associees “ a des cailloux, dont la grosseur est en general en rapport avec la dimension “ des paillettes qu’ils accompagnent. La residu du lavage contient toujours du “ fer titan6, dont la quantite est proportionnelle a la quantity d’or.” Daubree, Annales des Mines, 4me Serie, x. pp, 6, 13,14. * Ante, pp. 291—6. f Ibid, p. 184, X Ibid , p. 349, J of Minas- Gerties, in Brazil 353 The refuse of several open-works on the Serra of Antonio Pereira accumulates at the foot of the slope throughout the dry season : when—as in the Bhabur of Kumaon *—the water by which it is conveyed, sinks through the shingle; but—gliding along the rock beneath,—reappears at a lower level. During the rains, however, this deposit is swept down the valley ; where it has raised the bed of the brook,—a tributary of the Gualaxo,—at least ten feet within fifty years.f All stamped ore is carried from beneath the heads .— by water admitted on purpose—down long (Cano'ds) inclined-planes, on which cured-hides and strips of baize are carefully laid. In the upper of these, rough grains and threads of gold are entangled; whilst further and further down, ore—-more or less rich— * Ante, pp. 42—4. f Captain Joao Pereira de Azevedo, MSS. The refuse of several china-clay works encroach, in like manner, on the valley near St. Austell (1865). The head streams of the Fal flow through Tregoss moor, where there are many tin stream-works; from which great quantities of matter are constantly washing into the river, and are carried down into the creek below Tregoney. The navi¬ gation has been destroyed for more than two miles, and the injury is rapidly extending. * * * Restrongett creek formerly extended much farther up Carnon valley, than it now extends, but the upper part of the navigation has been choked by gravel and silt from the mines. * * * By the constant accession of such matter, the bed of the whole creek, except the anchorage in Restrongett pool, is now above the level of low-water at spring-tides.— Thomas, History of Falmouth, pp. 31, 48. About the middle of the last century * * * sand for manure was brought by barges as high as Dunstan’s mills [more than a mile above the present limit of navigation],— Francis, Gwennap, p. 8, Note. “ In 1851, West and South Caradon Mines paid a large compensation to the “ landowners in the lower part of the Seaton Valley, for injuries occasioned by ” sand and mud from the works.— Allen, History of Liskeard, p. 398, Note. 354 W. J. Henwood, on the Detrital Gold subsides, somewhat in the order of its specific gravity. # The portions escaping scarcely shew a trace of gold at first; but trituration by the rippling brooks f into which they fall,—separating light fragments of vein¬ stone ,—lays bare the richer particles enclosed ; within short distances, therefore, certain of the better parts are deposited £ in the beds and at the sides of streams ; whence they are sometimes gathered, and a second time submitted to like treatment. The ore which escaped from Gongo Soco accumu¬ lated at Taboleiro,' about a mile from the principal works; where—on being once more stamped and dressed \—it yielded, on an average, a (Troy) pound of gold per month. For more than thirty years some fifty-five thousand tons of stamped iron-ore and talcose mud were annually discharged from this mine into the Socorro river; yet Mandi || were caught in great * Table VII. Notes h — t; Table IX. Note m 1—6. f At Gongo Soco the horses and mules preferred the rill in which Jacotinga had been stamped, to water of greater purity. £ A small stream which rises amongst the hills south of Camborne, is—in various parts of its course to the sea near Gwithian—used for (dressing J washing the produce of Condurrow, Dolcoath, and Wheal Crofty; but from each mine it carries off, in suspension, small quantities of tin-ore, still adhering to its matrix. The separation, which stamping and other processes had failed to accomplish, is, however, gradually effected by the action of running water; minute portions of ore are therefore collected in lower parts of the stream, by appliances exactly similar to those which had been inefficient to arrest them above.— Captain Charles Thomas, MSS. § We have minutely examined the tank at Taboleiro, and find that the upper portions of its contents consist of fine Jacotinga, sand, and slime, the lower of rough Jacotinga only; the former we propose to pass over Concentration-strekes (Table IX, Note m —6), the latter to stamp; we expect this system will answer very well.— von Helmreichen, Harris, Collins, Blamey, & Pengilly, Reports of the Imperial Brazilian Mining Association, xxx. p. 87- || “ Mandi ,—one of the Siluridce, perhaps a species of Mystus; from a foot and of Minas-Geraes, in Brazil. 355 numbers. At Agoa Quente also, small Traira* * * * § throve in water which—reaching the adit at temperatures varying, in different parts of the mine, from 81°*9 to 96°*5f—was fouled with similar impurities. At Morro Velho , in like manner, the stamped-ore which passes from the Canoas in suspension is collected on the (Praia) margin of a neighbouring stream, where it is again stamped and conducted over hides and baize. From 1856 to 1863,—1,365*25 lbs. ( Troy ) of gold were here obtained,^ which, but for these re¬ peated processes, must have been lost. In the last twenty-seven years more than one million five hundred thousand tons of pyritous, argillaceous, and quartzose sand and slime have been washed from this mine into the Rio das Velhas ; nevertheless Surubim,^ weighing ten or twelve pounds, are still taken near Sahara. As the bed of every river is, with more or less regularity and abundance, replenished from each “ a half to two feet long, with no apparent scales, and long barbecels proceding “ backward from its mouth. It keeps near the bottom of the river, is taken “ by the hook, and considered one of the best fish it produces.” Gardner, Travels in Brazil , p. 416. * 11 Traira. —Also about two feet long and rather slender, it takes the bait “ and is much estemed.”— Ibid , p. 416. f Postea —Appendix. + Symons, Reports of the Saint John d'el Rey Company , xxvn. p. 40; xxviii. p. 47; xxix. p. 43; xxx. p. 43; xxxi. p. 48; xxxn. p. 60. Dietzsch, Ibid, xxxiii. p. 50; xxxiv. p. 49. § “ Surubim. —This fish, which is a species of sturgeon, often reaches the “ length of six feet. It is taken most commonly in nets, but sometimes also, u especially by the Indians, by being shot at with an arrow, to which a strong cord “ is attached. The flesh of this species dried, is that principally sold in the “ Sertao ” (high table-land); “ I have frequently tasted it, and found it excel- “ lent.” —Gardner, Travels in Brazil, p. 415, 356 W. J. Henwood, on the Detrital Gold formation within the district it drains; the metallic, as well as the earthy, portions of these deposits, in various streams,—and sometimes even in distant parts of the same stream,—present characteristic differences. Crystals, dendritic flakes, # thin scales, nuggets, threads, and grains of gold are thus mingled with the other ingredients; but the largest of them rarely exceed a quarter of an inch in diameter, and the smallest are microscopic, f Trifling quantities occur on the hard, gravelly, shallows, where a few spangles are now and then found and swallowed by water- fowl ; J but the greatest part is scattered through the sand and silt. The gravel and coarse sand, when collected, are * Rounded grains and nuggets are mixed—with crystals of gold at Ballarat,— with dendritic gold at Mount Alexander, — and with both at Me Ivor river Victoria), Australia.— Stephen, Quarterly Journal of the Geological Society of London , x. p. 306—8. f “ L’or ne se trouve jamais le gravier du Rhin en pepites ou en petits grains ; “ il est toujours sous forme de paillettes tres-minces, a contours arrondis, dont “ le diametre n’excede pas un millimetre ” (0*03937 inch) “ et est souvent “ beaucoup moindre; * * * La surface de ces paillettes examinee au micro- “ scope pr^sente une multitude de petites aspdrites assez regulieres. * * * Le “ poids moyen d’une paillette est de 0*0562 milligramme ” (0 000867 grain). Daubree, Annales des Mines , 4me Serie, x. p. 21. % The late Mr. Fitzpatrick of Gongo Soco presented me with a small quantity of quartzose and ferruginous gravel, mixed with minute scales—weighing some fifteen or twenty grains—of gold; which his cook had found in the gizzard of a Muscovy duck; brought, a few days previously, from Brumado on the Santa Barbara river. The crop of a second duck, from the same place, contained similar gravel but a smaller proportion of gold- Edinburgh Neio Phil. Journal, L. p. 62. “ The cook of a Government officer at Galle recently brought to him a ruby il about the size of a small pea, which he had taken from the crop of a fowl.” Emmerson Tennent, Ceylon, i. p. 34. of Minas Geraes, in Brazil . 357 stirred — until they become suspended — in small streams; which are passed over (Canoas) inclined- planes, laid with baize, as at the stamps* The richer and heavier parts,—subsiding first,—are then washed in the batba until the gold is separated from its earthy accompaniments. The fine sand and mud are treated in the batea only; the (Faiscador) washer standing—often nearly to his middle—in the stream, whilst he scrapes the ore from its bed. To protect himself from the sun and rain,—which occasionally alternate several times a day during the hot season,— he uses a coarsely platted covering of long grass; J which—reaching from head to waist—serves as both hood and cape. Great numbers of poor freemen earn a scanty liveli¬ hood § by thus separating the gold from the detritus; and many (Bogeiros) small farmers employ their slaves in the same manner, when field-work is slack. || The proportion of gold obtained, from the beds of * Mawe, Travels in Brazil, p. 266, von Spix und von Martius, Reise in Brasilien, i. p. 340. von Eschwege, Pluto Brasiliensis, p. 256. de Saint- Hilaire, Voyage dans les Provinces de Rio de Janeiro et de Minas Geraes , i. p. 250. Gardner, Travels in Brazil, p, 497. Ante, p. 353 : Tables — VII. Note k ; IX , Note m —3. f Mawe, Travels in Brazil, p. 109. von Spix und von Martius, Reise in Brasilien, I. p. 340. Gardner, Travels in Brazil, p. 510. Table IX. Note l. $ “ Les negres se preservent de la pluie avec des especes de manteaux assez “ pittoresques, faits avec les feuilles tres longues et fort seches d’une Graminee “ ou Cyperac6e, que l’on appelle capim mumbtca.” —de Saint-Hilaire, Second Voyage dans VInthieur du Brasil, I. p. 189. % Ante, pp. 224, 283, 301, || Ibid, p. 299. “ Slaves are allowed to work on their own account on Sundays and holidays.” Gardner, Travels in Brazil, p. 465. Ante, p, 301, Note f. 358 W. J. Henwood, on the Detrital Gold existing rivers, # has never been ascertained ; but in 1849 it was estimated that, on an average, each (Faiscador) washer collected from four to five (4*684) grains of gold; and thus earned about (one pataca — 320 reis) eight pence per day.f The ( Faiscador ) gold-washer pays no {dues) Royalty to the landowner. * After the ancient detritus of the Rhine had been abraded, transported, and redeposited by the stream, it yielded the undermentioned proportions of gold;— Varieties of (ore) sand. Proportions of gold. First quality . 0*000000562. Second „ . 0*000000243. Third ,, average wrought .. 0*000000132. Fourth ,, poorest „ 0*000000120. Fifth „ unwrought... 0*000000008. Daubree, Annales des Mines , 4me S6rie, x. pp. 16, 28. f In that year the gold of Antonio Pereiro (23 carats 3*5 grains fine) was sold at (3,500 reis per oitava of 55*33 grains ) £40 : 19 : 10 per lb. Troy. During 1814 the rivers of Minas Geraes afforded employment to 3876 freemen and) 1871 slaves } 5747 P ersons * oitavas lbs. per lb. who extracted ....(115,321*25) l,107*768of gold, worth(at£40 : 19 :10) about .£45,418 each (Faiscador workman there-f ( 20 . 06) 0 . 1927 fore obtained, on ' 99 99 [per ann. 7 : 18 : 0 an average ....) and reckoning 300 working days in the year. oitava [per day. „ ( 0*06) 3*7 grains „ , „ n 0 : 0 : GJ von Eschwege, Pluto Brasiliensis , Tabellarische Uebersicht alter Goldlavras jeden Districts in Minas Geraes , p. xxi. The Rhenish ( Orpailleur) gold-washer treats about (four cubic metres ,—one hundred and forty-one cubic feet) eleven tons and a quarter of sand; earning —according to the quality of the deposit he works—now and then from eight to twelve shillings, but seldom more than twenty, and sometimes less than ten, pence, per day. Some five hundred persons engage in this pursuit at intervals; but—as most of them are either husbandmen, boatmen, or fishermen, on oc¬ casion—the entire proceeds of their labour range only from (40,000 to 45,000 francs) sixteen to eighteen hundred pounds a year. Daubree, Annales des Mines , 4me Serie, x. pp. 12, 23, 24 (Abstract). Whitney, Metallic Wealth of the United States, p. 94. Ante, pp. 245—8, Notes. of Minas-Geraes , in Brazil . 359 The deep-yellow grains and microscopic crystals of gold* * * § ** collected in the Gualaxo, are akin to those of Antonio Pereira, f near the source of its principal tributary;—the paler flakes, small nuggets , and crys¬ talline granules found in the Peri^icaba have a family likeness—both in hue and in alloy—to the gold obtained—where its head-waters rise,—amongst the talcose and quartzose rocks of the Cara^a ; J—and the dark-coloured gold of the Socorro river—like that of Gongo Soco § in its vicinity, — is associated with copper, silver and palladium. But it is needless to lengthen this list; for the metallic as well as the earthy ingredients, in the bed of every river, resemble those of adjoining mountains. || Detrital-gold—like stream tin-ore,f-ho we ver, is always of better quality, ## and invariably fetches a higher price, than mine-gold of the same neighbourhood. * Henwood, Edinburgh New Phil . Journal , l. p. 63. f Ante, pp. 214, 304; Table X. column 17. t Ante , pp. 177, 181, 236, 241. § Ibid, p. 286 ; Tables ,— IX. column 49, X. column 17. || Ante, p. 355. H “Stream Tin —consists of detached fragments, or of crystals of tin.” Phillips, Mineralogy (3rd Edit.), p. 253. In “ an interesting group of fine crystals of gold, interlacing an hexagonal “ quartz-crystal ” from Me Ivor river (Australia), such of the edges of the gold “ and quartz crystals as have been exposed to the contact of rough bodies are “ rubbed and destroyed, whilst the edges of the crystals which have been pro- “ tected by surrounding crystals are as perfect and sharp as when formed by “ nature.”— Stephen, Quarterly Journal of the Geological Society, x. p. 307. ** “ The quality of the tin-ore found in stream-works is very much superior “ to that obtained from veins at small depths.” Henwood, Cormoall Geol. Trans,, iv. p. 65. The following analyses of detrital and mine gold from New Granada, are recorded by M. Boussingault. DDD 360 W. J. Henwood, on the Gold-Mines Although gold was obtained from this region in 1599,* and—if tradition be credited—for sometime bartered by the Indians f with the earlier settlers; it Localities. Detrita Propor Gold. il-gold. tions of Silver. Mine- Proporl Gold. gold. ions of Silver. Bucaramango .. 0*980 0 020 Giron . 0*919 0*081 Lavega ... 0*821 0*179 Ouijihrnlnmn ... 0*919 0*081 Mn.Ym.ntn .................... 0*744 0*256 Means. 0*907 0*093 0*831 0*169 Annales des Mines , 3me Serie, i. p. 446. “ On pourrait aussi admettre, au moins pour l’or natif du Chili, qu’en general “ at which time the decay of the mines became more and more rapid every year, “ the arrears had been allowed to accumulate, till, in 1790, they amounted to ** the tremendous sum of seven hundred arrobas ” (27,545 lbs.). Southey, Brazil , hi. p. 680. of Minas- Geraes, in Brazil. 367 lbs. Troy . Brought forward .• .. 1,404,967 Of the yield daring forty following years the Records of Government make but little mention ; and other sources of information are few. In 1814 the entire produce of Minas Geraes was.. (228,449 oitavas) 2,194*450 lbs; * but of this the mines gave only (113,127 ,, ) 1,086*687 ,, . * Soon afterwards, however, several of them became so prosperous f that they attracted the attention of foreign capitalists. In 1825 Gongo Soco —then one of the richest mines J — was bought by the Imperial Brazilian Mining Association; and, shortly more than a dozen others were wrought by aid of British money and skill. Many of these, unfortunate¬ ly, proved unproductive; and several were abandoned after brief—though costly—trials; so that at last Morro Velho alone was still worked by foreigners. From 1825 to 1860 the mines belonging to English Companies § yielded about........ 91,000 Forward. 1,495,967 * von Eschwege, Pluto Brasiliensis; Tabellarische Uebersicht alter Goldlavras jeden Districts in der Provinz Minas Geraes, in Jahre 1814, xxi. f Ante, p. 216, Notes f Table VIII. column 15. $ “ Within fifteen years a larger amount of Duty has been received from “ Gongo Soco, than in twice that time from all the Province beside.” Sen. Manoel Teixeira de Souza, Secretary of the Treasury at Ouro Preto (1844). lbs. § From 1825 to 1856 Gongo Soco yielded 34,528 of gold. it 1833 n 1846 Cocaes 99 557 » it 1835 99 1860 Morro Velho 99 51,631 »» it 1840 99 1844 Catta Branca 3,167 it it 1844 99 1846 Catta Preta 99 28 it it 1847 99 1853 Agoa Quente 9} 808 a Table IX. column 46. Ante, p. 247. Table VII. column 26. Ante, p. 179. 1leports of the Imperial Brazilian Mining Asso¬ ciation, XXXVII.—XLII. Ante , p. 235. Forward .. lbs. 90,719 ,, E E E 368 W. J. Henwood, on the Gold-Mines Of those wrought by native proprietaries, a few have been, at intervals, very rich ; * * * * § but in general their produce has materially declined, t In 1814 the rivers afforded (115,321*25 oitavas) 1,107*768 lbs. of gold; J but the gradual impoverishment of the mines whence their existing beds were in great measure de¬ rived^ and the gleaning to which they were continually subject,|| had so much diminished lbs. Brought forward .... 90,719 of gold. From 1820 to 1860 Antonio Pereira , S. Joao d'el Rey , S. Josi, Mocaubas, Candonga , S. Vicente , Morro das Almas, Caiaba , Emilia, and Conceigao , together, yielded about . 1,000 Total .... (say) .. 91,719lbs. Troy. * During the years 1852,-3,-4, seven mines in the Municipality of Itabira afforded (253,479*25 oitavas) 2434*900 lbs. of gold, which realized.(887,177,335ms) £99,807 : 9 : 0; at a cost of.( 97,928,266 „ ) 11,016 :18 : 8. Thus leaving a profit of.(789,249,069 „ ) £88,790 : 10 : 4 Extracto das informacoes prestadas pelas Camaras e outras Autoridades da Provincia (1855). f “ Marianna .—Informa u Camara que os moradores do Forquim applicao-se “ a agricultura * * * Este Districto esta muito decadente por faltar a minera- “» • • • • 050 99 quartzeau .. ,, .... 012 )} micacique .. >> .... 025 100 Claussen, Bulletins de V Academie Royale des Sciences de Bruxelles , viii.—I re Partie, p. 328. $ Henwood, Edinburgh New Phil . Journal , l. p, 62. lbs. Troy . i “ From 1849 to 1859 .. C the gold coined and recoined 1 (7,578,745 oitavas ) 72,800 G88 “ Daring the financial » | at the Mint in Rio de Janeiro > year 1858—9.j ( amounted to.) 1st Jan. to 1st July, 1860 ) 2,472-482 ) 124-877 ( 257,392 , about ( 13,000 , “ Much of this consisted of Sovreigns and other foreign money; but what part “ of the rest was obtained in the Country is unknown. 370 W. J. Henwood. Notices of Regarding the quantity of gold smuggled out of the Province during so long a period, it is manifestly impossible to offer even a plausible conjecture; but it is supposed to have been at least one-fifth of the whole produce.* * As the mines became less prosperous and foreign capital was gradually withdrawn, the inhabitants improved their roads, and occasionally substituted wheeled-carriages for beasts of burden. Landowners who in times past had found work for their people as gold-washers or as miners, now employed them as husbandmen or as herdsmen ; and from unfrequented districts, of which the produce had hitherto been sold at home for less than the cost of its conveyance to market, neighbouring towns were supplied with corn and cattle.f “ A considerable quantity of gold-dust, brought down by Muleteers and Shop- “ keepers, is absorbed by the Jewellers.” John Morgan, Esq., of the British Legation at Rio de Janeiro, MSS. (1860). * That one-fifth of all gold extracted from the Captaincy had been clandestinely exported, was considered a moderate computation.— Southey, Brazil , m. p. 820. * ■f “ Ate certo tempo eminentemente mineira e rica pela extracpao do ouro e do “ diamante, cujos jazigos marcavao o berpo e fixavao o assento de muitas povo- “ acoes importantes, hoje e de ha certo tempo, tornando-se muito contingente, e “ pouco lucrativa essa extracpao, esta industria tern definhado e sofrido progres- “ sivo abandono, dirigindo-se com preferencia a actividade aos habitantes da “ Provincia para a lavoura, e criacao que encontrao riquissimos recursos em seu u vasto e variado solo que ja lhe tern dado riquezas muito superiores as que lhe “ deu sua primeira industria, e por certo afianpao uma prosperidade mais segura “ e sempre erescente.”— Falla que a Assemblea Legislativa Provincial de Minas “ Geraes dirigio no acto da abertura da Sessao de 1859 o Dr. Joaquim Delfino Ribeiro da Luz, 1° Yiee-Presidente da mesma Provincia. Gold-Mines in Virginia . 371 Notices of Gold-Mines in Virginia. At considerable distances south-east of the Appala¬ chian chain,* * * § ** an approximately parallel band of slate,f —which, in various parts of its north-easterly and south-westerly range from Canada to Georgia and Alabama, consists of talc,J mica,§ chlorite,|| felspar,^ and siliceous matter in different proportions, — alternates, at intervals, with short and ill-defined beds of auriferous quartz/ft * Maclure, Transactions of the American Philosophical Society, i. n.s. p. 10, PL I. Rogers, American Journal of Science, i. Second Series, p. 474; Reports of the British Association, iv. (1834) p. 2. Lyell, Travels in North America , II. First Series, PI. I. Whitney, Metallic Wealth of the United States , p. 121. f Hitchcock, Address to the Association of American Geologists at Philadelphia f in 1841, p. 11. Whitney, Metallic Wealth of the United States, p. 122. $ Dickson, del Rio, Millington, and Clemson, Transactions of the Geological Society of Pennsylvania, i. pp. 20, 147, 308. Rogers, Geological Reconnoissance of Virginia (1836) p. 68. Ansted, Scenery, Science, and Art, p. 288. § Rogers, Geological Reconnoissance of Virginia, p. 71. Silliman, American Journal of Science, xxxn. p. 99. Whitney, Metallic Wealth of the United States , p. 128. || Rogers, Geological Reconnoissance of Virginia, p. 68. Clemson, Transactions of the Geological Society of Pennsylvania, I. p. 309. Whitney, Metallic Wealth of the United States, p. 122. Ansted, Scenery, Science, and Art, pp. 288—9. H Featherstonhaugh, Excursion through the Slave States, II. pp. 354—8. ** Rogers, Geological Reconnoissance of Virginia, p. 68; Reports on the Geological Survey of Virginia (1839), p. 47, (1840) p. 48. Whitney Metallic Wealth of the United States, p. 128. Ansted Scenery, Science, and Art, p. 289. ft Olmsted, American Journal of Science, ix. p. 5. Mitchell, Ibid, xm. p. 1. Dickson, del Rio, Millington, and Clemson, Transactions of the Geological Society of Pennsylvania,!. 16, 147, 157, 159, 308. Rogers, Geological Reconnoissance of Virginia, pp. 66—70. Silliman, Smith, and Maury, American Journal of Science, xxxn. pp. 98,130, 325. Rogers, Report on the Geological Survey of Virginia (1840), p. 49. Featherstonhaugh, Excursion through the Slave States, II. pp. 354—8. Mitchell, Map of the Gold-region of Virginia (Fredericksburg, 1849). Whitney, Metallic Wealth of the United States, p. 128. Ansted, Scenery, Science, and Art, pp. 283—93. Whitney, Metallic Wealth of the United States, pp. 114—34. Logan, Geological Survey of Caiiada, Report of Progress, 1850-1, p. 6. Mining and Smelting Magazine, v. p. 109. 372 W. J. Henwood, Notices of Of this formation no part has, hitherto, been more productive, than that which traverses Virginia. (a.) The Chancellor smile or Grasty gold-mines are situate some twenty-five miles west of Fredericksburg, in an undulating—rather than a hilly—part of Orange County; where ill-cultivated fields, and heaps of barren rubbish, are irregularly interspersed amongst copse- woods and forests.* The rocks, generally, bear 30°-40° E. of N.—W. of S.,f dip 70°-85° N.W., and consist, for the most part, of clay-slates, flecked here and there with chlorite and talc. Their prevailing hues are buff, bluish-grey, and brown; but yellowish and reddish shades are not un¬ common. Within short distances of the beds which yield gold they are frequently of thick lamellar struc¬ ture ; but elsewhere they are often fissile. At distant parts of the series, but on the same meridian, several parallel bands, strictly conform to the schistose structure of the adjoining rocks, but materially differ from them in composition. In width, they are seldom less than four, or more than thirty, feet. Their ingredients are, for the most part, quartz and slate;— which are often thoroughly transfused ; though masses indifferently of either, are sometimes imbedded in a matrix of the other; and at intervals they form thin, separate layers; occasionally, however, angular and * At and near this place the bloodiest battles of the war of secession were fought. t In 1840 the magnetic variation was about 1° E. Sabine, Phil. Trans., 1849; PI. XIV. Gold-Mines in Virginia. 373 vein-shaped bodies of translucent and milk-white quartz are enveloped in siliceous matter, tinged more or less with red or brown earthy iron ore.* Small quantities of auriferous iron-pyrites, oxydulated iron, and yellow copper-ore, beside grains and particles of gold in still smaller proportions, are irregularly scattered through the beds of ferruginous quartz; and, yet more sparingly, through the slates f which adjoin them, One of these deposits has been wrought to a depth of fifteen fathoms. Ore culled, in 1852, from the produce of earlier operations, yielded the undermentioned proportions of gold:— Nature of ore. Proportion of (unrefined) gold. % Quartz, mixed with earthy brown iron-ore . Slate, mixed with quartz, earthy red iron-ore, and iron pyrites .. ].. 000023214 § ).. 0’00004056‘ § * Ante, pp. 181—2, 301—2. t Ibid. pp. 178, 186, 299, 300,—1,-2,—4. + Johnson and Matthey, Prospectus of the Chancellorsville Mines (1854), p. 3. ^ From a similar formation at Walton , in Louisa County, some miles south¬ west of Grasty, the following proportions of gold were obtained:— Nature of ore. Proportion of unrefined gold. (1.) Quartz, slate, brown iron-ore, and iron-pyrites; from) n*nnmiqn^ which “ all the visible gold had been carefully picked.”.. $ *' * * (2.) Quartz, slate, and brown iron-ore; an average of the ) 0*00028571 general produce ...*•...... 5’*** ' (3.) “ Quartz, taken at random from the heap of ore ”. 0*00071429 (4.) Quartz, “ pieces selected on account of their showing ) 0*00467857 ‘‘ gold to the naked eye ” ... J Silliman, American Journal of Science , xxxii. pp. 109—115. 374 W. J. Hen wood. Notices of The different proportions of silver associated with the gold in various matrices are shown in the following columns. Proportions of Nature of matrix. Gold.* Silver* Totals. Quartz, mixed with earthy brown) . f 0-776 0-224 1 iron-ore .J Slate, mixed with quartz, earthy red iron-ore, and iron-pyrites.. At Grasty , therefore,—as well as at Morro Velho\ 0-767 0-233 T * Mitchell, Prospectus of the Chancellorsville Mines, p. 3. “ Silver is occasionally found in connexion with the gold.” Rogers, Geological Reconnoissance of Virginia (1836), p. 68. f At Morro Velho , certain poorer and lighter kinds of selected ore, which the stamps-water (Table VII. Note i) washes off the Canoas and deposits on the (Praia) margin of a neighbouring river (Ante , p. 355), are there collected and again stamped , with slightly auriferous (“ killas ”) slate and other ingredients of inferior quality. But as the gold they afford is less (fine) pure than that con¬ tained in the richer ore, the two are reduced separately. The first two of the following analyses were made by Messrs. Johnson and Matthey after the last had been already printed (Ante, p. 334, Note ft). Metal obtained from the richer ores. Metal obtained from inferior ores Ckillas) slate. do (2.) (3.) Gold . 0-8083 .. .... 0*7910 .. .... 0*7499 Silver. 0 1850 .. .... 0-1865 .. .... 0-1793 Lead ... 0-0010 .. . .. 0-0090 .. .... 0-0180 Bismuth. 0 0020 .. .... 0-0020 .. .... 0-0135 Copper ... 0-0008 .. .... 0-0015 .. .... 00045 Antimony .. 0-0007 .. .... 0*0055 .. .... 0*0030 Arsenic ... 0'0022 .. _ 0-0030 .. .... 00105 Iron .. • • .... 0-0010 .. .... 0*0195 Mercury (traces) and loss.. * " • • .... 0*0005 .. .... 0*0018 1* 1* 1* John Hockin, Esq., Managing Director of the Saint Johnd’el Rey Company, MSS. Gold-Mines in Virginia . 375 and Gongo Soco *—the more largely the matrix is impregnated the greater is the (fineness) purity of the (crude) gold. ( b .) At Woodville, some three miles north-east of Grasty , the yellowish buff-coloured, thin-lamellar, talc-slate, which ranges 15°—20° E. of N.—W. of S., and dips 65°—75° W.; is conformably interlaid by two auriferous beds, about six fathoms apart. To a depth of thirteen fathoms, one averages about fifteen, the other perhaps seventeen, feet; at intervals, however, portions of both are merely a few inches wide. Like the corresponding bands at Grasty , they consist in great measure of quartz f and slate; often largely interspersed and deeply tinged with earthy brown iron- ore, but sometimes thinly sprinkled with iron-pyrites. “ It has been proved, by repeated experiments during the year, that—owing, “ probably, to a larger amount of silver,—the precious metal contained in the “ killas is, in quality, four carats inferior to that obtained from the (pyrites) ore.” Dietzsch, Reports of the Saint John cVel Rey Company, xxxv. p. 52. * Gongo Soco, Table IX., columns 2—6, 46—7. Depths, Workpeople. Gold. fms. Europeans Free Brazilians Totals. lbs. (Troy) extracted. Purity ( Toca ) fineness of 41* and Slaves. 198 578 776 2,988-456 21 carats 0-7 grains. 70- — — 685 514-502 20 „ - t “ The material of the [gold] veins is a variegated quartz, sometimes trans- “ lucent, at others opaque. It is generally of cellular structure, fractures with- “ out much difficulty, and in many instances contains a considerable quantity of “ water. Its surface, recently exposed, displays a variety of tints of brown, “ purple, and yellow, of such peculiar aspect as to resemble a thin lacquer spread “ unequally over the rock. The cavities are often filled with a bright yellow “ ochre, or hydrated peroxide of iron, which generally contains gold in a state “ of minute division. Sulphuret of iron (pyrites) is another accompanying “ mineral, which in many mines occurs in considerable quantities.” Rogers, Geological Reconnoissance of Virginia, p. 67. Featherstonhaugh, Excursion through the Slave States, ii. p. 355. Ante, p. 322. F F F 376 W. J. Henwood. Notices of Although no part is, perhaps, absolutely barren,* * * § most of the gold is disseminated either in the earthy brown iron-ore, or—within short distances of certain short joints and drusy cavities—in the quartz* (c.) At Whitehall , in the county of Spotsylvania, gold is likewise scantily strown through a similar matrix of quartz, slate, and earthy brown iron-ore; and rich granules are—like the native silver of Tre - hisken-green —here and there encased in small masses of galena.J Trifling quantities of black tellurium also occur in the quartz,§ and sometimes encrust the gold. ( d .) At the Buckingham (Hesse's and JEldridge’s) mines, near Maysville in the county of Buckingham, a rather fissile and somewhat contorted clay-slate,|| of homogeneous texture and leaden hue,—the lowest rock observed in that neighbourhood,—is succeeded by a narrow band of whitish quartzose mica-slate,fre- * “ Besides the auriferous veins of the region in which gold occurs, there exist “ many other veins of quartz agreeing with those which have been found produc- “ tive in nearly all particulars, save that of containing a valuable proportion of “ the precious metal. It is probable that none of these veins are entirely desti- “ tute of gold, and in many instances no doubt the prosecution of the vein would 4 ‘ lead to the discovery at other points of it, of an ore sufficiently rich to reward “ the labour of extraction. Indeed, it must be looked upon as probable, that “ the auriferous character, more or less, pervades the quartz-veins generally. “ * * * The striking similarity in the character of them all, and the obvious “ contemporaneousness of their origin , would seem to give great plausibility to “ this opinion.”— Rogers, Geological Reconnoissance of Virginia , p. 70. f Ante, p. 120, Note. X Rogers, Geological Reconnoissance of Virginia, p. 68. § Henwood, Cornwall Geol. Trans., vn. p. 229. (Whitney’s) Metallic Wealth of the United States, p. 128. || Rogers, Geological Reconnoissance of Virginia, p. 71. Reports on the Geolo¬ gical Survey of Virginia, 1839, p. 47; 1840, p. 49. Henwood, Mining Journal, 29th January, 1853 ; (Whitney’s) Metallic Wealth of the United States , p. 128. IT “ Rogers, Geological Reconnoissance of Virginia , p. 72; Reports on the Geological Survey of Virginia , 1839, p. 46; 1840, p. 48. Henwood, Metallic Wealth of the United States, p. 128, Gold-Mines in Virginia . 377 quently interspersed with talc; the auriferous deposit,* * * § which succeeds, is overlaid by thin lamellar greenish- white chloritic talc-slate,f now and then flecked with mica. The series, generally, ranges 20°—30° E. of N.—W. of S. and dips 40°—50° S.E.j: The metalliferous bed §—conforming to the dissimi¬ lar flexures of the rocks on opposite sides,—varies in width, from three to twenty feet on the north-east, but from four to five only towards the south-west. The north-eastern portions consist, near the surface, of granular, massive, and cellular quartz; sometimes im¬ bedded in, but frequently mingled with, earthy brown iron-ore. Traces of galena occur at intervals; and small drusy cavities often afford crystals of the phos¬ phate of lead, and of selenite. The quartzose parts contain bodies of friable iron-pyrites; of which the most deeply seated are the largest and most numerous. * Henwood, Mining Journal, 29th January, 1833; (Whitney’s) Metallic Wealth of the United States, p. 128. Ansted, Scenery, Science, and Art, p. 288. f Rogers, Geological Reconnoissance of Virginia, p. 72; Reports of the Geolo¬ gical Survey of Virginia, 1840, p. 48. Henwood, Metallic Wealth of the United States, p. 128. Ansted, Scenery, Science, and Art, p. 288. t Partz, American Mining Magazine, n. p. 379. Henwood, Metallic Wealth of the United States, p. 128. Ansted, Scenery, Science and Art, p. 288. § At the “ Buckingham Mines and those of Mr. Eldridge, the ore * * * is “ an auriferous pyrites, occurring in a whitish or white schist. The vein is “ worked at a depth of 90 feet, or thereabouts, but has been proved to 160, and “ remains uniform. It yields about (0-00000919 its weight) 6 dwts. of gold to 11 the ton, and some silver. Of this there seems an indefinite quantity; and “ from the Buckingham mine there were obtained about 1500 ounces of “ gold in the course of last year. The expense of getting and reducing is “ estimated at 15 shillings per ton, but there is much loss. About 20 tons of ore “ per day are crushed and amalgamated on an average, the daily yield lately “ being (0*00000995 its weight) 130 dwts. * * * About 80 feet down from the 378 W. J. Henwood. Notices of These—like the productive deposits at Morro Velho* * * * § Cronebanef and Connorree\ —enclose isolated masses of copper-pyrites; § invested occasionally with copper- glance, but more generally with earthy black copper- ore. The south-western portions include many un¬ connected, angular blocks of slate; || of all which the compositions resemble, and the planes of structure conform to, the compositions and structures of the rocks in their respective neighbourhoods. Except in this particular, and that massive quartz is more abundant, the south-western parts differ but little from the north¬ eastern. “ surface threads of copper ore were found, consisting of copper pyrites mingled “ with the iron pyrites which forms the staple. These have gradually increased, “ but at present there seems little chance of any very important result for copper. tc * * * Little oxide of iron appears here at any considerable depth below the >> The food of each slave cost therefore (less than ) n n , four pence) ) ” ” W. M. Moseley, Esq., MSS. From 1840 to 1848 the hire of slaves in Brazil averaged (one hundred milreis) £11 : 5 : 0 a year each. (Table IX. Note c.) ,, — ,, their rations consisted, however, of fresh beef, bacon, beans, Indian-corn meal, and vegetables; beside coffee, sugar, and rum (Ante, p. 292, Note). In Brazil, therefore, the slave-owner derived less profit, but the slaves were better fed, than in Virginia. Gold-Mines in Virginia 383 These results show the proportion of gold to have been larger in the shallower and narrower, than in the deeper, wider, and flatter* parts of the principal bed. Selected samples contained (3 oz. 16 dwts: f) 0*035659 ; but ores from a depth of fifteen fathoms in the grains per ton Garnett Mine yielded, on an average, (242-36) 0*000015 their weight of gold. Moseley ,, „ (194*87) 0-000012 „ Choice specimens of ore from both mines afforded gold 21 carats 1*375 grain fine.f lbs. dollars. The 108 49 (Troy) of gold obtained in 1851 realized (24,015-45) £5003 2 6 „ cost of extraction^ .amounted to (12,562-00) 2617 1 8 ,, year’s operations, therefore, gave .. a profit of 11,453-45 £2,286 0 10 The beds of many streams have afforded large * Thomas, Report on a Survey of the Mining District from Chacewater to Camborne, p. 20. Ilenwood, Cornwall Geol. Trans. , v. p. 231. Ante , pp. 82-3. + Johnson & Matthey, Prospectus of the Garnett # Moseley Gold Mining Company , p. 2. t “ Expense of working the Garnett and Moseley mines during the year 1851.” Salaries of two Superintendents. Wages of two Miners. „ two Engineers and their two Assistants .... Food of Miners and Engineers. 360 Hire of sixty Slaves. at 90 dollars a year each.. 5,400 10,920 lbs. of Bacon. ,, 8 cents per lb. 262 barrels of Indian-corn. „ 3 dollars per barrel.... Clothing for Slaves . 600 Keep of Cattle... 430 Iron, Steel, Rope, Powder, Safety-fuse, &c. 2,100 700 dollars. 600 99 700 19 360 99 5,400 99 880 99 792 99 600 99 430 99 2,100 99 12,562 dollars. W. M. Moseley, Esq., MSS. G G G 384 W. J. Henwood, on the quantities of detrital-gold ;* but, with few exceptions,')' the masses have been small. * “ In the county of Louisa great success attended the operations of some “ persons who had unexpectedly come upon an extraordinary rich bed of auriferous “ gravel, from which in six days they extracted native gold, in grains, of the value “ of ten thousand dollars. * * * Soon after this discovery, the vein from whence “ it was derived was also found, consisting of a pale porous quartz, thickly studded “ with knobs and laminae of native gold, and upon comparing specimens of it “ with ” that obtained from the gravel “ I found that many of the pepitas , or “ knobs of gold, corresponded in form, although the alluvial gold was rounded “ and worn by the action of the water.” Featherstonhaugh, Excursion through the Slave States, n. p. 353. “ Nothing is more common in these deposits than to find masses of quartz “ with small lumps of native gold imbedded in them, resembling in every par- “ ticular, others which are taken from veins now in place, the heaviest masses “ being always found nearest to the auriferous strata, and the particles of gold- u dust at the greatest distance from them.”— Ibid, p. 351. “ Washings were formerly carried on successfully in a small gully running “through the (Waller) estate; and on searching for the veins whence the “ auriferous sands had been removed, they were found distinctly marked close “ to the surface.”— Ansted, Scenery, Science , and Art, p. 284. “ In the alluvial deposits gold is sometimes very much water-worn and in “ comminuted particles and sometimes in nuggets of a considerable size, rough “ and angular with quartz still adhering to them as if they had not been carried “ far from the vein whence they were detached. * * * “ Silver is always associated with the gold [of Canada] to the extent of from “ 10 to 15 per cent.” Dawson, Report on the Canadian Gold Fields, p. 80. (1865. Printed by order of the Legislative Assembly.) f A nugget of nearly nine pounds, beside many masses of a few ounces each, “ were mixed with grains of gold in the bed of a rivulet immediately south of “ the Garnett and Moseley mines. Major Miller, Superintendent of the Moseley mine, MSS. “ A subterranean Indian village was discovered in Nacooche valley, Georgia, “ by gold miners, in excavating a canal for the purpose of washing gold. The “ depth to which it is covered, varies from seven to nine feet; some of the houses “ are imbedded in a stratum of rich auriferous gravel. They are 34 in number, “ built of logs from six to ten inches in diameter, and from ten to twelve feet in “ length. The walls are from three to six feet in height, forming a continuous “ line or street of 300 feet. The logs are hewed and notched as at the present “ day. The land beneath which they were found was covered, on its first settle- “ ment by the whites, with a heavy growth of timber.” Dickson, Trans . Geol. Society of Pennsylvania, i. p. 25. / / Native Copper of Lake Superior 385 On the Native Copper of Lake Superior. The rich metalliferous series immediately south of Lake Superior, overlies three large ranges, and several smaller tracts, of granite.* The first reaches the shore near Presqu’ isle and Huron river ;-the second extends from Chocolate river beyond the Machi-gamig ;—the * “ Granite forms, for the most part, the rim of the Lake Superior basin. * * * It appears in low, undulating hills, nowhere attaining a greater elevation than (1,873 feet above the lake) 2,500 feet above the ocean. On the northern shore, it is more widely distributed than on the southern; but its geographical boun¬ daries have been imperfectly determined. * * * “ Granite forms the coast between Presqu’ isle and Granite Point. Proceeding westwardly, it expands rapidly until it attains a width of twenty-five miles. * * * The extreme length of this granite axis is sixty miles, and its culminating points rise 1,200 feet above the lake. “ Another granite boss rises to the south of that above described, and ranges in a nearly parallel direction for about thirty-six miles. The interval between them is from twelve to fifteen miles in width. * * * “ Farther west, another granite belt starts from the head waters of the Onto¬ nagon river, and thence extends to the western limits of the district. * * * It is probable that this belt is a continuation of that first described, but we have not been able to trace the continuity. * * * “ There are, also, numerous insulated patches of granite scattered through the crystalline schists. * * * “ The Huron, Granite, and Middle islands, as well as several islets off Presqu’ isle, belong to the same formation- “ The granite, for the most part, forms numerous parallel ridges, bearing east and west. “ Several systems of joints cut the rock into tabular plates, which will materi¬ ally aid the quarry-man in his labours.” Felspar and quartz are always the principal—and sometimes they are the only —components; but, in general, either mica, hornblende, or chlorite is also present. “ The granite of Middle island is intersected by powerful dykes of greenstone, some of which are ninety feet in width, and we counted no less than six within the distance of forty rods. They cut the greenstone in remarkably straight lines, leaving clean, smooth edges. * * * In the smaller dykes, the greenstone is very compact and fine grained; but in the larger, whilst it exhibits this texture near the edges, towards the centre it becomes highly crystalline. * * * There 386 W. J. Henwood, on the third comprises the sources of the Ontonagon and the Montreal. The granite is generally succeeded by gneiss,* but are two systems of dykes; one set bears nearly east and west, while the other bears north-east and south-west; these, in their turn are intersected by veins of quartz. In section I., along the east boundary of township 49, range 27, “ a ridge of granite * * * bearing N. 20° E. * * * is traversed by powerful dykes of green¬ stone in a direction parallel to its prolongation. There are also seen numerous granite veins, seldom exceeding eight inches in width, ramifying through the granite, and occasionally through the greenstone. Mica is more abundantly dis¬ seminated through these veins than in the adjoining walls. * * * “ At the junction of the granite with the azoic slates on the southern side, the relation of the former to the latter is clearly seen. The slaty rocks are traversed by * * * veins of granite, which gradually increase in number and dimensions as we approach the granitic nucleus. On an almost vertical wall of rock, about forty feet in height, near the south-east corner of section 25 (town¬ ship 47, range 27,1 the granite is seen penetrating the hornblende-slate like an immense wedge, and shooting out in ramifying branches. * * * “ The granite which forms the axis between the river systems of the two lakes [Superior and Michigan] * * * has disturbed the upper beds of slates, while the lower beds of the Potsdam sandstone rest undisturbed around it. * * * “ Of the whole district the granitic region possesses the least economical value. There appear to be no metallic veins worthy of exploration, and from the broken and rugged character of the surface, it is ill adapted to agricultural purposes.” * * * Foster & Whitney, Report on the Geology of the Lake Superior Land District; Part n. (1851) pp. 38—48 (Abridged). Geological Map of the Lake Superior Land District , in the State of Michigan ; prepared pursuant to an Act of Congress ; by J. W. Foster and J. D. Whitney, United States Geologists. * Between township 49 range 32 and Keweenaw bay the rocks succeed in the following order:— “1. Granite. * * * “ 2. Gneiss, with a large amount of mica. “ 3. Compact hornblende, with silex in places predominating. “4. Chloritic, argillaceous, and silicious slates. “ On the southern flank the following was the order of succession observed. “1. Granite. “ 2. Quartz and feldspar passing into granular quartz. “ 3. Compact hornblende, traversed by numerous joints. “ 4. Magnetic and specular oxide of iron, with thin laminae of white, granular quartz. * *- * “ On approaching section 31, township 46, range 29 * * * closely grained Native Copper of Lake Superior. 387 sometimes by hornblendic-rocks; which occasionally alternate with, but are more frequently followed by, quartzose, micaceous, talcose, or chloritic slates; and these pass gradually into clay-slate, which assumes here and there an arenaceous character.* * In many of the upper strata lime f is an abundant ingredient. and firmly cemented hornblende rocks appear * * * in dark green masses. * * * On the adjoining section south the granite appears in low, rounded outcrops * * * flanked on the south by hornblende, presenting the same lithological character as that on the north. * *- * “ Near the south boundary of township 42, range 31, the granite pierces through the incumbent strata, *-*•#. On either side corresponding alter¬ nations of hornblende and mica slate are observed, * * which are found to graduate into chlorite and argillaceous slates. * * * At portage No. 2 the chlorite slate contains numerous vesicles filled with calc spar. *- * * Asso¬ ciated with them are seams of quartz ranging and dipping with the enclosing rocks. They often contain scapolite, and the sulphuret of iron and copper. The metallic contents, however, of these seams were regarded as worthless. * * * “ The granite rises in low ridges from amidst the talcose, hornblende, and chlorite slates, in townships 41, 42, 43, and 44, through the whole district west¬ ward to 45. Ht Ht Ht “ Granite is the predominating rock below the southern boundary of township 47, and is associated with a hornblende-rock, which sometimes assumes a slaty structure.” Foster & Whitney, Report on the Geology of the Lake Superior Land District, Part n. (1851) pp. 20—57 (Abridged). * “ In higher parts of the series, the argillaceous slates become interstratified with argillaceous sandstones.”— Ibid, p. 12. f “ Calcareous bands occasionally occur of sufficient purity to be called lime¬ stone. Hi Ht Hi “ In the north-east quarter of section 2, township 47, range 25, a band of slaty limestone, somewhat silicious, is seen beneath the quartz. Hi Hi Hi In the northern part of section 3, the quartz is interstratified with another band of limestone. Hi Hi Hi “ In section 31, township 48, range 25, another band of compact limestone was traced westward, through sections 33 and 36. Hi Ht Hi It is less silicious than that before described, variously coloured, white, ash-grey, and flesh-red, and variously veined with tints of a deeper hue. It calcines readily into lime, and affords beautiful ornamental materials.” Ibid, pp. 12, 15,16. 388 W. J. Henwood, on the Dykes and beds of hornblendic and felspathic rocks occur throughout the system ; * but they are numerous in the neighbourhood of certain rich deposits^ of iron- * Ante , pp. 385—6, Notes *. f “ The very interesting deposits of iron ores on and near Lake Superior, % % # are in the azoic, and they form literally mountain masses * * Ht The distance of these deposits from the Lake, at the nearest point is about twelve miles Ht * * . From this point, the ores of iron are found at intervals in a belt of slates from six to twenty-five miles wide, extending for a distance of one hundred and fifty miles or more westward into the State of Wisconsin.” Whitnby, Metallic Wealth of the United States, p. 477. “ The principal deposits of specular and magnetic ore [in township 47, range 26,] are arranged in a metalliferous belt, bearing nearly east and west. * * % A small stream which is one of the sources of the Escanaba river is at one point precipitated over a ledge of ore, * * * which consists of a peroxide of iron, mixed with considerable silicious matter, and seems to exhibit indistinct lines of bedding which dip at a high angle, and are intersected, at nearly right angles, by joints which cut the mass into large tabular blocks. * # * “ Along the line between sections 32 and 33, near the junction of the azoic slates with the granite, the relations of the iron to the slaty and quartzose rocks are well displayed. * % * On the north side of a ravine, which extends for a considerable distance east and west, # % % quartzose bands, composed of fine grains of silicious matter, impregnated with peroxide of iron, with occasional wide bands of pure ore, alternate with a hornblende rock, having a schistose structure, and equally charged with ferruginous matter. # * * On the south side of the ravine * 4 k # a succession of trapean and granitic belts, crossed by numerous veins of igneous rock, is presented. Here, however, the rock is no longer charged with iron. “ In township 47, range 27, * * % the ferruginous band, wrought by the Jackson Company, form a ridge about a thousand feet in width, and from a few feet to fifty in height, above the level of the surrounding country, and can be traced almost continuously across the section in an easterly and westerly direc¬ tion. On the northern side of the belt, the ore is compact, and of great purity; near the centre it exhibits a banded structure, while to the south, it passes again into the compact variety. % # # This deposit is bounded on the south by highly crystalline hornblende and felspar rock, and on the north by slaty chlo¬ ride, beds, # # Numerous veins of quartz cut the great mass of ore, and contain specular oxide in large brilliant plates. * * * “ In sections 10 and 11 west the deposits # * # are, in fact, unrivalled in the abundance and almost absolute purity of the ore. The purest ore occurs in a ridge which extends across the line between these two sections. It rises with precipitous walls to the height of at least fifty feet. * * * The purest portions are a very compact and fine grained specular ore, having an imperfect slaty structure, and traversed by joints, like the slates in the neighbourhood. Through Native Copper of Lake Superior . 389 ore; of which many portions—now largely wrought,* this fine-grained base are scattered numerous minute crystals of the magnetic oxide. In other places, the ore is almost entirely made up of an aggregate of crystals of the magnetic oxide, sometimes very minute, and rarely larger than a pin’s head. * * * Metallic matter has penetrated the adjoining slaty rocks, and filled them with crystals of magnetic oxide and occasional streaks and bands of fine-grained peroxide of iron. * * Ht “ Farther south another deposit on a scale of still greater magnitude, though not equal in purity to the ore last described, is known as the Cleveland location. It rises * * * in a ridge one hundred and eighty feet above the stream at its base, one hundred and fifty-two feet above the drift terrace * * near its northern slope ; and forms the culminating point between the two lakes. # * * It is made up of alternate bands of pure fine-grained peroxide of iron and of jaspery ore. The thickness of the bands varies from that of a sheet of paper to one-fourth of an inch. They are not arranged in a constant position, with regard to the general disposition of the mass; but are twisted and contorted in every variety of form and outline; the curvatures are, however, mostly on a very small scale, the radius of curvature in the concentrically folded layers never being as great as one foot in length. * >k * The width of this deposit of ore cannot be less, at its base, than one thousand feet, and it may be traced for considerably over a mile in length. * * * “ The largest mass [of ore] observed by us in township 46, ranges 29 and 30, occurs on the left bank of the Machi-gamig. It here rises in a nearly vertical cliff to the height of one hundred and thirteen feet, and is somewhat variable in purity. For the most part, it has a slaty cleavage, and on close inspection, is observed to be composed of alternating bands of micaceous specular iron and quartz, tinged red by the peroxide of iron; but there are occasional belts of granular texture, and apparently of greater purity. These laminae are nearly vertical, exhibiting few contortions, and range with so much uniformity, that the observer would be inclined to refer both the slates and the iron to a common origin.” * # * Foster & Whitney, Report on the Geology of the Lake Superior Land District , Part n. pp. 50—7 (Abridged). * il The iron ore of Lake Superior * % % can be quarried—for it is not mining—and placed upon the railway carriages, ready for transportation, for less than one dollar (four shillings and two pence) per ton. The average value of the ore is from 60 to 70 per cent. It is safe to say that this portion of Michigan can produce all the iron-ore that is necessary to supply the world with iron for ages, without sensibly diminishing the quantity, or enhancing the value thereof.” The first shipment of ore made in 1855, was . 1,457 tons. in 1856 there were shipped. 11,597 „ 1857 „ .. 26,184 „ 1858 „ .. 30,327 „ 1859 „ .. 80,000 „ 1860 „ .. 150,263 „ 1861—3 „ .. 299,583 „ 1864 „ .. 235,123 „ Total in ten years 834,534 tons. 390 W. J. Henwood, on the —resemble, as well in structure as in composition, the Itabirite* and Jacotinga \ of Brazil. Of other ores and metals, however, the traces are few.J “ The pig-iron produced in 1858 was. 2,000 tons. 1859 „ . 6,000 „ 1860 „ . 6,500 „ Total in three years. 14,500 tons. In 1860 “ the average value of the ore on the docks ready for shipment, was about three dollars [twelve shillings and sixpence] per gross ton, and of pig iron from twenty ,to twenty-five dollars [four pounds three shillings and four pence to five pounds four shillings and two pence] per ton.” The manufacture of pig-iron “ commenced at the Pioneer Works, near the Jackson Mine, in 1858, # % % but the Collinsville, Porestville, Morgan, Northern, and Greenwood furnaces have been since erected. # # # “ The blasts are driven, in some cases by water—which is abundant and can be used during the severest winters, but in some cases by steam, the gas from the furnace been taken as fuel. The usual pressure is 2 lbs. per square inch, and the temperature 620° F. “ Charcoal [the only combustible used in the furnace') is made almost entirely in kilns 25 to 30 feet in diameter, and 25 to 30 feet high, shaped like a straw bee-hive, and capable of burning 30 or 40 cords in 17 days; 20 to 25 of these kilns are required for each furnace, and they are scattered through the forest in the neighbourhood of the heavy timber. Maple and birch, with some hemlock, are the woods charred; 2£ cords are found to produce 100 bushels. Charcoal is now being delivered at 11 cents [five pence halfpenny] per bushel, by contract. It requires 125 bushels of charcoal to reduce one ton of iron, and the furnaces produce from 10 to 18 tons in 24 hours. The flux used is a limestone found near the railroad, and which does not cost over 35 cents [one shilling and five pence-halfpenny] per ton of iron. # # # The cost of making iron is now (1865) about thirty dollars [six pounds and five shillings] per ton. * % % “ Land, from which may be cut an average of 50 cords (6,400 cubic feet) of wood per acre, may be bought at from two dollars and a half to four dollars [ten shillings and five pence to sixteen shillings and eight pence] per acre in hundreds of places along the shores of the lakes. Two competing lines of rail¬ way already lead from the mines to the lakes.” Legislature of Michigan, 1861; Report of the Joint Committee of the Senate and House of Representatives ; No. xix. p. 6. Lamborn, Mining Journal (5th Aug., 1865) xxxv. p. 509 (Abridged). * Ante, pp. 211, 214, 219,221, 224, 226, 227, 237, 242, 244, 248—9, 251, 298. f Ibid, pp. 212, 214, 219, 223—4, 227, 229, 230—6, 242, 245, 251—81; Fig. 20. X “ The results of our enquiries have led us to believe, that, aside from iron, the metallic products of the azoic series will prove of little value. We have Native Copper of Lake Superior. 391 Veins of granite penetrate the lower hornblendie rocks, but do not extend to the calcareo-siliceous slates. The nearly horizontal beds of sandstone, # —which occur in the plains and on the smaller hills, but never not seen a regular well-defined vein of any extent, with well-defined wall-rocks and gangues differing from the enclosing mass. There are fissures and irregular rents which contain metallic products, such as copper and iron pyrites, magnetic oxide of iron [galena, black oxide of manganese], &c.; but they differ from productive lodes in their want of continuity and parallelism.” Foster & Whitney, Report on the Geology of the Lake Superior Land District, Part n. p. 82. * The “ sandstone appears along nearly the entire southern shore of the Lake, from Sant Ste. Marie to Fond du Lac, its continuity being interrupted in only a few points, where the trappean or granitic ranges have been for a short distance denuded of the sedimentary beds which were originally deposited upon them. The general trend of the southern shore is east and west, but at a nearly equal distance from each end of the Lake, the regularity of its outline is broken by a projecting point of land, which extends for sixty or seventy miles in a north-east direction, gradually curving round to the east. This is Point Keweenaw, the locality where, by the present generation, the copper-bearing veins were first opened and worked.”— Whitney, Metallic Wealth of the United States , p. 251. Geological Map of the Lake Superior Land District; by J. W. Foster & J. D. Whitney. Rivot, Annales des Mines, 5me Serie, vn. p. 229. “ The sandstones repose nearly horizontally on the basset edges of the slates, or occupy the depressions in the granite.” # % * * But “ while the granite ranges attain in places an elevation of 1,200 feet above the lake, the sandstones, except in the vicinity of the trap, do not reach higher than 350 feet, # % % . Consequently, the granites and slates rise up like islands through this great waste of sandstone.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , n. pp. 110, 114, 122. “ Wherever the sandstone comes in contact with the granite, or prior-formed schists, it is observed to have a slight inclination away from the older rocks, rarely exceeding 8° or 10°.”— Ibid, p. 136. “ At a distance from all igneous action where the sandstone has been regularly deposited and not subjected to any disturbing influences, it appears to be made up almost entirely of angular fragments of nearly pure quartz, which are hardly held together by any visible cement. The grains are generally of the size of a pin’s head, and often present crystalline facets. * % * In general, however, it is somewhat coloured by a trace of iron. In the vicinity of the trappean rocks, it becomes highly charged with iron and calcareous matter.” Ibid , pp. 190—1. Near Portage lake “ some of the strata consist of silex, with thin plates of mica interspersed, whilst others contain portions of alumine, coloured red by oxide of H II H 392 W. J. Hen wood, on the reach the higher ranges,—un con form ably overlie the lower, and abut on the upper, slates; though here and there they touch the granite. Quartz—sometimes the only,—is always a principal component; felspar is generally abundant; and, near the granite, mica is also a common ingredient. Thin layers of conglomerate, containing nodules of quartz and small angular masses of granite, occur at intervals ; and calcareous matter is largely diffused through upper members of the series. Many portions are whitish or greyish ; but yellow and brown are the prevailing hues. The position # and organic contents of this deposit iron. # % # At Iron river, and at several other points, the sandstone is very fissile and of dark colour, resembling a slaty rock. % % % On Torch river the sandstone # # # consists of yellow or red grains, without any visible cement, enclosing quartzose pebbles and patches of dove-coloured clay.” Foster & Whitney, Report on the Geology of the Lake Superior Land District , I. pp. 110—15. “ In general this sandstone is composed of fine grains of quartz and felspar, together with rounded particles of primitive and trap rocks ; and it is important to remark that no fragment of the Silurian fossiliferous limestones, known to occur to the northward, was ever noticed in its conglomerates. Grains of mica are sometimes abundant, especially near its contact with the granite.” Bayfield, Quarterly Journal of the Geological Society , i. p. 453. Rivot, Annctles des Mines, 5me Serie, vn. p. 229. * “ There seems no reason to think that this formation can be more recent than the old red sandstone; and. when it is considered that it appears in the St. Mary’s at low levels, forming nearly horizontal strata at the bottom of Lake George, whilst the horizontal fossiliferous limestone of Sugar Island and St. Joseph’s rises into higher ridges, so as to make it highly probable that the sand¬ stone occupies the inferior position; and that, moreover, a sandstone is known very generally to underlie transition limestone in Canada and the United States : when all this is taken into account it is, perhaps, not unlikely that the sandstone in question may belong to the Silurian rather than the Devonian period.” Bayfield, Quarterly Journal of the Geological Society of London , i. p. 453. “ The almost uninterrupted continuity with which this rock can be traced even from its eastern extension through Canada and along the northern shore of Lake Huron to the St. Mary’s river, and thence westerly, leaves no doubt as to its true position and identity in age with the Potsdam sandstone of New York. Native Copper of Lake Superior . 393 show that it belongs to the Potsdam sandstone, the lowest fossiliferous # group of North America. If we were at a loss in thus tracing it continuously, we have still the evidence of the succeeding fossiliferous strata, which show, conclusively, the same re¬ lations to this sandstone as they do to its equivalent in New York.” Foster & Whitney, Report on the Geology of the Lake Superior Land District, n. p. 133. “ The evidence afforded by the facts collected by my friend and associate Mr. Murray (published in our Report of Progress for 1847—8), on the Grand Manitoulin, La Cloche, and other islands [in Lake Huron] Hi Hi % is clear, satisfactory, and indisputably conclusive. On these islands, the Potsdam sand¬ stone, the Trenton limestone, the Utica slates, and the Loraine shales, successive formations in the lowest fossiliferous group of North America, were each, in one place or other, found Hi Ht Hi resting in unconformable repose, in a nearly hori¬ zontal position upon the tilted beds and undulating surface of the quartz rock and its accompanying strata. % Ht # The conclusive evidence thus given of the Huron [formations] would appear to settle that of the Lake Superior rocks in the position given to them by Dr. Houghton, the late State Geologist of Michigan, as beneath the lowest known American fossiliferous deposits; and in this sequence those of the Huron, if not those of Superior, would appear to be contemporaneous with the Cambrian series of the British Isles.” Logan, Report of the British Association for 1851, Part n. pp. 60—1. Bigsby, Geol. Trans . i. n.s. p. 193. * u The Trilobite occurs on the Menomonee, while we have the Lingula every¬ where.”— Foster & Whitney, Report of the Geology of the Lake Superior Land District , n. p. 131. “In 1845 Mr. Forrest. Shepherd brought from Tequamenon Bay, two speci¬ mens of sandstone containing Lingulae. The rock was composed of rounded grains of quartz, cemented by calcareous matter. Ht Hi Hi In a small fragment were parts of five separated valves of Lingula, two of them nearly entire. The form of the entire shell is round-obovate, and more elongated in proportion to its breadth than the ordinary specimens of L. prima from the same sandstone in New York. Nevertheless I am not prepared to describe it as a distinct species. Ht Hi % “ Specimens from the Escanaba river, in the lower part of the calciferous sandstone, resemble, in all their important characters, those from Tequamenon Bay. From the comparison of specimens, I am inclined to unite all these in one species. Hi Hi Hi The calcareous beds on the St. Croix river are crowded with the valves of this species, and another so closely resembling the L. antiqua , that I have not found characters to warrant the separation. “ From the number of individuals occurring in the small fragment, from Tequamenon Bay, it is evident that, at that point the rock was highly charged with these forms of organic life, % % Hi “ In connection with the Lingulae on the Escanaba river, I collected a number 394 W. J. Henwood, on the Keweenaw Point—an irregular obtuse-angled tri¬ angle, of which the sides measure respectively about ninety, sixty-five, and fifty miles, # —consists, for the most part, of sandstone, intersected by ranges of trap, which are often, but not always, associated with con- glomerates.f The first band extends from the north¬ eastern headland to Sand bay, a distance of eighteen miles, but it rarely exceeds five furlongs in breadth.^ of obscurely pointed triangular bodies, like those described in the Palaeontology of New York as Thecce? % % # “ In the Lake Superior district, the only fossils seen in the Potsdam sandstone, in addition to these just described, are fragments of one or more species of Trilobites, which were found on the Menomonee river. These have the charac¬ ters of the Ogygia or Brontes; but those in possession of the survey, are too imperfect to admit of satisfactory determination. A farther examination of the prolongation of this sandstone across the interval between Lake Michigan and the Mississippi and St. Croix rivers, has resulted in satisfying us that the sand¬ stones of the two termini are identical in age, and the Trilobites specifically the same.”— Hall (Foster & Whitney’s), Report on the Geology of the Lake Superior Land District , pp. 203—5. Bigsby, Quarterly Journal of the Geological Society of London, xiv. pp. 338-9, 434—5; xv. pp. 279—80. * “ On nomme pointe de Keweenaw la langue de terre qui s’avanee vers le milieu de la cote meridionale du lac, en formant une courbe dont la convexite est tournee vers le nord.”— Hivot, Annales des Mines , 5me Serie, vii. p. 206. f “ At the head of Keweenaw Point the trappean rocks are associated with conglomerates.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 59. Geological Map of the Lake Superior Land District. J“The outer belt of trap, occupying the extreme northern portion of Ke¬ weenaw Point, is less than a mile in width, and preserves a great degree of uniformity throughout its entire course. * * * * From the extremity of Keweenaw Point, it extends westerly for about eighteen miles in a curvilinear direction, and passes into the lake at the eastern point of Sandy bay. Through¬ out most of this distance it is protected from the action of the surf by a thick belt of conglomerate, but at several points the water has broken through this sea-wall and excavated spacious harbors in the igneous belt. Copper, Agate, Grand Marais, and Eagle Harbors are included in this belt, and owe their origin to a common cause.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 60. Native Copper of Lake Superior. 395 The second, or principal, band, however, traverses the entire length of the promontory, and, there, varies from less than a mile to more than four miles in width ; but in neighbouring portions of the Upper Peninsula [of Michigan], as well as Wisconsin, it is still wider.* * * § As the central differ from the outer portions of this formation; these—which also present some diversities of composition—are commonly particularized as the northern and southern trap-ranges.]' Near the ex¬ tremity of Keweenaw Point both ranges are slightly convex towards the north, but on the whole they bear nearly east and west; further inland, however, the principal range assumes, gradually, a north-easterly and south-westerly strike; J but in the Peninsula— once more deflected, though in an opposite direction—* it trends 15°—25° north of east and south of west.§ * “ A trap range starts from the head of Keweenaw point and runs west twenty miles; then curving to the south-west, crosses Portage lake near its head, and the Ontonagon river twelve miles from its mouth, and is thence prolonged into Wisconsin. Its length is more than one hundred and fifty miles; its width from one to twelve.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , I. p. 34. f Ibid, pp. 61—4. X “ On tracing into the interior the ranges which approach the Lake at the extremity of Keweenaw Point, they are found to extend in a general south¬ westerly direction along the whole line of the Lake, at a few miles from it.” Whitney, Metallic Wealth of the United States , p. 252. “ La direction est a peu pres E.— O. aupres de Copper-Harbor; elle tourne un peu vers le sud a l’extremite de la pointe de Keweenaw, et vers l’ouest elle devient progressivement N.—E, a S.—0. % % % Aupres du lac Portage, cette direction est N. 55° E. a S. 35° O., et plus loin, vers l’Ontonagon, elle est notablement differente, N. 65° E. a S. 65° W.” Rivot, Annales des Mines, 5me Serie, vn. pp. 210, 215. § In 1847 the magnetic variation in the Upper Peninsula of Michigan was 5° 35' E. —Whittlesey (Foster & Whitney’s), Report on the Geology of the Lake Superior Land District , n. p. 346. 396 W. J. IIenwood, on the Throughout this tortuous course, however, it maintains a general parallelism, as well to the beds of sandstone on either side, as to the coast.* * * § ' On opposite sides of the crystalline rock,f which occurs in the principal range, the beds of trap and conglomerate, together with the sandstones adjoining them, incline opposite¬ ly the northern and north-western portions, towards the north and north-west,§—the southern and south¬ eastern towards the south and south-east.|| The central crystalline mass, which consists of greenstone, is rarely interlaid by other rocks; on both sides, however, the trap-rocks frequently alter¬ nate with broad bands and lenticular bodies of * Foster & Whitney, Geological Map of the Lake Superior Land District. Ilivot, Annales des Mine s, 5me Serie, vn. PI. VII. f “ La chaine % % Ht est composee de trapp crystallin, porphyritique et sy^nitique, dispose par bandes mal definies et qui paraissent paralleles a la direction generate de tousles terrains.” Rivot, Annales des Mines, 5me Serie, vii. p. 208. J Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 69, Fig. 5. Rivot, Annales des Mines, 5me Serie, vii. PI. VIII. Figs. 2, 4. § Foster & Whitney, Report on the Geology of the Lake Superior Land District, i- p. 63, Fig. 4. “ Au nord, on rencontre d’abord des bandes de trapp plongeant vers le nord et versle nord-ouest, ensuite des couches et des bancs de conglomdrat, de trapp, de gres, et enfin des gres pareils a ceux du nord, et presentant, comme eux, une inclinaison decroissante quand on les observe en des points plus eloignes de Faxe du soulevement.”— Rivot, Annales des Mines, 5me Serie, vn. p. 208. || “ Au sud # H: * le gres s’appuie sur le trapp et plonge vers le sud sous un angle assez fort, mais qui devient de plus en plus faible, amesure que la distance au trapp est plus grande.”— Ibid, p. 207. “ Le versant meridional plonge vers le sud et vers le sud-est, sous un angle assez variable, mais compris en general entre 35° et 55°; le versant septentrional presente l’inclinaison inverse vers le nord et nord-ouest, sous un angle de 30° a 35°. Plus l’ouest l’inclinaison est plus grande; et dans la region d’Ontonagon elle atteint 55°.”— Ibid, p. 208. U “ In the central portion of the range % % * beds of conglomerate, of very inconsiderable thickness, occur between heavy masses of trappean rock. As we Native Copper of Lake Superior . 397 conglomerate.* In the Keweenaw district thick beds recede % % % in either direction, we find that the belts of trap become thinner, the conglomerate predominates, but gradually disappears, and is succeeded by sandstone.”— Whitney, Metallic Wealth of the United States, p. 253. ** North of the Little Montreal river four alternations of trap and conglomerate were observed.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 62. “ Near Copper Falls mine # * % there are not less than five repetitions of [coarse] sandstone and trap within the distance of 2000 feet.”— Ibid , p. 63. “ Sur les plans de la mine de Copperfalls [Pointe de Keweenaid] % % # les epaisseurs horizontales des bancs et des couches de trapp, de conglomerat et de gres, sont les suivantes. Greenstone . 500-00 metres 273-3 fms Trapp compacte, grenu, amygdaloide . 2,100-00 99 1,148-3 99 Conglomerat .. 3*50 99 1-9 99 Amygdaloide . 26-50 19 14-5 99 Conglomerat et gres . 32-60 99 17-8 » Trapp en grande parte amygdaloide.. 130-00 99 72-1 99 Conglomerat et gres . 13-00 99 71 99 Amygdaloide .. 10-50 99 5-7 99 Gres ... 8-25 99 4-5 99 Amygdaloide . 110-00 99 60-1 99 Conglomerat et gres . 133 00 99 72-7 99 Amygdaloide . 58 00 31-7 99 Grande zone de conglomerat et gres.. Amygdaloide . 1,660 00 „ jusqu’ au lac.” 907*7 99 Rivot, Annales des Mines, 5me Serie, vii. pp. 214—15. “ Aupres du lac Portage * # % au sud, le trapp crystallin et porphyritique passe presque immediatement sous les conglomerats et sous les gres ; au nord, li est recouvert par des bancs successifs de trapp, compacte, grenu, amygdaloide, epidotique, separes les uns des autres par des lits tres-minces ou par des couches de conglomerats et de grks.”— Ibid, p. 215. “ In township 50, range 39, the trap is flanked on the north by a belt of con¬ glomerate, which occupies a width of one-fourth of a mile. Numerous alter¬ nating bands of igneous and aqueous rocks are observed.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , I. p. 73. “ Au sud-ouest du lac Portage et jusque bien au dela de la riviere Ontonagon, la disposition generale des terrains est en grande partie la meme qu’ a la Pointe de Keweenaw.”— Rivot, Annales des Mines , 5me S6rie, vn. p. 215. Logan, Report of the British Association (1851), Part n. p, 60. * “ Interstratified with this [the northern trap]-belt, throughout its entire range, v r e observe numerous lenticular masses of conglomerate, which appear to affect the courses of the veins, as well as their productiveness.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 62, 398 W. J. Henwood, on the of chlorite # sometimes divide the sandstones and con¬ glomerates from the trap for several miles; but near Ontonagon layers of epidotef prevail. The anticlinal axis, of crystalline greenstone, is flanked, on both sides, by trap-rocks which-—whether of granular, compact, or crystalline structure,—often interlie, but sometimes enclose, bodies of amygdaloid and conglomerate.^ * From the cliffs of hornblende and labradorite north of the Montreal river “ a band of conglomerate from twenty to fifty feet in thickness can be traced almost uninterruptedly for a distance of twenty-five miles. At the Cliff and North American mines a bed of chlorite rock occupies a corresponding position.” Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 62 (Abridged). A belt of chlorite, which expands to about 150 feet in thickness, between the trap and sandstone near Lac la Belle Ht Hi Ht “ is found to continue almost uninterruptedly to Portage lake; always preserving the same relation to the rocks above and below it. Such occurrences are not uncommon in this district.” Ibid, pp. 65—6 (Abridged). “ A red and green chlorite rock, fissile, but not stratified, enveloping masses of amygdaloid, is seen Ht Hi Hi on an affluent of the Torch river.”— Ibid , p. 67. f “ In township 50, range 50, west of the Ontonagon Hi Hi Ht a vein-like mass of epidote can be traced from the bottom to the top of a hill, and for a consider¬ able distance along the course of the formation; Ht Hi Ht It has no perceptible walls, and on either side it may be seen graduating into the trap.”— Ibid, p. 74. “ On section 35, is a high cliff made up of irregular alternating bands of amygdaloidal trap and amygdaloidal epidote.”— Ibid, p. 75. X “ The usual mineral components of the trap are labradorite and augite, with a smaller proportion of various other minerals, amongst which magnetic oxide of iron, chlorite, and epidote are the most abundant, with smaller quan¬ tities of the zeolitic minerals and calc-spar, as accidental ingredients. The feldspathic and augitic portions are usually finely granular, and form a compact homogeneous paste, in which the others are embedded; and the recognized differences in the characters of the different trappean beds do not seem to depend so much on chemical composition as on mechanical structure; as they seem in most cases to contain the same or very similar mineralogical components,in very different conditions of mechanical aggregation.” Whitney, Metallic Wealth of the United States, p. 253. “ Le trapp forme des bancs tres-diffdrents les unes des autres par leur aspect et par leur structure. La roche parait etre un melange plus ou moins intime Native Copper of Lake Superior . 399 The central portions of both ranges consist, mostly, of labradorite and hornblende; yet chlorite is also plentiful; and epidote—though of merely local occur¬ rence—is often abundant. The structure, ordinarily, is crystalline; but distinct crystals of either principal ingredient are frequently imbedded, in masses of the other, and in mixtures of the rest. # d’amphibole hornblende et de feldspath labrador : ces mindraux sont parfois en cristaux distincts, parfois en grains imperceptibles.” Rivot, Annales des Mines, 5me Serie, vn. p. 225. * Le greenstone est un trapp a texture cristalline, contenant beaucoup d’am¬ phibole et de chlorite; la couleur de la roche est plus ou moins foncee, suivant la proportion assez variable du feldspath.”— Ibid , p. 228. “ The summit of the Bohemian mountain & H: * consists of chlorite and feldspar of a highly crystalline texture. % * # Beds [of trap] are found dipping from it like the strata of detrital rocks.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 139. “ South of the Phoenix mine the feldspar predominates over the hornblende, giving the rock a light color. % % # The Albion range is capped with this rock, which appears in abrupt precipices two or three hundred feet in height. At the Cliff mine, the upper portion of the precipice is composed of dark crystalline greenstone—the hornblende largely predominating, which exhibits a mottled or varioloid appearance. At the Albion mine the feldspar again predominates, and the rock becomes in some degree porphyritic.— Ibid, pp. 64, 140. “In a dark crystalline greenstone from the summit of the ridge at the Cliff mine, three distinct minerals were recognized ; one is nearly colorless, or slightly tinged with green, and appears to be feldspathic, another is of a dark-green color, and resembles chlorite, while the third is apparently pyroxene or hornblende. Occasional crystals of magnetic iron occur. “ Its analysis as a whole gave Silica. 50-20 Alumina .. 15-43 Protoxide of iron .... 13-79 Time ........ ...... 5*47 Magnesia. 8-62 Soda ... * 4-75 Water . 1-74 100. ”— Ibid, II. pp. 87—8. “ At the Adventure mine the rock is a hard, crystalline, greenstone, somewhat porphyritic, traversed by occasional strings and veins of calc-spar and epidote.” Ibid, I. p. 141. Ill 400 W. J. Hen wood, on the In composition the trap-rocks differ but little from the greenstones; except that chlorite may occur in larger, and hornblende in smaller, proportions ; # cal¬ careous-spar and oxydulated iron, however, appear in * “ At the Northwest mine in the same belt of trap in which are contained the Cliff and North American mines % Hi H: the rock is a dark gray compact trap, occasionally amygdaloidal.— Foster & Whitney, Report on the Geology of the Lake Superior Land District, I. p. 135. “ In township 56, range 32 Hi Hi Hi the trap consists of a reddish and greenish chlorite rock, with imbedded amygdaloid.”— Ibid, p. 67. “ The only variety of trappean rock occurring in the Keweenaw Point range, in which the ingredients are distinctly visible, Hi $ % we find to be made up of a light-red felspathic portion, having the character of labradorite, of a dark- green foliated mineral, which is probably pyroxene, chlorite and magnetic iron.” Ibid, ii. p. 90. “ At the Quincy mine Hi Ht Hi the rock consists of a dark-brown chlorite trap, with beds of amygdaloid. Between the junction of these rocks native copper is observed in sheets.”— Ibid, I. p. 65. “ Between Portage lake and the Fire-Steel river Ht Hi Hi the following varieties may be recognized;— “ Compact-trap —varying in color and texture, and occasionally taking into its composition a large proportion of chlorite, and a greenish magnesian mineral. Some varieties are exceedingly fine-grained and close in their texture Hi % * ; others contain a very large percentage of magnetic oxide of iron. Ht Ht Ht The fluctuations of the needle often indicate the presence of the trappean rocks where they are effectually concealed by detritus and soil. Ht Hi % “ Porphyritic trap. The base of this rock consists of fine-grained trap, through which are diffused long and distinct crystals of white felspar. Ht Hi Hi “ Epidote trap occurs at many points especially in the vicinity of the Ontona¬ gon river, occupying a space of several miles in length. The compact trap often passes gradually into it, the epidote replacing the hornblende. Seams of quartz and calc-spar containing copper are accompanied by epidote, which graduates on either side into compact trap.”— Ibid, pp. 69, 70 (Abridged). “ At the Minnesota mine Hi Hi Hi the rock is a dark gray, mottled trap of a granular texture, with occasional almond-shaped cavities throughout it. It breaks into rhomboidal blocks, and readily yields under the drill. Its constitu¬ ents are hornblende, feldspar, and chlorite.”— Ibid, p. 134. “ La chlorite et le fer oxydule entrent presque toujours en notable proportion dans la composition du trapp, et dans les cavites on trouve assez frequemment des cristaux tres-beaux de prehnite, d’analcime et d’epidote. “ La chlorite est souvent en proportion tcllement forte, que le trapp parait etre up melange de feldspath et de chlorite, renfermant tres-peu d’amphibole.” Bivot, Annales des Mines , 5me S6rie, yii, p. 225. Native Copper of Lake Superior . 401 notable quantities ; # whilst epidote,—perhaps, associ¬ ated with augite,f—exists, at intervals only, as before. Some portions are compact, others granular ; £ but certain peculiarities of composition and structure, characterize each of the, rather ill-defined, beds § in this part of the system. The compact varieties, how¬ ever, exhibit now and then traces of crystallization; || but the granular layers often enclose,^ though some¬ times they pass into, 5 ** amygdaloid. Of this important * “ Le fer oxydule est presque toujours en petits cristaux discernables, quelque- fois cependant on ne peut le distinguer a la vue simple; mais sa presence est toujours accusee par l’action energetique produite sur l’aiguille aimantee. Hf % % “ L’epidote yerte plus ou moins melangee de quartz et de calcaire, se presente en masses considerables entre les bancs de trapp et penetre a une assez grande distance dans la roche amygdaloide. # % % “ Les cristaux definis d’epidote, de prehnite, d’analcime, etc., sont en relation avec les filons qui traversent le trapp ; ils ont ete rencontres plus frequemment a la pointe de Keweenaw que partout ailleurs.” Ibid, pp. 225—6. f“ We may consider it to be demonstrated tliataugite is formed whenever the process of cooling, and consequently of crystallization, is rapid ; and hornblende when it is conducted more slowly.”— Penny Cyclopcedia , in. (Augite), p. 85. % “ La structure des bancs de trapp presente de nombreuses variet^s.—Certaines bancs sont compactes, tres-durs et tres-charges d’amphibole; d’autres ont une texture grenue et contiennent beaucoup de feldspath, visible en cristaux blancs et roses ; ils sont aussi durs que les premiers et ne sont pas consideres comme exer^ant une bonne influence sur la richesse des filons.” Rivot, Annales des Mines, 5me Serie, vn. p. 226. § “ The contour of the bedded trap is very different from that of the unbedded trap.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, i, p. 64. || “A l’estle trapp cristallin * * * § ** % % est remplac6 par le trapp compacte.” Rivot, Annales des Mines , 5me Serie, vii. p. 209. IT “ Between Portage lake and the Montreal river # % % the amygdaloid is found irregularly scattered through the trap, but by no means so abundantly as west of the Ontonagon river.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 69. ** , ° bal • ~ ^ jS 5 | ft , S 1 °.‘s 1 1 m • 1 oo £ ° «k, o o c& oCG o? •&. yf 05 lo t— ■£ §3 & c O II? Ill ^ $ |.2 S 1 1 ^ 1 1 1 n •£ S u o ° . .S HQ 1 ® S, p. q | *N JO *AV # *S JO *a oOS — - Ai •& s -a's ii? i ? i I i 31 # ° ° - ^ £ § g v, K> SS , *A\'N s *a*s —*Ai JO *JSI S -a JO *s o 08 ^ g a 1 ' ! ' ' ' ling - - rf1 * C5 «S S? *AV Jo ’M S -a JO ‘S o08—o5I ^ ^ 1^0 °<5 . «o ^ . . , £ e ^ | § I JO o08 —‘M'S V '3.‘K * 0-07 * 0-14 0-24 n of the itney’s). 'essrs. Fo States, p was 5° 3 M'S % ‘a'M —*s j° m # ’n J 0 ’a 0 oe .2 f 3 ^ ^ ,ii iii |5f|? to S ^ t-i *S JO 'AV $ 'K JO -a o 08— 0 9t 0-07 0 18 0-14 0*24 * [ill (Fost >bser vatic alth of th s Superio , Note §. *S JO 'AV Q ‘K JO -a o9I—'S % ’M , o , i ^ 1 ++ §^ > 3 co 1 ^ ° 11 *? £.3 Hp, o o o ca •o a 2 <» •sopoj pnu ‘s^uiop ‘oSani-dcij, jo 7 Trap-range.. < Joints. Lodes . f Trap-range.. < Joints. ( Lodes . e results are deduc ; Mr. Whitney (Met magnetic variation ii. p. 346. Ant Nature of rock. Trap .. 1 Trap .. §Thes 760-4); || The D istrict 406 W. J. Henwood, on the . Owing to flexures of the principal trap-range, continuous portions in the neighbouring metal¬ liferous districts differ in direction * * * § somewhat more than ...22°. Meanwhile the lodes which traverse it at Keweenaw Point, vary in strike f from those which interlie it at Ontonagon, no less than .... 66°. At Keweenaw Point the angles included $ by the lodes and trap-rocks ° average about $ * ^ • Near Ontonagon „ § ,, „ 17°. * Foster & Whitney, Geological Map of the Lake Superior Land District. Whitney, Metallic Wealth of the United States, p. 252. Rivot, Annales des Mines, 5me Serie, vii. pp. 210, 215. Ante , p. 395. f The directions of the lodes in different parts of Cornwall and Devon, average—Saint Just... 35° N. of W. Saint Ives. 8° N. of W. Marazion . 1° S. of W. Gwinear, &c. 2° N. of W. Helston. 16° S. of W. Camborne. 20° S. of W. Redruth, Gwennap, and St. Agnes.. 22° S. of W. Saint Austell . 13° S. of W. Tavistock, &c. 9° S. of W. Mean .. 4° S. of W. Henwood, Cornwall Geol. Trans , v. p. 250. $ “ On Keweenaw Point one system of veins is well defined. Their bearing is north of west—the mean of several observations giving north 211 west. So true is this, that no permanently productive vein has been discovered thus far which varied 15° from this course, which is at nearly right angles to the formation.”— Foster & Whitney, Geological Report on the Lake Superior Land District , i. p. 167. “ Dans la region qui s’etend depuis l’extremite orientale de la Pointe jusqu’a la mine Albion, les filons transversaux sont extremement nombreux, leur dis¬ tance ordinaire parait comprise entre 200 et 600 metres, et tous sont h peu pres perpendiculaires a la direction du trapp : quelques-uns paraissent faire exception et couper les bancs sous un angle plus ou moins aigu ; mais en les etudiant avec attention, on peut reconnaitre qu’ils sont des veines detachees d’un filon princi¬ pal ou qu’ils ne s’etendent en diagonale qu’entre deux filons normaux.” Rivot, Annales des Mines, 5me Serie, vii. p. 249. § “ In the Ontonagon region * * * the veins run with the formation instead ■of cutting it at right angles, like those of Keweenaw Point.”— Foster & Whitney, Geological Report on the Lake Superior Land District, i. p. 168. ■“ The mode of occurrence of the cupriferous deposits of the Ontonagon Native Copper of Lake Superior . 407 All lodes exhibit many flexures;—as well vertical as horizontal; * * and in some instances they have different bearings')' in the same neighbourhoods. The following columns show the extreme and average dips of lodes having different directions.^ region differs materially from that exhibited by the veins of Keweenaw Point. They are characterized by a constant parallelism with the line of strike of the formation.”— Whitney, Metallic Wealth of the United States, p. 286. “ Tons les gisements explores jusqu’a present [dans le contree d’Ontonagon], sont dans le trapp, et sont paralleles, en direction, aux terrains.” Rivot, Annales des Mines , 5me Serie, vn. p. 267. * “ At the Cliff mine belts of rock form parts of great cnrves, not sensibly differing from straight lines in short distances, but whose divergence must be quite perceptible in an extent of 500 feet. Whitney, Metallic Wealth of the United States , p. 277. f At Lac la Belle mine two sets of veins have been observed—one bearing north 26£° west, which appear to be the main ones, and another bearing north 80° east.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 139, 148—9. At Copper Falls “ several veins are nearly parallel with each other, their course being north 22° to 2 5° west. They have, in almost every case, been traced across the whole width of the belt of trap north of the greenstone, a distance of more than a mile. % % * Two of these—the Copper Falls and Hill—veins only have been worked to any extent. ^ “ In this mine a remarkable feature has been discovered, which is unlike any¬ thing yet noticed on Point Keweenaw. This is the occurrence of a metalliferous bed included in the formation, and parallel with it. This stratum, which has been intersected in the works on both lodes, is about 100 feet thick ; and a fissure * * Ht between it and the overlying bed,—a bluish granular trap,—is filled with veinstone. This east and west vein is distinctly worked on the surface at the Copper Falls mine, where it contains small bunches of copper. The bed under¬ lying it % # # is of a brownish color, quite soft, and everywhere filled with copper.”— Whitney, Metallic Wealth of the United States , pp. 264—5. Rivot, Annales des Mines, 5me Serie, vn. pp. 265, 297—304. J Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. pp. 127—151; hi. pp. 760—4. Whitney, Metallic Wealth of the United States, pp. 262—301. Rivot, Annales des Mines, 5me S£rie, vn. pp. 245—326. Ante, p. 405, Note §. K K K 408 W. J. Henwood, on the Dips. N-- | N.E. S N.E.— \ E. S E.— S.E. S.E.— S. s.— s.w s.w. w. W.— I N.W. S N.W. ) —N. * ! Extremes.. Means .. N.- > N.E. \ N.E.— > E. \ E— > S.E. * S.E.— > S. J S.~ 7 S.W. J S.W.- ) W. s W.~ l N.W. ] N.W. > -N. \ Extremes.. Means .. t - N. to N.E.— S. to S.W. G.* S.* M.* Directions. _A_ 88 c 88 c 85° 85° 79° 79 c 42° 42 c N.E. to E.— S.W. to W. G. 84 c 84 c 70 c .70° s. M. E. to S.E,— W. to N.W. G. KEWEENAW. 55" f 55°t 82° 82° 80 c 80° ONTONAGON, 70° 42° 70° 42 c 55° 55° G5° G5 C 23° 23° M. 81 °t 32 ft 81° 48 c 48 c S.E. to S.— N.W. to N. G. 86 ° 85 c 8G C s. 60° 65° 60° M. 77°$ 77°§ 77° Dips. Extremes G. 82° 86 ° 88 ° 85° 88 ° G5° S5° 70° 85° s. 80° 60° 79° 65° 55° 23° 42° 42° 23° CO a ci Q> 81° 77°§ 84° 82ft 77°§ • • 55° t 77 o 48° 70° 55° 56° * g., s., m., —Greatest,—smallest,—mean. f Single observations, % Lodes having similar directions, but opposite dips. § >, 77 77 Native Copper of Lake Superior . 409 The lodes of Keweenaw Point have, therefore, an average dip of 77°; *— but those near Ontonagon „ „ 55° f only. Of 53 lodes in the Keweenaw district, 37 (0’7) have an easterly, ,, ,, and 16 (0*3) a westerly dip, whilst 65 ,, at Ontonagon.(1*0) all dip towards the north. Other obvious influences scarcely need recapitulation. The following columns set forth the extreme and average widths of lodes having different directions and dips. Directions « ( 'i N. to N.E.— N.E . to E.— E. to S.E.— S.E. to S.— Dips. S. to S.W. S.W. to W. W. to N.W. N.W. to N. Widths. Widths. Widths. Widths. Widths. feet feet feet feet feet feet feet feet feet feet feet feet feet feet feet G.X s-t M.J G. s. M. G. S. M. G. S. M. G. S. M. N— ( N.E. i I iEWE ENAY T. • • • • • • • • • • • ♦ 7*0 1*0 3-0|| • • • • • • 70 1-0 3-0|| N.E.— } E. 5 7*0 0-6 2-2*11 7*0 0-6 2-2U E-- | S.E. 5 9*7 0-5 2-3 97 0-5 2-3 S.E.— } s. i • • s - ] s.w. ] 3-0 1-0 2*511 3-0 1-0 2-0%l| S.W.— ) w. ] w.— \ N.W. S N.W. ) 0*6} 6-5 0-3 2-211 6-5 0-3 2-211 -N. 1 0-6§ Extremes. . 9-7 0*5 7*0 1*0 • • 7-0 0-3 • • 97 0-3 • • Means .. 2-3 • * • • 0-6^ • • • • 3-0 • • • • 2-2 — • • 2-4 “ * The dip of most of the veins in this district is nearly perpendicular, and generally pretty regular, the underlay, or deviation from a vertical line, being rarely more than 8 or 10 degrees.” Whitney, Metallic Wealth of the United States, p. 260. f At Ontonagon “ true veins coincide in direction with the beds of rocks, but dip at a different, and usually a greater angle, in the same direction with the formation.”— Ibid, p. 287. x G., s., m. Greatest,— smallest,—mean. § Single observations. II Lodes having similar directions, but opposite dips. ^ >> j >> • 410 W. J. Henwood, on the Direetions. r i N. to N.E. — N.E . to E.— - E. to S.E. — S.E. to S. — Dips. S. to S.W. S.W. to W. W. to N.W. N.W to N. Widths. Widths. Widths. Widths Widths. feet feet feet feet feet feet feet feet feet feet feet et feet feet feet G. S. M. G. S. M. G. S, G. G. a. M. G. S. M. N.— N.E. 0 NTON AGON • } } 2 -5 0-2 2-2 9- 0 • • • • 2*5 0-2 2-2 N.E. — E. E.— S.E. S.E. — 5 } * • • S. S— S.W. S.W.— 5 w. l • • w.— N.W. } 16- 0*3 4-5 16-0 0*3 4-5 N.W. -N. I 12* 0-2 3*1 12-0 0*2 3*1 Extremes.. 16- 0*3 — 12- 0-2 • • 2-5 0*2 • • • • • • • • te r c 0’2 • 0 Means 4-5 » • • • 3*1 m- 0 •• • 2*2 • • 3*2 The lodes in Keweenaw Point, therefore, average 2*4 feet in width ; those near Ontonagon „ „ 3*2 „ „ The following columns afford a comparison of the mean directions, dips, and widths, of the lodes in different districts.* Directions. Dips. Widths. feet. Keweenaw . 29° S. of E. & N. of W.f ... 77° J ... 2*4 § Ontonagon. 37° N. of E. & S. of W.f ... 56° f ... 3*2 § * The average direetions, dips, and widths of lodes , and cross-veins in Cornwall and Devon are— Directions, Dips. Breadths. feet. Lodes . 4° N. of E. & S. of W. about 70°. 3-61 Cross-veins .... 38° S. of E. & N, of W. ,, 80° ...... 4*03 Henwood, Cornwall Geol. Trans., v. pp. 247, 250, 277,279, Tables Cl., CIII., CIV., CVI.; Ante, p. 309. t Ante, p. 405, $ Ibid , p. 407. § Ibid, p. 409— Supra. Native Copper of Lake Superior. 411 The ingredients of the lodes , and their relations to those of the adjoining rocks, may be conveniently described together. Keweenaw Point. (a.) Immediately north of the crystalline green¬ stone,* some two miles and a half south-east of Eagle river, the Meadow mine has been opened in a coarse, granular trap-rock, composed chiefly of labradorite and hornblende, but containing also much chlorite.f Small, isolated, masses of quartz occur at intervals; and short, thin, lines of calcareous-spar,—mixed some¬ times with epidote—here and there traverse the other constituents. A few of the beds—which are seldom well defined—show traces of amygdaloidal structure. Within a width of forty fathoms three lodes were (in 1852) wrought J to a depth of about thirty feet; viz.— North , or North-east, Middle vein. South, or Sozith- vein. west. Directions. .. 25°—45° W. of N.—E. of S. 25° W. of N.— 25° W. of N.— E. of S. E. of S. Dtps • • • • _S.—S.W 68°—70°. N.—N.E. 65°— S.—S.W. 66°— • O o 75°. Widths .. S one vein ., 1*0 — 1*5 foot. ) \ two veins.. 0*6 & 0*8 „ ) .... 2*5 feet .... $ 0*6—0*8 foot. \ A line. In all these the most abundant ingredient is trap; which sometimes encloses, but is frequently enclosed * Whitney, Metallic Wealth of the United States, p. 255. Ante, p. 328. f Ante, pp. 399, 401. Jin 1853 four veins were wrought.— Whitney, Metallic Wealth of the United States, p. 266. 412 W. J. Henwood, on the in, quartz or calcareous-spar. These now and then occur separately; but more commonly they are mingled, ties of chlorite are scattered amongst the other minerals; epidote appears from time to time; and in narrow parts of the lodes Laumonite prevails. Mammillary con¬ cretions of prehnite often incrust the granules, threads, plates, and masses of native copper; which are numer¬ ous in the calcareo-siliceous portions; especially where the neighbouring (Country) rock is of amygdaloidal character. The directions of these, as well as of many other lodes , both in Keweenaw Point* and at Ontonagon,* may be traced by ranges of cuttings f and heaps of * “ Upon Keweenaw Point ancient pits have been found extending from Eagle- river eastward, a distance of twelve miles, along the base of the trap range. “ For a distance of nearly thirty miles [in the Ontonagon district] there is almost a continuous line of [similar works] along the middle range of trap, though they are not exclusively confined to it.” Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 161. “ Throughout the whole extent of the copper region, from the extremity of Keweenaw Point to a considerable distance beyond the Ontonagon, % % numerous excavations made for the purpose of procuring copper have been found.”— Whitney, Metallic Wealth of the United States, p. 250. “ Les vieux travaux sont nombreux au nord et au sud du greenstone, dans le district de la pointe de Keweenaw; ils sont plus nombreux et plus importants dans la contree d’Ontonagon, a Test et al’ouest de la riviere.” PtivoT, Annales des Mines, 5me Serie, vii, p. 280. t The Cliff vein “has been traced to the Lake, and found marked by ancient excavators.”— Whitney, Metallic Wealth of the United States, p. 265. “ During the winter of 1847—8 it was discovered that [at the location since occupied by the Minnesota Company] mining operations had been carried on many hundred years previously. * % % A series of open cuts had been made along the brow of the hill, % % * from which had been taken large quantities of rock, and probably of copper.” The line “ of ancient excavations w r as quite perceptible, even under a covering of three feet of snow; ” * % % notwith- Native Copper of Lake Superior. 413 rubbish,* * the works of an earlier race of miners. A few of these ancient openings exceed twenty feet in depth,f but many are less than ten ; J traces of copper are visible in most of them, but the largest masses have generally been found in the deepest pits.§ Exhausted standing, “they were, in great measure, filled with an accumulated mass of clay, sand, and mouldering vegetable matter.” Jackson, Report on the Geological and Mineralogical Survey of Lands in Michigan , hi, p. 745. Wiiitney, Metallic Wealth of the United States , p. 293. “ Near the Copper Falls Mine there are extensive ancient workings on a metalliferous belt; which is of a brownish color, quite soft, and everywhere filled with copper.”— Whitney, Metallic Wealth of the United States, p. 265. “ At the Forest Mines very extensive excavations had been made by the ancient miners, and quite large masses of copper were found near the surface in cleaning out the old workings, of which there are four parallel rows along the bluff.” Ibid, p. 297. Squier & Davis, Smithsonian Contributions to Knowledge, i. pp. 279—81. Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 159. Henwood, Reports of the Royal Institution of Cornwall , xxxv. (1853) p. 22. Rivot, Annales des Mines , 5me Serie, vn. pp. 278—82, * “ The rubbish taken from the mine is piled up in mounds, which can readily be distinguished from the former contour of the ground.” Foster & Whitney, Report on the Geology of the Lake Superior Land District , p. 159. f At the Minnesota mine “ one of the ancient excavations was found to be 26 feet deep on the vein,” and at the National Mine “ a shaft had been sunk in former times, to a depth of about 50 feet, on the lode.” Whitney Metallic Wealth of the United States , pp. 293, 297. X “Les vieux travaux sont arretes a une faible profondeur, de 3 a 12 metres, suivant la configuration des terrains, et n’ont pas £te pouss^s plus bas a cause des eaux.”— Rivot, Annales des Mines, 5me Serie, vn. p. 280. ^ When the earlier works at Minnesota were reopened “ to a depth of 18 feet, a mass of native copper ten feet long, three feet wide, nearly two feet thick, and weighing over six tons, was met with. It had been raised about five feet from its native bed by the ancient miners, secured there on oaken props, and abandoned apparently on account of the difficulty of raising it to the surface. Every pro¬ jecting point which was accessible had been taken off, so that the exposed surface was smooth. Below this the vein was subsequently found filled with a sheet of 414 W. J. Henwood, on the works are often filled with broken vein-stone.* * Egg-shaped and reniform masses of greenstone, porphyry, and quartzose-sandstone, in all which deep grooves have been cut—probably for the reception of withes or thongs, to secure, or to serve as, hilts,—lie scattered, either singly or in groups, amongst the rubbish,f—as well in the underground works as at the surface—of every mine in both districts. They copper five feet thick, and of undetermined extent vertically and longitudinally.” Jackson, Report on the Geological , and Mmeralogical Survey of Lands in Michigan, in. p. 745. Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 159. Whitney, Metallic Wealth of the United States, p. 293. “ On cleaning out an ancient shaft which had been sunk to the depth of about 50 feet at the National Mine, the remains of stidls or timbers forming a scaffold¬ ing, and a nearly continuous sheet of copper, were found.” Whitney, Metallic Wealth of the United States, p. 297. “ At the Central Mine, not far from Eagle Harbor, a mass of copper was found in one of the old pits that weighed forty-six tons.” Atlantic Monthly Magazine, xv. (March, 1865) p. 310. * “ These primitive workmen seem not to have lifted their rubbish to the surface, but to have thrown it behind them; thus filling their abandoned works as they proceeded.”— Henwood, Reports of the Royal Institution of Cornwall, xxxv. (1853), p, 22. “ At the Minnesota Mine an ancient opening was found to have been filled with rubbish as the miners advanced.” Whittlesey (Lecture at Montreal), Lake Superior Miner, hi. (12th September, 1857) p. 2. f “ Large quantities of stone hammers, or boulders of an ovoidal shape, with a groove cut around them near the middle, probably for the purpose of attaching a handle with a withe, were found buried in the rubbish which filled many ancient works at the Minnesota Mine. % % % Furthermore we found half-finished scalp¬ ing-knives and spear-heads in the soil near the Eagle river copper mine; and those instruments bear ample evidence of their Indian origin.”— Jackson, Report on ■the Geological and Mmeralogical Survey of Lands in Michigan, hi. pp. 374, 745. “ The amount of ancient hammers found in the vicinity of the Minnesota Mine exceeded ten cart-loads. # * * They are made of greenstone or por¬ phyry pebbles, with a groove, single or double, cut around, by which a withe was attached. One of the larger class weighed 39| lbs.; smaller specimens were of -5 or 6 lbs. each. “ In addition to these relics a copper gad, with the head much battered, and Native Copper of Lake Superior. 415 weigh mostly from six to eight pounds each, but some are much heavier. Notwithstanding they are the hardest pebbles amongst the drift , in the beds of rivers, and on the lake-shores, many of them appear chipped by use. Knives, spear-heads, a gad (wedge), and a chisel of hammered copper; beside a broken bowl and some shovels of wood; have been discovered, from % time to time, in and near the mines. From the presence of wood-ashes in the works, it has been inferred that fire was occasionally used* * to soften the rock. a copper chisel, with a socket for the reception of a handle, were brought to light. % * * “ In cleaning out one of the pits at the Forest mine at a depth of ten feet the workmen came across a fragment of a wooden bowl # * * .” Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 160—1. Squier & Davis, Smithsonian Contributions to Knowledge, i. p. 280. Henwood, Reports of the Royal Institution of Cornwall, xxxv. (1853) p. 23, Fig. 1, 2. Whitney, Metallic Wealth of the United States , p. 250. Rivot, Annales des Mines, 5 me Serie, vii. p. 279. Lapham, Smithsonian Contributions to Knowledgey vn. pp. 74—7. Whittlesey, Lake Superior Miner, hi. (12th September, 1857) p. 2. Atlantic Monthly Magazine , xv. (March, 1865) pp. 308—10. * “ Remnants of charcoal were found, at numerous places, lying on the sur¬ face of the rock.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 161. (t Fragments of charcoal have been often noticed, indicating that the method pursued was similar to that still employed in some of the European mines, in the use of fire to attack the rock.” Whitney, Metallic Wealth of the United States, p. 250. “ The mode of mining pursued by the aborigines was to build fires to soften the rock, and then break out the metal by means of stone hammers.” Whittlesey (Lecture at Montreal), Lake Superior Miner , hi. (12th September, 1857), p. 2. Squier & Davis, Smithsonian Contributions to Knowledge, i. p. 280. Rivot, Annales des Mines , 5me Serie, vir, p. 280. Atlantic Monthly Magazine , xv. (March, 1865) p. 311. Ante, pp. 51—2. L L L 416 W. J. Henwood, on the Pines two or three feet in diameter were still growing on ancient heaps of rubbish, at the Meadow mine in 1852; and yet older and larger trees, covered the earlier works of other mines.* From the extent of the earlier works,! and from the numbers of rude, yet serviceable, tools still remaining,! it may be inferred that a large population was once engaged in searching for copper;—the depths of nu¬ merous pits § show that—in them at least—-operations were long continued ;—and that many were abandoned several centuries ago is shown by the ages of the trees || * “ At the Vulcan mine extensive open cuts, made by the ancient miners, have been filled nearly to a level by the accumulation of soil, and we find trees of the largest growth standing in the depressions; and also find that trees of a very large size have grown up and died, and decayed many years since: in the same places there are now standing others of over three hundred years* growth.” Squier & Davis, Smithsonian Contributions to Knowledge , i, p. 280. “Upon an [artificial] mound of earth we saw a pine stump, broken fifteen feet from the ground, ten feet in circumference, which must have grown, flourished, and died since the earth in which it had taken root was thrown out. Mr. Knapp [of the Minnesota mine] counted three hundred and nine-five annular rings on a hemlock, growing under similar circumstances, which he felled near one of his shafts. Thus it would appear that these exploitations were made before Columbus started on his voyage of discovery.” Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 160. “ There is plenty of evidence that the timber of full size, now flourishing in the old excavations, is of the second growth at least since the mines were deserted. Hs % # It must not be forgotten, however, that the same species of tree does not immediately succeed, but those of other kinds take its place.” Whittlesey (Lecture at Montreal) Lake Superior Miner, in. (12th September, 1857) p. 2. (Abridged.) Jackson, Report on the Geological and Mineralogical Survey of Lands in Michigan, hi. p. 745. Henwood, Reports of the Royal Institution of Cornwall, xxxv. [1853) p. 22. Whitney, Metallic Wealth of the United States t p. 250. Hivot, Annales des Mines, 5me Serie, vn. p. 279. Lubbock, Pre-Historic Times, p. 202. Atlantic Monthly Magazine, xv. (March, 1865) p, 311. t Ante, p. 412. $ Ibid, p. 414. $ Ibid, p. 413. || Supra. Native Copper of Lake Superior. 417 found rooted in the broken vein-stone and other rubbish with which they were mostly filled; * ** but whether all were wrought at the same time,f or by the same people,J is unknown. Notwithstanding the extent and richness of the ancient mines,§ the tools and weapons of copper, yet discovered in and near them, have 4>een very few; || • Ante, p. 414. f “ Dans toute la contree dans laquelle les explorations recentes ont signal^ le cuivre natif, on a constatd l’existence d’anciens travaux d’exploitation: * * * en d’autres points les excavations paraissent bien plus modernes, et abandon6es tout recemment.” Rivot, Annates des Mines , 5me Serie, vn. p. 279. ** From the amount of work accomplished by the ancient miners, and their want of facilities, their operations must have extended through a period of five hundred years. From the fact that no remains of houses in that severe climate are found, no roads or other improvement made by permanent inhabitants, the conclusion seems inevitable that the mines were wrought only in summer, and that by some people who came hither for the purpose, and departed with the approach of winter.”— Whittlesey (Lecture at Montreal), Lake Superior Miner , in. (12th September, 1857) p. 2. Atlantic Monthly Magazine , xv, (March, 1865) p. 312, $ “ All will assign to these excavations a high antiquity; but whether they were made by a race distinct from the Indian now inhabiting the region, is a matter of extreme doubt.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 162. “ No remains of habitations or burial-places, which might furnish a clue to the race by which this work was done, have yet been found,” Whitney, Metallic Wealth of the United States, p. 250. “ En rapprochant ces faits des renseignements rapportes par les missionnaires jesuites et les plus anciens voyageurs, on peut conclure que les mines de cuivre natif ont 6te de tout temps exploitees par les Indiens peaux rouges, residant, en faisant seulement des excursions dans la contree.” Rivot, Annalcs des Mines , 5me Serie, vn. p. 280. “ Upon a general consideration of the earth-works in Wisconsin, we are led to the inference that the men who built them, and those who first opened the Lake Superior copper mines, were one and the same people ; and that they were none other than the ancestors of the present race of Indians.” Lapham, Smithsonian Contributions to Knowledge, vii. p. 26. Atlantic Monthly Magazine, xv. (March, 1865) p. 312. § Ante, p. 413. (| Ibid, p, 415. 418 W. J. Henwood, on the but from aboriginal earthworks in Wisconsin,* * * § Ohio,t and Canada J also, axes,§ chisels,|| borers,tubes ,** * * * knives/ff, spear-heads,arrow-heads,§§ bracelets,|||| gorgets, 1 buttons,*** * * §§§ and beads Iff are, from time, obtained. The metal, generally, is remarkable for its purity; but now and then granules of native silver are embedded in the copper,§§§—a mode of association peculiar to this region. * Lapham, Smithsonian Contributions to Knowledge, vn. pp. 1-92. Whittlesey (Lecture at Montreal), Lake Superior Miner . ill, (12th September, 1857) p. 2. Atlantic Monthly Magazine , xv. (March, 1865) p. 312. t Squier & Davis, Smithsonian Contributions to Knowledge, i. pp. 1—306. Whittlesey, Lake Superior Miner, in. p. 2. Atlantic Monthly Magazine, xv. p. 312. $ Squier & Davis, Smithsonian Contributions to Knowledge, i. p. 201. § Ibid , i. p. 197, Fig. 81, 82. || Lapham, Ibid, vir. p. 88, Fig . 60. U Squier & Davis, Ibid, i. p. 200, Fig. 85. ** Ibid, i. p. 207, Fig. 93. tt Ibid, i. pp. 201—2, Fig. 87—3. tt Ibid, pp. 201—2, Fig. 86—1, 2 ; 87—1,2. Lapham, Ibid, vii. p. 77, Fig. 3, 4. 1111 Squier & Davis, Ibid, i. p. 204, Fig. 88. Ibid, i. pp. 205—6, Fig. 89, 90. *** Ibid, i. p. 207, Fig. 94. tft Ibid, I. p. 207, Fig. 96. +++ “ The axes were found, upon analysis, to be pure copper, —unalloyed, to any perceptible extent, by other metals.”— Ibid, i. p. 202. “ A slice of copper from the great mass at the Copper Falls mine, was found on analysis to be pure copper. # % % A strip from one of the largest masses at the bottom of the Cliff mine was dissolved in pure nitric acid, and left # # # but a minute portion of silex. * % % “ A piece sawn out of a large crystal from the Cliff mine when dissolved in pure nitric acid and distilled in water left scarcely 0’00107 its weight of silex.” Jackson, Report on the Geological and Mineralogical Survey of Lands in Michigan, in. pp. 475—6. §§§ As the copper discovered in ancient mounds of earth “ is occasionally found combined with silver in the peculiar manner characterizing the native deposits Native Copper of Lake Superior . 419 All these tools, weapons, and ornaments, however, are of native copper; for—notwithstanding the earlier miners often applied fire to the rocks,* *—no trace of molten f metal has been found either in the earthen mounds or in the mines. (5.) The North American mine (Table XI,), about three miles and a half south-west of Eagle river, upon the shores of Lake Superior, we are led to conclude that it was principally, if not wholly, derived from that region.” Squier & Davis, Smithsonian Contributions to Knowledge , i. p. 279. “ In the copper tools found in Ohio, are seen spots of native silver ; a fact well known in relation to Lake copper.” Whittlesey, Lake Superior Miner , m. p. 2. “ In these copper relics, blotches and grains of native silver are found.” Atlantic Monthly Magazine, xv. p. 309. " The native silver is scattered through the metallic copper, of the Lake Superior region, in such a manner that each metal remains entirely free from alloy with the other, although the junction of the two at their edges is a per¬ fect one.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 178. “ In the Lake Superior veins native silver occurs intimately united with copper, being, as it were, soldered to it, or forming blotches and specks within it, but the two metals are never found alloyed together.” W hitney, Metallic Wealth of the United States , p. 278. Rivot, Annales des Mines , 5me Serie, vn. p. 314. * Ante, p. 415. f “ Considerable quantities of wrought, and some small fragments of un¬ wrought native copper, have been extracted from the mounds. * * # The metal appears, in all cases, to have been worked in a cold state.” Squier & Davis, Smithsonian Contributions to Knowledge , i. p. 279. “ There is no evidence that the race by whom the tumuli were built possessed sufficient know-ledge of the metallurgic art to reduce and purify the ores of copper.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, i, p. 158. “The Ohio people of the Mound Epoch did not possess the art of smelting copper.”— Whittlesey, Lake Superior Miner, hi. p. 2. Lubbock, Pre-IIistoric Times, p. 418. “ I have never seen a copper relic [from this region] that had the appearance of having been melted. They invariably appear to have been cut and hammered into shape from masses of native copper.” Atlantic Monthly Magazine, xv. p. 309. 420 W. J. Henwood, on the has been wrought in the granular and amygdaloidal trap immediately south-east of the greenstone, to a depth of nearly seventy fathoms, on a lode which bears 38°— 45 ° S. of E.—N. of W,—dips 60°—85° N.E.,— and varies, from less than an inch to about six feet, in width.* * * § On the north-east, however, two nearly parallel, though subordinate (branches), veins unite with it at different levels : f but neither of them has been traced through the greenstone.^ Their more abundant ingredients are calcareous- spar, quartz, and prehnite; but Laumonite, chlorite, epidote, hornblende, and disintegrated felspar (? labra- dorite),—though generally present §—occur in smaller quantities. Most of them are more or less mixed; but—here and there—one or other is separately aggre¬ gated. Sometimes, also, blocks of trap are imbedded in and transfused with the other components of the vein-stone. A cellular structure—oblique to both the * Jackson, Foster, & Hill, Report on the Geological and Mineralogical Survey of Lands in Michigan , in. pp. 458, 760. Foster & Whitney, Report on the Geology of the Lake Superior Land District, I pp. 132, 140. Whitney, Metallic Wealth of the United States, p. 279. Hivot, Annates des Mines , 5me Serie, vn. p, 315. f “ Near the 155 foot level a small vein or feeder unites with the lode, [which immediately] below increases in width, and becomes highly metalliferous. At a depth of 275 feet another feeder comes in, and, like the former—enriches and expands the lode still further.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 132; Whitney, Metallic Wealth of the United States, p. 277. X “The vein was not exposed in the face of the cliff.”— Jackson, Report on the Geological and Mineralogical Survey of Lands in Michigan, hi. p. 458. § “ The vein-stone consists of calc-spar, laumonite, prehnite, chlorite, apophyl- lite, and drusy quartz.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p, 146. Native Copper of Lake Superior. 421 dip and direction of the lode —is assumed, at intervals, by portions in which every cavity is encrusted with minute crystals of quartz. Fig , 26. THE NORTH AMERICAN MINE. Massive and cellular quartz sprinkled with native copper. Natural size. Longitudinal joints frequently divide the lode into # parallel (combs) slices,* which are now *and then characterized by either the proportions or the disposition of their constituents. Wherever the adjoining (Country) rock is of amyg- daloidal structure, the lode contains native-copper; usually in grains and small lumps,')' but occasionally * Boase, Primary Geology , p. 179. Burr, Mining Review , in. (1836) p. 237. Fox, Report of the Royal Polytechnic Society of Cornwall , iv. (1836) p, 89. De la Beche, Report on the Geology of Comwall i Devon , and West Somerset , p. 339. Hen wood, Cornwall Geol. Trans , v. p. 179. t “ Through the entire length of the lower level [180 feet from the surface] the lode has been found good, containing in some places mass copper. From an examination at the depth of 95 feet, it is inferred that the veinstone is 3 or 3^ per cent, richer than that taken from the second level [60 feet deep]. The stamp- work, at present yields about 7 per cent. % * * From every bunch of ore containing 30 tons there are taken 4 tons of what is called barrel-work, yielding 40 per cent of copper, and the addition of the masses at 60 per cent, will make the average yield of the contents entire not far from 9| per cent.” Foster & Whitney, Report on the Geology of the Lake Superior Land District , i, p. 132. 4*22 W. J. Henwood, on the in masses of many hundred-weight, and at times : — though less frequently,—of several tons, each. The largest bodies of metal,—which are most numerous in the south-western (lower) part of the lode* ** —enclose, however, considerable quantities of vein-stone. (c.) The Cliff mine ( Table XII .)—immediately north-east of the North American “ location,”—was, in 1845, opened beneath the precipice f of crystalline (greenstone), hornblende labradorite, and chlorite ; ^ and—having been continuously worked ever since—is now (1865) one hundred and thirty fathoms deep.§ The crystalline mass is conformably underlaid by trap- rocks ; of, perhaps, much the same composition,|| but generally of granular, and frequently also of amyg- daloidal, structure. The varieties alternate in somewhaf ill-defined layers of unequal thickness; all, * “ At 180 feet below the surface, a sheet of native copper, one foot in diameter, was seen to occupy the foot wall, and to extend from the bottom to the top of the gallery. The other portion of the vein, one foot in thickness, was composed of calc-spar, quartz, chlorite, and epidote, filled with small spangles of copper.” Foster & Whitney, Report on the Geology of the Lake Superior Land District , I. p. 132, PI. IX. f Ibid, i. PI. VIII.; ii. pp. 87—8. $ Ante , pp. 398—9. $ Mining Journal (2nd September, 1865), xxxv. p. 567. || Whitney, Metallic Wealth of the United States, p. 253. Rivot, Annales des Mines, 5me Serie, vn. p. 225. Ante, pp. 398—402, 11“ The zoolitic minerals, so common in the veins, and often filling the amyg- daloidal cavities of the trap, do not appear to form an essential ingredient of the compact trappean rocks.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , n. p. 90. ** “ At the foot of the bluff * * * lies a fine-grained trap-rock, through which run numerous and parallel belts of amygdaloid, varying in thickness from 3 to 12 feet.”— Mining Journal (2nd Sept., 1865), xxxv. p. 567. Native Copper of Lake Superior. 423 however, dipping 25°—30° * * * § N.— N.W. The im¬ bedded minerals are, generally, either calcareous-spar, chlorite, felspar-clay, hornblendic matter, or prehnite; but neither Laumonite, zeolite, nor native copper is uncommon, f The only lode yet discovered bears about 21° W. of N.—E. of S., dips 70°—85° E.,—and—varying from an inch to five feet,—averages from fifteen to eighteen inches, in width The principal earthy ingredients § are quartz, cal- * Whitney, Metallic Wealth of the United States , p. 277. Rivot, Annales des Mines, 5me Serie, vii. p. 312. Mining Journal, xxxv, p. 567. Table XII. column 6. f Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 138. Rivot, Annales des Mines, 5me Serie, vn. p. 227. Ante, pp. 402-3. $ “ The lode bears north 27° east (sic); underlie 10° to the east, average width 18 ins.”— Jackson, Foster, & Hill, Report on the Geological and Mineralogical Survey of Lands in Michigan, in. p. 760. “ The lode,—hardly more than an inch or two wide at the surface—is about 15 inches wide on the average ; bearing north 27° west, with an underlie of 10° to the east.— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 146. “ The vein is remarkably regular in its course, which is about north 27° west, and its underlay is about 10° to the east. In the lower levels its dip is more varying, Some parts of it expand to three or four feet in width, other portions are pinched up to a few inches, but its average width is probably from 15 to 18 inches.”— Whitney, Metallic Wealth of the United States , p. 277. “ Le seul filon de Cliff-Mine * * % est dirige N. 27° O. & # # II plonge vers Test sous un angle de 7 5° h 85°; sa puissance est tres-variable; elle atteint 2 metres et meme 3 metres aux renflements et a la reunion des veines, et descend parfois a 0m 25.”— Rivot, Annales des Mines, 5me Serie, vn. p, 311. “ The vein varies in size from 1 to 5 feet, bears a little west of north, and underlies a little east.”— Mining Journal, xxxv. p. 567. § “ The veinstone is composed of several gangues; drusy quartz, calc spar, chlorite, and prehnite predominate.”— Jackson, Foster, & Hill, Report on the Geological and Mineralogical Survey of Lands in Michigan , m. p. 761. “ Near the surface the gangue was mostly prehnite, * * * Furtl^pr down the veinstone consisted of a series of reticulations of laumonite; [and at still M M M 424 W. J. Henwood, on the careous spar, chlorite, and prehnite; but Laumonite, zeolite, and felspar-clay are less plentiful; and epidote exists in yet smaller proportion. All these often occur intimately mixed; but sometimes particular minerals are associated with certain others only; and less fre¬ quently one or another is segregated * * from the rest. Of the quartz, when thus separate, considerable portions are, at the same time, of both cellular and crystalline structure, j* Masses of trap—simply granular in some, but amygdaloidal in other, places, yet always resem¬ bling the neigbouring (Country) rock—are frequently enveloped in the veinstone. Some of these (Horses) are of such dimensions that they rather split the lode into branches , J than form integrant parts of it; others, however, are so small, that they are thoroughly greater depths of] drusy quartz, calc-spar, laumonite, prehnite, and chlorite.” Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. pp. 128, 146. The veinstone is principally quartz, calc, spar, and the zeolitic minerals, and is characterized by an abundance of finely-crystallized minerals, of which drusy quartz is the most common; it is associated with apophyllite, prehnite, and calc- spar, in various crystalline forms.” Whitney, Metallic Wealth of the United States, p. 277. “ La gangue est composee de quartz, chlorite, calcaire et de matiere rouge, presentant toutes les variates de disposition. * * * Les veinules de laumonite et d’6pidote sont assez frequentes, et les geodes, qui se trouvent assez souvent dans les parties puissantes du filon, sont remplies par l’argile et tapissees de tr6s-beaux cristaux de quartz, d’analcime, de baryte sulfat^e, de prehnite et raeme de cuivre natif.”— Rivot, Annales des Mines,5me Serie, vn. p. 311. * Sedgwick, Proceedings of the Geological Society, i. p. 283. f Ante, p. 420. X Boase, Primary Geology, p. 179. Burr, Mining Review, hi. (1836) p. 227. Henwood, Edinburgh New Phil. Journal , xxii. pp. 156, 165; Cornwall Geol. Trans., v. pp. 210—12. Fox, Report of the Royal Cornwall Polytechnic Society, iv. (1836) pp, 99, 124. Ante , pp. 20, 23, 181, 191,-3,-4, 251-9, 312,-17,-28, 381. Native Copper of Lake Superior . 425 penetrated and pervaded * * * § by its calcareo-siliceous constituents. The adjoining amygdaloid, on the con¬ trary, includes nodules of many different vein-stones. Longitudinal joints occasionally divide the lode into (Combs) slices; j' each of which—from some pecu¬ liarity in the nature, proportion, or disposition of its ingredients—possesses, commonly, a character of its own. Every part of the lode yet seen has contained native copper mostly in (Stamp-work §) particles and * Fox, Report of the Royal Cornwall Polytechnic Society , iv. p. 99. Henwood, Cornwall Geol. Trans-, v. pp. 211—12; Ante, pp. 194, 250, 312, 381. + “In the Cliff vein, there are two combs.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 172. X “ The copper occurs here, as in some other mines of this region, in masses of great size, from a few hundred pounds up to nearly one hundred tons, and the vein is not only rich in these, but also furnishes a large quantity of stamp- work, containing an unusually high percentage of copper.” Whitney, Metallic Wealth of the United States , p. 278. § “ Stamp-work —which forms a large part of every vein—is prepared [for the stamping-mill ] by being calcined and broken into small fragments. The roasting is effected in the open air. The rock is arranged in alternate layers with billets of wood, and then fired, and allowed to smoulder for forty-eight hours. Care has to be taken to distribute the heat as uniformly as possible, and not to allow any part of the copper to become fused and oxidized, as a loss would thus ensue.” Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 183. Whitney, Metallic Wealth of the United States , p. 261. Jackson, Report on the Geological and Mineralogical Survey of Lands in Michigan , iii. p. 468. “ La gangue contient une forte proportion de cuivre en petits grains, et rend jusq’ a 5 p. 100 de metal a la preparation mechanique.” Rivot, Annales des Mines , 5me Serie, vn. p. 311. Whitney, Metope Wealth of the United States, p. 278. “ As the country becomes settled, and the price of labor falls, and greater method is introduced into the works, a rock containing a smaller percentage of copper may be profitably worked.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 183. “ Throughout this district the stamp-head is always shod, so that instead of using the heads until they are worn light enough to be of little service, as soon 426 W. J. Henwood, on the •4 grains, but frequently also in (Barrel-work # ) lumps as the shoe is worn the head is taken out, and the old shoe is replaced by a new one, the whole occupying but a few minutes. The stamps are stopped twice a day to clean out the copper that accumulates under the heads. The holes in the grates are not less than ~ inch in diameter. * * # The quantity [of vein-stone] stamped monthly is about 1500 tons ^ # % and the weight of copper extracted from it is about 30 tons, [2 per cent.] # % # The cost of crushing and treat¬ ment is only 115 cents (four shillings and nine pence half-penny) per ton of [stone] dirt.”— Mining Journal , xxxv. p. 567. At the Northwest mine, during the second quarter of 1853, 1295*52 (Avoir.) tons of Stamp-work afforded 17*72 tons (0'0136 its weight) of copper; or 30*65 lbs. per ton of vein-stone. “ After the mine had been laid open [by shafts, levels , and winzes ] the cost, of extracting the Stamp-work , and of all the operations necessary for preparing the copper for the market was ” s. d. Extracting (ttopbyj the » 2 ,j ollars . (8 4 Stg.) 4? ton of stone. Raising to the surface... Roasting (fuel, carriage and labour) . Stamping, dressing , and repairs of machinery.. Petherick (Whitney’s), Metallic Wealth of the United States, p. 271. At the Copper Falls mine two stamp-heads which weighed 2200 lbs. each, were lifted two feet, and made some seventy blows per minute, crushed in 246'9 days (1859—60) 16575 (Avoir.) tons of vein-stone; a rate which—varying from 27*01 to 36 20—averaged 33*57 tons (75188 lbs.) per head in twenty-four hours. The quantity of copper extracted was 17*98 tons (0*00108 its weight); or 24*3 lbs. per ton of vein-stone. 26 cents . .(1 1 ‘ ) f> • • 41*5 „ ..(1 CO ) »> • • 1 ,, 74*5 „ ..(7 ) M 4 dollars 42 cents.(18 5 „ ) 99 During the same period s. d. The exploratory works (shafts, ( ( cost on an ) levels, winzes. &c.). $ ( average., j 44 cents (1 lostg.) ( (JP* ton of ( stone. Extracting (sloping) the vein-stone „ 97*5 „ 4 Of . >> Raising to the surface ........ „ 11 „ o 5± It Preparation for, & conveyance ) to, the stamps . $ ” 80*5 „ 3 H tt Stamping, dressing, and repairs \ of machinery.$ ” 98 „ 4 1 t> Carriage to the wharf, shipping- ) charges, &c.. $ ” 7*5 „ 0 3f »? Agencies, & incidental expenses. „ 25*5 „ 1 0| a 3 dollars 64 cents (15 2) tt William Pethericik, Esq., Superintendent of the Mines, MSS. * u The pieces which are raised to 30 per cent, of metal by beating off the rock 427 Native Copper of Lake Superior. of several pounds, and at times in (Masses* ) bodies are packed in barrels, and called Barrel-work .”— Jackson, Report on the Geological and Mineralogical Survey of Lands in Michigan, in. p. 4GS. “ Barrel-work is the name given to the smaller masses of copper, which are too large to go under the stamps , and too small to be shipped separately. It includes masses of copper in bunches and string-like forms, which are firmly bound together with a greater or less amount of the veinstone, and weighing from a few pounds up to several hundred. These smaller masses are dressed by the hammer, to free them as much as possible from the adhering rock, and bar¬ relled up in stout casks which hold from five to eight hundred pounds of metal and rock. * % The barrel-work at the Cliff mine is estimated at 50 per cent, of pure copper.— Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 182. Whitney, Metallic Wealth of the United States , p. 261. Iiivot, Annales des Mines , 5me Serie, vn. p. 288. * “ When a large sheet of copper occurs in the vein, the rock is removed from one side of it, and it is thrown down by means of a sancl-blast.u Masses have been detached from the vein which were estimated to weigh 60 or 70 tons, mostly of solid copper, in an irregular, flattened, tabular shape, now expanding to a width of from 2 to 3 feet, and then contracting to a few inches, but firmly united. Of course * * # it is important that as little of the process of subdivision as possible should be done underground, since the operation impedes the work of the mine and is less conveniently executed in a confined space % X * where the mass cannot be readily moved. # % % The process of dividing the masses, at present is as follows, and is the same whether above and below the surface. A groove is cut diagonally through the mass, at a convenient point, where the copper is very pure and the thickness comparatively small. To effect this, one person guides a chisel about three-quarters of an inch in width,* and another strikes it with a heavy sledge, % X % until at last a chip c of copper is taken out several inches in length, # # * If the copper be perfectly pure, the operation pro¬ ceeds rapidly; but when quartzose matter intervenes, the labor is more tedious. % # * When the masses have been brought to the surface, they are still further subdivided, if necessary, into pieces varying from one to two tons—such may be conveniently transported to the lake, whence they are shipped to market.” Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 182. “ L’abatage des grandes masses est assez complexe: on commence par le de- a “ A small drift is driven for a few fathoms behind the vein, and several—in some cases fifty— 25 lb. kegs of powder are put in, closely covered with fine dirt, and fired; this is termed Sand-blasting .”— Mining Journal, xxxv. p. 567. b “ The chisels are about £ of an inch in width.” Whitney, Metallic Wealth of the United States, p. 260. “ Les rainures ont 2 centimetres (0’78 inch) de large.” Rivot, Annales des Mines, 5me Serie, vn. p. 285. c “ Copper chips crumple to about two-thirds the [length of] the surface from which they are cut. At the Cliff mine a copper chip some thirty inches in length was cut from a mass which had been brought to the surface.”— Lah e Superior Miner, ii. (1st August, 1857) p. 2. 428 W. J. Henwood, on the of many tons each. Some of the largest consist, here and there, of parallel sheets; varying—from a fraction gager au toit et au mur, en ne laissant de ce c6t£ qu’un vide peu large du c6te du mur. Si les dimensions en hauteur ne sont pas trop grandes, on fait tomber la masse d’un seul morceau sur le niveau inf^rieur au moyen de barils de poudre places derri&re. Si au contraire la masse de cuivre s’^tend d’un niveau a l’autre, on la divise au ciseau en grands morceaux qu’on puisse detacher d’une piece, et en choisissant pour les lines de division les points les moins epais. On fait en- suite tomber a la poudre les morceaux coupes successivement, en commen>( £2: 18 :4 > “ Three men take ten hours to cut a groove nine inches long and nine inches deep with a three-quarter inch chisel.” Captain J, T. Brown, Manager of the Ontonagon Copper Mine, MSS. >> » >> »> Native Copper of Lake Superior. 429 of an inch to several inches—in thickness, and—from a few feet to many fathoms—in length and depth. In various parts of their range, however, the selfsame sheets ,—are separated by thin slices (Horses) of the different vein-stones,—touch, but slightly cohere,—and unite to form masses of considerable thickness. These are mostly of either fibrous or granular structure; * * It was ascertained by Dr. Jackson that the specific gravity of a chip , supposed to have been condensed in process of being cut, from one of the largest masses found at a depth of 40 fms. in the Cliff mine, was 8-8900 of a crystal from the Cliff mine . ,, 8 9300 of a slice from a large mass at the Copper Falls mine ., 8*9308 Mean.... 8-9169 Report on the Geological and Mineralogical Survey of Lands in Michigan , hi. pp. 474—6. (a.) Ordinary smelted copper, examined at different stages in the process of (poling) refining, varied in specific gravity from 8-2980 to 8 6540. Napier, London, Edinburgh, and Dublin Phil. Mag. 4th Series (1853), v. pp. 489—90. (a—1.) “ The specific gravity of electrotype copper, melted under charcoal and treated in various ways, is shown in the following table « Cast under ordinary circumstances, and therefore } e 0 . D tA - A Tesicular ...J " from 8 ' 5050 t0 8 53o ° „ in a mould containing charcoal enough to "% cover the surface and exclude all action of > .. ,, 8-9220 ,, 8-9520 the air.. .:. . 3 Poured through a current of coal-gas which en- > 0 . 0,1 on o.ocoo tered and filled a covered mould.• • • j * * ” ” Dick, London , Edinburgh , and Dublin Phil. Mag., 4th Series, (1856) xi. pp. 424—5. Percy, Metallurgy, 1 . p. 286. “ The difference occasioned by pouring the metal through an oxidizing me¬ dium like atmospheric air, or a reducing one like coal gas, was observed many times; and it was found easy % # * to cast from the same crucible one ingot of copper which should be porous and, immediately afterwards, another which should be perfectly free from porosity. # % % . “ Steam * * % exerts neither an oxidizing nor a reducing action.” Dick, London , Edinburgh, and Dublin Phil. Mag., 4th Series, xi. p. 423. Percy, Metallurgy, 1. pp. 267, 277. ( a —2.) Copper precipitated from a solution of the sulphate of copper (cement- copper) and melted under common salt, varied in a specific gravity from 8-8850 to 8*9070. Specimens subjected to the pressure of suitable appara¬ tus underwent the following changes;— 430 W. J. Henwood, on the but some of the largest and richest contain (vughs) Specific gravity before compression. 8-8910 8-8990 8-8850 8-9070 Pressure, lbs. CAvoir.) per square inch. 10013 *» 150-20 300-40 Specific gravity after compression. 8-9220 8-9190 8-9280 8-9310 Ratio. Uncompressed metal = 1* 1-003487 1-002247 1-Q04840 1-002695 Makchand & Scheerer—Percy, Metallurgy , i. pp. 284—5 (abridged). (5.) “The following are the appearances which copper in different stages of poling has under the microscope ;— 1st. Ready for poling. Red-brown colour, vitrified, sandy fracture. Sp. gr. 8-491. 2nd. Slightly poled. Colour redder than the last, sandy fracture, a less vitre¬ ous appearance. Sp. gr. 8-526 . 3rd. Colour lighter with more lustre, fracture hard, not sandy but vitreous. Sp. gr.‘8-481. 4th. Longer poled. Colour brighter, with more metallic lustre, less vitreous, and having minute cavities. Sp. gr. 8'397. 5th. Near to tough pitch. Colour still brighter, fracture full of minute cavities as if the metal had set whilst gas was escaping, slightly vitreous. Sp. gr. 8-582. 6th. Tough pitch. Colour very bright, lustre metallic, the cavities seemed collapsed, giving a fracture resembling a honey-comb, strongly compressed. Sp. gr. 8*654. 7th. A little overpoled. The collapsed cells extended ; some of the cavities oval, as if a gas had escaped. Sp. gr. 8-594. 8th. Further overpoled . Full of cavities, fracture crystalline and vitreous. Sp. gr. 8*518. 9th. Much overpoled . Very hard and vitreous, fracture like a crystalline net¬ work. Sp. gr. 8-298. “ These appearances seem to indicate the changes going on within the metal during poling , and the specific gravity of each corresponds with its appearance.” Napier, London , Edinburgh , and Dublin Phil. Mag., 4th Series, v. pp. 489—90 (abridged). “ When copper at tough pitch is cast into a narrow open ingot mould * * * and the ingot is broken in two cold, its fractured surface is even, close-grained, free from fibres or cavities, presenting, especially towards the centre, numerous shining grains of bright metallic lustre.”— Percy, Metallurgy , i. p. 266. “ When tough pitch copper is kept melted under charcoal during a sufficient time, and is then laded into a narrow open mould * * * it is more or less brittle, so that the ingot may be easily broken. Its fractured surface is more uneven than that of tough pitch copper, and it appears fibrous throughout.” Ibid , p. 268. “ Copper from different works may differ a little in the diameter of the cells, and consequently in the number contained, but the general range seems to be Native Copper of Lake Superior. 431 cavities, lined with crystalline facets, more frequently than with perfect crystals, of copper; encrusted, now and then, with quartz, calcareous-spar, and other earthy substances.* Such portions of the vein-stones as adjoin. from 500 to 1000 in the linear inch. * * * The partitions between the cells are so thin that there seem to be openings from each one to its surrounding cells ; so that—as in silver—there is an internal communication throughout the entire mass.”— -Vivian, Report of the British Association (1861), Part n. p. 35. ** When melted copper is oxidized by exposure to the air, % % % the oxide formed is dissolved in the metal.” Napier, London, Edinburgh , and Dublin Phil. Mag., 4th Series, v. p. 287. “ Copper in a state of fusion has the property of dissolving dioxide of copper to a considerable extent. When it contains this oxide to the maximum, it is technically called dry copper . % * % An ingot of copper in its driest state Ht * * contained from 9’34 to 10*21 per cent, of dioxide.” Percy, Metallurgy, i. pp. 264— 5. “ The highest amount of dioxide detected [in tough pitch copper] was 2*95 per cent.”— Ibid, p. 266. (5—1.) “ Electro-deposited copper shows, under the microscope, no trace of vesicular structure.”— James Napier, Esq., of Glasgow, MSS. “ The copper precipitated from mineral water, on scraps of wrought iron and shreds of tin-plate, near the mouth of the Gwennap Adit in Cornwall ( Corn. Geol. Trans, v. pp. 89*, 422—3), at the Parys and Mona mines in Anglesea (Annales des Mines, xiii. (1826) pp. 229—35), and at Cronebane, Ballygahan , Ballymurtagh, and Connorree in Wicklow (Records of the School of Mines , i. p. 378), as well as the native copper of this country, of South America, and of Cuba, is slightly mixed with particles of ruby-copper, and mostly crystalline; but of vesicular structure it shows no trace. “ The native copper of Lake Superior is sometimes thinly invested with ruby- copper, at the surface; but never at greater depths. The extremities of the larger masses are here and there crystalline; but their internal structure is always granular or fibrous.” William Vivian, Esq., Manager of the Parys Mine, MSS. The foregoing comparisons are—in a theoretical point of view—highly sugges¬ tive. According to M. Gustavus Rose, molten gold is of higher specific gravity than native gold.— Annales des Mines , 3me Serie, v. p. 168. Ante. p. 335, Note ||. * “At the Cliff and North American mines perfect crystals of copper occur only in the cavities of the matrix.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 173. “ The finest crystals which we have obtained were from the Cliff mine, where they are frequently thrown out with the gangue, which is generally, where the N N N 432 W. J. Henwood, on the and are encompassed by, these ample sheets and heavy masses, are interlaced with filaments, threads, and— so to speak—thick, crooked, gnarled branches, often studded with granules, scales, and crystals, # of native copper. But much as various parts of the earthy matrix may differ in composition, as long as they maintain an uniformly compact structure, the threads of metal with which they are reticulated preserve the same character. In regularly crystallized vein¬ stones, however, the copper mostly follows the faces of crystallization; f though sometimes it ramifies copper occurs crystallized, drusy quartz associated with calcareous spar. These crystals are generally tetrahexahedra; the largest which we have is one-fourth of an inch in diameter, * * * * The crystals, however, are rarely perfect, being almost always much distorted; and, often, only one or two crystalline planes are to be recognized on the extremity of a shapeless, elongated mass. We have seen, from the Cliff and Copper Falls mines, octohedral crystals, some of which were nearly an inch in diameter; cubical crystals also occur at the last named locality.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , n. p. 99. “ Les grandes masses de cuivre contiennent des noyaux de toutes dimensions, de la gangue des filons, du calcaire spathique melange avec du quartz, du feld* spath, et des fragments de trapp non altere.” Rivot, Annales des Mines, 5 me Serie, vii. p. 260. * “ But few good crystals have come into our possession, as they are highly valued by those interested in the mines, and of course difficult to be obtained.” Foster & Whitney, Report on the Geology of the Lake Superior Land District , ii. p. 99. i The miner—as well abroad as at home—considers every rare and beautiful mineral he may discover as his own peculiar privilege; and accordingly appro¬ priates it at once. Crystals of native copper, and specimens of virgin silver are, therefore, unobtainable at the mines or in the neighbouring villages; but in the collections of most English mineral-dealers, both are abundant. f “ We find copper deposited in thin plates between the joints of crystallized quartz.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , 1. p. 173. “ A compound group of twin-crystals [of copper] lay within a crystal of trans¬ parent calc-spar; the individuals of which had assumed, in reference to the main stem, the angle of the rhombohedral crystal in which they were enclosed.” Ibid , II. p, 99. Native Copper of Lake Superior. 433 through,* and occasionally it envelopes,f perfect crys¬ tals of various earthy minerals. Slickensides —some¬ times simply polished, but more frequently grooved with either straight and parallel, or curved, crooked, and divergent striae,:}:—are numerous in both the stony and the metallic ingredients. But on opposite sides of a longitudinal joint in the lode , both the character of the matrix and the disposition of the metal are often materially different; the lower, or western, portion containing the (Masses) largest bodies, the upper, or eastern, small nuggets , and particles (Barrel and Stamp-work) only; § yet Masses occupy the entire “ At the Cliff mine native copper was found impressed with crystals of prehnite, of calc spar, and of quartz.” Jackson, Report on the Geological and Mineralogical Survey of Lands in Michigan , in. p. 407. *“ We find small specks of copper enclosed in obtuse rhomboidal crystals of calc-spar, variously modified.” Foster & Whitney, Report on the Geology of the Lake Superior Land District, i, p. 173. “ Crystals of analcime occur £ % * completely filled, throughout their whole interior, with delicate ramifications of metallic copper, so that, if the silicious material were dissolved out, the form of the crystal would still be recognized by the mass of metallic matter remaining.”— Ibid, n. p. 99. t u At the Copper Falls mine * % * we find native copper deposited around crystals of analcime and calc-spar, taking the form of the faces of the crystals, every line and wave being faithfully represented, as in the electrotype process.” Ibid, i. p, 173. | Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 168. Whitney, Metallic Wealth of the United States , p. 260. Henwood, j Edinburgh New Phil. Journal, xxn. p. 161; Cornwall Geol. Trans., v. pp. 53, 172,—81; Ante, p. 13, Fig. 2. § “ In the Cliff mine, there are two combs—that attached to the foot wall containing most of the masses, while the other carries disseminated copper.” Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 172. “ The sheets of native copper, as a general thing, though not invariably, occupy the foot-wall of the vein.”— Ibid, p. 172. 434 W. J. Henwood, on the width * in some, whilst Stamp-work occurs alone in other, places. From 1848 to 1852 the different qualities of vein- stuff were obtained in the following quantities and proportions — Weights. Proportions, tons. ( Av.) Masses, estimated to contain 60 per cent, of copper, 2,103 64 .. 0*139 Barrel-work, „ 50 ,, „ 1,230*35 .. 0 081 Stamp-work, „ 5 „ „ 11,823*15 .. 0*780 Total ...... 15,157*04 •• 1* According to these estimates, the quantities and pro- “ Les petites masses sont dans la matiere argileuse rouge; les grandes Bont souvent entourees de calcaire spathique.” Rivot, Annales des Mines , 5me Serie, vii. p. 260. * “ Sheet copper often occupies the entire vein.” Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 146. “ The greatest thickness of a solid mass of copper, without seam or break, observed by us was two feet four inches. This was at the Cliff mine.” Ibid, p. 182. “ J’ai vu dans la mine des masses de plus de 2 metres (6 feet 6f inches) d’^paisseur.”—Rivot, Annales des Mines, 5me Serie, vu. p. 311. f “ The relative amount of the various kinds of mineral raised from the mine, for five years in succession, may be seen in the following table:— Years. Masses, Barrel-work, Stamp-work, estimated to contain estimated to contain estimated to contain 60 percent of copper. 50 percent, of copper. 5 percent, of copper. Totals. 1848 .. Tons (Av.) Tons (Av.) Tons (Av.) .. 1,731*87 . Tons 2,489*16 1849 .. .... 481*29 .... .. 2,493*08 . 3,227 09 3,275*60 1850 ... ... 215*32 .... .. 2^743*30 . 1851 .. .... 373*39 ... 230*12 .... .. 2,729*46 . 3,332*97 2,832*22 1852 .. .. 2,125*44 . Totals .. 1,230 35 11,823,15 15,157*04 Proportions.. 0*139 0=081 0*780 1 * Whitney, Metallic Wealth of the United States, p. 278 (Enlarged). As the navigation of Lake Superior is periodically interrupted by ice, the produce of the mines during winter, does not reach the market until the follow¬ ing summer. (Postea, p. 440.) Native Copper of Lake Superior . 435 portions of fine copper were— in the Masses .... 1,262*12 tons ( Av .).. 0’511 „ Barrel-work . 615*17 „ .. 0*249 „ Stamp-work . 591*16 „ .. 0*240 Total. 2,468*45 „ ..1. The vein-stuff extracted contained, therefore, on an average, about 0*163 its weight of copper. Some 8,270 square fathoms of the lode *—obtained, from 1845 to 1853, between the surface and a depth of (83*3 fathoms) 500 feet—afforded cru( j e me t a i. or on an a vera£nj, 1,425 lbs. of fine copper per (5,261-38 tons Av. ) S ' ° v ’ J 3 square fathom; which yielded 6,208,678lbs.f ) (2,771-73tons^.) r ffineC ° Pper; ° r ” , 751 lbs. As, however, the lode averaged no more than from fifteen to eighteen inches in width; J the portion wrought measured— cubic fms. lbs. lbs. from 1,722 92, which contained from 6,840 of crude metal, and this yielded from 3,6Q5 of fine copper, to 2,867-50, „ to 5,700 „ , „ to 8,004 „ , per fathom. * “ The remarkable and uniform richness of the vein may be inferred from the fact, that no part of it is so poor as not to be worth taking down, and so far as the work has been carried, hardly a fathom of ground has been left standing in it. On calculating the number of fathoms of the vein removed in the drifts, shafts, and stopes, I find it to be, approximately, 8,270; and there has been produced an average amount of 7G1 pounds of copper per fathom, a result which is truly astonishing, when it is considered that the whole of the vein has been taken down.”— Whitney, Metallic Wealth of the United States, p. 277. “On estime que dans toute la partie exploitee, chaque metre carr6 (10*76 square feet) de surface laterale a rendu plus de 100 kilogrammes (220 lbs. Av,) de cuivre pur.”— Rivot, Annales des Mines , 5me Serie, vn. p. 313. t Ibid, p. 278. S. T. Snow, Esq., of the Revere Copper Works, Boston, MSS. J Rivot, Annales des Mines, 5me Serie, vii. p. 277. Ante, p. 423, 436 W. J. IIenwood, on the tons. (Au.) I of cruderandal*™ 8 ' tons 5 261-38 1 otTfned f thesurface ! de P th ! 83 3 » afforded 2,771-73, or 0*5268 its weight of fine (between J l of > copper;* whilst 14,091-09 and 83-3 and 130*0, 9,231-15, „ 0-6551 ; t 19,352-47 „ the surface and 130-0, „ 12,034-81, „ 0-6219 „ The average proportions of fine copper contained in crude metal from the different depths,^: therefore, are— between the surface and a depth of 83*3 fins*. .... 1* „ 83*3 and.130*0 „ .... 1*2435. Particles, grains, and small masses of virgin-silver frequently bestud, and are imbedded in, native copper, as well as in prehnite and calcareous spar; the silver, however, is more plentiful in a metallic than in an earthy matrix, and in the shallower than in the deeper parts of the lode; yet, ultimately mixed and closely united as the metals often are, they never form an alloy .§ * Posted, p, 440. “ Pres de la surface, les masses de cuivre ont etd plus nombreuses; aux cinq- uieme et sixikme niveaux, les mosses, sont plus fortes et la proportion de mati&re u bocarder semble augmenter assez rapidement.’ , Rivot, Annales des Mines , 5me Serie, vn« p. 313. f Small quantities of crude metal were, of course, still obtained from the upper levels. I Ante, pp. 120—1, 179, 205—6, 285—6, 328—31, 383. ^ “ Native silver, more or less associated with the copper, is most abundant near the cross-course.”— Jackson, Foster, & Hill, Report on the Geological and Mineralogical Survey of Lands in Michigan , hi. p. 760. “ Two specimens [specific gravity 10*146 and 10*188 respectively] were found to contain small particles of copper scattered through them, but the copper was not alloyed with the silver. These specimens were found mixed with the vein¬ stone, associated with native copper. They were in grains from the size of a mustard-seed to pieces of more than an ounce in weight. # # # The singular fact of the occurrence of silver implanted in masses of solid copper, or dotting its surface like buttons dropped upon the copper and united by a metallic solder¬ ing or perfect metallic adhesion at the points of contact is observed in this mine, as also at the Copper Falls, Lake Superior, North American, and Northwest Companies’ mines. I have analysed hundreds of specimens without finding any true alloy of the copper and silver.”— Jackson, Ibid, hi. p, 476, Native Copper of Lake Superior . 437 Wherever the adjoining rocks are of amygdaloidal tc In a sample of the veinstone blasted from the Cliff mine % % % the silver amounted to 663*64 grains per ton [0*000042 the weight] of rock.” “ Native silver occurs by no means unfrequently, at various points of the trap range, from one extremity of the district to the other. It has, however, been found in the greatest quantity at the Phoenix (formerly Lake Superior), Cliff, Copper Falls, and Minnesota mines, * # % but is most abundant near the junction of [different rocks]. * * # The silver is often interspersed in the mass of copper, so as to form a species of porphyry, the former metal occurring in small patches and particles perfectly soldered to the enclosing mass of copper, yet, chemically speaking, entirely distinct from it. The native silver seems to occur specially in connexion with a soft greenish magnesian mineral, also with calc-spar and prehnite, and has never, so far as we know, been found distinctly crystallized, as the copper often is.”— Fosteh, & Whitney, Report on the Geology of the Lake Superior Land District , i. pp. 146, 178. “ The largest mass of silver obtained up to this time weighed more than six pounds,”— Ibid , ii. p. 108. “ The amount of silver obtained from the Cliff mine has sometimes been quite considerable. Early in the history of its operations, a great excitement was raised on the subject * % * a rich pocket of it having been met with ; but experience has uniformly shown that in the Lake Superior veins these bunches of silver are of limited extent. % Ht % The mode of occurrence of the silver is precisely similar to that of the copper; like that metal it is found only in the native state. * % % The argentiferous portion of the lodes seems to be, in general, near the plane of contact of two beds of different lithological character. “ The silver rarely forms lumps of more than a few ounces in weight, although some pieces weighing several pounds, and nearly pure, have been obtained. Unfortunately such pieces are often looked upon by the miners as their especial property, and the amount received by the companies from this source is con¬ siderably less than it ought to be, u The annexed is a statement of the amount of silver obtained at the Cliff mine; it is mostly picked out by hand from the coarse metal which is taken out from under the stamp-heads. 1846 ... 1849 ... 1847 ... 1850 ... ... 23*90 „ 1848 ... ... 81*25 „ 1851 ... ... 34*83 „ Total .... 221*39 lbs. Troy.” Whitney, Metallic Wealth of the United States, pp. 278—9. “ L’argent natif est assez abondant vers la surface, mais presque toujours assez intimement melange avec le cuivre; on n’a pas encore constate dans quelles parties du filon l’argent est plus ordinairement en forte preportion; il est dans les veines de calcaire spathique, melange de feldspath et de quartz, qui sem- blent r^pondre & la separation des bancs de trapp de texture diff£rente, mais cette loi est bien loin d’etre certaine. * * * La mine n’a pas livre plus de 438 W. J. Henwood, on the structure the lode contains copper; * but in the hard and crystalline, as well as in the soft and porous, beds, it is frequently made up of several narrow veins, and these are seldom rich.')' The more or less metalliferous vein-stones form shoots, ribands, or stripes of various qualities; which —declining from the far distant J granite,§ but co¬ inciding in position with the contiguous bands of more or less congenial amygdaloid—have, within the lode , 110 kilogrammes (294 74 lbs. Troy) d’argent en six ans de 1846 h 1851, et on ne peut pas esperer un meilleur resultat pour ravenir.” Rivot, Annales des Mines , 5me Serie, vii. pp. 311, 314. Daniel, Mining Journal , xxxv. p, 567• Ante , p. 419. * “ The most favorable rock—that in which a vein is best developed—is a granular trap, with occasional amygdules scattered through it of a lively color, and possessing a good degree of firmness.” —Foster & Whitney, Report on the Geology of the Lake Superior Land District, i. p. 170. “ The true copper-bearing rock is * * * of a fine texture, not too crystal¬ line, and with occasional amygdules scattered through it.” Whitney, Metallic Wealth of the United States , p. 258. Ante, p. 402, Note. f “ Where the vein exists in the greenstone or hard crystalline rock it is pinched ; where it enters the soft porous amygdaloid, it becomes scattered and ill-defined.— Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 170. “ Dans le greenstone on ne distingue plus de veines principales, les filons se divisent en un grand nombre de veinules.” Rivot, Annales des Mines , 5me Serie, vn. p. 251. “ Whether the rocks be granite, slate, or elvan , their hardest portions are always quartzose, and in these the lodes are seldom rich; * % * “ Where both the rocks and lodes are very soft, the lodes are usually large ; and under such circumstances they almost always split into strings, which com¬ monly consist of iron-pyrites and frequently die away in the Country .” Henwood, Cornwall Geol. Trans., v. pp. 220, 231. X Geological Map of the Lake Superior Land District , by J. W. Foster and J. D. Whitney, Rivot, Annales des Mines, 5me Serie, vii. PI. VII. § Henwood, Edinburgh New Phil. Journal , xxn, p. 157 ; Cornwall GeoU Trans, y. pp. 41, 54, 87*, 129, 193. 439 Native Copper of Lake Superior. an endlong dip,* * * § of about 28° towards the north.f The crystalline greenstone of the precipice is sepa¬ rated from the granular and amygdaloidal trap-rocks beneath by a conformable bed £ (the Slide) of chloritic conglomerate, from three to about twelve feet in thick¬ ness,—which heaves the lode about two fathoms (L.— S.A.) towards the left-hand .§ Although the works are but one hundred and thirty fathoms deep, a man-engine || has been already erected. * Henwood, Edinburgh New Phil. Journal, xxn. p. 157; Cornwall Geol. Trans, v. pp. 41, 54, 87*, 129,—93 ;— Vi. pp. 146,—94. Tregaskis, Report of the Royal Cornwall Polytechnic Society, iv. p. 96. Ante, pp. 122, 206—7,—15,—16, 224,-34,-58, 323,-6. f “ The mining ground % % % [dips towards the north] below the cliff of greenstone, in a belt of amygdaloidal trap.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, I. p. 129. “ The beds of rock dip at an angle of about 28° to the north, consequently the extent of ground in that direction * % # is increasing as each successive level extended northward from a greater depth.” Whitney, Metallic Wealth of the United States, p. 277. “ A Cliff et a South-Cliff, les masses sont abondantes et de tr&s-grandes di¬ mensions a une faible distance de la surface; elles se continuent dans la profon- deur, en formant des colonnes inelinees irregulierement vers le nord, a peu pres comme les bancs du trapp; la gangue du filon est impr^gnee de cuivre et fournit du minerai de bocard assez riche. ”-Rivot, Annales des Mines, 5me Ser., vn. p. 261. % “ Between the crystalline greenstone and the—occasionally amygdaloidal— granular trap there is a thin belt of slaty chlorite about twelve feet in thickness. % % % In the granular trap the vein is about twelve feet to the east [of its place in the greenstone] showing that it had been subjected to that amount of heave or dislocation.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District,!, pp. 127—8 (Abridged). “ At the foot of the Cliff, and separated from it by a slide—the slide of the district—lies a fine-grained trap-rock, through which run numerous and parallel belts of amygdaloid. This, with the amygdaloid and slide, dips north under the greenstone at an angle of about 28°. % * Ht The copper-ground is about 1,000 feet in length, being limited north by the slide, and dipping at the same angle with it under the greenstone.”— Daniel, Mining Journal, xxxv. p. 567. § Table XII. || “ A man-engine works in Avery’s shaft, raising the men from, and lowering them to the 100 fathom level; it is contemplated to carry the rods to the 130, when the shaft is sunk to that depth.”— Daniel, Mining Journal, xxxv, p. 56, o o o 440 W. J. Henwood, on the From 1844 to 1865 the Pittsburgh and Boston Mining Company obtained 20,359*56 tons of crude metal ,'* containing (0*6227 its weight) 12,679*37 „ of fine copper, which realized . £1,443,039 The expenditure, meanwhile, amounted to . 963,179 A net profit of .,. £479,860 * The produce of the mine and the financial operations of the Company, from 1844 to 1865, are shown in the following columns :— Years. Crude metal. Tons (Ad.) Proportion of fine copper in crude metal. Fine copper. Tons (Av.) Proceeds of copper. Expenditure Loss Profit. 1844 ■ _ - £ 639 £ 639 ... 5 14*81 0-6000 8*88 £ 618 5328 4710 — 6 48*56 0-3458 16*80 1848 13776 11928 — 7 325-82 0-5-629 183-38 14786 18626 3840 — 8 738-97 0*6020 444*85 34668 21933 — £ 12735 9 1020-11 0*5611 572-38 32339 22285 — 10054 1850 679-19 0-4697 319*04 36884 24747 — 12137 1 682-35 0-5538 377*90 36444 26588 — 9856 2 741*22 0-4995 370*25 33733 23527 — 10206 3 1010-35 0-4733 478*25 60968 38669 22299 4 1041*35 0-5639 587*19 66830 44501 — 22329 5 1337*43 0-6249 836-70 99148 53941 — 45207 6 1469-30 0*6748 991*49 111634 59687 — 51947 7 1501*59 0-7028 1055*29 31*93a | 103723 66415 — 37308 8 1421*02 0 7101 1009 12 100432 59843 — 40589 9 981*98 0*6433 631*70 60938 56703 — 4235 1860 1252*43 0-6571 822*94 72978 57561 — 15417 1 1385*55 0*6212 860*72 85102 70650 — 14452 2 1411*81 0-6340 895‘07 108320 67355 _ 40965 3 1343*99 0-6977 937*66 149818 61226 — 88592 4 944*64 0-6386 603*27 131251 85181 — 46070 5 1007*09 0*6400 644-56 100577* 83998* — 16579 Totals. 20,359-56 — 42,679*37 £1,443,039 £963*179 c £21,117 £500,977 Mean. 0*6227 Loss.... 21,117 Net Profit .. £479,860 a “ Recovered at this time from the Slags of former years.” ft Estimates. c “ By the terms of the [earlier] leases the applicant was required to * * * render to the United States six per cent, of all the ores raised.”— Whitney, Metallic Wealth of the United States, p. 248 .—“ In 1853, however, the General Law of Michigan imposed a tax of one dollar (four shillings and two pence Stg.) on each ton (2,000 lbs. Av.J of copper or mineral obtained * * * in lieu of all State taxes.” The accounts of the first nine years have been compiled from the statements of Mr. Whitney CMetallic Wealth of the United States, p. 278,) and M. Rivot ( Annales des Mines, 5me Sferie, vii. p. 313); but those of the twelve last have been prepared from particulars courteously supplied by T. M. Howe, Esq , Treasurer and Secretary of the Pittsburg and Boston Mining Company, and S. T. Snow, Esq., of the Revere Copper Company, on application from the Author’s friends, Ebenezer North Willcox, Esq., of White Woods, near Detroit, and Joseph P. Cooke, Jun., Esq., Professor of Chemistry and Mineralogy in the University of Cambridge, Massachusetts Native Copper' of Lake Superior . 441 therefore accrued to the fortunate shareholders. A comparison with these results with those obtained in other rich mines may not be deemed impertinent. The Consolidated Copper Mines , of Cobre, near Santiago de Cuba, have been worked in “ highly calcareous porphyritic rocks, passing into and associated with basalts and a peculiar conglomerate ” (Ansted, Quar. Journal of the Geological Society , xil. p. 145), with unequalled success ; of which the following particulars have been—by permission of the Directors, copied from official records. Years. Copper- ore. Tons (Aw.) Proceeds. Expenditure. Loss. Profit. 1835 . 3478 £ 63634 £ 40464 - £ 23170 6 _... 4765 80442 85709 £ 5267 7 ...... 6084 100221 96846 3375 8 . 10519 199429 117702 81727 9 . 13615 203028 166167 — 36861 1840 .. 23279 344479 221520 122959 1 . 24658 329030 256800 72239 2 . 20145 234596 223103 11493 3 . 20255 242217 212806 29411 4 . 22526 238821 223776 —— 15045 5 . 17469 193417 183092 10325 6 . 15291 163270 161234 2036 7 . 16593 191644 168632 - , 23012 8 .... 21762 217958 171847 • • 46111 9 . 19773 243291 159900 83391 1850 . 17903 229144 150504 78640 1 . 15605 217937 134677 — 83260 2 . 11078 187781 111444 76337 3 . 13090 214003 150083 63920 4 . 16530 255668 150644 ~ , 105024 5 .. 17531 271588 172784 98804 6 . 14617 217031 178713 i- 38318 7 . 13325 184151 149122 | 35029 8 . 13008 162045 135954 , 26091 9 . 13812 191796 141032 50764 1860 . 13602 183463 145784 — - 37679 1 . 13249 157037 145524 11513 2 . 11796 131519 141977 10458 3 . 14955 144728 140911 3817 4 . 13248 148261 135114 — 13147 Totals.... 453,561 £5,941,629 £4,673,865 £15,725 £1,283,489 Each ton of ore, therefore, cost on an ) ,, . ’ S £10 : 6 : 1 average $ ,, ,, was sold for 14 : 0: 0 Loss . 15,725 Net profit .. £1,267,764 For this interesting document the Author is indebted to his friend Frederick. Bankart, Esq., of the Red Jacket Copper Works, near Briton Ferry. 442 W. J. Henwood, on the Each ton of fine copper therefore cost. £ 75 19 3 Stg. and was sold for . 113 16 3 ,, The Knockmahon Mines, between Dungarvan and Tram ore, in the county of Waterford, are largely wrought by the Mining Company of Ireland, in the slate- series, near the coast, and, to some extent, beneath the sea (Weaver, Geol. Trans., o.s., v. p, 248. Oldham, Reports of the British Association for 1844, p. 221.) “ From the beginning of 1825 to the end of 1865 The Copper-ores obtained w T ere sold in Swansea for ... £1,399,232 ,, Salaries, wages, materials, &c., amounted to. £855621 ,, Royalties (Dues). ,, . 54458 „ Profits . „ . 489153 - £1,399,232 Robert Heron, Esq,., Secretary of the Company, MSS. The following particulars relate to mines in various parts of Cornwall and Devon. The Saint Just District. (Borlase, Natural History of Cornwall, pp. 101, —52,—56,—62, 206,—9. Pryce, Mineralogia Cornubiensis, p. 21. Berger, Geol. Trans., o.s., I. pp. 151,-76. Davy, Cornwall Geol. Trans., I. pp, 20—6. De Luc, Geological Travels, in., pp. 257,-60. Rashleigh, British Minerals, i. pp. 31—3. Polwhele, History of Cornwall, n. pp. 133—5. Lysons, Cornwall, p. ccvi. Hawkins, Cornwall Geol. Trans., II. pp. 29—30. Carne, Ibid, ii. pp. 87—8, 103,-10,—21,-2, 290-358; PI III. Fig. 10 ;— VII. ; Ibid, vi. pp. 28—9,47—9. Forbes, Ibid, n. pp. 175—81, 249,—55—8, PI. VI. T. F. Barham, Ibid, in. p. 151. Michel], Manual of Mineralogy, pp. 24—5, 30—2,—4,—8, 52,—8,—9, 73. De la Beche, Report on the Geology of Cornwall, &c., pp. 160,—8, 283—4, 308—9. Fox, Reports of the Cornwall Polytechnic Society, iv. pp. 86, 93. Henwood, Cormcall Geol. Trails., v. pp. 7—15, 389—90, 464, Tables I — XII., PI. I., II. Sorby, Quarterly Journal of the Geol. Soc., xiv. p. 488, PI. XIX. Fig. 118. Charles Thomas, Remarks on the Geology of Cornwall and Devon, p. 6. Salmon, Mining and Smelting Mag., i. pp. 42—5; v. p,260. Garby, Cornwall Geol. Trans., vii. pp. 75,—6, 81,—3,— 6,—7. Higgs, Ibid, vn. p. 449. Maskelyne, Proceedings of the Royal Society, xiv. p. 400.) “ Levant afforded between 1830 and 1865 a profit of rather more than £200,000, but, the particulars are now unknown, as many of the accounts were accidently burnt.”— Henry Borrow, Esq., of Truro, Purser of the Mine, MSS. At Botallack several lodes, having different directions, yield, for the most part, tin-ore whilst in granite, but copper-ores when in slate. “ From 1802 to 1836 the mine was worked by five Adventurers only, who shared amongst them a clear profit of £34,000.” Mr. Richard Wellington of Chyandour, Accountant at the Mine, MSS. Native Copper of Lake Superior. 443 The mine is still largely and profitably wrought by the original proprietary. “ From the beginning of 1836 to the end of 1865 the present Shareholders have paid for their “ plant,” and at intervals of diminished produce. £ 18,250 obtained tin-ore . which realized .. £321734 ,, copper-ores . „ .. 183011 - 504,745 and sold sundries (old materials, &c.) .. „ . 8,720 £531,715 The working expenses (salaries, wages, materials, &c.) have amounted to.. £405085 „ Royalties (Dues)... „ .. 23602 ,, Dividends, paid to the Shareholders.. ,, .. 102150 „ Balance (nominal) in the Purser’s hands .. 878 --£531,715 Stephen Harvey James, Esq., Purser of the Mine, MSS. The Saint Ives District. (Berger, Geol. Trans., o.s., i. p. 152. Forbes, Cornwall Geol. Trans., n. pp. 181—5, 259—64, Pl. V. VI. Carne, Ibid, ii. p. 344. Lysons, Cornwall, p. ccxi. Michell, Manual of Mineralogy, p. 32 ; Cornwall Geol. Trans., v. p. 19. De la Beche, Report on the Geology of Cornwall, &c., pp. 160, 283, 306,-23, 511,— 13. Henwood, Cornwall Geol. Trans., v. pp. 16—26, 390—1, 435—6, —65, Tables XIII.—XXIII., PI. II.; Ibid , vir. pp. 179—84, Table I., PI. VIII. Penberthy, Ibid, vi. pp. 106—7. Sorby, Quarterly Journal of the Geol. Soc., xiv. pp. 475,—93—4, PI. XVII. Fig. 53—6. Charles Thomas, Remarks on the Geology of Cornwall and Devon, pp. 15,19. Garby, Cornwall Geol. Trans., vn. pp. 86—9. Salmon, Mining and Smelting Magazine, in. pp. 139—48, Fig. 11—14; Ibid, v. pp. 260—1.) The Saint Ives Consolidated Mines —worked in granite, on several separate lodes, as well as on (the Carbona) an excrescent mass of vein-stone connected with one of them, afforded from 1827 to 1834 „ 1835 „ 1865 >) >> ! [ yielded 10,368 64 tons of tin-ore, which realized—at an average of £50 : 7 f 1 per ton— £522,100 the Lord’s dues, salaries, wages, and cost of ma¬ terials amounted to... . 435,597 a profit of £24,675« which left ,, 86,503 Net profit.... £111,178 Mr. John Vivian, Accountant at the Mine, Mining and Smelting Magazine , in. pp. 146—8, MSS. a The accounts for this period were accidentally burnt. 444 W. J. Henwood, on the The extraordinary richness of this comparatively In tlie Providence Mines several lodes yield copper-ores, accompanied—in one instance by a small quantity of pitch-blende,« —in the hornblendic slates ; but in the granite they as well as (the Carbona) an excrescence of rich vein-stone, adjoining the northern side of Wheal Laity north (branch) lode, afford tin-ore alone. The Capital invested from 1832 to 1848 amounted to...£11,570 From 1832 to 1865 the mines gave 4606 23 tons of tin-ore, which j av ^.ag” 0 f j : 8 : 7 per ton) realized .. £344388 9720 - 00 ,, copper-ore, „ 5:19:9 „ ,, 58220 •97 „ pitch-blende, (at from 6s. to £2 per cwt.) . 26 Sundries . 2733 - 405,367 £416,937 The salaries, wages, materials, &c. during the same period ) £310071 amounted to 5 ' ,, Royalty (Dues) . ,, ,, 14780 „ Shareholders received . ,, ,, 90020 ,, Balance in the Purser’s hands „ „ 66 -£416,937 “ The success of this Adventure may be mainly attributed to the judicious policy of the Lords,—Mr. Praed, the Basset family, Mr. Stephens, and Mr. Davies Gilbert,—in giving up their Dues for a time,* which enabled the Shareholders to prosecute the mines and bring them to their present profitable state.” General Statements, circulated amongst the Shareholders, by Samuel Higgs, Esq,., Purser of the Mines. The Gwinear District. (Hitchins, Phil. Trans., xci. (1801) pp. 159—64, PL XI, Berger, Geol. Trans., o.S., I. pp. 169, 171—7. Lysons, Cornwall, p. ccix. William Phillips, Geol. Trans., o.s., 11 . pp, 146—52,—57,—60, Pl. VI. Fig. 6,— VIII. 1, 2. De Luc, Geological Travels , in. p. 277. Hitchins & Drew, History of Cornwall, 11 . p. 556. Carne, Phil. Trans., xcvn. (1807) pp. 293—5, PI. XVIII.; Cornwall Geol. Trans., 1 . pp. 99— 102; II. pp. 105,—6,—8,—10,—13,—14,—20—4, Pl. III. Fig. 17; Ibid , hi. pp. 69, 79. Michell, Manual of Mineralogy, p. 12. Moyle, Annals of Philosophy, v. p, 36; Ibid, Yin. p. 448. Edmonds, Cornwall Geol. Trans., in. p. 332. Gregor, Ibid , p. 338. Boase, Ibid, iv. pp. 309—10,—47—8. De la Beche, Report on the Geology of Cornwall, &c., p. 306. Henwood, Proceedings of the Geological Society , 1 . p. 405 ; Cornwall Geol. Trans., v. pp. 35—42, Tables XXXIII— XLII., Pl. III. IV. Rundell, Ibid, vii. pp. 37,—8. Salmon, Quarterly Journal of the Geol. Soc., 'xvn. pp. 517—22.) a Considerable quantities of the same ore had been previously obtained at Wheal Trcnwilh, an adjoining mine.—H enwood, Cornwall Geol. Trans, v. p. 19, Note. b From March, 1840, to May, 1849, amounting altogether to about £4,000. Native Copper of Lake Superior. 445 small spot, evoked a spirit of speculation ; at least as At Wheal Alfred two lodes —having different directions, and traversing, as well the clay-slate, as the elvan intersecting it,—were wrought from 40 to 130 fathoms deep, by bottom-stopes. Between 1804 and 1815 they afforded 83,337 tons of copper-ore, which (at an average of £8 : 11 : 8 \ £*15 909 per ton) realized S 1 ' The Salaries, wages, materials, &c., amounted to .£504175 „ Royalties (Dues, one-tenth) „ ...... 71523 „ Profits shared by the Adventurers ,, . 139531 -- £715,229 From Accounts obligingly furnished by George M. Millett-Davis, Esq., of Treneere. The Alfred Consolidated Mines —which adjoin Wheal Alfred and were worked in similar rocks—yielded—from September, 1844, to February, 1861— 42,320’S tons (Avoir.) of copper-ore which (averaging ) £6 : 18 : 1 + per ton) > £292262 realized . ) blende, which realized . 719 lead-ore ,, . 115 tin-stone ,, ...... 56 - £293,152 The Salaries, wages, materials, &c.,. amounted to £179000 ,, Royalties (Dues) . ,, 16104 ,, Profits divided amongst the Shareholders ,, 98048 - £293,152 For this Account,—prepared by Mr. T. W. Robinson, Purser of the Mine,—- the Author is indebted to Mr. J. Sampson Courtney, of Poltair. At Godolphin (Bridge) the copper-ores,—obtained, within ninety fathoms of the surface, from different parts of one lode , in the slate-formation,—afforded, early in the present century, a net profit of £66,000. William Williams, Esq., of Tregullow, MSS. The Helston District. (Carew, Survey of Cornwall , pp. 13,153. Borlase, Natural History of Cornwall, p. 161. Jars, Voyages Metallurgiques , ill. p, 194. Klaproth, Mineralogical Observations, p. 31. De Luc, Geological Travels , 111 , pp. 270,— 3. Hitchins & Drew, History of Cornwall, 11 . p. 116. C. S. Gilbert, Historical Survey of Cornwall, 11 . p. 760. Sedgwick, Cambridge Phil. Trans, T. pp. Ill—14,—29. Came, Cornwall Geol. Trans., 1 . p. 102; Ibid, II. pp. 66 — 119; Ibid, ill. p. 77. Fox, Ibid , II. PI. II.; Ibid , hi. p. 318; Phil. Trans., cxx. pp. 407,—11. Hawkins, Cornwall Geol. Trans., II. pp. 31, 380. Forbes, Ibid, II. pp. 185—9. T. F. Barham, Ibid, hi. p. 151. Michell, Manual of Mineralogy , p. 71. Moyle, Cornwall Geol. Trans., 11 . pp. 406,—11; Annals of Philosophy, vi. p. 90. Von Oeynhausen & von Dechen, Phil. Mag. 8$ Annals, v. pp. 243,—6. Boase, Cornwall Geol. Trans., iv. pp. 348—55; Primary Geology, p. 56. Richard 440 W. J. Hen wood , on the fierce and indiscriminating as that too frequently Thomas, Mining Review, ill. p. 30. De la Beche, Report on the Geology of Cornwall, &c., pp. 162,—62,—71,—5, 284, 307,—28,—41. Henwood, Edinburgh New Phil. Journal, xxii. p. 154; Cornwall Geol. Trans., v. pp. 43—56, 394, 467—8, Tables XLIII.-- XLV1II., PL V.; Reports of the Royal Institution of Cornwall, xli. pp. 22—3 ; Annales des Mines, 5me Serie, xvi. pp. 571—3. Charles Thomas, Remarks on the Geology of Corn- icall and Devon, pp. 2,15, 16, 19, 21,-2,-3. Salmon, Mining and Smelting Magazine, II. pp. 14—18, 84 —7 ; Ibid, v. pp. 287, 328.) Wheal Vor —for many years the richest tin-mine in Cornwall—was worked mostly in slate, but to some extent in the granite also. The principal opera¬ tions were confined to one lode ; but other lodes, as well as metalliferous floors, ■which extended from one of them to another, were likewise wrought, The mine, which had been worked, at least twice, before, was reopened in 1810, and prosecuted without interruption until 1847. As late as 1850, indeed, the (leavings') poorer ores, previously brought to the surface, were still (dressed) treated with advantage. “From 1822 to 1850 the profit, divided amongst the shareholders amounted to £119,346.”— John Kendall, Esq., Banker of the Company, MSS. In 1853 operations were resumed; but in 1860 the deeper works were once more abandoned. At Wheal Metal immediately south, however, a parallel lode still yields great profit. During the thirteen years 1853—1865, the mine has afforded 5167*3 tons of tin-ore, which (at an average of £68:15 : 6 ) £355337 per ton have realized.. f *' To March, 1860, the loss amounted to ... 194326 - £549,713 The Salaries, wages, materials, &c., have amounted to.. £471029 „ Royalties (Dues) . „ .. 18110 „ Profit from March, 1860, ) ZQZ7A. to December, 1865.... * . ” ** 0J0/ * - £549,713 George Noakes, Esq., F.G.S., Chairman of the Company, & Mr. William Argall, Accountant at the Mine, MSS. The Camborne and Illogan District. (Borlase, Natural History of Corn¬ wall, pp. 168—70, PI. XVIII. Fig. 1, 2. Pryce, Mineralogia Cornubi- ensis, pp. 170—2, PI. IV. Jars, Voyages MHallurgiques, hi. p. 221. Klaproth, Mineralogical Observations, pp. 27, 31, 61—6. Warner, Tour through Cornwall,-pp. 131—5. Berger, Geol. Trans., o.s., 1 . pp. 146,—54,—66,—70. De Luc, Geological Travels, in. pp. 286—94. William Phillips, Geol. Trans., o.s., n. pp. 152—5, PI. VII. Fig. 2; Phil. Mag . § Annals, II. p. 286. Rule, Cornwall Geol. Trans., 1 . p. 225; Ibid, yii. pp. 161—3. Lysons, Cornwall, p. ccix. Hitchins & Drew, History of Cornwall, 11 . p. 140. Richard Thomas, Survey of the Mining District from Chasewater to Camborne, pp. 30—77. 447 Native Copper of Lake Superior. displayed in this country under the like circum Sedgwick, Cambridge Phil. Trans, t. p. 122. Carne, Cornwall Geol. Trans., n. pp. 95—9, 102—5, PI II. Fig. 9,— III. Fig. 16; Ibid, ill. p. 84. Forbes, Ibid, II. pp. 189—91. Hawkins, Ibid, pp. 376—82; Ibid, iv., p. 6. Pendarves, Ibid, hi. pp. 333—4. Michell, Manual of Mineralogy, pp. 20, 35—6, 52. Faraday, Phil. Mag. § Annals, ii. p. 287. Fox, Cornwall Geol. Trans., n. pp. 20,—3, PI. I.; Ibid, III. pp. 318,—19,—23,—7 ; Phil. Trans., cxx. pp. 404,—10,—11,-— 12; Reports of the Cornwall Polytechnic Society, iy. pp, 85,—91— 2; Ibid, xiv. pp. 1—3; Reports of the British Association, 1834, p. 572;—1837, pp. 135—7;—1840, pp. 309—19 1857, pp. 96—101. Boase, Cornwall Geol. Trans., iv. pp. 311—12; Primary Geology , pp. 184, — 90. De la Beche, Report on the Geology of Cornwall, &c., pp. 176, 288, 306,-24, PI. VII., VIII., IX. Henwood, Phil. Mag. $ Annals, x. p. 360; Reports of the British Association, vi. 1837, p. 74 ; Cornwall Geol. Trans., v, pp. 57—68, 395—6, 432—4,—68—9, Tables XLIX.— LVII., PI. V., VI., VI *; Proceedings of the Royal Society, iv. p. 317; Reports of the Royal Institution of Cornwall, xli. pp. 22—3 ; Annales des Mines, 5me Serie, xvi. pp. 571—3. Leifchild, Encyclopedia Britannica, xv. pp. 223—4. Sorby, Quarterly Journal of the Geol Soc., xiv. p. 474. Gar by, Cornwall Geol. Trans., vi. pp. 194—5; Ibid, vn. pp. 73—4, 82—92, Charles Thomas, Remarks on the Geology of Cornwall and Devon, p. 6, PI. I., II., III. Pearce, Reports of the Royal Institution of Cornwall, xliii. p. 35. Salmon, Mining and Smelting Magazine, I. pp. 46—7, 316—18,—84 —8, PI. V.; Ibid, II. pp. 74—8, 300—1; Ibid, in. pp. 82—9; Ibid, v. p. 329. Matthews, Ibid, n. p. 337, Report of Commissioners on Mines in Great Britain (Appendix B) Sections of Condurrow and East Pool.) Dolcoath has been worked—with but one short interval—from beyond memory to the present time,—in both the granite and slate, as well as in the elvan (felspathic and quartzose porphyry) intersecting them,—on several lodes ; which have yielded native silver (Ante, pp. 112—13), together with several ores of silver, nickel, and cobalt; but have afforded, and yet continue to afford, the ores of copper and tin in much greater abundance. Dates. Value of ores sold. Royalty (Dues) paid. Profits divided. Calls. From June 1800, to end of 1819.. £1,285,575 £54,343 £92,636 -j „ end of 1819 „ Apr. 1835.. 767,282 32,236 61,390 Neither divi- ^ £45,252 „ April, 1835 „ Oct. 1849.. 289,665 Dues given up dends nor calls „ Oct. 1849 „ end of 1865.. 745,310 32,776 145,039 Totals. £3,087,832 £119,355 £299.065 Calls . 45,252 Net Profit.. £253,813 Amount of Royalty (Dues) given up by the Lords.... £28,347. “ A tradition remains that in 1788 (Ante, p. 146, Note) the aggregate produce. P P P 448 W. J. Henwood, on the stances. For—with little regard to the characters of —mostly of copper-ore,—had already realized tioo millions Sterling; but in that year the Adventurers—believing they had extracted everything worth removal— abandoned the mine; which had reached a depth of 185 fathoms. In 1800, however, operations were resumed ; and—with the aforegoing results—they have been continued until now (1866).” Captain Charles Thomas, Manager and Purser of the Mine, MSS. Mr. Pryce’s section of the works (Mineralogia Cornubiensis, PI. IV.) pub¬ lished in 1778, shows a depth of rather less than 90 fathoms. His Prospectus (of which a copy—perhaps the only one remaining—is in the Author’s possession) states, however, that “ it is now three and twenty years since [he] first attended the transactions of the most capital copper mine (Dol-Coath or Bullen-Garden) in this county, which [he] was authorized to do by holding a small part in it; # % % during which time [he] made such enquiries and observations, as fur¬ nished a large share of the present materials. By so doing in two or three years they increased on [his] hands : [he] had therefore no better method to pursue, than to throw them into the form of a book.” It would seem, from this, that the section was made about 1758. Mr. Buie’s well-known section—published (PI. VIII.) in Mr. De la Beche’s Report on the Geology of Cornwall, Devon, and West Somerset —was prepared in 1824, when the mine had reached a depth of nearly 240 fathoms. From (?) 1758 to 1788, therefore, the works had been deepened (by bottom-stopesa ) 95fms.; and ,, 1800 ,, 1824, ,, ,, ( ,, shafts') 55 ,, • They are now 340 fathoms deep. The Cam Brea Mines yield the ores of tin and copper, on several lodes, which are wrought in the granite and slate formations, as well as in the elvan-courses which are common to both. In the course of thirty-one years (1834—1864) the shareholders have realized profits, which—varying from £2,000 to £20,000 per annum,—have amounted to £273,500. “ The cost of acquisition of the mines, and the expenses of working, up to the payment of Dividend, was £15,000. “ Besides the Dividends paid, the Mines’ produce created the plant,” now valued, as if to be broken up, at £40,000, but which must have cost nearer £100,000.” Thirty-fifth Report of the Directors; presented at the Yearly Meeting of the Adventurers , 27th May, 1865. For this document the Author is indebted to R. H. Pike, Esq., Purser of the Mines. North Roshear and Wheal Crofty are prosecuted, on different lodes , in rocks composed chiefly of felspar and hornblende; irregularly sprinkled with quartz, and—at times—with calcareous matter. Early in the last century a profit of about £45,000 was made from copper- ores obtained at shallow levels towards the east. a Pryce, Mineral. Cornub., p. 101. Carne, Cornwall Gcol. Trans., in. p. 69. Rule, Ante, p. 146, Note. Native Copper of Lake Superior. 449 the lodes —and the nature of the rocks,—mines were From the beginning of 1818 to the end of 1853 the mines have afforded— tons C (sold at an 142,953*8 of copper-ore which ] average ( price of 144*2 „ tin-ore „ „ 26*1 „ blende ,, ,, 330 8 ,, arsenic ,, ,, Sundries (old materials, &c.) sold . Calls, at intervals of diminished produce per ton £5 18 7) realized £847,808 44 6 8 ) „ 6,395 2 7 11) „ 63 2 13 4) „ 884 £855,150 4,100 11,200 The salaries, wages, materials, and ether ) am0Knted t0 £717 393 working expenses .J ’ £870,450 ,, Royalties (Dues) ... ,, ,, Dividends shared amongst the Adventurers „ 52,378 100,679 £870,450 William Cock Vivian, Esq., Manager of the Mines, MSS. West Wheal Seton has been worked from 1844 until now (1866) in an elvan- course, seen underground in Wheal Seton and at the surface in Worth Roskear , as well as in the same slate-rocks, and on the same lodes , as East Wheal Crofty, Wheal Crofty , and Wheal Seton , with the following results;— Proceeds of tin and copper ores sold.. £454,836 Amount of salaries, wages, &c.£186,768 „ Machinery and materials. 79,418 -£266,186 Royalty (Dues) paid the Landowner. 30,322 Profit divided amongst the Adventurers. 158,328 •-£454,836 “ The Plant is worth at least £5,000.” ——- Benjamin Matthews, Esq,, of Saint Day, Purser of the Mine, MSS. West Wheal Basset, in the granite of Cam Kye, has been largely wrought on four—and less extensively on several other— lodes, with the undermentioned results. In 1850—2 the outlay amounted to .. £9,000 From January, 1850, to March, 1856, the mine yielded tons {Av.) per ton 78,216 of copper-ore, which (averaging £6 1 11+) realized £476,838 26 „ tin-ore, „ ,, 55 13 4+) „ 1,464 tin-stone, „ .. „ 7,202 Sundries (old materials, &c.) .... ,, 1,471 - 486,975 The payments for Salaries, Wages, &c., amounted to ,, Machinery, tools, & materials „ ,, Royalty (Dues) .. „ ,, Sundries (Rates, taxes, &c. . ,, £495,975 .... £210,598 . • •. 77,559 .... 31,233 . •.. 8,357 Carried forward £327,747 450 W. J. Henwood, on the opened on all sides. Within twenty years more Brought forward The Profits divided amongst the j ha¥ebeen- . Adventurers . > Costs of Law-suits with the Shareholders in an adjoin¬ ing mine -... Balance of Cash in the Treasurer’s hands > amounted to .$ £159,600 7,621 1,007 £327,747 168,228 -£495,975 The Redruth and Gwennap District. (Borlase, Natural History of Corn¬ wall, pp. 174, 205. Pryce, Mineralogia Cornubiensis, pp. 33, 192, 231, — 80, PI. VII. Jars, Voyages MHallurgiques , in. pp. 192 — 4. Klaproth, Mineralogical Observations , pp. 8 , 10, 25 — 8 , 30, 59. Maton, Observa¬ tions on the Western Counties , I. pp. 242—8. Thomson, Annals of Philosophy, ii. p. 350. De Bournon, Phil. Trans., xci. p. 169. Chenevix, Ibid , xci. p. 193. Gregor, Ibid, xcix. p. 195, Warner, Tour through Cornwall , pp. 176, — 90. Berger, Geol. Trans., o.s., i. pp. 146, — 62 — 6 , — 70 — 7. De Luc, Geological Travels, hi., p. 325. William Phillips, Geol. Trans., o.s., n. pp. 155 — 6 , PL VI., Fig. 1. Smith, Ibid, iv. p. 58. Williams, Ibid, pp. 142—5, PL VI., Fig. 1. Hitchins & Drew, History of Cornwall, II. p. 305. Richard Thomas, Survey of the Mining District between Chasewater to Camborne, pp. 5—76 ; History of Falmouth, pp. 31 — 3. Rees, Cyclopaedia, xxm., Article Mining, Carne, Cornwall Geol. Trans., I. p. 103 ; n. pp. 76 — 9, 82—90, 121; in. pp. 65,—7, 74,—7,—9, 81,—3,—4. Fox, Ibid , II. pp. 20—1,—5, Pl.I.; iii. pp. 314—17,—24— 6 ; Phil. Trans., cxx. pp. 401,—7,—10,—11,—13,—14; Reports of the Cornwall Poly¬ technic Society, iv. pp. 90— 6 , 124; xiv. p. 1; Reports of the British Association, 1834, p. 572; 1837, p. 135; 1840, p. 309; 1857, p. 96. Sedgwick, Annals of Philosophy, ix. p. 249. Moyle, Cornwall Geol. Trans., n. pp. 205— 6 . Boase, Ibid, rv. pp. 290—2, 304—7 ; Primary Geology, pp. 181,—5,— 8 . Bennetts, Phil. Mag. % Annals, in. pp. 17 -18. Burr, Practical Geology, pp. 286— 8 , PI. IV. V. ; Mining Review, III. pp. 226,—32. De la Beclie, Geology of Cornwall, S$c., pp. 176— 7, 305—7,—10,—24,—9,—33,—7,—40, 404. Henwood, Proceedings of the Geological Society i. pp. 405— 6 ; Cornwall Geol. Tracis., in. pp. 203—7, 329—31 ; iv. pp. 57—60; v. pp. 69—92*, 396—9, 417—26,— 32-4,-70—1, Tables L VIII. — LXIX., PL VII., VIII. Michell, Manual of Mineralogy, pp. 27—40, 52, 63, 85; Cornwall Geol. Trans., in. p. 338. Evan Hopkins, Connexion of Geology with Terrestrial Magnetism, p. 50, PL VIII. Francis, Gwennap, pp. 4, 11, 21, 38, 63, 94. (Captain) William Francis, Reports of the Cornioall Polytechnic Society, xiv. p. 4. Sorby, Quarterly Journal of the Geol. Soc., xiv. pp. 485—6,-92—4, PI, XIX., Fig. 107-8-9. Garby, Cornwall Geol. Native Copper of Lake Superior . 451 than one hundred Companies were organized for Trans ., vi. p. 265; vn. pp. 73—5, 81—92. Charles Thomas, Remarks on the Geology of Cornwall and Devon, pp. 4, 14,16, 20,—2. Salmon, Mining and Smelting Magazine , i. p. 316; ii. pp. 140—8 ; v. p. 328. Smyth, Ibid, v. pp, 193—6; Reports of the British Association, 1864, Part ii. p. 70. Lyell, Ibid, p. lxv. Miller, Ibid y Part n. p 35. Pearce, Journal of the Royal Institution of Cornwall , i. p. 53. Report of Com¬ missioners on Mines in Great Britain , Appendix B, Section of Workings in Poldice (St. Day United Mines). Ante, p. 114.) At Wheal Buller , one of the lodes , wrought in granite, from July, 1849, to May, 1861, yielded— tons per ton 82,609*4 of copper-ore, which (averaging £5 15 8-f-) realized £477,886 621*8 ,, tin-ore, ,, „ 69 9 2-f-) „ 43,180 beside tin- (stuff) stone „ . „ 2,235 -:— £523,301 The Royalties (Dues, for great part of the time l-16th, ) but towards the last l-30th of the produce), together > £279,909 with the salaries, wages, materials, &c., amounted to ) „ Profit divided amongst the Shareholders ,, .. 243,392 -£523,301 Richard Davey, Esq., M.P., F.G.S., of Bochym, MSS. Tresavean —wrought in granite on a single lode —yielded, from the beginning of 1828 to October, 1838, copper-ores which realized.. £720,338 The Salaries, wages, materials, and other working costs,) Qnq meanwhile, amounted to ) ’ 19 19 19 Royalty (Dues) . Profit shared amongst the =j Adventurers ... ’ Balance remaining in the | Purser’s hands .. >> 99 11 36,331 348,456 9,348 £720,338 Mr. Hugh Phillips, Accountant at the Mine, Cornwall Geol. Trans., v. p. 88*. The granite of Carn Marth, the slate on its northern, eastern, and southern slopes, and the elvan-courses common to both, are alike traversed by many lodes ; which yield, generally, tin-ore near the surface, but copper-ores at greater depths. The following list of profits made in the neighbourhood from 1800 to 1840 has been compiled from the books of the respective mines; all which have since been abandoned. Mines. Rocks. Wheal Damsel . Granite ... Wheal Jewel . „ ... Wheal Gorland . ,, . Treskerby .. Granite, slate, and elvan Ting Tang . .. Slate and elvan . Wheal Maid . Slate .... Profits. £250,000 400,000 60,000 105,000 42,000 200,000 £1,057,000 Sir William Williams, Bart., of Tregullow, MSS. QQQ 452 W. J. Henwood, on the working copper-mines on the shores of Lake Superior. The Consolidated Mines have been worked in the clay-slate and in the elvans which traverse it ; on several lodes , consisting chiefly of quartz; mixed, near the surface, however, with tin-ore and the rarer compounds of copper; but, at greater depths, with copper-pyrites only. The cost of bringing the mines into profitable condition amounted to ... In twenty-one years (1819—1840), however, they yielded— $ £ 65,000 tons per ton 299,184 8 of copper-ore, which (averaging £7 0 4+) realized 2,099,485 At the end of that term the Plant , stores, &c. ,, 90,000 -£2,254,485 During the same period, the Salaries, wages, \ amounted t0 £1 611 290 and Materials $ } 9 >> a Royalties (Dues) „ Sundries (expenditure at ) the United Mines, &c.) j >» Dividends shared amongst ) the Adventurers.} >> 87,153 75,886 480,156 -£2,254,485 Compiled from Accounts of the Mines, by Henry Thomas, Esq., F.G.S., of London. At Wheal Unity —worked late in the last, and early in the present, century— in the slate series immediately east of, and on the same copper-Zotfes as, Wheal Gorland , the Adventurers shared a net profit of...... £370,000 beside maintaining operations on parallel ti n-lodes in rocks of the') same system at Poldice; an adjoining mine, wrought, at the same V 130,000 time by the same parties, at a loss of nearly. \ The total profit at Wheal Unity , therefore, approached half a million Sterling. Richard Dayey, Esq., M.P., F.G.S., of Bochym, MSS. Between Carnon and Point —near the head of Restronguet-creek a navigable branch of Falmouth harbour—a rich and extensive deposit of (detrital) stream- tin-ore has been wrought, at intervals, for great part of a century. The earlier works— protected, as well from the river as the tide, by a strong embankment, and open to the day«—were abandoned in 1811—12, after having yielded a profit & of rather more than £50,000. Mr. William Trebilcock, (of Car barrack), an Accountant at the Works, MSS. In 1824—5 a shaft was sunk immediately north of the creek; and (galleries) levels —which at one and the same time grazed the (shelf) slate beneath, traversed a “ For removing the overburthen, of mud, sand, and gravel, the workmen received two shillings and tenpence per cubic fathom.”—M r. William Trebilcock, MSS. b “ The Carnon Stream Works * * * are nearly a mile in length and three hundred yards in breadth. The number of men and boys employed amounted to at least one hundred and fifty; * * * the proprietors gaining at least three thousand pounds per annum.” Maton, Observations on the Western Counties (1794—6), I. p. 174. Native Copper of Lake Superior. 4 53 Of these, however, great numbers have been from the tin-ground, and skirted the overlying beds a—were extended towards the south. This experiment afforded, in two or three years, a profit of £28,000. Mr. Edmund Michell, of Tresavean, a Shareholder, MSS. Operations were resumed in 1833, but so far down the inlet that, even at low- water, the surface was never dry. Through a mound of rubbish, purposely heaped up in mid-channel, an iron-bound shaft was opened to the ore; and in levels, extended on all sides, people worked day and night, whilst ships passed and re-passed overhead. In 1843 the undertaking was abandoned. The entire produce realized . £52,615 ,, Working expenses amounted to about . £65,692 ,, Royalties (Dues) ... . 2,923 - 68,615 A loss was therefore incurred of some .... £16,000 Mr. Nicholas Sampson Cloak, Accountant at the Mine, MSS. The Saint Agnes and Perran-zabuloe District. (Tonkin, Notes to Carew's Sxirvey of Cornwall —Lord De Dunstanville’s Edition, pp. 33—4,—6. Borlase, Natural History of Cornwall, pp. 76, 110,—65,—88, & 207. Pryce, Mineralogia Cornubiensis , pp. 20, 58, 84, 107. Klaproth, Min¬ eral ogical Observations , pp. 7, 9, 21, 58. Warner, Tour in Cornwall , p. 291. Maton, Observations on the Western Counties, I. pp. 248—54. Berger, Geol. Trans, o.s., i pp. 155,— 62,—64,—71. Gregor, Annals of Philosophy , o.s., vin. p. 277. William Phillips, Geol Trans , o.s., iv. pp. 129—37; PI. VII. Fig , 8. Lysons, Cornwall, pp. ccv.,—vm. Polwhele, History of Cornwall , iv. pp. 133—4. Conybeare, Geol, Trans., o.s , iv. pp. 401—3 ; PI. XXIII. Fig. 2, 3. Hitchins & Drew, History of Cornwall, n. p. 18. C. S. Gilbert, Historical Survey of Cornwall , I. pp. 219,— 59. Rashleigh, British Minerals , i. pp. 6, 9— 13, 38, 40,—8,50; n. p. 19. Sedgwick, Cambridge Phil. Trans., i. pp. 131—2. Carne, Cornwall Geol. Trans., i. pp. 120—21; n. pp. a Similar operations, on a small lateral extension of the same deposit below Perran Wharf, permitted the decomposition of incumbent vegetable matter, and the consequent escape of in¬ flammable gas; of which explosions sometimes scorched the workmen. b “ The richest tin-mine I have ever heard of, as to the quality of the ore, is one in the parish of St. Agnes * * * called Polberou. Several parallel and contiguous veins, mostly of large- grain crystals, make the treasure of tin in such quantity, that, in the year 1750, they could not get horses enough to carry the tin from the mine to the melting-house, but carried it in ploughs” (wains drawn by oxen), “ a very unusual sight (though doubtless a more effectual and easy draught, where the ways will admit of wheels. Great part of the ore was so rich that it needed not to be stamped, and the lode was so large that it afforded vast rocks of tin; one rock, in March, 1750, was brought to Killinick melting-house near Truro, which weighed 664 pounds, and it brought 11J for 20, in the stone; [another] weighed 1,200 pounds. It has been judged that the Jate Mr. Denithorne, who had the whole adventure, and worked it at his sole expense, in a few years last past, got at least £40,000 clear by the mine.” Borlase, Natural History, p. 188. 454 W. J. Henwood, on the time to time abandoned, after short—and, perhaps, 55, 74, 80,—6—92,—4—5,—7, 103,—4,—8,—11—18,—20,—6—7; hi. pp. 69, 77, 229. John Miehell, Manual of Mineralogy , pp. 9, 11, 12, 19, 20,—5, 32,—7, 61—2,73, 85. Hawkins, Cornwall Geol. Trans., hi. p. 11. Fox. Phil. Trans., cxx. pp. 401,—11,—13 ; Cornwall Geol. Trans., in. p. 314. von Oeynhausen & von Dechen, Phil. Mag. 8$ Annals , v. pp. 169—70. Boase, Cornwall Geol. Trans., iv. pp. 293—304,—97 —405; Primary Geology, pp. 169,—87. Be la Beche, Report on the Geology of Cornwall, &c„ pp. 162,—77—8, 283,—4,—8, 305,—16,— 17. — 27, — 36, 511. Sedgwick & Murchison, Geol. Trans., N.S., v. pp. 667—8. Davey, Cornwall Geol. Trans., iv. pp. 484—5. Henwood, Proceedings of the Geol . Soc., I. p. 405 , Reports of the British Asso¬ ciation, vi. Part n. p. 74; Edinburgh New Phil. Journal, xxii. p, 155 ; Cornwall Geol. Trans., v. pp, 93—114, 399—400,—72—3, Tables LXX. — LXXXI1I. PI. IX. Fig. 1—9; Reports of the Royal Institution of Cornwall, xxv. pp. 54—6. Whitley, Ibid, pp. 34—7. Richard Thomas, Mining Revieic, n. pp. 265—74 ; Cornwall Geol. Trans, v. pp. 98, 111 —12. Robert Miehell, Ibid, p. 268. Williams, Ibid, vi. p. 131. Tweedy, Reports of the Royal Institution of Cornioall, xxi. p. 44. Haslam, Perran-zabuloe, pp. 40—1. Garby, Cornwall Geol. Trans., vii. pp. 76—9, 81—8, 21—2. Smyth, Ibid, pp. 332—5. Arundell, Pick # Gad, I. pp. 2, 51—4, 111. Charles Thomas, Remarks on the Geology of Cornioall and Devon, pp. 19, 20. Pearce, Reports of the Royal Institution of Cornwall, xliii. p. 34. Blight, Churches of West Cornwall, pp. 89—90. Ante, pp. 110—-11.) Wheal Towan —worked until 1815, in slate, and mostly on one lode —yielded a profit of £127,000; of which the late R, A. Daniel, Esq., of Trelissick in Feock, received three-quarters. Captain Nicholas Vivian —sometime Manager of the Mine—MSS. East Wheal Rose —wrought in clay-slate—yielded, between June, 1834, and April, 1855, lead and silver ores which realized... .... £799,588 The Salaries, wages, materials, &c., amounted to. £471,850 ,, Royalties (Dues) . ,, . 53,178 „ Profit (ranging from £2,944 to £52,928 per annum 5,944 i • • • • 5 ff 274,560 £799,588 Edward Michell, Esq., of Mitchell Hill, near Truro, Purser of the Mine, MSS. The St. Austell District. (Borlase, Natural History of Cornwall, pp. 96, 151,—62—3,—89, a 214. Pryce, Mineralogia Cornubiensis, pp. 32, 68, a “ The mine which has turned out the most gain, and the greatest quantity of tin yet known, is * Polgooth’ in the parish of St. Mewan, where it appears by the old books, that the adven¬ turers have got £20,000 annually for a great number of years following.”— Letter from Mb. W. Roswarn of Truro, Feb. 11, 1756. Borlasb, Natural History, p. 189. 455 Native Copper of Lake Superior. insufficient-trial; although many are still wrought 123. Jars, Voyages Metallurgigues , hi. pp. 108, — 90. Klaproth, Mineralogical Observations, pp. 10, 13. Warner, Tour in Cornwall, pp. 96—102. Polwhele, History of Cornwall, hi p. 10; iv. pp 133-5. Thomson, Annals of Philosophy, n. p. 347* Gregor, Phil, Trans., xcv. p. 331; Cornwall Geol. Trans., i. p.224. Maton, Observations on the Western Counties, I. pp. 151—69. Rashleigh, British Minerals, i. pp. 1—8, 11, 17, 48; ii. p. 20, PI. XX/.; Cornwall Geol. Trans., ii. pp. 281—4. Berger, Geol. Trans , o.s., i. pp. 125,—62,—9,—79. Heron de Villefosse, Richesse Mineral, n. p. 354. De Luc, Minera¬ logical Travels, in. pp. 339—49, Lysons, Cornwall, pp. ccv„—xi. PI. II. Sedgwick, Cambridge Phil. Trans., I. pp. 104—5,—8; Pro¬ ceedings of the Geol, Soc., i. p. 283 ; Phil. Mag. <5f Annals, ix. p. 284; Quarterly Journal of the Geol. Soc,, yiii. pp. 9—11; Geol. Trans., N.#, III. pp. 482—4. Smith, Geol. Trans, o.s., iv. pp. 404—8. Hitchins & Drew, History of Cornwall , ii. pp. 61—71. C. S. Gilbert, Historical Survey of Cornwall, I. pp. 219,— 27,—48. Haw-kins, Cornwall Geol. Trans., i. pp. 143—53, PI. V.; ii. pp. 285—9; iv. pp. 475—80. Majendie, Ibid, i. p. 237. Carne, Ibid, ii. pp. 87—9, 90—4, 103—7, —11,—18,—27. Michell, Manual of Mineralogy, pp. 21,—5,—8,39, 50—1, 62—4, 71,—3, 82,—5. Davis, Mining Review, iv. p. 111. von Oeynhausen & vonDechen, Phil. Mag, Annals, v. pp. 241-3. Colenso, Cornwall Geol. Trans., iv. pp. 21—30, PI. I. Boase, Ibid, pp. 235— 52, — 80 — 1, 379 — 82, 404; Lond. Edin. § Dublin Phil. Mag., vii. pp. 379, 450 ; x. p. 350. De la Beche, Report on the Geology of Cornwall, &c., pp. 81—3, 159—60,—81—3,—5 —9, 284,-8, 302-5,-10,-27 —9,—32,—4,—46—7,—67, 401—3, 501,-61—2, 603—5, PI. X. XI. Sedgwick & Murchison, Geol. Trans., n,s,, v. pp. 664—9. Winn, Reports of the Royal Institution of Cornwall, xxi. Henwood, Edin. New Phil. Journal, xxn. pp. 54,—6 ; Reports of the Royal Institution of Cornwall, xxi. pp. 54—6; Cornwall Geol. Trans., iv. pp, 60—4; v. pp. 115—30, 400,—74. Richd. Taylor, Ibid, vi. p. 99. David Williams, Ibid, pp. 334—6. Stocker, Reports of the Cornwall Polytechnic Society, xx. pp. 77—96. Sorby, Quarterly Journal of the Geol. Soc., xiv. pp. 86—7, 492—4, PI. XIX. Fig. 111,-17,-19. Charles Thomas, Re¬ marks on the Geology of Cornwall and Devon, pp. 16, 20—1. Arundell, Pick § Gad, 1 , pp. 2, 53, 108—9. Pearce, Reports of the Royal Insti- Uition of Cornwall, xliii. p. 35; Journal of the Royal Institution of Cornwall, 1 . p. 224. R. H. Williams, Reports of the Royal Institution of Cornwall, xxxix. p. 32; xlv. pp. 44—7, PI. V.; Salmon, Mining and Smelting Magazine, v. p. 330; Maskelyne, Proceedings of the Royal Society, xiv. pp. 86—9, 392—400. Ante, p. 118.) The Crennis lode —which was wrought in clay-slate, immediately beneath certain long-known fossiliferous strata,—afforded in R R R 456 W. J. Henwood, on the with reasonable prospects of success. But, amongst fms. 1811, atpess than 14 from the surface. , tons | 2,136-4 of copper-ore, per ton which (averaging £9 8 9) realized £20,132 1812, when the ) 0 mine was j deep, 10,109-3 99 99 8 8 7) 99 53,139 1818, „ 34 9 9 6,304-5 99 99 6 19 9) 99 70,300 1814, „ 88 1815, „ 50 1816, (6 months) „ 99 10.551-2 99 9 9 9 1 4) 99 95,679 99 7,160 6 99 99 5 17 9) 99 42,145 99 2,985-8 99 99 5 14 8) 99 17,121 39,247,8 „ „ £7 12 1 + ) „ £298516 The profit was about £120,000. Wood (Hitciiins & Drew’s), History of Cornwall , ii. p. 70 (Abstract). Whilst the Property-tax (of ten per cent.) continued, the Hues were (1-8 & 1-80) eleven-eightieths, but on its abolition (in 1814) they were reduced to one- eighth, of the produce.— William Pethericic, Esq., of St. Austell, MSS. The Foioey Consolidated Mines have been worked from 1815 until now (1866) on many lodes , in clay-slate, alternating, here and there, with thin beds of mas¬ sive felspar. From 1815 to 1842 they afforded tons per ton 234.486'4 of copper-ore, which (averaging about £6 1 4) realized.. £1,422,634 The Landlords received as Royalties (Dues) .£95,611 ,, „ for damage to the surface.. 2,436 - £98,047 ,, Machinery, materials, &c., cost,... 237,706 ,, Salaries, wages, &c, amounted to. £902,191 ,, Medical attendance cost. 4,694 - 906,885 ,, Profits divided amongst the Adventurers .... £173,914 ,, ,, deposited as a Reserve fund.,. 6,082 - 179,996 -— £1,422,634 “ In 1842 the engines, tools, and materials on the mines were worth £60,000.” Petition to Parliament by Joseph Thomas Treffry, Esq. (Abstract). The Caradon District. (Borlase, Antiquities of Cornwall , p. 173, PI. XII., Fig 1. Lysons, Cornwall, clxxxiv., 198, PI. VIII. Mac Cullocli, Geol. Trans., o.s., II. p. 169. C. S. Gilbert, Historical Stirvey of Cornwall, 1 . pp. 171—3, 247; n. p. 479. Rogers, Cornwall Geol. Trans, n. pp. 218—21. Bond, Historical Sketches of East and West Looe, pp. 203—16. Boase, Cornwall Geol. Trans., iv. pp. 208—10. De la Beche, Report on the Geology of Cornwall, &c., pp. 159,—85. Whitley, Geological Map of the Caradon Mining District. Allen, History of Liskeard, pp. 4, 27, 33, 204, 394—402,—18—32. Thomas, Remarks on the Geology of Cornwall and Devon, p. 15. Arundell, 457 Native Copper of Lake Superior . them all, no more than eight have hitherto given Pick and Gad, pp. 3, 54, 108. Giles, Cornwall Geol. Trans., vit. pp. 158,—98, 207. Salmon, Mining and Smelting Magazine, n. pp. 78— 83, 342; in. p. 364; v. p. 331. Ante, p. 120, Postea.) South Caradon is worked in the granite, on several lodes, which contain copper and its ores in abundance. ^y^afs^ 1836—65^ I t * ie sa ^ es h ave amounted to . £1,001,536 „ „ „ working expenses have been .. £675,088 „ ,, ,, Royalties (Dues) ,, .. 54,931 ,» „ „ Profits ,, .. 271,517 - £1,001,536 Teter Clymo, Esq., Manager“and Purser of the Mine, MSS. The Callington and Tavistock District. (Holinshed, Chronicle (Edit. 1837), II. p. 545. Polwhele, Historical Survey of Devonshire, i. p. 110 ; History of Devonshire, i. pp. 69 — 72; History of Cornwall, iv. pp. 133 — 5. Maton, Observations on the Western Counties, i. pp. 296 — 300. Berger, Geol. Trans., o.s., I. pp. 120 — 2, — 68, — 73. Thomson, Annals of Philosophy, n. p. 351. Lysons, Cornwall, pp. ccvi.—x.; Devon¬ shire, i. pp. cclxxx. —xc. Taylor, Geol. Trans., o.s., iv. pp. 147 — 52, PI. VIII. Sedgwick, Cambridge Phil Trans., I. p. 95. Carne, Corn¬ wall Geol. Trans., I. pp. 122—4; it. p. 104. Rees, Cyclopaedia, xxm. Article Mining; xxxii. Article Silver. C. S. Gilbert, Historical Survey of Cornwall , I. pp. 172 — 3, 219. Bond, Historical Sketches of East and West Looe, p. 110. Michell, Manual of Mineralogy, pp. 11 21,-8, 32,-3,-5, 79, 88,-9. Prideaux, Transactions of the Plymouth Institution, I. pp. 23,-5 — 30. Bray, Borders of the Tamar and Tavy, l. pp. 240, 310. Fox. Cornwall Geol. Trans., m. pp. 314,-21. Boase, Ibid, iv. pp. 220-3; Primary Geology , p. 186. DelaBeche, Researches in Theoretical Geology, pp. 219,385; Report on the Geology of Corn¬ wall, &c., pp. 61-2, 117,—19-22,—41-3,—56-7,—83-5, 296, 301-2, 401, — 98 ; Inaugural Discourse at the Government School of Mines, p. 10. Burr, Mining Review, tii. pp. 228,-32. John Phillips, Palaeozoic Fossils of Cornwall, Devon, and West Somerset, pp. 198, 201. Tooke, Mining Almanack for 1849, pp. 241-9. Sedgwick & Murchison, Geol. Trans., N.S., v. pp. 669-70, — 85-6. Henwood, Proceedings of the Geol. Soc., i. p. 405; Cornwall Geol. Trans., iv. p. 25; v. pp. 131 — 42, — 58, 400-1, — 75-6, Tables XCI. — VIII., PI. X. Rowe, Perambu¬ lation of Dartmoor, pp. 8, 232, — 91-8 (Moore, Appendix I.), 249-57. Leifchild, Encyclopaedia Britannica, xv. pp. 225-6. Orroerod, Quarterly Journal of the Geol. Soc., xv. pp. 16-23, 189-90. Arundell, Pick and Gad, i. pp. 3, 51, — 4, 105-6. Charles Thomas, Remarks on the Geology of Cornwall and Devon, pp. 7, 8, 16, 20. Pengelly, Reports of the British Association for 1861, Partll. pp. 127-9; Cornwall Geol. Tracis., vn. p. 419, Salmon, Mining and Smelting Magazine, v. p. 331. Report of Commissioners on Mines in Great Britain (Appendix B), pp. 313-21. Ante, pp. 109-10,—14-15,—44.) t( Gunnis Lake —worked in granite, immediately west of the Tamar—afforded a profit of £37,000.”— Sir William Williams, Bart., of Tregullow, MSS. The Devonshire Great Consolidated Copper-Mines —which have been worked in clay-slatc with the following results,—are still the richest copper-works in Europe. 458 W. J. Hen wood, on the dividends; and even of these seven only have Years. Copper- (pyrites) ore. Tons. Av. Receipts. a Expenditure. Profit. Proceeds. Sundries. > Totals. i — Salaries and Wages. Materials and sundries. Royalty C Dues J ■i Totals. £ £ £ £ £ £ £ £ 1855 401 4314 1024 5338 2605 7 — 2612 2726 6 13957 116069 2437 118506 30590 6154 8322 45066 73440 7 15118 93610 3252 96862 49110 15377 7189 71676 25186 8 15134 102933 3884 106817 57085 15661 7882 80628 26189 9 17410 101032 1473 102505 51810 14242 7628 73680 28825 1850 16204 104555 620 105175 49897 11683 7906 69486 35689 1 18155 117408 724 118132 52509 12344 8960 73813 44319 2 19894 118334 601 118935 51931 12605 9027 73563 45372 3 21931 147647 930 148577 68269 12992 10966 92227 56350 4 25598 153837 1586 155423 75115 15268 12117 102500 52923 5 24073 152489 CO 153364 64862 14693 11686 91241 62123 6 25119 140844 1054 141898 63023 12991 10770 86784 55114 7 30278 159432 1465 160897 61777 10663 11625 84065 76832 8 26431 138357 2074 140431 53387 22448 11377 87212 53219 9 24729 119497 11861 131358 47572 26546 9557 83675 47683 I860 23981 115285 3598 118883 50084 18730 9288 78102 40781 1 22925 108366 2376 110742 43349 11052 9117 63518 47224 2 21898 103330 1446 104776 41595 8923 8521 59039 45737 3 25854 118480 1666 120146 42396 10256 9594 62246 57900 4 28176 130175 2035 132210 51420 14219 10504 76143 56067 5 27075 134796 3888 138684 56310 • 12923 11220 80453 58231 Totals 444,341 2,480,790 48,869 2,529,659 1,064,696 279,777 193,256 1,537,729 991,930 Abstract of the Annual Accounts, from the commencement of operations to the end of 1865; printed for circulation amongst the Shareholders. On an average, therefore each ton of ore cost... £3 9 3. ,, „ ,, was sold for .... 5 11 8. For this important account the Author is obliged to Joseph Matthews, Esq., of Tavistock. Native Copper of Lake Superior . 459 yet yielded profit to the shareholders.* Wheal Friendship a is wrought in clay-slate; interlaid, at intervals, with thin beds of carbonaceous matter. The earliest and largest works were, in great measure, confined to one lode, but of late a second has been opened to advan¬ tage. Both are intersected by several cross-courses ; one of which has afforded great quantities of lead-ore, both here and in (Wheal Betsy) an adjoining mine. From the beginning of 1800 to the end of 1865 the returns were— Copper-ore . 145,803*1 tons (Av.) Lead- „ 1,170*4 Tin- .. 1620 v which realized.. £1,371,954 Arsenic-,, . 4,342*7 ,, J The machinery, materials, salaries, wages, &c., amounted to £970,263 „ Royalties (Dues) . ,, 111,883 „ Profit divided amongst the Adventurers ,, 289,808 -£1,371,954 Joseph Matthews, Esq., of Tavistock, Purser of the Mine. * “ Within the last twenty years, something over a hundred different companies have been organized for the purpose of mining on Lake Superior, and calls have been made on their stockholders to the extent of about thirteen million dollars (£2,708,333 Stg.); out of them all, only eight have ever made any dividends; not because of the price of copper, but for want of sufficient product. These eight companies have called for and returned the following amounts.— Pittsburg & ( Boston.. $ Minnesota .. Quincy .... Pewabic .... National .... Franklin .... Central .... Copper Falls. Assessments. Dividends. dollars £ dollars £ Mining Company, 110,000 ( 22,917 Stg.) 2,160,000 ( 460,000 Stg.) )* 366,000 ( 76,250 >> ) 1 ,760,000 ( 366,667 9> ) 200,000 ( 41,666 J • ) 700,000 ( 145,833 ) 75,000 ( 15,625 M ) 380,000 ( 79,167 )9 ) 110,000 ( 22,917 }) ) 280,000 ( 58,333 7) ) }) 170,000 ( 35,417 >> ) 220,000 ( 45,833 >> ) if 100,000 ( 20,833 )) ) 150,000 ( 31,250 >> ) }9 490,000 (102,083 >1 ) 60,000 ( 12,500 M ) T , S Assessments .... 1,621,000 (337,708 ,, ) Aotal * Dividends . .... 5,710,000 (1,189,583 „ ) Memorandum of the Smelters and Manufacturers of Copper ; submitted to the Representatives of the United States , by S. T. Snow, Esq., of the Revere Copper Company. a “ Statement op Rate of Profit per Cent, on Receipts, and Proportion of Doeb on Profit. 1 Number ' of years Amount of Receipts Amount of Cost. Rate of Dues Amount of Dues Profit Rate of Profit on Receipts Propor¬ tion of Dues on Profit Consolidated Mines.. 20 £ 2,099,491 £ 1,611,340 1-24 £ 87,453 £ 488,151 per cent. 23 25 per cent. 17-91 Wheal Friendship 7 148,354 112,251 1-12 12,213 36,103 24 33 88-83 Ditto 52 1 167,909 778,835 98,810 389,574 33*35 25-30 Lisburne Mines . • • • 6 173,257 110,894 1-10 16,110 62,863 36 28 25*62 East Crinnis 11 352,155 254,442 33,000 97,713 27-74 33-75 Carn Brea. 17 1,039,312 790,562 1-24 45,406 248,750 23-93 18*25 South Tolgus ... 3 38,217 22,817 1-15 2,548 15,400 40-29 16*54 “ Mean rate of profit on receipts .. . 26*6 per cent. a Ditto dues on profit .... . 22*0 ditio. ** PniLLirs & Darlington, Records of Mming and Metallurgy, p. 263. s s s 460 W. J. Henwood, on the ( d .) At the South Cliff mine (Table XIII.J, a deposit of (drift) boulders, shingle, gravel, and sand, of more than fifty feet in thickness, overlies the rocks ; # which—like those of the Cliff mine immediately north, —consist of alternating and somewhat ill-defined bands of granular and amygdaloidal trap; dipping—as they also dip—25o-30° towards the north, f But, inasmuch as the boundary between the mines is a vertical one, the upper parts of certain beds are in one mine, and the lower in another. The only lode —of which the adjoining portion is wrought in the Cliff mine—still bears 21° W. of N.— E. of S.; dips 75°-85° E.; £ and—varying from about twenty inches to three feet and a half—averages nearly two feet, in width. Calcareous-spar, quartz, and chlorite are abundant; and prehnite is a large—sometimes indeed it becomes the largest—ingredient; but Laumonite, zeolite, labra- In the Lisburne lead-mines (Cardiganshire) the produce, expenditure, and profits during 1857,—8,—9, were Amounts. Expenditure. Produce. £ 102,007 1 * * Working-costs. I Royalties {DuesJ. £ 67,801 | £ 9,816 Proportions. 06598 | 0-0962 Profit £ 24,890 0-2440 Moissenet, Annales des Mines , 6me Serie, ix. p. 122, * “ A shaft was sunk through from 8 to 12 feet of sand, and then through quicksand, until the stratum of hard-pan was struck lying directly on the rock, which, itself, was 52 feet from the surface.” Whitney, Metallic Wealth of the United States , p. 280. “ Les premiers travaux ont eu traverse les 18 metres (59-3 feet) d’alluvions qui couvrent la vallee.”— Rivot, Annales des Mines, 5me Serie, vn. p. 315. “ Many loose masses of native copper, some of which contained silver, and were of large size, were picked up.” Whitney, Metallic Wealth of the United States, p. 249. f Ante, p.422. J Ibid, 423. Native Copper of Lake Superior. 461 dorite, hornblende, and epidote are of merely local occurrence.* Large, rough, lenticular bodies of trap, here and there, divide the lode; f and—especially where the adjoining ( Country ) beds are granular,— smaller masses of kindred rocks, cemented by, and impregnated with, the other vein-stones, give it a brecciated character.J Both the included masses and the contiguous bands of trap, are traversed by short, narrow, veins of crystallized prehnite. Amongst them¬ selves the aggregated prisms generally preserve a tolerable parallelism; though small groups of divergent crystals occur at intervals; for the most part, however, they are disposed at considerable angles to the (walls) sides.§ Minute wedge-shaped bits of trap, and—in and near the longitudinal joints—granules of copper, ♦ Ante , pp. 423—4. f “ Vers le nord, le frton est divise en deux veines qui reunissent vers le milieu de la partie exploree, en pr^sentant. un renflement extremement riche.” Rivot, Annates des Mines , 5me Serie, vn. p. 315. J 41 Many of the veins have a more or less brecciated character; that is, they appear to be made up in a considerable degree of fragments of the adjoining rocks, cemented by the same veinstone as occurs in other veins.” Whitney, Metallic Wealth of the United States, p. 259. “ Dans le trapp compacte, grenu, amygdalo'ide, la gangue est formee de cal- caire, de quartz, de feldspath, de chlorite, et des fragments et debris des roches encaissantes.”— Rivot, Annates des Mines, 5me Serie, vn. p. 264. § 44 The quartz in the cross-courses is very peculiar in its crystalline structure, having a fibrous, striated, or radiated appearance, with the axes of the crystals, when not much radiated, nearly at right angles to the direction of the sides of the veins. * * * The cross-course spar usually shows divisions or joints at right angles, and consequently parallel to the sides of the veins, as represented b yfg. 18, Plate VI.” Fox, Report of the Royal Cornwall Polytechnic Society, iv. p. 89. De la Beche, Report on the Geology of Cornwall, Devon, and West Somerset , pp. 339 — 42. Phillips, Cabinet Cyclopaedia , Geology, ji. p. 132. Henwood, Cornwall Geol. Trans., v. p. 261. 462 W. J. Henwood, on the are—so to speak—entangled in the crystals of preh nite.* Fig 27. THE SOUTH CLIFF mine. A vein of prehnite between walls of trap. (Scale—one-half.) The small dark triangle, within the group of radiating crystals, represents a minute wedge of trap. Other spots denote grains of native-copper. No other part of the district has afforded, at similar depths, so many large masses of copper as the upper levels of this mine; f the heaviest occurring in those * “ The veinstone of this mine, near the surface, furnished beautiful specimens of prehnite with crystallized copper. An interesting specimen of the former mineral in radiated nodules in perfectly pure metallic copper (Fig. 23) is well worthy of notice, as throwing light on the origin of the metal in the veins.” Whitney, Metallic Wealth of the United States , p. 2S1. f In February, 1854, “ the whole amount of ground opened in driving was 715 feet; cross-cutting, 76 feet; sinking in rock 438 feet; stoping 126 fathoms. From these workings the extraordinary amount of 506,000 lbs. (2258 9 tons Av.) of stuff, yielding 67j per cent, of copper had been taken. “ The largest mass [until then] observed on Lake Superior, Tvas thrown down in this mine on 4th July, 1853 ; it was about 40 feet long, 20 high, and supposed to average 2 in thickness. Its weight was estimated at from 150 to 200 tons.” Ibid, p. 280. “ Les masses de cuivre sont nombreuses et de grandes dimensions. J’ai vu, en place dans la mine, un gros block deja degage sur environ 30 metres (16’4 fathoms) en hauteur et 7 a 9 metres (3‘8 to 4'9 fathoms) en direction ; son epais- seur, tres-variable, atteint 2 metres (6'5 feet) en plussiers points.” Eivot, Annales des Mines, 5me Serie, vu. p. 315. Native Copper of Lake Superior . 463 rich shoots of vein-stone which—situate on the boun¬ dary—belong to the South Cliff at and near the sur¬ face, but to the Cliff at greater depths. Ontonagon. (e.) The Toltec mine—some twelve or thirteen miles south-east of the harbour (mouth) of Ontonagon —is opened in alternating beds of granular and amyg- daloidal trap; composed mostly of hornblende and labradorite, mixed often with either epidote or chlorite, and sometimes with both. The principal lode —maintaining much the same strike as the adjoining trap-rocks, but more highly inclined than they,—bears slightly N. of E.—S. of W.; dips 55°—65° N.; and varies in width, from a few inches in some, to several feet in other, places. Its chief ingredients are quartz and calcareous-spar; but prehnite is not uncommon, and chlorite occurs at intervals. Angular blocks of trap, often imbedded in, and sometimes transfused with, the other constituents, give—when small—a brecciated character to the lode: but—when large— they, so to speak, divide it into branches. Native-copper is irregularly sprinkled through all—save the crystalline and trappean—parts of it; but rather in ( Stamp-work ) grains and (. Barrel- work) small bodies, than in heavy masses. # “ * The character of the lode varies very much in different parts of the mine. At [one spot] it dips 64°, and is about 3 inches wide; at [another], it has an inclination of 56°, and is 20 inches wide, and well filled with copper, a mass of a ton in weight has been found here. At other points it is from 2 to 3 feet wide, and very variable in richness. * % % The gangue of the vein is almost ex- 464 W. J. JIenwood, on the (/.) The Fire-Steel lode bears 10 °— 20 ° E. of N.— W. of S.; inclines 65°-80° W.; ranges from six inches to three feet in breadth; and consists, for the most part, of calcareous-spar, quartz, prehnite, epidote, and chlorite, irregularly charged with particles and small nuggets of copper. Its western side is bounded by a smooth (hanging-wall) face of fine-grained, crystalline trap; towards the (foot-wall) east, on the contrary, it passes gradually into an amygdaloidal rock, in which the joints are frequently lined with copper. (< 7 .) In the Indiana location trial has been made of three lodes , which traverse the fine-grained trap-rock from N.E. to S.W.; dip 40°-50° N.W.; and vary, from about three inches to as many feet, in breadth at differ¬ ent parts of their range. Trap, in various states of disintegration, is commonly the largest, and sometimes the only, constituent; though grains, small bodies, and clusively quartz, often well crystallized, and occasionally associated with fine specimens of prehnite.” Whitney, Metallic Wealth of the United States , p. 291. “ On a forme deux puits principaux et trois puits secondaires dans un filon tres-irregulier, dirig£ N. 60° E., et plongeant vers le nord sous un angle de 60° environ. * * * La puissance du filon est extremement variable, de 0 m06 a 2 metres (2’3 inches to 6'5 feet) et plus; des veines secondaires ont et6 con- state^s en plusieurs points. % * % Dans les etranglements, le filon est tres- quartzeux; dans les renflements, il est rempli par du quartz, de la chlorite, du calcaire spathique, da l’epidote verte, de la mati&re rouge et des fragments du trapp encaissant, formant des breches a grandes parties. On a constat^ des veinules de laumonite, mais je n’ai vu nulle part ce mineral en veines un peu puissantes. Les renflements presentent souvent des geodes en partie remplies par de l’argile rouge et tapisees de cristaux de quartz. % % % Dans les travaux actuels, on a trouve quelques petites masses de cuivre et ce metal dissemin6 en grains dans la gangue; la mati&re a bocarder parait tenir de 2| a 5 p. 100 de cuivre dans les parties riches.” Rivot, Annates des Mines , 5me Serie, vii. p. 321. Native Copper of Lake Superior. 465 short thin veins, of quartz, calcareous-spar, epidote, prehnite, Laumonite, and chlorite, either mixed or separate, occur at intervals* *. Granules, masses, and reticulated threads of copper are imbedded in all the earthy ingredients, but least frequently in the trap. Many ancient mine-works and tools * have been, from time to time, discovered in the neighbourhood. ( [h .) The What Cheer mine has been opened on two lodes , one bearing 35°-40° E. of N. —W. of S. ; & dipping 45 3 -56° N. W.; width un¬ known ; the other,, 5°-12° „ „ „ 50° W.; Both are, in great measure, composed of coarse¬ grained trap; but they also contain Laumonite, cal¬ careous-spar, epidote, quartz, prehnite, and chlorite, as well as jaspery and earthy red iron-ore. Particles and nuggets of metal, thinly invested with the green carbonate of copper, are sparingly scattered through the vein-stone. (i.) The Douglas Houghton or Henwood mines f (Table XV.; Fig. 28, 29.) had reached a depth of more than seventy fathoms in 1856, and they are but little deeper now (1866). “Masses of ice which had accumulated, at depths of 16-6 and 23*3 fathoms in the mine, during the winter of 1855—6, remained unmelted on the 11th of July following. * Ante, pp. 412—19. t “ The mining operations of this Company have been mostly confined to the north-western corner of Section 22, [Range 37, Township 51, where] low ridges of trap run a little to the east of north and present a steep face on the south eastern side, * % * The trap, which is a dark compact variety, occasionally amygdaloidal in its structure, is divided at intervals of 3 or 4 feet, though ir¬ regularly, by seams, which are filled principally with quartz and calcareous spar in very varying thicknesses. * * * When exposed on its mural face, it [ 466 W. J. Henwood, on the Fit/. 28. THE DOUGLASS HOUGHTON, 01’ HENWOOD, MINES, ONTONAGON—MICHIGAN. Longitudinal section. The rocks generally consist of hornblende and labradorite; but chlorite is also a frequent, and epidote is an occasional, ingredient.* * Isolated masses and short narrow veins of quartz,—mixed sometimes with calcareous matter, but perhaps as commonly with one appears to be divided by a number of seams which follow the general direction of the ridge; and, of course, have mostly a rather east and westerly direction. These are rarely continuous for any great length, yet they may in some instances be traced for a considerable distance. It is impossible, however, to decide on the identity of any two portions of one of these seams, unless the rock is ex¬ posed continuously along the whole course of them. [Their dip] is invariably with that of the rock itself—generally at an angle of about 45°. At many points of their course they*are accompanied by native copper, which sometimes occurs in very large masses.” Jackson, Report on the Geological and Mineralogical Survey of Lands in Michigan, in. p. 743. * “ The rock is a compact chlorite trap.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District, pp. 142—50. “ The rock adjacent [to the vein] contains a large amount of epidote.” Whitney, Metallic Wealth of the United States, p. 289. Native Copper of Lake Superior 467 or other of the surrounding substances,—occur at intervals. Within short distances of the lode particles and flakes of copper are scattered thinly and irregu¬ larly through them all. The structure is mostly coarse and granular; by degrees, however, it becomes fine¬ grained and crystalline in some, but amygdaloidal in other, places. The entire (Country) formation is disposed in somewhat ill-developed beds; which are intersected, at about right-angles, by well-marked joints. From the lode to the neighbouring (Country) rocks gradual transitions sometimes take place; but nearly parallel joints frequently form smooth divisions between them.* The principal lode f bears about N.E.—S.W.; and * Henwood, Cornwall Geol. Trans., v. p. 181. 1 “ The vein Hi Hi * is about three feet in width, running nearly north and south, conforming to the general direction of the ridge at this place, and dipping west 60°. They have driven a level about 25 feet along its course, and a con¬ siderable quantity of copper has been obtained. The vein-stone removed was rich in disseminated and string copper, and will yield from 8 to 12 per cent, of metal. Quartz, He Hi % forms the principal portion of the matrix, which is traversed by numerous seams of chlorite. The vein is well defined, and affords indications of proving highly valuable.”— Foster & Whitney, Report on the Geology of the Lake Superior Land District , I. p. 142. “ The vein, at the surface, appeared between two and three feet wide, with a quartzose veinstone, and was quite well filled with copper. At that point, it had two perfectly defined walls, separated from the rock by selvages of argillaceous matter, and a gangue distinct from the rock. In the workings of the mine, however, it has not so much regularity as would be desirable: in some places it is two feet in width, and well charged with copper; and in others it becomes entirely lost, and can with difficulty be traced. There is a break or fault inter¬ secting the vein vertically, Ht % Ht and displacing it to the amount of 14 feet. Two slides have also been found to traverse the rocks, and have shifted and deranged the vein along their course. % Ht Ht About 5 tons of barrel-work and mass copper were shipped in 1853, and 20 barrels of stamp and barrel-work, and four masses, amounting to 25 tons in all, were ready for shipment in Feb¬ ruary, 1864.”— Whitney, Metallic Wealth of the United States, p. 290. T T T 468 W. J. Henwood, on the is represented in various places by either slight traces of vein-stone or the mere, contact of (walls) faces of trap-rock, yet often attains a width of at least three feet; its average dimensions, however, do not exceed fourteen inches. The narrower parts—peculiar to the fine-grained and crystalline trap (Country) alone—are usually composed of Laumonite or chlorite, but now and then they contain copper. The wider portions— natural to the coarse, granular, and amygdaloidal rocks only — abound in quartz; largely, but unequally, mixed with calcareous-spar, as well as with smaller proportions of epidote, chlorite, hornblende, and, per¬ haps, a few other minerals. Isolated blocks of trap occur here and there. All these enclose copper,* in grains and rough shapeless nuggets of a few pounds each; but the siliceo-calcareous matrix only yields also masses of many hundred-weight. The richer portions are separated, by comparatively worthless vein-stones, into two distinct shoots; both which dip endlong towards the south-west. Undulating joints—not al¬ ways quite parallel to the (walls) sides in direction and dip—divide certain parts of the lode into (combs) slices or subordinate veins; which—at times enveloping lenticular bodies of trap—are commonly characterized by diversities either of composition or of structure. * “ A mass of copper recently taken from the back of the fifth level weighed 1000 to 1200 lbs. * * * A piece lately obtained above the fourth level weighted above 1500 lbs. * * * “ Over the back of the third level the stamp-work now being removed is of a higher per centage than the average of stamp-veins, say to 3 per cent." Lake Superior Miner (24th March, 1866) xi. p. 224. Native Copper of Lake Superior 469 Such joints are occasionally filled either with disin¬ tegrated vein-stuff and earthy red iron-ore, or with thin sheets of copper; of which the glossy faces are sometimes deeply grooved.* On their opposite sides, however, they are now and then fluted in different directions; and even within short distances, on the same sides, the striee are frequently curved, crooked, interrupted, and divergent. Fig. 29. douglass houghton, or henwood, mines. Grooved surface of vein-stone and copper. Natural size. Some of the quartz contains cavities lined with crystals; and much—like that of various gold-mines in Brazil j*—abounds in cracks, crevices, and flaws ; in such instances copper is scarce.;]: The following columns—-compiled from accounts kept at the mines—show the quantities of vein-stone * Henwood, Cornwall Geol. Trans., v. pp. 173,—81,—2, Tables XVIII., XCV .; Ante, pp. 13, 90, 433. f Ante, pp. 181—2. $ Henwood, Cornwall Geol, Trans., v, p. 206. J 470 W . J. Henwood, on the extracted from different parts of the mines, and the weights of (crude) copper separated from it, during 1854, 1855, and 1856.* * The National Mine has been worked in the same district (Whitney, Metallic Wealth of the United States , p. 297. Ante, p. 414), with the undermentioned results. n .2 . ts • Cr> fl Q ^ P 3<£~:2 « 'S •qjpuv ui jaaj aaiqj jnoqn paScjaAu opoj aqj, oo 0° I I Per sq. fm. of lode lbs. t^lC 05C005HC0TOONC0CD10N 05 OO >—1 CO CO r-H O HTHTf<(M05l0r'03TO05CC'il 00 (N ^ Cl TO COCO (NCIMTO(NCOTOCICO(NC'|H (N W CO CO TO (N 294 Totals tons (^v.) 005 mTO^MCUCHHOOCIHN TO CO H >C IQ tK OO (M TOOOOOOtH^OOTOOOOSTOiO i-h -^ © © © 05 P cb Pot-cboooobsibTHT^csixH cb bi P cb ib oo COCO COTOTOCOTOCOTO-^'^'^TjiTO TO ^lO TO 790-11 1*0 I'-g ^ § ® 'Zi ea g g 05-^ H 00 TO CO t|h CO 0 05 05 010 TO CO 00 TO i—ll>- NCOTOONTO TO TO 05 TO IM 1 W|3 H O 05 t— t^©cbiboiibcd-4icbcbibcd 'bicoibr^cb rH r—< rH rH r-H r-H r-H r-H r-H rH i-H r-H 230-26 0-292 Barrel- work tons (4».) H OO HG5TOO5NNt(INIOC0t|ih lOXOOOiOH 05 CO OTOO^MOSOCOHIOIMN NHTOTONH to to biooob-i^o^-Pcbibcbbo © © cd P oo © r-H r-H r-H r-H i—1 rH rH rH rH rH rH rH 205-79 0-260 1 2^ '5d'^ g s' 3 P g O t— NOlNlOHiONOOmiOlOTO H 05 TO 05 TO N 00 05(Ni|H(NrHrNNOTONH rf( TO O H (N OO 00 CO HibTOHrHN005TONOTO 100500050505 i-H i—1 rH rH »-H rH rH H H H rH OQ rH rH rH r-H 354-06 0-555 0-448 Jfa; Numbers CO TjieOTOOCOMMOSHTOTOCI 0 10 05MTOTO rH CM COCOCdCO-'^COCdCO-^COCd'tf 1 CO IM TO CO (N CO h a o rC a) CO J s ^ # m 6 h w tb i 05 05 rtl t-- 05 rH (N (N TO (M (N TO lo CO CO_ ib' I I .2 <15 » <55 05 OO(NHCOO5N>OOTONip0 cq bo5TH6b -4-> c3 Q CO co 00 > o O b »o> CO 00 c TO •g-s H'S P f£, cublc ” >• 588 The Masses —ranging from a few hundred-weight') to eight tons, and averaging (0*555ton) V—formed 0*448 of the entire 1,243 lbs. each .j produce; Barrel-work . ,, 0*260 ,, ; Stamp-work..... ... ,, 0-292 ,, From the 1st of November, 1863, to the 31st of October, 1864, 6,330 Avoir. (7,090 United States') tons of vein-stone yielded at the Stamps 140*57 tons Avoir —each ton thus affording 49*74 lbs.—(0-022206 the weight) of crude metal. Each stamp-head crushed on an average 2,964 lbs. of vein-stone in twenty-four (working) hours. (Ante, Tables VII. column 14, IX. Note m; p. 426, Note). The miners—whose numbers varied from 86 to 130 and averaged 114— broke—one with another—52-8 square fathoms ) . (A * h . of lode , which yielded \ tonS CAv '> a }ear eaCh ’ and earned— ,, —. £11:0:4 per month ,, . The labourers ranged from 48 to 50, and received ) f 9 • 13 • 1 on an average > ' ‘ ” Chynoweth (Report of the National Mining Company), Lake Superior Miner, xi. (7th October, 1865), pp. 32—4. 90*35 tons (Avoir) of crude metal from the National Mine, yielded—from the 1st of May to the 12th of July, 1866, 66-39 ,, „ (0*7348) its weight) of fine copper. Pontalba, Detroit Free Press, xxx. (28th July, 1866) p. 1. A comparison between the proportions of copper in the lodes near Lake Superior, and of tin-ore in those of Cornwall and Devon, can scarcely be uninteresting. 472 W. J. Henwood, on the In 1856 the entire produce—except from ynasses o O PS o •H c3 ; o 11 I pi 'S c3 5 j—4 rt o ^ (S >» n 208-29 „ of which the Stamp-work amounted to (0-2032 its weight) .... 42-33 „ .” Emerson, Lake Superior Miner, n. (17th January, 1857) p. 2, 482 W. J. Henwood, on the The lodes of Keweenaw are characterized by prehnite and various zeolitic minerals; those of Ontonagon by epidote; but, in both, quartz and calcareous-spar are prevalent vein-stones. The proportions and aggrega¬ tions of crude copper are shown in the following columns.— Districts and Mines. Keweenaw. The Cliff * * * § . Crude copper per square fathom of lode, lbs. 1,425 per cubic fathom of lode, lbs. f - Masses. Proportions. _A_ 0-139 Barrel- work, 0-081 Stamp- work. 0-780 -^ Totals. ,, South Cliff f. „ Copper Falls % .... Ontonagon. The National § . „ Mass [j. „ Douglass Houghton H 294 970 126 588 1,164 669 0-448 0-645 4 0-260 0-292 1 * 1 * From this it seems that the narrow and highly inclined veins of Keweenaw, which intersect the trap- range in about a meridional direction, and are dis¬ tinguished by the presence of prehnite and zeolite, contain larger proportions of copper than the larger * Whitney, Metallic Wealth of the United States, p. 227, Ante , pp. 434—5. f Whitney, Metallic Wealth of the United States, p. 280. Ante, pp. 460—3. if Whitney, Metallic Wealth of the United States , pp. 265—6. § Chynoweth, (Report of the National Mining Company), Lake Superior Miner , xi. (7th October, 1865) pp. 33—4. Ante, pp. 470—1, Note. || Chynoweth (Report of the Mass Mining Company), Lake Superior Miner , xi. (14th October, 1865) p. 42, Ante, p. 471. Native Copper of Lake Superior. 483 and flatter lodes of Ontonagon, which are nearly parallel to the adjoining beds of trap in direction, but are oblique to them in dip; strike east and west in some—but rather north-east and south-west in other, places; and abound in epidote everywhere. The ex¬ amples yet recorded, however, are too few to warrant general conclusions,* The writer was prevented from visiting several con¬ siderable mines, which he had been invited to examine, in the two principal copper districts. The neighbour¬ hood of Portage Lake has become important since his last mission to America. The thick beds of transported matter which overlie great part of this-still insufficiently explored-region, f * “ The Central mine, about 14 miles east of the Cliff , is opened upon a # & * lode consisting of a series of alternations of red laumonite strings, with large lenticular expansions containing copper. The original discovery of this lode was made in an old Indian working, [but] only a small amount of metal has been found immediately below this point in sinking; but further north, below the greenstone, under similar conditions to those observed in the Cliff mine , a very rich run of ground has been discovered. There is a good deal of ealespar in the vein, and the finer copper appears rather in sheets than in shots. At the 50- fathom level the largest mass that has yet been discovered on the lake was struck; it measured 50 feet in length, 30 in height, and about 4§ feet in greatest thick¬ ness and yielded somewhere over 500 tons of copper.”— Bauerman, Quarterly Journal of the Geological Society, xxn. [November, I860) p. 457. f “ The region of the great lakes may be considered as the headquarters of the North American drift. From the mouth of the St. Lawrence to the borders of Lake Superior there is hardly a spot where the drift deposites are lost sight of. There is, however, no place where these formations are more extensive than on the southern shore of Lake Superior; where, they not only constitute the only visible formation for nearly one hundred miles, but they also attain an astonishing thickness, % % % forming in some places cliffs not less than three hundred and x x x 484 W. J. Henwood, on the contain, at intervals, considerable quantities—and, in some places, large masses*—of copper. These seem to have been discovered by an earlier race of inhabi- sixty feet high, -k -h % The drift of Lake Superior may be divided into four deposites, which, in ascending order, exhibit the following characteristics:— 1st. “ A layer of coarse materials, # # % generally a mixture of loam and fragments of rock of different sizes,—sometimes worn, but more frequently an¬ gular. As a leading feature, it is almost exclusively composed of fragments of the rocks in sitH. % % # The whole mass is nowhere more than thirty feet thick.” “ 2nd. A layer of clay resting either on the coarse drift, or, where this is wanting, on the rock. # -Vr # It is difficult to determine its average thickness, from the fact that, in many places where it is highly developed, it sinks below the waters of the lake, and in other cases, where its base is visible, its top has been partly washed away. % * # It appears to be a mixture of loam and clay, and its colour is owing to the decomposition of the red-sandstone and trap from which it has been derived. Though the main mass is composed of very finely comminuted substances, and often of an almost impalpable powder, yet many pebbles are interspersed, and even boulders of considerable size, generally rounded and smoothed. Fragments of metallic ores and native copper occur occasionally in it—the latter sometimes weighing several hundred pounds. It was by these that the attention of the early travellers was first attracted to the copper mines of the region. % % % “ 3rd. A deposite of sand, gravel, and pebbles, irregularly stratified, % * % not only covers the clay deposite in most of the localities where the latter has been observed, but also extends over many places where this does not reach. % % % Layers of fine sand alternate in every possible way with layers of peb¬ bles,—sometimes by a gradual transition, at other times abruptly. The pebbles themselves are composed of all kinds of stone—some from the immediate neigh¬ bourhood, others from places more remote. They are generally rounded and smoothed. The same is the case with boulders imbedded in the mass, of which there are many from five to six feet through. * # % Its greatest thickness we found to be % X % about three hundred feet. * % % “ 4th. A considerable number of isolated boulders, scattered over the whole region, form the uppermost portion of the drift deposites. * * * As to their mineralogical composition, there is every variety of rocks to be found, and in many instances they may be traced to their origin at no very great distance.” Foster & Whitney,. Report on the Geology of the Lake Superior Land District , I. pp. 186—91. (Abridged.) * “ It is well known that, south of Lake Superior, transported masses of native copper arc occasionally met with, in the diluvial deposits which are so abundantly spread over the country. * * * The source of these transported masses has, heretofore, been somewhat obscure * # * but without doubt a very considerable of them had their origin from true veins. * * * The Native Copper of Lake Superior 485 tants than the Indians who now people the country; # —they attracted the attention of practical miners more than ninety years ago;f—and are still—as, perhaps, great transported mass of native copper on the Ontonagon river, which contains about four tons of metal, has all the characters of the other loose masses,” Douglass Houghton, Proceedings of the Association of American Geologists ; Silliman’s Journal , xli. p. 29. “ The copper-rock or boulder, which lies in the yard between the War and Navy Departments in Washington, has an extraordinary history. It was brought from the banks of the river Ontonagon, and has, it is said, been known over two hundred years. The Jesuits who first visited that part of the country, heard of it from the Indian priests, who however refused to conduct the missionaries to the spot where it lay, on account of a superstitious belief that when the white man had seen it the Indians would be destroyed. % * % “ During the visit of General Cass to this region in 1820, he sent a party of men to fetch it. They burnt a large pile of wood over it, with the intention of breaking or divesting it of rock, but its great weight prevented them from getting it away. “ In 1827 Mr. George Johnston visited it; but, as the river was high at the time, it was pretty much covered. He, however, succeeded in raising it on skids, and in cutting from it some fifty pounds of specimens. In the summer of 1841 or 1812 Mr. Paul and an educated half-breed named Nicholas Mincleer, built a cabin over it, with the intention to secure possession. After a time, when their claim seemed to be undisputed, it was removed, with great labour to the mouth of the Ontonagon river ; where it remained during the greater part of a summer, and was finally sold to Mr. Eldred. It was afterwards claimed by the Agent of the United States,.and was finally removed to the seat of Government. % * By order of Congress Mr. Eldred was paid the sum of five thousand six hundred and fifty five dollaas (£1,178 : 2 : 6 Stg.) for his services.” Lake Superior Miner , n. (26th September, 1857) p. 21. “ About [1864] two years since [a mass of copper], which weighed about 18 tons, was found loose on the drift covering the rock in the Mesnard location near Portage Lake.” Bauerman, Quarterly Journal of the Geological Society , xxii. (1864) p.452. * “ Claude Allouez [who visited Lake Superior in 1666] states that pieces of copper, weighing from ten to twenty pounds are frequently found by the savages.” Jackson, Report o?i the Geological and Mineralogical Survey of Lands in Michigan , hi. p. 377. Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p, 7. Ante, pp. 412—19. f “ The first actual mining operations within historical times were commenced near the Forks of the Ontonagon, in 1771, by Alexander Henry. Having 486 W. J. Henwood, on the they were by the aborigines—sought as guides to their parent lodes * * But less generally distributed,—or more correctly speaking—perhaps less frequently met with, than either the Shodes f and the Stream tin-ore J of Cornwall, or the (Cascalho) auriferous detritus § of Brazil, they have themselves—because of their market worked without success for a while at this point, searching in the clay bluffs which line that river for masses of native copper, operations were transferred in the next year to the north shore of the Lake; but, as might have been expected under the circumstances, they proved entirely abortive.” Whitney, Metallic Wealth of the United States , p. 247, “ On the side of a rivulet, ten leagues to the south of Lake Superior in North America, there is a single lump of native copper, about four tons weight, free from any mixture but a few small black Stones of an Iron nature, and some very fine grains of Crystal. % % % No vein of copper was discovered on the south side of the Lake, near this lump ; but some few very small ones on the north side, not worth the pursuit. This I had from two credible Miners of Redruth, who were sent over to make discoveries in consequence of this singular appear¬ ance.”— Pryce, Mineralogia Cornubiensis (published in 1778), p. 61. * Ante, p. 460. t “ Tin is found disseminated on the sides of hills in single stones, which we call Shodes, sometimes a furlong or more distant from their lodes, and sometimes these loose stones are found together in great numbers % % * which we call a Stream . —Borlase, Natural History of Cornwall, p. 161. “ In certain situations the Shodes are in greater quantities in valleys, than on the tops or sides of hills; but such are smaller, and more easily carried down by water, and formed into strata, which furnish our Stream-works. % % H: The heaviest stones are nearest to the lode, and the lighter are protruded % % even to five miles distance.”— Pryce, Mineralogia Cornubiensis , p. 125. JMaton, Observations on the Western Counties, i. pp. 159—74. Rashleigh, British Minerals, II. p. 25, PI. XXI.; Cornwall Geol. Trans, II. pp. 281—4. Hawkins, Ibid, I. p. 235, Smith, Geol. Trans., o.s., iv. pp'. 404—9. Colenso, Cornwall Geol. Trans,, iv. pp. 29—39. Came, Ibid, pp. 45—56. Henwood, Ibid, pp. 57—69 ; Y. pp. 90*, 110, 129. Winn, Reports of the Royal Institution of Cornwall, xxi. Ante, pp. 452—3. ^ Mawe, Travels in Brazil, p. 268. De Saint-Hilaire, Voyage dans le district des Diamans et stir le littoral du Bresil, i. pp. 127, 201. von Eschwege, Annales des Mines, Yin. p. 409; Pluto Brasiliensis, pp. 505—6. Southey, History of Brazil , m.p. 827. Claussen, Bulletins , de VAcademie, Royale de Bruxelles, vm. Ire Partie, p. 335. Ante, pp. 342—51 Native Copper of Lake Superior. 487 value—been in but a single—and that an unsuccessful —instance,* * the object of special pursuit. In 1819 and in 1823 Commissioners were appointed by the Government of the United States to examine the entire territory ; f and in 1841 a Report on its metallic products was presented to the Legislature of Michigan by Dr. Douglass Houghton.J It was not until the cession of several extensive tracts by certain tribes of Indians in 1843, however, that permission to search for minerals and to work mines was granted by competent authority; § but within three years nearly a thousand concessions were made.|| * Ante , p. 4S5, Note t. * f Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. p. 13. Whitney, Metallic Wealth of the United States , p. 247. Rivot, Annales des Mines, 5me S6rie, vn. pp. 179—81. + “ In 1841 Dr. Douglass Houghton, State Geologist, published an account of his observations, in the form of an Annual Report to the Legislature of Michigan, in which the first definite information with regard to the occurrence of native copper, in place, on Lake Superior, was given to the public; which did more than anything else towards awakening an interest in that region, and directing towards it the attention of explorers.” Whitney, Metallic Wealth of the United States, p. 248. Foster & Whitney, Report on the Geology of the Lake Superior Land District , I. p. 13. Rivot, Annales des Mines, 5me S£rie, vn. p. 180, § Foster & Whitney, Report on the Geology of the Lake Superior Land District , i. pp. 14—15. Whitney, Metallic Wealth of the United States, p. 248. || “ The whole number of permits granted under the authority of the Depart¬ ment of War amounted to about one thousand—nine hundred and sixty one were located. Sixty leases for tracts of three miles square, and three hundred and seventeen for tracts of one mile square were perfected, and mining com¬ panies organized under them.”— Foster & Whitney, Geological Report on the Lake Superior Land District, I. p. 15. “ In the summer of 1844 * % Hi the first mining operations were commenced on leases secured the year before * % * and discoveries of veins and deposits of copper in the rock were made. When these facts were reported in the eastern cities, of course with many exaggerations, a great excitement or copper fever was the result, and in 1845 the shores of Keweenaw Point were whitened with 488 W. J. Hen wood, on the The following columns—compiled from every avail¬ able source of information,—contain an approximate account of the produce, from the autumn of 1844 to the end of 1865. Years. Copper. __ j _ Years. Copper. r~ Fine. Tons Avoir. { Crude. Tons Avoir. Fine. Tons Avoir. 1845 . 12* * * * § ft 1852 . — 792 *ft 1846 . 26 * ft 1853 . — 1,297 * ft 1847 . 213 • f J 1854 . 2,054 t 1,563 § 1848 . 461 * -f j 1855 . 2,854 X 2,366 § 1849 . 672 * f t 1856 . 5,112 t 3,214 § 1850 . 572* ft 1857 . 5,142 t 3,884 § 1851 . 779 * f t 1858 . 5,264 t 3,580 || the tents of speculators and so-called geologists. Many hundred permits, or rights to select and locate on tracts of land for mining purposes, were issued by the Department, and three hundred and seventy seven leases were granted. Most of the tracts covered by these were taken at random, and without any explorations whatever ; indeed, a large portion of them were on rocks which do not contain any metalliferous veins at all, or in which the veins, when they do occur, are not found to be productive. In 1846 the excitement reached its climax; and the speculations were continued as long as it was possible to find purchasers. * * But every such mania must have an end, and in 1847 the bubble had burst, and the country was almost deserted. Only half a dozen companies, out of all that had been formed, were actually engaged in mining.” Whitney, Metallic Wealth of the United States , p. 249. Rivot, Annales des Mines , 5me Serie, vn. p. 181. Snow, Ante , p. 459, Note *. * Whitney, Metallic Wealth of the United States , p. 304. f Rivot, Annales des Mines, 5me Serie, vii. p, 327. t Report of a Joint Committee of the Senate and Representatives to the Legis¬ lature of Michigan , xix. (1861) p. 5. § John Simpkins, Esq., of New York, Metal Broker, MSS. || New York Daily Tribune , 19th January, 1859. Mining Journal, xxix. (12th February, 1859) p. 103. 489 Native Copper of Lake Superior . Years. Copper. A Years. Copper. .A. r- Crude. Tons Avoir. Fine. Tons Avoir. t — Crude. Tons Avoir. Fine. Tons Avoir. 1859 ... 6,469 * * * § f 4,543 § 1863 .. 7,632 ft 5,342 ** * * §§ 1860 ... 7,674 5,389 § 1864 .. 7,645 « §§ 5,352 **§§ 1861 .. 9,229 || 6,607 || 1865 .. 8,904 1 6,233 ** 1862 .. 8,064 ir 5,645 ** Thus, in less than twenty-two years after the com¬ mencement of systematic mining, this region has yielded some 58,542 (Avoir.) tons of fine copper. * Report of the Senate and Representatives of Michigan, xix, (1861) p. 5. t The Joint Committee ) of the Senate and Repre- f state the returns of „,,, TT ... tv.«q. sentatives of Michigan, & \ 1859 to haye been \ 7(245 Umted States ' or 6(469 Avotr *» Tons; the Detroit Daily Tribune) The Portage Lake Mining X Gazette, in., & the United f States Railroad <$* Mining > , Register, v. (2nd Feb. 1861) i No. 37, . ) t The United States Rail- ) states the returns) way and Mining Register, > in 1860 to have [ 8,578 No. 37.. ) b 6,041 99 5,394 99 8,578 99 7.659 99 8,592 99 7,671 99 8,614 99 7,691 99 9,200 99 8,214 99 v. (2nd Feb. 1861) No. 37.. ) been The Detroit Daily Tribune. „ Portage Lake Mining Gazette ) a , HI. (1861).ji ” . ,, Joint Committee of the Senate ) and Representatives of >..9,200 Michigan, xix.) § “ 8,543*4 tons of rough are equal to 6,000 tons of ingot copper.” United States Railway and Mining Register, v. (.2nd Feb., 1861) No. 37. || Dupee, Beck, and Sayles. Portage Lake Mining Gazette, in. IT The Mining Journal, \ states the returns \ xxxxiii. (llth April, 1862) J in 1862 to have > 9,015 United States, or 8,049 Avoir., Tons. p. 258, ..) been. ) The Mining Gazette . ,, .9,019 „ 8,053 „ Ontonagon Miner . „ . 9,062 „ 8,091 ** Crude metal, estimated to yield 70 per cent, of fine copper. ff Ontonagon Miner. Lake Superior Mining Journal. Mining Journal, xxxv. (8th April, 1865). §§ Bauerman, Quarterly Journal of the Geological Society , xxii. (Nov. 1866), p.456. 1111 Mining Journal, xxxvi. (Feb. 3rd, 1866), p. 66. For most of these particulars the Author is indebted to his Friend, Ebenezer North Willcox, Esq., of White Woods, near Detroit. » 9 9 490 W. J. Hen wood, on the Metalliferous On the Metalliferous Deposits of Gloucester, in New Brunswick. Notwithstanding great part of Gloucester is still covered with virgin forests, many natural sections of the granite, slate, sandstone, conglomerate, and shale are exposed on the coast, and in the banks of several rivers, which converge towards Bathurst the County- town.* * (I.) The granite rises from beneath other rocks near the Bay de Chaleur, and extends thence in a south¬ westerly direction to the confines of the Province.^ r \ * “ The town of Bathurst is situated on either side of a harbour, or bay, some six or eight miles in depth, and four or five wide, which is formed by the mouths of three rivers—the Tatagouche, the Middle, and the Nepisiguit—which fall into it.”— Johnston, Notes on North America, n. (1845) p. 250. f Lyell, Travels in the United States, n. (1845) p. 250, PI, II. “The granite, gneiss, and mica-slate form a broad riband extending across the Province, between two bands of clay-slate rocks.” Johnston, Report on the Agricultural capabilities of Neio Brunswick (Second Edition, Fredericton, 1850), p. 8. “ The primary rocks of granite, gneiss, and mica-slate, form a broad belt extending directly across the Province, near its centre, in a north-easterly direction. # % % It enters the Province from the United States above Wood- stock, embracing Mars Hill near the Des Chutes river, and the range of hills known as the Tobique mountains, all which, however, are less than 2,000 feet in height, except one which rises to the height of 2,170 feet. At the western end, this belt of hilly country, is supposed to be 40 miles wide; but it narrows gradually in its north-easterly course, and the hills decrease in height, until they finally disappear before reaching the Bay of Chaleur near Bathurst.” Perley, Hand Book of Information for Emigrants (London, 1857), p. 31. “ A low range of granite stretches from the Atlantic coast of Maine to the Bay of Chaleurs.”— Hind, Preliminary Report on the Geology of New Bruns¬ wick (Fredericton, 1865), p. 41. “ The great central belt [of granite], entering the Province from the State of Maine, passes through the counties of York, Northumberland, and Gloucester, and extends to within a short distance of the Bay of Chaleur, at Bathurst. ” Bailey, Observations on the Geology of Southern New Brunswick (Fredericton, 1865), p. 84. Rocks of Gloucester in New Brunswick . 491 It occurs on both the Little and the Middle (Ne- pisiguit) rivers; and has been traced along the banks and in the bed of the (Big-river) Nepisiguit, at intervals, for nearly twelve miles towards the south. Greyish-white or pale-pink felspar, semi-translucent or milk-white quartz, and dark mica, are the common ingredients. The structure is mostly granular; though now and then it becomes porphyritic, as large crystals of flesh-coloured felspar abound. Sometimes, however, these preserve, among themselves, a certain parallelism; and the rock then—opening in somewhat ill-defined beds—assumes rather the character of gneiss.* At Glendinning’s island, near the last rapid in the Rough-waters of the Nepisiguit, a broad felspathic dyke of porphyritic structure t—bearing 20°—30° W. of N.-E. of S.—intersects the ordinary granite. And at the falls of the Pabineau as well as at the Middle Nepisiguit the prevailing rock is traversed by narrow veins of quartzose granite of which the greater * “ The granite is first seen near the coast on Middle river, about a mile and a half west of the Nepisiguit, and an eighth of a mile from the Harbour. It appears on the Nepisiguit at the Rough Waters [which for] more than two miles flow over it. Ht * % Two and a half miles above the Pabineau falls granite also occurs in low domes on the north side of the Nepisiguit. “ At Rough Waters it consists of white felspar, black mica, and translucent quartz.”— Hind, Preliminary Report on the Geology of New Brunswick , pp, 42—3. “ The curious and beautiful channels of the Pabineau Falls are formed of nearly flat and water-worn masses of pinkish granite, which probably forms a great anticlinal axis.”— Bailey, Observations on the Geology of Southern New Bruns¬ wick, p. 11 (abridged). f “ At the foot of the Rough Waters there is a felspar dyke containing red crystals of the same mineral.” Hind, Preliminary Report on the Geology of New Brunswick , p. 44. + Henwood, Proceedings of the Geological Society of London , in. (1841), p. 454. Y Y Y 492 W. J. Henwood, on the Metalliferous number bear 25°-40° S. of E.—N. of W., but some range 20°-25° W. of N.—-E. of S. # Earthy brown iron-ore (gossan )—largely mixed with quartz in one of these—is the only metallic mineral yet found in the granite, f The granite of different localities, is divided by joints, in the undermentioned directions. t - Little Localities. _A_ Directions.* Middle Nepisiguit Nepisiguit Molloy’s .... I „ Second spot „ Third spot Falls of the ) ( Pabineau J i if Second spot | Rough-waters ) r i ; 25° N. of W. i — S. of E. 20° W. of N. 1 1 . 1 [ 30°N. of E. — E. of S. ! f 1 [ — S. of W. . | ' 20° N. of E. j 1. — S. of W. . j [ 25° E. of N. [ _ W. of S. 20° W. of N. 25° N. of W. 25° E. of N. — E. of S. — S. of E. — W. of S. 20° W. of N. 25° N. of W. — E. of S. — S. of E. ’20° W. of N. 25° N. of W. 40° N. of E. . — E. of S. — S. of E. — S. of W. (II.) The slate series is of varied character. (a.) A fine-grained though an irregular admixture of felspar and hornblende, thinly sprinkled with small crystals of felspar, forms sometimes a crystalline, but more frequently a thick lamellar, slate, of green, grey, or brownish hue; which dips towards the west, and * “ In 1840 the Magnetic declination observed at Dalhousie (Heron) island in the river Restigouche was 20° 15' West.” Bayfield, Phil, Trans , cxxxix. (1849) p. 211. Sabine, Ibid , PI. XIV. t “ Beyond their application for building purposes % * * the rocks of this series are without economical value.” Bailey, Observations on the Geology of Southern New Brunswick, p. 86. Rocks of Gloucester in New Brunswick . 493 either overlies, alternates with, # or is penetrated by highly felspathic, and occasionally hornblendic, granite,f in various parts of the Middle river. The slate contains much quartz ; which occurs now and then in isolated masses, but more commonly in veins. Most of these are only a few feet, but some are several fathoms, in length ; and though usually less than an inch, one here and there is three or four inches, in width. Notwithstanding their somewhat variable direction, they often affect two distinct series; one bearing 20°—25° E. of N.—W. of S., the other about E and W, The first coincides with one system of joints in the granite below ; J but both are oblique to the cleavage. Where they interfere—a few unite; —some are simply intersected by others;—and, oc¬ casionally one is (heaved) displaced by another; but the displacements—even of similar parallel veins by the same intersecting vein—are frequently in opposite directions.^ And sometimes the vein which intersects * “ The granite consists of a series of very narrow belts (at least ten in number on the Miramichi) with schists and metalliferous slates between them.” Hind, Preliminary Report on the Geology of New Brunswick, xm. De Luc, Geological Travels, in. p. 293. William Phillips, Geol. Trans. , o.s., ii. pp. 152—5. Sedgwick, Cambridge Phil. Trans, i. p. 122. Richard Thomas, Survey of the District between Chasewater and Camborne , pp. 10, 34, 44. Came, Cornwall Geol. Trans, ii. p. 74. Hawkins, Ibid, p. 378. von Oeynhausen & von Dechen, Phil. Mag. § Annals, v. pp. 241—2. Boase, Cornwall Geol. Trans., iv. p. 303. Henwood, Phil. Mag. # Annals, x. p. 360 ; Cormoall Geol. Trans., v. pp. 50,-8. 61, 71, 96, 148, Tables VII., XXI.,XLIII., LIII., LVI1I., PI. VI. fig. 5. f “ At the Middle river the granite is overlaid by thick-bedded greenish slate ; which is traversed, near the junction by numerous veins of granite.” Henwood, Proceedings of the Geological Society of London, in. p. 454, ^ Ante, p. 492. § Thomas, Survey of the District between Chasewater and Camborne, p. 22. Ante, p. 183, Note. 494 W. J. Henwood, on the Metalliferous in one spot, is itself intersected in another. All these, however, are severed by beds and narrow veins of granite. In the same neighbourhood a broad band of felspar porphyry * * * § interlies the slate, conforms to its cleavage, and shades into it gradually on either side. Neither metal nor ore, of any kind, has yet been found in the vicinity. ( h .) At Long Meadow, on the Nepisiguit, many irregular concretions, and short, crooked, veins of quartz, are enveloped in a thin body of much-contorted, green, chloritic slate,f which separates the granite J from the sandstone. From the Middle Landing to the Red Brook the slate still abounds in chlorite; but disintegrated felspar is not uncommon, and scales of red iron-ore often face both the planes of cleavage and the joints. (c.) At Daly’s—an eastern settlement—on the Tat- tagouche§—the slate is homogenous, deep-blue,—and of silky lustre. Its planes of cleavage—which dip towards the north-west—are interlaid by short, thin, conformable beds and small concretions of quartz, slightly sprinkled with iron-pyrites, and minute quan¬ tities of yellow copper-ore. * Henwood, Proceedings of the Royal Geological Society of Cornwall , 9th Oct., 1840. f “ Near the Long Meadow a greenish slate-rock is in contact with the granite.” Henwood, Proceedings of the Geological Society of London , in. p. 454. t Ante , p. 491. § In the Maps of the Society for the Diffusion of Useful Knowledge (130—1) this river is called the Jittingouche. Rocks of Gloucester in New Brunswick. 495 (i d .) About eight miles north-west of Bathurst the Tattagouche rushes through a wooded ravine, scarcely a stone-throw in width, but, perhaps, one hundred feet in depth ; where—from the different hardness, and the unequal wear, of various parts of its bed,—it forms a singularly beautiful cascade. The rocks immediately below the fall, and their con¬ tinuation in either bank, consist mostly of greenish chlorite irregularly banded with brown felspar; open¬ ing—obliquely to such bedding—in a somewhat im¬ perfect lamination, which dips towards the south. The precipice is flinty-slate of chocolate hue; divided, by short curved joints, into small lenticular masses, of compact structure at the surface,* but slightly schistose underground. The succeeding rocks are generally thick lamellar, but occasionally they are fissile; their colours are of every variety between chocolate-brown and light-pink, yet sometimes they are either shaded with green, or mottled with black and white. Isolated cubic crystals, as well of vitreous copper-ore as of iron-pyrites, occur at considerable intervals; and from this part of the series, — but from no other, — a few specimens of Crino'idea have been obtained, j* The grey and black * “ Close to an interesting fall of the Tatagouche, where it partly cuts its way through, and partly falls over, the edges of hardened slate-rocks, a manganese mine [was formerly wrought].”— Johnston, Notes on North America, n. p. 10, f “ In a reddish-brown slate near the Tatagouche falls some portions of an Encrinite were found.” Henwood, Proceedings of the Geological Society of London, in. p. 454. “ At the falls of the Tattagouche % * * the beds of slates are highly colored, 496 W. J. Henwood, on the Metalliferous oxides of manganese are often separately aggregated,— but are occasionally mixed with brown iron-ore,—in short, narrow, lenticular masses, small shapeless lumps, and thin strings of quartz flecked with slaty matter; which—generally conforming to the planes of cleav¬ age, though now and then throwing off branches on either side,—are, at intervals, enclosed in the slate, for a width of several fathoms.* * (e.) The rocks next in succession have much the same composition and structure, but are of bluish- green hue, and silky lustre. They alternate, at wide intervals, with bands of greenstone; which, unlike the flinty-slate at the falls,—are compact underground, but schistose at the surface. Both the clay-slate and the greenstone are interlaid by conformable beds of rather different character; which are usually several in some parts red, in others deep brown or black, and strongly resemble those near the Falls of the Nepisiguit. They cross the stream with a strike E. 10° S., having a dip of about 50° towards the South.” Bailey, Report on the Mines and Minerals of New Brunsicick, p. 12. Hind, Preliminary Report on the Geology of New Brunswick, p. 149. * “ At the Tattagouche falls a reddish-brown slate contains many small ver¬ micular and nodular masses of the oxide of manganese.” Henwood, Proceedings of the Geological Society of London, in. p. 454. “ Grey oxide of manganese, highly crystallized and of fine quality, has been worked to some extent on the Tattagouche river, near Bathurst, and thence shipped to England.”— Perley, Hand Book of New Brunswick, p. 36. “ The manganese is found in veins of various sizes, imbedded in quartz, and running without much regularity through the slates, which are everywhere stained with it. The manganese, which is the black oxide, is highly crystallized and affords very handsome and brilliant specimens, the crystals being sometimes as much as half an inch long, and grouped in fibrous, radiating, and stellate forms. The lode-stone of the manganese is both heavy-spar and quartz, the lode-walls being slates.” Bailey, Report on the Mines and Minerals of New Brunswick , p. 13. Rocks of Gloucester in New Brunswick . 497 fathoms—though at times of but a few feet—in length ; and commonly from twelve to eighteen inches—yet now and then of three or four feet—in width. Their central parts consist mostly of quartz; but towards their extremities they shade gradually into the slate, and are no longer identified. Several of these, and a few of the joints, contain quantities of iron-pyrites; sometimes slightly mixed and thinly sprinkled with yellow copper-ore.* (f.) Near Clarke’s camp, an upper part of the same river, and at Armstrong’s brook, one of its tributaries, homogenous, blue, clay-slates,j' which alternate with narrow bands of greenstone, are interlaid by conform¬ able beds of quartz mixed, more or less, with slaty clay, calcareous-spar, and galena, as well as with iron and copper pyrites. Several such beds have been opened at both places, but in vain. (g.) Within a short distance of Bathurst the Little (river) Nepisiguit falls, in a picturesque cascade, over a broad bed of greenstone; disposed in layers alter¬ nately of compact and of schistose structure; fine¬ grained in some, but coarse and porphyritic in other, places. The cleavage of the rather fissile, homogenous, * “ The copper lodes do not approach those of manganese, although both are imbedded in metamorphic slates. There is, however, a marked difference of color between them ; the manganese rocks being reddish and approaching black, while those bearing copper are of a bluish tint. The two are conformable— i.e. their planes of stratification are parallel—the manganese being superior. Both are inclined at a very high angle. % % Ht The lodes containing the copper ore are numerous, there being no fewer than seven within sixty feet. * % * They are composed of quartz, rocks called fiugan and gozzan by the miners, with mundic or iron pyrites, and the ore, copper pyrites/’— Bailey, Report, p. 13. f Henwood, Proceedings of the Geological Society of London , in. p. 454. 498 W. J. Henwood, on the Metalliferous glossy, bluish-grey, slate it interlies is, on both sides, parallel to that of the schistose greenstone. Both above and below the fall, the clay-slate, for a width of several fathoms on either side of the broad band, is likewise interlaid by conformable beds, composed chiefly of quartz, yet here and there mixed with slaty matter, scaly red iron-ore, and iron pyrites.* After short ranges, however, all such beds merge in the ( Country) slate. ( h .) From ten to twelve miles up the Middle (river) Nepisiguit the quartzose clay-slate which prevails is interlaid by lenticular bodies of quartz ; but—though enclosing isolated masses of slate—they afford no trace of ore. (i.) At the Narrows of the (Big river) Nepisiguit homogenous, glossy, deep-blue clay-slate alternates with broad bands of quartz, here and there friable, but generally of granular structure. These are, in many places, heavily charged with iron-pyrites; which has yielded to atmospheric influence and deeply tinged its matrix.t * “ Among the specimens shown me by Mr. Baldwin, formerly Sheriff of Gloucester County, was one of auriferous quartz, which he had found upon Grant’s Brook, a branch of the Little Nepisiguit several years ago. Its surface exhibited numerous branching veins of gold, and promissed to yield, by crushing, considerably more. He had since hunted for more in the same locality, but without success.” Bailey, Report on the Mines and Minerals of New Brunswick, p. 14. t Red slates, similar to those which are found near Woodstock, are seen a little above Nine Mile Brook. The river runs on the strike of the rock here, and the purple-red slates which occur five miles higher up the stream, are repetitions of the red slates, more deeply colored with manganese than iron. Indeed, it may be said that for a distance of six miles the river appears to flow on or close to the belt of red slates, with their iron and manganese ores.” Hind, Preliminary Report on the Geology of Neiv Brunswick, p. 148. Rocks of Gloucester in New Brunswick . 499 (j) In the crumpled and contorted chloritic slate,* which prevails near the Middle Landing, disintegrated felspar is occasionally a large ingredient. The joints are often faced with minute crystals of quartz, and filled with earthy red iron-ore. (■ k .) Between the Middle Landing and the Portage- brook spheroidal concretions of argillaceous matter abound in certain beds which alternate with the ordi¬ nary thick-lamellar, bluish-grey, clay-slate. At and near the water’s edge, it contains a few thin layers of quartz sprinkled with iron-pyrites; but, after very short courses, they dwindle and disappear. (/.) The Chain of Rocks consists of fine-grained greenstone-slate. ( m .) The Grand fall of the Nepisiguit has worn a deep pit in the, slightly quartz-veined, dark-blue clay- slate at its foot.f (w.) At the edge of the fall globular and reniform masses of quartz, crystals of felspar, and lamellar hornblende form thick beds; interlaid by a band of similar ingredients, but of compact structure, in one spot; and by lenticular bodies of quartz, said to con¬ tain copper-pyrites, in other places.J * Ante, p. 494. f “ Below the Falls, and close to the first Salmon Pool there is a belt of glistening talcose-micaceous schist, * * * of a brilliant and lustrous golden color.”— Hind, Preliminary Report on the Geology of New Brunswick , p. 148. “ All the rocks in this vicinity are highly ferruginous, the slates being some¬ times micaceous, and at others containing cubical crystals of the sulphuret of iron.”—B ailey, Report on the Mines and Minerals of New Brunswick, p. 10. In this pool two Indian boatmen, who accompanied the writer, speared, by torch-light, twenty-three salmon in an hour. ^ “ The slates just below the Falls are porphyritic, but a cursory examination failed to detect in them any traces of copper. % % % zzz 500 W. J. Henwood, on the Metalliferous The following columns show the strike and dip of the cleavage, as* * well as the directions of certain joints, in the slate-rocks already mentioned. Localities. _A_ ^ r Cleavage. _A_ Joints. _A_ Tattagouehe .... Little Nepisiguit Middle Nepisiguit Nepisiguit Direction. Dip. Direction. Daly’s ...... r 25° E. of N. N.W. 60°-70° [— W. of S. V Falls*. '20°N.of E. S. 60°—70° [— S. of W. Above Falls.. E.—W. .. S. 45°—50° (N.E.-S.W. S.E. 65° .. S.E.—N.W. Clarke’s camp | 25° E. of N. ) 25° S. of E. (. —W. of S. | S.E. 70° .. ; —N. of W. Armstrong’s brook .... 1 25° E. of N. S.E. 70° .. ; 25° S. of E. 1 —W. of S. { —N. of W. r 25°E. of N. S.W. 70° .. S E.—N.W. [ —W. of S. f 25° S. of E. [ — N. of W. Narrows .... ( 25° W.of N. S.W. [ — E. of S. Long Meadow f — Contorted. ( 40° W. of N. Middle Landingf i — E. of S. “ At the Grand Falls a highly siliceous rock, of slaty character, was seen to contain specks of sulphuret of copper.” Hind, Preliminary Report on the Geology of New Brunswick, p. 147— 8. “ Contorted slates form the wild scenery of the Nepisiguit Falls.” Bailey, Report on the Mines and Minerals of Neto Brunswick , p. 10. “ On the lower Nepisiguit, near the Grand Falls, I collected the sand and gravel which had been lodged in crevices on the side of a deep declivity down which a small stream flows in spring and autumn. I washed about one gallon of the sand and found several small grains, two filaments, and some very fine gold.”— Hind, Preliminary Report on the Geology of New Brunswick, p. 224. * « These beds of slate * * * cross the stream with a strike E. 10°S.,having a dip of about 50° towards the south.”— Bailey, Report , p. 13. f “ Pursuing our way from the Falls, we pass over sandstones and slates dip¬ ping westward.”— Ibid, p. 10. Rocks of Gloucester in New Brunswick 501 Localities. _A_ Nepisiguit ^ r Cleavage. _A_ Direction. Dip. A furlong below j | 40° W. of N. S.W. 6O°-70 Grand Fall* * * § .. | [ — E. of S. 1 ' 40° W.of N. S.W. 70° Below G. Fall* [ — E. of S. . Grand Fall .. j [40° W.of N. 1 — E. of S. S.W. 70° (III.) The succeeding rocks are conglomerates, sand¬ stones, and shales. (a.) About two furlongs below Blackstock’s mill on the Tattagouche, the conglomerate—which abounds in rounded masses of slate and quartz,—rests, in almost horizontal beds, on a fissile, greenish, but somewhat variegated, slate; of which the cleavage dips about 70° towards the S.W.f (5.) The thin stratum of contorted slate, which rests on granite at the Long Meadow,J is overlaid by nearly horizontal beds of conglomerate,^ and these * “ Below the Falls, the talco-micaceous schist [has] an easterly dip.” Hind, Preliminary Report on the Geology of Neio Brunswick , p. 148. f “ The clay-slate % % % which forms both banks of the Tattagouche * * % is overlaid near Blackstock’s mill by the % # # conglomerate of the coal- measures.”— Henwood, Proceedings of the Geological Society , in. p. 454. “ The country over which we passed [between Dalhousie and Bathurst] con¬ sisted of the highly-inclined upper Silurian beds, with occasional limestones occurring among them, # # % , Over these rocks, in many places were spread, in patches more or less extensive, horizontal old red-sandstone beds.” Johnston, Notes on North America, n. p. 2. t Ante, p. 494. § “ Near the Long Meadow a very much contorted greenish slate-rock, which rests on the granite is overlaid by a coarse quartzose conglomerate, with appa¬ rently a ferruginous basis.” Henwood, Proceedings of the Geological Society, in. p. 454. “ Two miles below the Second Landing [nearly horizontal strata belonging to the Bonaventure formation] cover up rocks belonging to the Quebec Group; and on the north side of the river they form cliffs 20 feet high, consisting of brick- red shales and sandstones, resting upon a coarse conglomerate.” Hind, Preliminary Report on the Geology of New Brunswick, pp. 57,-9. 502 W. J. Henwood, on the Metalliferous are succeeded by layers of siliceous sandstone deeply tinged with iron. (c.) From the Red Brook upward a similar con¬ glomerate rests almost horizontally on the granite.* * * § Notwithstanding a dyke of porphyry and veins of granite traverse the granitic mass within a short dis¬ tance, f and similar veins penetrate the slate at the Tattagouche,J neither one nor other enters either the conglomerate, sandstone, or shale. (i d .) A few fathoms above the high-road from Bathurst to Miramichi the left bank of the Nepisiguit presents the following section — * “ From within a mile of Bathurst to the Pabineau falls the granite is sur¬ mounted by conglomerates and sandstones of the coal-measures; the beds of which are almost exactly parallel to the surface of the rock beneath.” Henwood, Proceedings of the Geological Society , hi. p. 454. 11 The Bough Waters, more than two miles long, flow over granite, but on either side the Bonaventure [conglomerate and sandstone] formation may be recognized reposing horizontally upon it, and filling all depressions.” Hind, Preliminary Report on the Geology of New Brunswick , p. 59. Messrs. Hind and Bailey describe various parts, and tributaries, of the Ne¬ pisiguit by names different from those by which they were known, to the inhabi¬ tants of Bathurst, and to the Indian-boatmen who accompanied the writer on that river, in 1840. f Ante, p. 491. j Ante, p. 494. § “ This formation was seen at Bathurst, by Sir William Edmond Logan, and described by him in the Geology of Canada . % % The following section of the strata occurs at and near the abandoned mine, on the Nepisiguit;— feet 1. Chocolate-red micaceo-arenaceous shale, with casts of shrinkage cracks . 30* 2. White quartzose conglomerate, the thickest part of which is two feet, diminishing in one direction to two inches, in the space of 15 yards. The bottom is very white, and contains quartz pebbles, some which are an inch in diameter ... 1* 3. Whitish-red argillo-arenaceous shale, forming a passage to the next bed below ... 0.5 Carried forward31-5 Hocks of Gloucester in Neiv Brunswick . 503 North—north-east. feet. 1. Drift, containing pebbles of granite, slate, & quartz .. 2 2. Reddish-brown siliceo-mica- ceous sandstone. 30 3. Quartzose conglomerate. 1 a ce m3 £ W 4. Blue argillaceous shale, con- 2 , taining lignite and the ^ remains of plants, irapreg- .5-| nated in some places with S & copper-ores .0—3 5. Siliceous sandstone .. thickness o c unseen. ^ South—south-west. feet. 1. Drift , containing pebbles of granite, slate, & quartz .. 2 2. Reddish-brown siliceo-mica- ceous sandstone. 30 3. Blue argillaceous shale, con¬ taining lignite and the remains of plants, impreg¬ nated in some places with copper-ores...0—3 4. Quartzose conglomerate. 1 5. Siliceous sandstone .. thickness unseen. (e.) About two furlongs further up the river, the materials—in a lower part of the bank—are somewhat differently disposed ;— feet. 1. Drift, containing pebbles of granite, slate, and quartz .. 2* 2. Coarse quartzose conglomerate ... 1*5 3. Reddish-brown siliceo-micaceous sandstone . .. 1*5 4. Quartzose conglomerate, interlaid by a few r thin beds of sandstone.. 3—5‘ 5. Brownish-red sandstone, interlaid by thin beds of greenish hue ... 1*5 6. Blue argillaceous shale, containing lignite and the remains of plants; slightly penetrated in some places with copper-ores. . 1—4* 7. Quartzose conglomerate . thickness unseen. feet. Brought forward. 31‘5 4. Whitish-red argillo-arenaceous shale in parallel layers; this bed thins out about 30 yards up the stream. It is charged with the remains of broken plants, some of which are replaced by the vitreous sulphuret of copper, coated with a thin covering of green carbonate. Some are in part replaced by the copper ore, and partly converted into coal. Small nodules of the sulphuret of copper also occur, chiefly in the lower part, and traces of nickel are said to have been found in them. The greatest thickness of the bed is four feet; its average . 2* 5. White quartzose conglomerate, similar to that of the summit. This does not thin out in the distance examined, about 50 yards . 4* 6. Red Sandstone conglomerate with white quartz pebbles; of which some would weigh three ounces [each] .... 6* 7. Red Shale. .. 6* 8. Red Sandstone conglomerate, with quartz pebbles, some weighing a pound and a half [each] . 10* 59-5 Hind , rreliminary Report on the Geology of New Brunswick , pp. 57,—9. 504 W. J. Hen wood, on the Metalliferous In those portions of the shale, which are numbered 3 on the S.—S.W. side of the joint and 4 on the N.— N.E. side of it in the first section, two (levels) drifts— one about twenty, the other nearly thirty, fathoms long—have been opened; in the part marked 6 in the second section another—though a much smaller— opening has been made ; and, at some distance from all three, a shaft was sunk to the same horizon. The shale presents many slight undulations; but, on the whole, it dips 6°—10° towards the E. Its thick¬ ness seldom exceeds four feet, and is generally between two and three ; but in at least one instance it gradually dwindles and at length dies out; a second thin bed, of nearly similar character, however, appears a few feet above the last traces of the first. The rock, when newly broken, is often thick-lamellar; but a slight exposure developes its fissile character; and, under the influences of heat and moisture, it is rapidly degraded. The principal bed of shale is rich in the remains of plants; but they are often broken and decomposed. Amongst them, however, the following have been iden¬ tified by William Lonsdale, Esq., F.G.S., Sir Charles Lyell, Bart., D.C.L., F.R.S., and Robert Etheridge, Esq., F.R S.E., F.G.S.: viz.— Pinnularia capillacea* * Pecopteris Cistii* P. ovata ,* P. pteroides , # j~ P. muricata , # j' P. Sillimani (?),f Neuropteris Loshii * Sphenopieris elegans* S.acutifolia* S. Honingkausi* * Named by Robert Etheridge, Esq., F.R.S.E., F.G.S., Palaeontologist to the Geological Survey of Great Britain. * ,, Sir Charles Lyell, Bt., D.C.L., F.R.S., Travels in North America , First Series, n. pp. 198, 201,—2. Rocks of Gloucester in New Brunswick. 505 Calamites Suckovii* * * § C . clubius , J Lepidodenclron * L . AsterophyHites longifolia* A. equi- setiformis* A. cuneataf A. tuberculata,* Other genera and species have since been found, in the same neighbourhood, by Sir William Edmond Logan, LL.D., F.R.S.§ (f.) At Parrot’s-brook, near the Capes, an erect fossil tree,|| of about fourteen inches in diameter and some twenty-two feet in length, was (1840) exposed in the face of the cliff. It was rooted in a thick bed of argil¬ laceous shale, which rested on a thin seam of coal; but at different heights its trunk was enveloped in alternate * Named by Robert Etheridge, Esq., F.R.S.E., F.G.S., Palseontologist to the Geological Survey of Great Britain. f ,, Sir Charles Lyell, Bt., D C.L., F.R.S., Travels in North America First Series, n. pp. 198, 201,— 2. „ William Lonsdale, Esq., F.G.S., late Assistant Secretary and Curator of the Geological Society. § The undermentioned plants have been discovered, near the Bay de Clialeur, by Sir William Edmond Logan, LL.D., F.R.S., F.G.S., Director of* the Geolo¬ gical Survey of Canada: viz .—Calamites Cistii, Aster ophy llites grandis, Anna- laria galoides, Sphenophyllum saxifrag folium, S. emarginatum, Nceggerathia dispar, Neuropteris rarinervis, N. Loshii, Odontopteris Schlotheimii, Sphenopteris Canadensis, S. obtusiloba (?), Alethopteris nervosa, A. Serlii, A. grandis, Beiner- tia Goepperti, Lepidodendron verticillatum, Cordaites borassifolia. Dawson, Quarterly Journal of the Geological Society , xxii. pp. 151—164. J| Jackson & Alger, Mineralogy &c. of Nova Scotia, (1832) pp. 69, 70. Gesner, Geology &c. of Nova Scotia (lass'), p. 158. Lindley, Benny Cyclopcedia, vn. p. 294. Binney, Reports of the British Association for 1842, Part n. p. 50. Lyell, Travels in North America, First Series, n. p. 195; Proceedings of the Geological Society, iv. p. 176. Dawes, Ibid, p. 292. Binney, Lond„ Edin., <$, Dublin Phil. Mag., xxiv. p. 167. Binney & Harkness, Ibid, xxvn. p. 241. Dawson, Quarterly Journal of the Geological Society, n, p. 136. Lyell, Ibid, p. 171. Binney, Ibid, p. 390. Brown, Ibid , p. 393. Lyell, Ibid, in. p.262. Brown, Ibid, iv. p. 46 ; v. p. 354. Binney, Ibid , vi. p.20. Brown, Ibid , p. 128. Dawson, Ibid, vn. p. 124. Jackson, Report on the Albert Coal Mine , p, 8. Dawson, Quarterly Journal of the Geological Society, x. p. 1. Logan, Ibid, p. 39. Dawson, Acadian Geology, pp. 129,-59,—61—85. Phillips, Quarterly Journal of the Geological Society, xiv. pp. 90, — 8. Dawson, Ibid, xv. pp. 67, 635 ; xvi. p. 269 ; xvn. p. 522 ; xviii. p. 5 ; xxn. pp. 104, 108—25,—28,—32,—34,— 50—1,—9. 506 W. J. Henwood, on the Metalliferous layers of carbonaceous shale rich in the remains of plants, and of almost barren ferruginous sandstone; fragments of both which strewed the beach. One well-marked system of persistent joints bears about 25° E. of N.—W. of S.; but innumerable others, in different directions, though of shorter range, give some of the surfaces a tessellated aspect.* Lignite is largely mixed w r ith the other remains of plants in the shale wrought—as already mentioned— at the Victoria mine near Bathurst; but pieces of more than a few inches in length are rare.f Whether * Jukes, Quarterly Journal of the Geological Society, in. p. 248. f “ Wherever traces of woody fibre occur, in the soft bluish shale, copper- appears to have been deposited. The largest quantity of ore occurs, however, in small concretions, the inner parts of which are usually composed of vitreous copper and the outer of copper-pyrites, or the reverse; whilst a few nodules consist of vitreous copper, and still fewer entirely of pyrites. Thin scales of the green and blue carbonates of copper invest the other ores. Although this impregnation has been found over a considerable tract, the ores obtained have not repaid the expense. “ Some portions of the shale give out, on being broken, a most powerful odour of garlic.”— Henwood, Proceedings of the Geological Society, in. pp. 454—5. “ The Gloucester Mining Company expended much labour and money in searching for copper at the mouth of the Great Nepisiguit.” Gesner, New Brunswick, p. 198. “ Grey sulphuret of copper has been found in small quantities % * % on the left bank of the river Nepisiguit, near Bathurst, and a Company was formed some years since to work the deposit; but the irregular distribution of the mineral rendered their operations uncertain, and the mine has been abandoned.” Perley, Hand Book of Neio Brunswick, p. 37. “ The Bonaventure strata contain fossil plants, which about a mile above Bathurst, on the Nepisiguit, have been replaced in part by sulphuret of copper, which again has become converted into the carbonate at the surface, % * % The replacement of vegetable matter by the ores of copper is by no means un¬ common ; it has been described by Dr. Dawson as occurring % * * in some of the lower beds on the Joggins coast in Nova Scotia, and Sir William Logan states that a combination of ccal and grey sulphuret of copper occupies the forms of vegetable remains in a regular eighteen-inch bed which seems to crop out all around a considerable mountain in the Spanish Pyrenees.”— Hind, Preliminary Report on the Geology of Nero Brunsioick, pp. 57—8 (Abridged). Rocks of Gloucester in New Brunswick. 507 it has been derived from a single, or from more than ** In light bluish shales, sandstones, and both fine, coarse, and crumbling conglomerates, * % % about a quarter of a mile from the Nepisiguit bridge, copper was found and removed to the extent of 20 or 30 tons. It consisted of grey copper and the green carbonate intimately associated with the mineral called lignite, a peculiar variety of coal. * * Hi The distribution of the ore, being found irregular, and the whole deposit uncertain in its character, the enterprize was abandoned. At the time of my visit very little of the pure copper¬ bearing lignite could be found. The few specimens obtained were removed from a fine bluish clay, interstratified with the sandstones and conglomerates. These latter, like the lignite, are charged with copper, and a general greenish appear¬ ance, due to the weathering of that metal, is seen along the bank for a consider¬ able distance.” Bailey, Report on the Mines and Minerals of New Brunswick , p, II. “ On the banks of the Carriboo river, two miles from where it empties itself into the Gulf of St. Lawrence, occurs a bed of copper ore, included between the strata of sandstone passing into coarse conglomerate. It is associated with lignites of enormous size, which generally lie over the copper ore. * * * The lignites are black, and some of them resemble common charcoal. Some are fibrous, and exhibit evident traces of the organized structure of plants. # * * The lignite forms thin layers over masses of the copper ore, which sometimes presents substitutions or casts of culmiferous plants. The lignite sometimes contains minute flattened crystals of red oxide of copper. Green and blue carbonates of copper invest some of the lignites, fill interstices in the sandstone, and encrust the masses of vitreous copper ore. This valuable substance occurs in beds of from two to four inches thick, which, covered with lignites, alternate with each other, the lowest bed being thickest and most compact. The most compact variety is 5'7, but the granular varieties seldom exceed 4-8 or 5* in specific gravity. This ore yielded by our analysis Copper . 79*5 Sulphur.. 18*0 Iron . 2 5 100 * ” Jackson & Alger, Geology and Mineralogy of Nova Scotia, pp. 73—6. (Abridged.) “ About eight miles north of Pictou, on the banks of the Carriboo River there is a bed of copper ore, enveloped and intermixed with lignites. Large trees, in some instances retaining the vegetable fibre of the wood, and impressions of the leaves, bark, and all those figures so common on the surface of the living plant, are sometimes wholly transformed into lignite, [whilst] in other cases the ancient herbage of a productive climate [has become] half stone, half coal. # # * In breaking open masses of these once majestic trees, now transformed into jet and bituminous lignite, the green carbonate of copper often appears, forming an efflorescence in their crevices, The blue carbonate, and the red oxide of copper, also appear occasionally, both in the lignite and the sandstone. The copper ore A A A A 508 W. J. Henwood, on the Metalliferous one, kind of wood has not been ascertained. In many is deposited in narrow veins, from one to four inches in thickness, and alter¬ nating with the lignite and sandstone. * * * Compact masses [are] of the specific gravity of 5-5.”— Gesnek, Remarks on the Geology and Mineralogy of Nova Scotia , pp. 139—40. (Abridged.) Near “ Seaman’s Brook in Mill Cove # # # we see in the low cliff and in the shore reefs beds of reddish and greyish sandstone, alternating with reddish shales. * * * In a few places we find amongst these beds layers of gypsum and of sandy limestone. In several of the grey beds there are fragments of trunks and branches of trees, converted into coal; [and] associated with these remains, we find in four of the beds small quantities of the grey sulphuret and green carbonate of copper.”— Dawson, Acadian Geology, p. 124. “ The principal fossils found near Pictou are Calamites, Lepidodendron, Endogenites , coniferous wood, ferns, Artisia, and carbonized fragments of wood impregnated with iron pyrites and with sulphuret and carbonate of copper.” Ibid, p. 252. “ In the coast-section westward of the entrance to Pictou harbour * * * much red sandstone appears ; and a bed of limestone from two to three feet thick, and a small bed of coal have been discovered. Some grey sandstones also appear: in one of which there are numerous fragments of carbonized wood, containing sulphuret and carbonate of copper,”— Ibid, p. 253. “ In all these places the principal ore is the grey sulphuret of the metal, with films and coatings of the green carbonate. * * * The only reason which prevents them from being worked, is the conviction that the deposits are too limited to be of economical importance.”— Ibid, p. 267. “ At the Zavods of Yugofski and Motovilika * * % cupriferous grits, sand¬ stones, and shale have been largely excavated in several places. These beds, which are pierced by shafts from 35 to 130 feet deep, consist of thick flaglike grits of grey and dingy colour, rarely ferruginous, sometimes of greenish hue, and occasionally slightly calcareous, with courses of red and grey ribboned marl and shale. The ores of copper, chiefly the green carbonate, are disseminated at intervals through all the beds, but in this district the grits are the most cuprifer¬ ous. On the whole, the lower beds are more grey and dark coloured, and the upper strata redder. Plants of at least twenty species diversify the series in this locality, and in some of the lower they are so numerous as to have given rise to thin seams of coal, occasionally from two to three feet thick. Concretions, often cupriferous, six to eight inches long, occur here and there, and they have been generally formed around carbonized stems of plants. Both here, and in other places, the copper ores are very frequently found to be arranged in the interstices, and around the fossilized stems and branches of plants; exhibiting passages from the common oxide of copper to the grey sulphuret or copper pyrites, and occasionally to the finer varieties of bright green acicular malachite, mixed with crystals of the blue ore. All these beds are nearly horizontal. The cupriferous beds contain 2J per cent, of ore only, but from the wide dissemination of the ore through vast masses, its extraction is profitable. * * * In the dis¬ tricts near Perm, 108 cubic feet of wood are consumed to extract a poud, or about Rocks of Gloucester in New Brunswick . 509 specimens all trace of organic character has been ob¬ literated ; but, wherever it remains, the fibrous struc¬ ture strictly conforms to the nearly horizontal bedding of the contiguous shale. Such masses are not un- frequently penetrated by irregular veins of vitreous copper; but they seldom exceed two inches in length, or one-eighth of an inch in width, and are generally much less. The minute branches , which, at intervals, diverge from their sides, are often crooked and un- symmetrical in the massive lignite : but—though often of different lengths and thicknesses,—they strictly interlie the fibres, wherever the original structure pre¬ vails ; and thus sections of chosen specimens often display segments—and at times entire rings—alter¬ nately of vitreous copper and of lignite. The richest portions of the formation, however, consist of rough globular and reniform concretions, sometimes as small as pease, frequently as large as pigeons’ eggs, though generally about the bigness of marbles: of these — one, here and there, is wholly of copper-pyrites, — a few are entirely of vitreous copper, — and many present a nucleus of copper- pyrites enveloped in vitreous ore; but for the most [36*1] lbs. English of copper ore ; and the cutting and converting the wood into charcoal cost 2f roubles (about 2s. If d. Stg.). The poud of copper sells at from 32 to 34 roubles (from £1. 7s. 1<7. to £1. 8s. 9£f?.),and costs the Government 23 (18s. 9 d.), whilst individuals whose establishments are not so expensive, produce it at 18 roubles (15s, 3 d.). iThe Imperial Zavods near Perm afford 16,000 ponds (257‘9 tons Avoir.) per annum, and as the net gain per poud is 10 roubles 60 copecks (nearly nine shillings), the Government profit is [169,600] roubles, or about [£7,180] sterling per annum, after defraying all costs, pay of officers in¬ cluded.”— Murchison, deVerneuil, & von Keyserling, Russia in Europe and the Ural Mountains , i. pp. 144, 477. 510 W. J. Henwood, on the part they consist of vitreous copper within and pyrites without. Both they and the cupriferous lignite are thinly encrusted with fibrous malachite, and slightly speckled with the blue carbonate of copper; both occur at irregular intervals, and both are most numer¬ ous where the shale inclines most towards the south. From this part of the series, however, neither vein nor isolated granule of copper-ore has yet been ob¬ tained. At the Capes kidney-shaped nodules of red iron-ore —made up of concentric layers alternately earthy and of diverging fibrous structure—abound in upper shales. From 1838 to 1841 costly proceedings were carried on, by an English Company, in several parts of the district; but the returns were small, and any prospect of success, which might have lent countenance to the earlier operations, had vanished before the works were abandoned. Copper-bearing Granite of Jamaica. 51! Note on the copper-bearing Granite of Saint Thomas in the Vale—Jamaica. The rocks which extend in a south-easterly and north-westerly direction from Saint David to Saint Mary, * consist mostly of felspar and hornblende; in divers places, however, they are unequally mixed, not only with one another but with many other in¬ gredients ; moreover their structure is as varied as their composition. (a.) Near the eastern boundary of Saint Thomas in the Vale—within this district—the Sue river, a tributary of the Agua Alta, rises in a low round- topped hill of hornblendic granite; containing por- phyritic crystals of pale-pink felspar and small ill- defined masses of dark-green hornblende, imbedded in a basis of whitish, granular felspar and quartz, thinly flecked with pearl-white mica, f Of this rock a portion some four or five fathoms wide—identical with the granite on either side in composition, and, like it, divided into slices by joints bearing 3°—8° S. of E.— N. of W.J—contains many egg-shaped and globular concretions of ore; of which some consist almost en¬ tirely of copper-pyrites,—others contain earthy black *De la Beche, Geol, Trans., n.s., ii. PI. XVIII. + “ The Agua Alta presents a good section of [the] rocks between Stony Hill and Scot’s Hall (Maroon Town); * * * the whole of which may be con¬ sidered as one great mass with sometimes one ingredient predominating and sometimes another ; * % * porphyries, greenstones, and syenites seem to pass into each other.”— Ibid, p. 165. J “ In 1847 the Magnetic declination at Jamaica was 3° 50' East. Barnett, Phil. Trans., cxxxix. (1849) p. 216. Sabine, Ibid, Pl. XIV . 512 W. J. IIenwood, on the Copper-hearing copper also,—in a few earthy brown iron-ore abounds, —and occasionally iron-glance prevails; moreover the green carbonate of copper invests most of them, and faces many of the joints. They range from the size of pease to that of walnuts, and, whilst mostly scat¬ tered in irregular groups, one here and there occurs singly. The nearest concretions are now and then connected by almost microscopic threads of pyrites; * but, excepting these, neither vein, bed, joint, crevice, nor leader of any kind occurs in the neighbourhood. The proportion of ore was nowhere sufficient to repay the cost of extraction. (Z>.) Broad bands of similar hornblendic granite extend from the metalliferous body to considerable distances in the adjoining fine-grained greenstone; where particles and grains of copper-pyrites and scales of malachite may also be traced on corresponding— nearly E. & W.—lines of symmetrical structure. Joints of a second series range about N. & S.; but they are slightly developed in the metalliferous granite. * “ At Wheal Vyvyan * * % an enormous granitic lode bearing 20°—30° S. of W., and dipping 35°—50° N., is from 5 to 10 fathoms wide, and in some places even more. In composition it differs little from the neighbouring country, except that, perhaps, it may contain less mica: both are of porphyritic structure with buff and flesh-coloured crystals of felspar. The whole substance of the lode is thinly interspersed with tin-ore, copper-pyrites, and also with spots of iron-pyrites, and here and there a little vitreous copper. These metalliferous minerals are, however, chiefly disposed in small veins and strings, which most commonly coincide with the lode and the joints of the rock both in bearing and dip. The crevices, which occur at intervals, are often lined with crystals of tin- ore.”— Henwood, Cornwall Geol, Trans., v. p. 73. (Abridged). Sandstone of Huidobro in Spain. 513 On the Copper-bearing Sandstone of Huidobro in Spain. The mines of Huidobro, some thirty miles N.N.E. of Burgos and about three W. of Pesadas, are opened in wooded hills, which enclose an amphitheatre on all sides, except on the north where the drainage escapes through a rocky gorge. The rocks bear 30°—35° S. of E.—N. of W., # dip 25°—30° S.W., and maintain—in their earthy ingre¬ dients—a tolerable uniformity throughout the district. (a.) The lowest visible member of this series is a fine-grained, siliceous, sandstone; usually buff or greyish, but occasionally of brownish, hue. Rough spheroidal concretions of the blue carbonate of copper are scattered through it at unequal intervals; but they are too small and too few to stimulate pursuit. (5.) The succeeding bed is a thin one of mottled tenaceous clay, here and there slightly impregnated with granular quartz, but entirely destitute of ore. (c.) A great thickness of sandstone overlies the clay, but only a portion of it is metalliferous. Quartz— often tinged, more or less, with brown iron-ore, is always its chief ingredient; but nests of the sulphate of barytes occur in a few, and lignite—as well of earthy as of fibrous structure—abounds in many of the lower layers. Narrow, unconnected, floors of quartzose con¬ glomerate overlie all the richer deposits. Even within * In 1840 the Magnetic declination near Bilbao was about 22° West. Quetelet, Phil. Trans. , cxxxix. (.1849) p. 208. Sabine, Ibid, PI. XI F> 514 W. J. Hen wood, on the Copper-hearing * short distances the metalliferous portions vary much in thickness; for in the Borriga * mine they range from fifteen to nearly forty, and average about twenty-five, feet; but at the San Juan,* directly east, they scarcely exceed ten; and in the Expectativa * immediately west, they are even thinner. In this part of the series horizontal partings or joints prevail. Small isolated bodies of iron and copper pyrites have been discovered at Expectativa , little pockets of earthy black copper-ore at Borriga , and thin lines of vitreous copper at San Juan; whilst the blue carbonate of copper abounds throughout the district, and malachite is yet more plentiful.')' At Borriga , however, the richest of the carbonates have been ob¬ tained near several shallow horizontal joints, between, and, for short distances, on either side of which the sandstone is more ferruginous than elsewhere. In the hill-side, about forty fathoms below San Juan , an ancient drift extends near seventy fathoms towards the south ; but—notwithstanding copper is precipitable * Some fifteen years ago a Spanish mine-owner brought with him to this country about a ton of rich copper-ore; representing it as the produce of— San Juan and Expectativa —mines which he was anxious to sell. So large and rich a sample, naturally attracted attention; and a Surveyor, of some experi¬ ence, was forthwith dispatched to examine the properties. He saw, at once, that the specimens, shewn him before his departure, differed materially from the ore afforded by the mines offered for sale, but remarked that they closely resembled that of—the Borriga —an adjoining mine, wrought under English superintendence. And ascertained that,—of the carbonates of copper exhibited in London,—the Spaniard had culled some five hundred-weight from the yield of his own mines, and had bought the other fifteen hundred of his neighbours. f “ Copper-ore has been found, and works have been opened in the New Red Sandstone near Pradoe. * * Ht Specimens of the rock, indicate the dissemi¬ nation of the green carbonates, in minute quantities through the mass of sand¬ stone.”— Muechison, Silurian System , pp, 39, 297. Sandstone of Eardistan, Shropshire . 515 from the water accumulated in it—all traces of ore cease at some distance from the end. As the metalliferous mass was so thick and so slightly At Eardiston, near West Felton in Shropshire, portions of extensive ancient mine-works in the New Red Sandstone, have been, of late years, wrought for nearly eighty fathoms in length and sixteen in depth. The rocks consist, in great measure of granular quartz, and—when it is un¬ mixed—they are generally white; for the most part, however, ferruginous clay is also a constituent, and then yellow, brick-red, and brownish hues prevail. Minute proportions of calcareous matter occur at intervals. The metalliferous bed bears 12°—18° E. of N.—W. of S.,« dips 30°—40° W'., and—averaging some four feet—ranges from a few inches to about five feet, in width. Although bounded in many places by (smooth walls) joints, it just as often shades gradually into the adjoining rock; generally affecting, however, three subordinate layers, slices , or combs in most, but four in a few, parts of its course. It consists, in great measure, of granular quartz, but—near the surface especially—earthy brown iron-ore is also a large ingredient. Malachite—though less abundant—occurs in considerable quantities, and grains of a grey copper-ore appear at intervals. The following columns give some idea of their disposition in different parts of the mine. Layers. East. Lower.. (1) Sandstone, heavily charged with malachite. Middle.. (2) Sandstone, spotted with malachite. Upper .. (3) Idem. Middle of the Mine. (1) Sandstone, spotted with malachite. (2) Ferruginous sandstone, thinly sprinkled with mala¬ chite. (3) Sandstone, densely charged with malachite. West. (1) Feruginous sandstone, sprinkled with malachite and grey copper-ore. (2) Sandstone, enclosing grains of malachite. (3) Ferruginous sandstone. (4) Ferruginous sandstone, largely mixed with mala¬ chite and spotted with grey copper-ore. Although small (vughs) cavities in the ferruginous sandstone are often lined with mamillary malachite, the middle is ever the poorest part of the formation. A thin, highly-inclined, layer of tough blue clay unites with the metalliferous bed at about sixteen fathoms from the surface; when every trace of ore at once disappears. A narrow cross-vein of ferruginous clay traverses, but does not (heave) dis¬ place, the copper-bearing band; for some distance south of the intersection, however, the ore is less plentiful than elsewhere. “ The ores obtained during 1841—3 yielded from 0-08 to 0*25 their weight of metal, and realized altogether about £2,500.” Frederick Bankart, Esq. (of Langley Lodge, Herts), MSS. “ The existence of copper ores in rocks of the same age is well known. * * % [They] occur in the south-eastern face^of the Peckforton Hills # * % in strings a In 1838 the Magnetic declination was about 25° 30' West.—Ross, Phil , Trans., cxxxix., 1849, p. 208. Sabine, Ibid, PI. xiv. B B B B \ 516 W. J. Henwood, on the Mines of inclined, it was more convenient to quarry, than to mine, it. The rock was, therefore, scarped for nearly twenty fathoms in height; notwithstanding the upper, and by far the larger, part was unproductive. ( d .) The surrounding hills are capped with greyish- white limestone. (e .) At Borriga and Expectativa notable quantities of petroleum have, from time to time, been obtained.* and veins associated with dislocations more or less transverse to the main direc¬ tion of the red sandstone, the only exception * * * being in Stanner Hill, where certain poor mineral veins appear to range from south-west to north-east, or parallel to the ridge. “ The rocks of Hawkstone [are] analogous to those of Alderley Edge, in con¬ taining traces of copper ore and ferruginous oxide of cobalt, together with con¬ cretions and veins of sulphate of barytes.” Murchison, Silurian System , pp. 39, 298. “ The metalliferous formation, wrought in the New Red Sandstone at Alderley Edge, bears about S.E. and N.W., and is for the most part nearly vertical, though in the bottom of the mine it slopes slightly towards the S.W. * * * “The vein-stone-as in all other metalliferous deposits-bears a close resemblance to the adjoining rock. The ores—chiefly the green, but now and then the blue, carbonate of copper—are thinly diffused, and accompanied occasionally by earthy cobalt ore. * * * The proportion of copper obtained from the ore scarcely exceeds 2§ per cent.”— Higgs, Cornwall Geol. Trans., vn. p. 325. (Abridged.) * James Mason, Esq. (Baron de Pomeron, Knight Commander of the Order of Christ), MSS. Chalanches D’Allemont, in France . 517 On the Mines of CHALANCHES D’ALLEMONT, in France. The small well-cultivated plain below Bourg d’Oisans in the department of the Isere is traversed from S.E. to N.W. by the Romanche; and from E. to W. by the Olle, one of its tributaries. Immediately N. of their union, the mountains of Chalanches—portions of the Alpine chain—rise some (2,050 mitres) 6,720 feet above the table-land, or (2,750 mitres ) 9,020 feet above the sea. # The middle and upper parts of the range consist of granitic gneiss, in which felspar and hornblende are always large ingredients; sometimes, however, quartz and calcareous spar abound, epidote occurs at intervals, and talc, chlorite, or mica is not uncommon.'!' The rock, though now and then fine-grained—is mostly * De Thury, Journal des Mines , xx. p. 42. Gueymard, Sur la Mineralogie, la Geologie, et la Metallurgie du departement de VIsere p. 217. f “ La montagne des Chalanches * * * est formee de gneiss et de horn¬ blende. * * * Les bancs de ces rochers sont en general inclines au couchant sous un angle plus oumoins ouvert, et ils renferment # * plusieurs couches de pierre a chaux blanche, qui doivent avoir ete formees en m6me temps que le gneiss; car ces deux substances se perdent et se confondent insensiblement l’une dans l’autre.”— Schreiber, Journal de Physique, xxiv. p. 380. De Bournon, Ibid, pp. 202, 430—5. “ La montagne des Chalanches est primitive et composee de roches, dont les unes sont a base simple, et les autres a base m&ang^e. Ces derni&res sont les plus nombreuses; ce sont elles qui constituent particulierement la masse de la montagne. La majeure partie des filons connus se trouve dans une roche quartz- euse micac£e, dont les couches inclinent g^neralement au Sud-Ouest, sous un angle qui varie tres-frequemment. La maniere d’etre des roches, les uns a l*egard des autres, est assez constante. Le granite fait la base de la montagne ; il est feuillete- Souvent il participe de la nature du gneis, quelquefois de celle des roches amphiboliques, et souvent des unes des autres en meme-tems. Les 518 W. J. Henwood, on the Mines of coarse and of porphyritic structure; but, at short- distances from the lodes , the small crystalline masses of felspar and hornblende,—imbedded in the other constituents,—are generally of indeterminate outline and often graduate into the surrounding basis; whilst gneis et les roches micacees sont aussi variees par le grain et la contexture de leur pate, que par la difference de leurs elemens constituans. Ces roches alter- nent fr£quemment avec les roches amphiboliques; souvent elles sont melangees ensemble, et plus souvent encore leur association se presente avec tous les carac- teres d’un granite, dans lequel le mica serait peu abondant. Dans quelques endroits, le gneis contient des pyrites de fer sulfure, et par fois des parties cal- caires, # % * . La couleur du gneis varie extraordinairement: le gris, le jaune, le vert, le blanc, le noir, etc., sont les teintes les plus communes; mais souvent il a une couleur rouge ou rougeatre, qui a fait donner aux rochers qu’il constitute le nom de roches brules. * Ht * Vers le haut de la montagne, on voit des roches quartzeuses et amphiboliques en couches contournees, et replies sur elles-memes; quelquefois les plis et replis sont tres-multiplies dans les memes masses. La cime de la montagne est de roche schisteuse amphibolique veinee de quartz.”— De Thury, Journal des Mines , xx. pp; 43—5, “ La montagne des Chalanches est formee de gneiss, souvent amphibolique, avec des couches subordonnees de diabase. Les gneiss sont varies a l’infini.” Gueymard, Sur la Miner alogie, la Geologic, et la Metallurgie, du dtpartement de I'Isere , p. 120. “ Le gneiss prend quelquefois une texture granitoide sans perdre entierement sa disposition schisteuse.”— De Beaumont, Annales des Mines, 3me Serie, v. p. 10. “ La diabase des Chalanches est formee, en majeure partie, d’amphibole horn¬ blende, d’un vert tr&s fonce, eclatante, largement lamelleuse. Dans certaines parties de la roche, de grands cristaux d’amphibole sont enchevetr^s avec des cristaux plus petits, de maniere a ne laisser au feldspath que tres peu d’espace a remplir. Dans d’autres 6chantillons, au contraire, les cristaux d’amphibole sont nets, presque isoles les uns des autres, et le feldspath en cristaux tres petits en remplit les interstices; quelquefois les cristaux d’amphibole les mieux de- velopp^s sont places a peu pres parallelement les uns aux autres, et par suite la cassure de la roche presente, comme celle du granite graphique, l’aspect d’une mos’aique assez reguliere. # * # “ Le feldspath est toujours en cristaux de petite dimension, d’un blanc de lait, a peine translucide, avec l’eclat nacre un peu gras qui caracterise l’andesite. II est difficile de le separer completement soit de l’amphibole, soit de l’epidote qui lui est toujours associ^e et intimement m6lang6e. * % % “ Cette epidote est vitreuse, transparente, d’un jaune verd&tre p≤ elle est en aiguilles d^liees, groupees confusement avec les lames du feldspath.” Lory, Bulletin de la Socitte Geologiqxte de France , 2e Sdrie, vii. pp. 540-4. Chalanches d*Allemont, in France . 519 elsewhere they form distinct and perfect crystals.* The beds present considerable undulations; but, on the whole, their direction is about meridional, and they dip towards the west. Near Allemont, on the east, the gneiss is overlaid by hornblendic slates.f The discovery of native-silver, by a goatherd whilst searching for a strayed kid, in 1767, J induced opera- * “ Both in granite, and elvan, a well-defined porphyritic structure is a most unpromising character; whilst a gradual blending of the included crystals with the basis of the rock, is, in both cases, considered an encouraging appearance.” Henwood, Cornwall Geol. Trans., v, 225. f u Au pied de la montagne des Chalanches, pres du Village d’Allemont, on trouve aussi des petites cotes de schiste et d’ardoise calcaire.” Schreiber, Journal de Physique, xxiv. p. 388. De Bournon, Ibid, pp. 203, 431. “ Au tiers de la hauteur * # * on voit trois couches de calcaire primitif qui alternent avec des roches granitiques, micacees et amphiboliques. Ces couches sont inclinees de 60° a l’Ouest; elles sont dirigees du Nord au Sud. A peu de distance de la, on trouve des roches feld-spathiques blanches, contenant des grenats, au-dessous des roches granitiques avec des tourmalines, et enfin en descendant a Allemont, la juste position du calcaire secondaire sur les roches primitives.”—D e Thury, Journal des Mines, xx. p. 45. “ La gorge occidental appelee le Clos du Chevalier, presente un sujet d’etude interessant, l’existence d’une couche de houille seche, dite anthracite, entre les couches d’argile schisteuse a empreintes vegetales, deposde sur une breche granitoides; celle-ci recouvre immediatement les roches primitives de gneis ou amphibole, qui recelent les filons d’argent.”— Ibid , p. 48. De Beaumont, Bulletin de la Societe Geologique de France, 2e Serie, xn. p. 584. “ Vers le bas de la montagne, pres de l’Eau-d’dle, les roches sont de schistes talqueux et micaces, avec des grenats en tres-grande quantite, Ces terrains sont reconverts sur les flancs inferieurs par les calcaires ardoises du lias, et au- dessus des exploitations des Chalanches par un lambeau de gres a anthracite.” Gueymard, Sur la Mineralogie, la Geologie, et la Mitallurgie de Vlsere, p. 121. “ Les diorites schistoides paraissent aussi en liaison bien plus intime avec les terrains de cristallisation, et appartenir a la meme formation que les gneiss avec lesquels ils alternent.”—L ory, Bulletin de la Societe Geologique de France, 2e Serie, vn. p. 540. J The discovery is stated by M EH recto^o f' t he ne s | ( Journal de Physique, xxiv. p. 381), to have been made in 1767 ; „ M. Alexandre Brongniart (Traite de Mineralogie, ix. p 260), „ 1763; 4c ,, M. Gueymard ........ {La Mineralogie, §c. de VIsere, p. 122), ,, 1768. c c c c « 520 W. J. Henwood, on the Mines of tions, which in process of time have extended feet. from (642 toises * * * § or 1251 metres) 4107 to (1514 metres) 49671 above the plain, or (. 1951 X „ ) 6401 ,,(2214 „ ) 7264+ „ sea; and necessitated the erection of dwellings and work¬ shops on the mountain-side. Amongst the principal lodes wrought at Chalanches § are— the Freiddan, which bears 25° S. of E.—N. of W.,|| and dips towards the S.W.;— „ Cobalt, 99 30° W. of N.—E. of S., „ N.E. — „ Simeon , $P 35° W. ofN.—E. of S., „ N.W. — „ Prince, { 20° W. of N.—E. of S., „ E. — 99 ( 20°N. of E.—S.of W., „ N. — „ Hercule, V 20° W. of N_E. of S., ,, E. — ,, Pirou , 99 25° E. of N.—W. of S., „ S.E. & N.W.; and the Ste. Hdiene, 99 20° W. ofN.—E. of S., „ W.; beside a much greater number of smaller veins. In one part of its course, the Prince lode assumes— and thenceforward maintains—a bearing at about a right-angle to its previous direction (Table XVI .)\f (1.) Of the eight several directions—all, more or less, oblique to the Alpine chain— 6 (or 0*750) range from S. of E.—N. of W., whilst 2 ( „ 0*250) „ N. of E.—S. of W., the mean strike being about 33° S. of E.—N. of W. * Schreiber, Journal de Physique, xxiv. p. 381. f De Thury, Journal des Mines, xx. p. 45. J Gueymard, La Mineralogie, la Giologie, et la Metallurgie de I'Isire, p. 207. Ante, p. 517, Note*. § “ M. Schreiber a laissd, non*seulement des plans minutieusement exacts de ses travaux souterrains, mais encore des notes, etats et mentions de la nature et de la qualitie des minerais qu’ilrencontrait dans ses fouilles.”— Lefebvke, Notice sur les minerais et usines des Chalanches d’Allemont (1853), p. 5. |1 In 1840 the magnetic declination at Bourg d’Oisans was about 20°. Hansteen, Phil. Trans., cxxxix. (1849) p. 208. Sabine, Ibid, PI. XIV. “ Whether this deflection is occasioned by the interference of another vein, the works in the neighbourhood are insufficient to show.” Captain Thomas Blamey, Manager of the Mines, MSS. Chalanches d’Allemont, in France . 521 (2.) The dip—often less than 50°, but seldom more than 70°—is, on the whole, much lower than that of productive lodes in general. Of the eight series 4 (or 0*500) are towards the N. & E.;— 2 („ 0*250) „ N. & W;— 1 ( „ 0*125) is towards the S. & W.; and 1 ( „ 0*125) dips towards opposite points in different parts of its course. (3.) Although the lodes generally measure but a few inches, and average less than a foot, they are, now and then, for short distances, as much as two feet and a half, in width. ( 4 .) The principal earthy ingredients of the lodes, are—as in other districts,—much the same as those of the adjoining rocks; but they affect different propor¬ tions, and are mixed with other substances.* Thus * “ Les gites de mineral de la montagne des Chalanches sont de vrais filons et des couches minerales, mais de peu d’5tendue. * * * On n’en connoit que deux ou trois qui aient eu 40 a 50 toises (42*6 to 53-2 fathoms) de longueur sur 30 (about 32 fathoms') de profondeur et de largeur; et c’est ce qui a fait dire a plusieurs Mineralogistes, que le mineral ne se trouvoit aux Chalanches que par nids et par rognons ; ce qui pouvoit d’autant plus s’accrediter, que l'on trouve assez souvent a la surface de la montagne des peitites veines qui n’ont que quelques toises de longueur ct de profondeur, qui fournissent la mine la plus riche et de l’argent natif, et qui tarissent avant qu’on soit parvenu a en ramasser quelques quintaux. “ Yers l’interieur de la montagne, les filons et couches minerales ont un peu plus de suite, ils n’y sont pas moins riches que vers le jour, mais ils sont moins nombreux. * * * “ Les filons et couches disparoissent sous differentes circonstances; ou leur 5paisseur diminue jusqu’a ce qu’il n’en reste plus de trace dans le rocher; % * % ou ils se perdent dans un rocher brise et fracasse. “ Les gites de mindrais d’argent * * * se trouvent tous dans un district qui k environ 300 toises (some 320 fathoms) de longueur et 250 toises (266*2 fathoms) de largeur. Quoique ces gites soient assez pres les uns des autres, il 522 W. J. Hen wood, on the Mines of felspar, quartz, and calcareous-spar always abound; n’y en a cependant que peu qui se joignent ou se croisent; ils sont, pour la plu- part, separes les uns des autres, et pour ainsi dire isoles dans le rocher. On n’a point trouve jusqu’a present de filons nobles plus avant dans la montagne que 100 toises-en ligne horizontale depuis le jour. “ Rien de si bizarre et de si irregulier que les filons et couches minerales des Chalanches dans leur direction et leur inclinaison, II est tres-rare qu’un filon conserve la merae direction et la meme inclinaison dans une etendue de 6 a 8 toises (6‘5 to 8-5 fathoms); ils se jettent tantdt d’un cot6, tantot de l’autre. Les couches minerales y sont un peu plus constantes que les filons, parce qu’elles suivent les bancs de rocher qui les renferment, au lieu que les filons les coupent. II y a autant de differences dans la direction des filons des Chalanches, qu’il y a de divisions sur la boussole du mineur, et leur inclinaison varie depuis 5° jusqu’a 70°. Cependant les couches minerales qui se maintiennent le mieux, sont celles qui ont leur direction du sud au nord, et dont l’inclinaison est occidentale ; et les filons qui se soutiennent le plus sont ceux qui ont la meme direction, mais dont l’inclinaison est orientale. “ L’ochre martiale constitue la majeure partie les filons d’Allemont, qui ont depuis 1 jusqu’a 12 pouces d’epaisseur. % % % Une moindre partie de nos filons est composee de spath calcaire; et % * * dans l’interieur des Chalanches, et principalement dans le voisinage des filons, le gneiss est entremele de parties calcaires ; propriete que le gneiss n’a pas a la superficie de la montagne. “ Le schorl vert [? epidote] sert aussi quelquefois degangue aux filons riches en minerai d’argent; on trouve meme de temps a autre ce m6tal natif dans le schorl. “ Enfin, l’asheste etl’amiante sont la derniere variete de nos gangues. “ Les filons qui consistent en un terre argileuse gris&tre, sont ceux qui en- couragent le moins le mineur. “ Si la direction, l’inclinaison et l’etendue des filons sont bizarres, leurs pro- duits ne le sont pas moins. 11 arrive assez souvent, en les poursuivant, qu’on decouvre des rognons extremement riches, et qu’a 1 pied plus loin iln’y a que de la mine d’une mediocre valeur. Un essai d’un filon nouvellement decouvert contenant 60 a 80 marcs d’argent au quintal [0-300 to 0*400 its weight] ne donne pas plus d’esperance que s’il n’en contenoit qu’un seul marc [0-005] ; car on sait, par l’experience journaliere, que ces filons ne se maintiennent pas dans l’6tendue d’une toise dans le meme etat. * % % Les productions des filons des Chalan¬ ches sont trls-variees. J’ai dejet observe que j’ai decouvert un indice d’or dans une pyrite cuivreuse. La majeure partie du minerai d’argent consiste en une terre ferrugineuse. “ L’argent se trouve, natif en filets contourn^s, et en lames, dans differentes gangues. Le spath calcaire en est souvent pdnetre, et plus souvent l’argent vierge y est niche dans les cavites avec un mulm noir ou mine d’argent noire en poussiere. Quelques-uns des 6chantillons de spath calcaire penetres d’argent natif, etoient accompagnes de cinabre. % * * Une seule fois, j’ai decouvert dans cette exploitation de la mine d’argent corn^e cubique, couleur de foie dans Chalanches d’Allemont, in France. 523 hornblende is, perhaps, less plentiful; but chlorite, un mine de cobalt terreuse, oil elle etoit accompagn6e de parcelles de mines d’argent rouge et entourree d’argent natif. “ Les mines d’argent vitreuses, rouges et grises n’y abondent pas. # # * “ La mine d’argent rouge est quelquefois renfermee dans de l’asbeste, et la mine d’argent grise dans du schorl vert. Cette derniere contient depuis 20 jusqu’a 40 marcs d’argent au quintal (0010 to 0.020). En general les crystallisations de minerai et des metaux sont extr£mement rares aux Chalanches. “ II ne s’y trouve que peu d’£chantillons de mine de cuivre jaune, et de mine de plomb en galene; la derniere donne un marc et quelques onces d’argent au quintal. “ La mine d’Allemont jouit d’une grande reputation, a cause de ses beaux morceaux de mine de cobalt terreuse, dont quelques especes sont connues sous le nom de mine d’argent merde-d’oie. La mine de cobalt ne s’y presente qu’ accidentellement et par echantillons: jamais elle ne constitue des filons un peu suivis; elle s’y trouve ordinairement parmi le minerai ferrugineux, quand il est bien riche en argent. % % % La mine de cobalt grise arsenicale est la seule de nos mines qui soit pauvre en argent; mais elle est encore plus rare que les autres especes. # % * Sur cent quintaux de mine d’argent qu’on y extrait, il y a d peine vingt Ibres (0 002) de cobalt de l’espece dont je viens de parler. * * * “ On a trouve aux Chalanches presque tontes les especes de mines de cobalt. La plus remarquable est celle que l’on connoit sous le nom de mine de cobalt noire ou vitreuse; elle est souvent traversee par des lames d’argent, et contient 20 jusqu’a 80 marcs (0 # 100 to 0*400) de ce metal au quintal. “ Les autres especes de mine de cobalt terreuse sont plus ou moins riches, et remplies de filets d’argent capillaires; il y en a meme qui donnent a l’essai 72 marcs (0-360) per quintal. J’ai aussi trouve du cobalt gris noiratre avec des parcelles de mine d’argent rouge dans une gangue de schorl vert; et dans le Kupfer-Nickel, j’ai trouve un indice d’or. # # # Schrbiber, Journal de Physique, xxiv. pp. 381—7. “ Les minerais des Chalanches sont disposes en filons, en couches et en rognons. Les filons varient a l’infini; ils n’ont aucune maniere d’etre uniforme : leur puissance, leur direction et leur inclinaison, eprouvent des variations continu- elles, et sont sujettes a un grand nombre d’accidens. Ces filons sont generale- ment places les uns au-dessus des autres; ils sont voisins, tres-rapproches; ils se croisent en tous sens; ils ne conservent ni direction, ni inclinaison, ils prennent frequemment une marche opposee a celle qu’ils tenaient precedemment; enfin, ils se reunissent, ils marchent quelque terns ensemble; ils se s^parent pour se reunir de nouveau ou pour disaparaitre entierement, et avec des circonstances tres-differentes. La richesse des filons ne se maintient pas mieux que leur maniere d’etre. On voit souvent des filons qui donnent 20 et 25 d’argent pour D D D D 524 W. J. Henwood, on the Mines of talc, mica, epidote, and asbestus occur, here and there, in smaller quantities. Calcareous-spar, chlorite, asbestus, and epidote have been found more or less kindly vein-stones; but earthy 100 de minerai, ne presenter, a quelques decimetres de distance, que des gangues steriles. “ Les couches de minerai sont plus rares que les filons ; elles n’ont que peu de suite; elles eprouvent les memes accidens. Leur richesse, leur direction, leur inclinaison, leur puissance, etc., varient continuellement; elles sont sans cesse coupees, rejetees, etranglees et interrompues par les filons; enfin, & # % je suis porte a les regarder plutot comme des filons horizontaux, que corame des couches veritables. “ Les rognons sont moins nombreux que les filons, # # %. “ La gangue est encore plus variee que la maniere d’etre; le plus commun6- ment c’est la chaux carbonatee ; elle se trouve pure, melangee, associee, cristal- lisee, informe, etc. Quelquefois, c’est la chaux sulfatee; en d’autres endroits, c’est l’asbeste-amiante; souvent, c’est le quartz hyalin, % % % par fois la gangue est argilo-calcaire: ici c’est le talc-clorite pulverulent vert ou brun; plus loin le meme est en masse, et contient de l’argent natif. Souvent c’est l*6pidote en masse ou cristallis6. “ Parmi les gangues metalliques, nous trouvons l’oxyde de cobalt terreux et vitreaux, les cobalts arseniate, arsenical, gris, et tout plus ou moins argentiferes. “ Les nickels arsenical et carbonate font frequemment l’oflice de gangue. Le premier est meme, par fois puissamment riche en argent. L’arsenic se trouve egalement dans les minerais argentiferes. “ L’antimoine s’est trouve dans les etats natif, sulfure, oxyd£ et hydrosulfure. “ Le cuivre, qui est tres-abondant dans les filons, se trouve en differens etats ; il est pyriteux, sulfure, carbonate vert et bleu. Le cuivre gris se trouve trfes- frequemment dans l’asbeste, ettoujours il est tres-riche en argent. “ Le fer et le manganese, l’un et l’autre oxydes, sont generalement repandus dans les filons; le dernier presente meme une des plus riches gangues en argent. “ Le plomb se trouve a l’etat sulfure, et quelquefois a l’etat phosphate.” Hericart de Thury, Journal des Mines, xx. pp. 45—8. “ Les minerais d’argent de la montagne dont on vient de rappeler la constitu¬ tion geologique, sont disposes en veines, rognons, amas et filons, toujours irr^guliers et de peu d’etendue. Ces gites sont tres-rapproch^s les uns des autres, souvent paralleles, puis se coupant bientot sous toutes sortes d’angles, changeant a chaque instant de puissance, de direction, d’inclinaison et de richesse. Ainsi on trouve l’argent massif et natif, puis des minerais rendant 50 pour cent de ce metal, et quelques instans apres les tresors disparraissent et sont remplaces par des gangues sterils. Les changemens brusques s’operent souvent dans moins de trois pieds de longueur de galerie, ce qui a toujours aussi rendu Sexploitation Chalanches cTAllemont, in France. 525 brown iron-ore—whether in small isolated masses and short, thin, veins, or mixed with other substances—- is, by far, the most congenial matrix to ores of greater value. The produce has consisted principally of native silver,* * * * § and of the vitreous,f earthy black,J and red § ores of silver; from time to time, however, small quantities of horn-silver || have been obtained. These irr6guli&re dans ses produits. On conqoit effectivement que l’atelier peut rester six mois, un an et plus sans donner de l’argent, puis dans vingt-quatre heures on trouve largement de la mati&re, non-seulement pour payer tous les frais passes, mais encore pour faire face a de semblables chances. “ Les Chalanches ont produit:—1.° L’argent natif; 2.° l’argent antimonial; 3.° l’argent antimonie sulfure ; 4.° l’argent sulfure; 5.° l’argent muriate. * * * Chaux carbonatee, chaux carbonatee ferro-manganesifere, chaux carbonatee manganesifere, chaux sulfatee, baryte sulfatee, quartz, quartz jaspe, grenat, feldspath, tourmaline, axinite, e^idote, amphibole, peridot, mica, asbeste, souffre, anthracite, or, mercure, plomb, cuivre, nickel, fer, manganese, zinc, cobalt, antimoine, arsenic, et titane siliceo calcaire.” Gueymard, Sur la Mineralogies la Geologie, et la Metallurgie de VIsere, pp. 121—2. * Schreiber, Journal de Physique, xxiv. p. 385. De Bournon, Ibid, p. 203. Haiiy, Traite de Mineralogie, nr. p. 387. De Thury, Journal des Mines, xx. p. 83. Brochant, Traite Elementaire de Mineralogie, n. p. 118. Alex. Brongniart, Ibid , ii. pp. 249, 260. Mohs, Treatise on Mineralogy , n. p. 436. Gueymard, La Mineralogie, &c., de VIsere, p. 121—2. Lory, Description d'une collection de Mineraux formeepar M. H Heuland, ii, pp. 324,—5,—6, f Schreiber, Journal de Physique, xxiv. p. 385. De Thury, Journal des Mines, xx. p. 84. Mohs, Treatise on Mineralogy , in. p. 12. Gueymard, La Mineralogie &c., de VIsere, p. 112. % Schreiber, Journal de Physique, xxiv. p. 385. Brochant, Traite Elementaire de Mineralogie, n. p. 113. Phillips, Mineralogy (Third Edit.) p. 289. Mohs, Treatise on Mineralogy, n. p. 436. Table XVI. § Schreiber, Journal de Physique, xxiv. p. 385. De Bournon, Ibid, p. 204. De Thury, Journal des Mines, xx. p. 85. Brochant, Traite Elementaire de Mineralogie, ii. p. 146. Mohs, Treatise on Mineralogy , in. p. 42. Gueymard, La Mineralogie, &c., de VIsere, p, 122. || Schreiber, Journal de Physique , xxiv. p. 385. De Thury, Journal des Mines, xx. p. 84. Alex. Brongniart, Traite Elementaire de Mineralogie , II. p. 257. Gueymard, La Mineralogie, &c., de VIsere, p. 122, W. J. Henwood, on the Mines of 5 2G are—often together, but sometimes separately—im¬ bedded in, or mixed and invested with, earthy cobalt # and cobalt bloom ; f and all—with smaller proportions of arsenical cobalt,£ arsenical nickel,§ and the arseniate of nickel,||—are enveloped in the ordinary vein-stone. Various ores of antimony, lead, and copper are also thinly scattered through the same matrix, but, hitherto, the deepest have been found the least productive parts of the lodes.^i (5.) The Brisee (cross-) vein —differing in direction from some of the lodes less than they differ from one another—bears 35° N. of E.—S. of W. ; its dip to¬ wards the south — like the mean of cross-veins in * Schreiber, Journal de Physique, xxiv. p. 386. De Bournon, Ibid, p. 204. Haiiy, Traite de Mineralogie, iv. p. 220. De Thury, Journal des Mines, xx. p. 83. Alex. Brongniart, Traite Elementaire de Mineralogie, n. p. 120. Levy, Description d'une collection de Mintraux , m. pp. 247.—9. Table XVI. f Schreiber, Journal de Physique , xxiv. p. 389; De Thury, Journal des Mines, xx. pp. 83, 97. Berthier, Annales des Mines, iv. p. 472. Levy, Description d'une collection de Min&raux , III. p. 262. Table XVI. t Schreiber, Journal de Physique, xxiv. p. 386. De Bournon, Ibid, p. 212. Haiiy, Traite de Mineralogie , iv. p. 203. De Thury, Journal des Mines, xx. pp. 83, 95. Alex. Brongniart, Traite EUmentaire de Mineralogie, n. p. 116. Berthier, Annales des Mines , iv. p. 472. Levy, Description d^une collection de Mineraux,in. pp. 247,—9,—51. $ Schreiber, Journal de Physique , xxiv. p. 387. De Bournon, Ibid, p. 212. Haiiy, in. p. 515. Brochant, Traite Elementaire, de Mineralogie , ii. p. 410. De Thury, Journal des Mines , xx. pp. 83, 90. Alex. Brongniart, Traite Ele¬ mentaire de Mineralogie, n. p. 209. Berthier, Annales des Mines , iv. pp. 467,— 70,—4. Mohs, Treatise on Mineralogy, n. p. 448. Levy, Description d'une collection de Mineraux, ill. pp. 251,-69. Delesse, Annales des Mines, 4me Serie, xiv. p. 461. § De Thury, Journal des Mines, xx. p. 90. Phillips, Mineralogy (3rd Edit.), p. 284. Mohs, Treatise on Mineralogy, n. p. 448, Berthier, Annales des Mines, iv. p. 472. Levy, Description d'une collection de Miniraux , hi. p. 270. Table XVI. “ Les filons furent beaucoup plus riches vers la surface que dans la pro- Chalanches cVAUemont, in France. 527 Cornwall * * * * § —is at a much higher angle than the dip of any locle in the vicinity; and—like the Cornish cross-veins f—it is wider than the widest lode in the neighbourhood. It consists wholly of gneiss; J softer, perhaps, than the adjoining (Country) rock, but of much the same composition and structure. The cross-vein intersects the Hercule lode , and dis¬ places (heaves) it about twelve fathoms (R. t G.A.) towards the right-hand, and to the side of the greater angle; but it is not seen in contact with any other lode . In the hornblendic slates which succeed the gneiss, near Allemont on the south-east,§ unsuccessful trial has been made of a lode , which—bears 35° N. of E.- S. of W., — dips towards the north,— measures some eighteen inches in width,—and contains disintegrated slate and quartz, sprinkled with earthy black manga¬ nese and specular iron. fondeur.”— Alex. Brongniart, Traits Elementaire de Mineralogie, II. p. 260, * Thomas, Survey of the Mining District between Chasewater and Camborne , p. 21. Fox, Reports of the Royal Cornwall Polytechnic Society , iv. p. 84. Henvvood, Cornwall Geol. Trans., v. pp. 247,—50,-77,—9, Tables CL, — III., — IV .,— VI., Ante, p. 410, Note *. f Henvvood Cornwall Geol. Trans. , v. Tables Cl., — IV., Ante , p. 410, Note *. t “ Les filons % % % sont coupes par une espece de gros filons sauvages, composes de terre argilleuse et de morceaux arrondis de gneiss.” Screiber, Journal de Physique xxiv. p. 382. § In 1853 a resident practitioner with the divining ( dowsing)- rod (la baguette), offered an English party his professional aid, in this part of the district.” Agricola, De Re Metallica, pp. 26—8, Fig. 1. Borlase, Natural History , p. 165. Pryce, Mineralogia Cornubiensis, pp. 113—24. De la Chabeaussiere, Journal de Physique, xxiv. p. 423. llees, Cyclopaedia , xxxvii. (Virgula Divina). Henwood, Mining Review , i. p. 403, E E E E 528 W. J. Hen wood, on the Mines of The mines were wrought at such an elevation, and at so great a distance from every habitation, that, even in summer, the workmen seldom visited their families except on Sundays; during several of the winter months, however, frozen snow of miles in extent, and, at intervals, of many feet in thickness, often impeded, and sometimes, for several successive weeks entirely prevented all, communication with their nearest neigh¬ bours.* In spring the steep and ill-made roads are always injured, and sometimes they are destroyed, by frequent avalanches and the general thaw. It therefore was necessary to collect, at the mines, in summer, all materials, tools, fuel, food, and other things requisite during winter. And in order to avoid unnecessary carriage every utensil was shaped on the plain.j' Of course, such difficulties added materially to the ordinary expense of working. The mines of Chalanches were wrought, and the ores obtained from them were smelted at Allemonfc, from 1767 to 1776 on account of the Government;— „ 1776 ,, 1792 ,, the Compte de Provence (afterwards Louis ,, 1792 „ 1808 „ the Government; xviii.); and more recently, at intervals, by various lessees/}: *“M. Gueymard states that the higher mountains in Dauphine are rarely accessible for more than the last ten days of July and the first week or two of August.”— Forbes, Norway and its Glaciers , p. 257. In May, 1853, a path to the mines was opened through frozen snow; which, in many places, exceeded seven feet in depth. Yet on a leafless tree, in this dreary region, a cuckoo perched in full song. t The smiths’ fires—like those at Monlevade and Cotta Preta in Brazil—were blown by water-blasts. Ante, pp. 219—20. $ Gueymard, La Mineralogie, &c., de I'Isere, p. 122 —4. Chalanches cTAllemont, in France . 529 From 1767 to 1803 the quantity of silver extracted amounted to (9,453 kilogrammes) 25,326*39 lbs. Troy; which—at £3 : 6 : 3 4 per lb.— realized . (2,098,481 francs ) .... £83,939 whilst the general expenditure was .. (1,890,896 ,, ) .... 75,636 In thirty-six years, therefore, the net \ _ . „ o n q * beside the furnaces, machinery and tools, which — having been provided from the proceeds of the ores—were now valued at ( 200,000 „ )....£ 8,000* Subsequent operations, however, were much less successful.* * Gueymard, La Mineralogie &c., de l’Isere, p. 122—4. 530 W. J. Hen wood, on the Notice of the SARK’S HOPE Mine, Sark The island of Sark comprehends two unequal tracts of elevated table-land (Great and Little Sark) connected by a high narrow ridge (the Coupee).* The rocks consist mostly of felspar and hornblende; but actynolite, asbestus, steatite, chlorite, calcareous- spar, and quartz, are, here and there, associated with the other ingredients in imbedded masses or subordi¬ nate veins. In several parts of the island metalliferous deposits have been rather extensively wrought. (, a .) At Port es Sees two (levels) galleries were * “ The little Island of Sercq lies six miles to the east of Guernsey, and is rather more than three miles in length. Its extreme breadth is not more than a mile and a half, and its average breadth not quite a mile. In one part, it is not many yards wide, being nearly divided into two portions, connected only by a high and narrow ridge. % Ht Hi It is a table land, having no declivity to the sea at any part, except a small descent at its northern extremity. Hi Hi Ht The eastern side of the land is pretty uniformly about one-third lower than the western. In a general view the western side is of a trap and schistose formation, and the eastern of a granitic.”— Mac Culloch, Geol. Trans,, o.s., I. p. 13. “ Great Sark and Little Sark form one connected island, the connecting link being a natural causeway, at an elevation of nearly 300 feet above the sea. Ht % Ht Great Sark is rather more than two miles in length from north to south, and Little Sark rather less than a mile. The greatest width of land in the principal island is about 3,000 yards. Hi Hi Hi The whole island somewhat resembles the figure 8; but the upper part of the figure should be much larger than the lower part. Its outline is, in fact, a double loop ; the two loops of different sizes, connected by a short line. Both Great and Little Sark are table lands, and their elevation above the sea is upwards of 350 feet. The ground sinks towards the south, but is everywhere surrounded by lofty perpendicular cliff’s. Ht Hi Hi The predomi¬ nant rock is syenite, and the principal veins are greenstone, with felspar walls. But besides these, there are numerous veins of asbestiform minerals, of serpen¬ tine, and of soft clayey matter, and some strings of quartz. Hi Hi Ht Large quantities of actynolite occur in many parts, and an important vein of serpentine and steatite, with asbestos and talc, has been traced crossing the central part near Port du Moulin.”— Ansted, Channel Islands , pp. 70,—1, 264. Sark’s Hope Mine , Sark. 53 I opened, at different elevations, on a lode , which bears 40° E. of N.—W- of S. * dips N.W. 55°—(55°, varies from three to six feet in width, and consists, mostly of disintegrated felspathic and hornblendic matter, aren¬ aceous quartz, and earthy brown iron-ore; wherein hard angular bodies, as well of felspar and hornblende as of massive quartz, and grains both of iron and of copper pyrites are imbedded at intervals.j\ Within about thirty fathoms two other lodes —of much the same composition—have been slightly ex¬ amined. Both bear 24° N. of E.—S. of W., but one has a northerly, whilst the other maintains a southerly, dip; the first, however, measures at least six, whilst the second is scarcely four, feet in width. The neighbouring rocks abound in felspar, though now and then they contain hornblende also; their structure is usually foliated, and near the lodes they are fine-grained and soft, but within short distances, on either side, they become coarse and hard. ( b .) The only part of the island in which the miner has yet found encouragement is, however, the immediate vicinity of Port Gouray, near the south- south-western extremity of Little Sark; where the rocks frequently contain much chlorite and calcareous- spar, although felspar and hornblende are always * In 1838 the Magnetic declination was about 24° West. Ross, Phil. Trans., cxxxix. p. 208. Sabine, Ibid , PI. XIV. f At Port es sees a large and most promissing lode, contains nodules and small strings of iron-pyrites which afford (0-000306 to 0*000460 their weight) from 10 to 15 ounces of silver per ton.” Johnson & Vivian, Bcport on the Sark Mines (1842), p. 2. 582 W. J. Hen wood, on the their principal constituents. # The southern portions are, somewhat indistinctly, foliated; but towards the north massive structure prevails.')' (1.) Although several lodes crop out in the neigh¬ bouring cliffs,J two only have been examined ; viz.— feet The Silver-lode, which bears 28° E. of N. dips N.W. 66° and measures 1*5—11 *0 in width;— —W. of S., -85°, „ Copper-lode, „ N.E.—S.W., „ N.W. 70° „ 2*5—5*0 „ —75°, (2.) The nearly north-north-easterly and south-south¬ westerly (Silver)-lode maintains a much higher in¬ clination than the contiguous (Copper)-lode or the lodes at Port es Sees which range obliquely to it; much as the cross-veins of Cornwall and Devon main¬ tain, with respect to the tin and copper lodes in their * “ The southern point of the island is formed of a sienite [in which] the felspar is invariably white.”—M ac Culloch, Geol. Trans., o.s,, I. p. 16. “ In the western part of the [Sark] the rock at the shallow adit [14 fathoms from the surface] is a decomposing sienite, which continues down to the 10-fathom level [34 fathoms deep] ; from thence to the bottom of the mine chlorite appears, which is traversed by numerous small veins of peroxide of iron and carbonate of lime. It is remarkable, however, that in the cross-cuts which have been extended a few feet on both sides of the lode, we have invariably found a hard sienitic rock containing an excess of hornblende, but not the least appearance of either iron or lime.”— Prince, Cornwall Geol. Trans., vi, p. 103. “ In Little Sark the rocks are somewhat lower than on the larger division of the island, and there is nothing calling for a special remark till we reach the little harbour of Gouray, where, in former times, vessels were moored, bringing stores from Cornwall for the mines adjacent. % % * Veins [which] in large numbers, cross the axis of Sark at right angles, * * * illustrate the fact, that the older fissures, due to early elevation, range east and west, * * * whilst the modern upheavals range rather in a north and south direction.”— Ansted, Channel Islands, pp. 83, 263,—4. t “ A compact rock, containing masses of felspar, prevails east of the engine- shaft, whereas that in the western part of the mine is foliated.” Prince, Report on the Sark Mines (1839), p. 3. J “ There are three interesting parallel lodes, south of Sark’s Hope lode.” Vivian, Report on the Sark Mines (1838), p, 2. Table XVII. Sark's Hope Mine , Sark. 533 respective neighbourhoods;* * * § and as the approximately meridional lodes of Keweenaw preserve with regard to the lodes of Ontonagon (Lake Superior) to which their directions are either transverse or oblique.')'J (3.) In average width the Silver and the Copper lodes are much alike; but the former is frequently of dimensions which the latter never attains.§ (4.) Although the earthy portions of both the lodes comprehend several ingredients beside those of the adjoining rocks, various parts display characteristic differences. Felspathic matter is everywhere the pre¬ vailing constituent, yet particles, small isolated masses, and short, narrow, strings of calcareous-spar are numerous ; granular quartz—if equally plentiful—is less uniformly distributed ; veins of coarse jaspar occur at intervals; and spheroidal agatine masses, containing many concentric layers of differently coloured quartz, are imbedded in the other substances. Throughout the north-north-east, and for some forty or fifty fathoms deep, towards the south-south-west, hornblende is a component of the Silver lode ; but at greater depths it is substituted by chlorite. || * Henwood, Cormoall Geol. Trans., v. pp. 247,—50,— 77,—79. Ante, p. 410, Note*. f Ante, pp. 408,—10. J At Chalanches, however, the lodes which range mostly between N.N.W.— S.S.E. and N.N.E.—S.S.W. dip at much lower angles than the (Brisee) cross- vein, which bears 35° N. of E.—S. of W. Ante, p. 527, Table ~X.VI. § Henwood, Cormoall Geol. Trans., v. pp. 240—5,—75—6, Tables Cl., CIV., Ante , pp. 409,—10, 532, Table X.VI. || “ The matrix of the lode consists of fragments of the strata, carbonate of lime, milk, rose, and brown quartz, red, green, and white felspar, and in some places hornstone (capel). * * # Below the 10 fathoms level [34 fathoms from the surface] it is composed of chlorite, carbonate of lime, and felspar, with fel¬ spar-clay (prian) on the hanging-wall." Prince, Cornwall Geol. Trans., vi. pp. 101,—3. Of the metalliferous contents of both the lodes iron- pyrites and earthy brown iron-ore are, by far, the most abundant; # but—as in most other places—the latter * “ The lode, as far down as 40 fathoms below the sea [64 fathoms beneath the surface], contains an abundance of brown earthy iron-ore, % % * with no¬ dulated, radiated, argentiferous, arsenical, auriferous, and white and magnetic iron pyrites (mundic ).”— Pkince, Cornwall Geol. Trans., vi, p. 101. Sark's Hope Mine , Sark . 535 disappears at little more than fifty fathoms under¬ ground.* (—a.) From the surface to the sea-level—a depth of twenty-four fathoms—the other metallic ingredients of the Silver-lode consist, in great measure, of salts; but still deeper they are almost exclusively sulphurets.')' At all depths throughout the south-south-west, the ores —as well the salts as the sulphurets—are mostly those of lead ; but at corresponding levels towards the north- north-east, they are, almost without exception, those of silver. The following columns—a brief abstract of Table XVII .—show the relative positions of the different ores. SOUTH-SOUTH-WEST. NORTH-NORTH-EAST. Depths. Minerals. Minerals. Surface \ r Carbonate of lead; Chloride of silver; to 24 Sulphate of lead; Earthy black silver- fathoms ) ( Galena. Galena; Earthy black silver-ore; Antimoniated galena; Vitreous silver; Super-sulphuret of lead; Copper-pyrites; Sulphato-tricarbonate of lead; Earthy black silver-ore ; Yitreous silver; Red silver; Green carbonate of copper; Blue carbonate of copper. 24 to 64 fathoms * Pryce, Mineralogia Cornubiensis, p. 91. Phillips, Geol. Trans, i. p. 25; 11 . p. 117. Weaver, Ibid, v. p. 213. Came, Cornwall Geol. Trans., II. p. 122. Fox, Report of the Cornwall Polytechnic Society , iv. p. 85. De la Beche, Report on the Geology of Cornwall, &c., p. 326. Henwood, Cornwall Geol. Trans, v. p. 206. Ansted, Quarterly Journal of the Geological Society , xii. pp. 149,—52; xin. pp. 243,—6,-9,—51. f “ At the ten fathoms [below the sea] level we found that the bunches of ore which had made and were now making returns in the adits, samples of which produced 37 ounces [0*001133 their weight] of silver to the ton of ore, had altered their mineralized state from the chloride to the sulphuret of silver. At F F F F 536 W. J. Hen wood, on the The proportions of the sulphate of lead and of galena scattered through the carbonate of lead near the surface, and of antimoniated galena, the super- sulphuret of lead, the sulphato-tricarbonate of lead, earthy black silver-ore, silver glance, red silver, and of both the carbonates of copper associated with galena in deeper parts of the lode towards the south-south- west; as well as the quantities of earthy black silver- ore mixed with the chloride of silver above the sea- level, and of silver glance and of copper-pyrites inter¬ mingled with earthy black silver-ore at greater depths on the north-north-east, are in all cases very small. Although all the sulphurets of lead are more or less argentiferous, and rich hunches of silver-ore have been obtained at intervals,* the metallic minerals are, in general, so thinly scattered through their matrix, that the twenty fathoms level the lead, which in the levels above had existed as car¬ bonate, seemed to have altered its state to the sulphuret. At the thirty, nearly the same ore was found, except that a proportion of antimony entered into its composition. At the forty this ore shows a small proportion of ruby silver a sample of which produced [0 009704 its weight] 317 ounces of silver to the ton of ore. A branch of galena, continuous to 15 or 16 fathoms, produced 40 per cent. [0 40] of lead, and 37 ounces [0*001133] of silver per ton of ore. At the fifty west, the lode is divided into two branches, the north branch carried pyrites and silver.” Johnson & Vivian, Report on the Sark Mines (1842), pp, 1—2. The argentiferous lead “ ores produced from 20 to 85 per cent. [0*20—0*85] of lead and from [0*000918—0‘003673 their weight] 30 to 120 ounces of silver to the ton of ore.” Prince, Cornwall Geol. Trans, vi. p. 102; abridged. Ante , p. 121, Note. At Chanarcillo the salts of silver often extend to depths far greater than the bottom of Sark’s Hope ; but they are much more abundant in the shallower than in the deeper parts of the lodes. Ante, pp. 90—3, 97—100,—11,—16—18,— 20—1; Tables III. IV. * A sample of ore obtained some 54 fathoms from the surface yielded at the rate of (0 016225 its weight) 530 Troy ounces of silver per ton. Sark's Hope Mine, Sark . 537 —from the difficulty of (dressing) separating them— they have been sold at low rates.* * * § The ores of silver prevail in the north-north-eastern —whilst those of lead abound in the south-south- western—parts of the lode, and both—conforming, in some measure, to the foliated structure of the adjoining (Country) rock— shoot f towards the north-north-east. Below a certain point in this line of their endlong dip, therefore, the ores of lead are—like their analogues in the great lead-mines of Brittany—overlaid by those of silver.^ Notwithstanding the abundance of various ores of silver, neither native-silver,§ nor ore of either * Large quantities of the lode from shallow parts of the mine,—merely freed from imbedded masses of barren quartz,—were sold at £5 : 10 : 0 per ton. During thirteen months past the ore has been sold at an average price of £10 per ton.— Report of the Sark Mining Company (16th October, 1839), p. 1. t Tregaskis, Report of Cornwall Polytechnic Society, iv. pp. 95—6. Ilenwood, Edin. New Phil. Journal , xxii. p. 157 ; Cornwall Geol. Trans. , v. pp. 41, 54, 87*, 129,—93; vi. p. 145; Ante, pp. 122, 215,—16,—59,—63,—4,—9,—70,—3, -82,-3, 319,-23,-6,-82, 437—8. X “ Le minerai d’argent occupe la region superieure du filon de Huelgoat: il fait suite au minerai de plomb, avec lequel il se confond a la ligne de contact. % % Hf L’argent se trouve a trois etats difierents dans le minerai de Huelgoat; a l’fetat de chloro-bromure, l’argentnatif et de sulfure plombo-cuprifere. Les deux premiers de ces mineraux paraissent etre plus repandus que le troisieme : on les rencontre particulierement a la crete du massif argentifere, sur tout 1’etendue de T exploitation.” Pernollet, Annales des Mines , 4me Serie, x. p. 420. Ante , p. 104. § Pryce, Mineralogia Cornubiensis, p. 50, Jars, Voyages Metallurgiques , n. pp. 101,—21, 380,—3,—93, 402,—96. De Bournon, Journal de Physique, xxiv. pp. 204,—11. Schreiber, Ibid, p. 385. Kirwan, Mineralogy, p. 241. Hitchins, Phil , Trans., xci. p. 159. Daubuisson, Des Mines de Freiberg , III. pp. 58, 210, —11. Alex. Brongniart, Mineralogie , n. p. 257. De Thury, Journal des Mines , xx. pp. 83—4, 90,—5,—7. Berger, Geol. Trans, i. p. 171. De Humboldt, New Spain , hi. pp. 156,-94, 221,—9,—30. Wm. Phillips, Geol. Trans., n. p. 152; Mineralogy (Third Edition), pp. 285,—8. Lysons, Cornwall, ccx. Polwhele, Cornwall, iv. p, 134. C, S, Gilbert, Cornwall, I. p, 218. Came, Cornwall Geol. 538 W. J. Henwood, on the cobalt # or nickel,f has ever been observed in the mine. differs but little from the Lead-lode , either in the nature of its earthy ingredi¬ ents or in the proportions of the iron-ores it contains. At a depth of forty-four fathoms, however, it is slightly veined and spotted with copper-pyrites. (5.) The Lead-lode intersects, but does not (heave) displace, the Copper-lode . Trans., i. pp. 121—4; n. pp. 105,—13,—20. Berthier, Annales des Mities, iv. p. 472. Mohs, Mineralogy, II. p. 435. Michell, Manual of Mineralogy , pp. 20-1. Levy, Description d'une collection de Mineraux, ii. pp. 321—2,—4—8. Fox, Deport of the Cornwall Polytechnic Society, iv. p. 92. De la Beche, Report on the Geology of Cornwall, &c., p. 613. Braun, Annales des Mines, 3me Serie, xviii. pp. 148—50. Daubree, Ibid , 4me Serie, iv. p. 259. Domeyko, Ibid, 4me Serie, ix. p. 445. Henwood, Cormoall Geol. Trans., v. pp. 65, 109,—40, 269; Ante, pp. 76, 90—3,—7—121, 525. Pernollet, Annales des Mines, 4me Serie, x. p. 421. Garby, Cornwall Geol. Trans., vn. p. 87. Gregg & Lettsom, Mineralogy, pp. 240,—4. Salmon, Mining Magazine , n. 83. * Jars, Voyages Metallurgies, n. pp. 493,—5,— 6. De Bournon, Journal de Physique , xxiv. p. 204. Schreiber, Ibid, p. 386. Hitchins, Phil. Trans., xci. (1801), p. 159. De Thury, Journal des Mines, xx. pp. 83, 90,—6. Alex. Brongniart, Mineralogie, ii. pp. 118,—20. Vivian, Cornwall Geol. Trans., i. p. 66. Carne, Ibid, pp. 122,—4. Berthier, Annales des Mines, iv. p. 472. Mohs, Mineralogy, n. p. 454. Phillips, Mineralogy, pp. 279—82. Michell, Manual of Mineralogy, p. 52. Levy, Description d'une collection de Mintraux, n. pp. 324, —8. Fox, Report of the Cornwall Polytechnic Society, iv. p. 92. Braun, Annales des Mines, 3me Serie, xviii. pp. 148,—50. Daubree, Ibid, 4me Serie, iv. p. 249. Henwood, Cornxcall Geol. Trans., v. pp. 66, 478; Ante, pp. 121, 526. Garby, Cormoall Geol. Trans., vn. p. 87. Gregg & Letsom, Mineralogy, pp. 240, 302. fDe Bournon, Journal de Physique, xxiv. p. 212. Schreiber, Ibid, p. 387. Kirwan, Mineralogy, pp. 241,—55. De Thury, Journal Des Mines, xx. pp. 83, 90. Alex. Brongniart, Mineralogie, n. p. 209. Berthier, Annales des Mines, iv. p. 472. Phillips, Mineralogy, p. 283. Braun, Annales des Mines, 3me Serie, xviii. pp. 149,-51. Ante, pp. 121, 526. Sark's Hope Mine , Sark. 539 The water # which enters the mine is fresh above, but salt below, the sea-level.f The engines stand on a wild cliff; and in several of the drifts, extended beyond it, the workmen hear over¬ head—even in fine weather—the dashing of the waves and the grinding of the pebbles. * On the coasts of West Cornwall the mine-water is generally more or less salt. Pryce, Mineralogia Cornubiensis , p. 21. Hawkins, Cornwall Geol. Trans., I. p. 138. Forbes, Ibid, II. pp. 176,—7, —9. Came, Ibid, ii. pp. 337, —9,— 42, —3,—4. Henwood, Ibid, v. pp. 12, 20, 56. At 40 fathoms below the sea in Botallack a small quantity of clear fresh water oozed out of the rock at one spot, whilst all the water around it was salt. As long as it lasted the miners collected it for drinking; but it disappeared in course of working the mine.—F orbes, Cornwall Geol. Trans., ii. p. 177. f Ante, p.535. 540 W. J. Hen wood, on Notices of Copper Mines in Ireland. The ores of copper occur in many parts of Ireland ; but they have never been wrought to advantage except in rocks of the Silurian,* * * § j - Old Red Sandstone,J and Devonian, or Carboniferous,§ periods; in the counties of Wicklow,* Waterford,')' Kerry,J and Cork.§ The copper-bearing rocks of Wicklow, —which have been more extensivelv mined than those in any other part of Ireland,—stretch from Kilmacow, across the deep Vale of Ovoca, to the Aughrim river, || * Smyth, Records of the School of Mines, I. p. 370. f Jukes & Du Noyer, Explanation to accompany Sheets 167, 168, 178, § 179 of the Maps , and Sheet 13 of the Longitudinal Sections of the Geological Survey of Ireland , pp. 59, 82. Jukes, Quarterly Journal of the Geological Society of London, xxn. pp. 323—4. 1 Griffith, General Map of Ireland to accompany the Report of the Railway Commissioners. Haughton, Journal of the Geological Society of Dublin, vi. p. 206, Jukes, Explanations to accompany Sheet 184 of the Geological Survey of Ireland , pp. 24—5, 37. § Griffith, General Map of Ireland to accompany the Report of the Railway Commissioners. Haughton, Journal of the Geological Society of Dublin, vi. p. 227. Jukes, Kinahan, Wynne, & Smyth, Explanations to accompany Sheets 191, 197, # 198 of the Geological Survey of Ireland, pp. 7, 20, 30. Jukes, Notes for a comparison between the Rocks of the South West of Ireland, and those of North Devon, and Rhenish Prussia, p. 16. || “ Les mines de cuivre ont dte reconnues dans une etendue de 7 milles d’ Ireland (environ 14 kilometres 4-10) (3) du nord-est, au sud-ouest depuis Kil- macrea jusqu’ a la montagne de Bally Coage.” Journal des Mines, No. xvi. (1795) p. 80. “ In the county of Wicklow, the metalliferous clay slate district occupies but a small space, being very narrow in breadth, and in length not more than ten miles, extending from Croghan Kinshela on the south, through the townlands of Knocknamohil and Ballymoneen, Ballymurtagli, Ballygahan, and Kilcashel, Cronebane and Tigrony, Kilmacow and Connery, towards the West Aston range on the north.”— Weaver, Geol. Trans., v. pp. 207—8. “ The clay slates which form the principal constituent rock of the county of Copper-Mines in Ireland . 541 some nine or ten miles along the beds of slate, which range from north-east to south-west, # and dip towards the south-east. Towards the north-west certain inferior members of the metalliferous series are interlaid by granular beds of felspar and hornblende. These are succeeded by mottled, pale-blue and white, fissile slates, thinly sprinkled with minute crystals of iron-pyrites. The principal portions of the formation consist, however, of homogeneous, dark-blue and variegated clay-slate, of silky lustre; often thinly cloven near the surface, but always of thick-lamellar structure at greater depths.^ This sometimes alternates with thin layers of slightly- laminated, yellowish or bluish-white, argillaceous matter. In a higher part of the system a few thin, Wicklow are not, as a whole, remarkable for the presence of metallic minerals, either disseminated, or in veins; but a band or ‘channel’ of about 600 fathoms in width, coursing from the north flank of Croghan Kinshela for about 9 miles in the direction N. 40° E., exhibits at intervals a variety of metallic ores ; which being in certain spots accumulated in larger quantities than elsewhere, have given rise to the long-continued mining operations in the Yale of Ovoca.” Smyth, Records of the School of Mines, i. p. 370. Mahon, The Mines of Wicklow , p. 35. * In 1840 the magnetic declination at Dublin was about 27° 30' West. Lloyd, Phil . Trans., cxxxix. p. 208. Sabine, Ibid, PI. XIV. f “ La gangue est en general l’espece de schiste argileux que les mineurs nomment killas, et qui est tendre et lamelleux, et l’argile, blanche en quelques endroits, jaune ou noire en d’autres.”— Journal des Mines, No. xvi. p. 80. “ In the eastern bank of the Avonmore the clay slate contains some thin beds of hornstone and felspar porphyry, and to the north-west it rests upon a thick bed of greenstone, that encloses a bed of roofing slate. Beyond the greenstone, clay slate reappears in mass: all these rocks ranging north-east and south-west, and dipping 65° to the south-east. % % % “ Cronebane is flanked on the north-western and south-eastern sides, in Connery and Tigrony, by quartz rock which varies from granular to compact splintery, and abounds in contemporaneous veins of pure white quartz. The interval is occupied in part by pure clay slate, but principally by clay slate in 542 W. J. Hen wood, on crumpled and fissile layers, of glossy black hue, afford, here and there, traces of carbonaceous matter. Above these—in Connorree and Tigrony at least—the clay- slate graduates into a massive siliceo-felspathic rock. The planes of cleavage coincide with the bedding of the rocks ; as well in their north-easterly and south¬ westerly direction, as in their south-easterly dip. almost every stage of union with quartz # * % which graduates at length into a substance which has all the characters of hornstone and even of flinty slate, and these again pass by a series of gradations into pure clay slate; a progression which is repeated likewise on the outer flanks of the quartz rock. These quartzose varieties of clay slate abound in contemporaneous veins of pure quartz, which are more or less metalliferous. % % Ht The clay slate and quartzose slate contain subordinate beds of what are technically called soft-ground. As far as explored they vary from three to fourteen fathoms in width, and extend to an uncertain distance; but some have been traced for more than one hundred fathoms, while in depth they generally become more compact and firm. The soft ground consists of tender decomposing clay slate, varying from a light yellow or grey to a deep black colour, abounding in pyritous patches % % % and generally accompanied by a considerable body of greyish or yellowish white clay. # % & The slaty rocks (whose general range is nearly north-east and south-west, and dip south-east at an angle of 65°) are divided into great beds, by parallel seams or joints, which intersect the in¬ clined planes of the clay slate at right angles dipping 25° towards the north¬ west. These seams are open fissures, which sometimes will admit one or two fingers, and at other times scarcely the blade of a knife. In their progress they pass uninterruptedly through all the beds and contemporaneous veins included in the slaty rocks, dividing them, and sometimes producing, as it were, a sensible alteration in their disposition. This tendency towards a division into horizontal beds (independent of the slaty structure) may also be observed in several parts of the district.” Weaver, Geol. Trans., v. pp. 214—16. “ The slates [in this neighbourhood], which from the fossils occurring near Rathdrum, are referred to the lower Silurian period, are thinly laminated, and very uniform in strike and dip, though differing so much in mineral composition as to pass through many gradations of argillaceous, talcose, felspathic, and greenstone slate. Considered under a general aspect, the hornblendic varieties occur chiefly on the lower or ‘ lying ’ side of the metalliferous portion, whilst the hanging side is occupied, on both sides of the Ovoca, by extensive roughly bedded masses of a felstone, or siliceous felspar rock, which gives rise to most of the precipitous forms between the Meeting of the Waters and the Wooden Bridge.”— Smyth, Records of the School of Mines , i. pp. 370, 408. Mahon, The Mines of Wicklow , pp. 35, 75. Copper-Mines in Ireland. 543 The most noteworthy portion of the formation, how¬ ever, is (the Sulphur-course ) a metalliferous band, which—with few interruptions—conforms, in both bearing and inclination, to the schistose structure of the adjoining strata. # * “ In [the] soft ground are contained one or more layers parallel to each other of copper pyrites, or mere iron pyrites, varying in thickness, and sometimes acquiring a breadth of several fathoms. Ht * % Thin parallel layers of ore are interstratified with the clay-slate.”— Weaver, Geol. Trans., v. pp. 215—16. “ The metalliferous contents, of this remarkable series, are disposed in several groups of straight lines presenting, with a singular degree of parallelism most of the characteristics of bedded or stratified masses, such as their conforma- bility to the beds of the slatey rock of the country, their freedom from vein¬ stone, from ‘ vugs,’ and from crystallized minerals, their laminated structure, and the gradual blending, in most cases, of their ores with the adjoining strata. Yet Hi Ht they appear to cut across the strike of certain beds.” Smyth, Becords of the School of Mines , I. p. 392. “ In the Ovoca district the bed-like appearance of the sulphur-course is com¬ plete.”— Mahon, The Mines of Wicklow, p. 73. “ Throughout its range the sulphur-course has the same underlie as the cleavage-planes of the clay-slate adjoining it.” John Hodge, Esq., Superintendent of the Ballymurtagh Mines, MSS. “ Les pyrites [de Fahlun] sont tresvariees; il en est qui sont tr&s-riches en cuivre, avec ungrain tres-fin et serre; d’autres qui sont purement martiales, encore qui contiennent du fer et du cuivre, et qui out striee, ou plutot d’une configuration schisteuse, comme le schorc avec lequel elles sont melees.” Jars, Voyages Metallurgiques , iit, pp. 34,—7. “ Le terrain de transition des environs de Christiania se compose generalement de schiste argileux, quelquefois alunifere, de calcaire et de grauwacke. Des massifs de granite et de syenite s’elevent au milieu de ce terrain. He He Hi Loin du granite et de la syenite, les couches de transition ne renferment guere d’autre mineral metallique que la pyrite de fer; mais en general, des qu’elles s’approchent du granite, elles acqui&rent des characteres particuliers. Hi Hi H: C’est aussi precisement a la jonction du terrain de transition avec les roches plutoniques, que se trouvent des nombreux amas metalliferes, Hi Hi Hi . Ces amas, de forme tout a fait irr&guliere s’etendent tantot dans la roche plutonique, tant6t, et plus frequemment, dans le terrain de transition: dans ce dernier cas, ils s’allongent ordinairement dans le sens des couches.” Daubree, Annales des Mines, 4me Serie, iv. pp. 232—3. The mines of Rio Tinto, about twelve leagues west of Seville, are wrought in a formation of clay-slate traversed by dykes of porphyry, and it is near the con¬ tact of the schist and porphyry that the deposits of ore generally occur*. The strike of the slates is from east to west, and the dip (except where disturbed by GGGG 544 W. J. Henwood, on Its width varies from about six # to more than seventy f feet. eruptive rocks) north, the angle varying but little from the vertical. The masses of mineral are usually lenticular, and have the same strike as the rocks they traverse. They are sometimes entirely imbedded in the porphyry, at others entirely in the slate ; but most frequently the porphyry forms the northern wall, and the slates the southern one of the deposit. Thomas, Notes on the Mines of Rio Tinto (abridged), pp. 3—4 ; Mining and Smelting Magazine , I. p. 113. “ The Rammelsberg mountain, situate near Goslar, is composed of the three lowest members of the Devonian formation of the Harz—the Wissenbach slate, the Calceola slate, and the Spirifera sandstone. Here, however, their order is reversed, the Wissenbach slate being the lowest and the Spirifera sandstone the uppermost member of the series. The celebrated deposit of pyrites is situ¬ ated in the Wissenbach slate, which forms the base of the mountain, and which here consists of true clay slate, very generally used for roofing purposes. Above Goslar the well-defined cleavage is, as a rule, crossed at an acute angle by a not very perfectly-defined stratification. Whilst on the west slope of the Keppel Valley this divergence between the cleavage and the stratification seems tfc. be the rule, nothing of the kind has been observed at Rammelsberg. There, on the contrary, not only does the large pyrites deposit generally coincide with the cleavage, but a zone of Orthoceratites and Goniatites found under the pyrites is also parallel to the cleavage. It is therefore probable that in the Rammels¬ berg, as far as it consists of Wissenbach slate, the cleavage and stratification coincide. * % *k The body of ore strikes between hours 4 and 5 (E. 15°—30° N.) and its dip varies, but is mostly at an angle of 45° S.S.E. Its length on the line of its direction also varies, and decreases in depth, The width of the un¬ divided mass is reckoned from 35 to 40 fathoms; but at a depth of 62 fathoms, it separates into two branches , one of which wedges out at a depth of 82 fathoms in the hanging-wall , whilst the principal branchy on the foot-wall, goes to a greater depth.”— Von Cotta, Berg-und Hiitten , Zeit, No. 45, 1864. Mining and Smelting Magazine , vn. (1865), pp. 151—4. Henwood, Cornwall Geol. Trans., vi. p. 144; London, Edinburgh , and Dublin Phil. Mag., 3rd Series, xxV; p. 344; Ante, pp. 187, 207. * Table XVIII. f “ There occurred [in Connary], some years ago, a ‘ bunch ’ of ore 72 feet in width.”— Smyth, Records of the School of Mines, i. p. 383. “ Unquestionably the most remarkable lode [in Ballymurtagh] now, is the ‘ Great North Lode.’ On the surface of the hill # % * appears a large bed of gossan, composed of brown haematite iron, which reaches the enormous width of 100 feet. This gossan, which is an excellent iron ore 52 per cent, produce, worth 15s. or 16s. per ton, has been worked as a quarry. Ht Ht * “ At the eighteen-fathom level the ‘ Pond lode ’ is found to be seventy feet wide.” Mahon, The Mines of Wicklow , pp. 51—2. Copper-Mines in Ireland\ 545 Earthy brown iron-ore, sparingly interfoliated with slate, is its chief ingredient to a depth—of seven fathoms at Connorree* on the N.E.;—of a few feet in one bed but of sixteen fathoms in another at Bally- murtagh f on the S.W.;—and still deeper at Crone- bane\ midway between Connorree and Ballymurtagh. In, and immediately beneath, the (gossan) earthy brown iron-ore, towards the N.E., small quantities of galena are, now and then, associated with minute proportions of silver, and sometimes mixed with either blende, the sulphuret of antimony, earthy black copper- ore, vitreous copper, copper-pyrites, or iron-pyrites,§ * Table XVIIT. f “ The Sulphur-course afforded large quantities of yellow copper-ore close to the surface in Ballymurtagh and Ballygahan; but the bach of our Great North Sulphur-course, for about sixteen fathoms in depth, is composed of the peroxide of iron.”— John Hodge, Esq., MSS. t “ In some parts of its course this bed did not produce copper ore till nearly at the depth of forty fathoms from the surface, the upper part consisting princi¬ pally of a brown indurated oxide of iron.”— Weaver, Geol. Trans., v. p. 216. § “ In sinking the shafts at Crone-Bawn the first mineral met with is an iron¬ stone. Beneath this they arrive at a lead ore, which seems mix’d with the clay, yet yields a large quantity of lead and some silver. Under this lies a rich rocky silver-ore, which sparkles brightly, and yields seventy five ounces of pure silver out of a ton of ore, beside a great quantity of fine lead. Having pierced some fathoms thro* this, they arrive at the copper ore, which is very rich.” Henry, Phil. Trans., xlvii. (1751 —2), p. 501. “ Connery contains a bed of ore about four feet thick, consisting of a fine grained intermixture of galena, grey ore of antimony, and blende, with pyrites of copper, iron, and arsenic. % % % A similar compound occurs in the # # # upper [part of] Cronebane.”— Weaver, Geol. Trans., v. p. 215. A newly discovered lode, or bed of sulphur ore, in the Ballymurtagh district, contained a massive mineral, of leaden colour with a tinge of brown. Its specific gravity was 4*4955; but it exhibited numerous intermixed particles of yellow iron pyrites. On its analysis the following results were obtained:— Bisulphuret of Iron,. Fe S 2 , . 24*92 Sulphuret of Iron. Fe S, . 9*33 Sulphuret of Lead, . Pb S, . 19'13 Sulphuret of Zinc, . Zn S, . ' 46*62 100* 546 W. J. Henwood, on and, as in other places under similar conditions,* occasionally with more than one of them. At greater depths, the brown ore is, in some measure, replaced by argillaceous matter, and yet deeper the ores of lead, zinc, and antimony gradually disappear.')' Still down- Neglecting the iron pyrites, which is obviously a mechanical intermixture, the residual constituents are very accurately expressed by the formulae Fe S + Pb S + 6 Zn S. Afjohn, Journal of the Geol. Soc. of Dublin, v. p. 134 (Abstract). “ At Berggieshiibel in Saxony, deposits of this order, containing magnetic iron, copper ores, zinc blende, galena, with garnet, quartz, &c., follow very regularly the strike and dip of the environing clay-slates, the latter varying from 15° to 90° to the north-east. Near the surface were found in place of the above, red and brown ores of iron, with barytes.” Smyth, Records of the School of Mines, i. p. 392. Analyses of ores from Connorree and [of blue-stone from] the Pary's mine.— T.earl ........... Connorree . ... 13* . Pary's. ....... 16* Silver ........... Zinc ........... ... IT* .. . 34‘3 Copper ......... ... 6*1 . Tron ........... 21* .. . 11-9 Sulphur ......... Alumina. ....... ... 3* . Silex . . ....... 7- Water and loss ... 100- 100* MSS. of the late Percival Norton Johnson, Esq., F.R.S.. F.G.S, * “ Dans la contr^e de Christiania # * # on y a trouve les substances minerales suivantes: fer oxydule, fer pyriteux, galene argentifere, blende, pyrite de cuivre, cobalt gris, fer arsenical, bismuth sulfure, molybdene sulfure, cobalt oxyd€, &c.”— Daubree, Annales des Mines, 4me Serie, iv. p. 233. “ The ore [of Eio Tinto] is essentially iron pyrites, but is accompanied by a small per-centage of copper pyrites and some silex, say one or two per cent.; galena and blende are also found in small quantities.” Thomas, Notes on the Mines of Rio Tinto , p. 4. “ At Rammelsberg the mass of the deposit consists of sulphur pyrites, with but a small admixture of copper pyrites. In some localities, however, copper pyrites, galena, and blende are frequent; sometimes even predominating.” Yon Cotta, Berg-und Written, Zeit. No. 45, 1864. Mining and Smelting Magazine, vn. (1865), p. 157. f Ante, p. 545, Note §. Copper-Mines in Ireland. 547 ward the earthy black copper-ore is mostly determined towards the (foot-wall) N.W., whilst the iron-pyrites generally approaches the (hanging-wall) S.E. side.* At the deepest point hitherto attained in this direction, however, iron-pyrites and slaty clay prevail for the entire width; but, notwithstanding small masses and short narrow veins of copper-pyrites occur at intervals, —all trace of separate bedding has disappeared.* Towards the S.W. earthy brown iron-ore forms a crust, of inconsiderable thickness, on the surface of the Sulphur-course; f but at a distance of one hundred * Table XVIII . On the Sulphur-course the peroxide of iron disappears within a few feet of the surface; but on the Great North Sulphur-course—a parallel bed, about one hundred and twenty-five fathoms distant, towards the N.W.—it has been largely worked to a depth of sixteen fathoms. The oxide iron overlies yellow copper- ore mixed with iron pyrites in the former, and iron pyrites sprinkled and veined with yellow copper ore in the latter; but earthy black copper ore has been of rare occurrence in Ballymurtagh and Ballygahan. John Hodge, Esq., MSS. (Abridged.) “ The back of the north lode is characterized by abed of brown haematite, of which an average specimen gave— Peroxide of iron... 74-37 Clay and Silica ..... 11* Water .. 14*12 Volatile matter and loss . 0-51 100 * ” Haughton, Journal of the Geol. Soc. of Dublin, y. p. 281. t At Ballymurtagh “ the surface has been marked by huge projecting masses of * gossan ’ or hydrous peroxide of iron. * % # The great metalliferous deposit % # * consists, at a small depth from the surface, of 12 feet in width of granular iron pyrites, of a pale colour, altogether free from gangue or vein¬ stone. * & & “ About 120 fathoms to the north of the principal vein, large masses of « gossan ’ composed chiefly of fragments of slatey rock cemented by brown ox¬ ide of iron, had long ago induced the commencement of mining operations. It is, however, only within the last three years, that more efficient trials have been 548 W. J. Henwood, on and twenty-five fathoms on the N.W. the Great North Sulphur-course —a parallel band of great width yet unrecognized in other parts of the district—is rich in the same mineral, to a depth of sixteen fathoms.* * Earthy black ore — of which gossan is an ordinary matrix, as well in many another copper region f as in the N.E. of this—is an uncommon ingredient in the S.W.; whilst of vitreous copper, galena, grey antimony, and blende, which had been sometimes obtained in Connorree and East Cronebane , no trace has been yet discovered at either Ballymurtagh or Ballygahan . The portions which immediately succeed the brown iron-ore, in both metalliferous beds, consist mostly of copper-pyrites and iron-pyrites ; but—although the former is, perhaps, rather more plentiful in the Sulphur-course than in the North-course^ —no con¬ siderable part of either is of uniform composition. Notwithstanding the Great North-course and vari- crowned with the success of discovering a parallel course of iron pyrites of re¬ markable size and solidity, # * * the breadth of the new lode averaging 24 feet.” Smyth, Records of the School of Mines , i. p. 372—3. “ The surface of the f Sulphur course * is marked with great masses of ‘ gossan.’ Near the surface the sulphur is twelve feet wide, and this width increases with the depth, in the limit of about eighty fathoms from the surface. “ About 120 fathoms north of the * Sulphur course ’ a bed of ‘gossan * of 100 feet in width is succeeded, at between 20 and 30 fathoms in depth, by the ordi¬ nary sulphur ore.” Mahon, The Mines of Wicklow, p. 60. * Ante , p. 547, Note f. f Pryce, Mineralogia Cornubiensis, p. 88. Henwood, Cornwall Geol. Trans., v. p. 205. Whitney, Metallic Wealth of the United States, p. 322. Ansted, Quarterly Journal of the Geological Society, xii. p. 149; xiii. pp. 241,—8,—9. J “ This formation yields annually about 30,000 tons of iron-pyrites containing about— 0*340 its weight of sulphur, and 0*005 „ copper.” John Hodge, Esq. (1867), MSS, Copper-Mines in Ireland . 549 ous distant portions of the Sulphur-course crop out at different elevations;* iron and copper pyrites, both at Connorree on the N.E. and at Ballymurtagh on the S.W., become predominant ores on nearly the same horizon.f But, beside the ores of iron, copper, lead, zinc, and antimony, traces of virgin silver and of native copper have been observed occasionally; and microscopic particles of gold are thinly sprinkled through many — if not through all—parts of both the Sulphur courses . At Connorree small proportions of gold have been obtained as well from silvery lead-ore near the surface, as from the pyrites at greater depths.J In East Cronehane shallow parts of the Sulphur- course have afforded threads of auriferous silver.^ At Ballymurtagh gold is associated with the earthy brown iron-ore which abounds in the upper portions of both the Sulphur-courses; but the only reliable * The Sulphur-course crops out at Connorree .... about 790 feet above the sea; „ „ Ballymurtagh ,, 430 ,, The Great North > Sulphur-course .. i ” ” ” ” Smyth, Plans and Sections of the Ovoca Mines. f At Connorree the 54-fm. level on the Sulphur-} . . , Anr . - . , ,, * v is about 450 feet above the sea; course ...i ’ ,, Ballymurtagh the outcrop of the Sulphur J 430 Ibid. ii course .. V ” the 16-fm. level on the Great J North Sulphur-course .. ' ” v i» J Journal des Mines, No. xvi. (1795) p. 82. Smyth, Records of the School of Mines, I. p. 389. Mahon, The Mines of Wicklow , p, 63. Postea. j § “ Towards the middle of the last century, a brown indurated oxide of iron, which formed the upper part of a metalliferous bed in the higher grounds of Cronebane, was found to contain minutely disseminated native silver, sometimes in extremely slight filaments, but generally in particles quite imperceptible to 550 W. J. Henwood, on analysis shows that it averages less than (O’OOOOIO the weight) one-third of an ounce to the ton of vein-stone. The more deeply-seated pyritous parts of both forma¬ tions are also auriferous, but in a still smaller degree.* * Earthy matter is much more abundant near the sides f than in the middle of the Sulphur-course. At the eye. The silver was extracted by fusion with lead, and subsequent cupel- lation. It contained about thirty grains of gold in the ounce equivalent to (0'0625 its weight) per cent, and hence, the auriferous silver commonly sold for half a guinea an ounce. Articles made from both the metals so ex¬ tracted are in the possession of a family in the county.” Weaver, Geol . Trans., v. p. 213. Smyth, Records of the School of Mines, i. pp. 380,—9. Mahon, The Mines of Wicklow, pp. 57, 63. * In 1854 a considerable quantity of gossan —[carefully selected from shallow parts of the Great North Sulphur-course in Ballymurtagh] —was submitted to operation in two machines then newly invented for washing gold. The results reported to have been obtained were— d7Vts. grs . in the first machine...at the rate of 17 12 (0 000027 its weight) of gold per ton of ore; ,, second „ .... „ 7 12 (0 000011 „ ) „ ,, ; „ ,, „ another experiment, ,, more than an ounce .. „ „ The Directors of the [Wicklow Copper Mines] Company having little confi¬ dence in such conflicting results from the very same ore, placed other samples of it in the hands of Professor Apjohn, M.D., F.R.S., M.R.I.A., of Trinity College, Dublin, whose analysis showed much smaller proportions of gold than the lowest of those reported by the mechanists. Other experiments were afterwards made at the mine under advice from the late Mr. Evan Hopkins, F.G.S., but the results obtained were even smaller than those of Professor Apjohn. # # * Gold is sprinkled through the iron-pyrites in both the Sulphur-courses; but the proportion is even smaller than in the gossan. % % % John Hodge, Esq., MSS. (Abridged.) f “ The pyrites does not appear to occur in a regular lode or vein with definite walls, but to be diffused through the slate which forms the country in beds, which are stratified conformably with the slate itself; it does not occur pure, but inti¬ mately mixed with the slate.” * Haughton, Journal of the Geol. Soc. of Dublin, v. p. 280. “ The great metalliferous formation * % % [is] not bounded by distinct walls, but ceases by gradual interlamination with the clay-slate. % & & u A large proportion of pyrites is left unworked, in consequence of its being too much mingled with other substances to be available by the processes at present employed.”— Smyth, Records of the School of Mines, i. pp. 372,—91. Copper-Mines in Ireland. 551 intervals, however, slices (horses*) of clay-slate, oc¬ casionally many fathoms in length and height, but often merely a few inches,')' though sometimes several feet, in thickness,—as at Bunna in Kumaon,J Morro Velho\ in Brazil, and at the Buckingham ,|| as well as at the Garnett and Moseley,% mines in Virginia— interlie the ore, ## but such subordinate layers often en¬ close crystalline granules of the neighbouring minerals. Several well-marked lines of structure divide the metalliferous deposit into slightly undulating beds {combs ), somewhat differing—but rarely exceeding a foot — in thickness. In each of these—as in the formation generally — the argillaceous ingredients are less plentiful near the middle than towards the sides. To certain depths much of the ore—like the rock which alternates with it—is so fissile that—even in course of extraction—it cleaves into plates no thicker * Henwood, Cornwall Geol. Trans. , v. pp. 211,—29. t “ At Ballymurtagh # # * extensive workings carried on by the ‘ old men ’ on the copper lode were divided # ^ # by laminae of slates % % % only a few inches thick from excavations in progress on the ‘ sulphur-course,’ where the latter was very wide.”— Smyth, Records of the School of Mines , i. p. 375, Fig, 12.— Mahon, The Mines of Wicklow, p. 92. Table XVIII, % Ante, p. 20. § Ibid , p. 191. || Ibid, p. 378. Ibid, p. 381. ** Table X VIII. ff Pryce, Mineralogia Cornubiensis, p. 95. Werner, Neio Theory of the formation of Veins, p. 83. Weaver, Geol. T?-ans,, v. p. 215. Fox, Report of the Royal Cornwall Polytechnic Society , iv. p. 89. De la Beche, Report of the Geology of Cornwall , &c., p. 339. Henwood, Cornwall Geol. Trans., v. p. 179, 201; Ante , pp. 85,433,—68. Daubree, Annales des Mines, 4me Serie, iv. p. 238. Smyth, Records of the School of Mines, i. p. 383. Mahon, The Mines of Wickloio, p. 61. mum 552 W. J. Henwood, on than roofing-slates,* and exfoliates on the slighest exposure; but still deeper this character gradually disappears, f The confronting sides of many longi¬ tudinal partings — although often uneven — present scored, but glossy, faces of (flucan) unctuous clay. Of the strise short portions may be, here and there, straight and parallel; but for the most part they are crooked and divergent. On opposite sides of the same beds, indeed, they dip, not only at divers angles, * “ The sulphur-ore of Ovoca is easily split into slices as large and thin as the best Cornish roofing-slates; their planes of cleavage coinciding, in both dip and direction, with those of the adjoining (Country) slate-rocks.”— Henwood, Proceedings of the Boyal Geological Society of Cornwall, 9th Oct., 1840; West Briton, 16th Oct., 1840 ; Mining Journal , 24th Oct., 1840. “ It may even be remarked of the masses or ‘ cobs ’ of ore brought to the surface, that when struck with a hammer they have no tendency to break with the usual fracture % % % but split in the direction of the lamination.” Smyth, Records of the School of Mines , I. p. 372. “ In the Ovoca district the # % % ore does not break with the fracture of ordinary copper or iron-pyrites, but splits up like any other tough schist; it has quite a differentappearance when looked at along the plane of the bedding, or across that plane, and the richest qualities pass gradually, and by imperceptible changes, first, into a pyrites containing more schisty matter; second, into what is called by the miners a sulphury killas, containing perhaps 50 per cent, of pyrites; and lastly, into schist, impregnated with less and less sulphur, until finally that mineral disappears.”— Mahon, The Mines of Wicklow, p. 73. “ At Rammelsberg the deposit of sulphur pyrites % % % seems in reality to consist of several more or less lenticular agglomerations separated one from another by thin strata of slate, v: # % The general parallelism of the masses of ore with the cleavage and stratification [of the rock] is in favour of their contemporaneous origin, as well as their inner texture, for in the compactness of the pyrites there is very generally to be observed a distinct layer-like arrange¬ ment, running parallel with the cleavage and stratification. # # * “ The pyrites deposit of the Rammelsberg is by no means a solitary instance. There, are, on the contrary similar deposits at Agordo, Schmollnitz, and Fahlun.” Von Cotta (Berg-und Hiitten, Zeit. No. 45, 1864), Mining and Smelting Magazine, vit. pp. 155—6. f Weaver, Geol. Trans, v. p. 214. Ante, p. 541. Copper-Mines in Ireland , 553 but sometimes towards different points of the compass.* Notwithstanding small local flexures,—the Sulphur- course ,— the layers of slate which interlie it,— the subordinate beds into which it is divided,— and the slices of schistose ore,—all—conforming to the cleavage of the adjoining (Country) rocks—incline towards the S.E. Layers of pyrites, often less than an inch but some¬ times a foot in thickness, accompany the Sulphur-course within short distances, for great part of its range if not throughout the district but whether any of them represent, in Tigrony , Cronehane , and Connorree — N.E. of the cross-course ,—the North Sulphur-course * Henwood, Cornwall Geol. Trans.., v. pp. 172,—82, Tables XVIII. XCV. ; VII. p. 180, Table I.; Ante , pp. 259,—64, 433,—69. f “ Beds of iron-pyrites # % * have appeared in the firm clay slate and quartzy clay slate, in the deep levels of Cronebane and Tigrony. And thin layers and slight threads of copper pyrites and iron pyrites are very frequent.” Weaver, Geol. Trans., p. 216. “ At present five lodes or beds are worked on the Ballymurtagh mine, parallel to each other, and conformable to the bedding of the hornblende and quartz rock of the district.” Hatjghton, Journal of the Geological Society of Dublin, v. p. 2S0. “ On the north of the great metalliferous deposit [in Ballymurtagh] to the distance of 100 fathoms, and on the south for 20 fathoms, parallel veins of cu¬ priferous pyrites have been met with, sometimes very numerously; but only in the case of those which lie within a distance of 50 feet to the south, profitable in extraction. # * * [Between the great metalliferous deposit and] % % % a parallel course of iron pyrites of remarkable size and solidity # # * about 120 fathoms to the north # # % two intermediate lodes have been discovered, one of which offers a good width of iron pyrites with 1^ per cent, of copper, and occasional ribs of higher produce.” Smyth, Records of the School of Mines, I. p. 372—4. (Abstract.) “ In Ballygahan % V; # the coppery rib of the pyrites deposit * % * is succeeded at 9 fathoms farther south by the ‘ main lode,’ (which above the adit level has also a ‘ north branch’), at 2 fathoms again by ‘ Barry’s lode,’ and at 2 fathoms further by ‘ Tuke’s lode.’ ”— Ibid, p. 376. “ On the eastern side of the Ovoca, at the mines of Tigroney and Lower 554 W. J. Hen wood, on which has been, hitherto, wrought only at Ballymur - iagh —on the S.W.—-is yet unknown.* * A few, comparatively narrow, ranges of vein-stone— resembling beds in some, but lodes in other, respects, yet possessing certain characters common to both— maintain the same direction as the laminae of ( Country ) slate, but differ from them, and sometimes indeed from one another, in dip; f whilst certain—hardly parallel veins, of similar composition, are oblique to them as well in bearing J as in underlie. Those which comply Cronebane, the beds of decomposing and variously coloured slates, together with the * sulphur course ’ and the ‘ copper lodes ’ on the south, are evidently the continuation of the deposits of Ballygahan.” Smyth, Records of the School of Mines , i. p. 378. “ At Connary # # * several irregular copper lodes occur on the south, all confined to the silicio-felspathic rock.”— Ibid , p. 384. Journal des Mines, No. xvi. (1795) p. 81. Mahon, The Mines of Wicklow, pp. 49, 55,—8, 62. * “ It is by no means uncommon for lodes to split directly at the point of their intersection by a cross-course or flucan, on one side of which the lode appears in two branches , whilst, on the opposite, but one branch occurs.” Henwood, Cornwall Geol. Trans., V. p. 176. f “ In Cronebane several contemporaneous veins of quartz % % % mostly range and dip with the clay slate, ramifying in their extremities through the rock; or sometimes coalescing again, they form a considerable body, # # # , There are several small ones of this description in Upper Cronebane, and in the lower mine there are six in the vicinity of the Copse and Boundary shafts, and two in that of the Farmer’s shaft.”— Weaver, Geol. Trans., v. p. 216. Table XVIII. X “ The most remarkable of the secondary veins is, first, the « Magpie ’ running N.W. & S.E., 4 to 8 feet wide, and producing copper pyrites and also native copper in quartz; secondly the ‘yellow ore vein,’ coursing from E.S.E. to W.N.W., varying from 18 to 20 inches in width, and affording copper pyrites in a gangue of quartz and killas ; the third is the ‘ copse north vein,’ which runs N, & S., is 8 to 24 inches wide, and contains the same minerals as the last; fourth, the ‘ copse south vein,’ with a width of 18 to 36 inches, and similar ores. The two last are supposed to form a junction with the principal lode on the S.W», where it was found accompanied by a parallel vein which appeared to be Copper-Mines in Ireland . 555 with the first conditions can, of course, meet on their lines of inclination only; # whilst such as scarcely coincide in either their direction or their dip,—bearing generally a few degrees N. of E.—S. of W. and in¬ clining at somewhat different angles towards the S.,— not only interfere with each other in both’ their strike and underlie,f but—slightly converging in their range W.J—approach, and at length become incorporated with, the Sulphur-course.^ The subordinate beds and side-lodes —marked with a family likeness to the Sulphur-course — enclose conformable layers of slate, beside small quantities of—occasionally granular—quartz, spotted sometimes with chlorite,|| and—less frequently—with calcareous on the line of their prolongation.” Journal des Mines, No. xvi. (1795), p. 81 (Translation). Smyth, Records of the School of Mines, I. p. 389. Mahon, The Mines of Wicklow , p, 72. * Haughton Journal of the Geological Society of Dublin , v. p. 2S1. Smyth, Records of the School of Mines, i. p. 372. Postea, p. 557. f Smyth, Records of the School of Mines, I. p. 373. Postea, p. 556. X “ Lodes more frequently split as they go eastward than westward.” Henwood, Cornwall Geol. Trans., v. p. 176. § Smyth, Records of the School of Mines, i. p. 379—80. Postea, p. 556. |] “ Contemporaneous veins of quartz, accompanied sometimes by chlorite, oc¬ cur [in various parts of Cronebane].”— Weaver, Geol. Trans,, v. p. 216. At Ballymurtagh “ quartz spar # * * * * § # composed of sugary quartz, presenting the vughy appearance which is considered by working miners so valuable an indication H: Ht % is of common occurrence.” Haughton, Journal of the Geol. Soc. of Dublin, v. pp. 280—2. “ The copper lode [in Ballymurtagh], although varying much in thickness has none of the characteristic appearances of a vein; its ore is the Hi Hi Hi ordinary copper pyrites, and is of very low per-centage owing to the admixture of iron and of portions of quartz and talcose or sometimes chloritic slate, never occur¬ ring in a fragmentary state, but interlaminated sometimes so delicately as to appear in fine films, and contorted like the adjacent rock.” Smyth, Records of the School of Mines , i. p. 372. IIII 556 W. J. Henwood, on matter.* * * * § Throughout their range they contain con¬ siderable quantities of iron-pyrites; which, to certain depths, are mixed with earthy black copper-ore, and with vitreous copper towards the north-east; f but often give place to yellow copper-ore in the central and south-west parts of the district. Native copper J occurs in most of them; but in minute proportions, and very rarely. Where such layers and veins unite with one another or merge in the Sulphur ^course, whether on their lines of bearing § “ To the south of the Sulphur-course [in Cronebane, and] answering, it is supposed to the South or copper-lode in Ballyraurtagh and Ballygahan, are several quartz veins rich in copper-pyrites, accompanied sometimes with beauti¬ ful specimens of the carbonates, and not unfrequently by chlorite.” Mahon, The Mines of Wicklow, p. 58. * “ I have found also in the lower levels of the copper lode [at Ballymurtagh], carbonate of lime, containing a considerable quantity of magnesia. This occurs in a green greasy slate.” Haughton, Journal of the Geol, Soc. of Dublin, V. p. 580. f Ante, p. 547; Table X VIII. X In the north sulphur-lode at Ballymurtagh “ a quantity of native copper, 28 lbs. in weight was recently found [1853].” Haughton, Journal of the Geol. Soc. of Dublin, v. p. 281. At Connary “ the frequent lining of joints and cracks by a film of crystalline native copper proves that anogenic chemical action, or that which proceeds down¬ wards from the surface, has been rife even to a great depth.”— Smyth, Records of the School of Mines, i. p. 384. Table XVIII. § “ In Cronebane several contemporaneous veins of quartz bearing rich copper- pyrites, accompanied sometimes even by earthy azure copper ore, * * * and whose average produce is ten to twelve per cent, of copper, also occur, and more particularly in the quartzose slate. % # % The union of several such form a considerable body, even twelve feet wide of vein, and four or five feet wide of solid ore; but they seldom continue productive for more than thirty fathoms in length.— Weaver, Geol. Trans., v. p. 216. In Cronebane “ the first < copper lode ’ is sometimes interrupted by a cross¬ deposit of limited length which appears to stop it for a time on its line of strike. Ht He # The ore in general only produces from 4 to 8 and rarely 10 per cent. # * * [but] such ‘ T’s,’ as they are called by the miner, * % * yield for a Copper-Mines in Ireland. 557 or dip, # they commonly yield copper-pyrites on both sides of the contact. Such bodies of ore—often several feet in thickness and sometimes many fathoms in length and height—mostly yield a larger per-centage of metal than the smaller bunches which are imbedded in, and more or less mixed with, sulphur-ore. The Sulphur-course suffers several interruptions. S.W. of East Cronebane the indications, whether of sulphur or of copper ore, are so slight and unpromising, that a line of shallow (Costean-) pits, and a single drift (the Cronebane level), have been thought sufficient examination.f The former extends about three hun¬ dred, the latter—with its flexures and ramifications— more than five hundred fathoms; but neither has been wrought for half a century. After an interval of one length of 8 or 10 fathoms, and heighth of 20 or 30, % * £ copper ore of some¬ what higher per-centage. Smyth, Records of the School of Mines, i. pp. 379—80. (Abridged.) At Ballymurtagh “ a cross-fissure, the sides of which were encrusted with crystallized copper pyrites and quartz, was found between the 33 and 66-fathom levels; with a course nearly at right-angles to that of the main lode, it came up to, but did not pass its north wall. # # % Its width was irregular; yet was sufficient to enable it to be worked * on tribute ’ for some 20 fathoms in length.” Ibid, p. 373. In Ballymurtagh “ the pyrites lode joins the copper lode at about the 56 fathom level, below which there is only one lode, which is worked to a depth of 160 fathoms, the lower part being particularly rich in copper.” Haughton, Journal of the Geol. Soc. of Dublin, v. p. 281. “ The iron pyrites has not been found in available quantity at a greater depth than 100 fathoms; it appears to grow thinner at about 80 fathoms from the sur¬ face, and then to unite with the copper ‘ lodes,’ as they are termed, on the south, forming together at the 56-fathom level a ‘ bunch ’ of copper ore, 24 feet in width. This vein was in one spot by the addition of numerous bands of greater or less thickness, and on both sides, increased to nearly 60 feet. Smyth, Records of the School of Mines, 1 . p. 372. f Weaver, Geol. Trans , v. PI. 12, Plan and Sections of the Copper Mines in Cronebane and Tigrony . Smyth, Plan and Sections of the Ovoca Mines. 558 W. J. Henwood, on hundred and thirty fathoms the surface-works re¬ appear ; * and some thirty fathoms N.W.—on the (R.G.A.) right—of the Cronebane level^ underground- operations have extended, with great, though varying, success, through Cronebane and Tigrony , to the vale. Between the N.E. boundary of Tigrony and the river the Sulphur-coarse is intersected by three cross- (flucans) veins of slaty clay; of which ins. the first bears \ about 10° W. of N.— ) dips E. 50°» & measures some 6 in width: E. of S. ;) —55°; i ,, second t „ 34° W. of N.—) dips E. — i „ 3 : E.ofS.jf N.E. 85°;) feet „ third„ N.—S.; . dips E. 65° \ „ 12 „ —70°; 5 The Sulphur-course is heaved ;— by the first.... 13 fms. (It.—S.A.) towards the right-hand and to the side of the - • smaller angle ; „ second.. 2 ,, (L.—G.A.) ,, left-hand and to the side of the larger angle ; and it abuts on the E. side of the (great) third jlucan; but whether it is represented on the W. by a broad, *“ Towards the N.E., beyond the ‘ Mosey 7 shafts, the strike of the beds appears to have suffered some disturbance; and their continuity is somewhat uncertain, since through a space of 800 feet in length, no workings have been carried on, with the exception of some shallow shafts, long since filled up.” Smyth, Records of the School of Mines , i. p. 380; t “ In West Cronebane the Sulphur-course continued very productive as far towards the north-east as the Government Plan shows a continuance of shallow pits. At that spot, however, it abuts on a joint (Head) similar to many found in this district. Within a range of about five hundred fathoms many trials to recover it have been made in the same direction, but all have been unsuccessful, until East Cronebane is reached; and even here the formation has not been nearly so productive as it was in West Cronebane.”— John Hodge, Esa., MSS. X George Oates, Esq., Superintendent of Tigrony , Working-plan of the Mine , § Haughton, Journal of the Geological Society of Dublin, v. p. 279. Smyth, Records of the School of Mines, I. pp, 378,—94. Mahon, The Mines of Wicklow, p. 76. Copper-Mines in Ireland . 559 though comparatively unproductive, bed about seventy- two fathoms (L.—G.A.) towards the left-hand and the greater angle, # f-by some other band hitherto unrecog¬ nised on the S.y— or by the Sulphur-course wrought —some 287 J—324 # fathoms, or even more,§ distant—* * * § at Ballygahan || in the same direction (L.—G.A.)* is vet undetermined. %) 4 In Ballygahan three neighbouring joints, alike faced with clay, bear 12°—15° W. of N.—E. of S., and— slightly inclining, at intervals, to one side or other— are, on the whole, nearly perpendicular. They all heave the Sulphur-course; the first and second from the N.E., about three fathoms each ;—the third, rather more than four fathoms at one level but to greater distances both above and below for, owing to flex¬ ures, of both the Sulphur-course and the joints, the * Ante, p. 558, Notes $§. t “ In Tigrony the great bed of sulphur-ore is rich to its contact with the cross-course or flucan that runs through the valley. With a view to recovering it, beyond this towards the S.W., long and tedious examinations have been made on both sides. All those on the right-hand have failed to find even a trace of ore; at a distance of about seventy fathoms to the left, however, a metalliferous bed nearly ten fathoms wide has been discovered, but hitherto it has not realized expectation.”— John Hodge, Esq., MSS. $ Smyth, Plan and Section of the Ovoca Mines. § Smyth, Records of the School of Mines , I. pp. 378,—94; PI . II. Mahon, The Mines of Wicklow , p. 76. || Postea, p. 560. U “ About 15 fathoms east of the * Blue shaft’ [in Ballygahan] the ‘ sulphur- lode ’ is heaved a few feet to the north; and 30 fathoms farther, two more dis¬ locations occur, the fragment of the lode being in each case about 2 fathoms long, and separated from the other part about 3 fathoms. Towards the river, it seems probable that the more considerable disruption takes place, which heaves or throws the beds in a horizontal direction to the northward, to Tigroney mine.” * % % . 660 W. J. Henwood, on same heaves respectively are seldom of identical dis¬ tances at different depths; all, however, are towards the left-hand , and to the side of the greater angle (L. G.A.). Between the joints and (flucans) cross-veins which traverse the vale, the Sulphur-course is much less productive* * than in Cronehane and Tigrony towards the N.E., and in Ballygahan and Ballymurtagh on the S.W. Although the produce of various mines has been differently stated,f Official Returns J show that from 1840 to 1866 “ Westward of the engine shaft, 112 feet, the pyrites course is met with by a ‘ slide ’ pointing a few degrees west of north, and is heaved to the south a dis¬ tance of 55 feet, whilst the ‘ copper lodes ’ appear to be unmoved by any dislo¬ cation, and are thus much nearer to the great deposit in the western, than in the eastern part of the mine.” Smyth, Records of the School of Mines , i. pp. 376—7. (t In Ballygahan the flucan-head heaves the Sulphur-course — at the 18 fathom level. 11*4 fathoms, to the left; 30 11 ff 11 50 If . 4*0 >> i) 60 11 » » “ From the surface to the 60 fathom level, the joints are, on the whole, nearly vertical.”— Heney Robinson, Esq., of Ballygahan, MSS transcripts of the Working-plans. “ In Ballygahan three heads or joints,—which bear about 15° W. of N.—E. of S. and dip sometimes W., though perhaps more frequently E., but are on the whole nearly perpendicular,—severally heave the Sulphur-course short distances towards the left-hand,”— John Hodge, Esq., MSS. * “ Near the river the lodes are so entirely broken up by these heaves as to become quite valueless.”— Mahon, The Mines of Wicklow , p. 55. “ In Tigrony the metalliferous bed west of the fucan affords only a few small ribs of sulphur ore.”— John Hodge, Esq.. MSS. f Smyth, Records of the School of Mines , i. pp. 374,—82,—91. Haughton, Journal of the Geological Society of Dublin, v. p. 284. Mahon, The Mines of Wicklow , pp. 53,—4, 98. X Returns from the Custom House (of which those for 1840—52 are quoted by Copper Mines in Ireland . 561 105,432 tons (Avoirdupois) of copper-ore, and 1,960,119 „ „ „ iron-pyrites (sulphur-ore ),— beside very considerable quantities of hematite and earthy brown iron-ore,—have been exported from the district. Mr. Smyth, Records of the School of Mines, i. p. 391; and by Mr. Mahon, The Mines of Wicklow , p. 98) show the shipments at Dublin, Wicklow, and Arklow to have been— Years. Copper- ore. Tons ( Av.) Iron pyrites (Sulphur ore). Tons (4u.) Totals. Tons (At».) Years. Copper ore. Tons (4v.) Iron pyrites (Sulphur ore). Tons {Av.) Total. Tons 1840.. 12,001 42,185 54,186 1854.. 1,063 81,215 82,278 1.. 5,397 81,257 86,654 5.. 185 38,672 38,857 2.. 11,741 42,480 54,221 6.. 415 65,215 65,630 3.. 9,279 41,145 50,424 7.. 135 89,685 89,820 4.. 10,670 36,709 47,379 8.. 47 104,095 104,142 5.. 10,391 40,969 51,360 9.. 27 112,966 112,993 6.. 8,723 37,863 46,586 I860.. 89 109,418 109,507 7.. 5,045 42,533 47,578 1.. 92 78,227 78,319 8.. 4,102 43,301 47,403 2.. 71 75,944 76,015 9.. 4,139 47,908 52,047 3.. 974 66,771 67,745 1850.. 4,545 77,746 82,291 4.. 3,943 73,089 77,032 1.. 2,167 107,560 109,727 5.. 4,225 98,080 102,305 2.. 2,942 102,887 105,829 6.. 1,873 114,153 116,026 3.. 1,151 108,046 109,197 Totals:— Copper-ore.. 105,432 (Avoir.) tons; Iron-pyrites (Sulphur-ore) .. 1,960,119 ,, „ Total.* »• 2,065,551 562 W. J. Hen wood, on For nearly one hundred and twenty years # the mine-water of Ovoca has deposited large precipitates of copper;')' but of the quantities obtained from 1840 to 1866, full particulars are inaccessible. In 1856 the cost of extraction, carriage and ship¬ ment averaged about eleven shillings per ton of sulphur-ore.J The wages of the miners in 1752 . were four shillings a week;§ but between 1840 and 1862 they ranged 1 and ed ) from eleven shillings and sixpence to f v, t 1 twelve ,, „ thirteen shillings . > about ; * Henry, Phil. Trans. , xlvii. (1752) p. 500. •J* The quantity of copper-precipitate (poudre cuivreuse) exported was in 1788 . 11*50 tons, 9 . 37-00 „ , 1790 . 59-75 „ , which yielded on an average 0-328 its weight of metal. Journal des Mines , No. xvi. (1795) p. 85. “ During Mr. Weaver’s management [ ? 1787—1811] the mineral waters flow¬ ing from Cronebane and Tigrony yielded 442-59 tons of precipitated copper (mixed with the oxide of iron) which sold on an average for £27 : 8 : 9 per ton, being in aggregate value £12,126 : 18 : If.” Weaver, Geol. Trans., v. p. 218. Smyth, Records of the School of Mines , i.p. 387. Mahon, The Mines of Wicklow , p. 78. X “ The cost to the different mining proprietors of raising and putting on board the sulphur from their respective mines, is, as nearly as possible, as follows: — Connorree. Cronebane. Ballygahan. Ballymur- Breaking in the mine, drawing to”) £ s. d. £ s. d. £ s. d. tO/Q7t • £ s. d. the surface, and separating from \ 0 4 0 0 5 0 0 3 6 0 5 0 waste...j Carriage f to ^ c k. low in horse-carts.. Arklow by railway. 0 • • 4 • • • 0 • 0 4 0 0 1 6 0 2 0 Dues, agencies, & wear of machinery 0 2 0 0 2 0 0 2 6 0 2 6 Shipping-charges, commission on r sales, &c.J 0 1 6 0 1 6 0 1 6 0 1 6 ^ ton. 0 11 6 0 12 6 0 9 0 0 11 0 Mahon, The Mines of Wicklow , p. 96. There are five hundred men employed in Crone Bawn % % # their pay is eight pence a day.” —Henry, Phil. Trans., xlvii. p. 501. Copper Mines in Ireland. 563 Connorree —situate at the N.E. extremity, and in the most elevated part, of the district, is wrought in clay-slate of which the portion beneath the great metalliferous horizon is generally homogeneous, thick lamellar, and of dark-blue colour; * * * § ** the lower beds are interlaid by a band of felspar irregularly mixed with hornblende; f whilst some of the upper members alternate with thin fissile (? carbonaceous) layers of blackish hue.J The somewhat softer and more cloven slates, which succeed the pyritous part of the series, are of paler tint than those below it; and—especially on approaching the siliceo-felspathic rocks which over- lie them,§—they are frequently mottled with white.|[ The planes of cleavage have, in at least one part of Connorree , a different direction from the average they maintain throughout their range; thus— in the S.W. of Connorree they bear about 20° E. of N.—W. of S.; „ district generally „ ,, N.E.—SW. Their dip is invariably towards the E. or S.E. # * The several metalliferous beds preserve the same * Ante, p. 541. f Weaver, Geol. Trans , v. p. 170. Smyth, Records of the School of Mines , i. p. 370. Ante, p. 541. X Weaver, Geol. Trans., v. p. 215. Smyth, Records of the School of Mines, i. pp. 380,—3. Mahon, The Mines of Wicklow , p. 61. Ante, p. 542. § Weaver, Geol. Trans., v. p. 171. Smyth, Records of the School of Mines, I. pp. 370,—80,—1. Mahon, The Mines of Wicklow, pp. 36, 75. Ante, p. 542. H Table XVIII, column 6. II Weaver, Geol. Trans., v. p. 217, PI. 12. Geological Survey of Ireland, Plan and Section of the Ovoca Mines. Ante , p. 542. ** Smyth, Records of the School of Mines, i. p. 383; Fig. 17, Mahon, The Mines of Wicklow , p. 61. Ante, p. 542. KKKK 564 W. J. Henwood, on strike,* * * § and—with but a single exceptionf—the same inclinations,* as the cleavage-planes of the slates which form their opposite (walls) sides. The deposits most largely wrought are Wall's lode . from 3 to 4 feet in width, the South branch .. . „ 3 „ 4 „ „ , the Sulphur-course .. „ 4 „ . 41J„ „ ; beside several of smaller size, considered unworthy of pursuit. Wall's lode , at a depth of ten fathoms, consists of slaty-clay, granular quartz, earthy brown iron-ore, and friable iron-pyrites, often slightly mixed with, and at intervals enclosing, small masses of, pulverulent black copper-ore. The chief ingredients—the quartz and the pyrites especially—affect distinct beds; and sometimes they encompass and isolate thin conforma¬ ble (horses) layers of slate, identical with the slate (Country) on either side, as well in their composition as in the dip of their cleavage; but—although in¬ clining no more than 50°,§—they never touch it. The South-branch —presenting the same anomaly as the Main lode at Bearhaven,\\ inasmuch as it is more highly inclined than the cleavage-planes of the * Smyth, Records of the School of Mines , i. p. 383,—4. Mahon, The Mines of Wicklow, p. 60, Ante, pp. 543,—53, Table XVIII. f Smyth, Records of the School of Mines, i. p. 384, Ante , p. 554, Table XVIII., Postea, p. 565. % Smyth, Records of the School of Mines, t. p, 383, Ante, p. 544. § Table XVIII., columns 3, 6. [ || Postea, Table XX,, columns 3, 6. Copper-Mines in Ireland. 565 slates in its opposite (walls) sides,*—is in great measure composed of friable iron-pyrites unequally mixed with argillaceous matter; and of granular quartz, either flecked with native copper,')' or thinly sprinkled and slightly veined with vitreous copper and with copper-pyrites ; earthy black copper frequently invests the grey and yellow ores, but sometimes it is also diffused through the earthy matrix. The princi¬ pal constituents form, here and there, ill-defined bands parallel to the underlie of the vein. The Sulphur-course, to about seven fathoms from the surface, affords earthy brown iron-ore in abundance, slaty-clay more sparingly, iron-pyrites in smaller quan¬ tities, and—towards the N.W. wall especially—earthy black copper-ore in even more minute proportions. At greater depths, however, the opposite sides of the deposit assume different characters. The N.W., or lower, portion, contains much friable quartz, quartzose slate, and slaty-clay, more or less mingled with granu¬ lar iron-pyrites; and earthy black copper-ore—often sprinkled through the pyritic part—is sometimes the chief component/); In the shallower levels the pul¬ verulent ore comprehends,—for a width of from four * Table XVIII. columns 3, 6. f Journal des Mines , No. xvi. (1795) p. 81. Smyth, Records of the School of Mines, i. pp. 384,—9. $ “ In 1833 we discovered at the depth of 25 fathoms a hunch of black copper ore, which was worked for many fathoms to a width of more than 40 feet.” MSS. (14th February, 1840) of the late Nicholas Kempston, Esq., sometime Superintendent of Connorree. Smyth, Records of the School of Mines , I. p. 383. Mahon, The Mines of Wicklow, p. 60. Ante , p. 544. 566 W. J. Henwood, on to forty feet,—masses and veins of copper-glance; # but downward—where narrower—it includes also like aggregations of copper-pyrites.f The S.E.,or upper , part of the Sulphur-course in Kilmacow on the N.E., consists, at about ten fathoms deep, of iron-pyrites and argillaceous matter ; showing frequent traces of earthy black copper-ore, and enclosing, at intervals, hunches of galena which has afforded auriferous silver.^ Near the middle of the mine, the iron-pyrites and slaty-clay between the eighteen and the twenty-five fathom levels, enclose small separate masses of argentiferous lead-ore, beside large isolated bodies in which the sulphurets of zinc, lead, copper, and iron—with the sulphuret of antimony at times—are either intimately mixed or chemically combined.§ From the twenty-five to the forty-five fathom level a broad band of iron-pyrites and slaty-clay || remained * Smyth, Records of the School of Mines, I. pp. 383—94. Ante, p. 548. f Smyth, Records of the School of Mines, i. pp. 384,—94. Ante, p. 549. “ The lodes, which yield copper ores in slate # * * * § % are frequently spotted with earthy black copper ore near the surface ; lower down, however, this is succeeded by vitreous copper ; and, at length, by copper pyrites.” Henwood, Cormvall Geol. Trans., v. pp. 228—9. t “ A Connery, tout prks de la grande route, dans la partie du filon qui se dirige vers le nord-est, ce filon s’elargit beaucoup pres de la surface de le terre, et contient une gal&ne a grain d’acier melee de killas, tres-difficile & fondre, qui rend environ 25 p.-§- de plomb, contenant 1 once et \ (0*000905) d’argent par quintal. Le chapeau du filon a offert, en plussieurs endroits, une substance semblable a de l’ocre, qui contenait jusqu’a \ p. (0*005) d’argent, et un peu d’or.”— Journal des Mines, No. xvi. (1795) p. 82. Smyth, Records of the School of Mines, i. p. 389. MSS. of the late Nicholas Kempston, Esq. § Weaver, Geol, Trans., v. 215. Apjohn, Journal of the Geol. Soc. of Dublin, v. p. 135. Smyth, Records of the School of Mines, i. p. 394, Mahon, The Mines of Wicklow, p. 58. Ante, pp. 545,—6. II “ As the Sulphur-smalls of Connorree are largely mixed with clay, and may Copper-Mines in Ireland, 567 unwrought for several years after the underlying body of rich copper-ore* * * * § had been removed. This volume of sulphur-ore is mixed throughout with larger or smaller quantities of several copper-ores; but—as in many other localities f—earthy black ore prevails in the shallower, and copper-pyrites is even more plentiful in the deeper, parts of it. Below the forty-five-fathom level the beds on opposite sides lose, in some measure, their distinctive characters ; the N.W., or lower, layers consisting of iron-pyrites largely charged with argil¬ laceous matter, whilst the S.E., or upper, portions afford isolated bunches of the same sulphur-ore, as well as small bodies of copper-pyrites and still smaller masses of vitreous copper encrusted with earthy black ore, in a matrix of slaty-slay. Within a short distance, however, lenticular aggregations of iron pyrites, and thin beds of copper-pyrites J invested with black cop¬ per-ore, are imbedded in granular quartz interlaid with slate.§ The continuation, at a depth of 84 fathoms, consists of slaty-clay, sprinkled, and sometimes veined, with both sulphur-ore and copper-pyrites,|| therefore be readily made into balls for burning ; they are preferred by the manu¬ facturers to the less earthy smalls of Cronebane and Ballymurtagh John Hodge, Esq., MSS. * Ante. p. 565, t Ibid, p. 566. X Smyth, Plan and Sections of the Ovoca Mines ; Records of the School of Mines , i. p. 383. Ante , p. 556. § Smyth, Records of the School of Mines , i. p. 383, Fig. 17. Mahon, The Mines of Wicklow , p. 61. || Smyth, Records of the School of Mines, i. p. 394. Ante , p. 547; Table XVIII. IT Markham Browne, Esq., Resident Director, and W. G. Roberts, Esq., Manager, of Connorree, MSS, 568 W. J. Henwood, on In shallow parts of the mine the poorer sulphur-ores afforded on an average (0* * * § 000122 their weight) four (Troy) ounces of silver per ton;* but at greater depths the (sulphur-smalls) softer varieties—which are more mixed with clay than the ores of Cronebone , Tigrony , Ballygahan and Ballymurtagh yf — have yielded from (0*000184—0*000582) six to about nine¬ teen ounces.*;}; Gold occurs, not only in alloy with * silver, but in separate grains; * and, in one assay at least, it was obtained in the proportion of (0*000015 the weight §) half an ounce to the ton of ore.*;}; Numberless masses (horses) of slate, frequently less than a foot, though sometimes several feet, in thick¬ ness, and often a few feet only, but occasionally many fathoms, in length and depth, notwithstanding they are bounded—as well above and below as at the sides and ends—by metalliferous ingredients alone, main¬ tain, as a general rule, the selfsame mineral composition as the (country) rocks, which, at the same levels respectively, form the sides (walls) of the Sulphur- course; || yet, now and then, they contain small quan¬ tities of ore. The bodies of iron-pyrites and copper-ore, which envelop these horses of slate, exhibit the same remark- * Ante, p. 567, Note H. f Ante, p. 566, Note || \ “ For some years past the extraordinary and staple comodity of Connorree has consisted of decomposed argentiferous iron pyrites, containing from six to twelve ounces of silver and about half an ounce of gold per ton, and of from one to two per cent, of copper.”— Mahon, The Mines of Wicklow, p. 63. Ante, p. 549. § Table XVIII. 11 Ante, pp. 20, 191, 378,-81, 550,—64; Tables XVIII., XX. Copper-Mines in Ireland. 569 able schistose structure * * * § ** that prevails, to considerable depths, amongst similar ones, in other parts of the Sulphur-course.^ The cleavage-planes, as well of the pyrites and of the slates within it, as of the (Country) rocks above and beneath, J—-maintain the same dip and direction as the Sulphur-course § itself and the horses || it includes. Two series of joints intersect the Sulphur-course ; one,—inclining more highly than it is inclined, but nearly parallel to it in direction—bears 30°—40° E. of N.—W. of S.; the other ranges 22°—27° W. of N.— E. of S., but—unlike the slightly diverging joints in Cronebane ## and BallygahanW — it occasions no displacement. Throughout the district copper is still precipitated from mine-water, but of late the stream from Connorree has been the most productive; for some time, indeed, it acted so strongly on the iron pit-work, that beechen plungers \\ were used, and — as in some parts of * Hen wood Proceedings of the Royal Geol. Soc. of Cornwall (West Briton), 16th Oct., 1840; Mining Journal, 24th Oct., 1840). Smyth, Records of the School of Mines, i. p. 372. Mahon, The Mines of Wicklow, p. 73. Yon Cotta (Berg- und Batten, Zeit. No. 45, 1864); Mining Smelting Magazine, vn. pp. 155—6. f Ante, pp. 551,—2. $ Ibid , p. 564; Table XVIII. § Ibid, pp. 563,—4. || Ibid, p. 564. II Table XVIII . ** Ante, p. 558. tt Ibid, pp. 559—60. $$ “ We have now at work a wooden plunger-pole made of this Country beech, 570 W. J. Henwood, on Cornwall — the pumps were lined with thin slips of pine.* * From the end of September, 1838, to the beginning of April, 1839, about 3,559,358 cubic feet, or 99,312 tons, of water were drawn to the surface.^ This passed from the pump-head, and from one to another of several successively lower tanks, through and we have a second ready for use; both have been soaked in the mine-water, mhich is a capital substitute for Kyan’s patent. The pumps are lined with wood which will save the inside from the action of the water, and the flanges will be protected as much as possible by well tarred hoods of canvass.” MSS. of the late Nicholas Kempston, Esq. In the last century it was suggested to the Admiralty, by the late Captain Hercules Michell, that timber intended for ship-building should be immersed in the water of the great Gwennap adit.” Henwood, Cornwall Geol. Trans „ v. p. 458*, Note 2. “ About the year 1801 [the late] Captain Joel Lean # % % first introduced, at Crenver and Oatfield, (what is now so generally used and with such great ad¬ vantage,) the plunger-pole, instead of the common box and piston.” Lean, Historical Statement of the Improvements made in the Duty of Steam Engines in Cornwall , pp. 8, 9. Smyth, Treatise on Coal and Coal-Mining , p. 181. The late Benjamin Sampson, Esq., of Tullimaar near Truro, and the late Mr. Francis Michell, Engineer, of Redruth, informed the writer,—that, “ in 1796, they had seen the plunger-pole applied at Ale and Cakes in Gwennap, by Mr. Murdock, who then directed the affairs of Messrs. Boulton & Watt in Cornwall; and that they had reason for believing it had been previously worked at another, mine in the neighbourhood.” Henwood, West Briton (xxxi. No. 1606), 23rd April, 1841. * “ When the water is saline or acidulous % % % the working-barrel, ordi¬ narily of cast iron duly bored, is sometimes made of brass or gun metal (as, indeed, it very often was in earlier days) ; or, as in some of the copper mines in Cornwall, the whole of the pump-work may be lined with staves of wood, care¬ fully fitted like an internal cask, to prevent the rapid destruction which otherwise ensues.”— Smyth, Treatise on Coal and Coal Mining , p. 180. t The steam-engine had a stroke of seven feet in the shaft, and—ranging from four to eleven —averaged, during the period under consideration, about seven strokes per minute. The calculated, is assumed to bear to the actual, discharge, the same proportion (1’ to *924) which they bore to one another during repeated experiments at Wheal Towan in Cornwall. Henwood, Transactions of the Institution of Civil Engineers, n. p. 58. Copper-Mines in Ireland, 571 narrow inclined channels (launders). The floors of the former were nearly horizontal, but those of the latter were slightly inclined; the water, therefore, flowed less rapidly through the one than through the other. The capacity of the tanks was about 3447 feet; „ launders „ 900 „ . Both were thickly spread with scraps of wrought iron and shreds of tin-plate, which were frequently turned and swept; in order—by the removal of the precipitated copper—to present a surface of iron as clean as circumstances permitted, to the impregnated mine-water. Accounts kept at the mine show, that during this tons ( Avoir .) the tanks and launders were supplied with about 62-0000 of wrought-iron and tin plate; of which. nearly 20-0000 were consumed; and this precipitated .... 19,9375 of copper, which realized in the market £894 : 10.9. The precipitate was,therefore, 0’9969 the weight of the iron it had replaced; and 0-0002 „ of the mine-water from which it had been obtained. During 1861—2 the consumption of.124 tons of scrap-iron, &c., collected... 60 ,, precipitate, which yielded on an average 0*44 its weight of copper. The precipitate was therefore 0-48 the weight of the iron, and the copper ,, 0 21 ,, ,, The precipitation was always more rapid in running than in still water; and in warm than in cold weather. The water took with it, from the precipitation tanks and launders, a considerable proportion of iron-ochre, most of which subsided in pits prepared for its recep¬ tion ; the rest passed off, in suspension, to the river. LLLL 572 W. J. Hen wood, on At Cronebcine* it appears that in 1862 30 tons of wrought-iron afforded. 12 „ precipitate, which contained 35 per cent, of copper. In this case, therefore, the precipitate was (MOO the weight of the iron dissolved „ copper „ 0-140 „ „ , & „ ,, „ 0*350 ,, of the precipitate. * “ In order to carry off the water from [Crone Bawn] there are levels carried on a great way under-ground, from the lower part of the hill. Out of these levels issue large streams of water, most strongly impregnated with copper. “An accidental discovery, which happen’d not long ago, is like to make these streams more beneficial than all the rest of the mines. Some of the workmen, having left an iron shovel in the stream, found it some weeks after incrusted with copper. This gave the hint of laying bars of iron in these streams, which is done in the following manner: u Oblong pits are dug, ten feet long, four wide, and eight deep: the bottom laid with smooth flags ; the sides built up with stone and lime, with wooden rude beams across the pits to lay the iron bars on. Chains of these pits are continued along the stream as far as the directors please ; for the water never abates of its quality. * * % Soon after the iron bars are laid in these pits, they contract a copper rust, which, by degrees, intirely eats away the iron. The copper, which is in the water, being thus continually attracted and fixed by the iron, subsides to the bottom of the pit. To hasten this dissolution, the iron bars are some¬ times taken up, and the rust rubb’d off them into the pit. In the space of twelve months the whole bar is commonly dissolved, if the iron be soft; for steel or hard iron will not do here. The stream is then turned off the pits ; and the men with shovels throw up the copper, which lies at the bottom like reddish mud. This mud [when] dry becomes a reddish dust # * # . It is then smelted into copper. * * * . “ One ton of iron in bars produces a ton and 19 hundred and an half weight of this copper mud or dust. Each ton of this mud produces, when smelted, 16 hundred weight of the purest copper, which sells at ten pounds per ton more than the copper, which is made of the ore. There are about 500 tons of iron now laid in these pits. The water, that runs from these mines, enters the river Arklow at New Bridge; and is of so corrosive a nature that no fish can live in this large river from hence to the sea.” Henry, Phil. Trans., xlvii. (1751—2) pp. 500—3. According to Dr. Henry’s statement, therefore, the precipitate obtained was 1-975 the weight of the iron used; ,, fine copper „ „ 1*580 „ ,, ; ,, „ ,, ,, 0 800 ,, precipitate. “ L’eau de la mine est toujours plus chargee de la parties salines et metalliques en hiver qu’en ete; ce qui vient, stiivant M. Mills de ce que l’air sec qui circule Copper-Mines in Ireland. 573 The water of Ballymurtagh* gave, from 1852 to pendant l’ete dans les mines, y favorise la cristallisation du sulfate de cuivre, tandis que pendant l’hiver, qui est toujours pluvieux en Ireland, les eaux qui s’infiltrent dans les filons redissolvent les depots salins, et s’enrichissent par-la considerablement. “ On augmente aujourd’hui la concentration de l’eau retiree de la mine, au moyen du minerai pyriteux pauvre. C’est meme presque pour ce seul usage qu’on prend la peine de l’extraire ; car, quoique ce mineral soir le plus abondant, cependant, comme on a vu, on n’en exploite qu’une petite quantite. Apres Tavoir brise en morceaux d’une grosseur convenable, on le met dans les fours qui contiennent, de 50 a 150 tonneaux de minerai. On n’a besoin, pour com- mencer a y mettre le feu, que de quelques broussailles et d’un peu de charbon; apres quoi, le soufre contenu dans le minerai suffit pour entretenir la combustion. Ce soufre, volatilise? par la chaleur, est reeju dans des r^cipiens adaptes a ces fours. & % % Apres que le minerai a ainsi subi le grillage, on le porte dans des fosses remplies d’eau vitriolique, ou on le laisse plonge quelque temps, apres quoi on le passe au bocard; on lave ensuite celui qui en vaut la peine.” Journal des Mines , No. xvi. (1795) pp, 83—5. “ The process [of roasting] commonly lasted six weeks, % # % and when it was well managed, a nucleus of rich yellow or grey sulphuret of copper, sur¬ rounded by brownish red oxide of iron, might be found in each piece of the burnt ore. In this state, the ore being steeped in water, a solution of sulphate of copper was obtained, and the copper precipitated by iron; the kernels of the sulphuret * * * were separated from the slimy oxide by washing.” Weavek, Geol. Trans., v. p. 219. Percy, Metallurgy , i. pp. 439—47. In July, 1791 it was found that the water as it issued from the > con t a j ne( j 000383 its weight of sulphuric salts and 0 00004 its weight of mme .. copper; when it had passed over the calcined ore. after it had rested for some time on cal¬ cined ore in the tanks.. The precipitate contained on an average 0*328 its weight of copper. Journal des Mines, No. xvi. (1795) pp. 84—5. Smyth, Records of the School of Mines , I. pp. 385—9. Mahon, The Mines of Wicklow, pp. 41—2. Ante , p. 562. “ The mine-water of Cronebane contains now (1862) a smaller proportion of copper than it contained formerly.” Captain John Reed, Manager of Cronebane , MSS. * “ II y a deja environ cinquante ans que l’op£ration de cementation est en usage dans les mines de Ballymurtagh, dont l’exploitation, ou plutot la reprise dans les dcrniers temps, a prece de celle des mines de Cronebane. * % ) - } * 0-00962 0 27006 000084 574 W. J. Henwood, on 1861, the undermentioned quantities and qualities of precipitate.* * Precipitate. Precipitate. Years. Quantities of (tons) Prooortion A of copper in Years. r Quantities of (tons) Proportion of copper in 1852 ... 6-0 0-4500 1853 ... continued. 6-0 0-4200 4-5 0-4900 4-0 0-4275 1853 ... 3*0 0-3975 7-0 0-5500 Suivant Berkenhout, l’eau de Ballymurtagh depose par l’evaporation 7 gros et £ de sediment, et celle de Cronebane, 4 gros 16 grains. Journal cles Mines, No. xvi. (1795) pp. 83,—5. “ The water issuing from the pyrites workings [in Ballymurtagh] is strongly impregnated with copper, and on being passed over plates of iron yields a pre¬ cipitate containing from 10 to 30 per cent, of copper.” Haughton, Journal of the Geological Society of Dublin, v. p. 284. Smyth, Records of the School of Mines , i. pp. 386. Mahon, The Mines of Wicklow , pp. 41—5. * John Hodge, Esq., MSS. A comparison of the before-mentioned results with those obtained in other districts, can scarcely be without interest. The enormous body of ore discovered near Amlwch, in Anglesea, on the 2nd of March, 1868,—of which the produce lowered, for some years, the pricfe of copper throughout Europe and threatened the poorer mines of this kingdom with ruin,c—has been wrought in the Parys and Mona mines, without inter¬ mission until now (1868). The blackish and greyish-blue clay-slate, immediately beneath, become more and more quartzose as they approach it: certain portions, transfused with sili¬ ceous matter, displaying a flinty character ; cdef whilst other parts are made up of slate and quartz in distinct and separate laminae ; several large, and exclu¬ sively siliceous, beds of schistose structure of enclose, here and there, bodies of massive quartz ; and broad bands of greyish hornstone cf occur at intervals. The slate directly overlying the ore is generally brownish; but—exhibiting various colours within short distances—it passes gradually into the normal blue. a Pennant, Tours in Wales, Edit. 1810, lii. p. 60. b Journal des Mines, No. xvi. (1795) p. 69. c Hawkins, Cornwall Geol. Trans., iii. pp. 285,—9,-91. d Ramsay, Memoirs of the Geological Survey, iii. p. 195. e Henslow, Cambridge Phil. Trans., i. p. 384. f Erere-Jean, Annalcs des Mines, xiii. pp. 229—35. Copper-Mines in Ireland . o/b Precipitate. . Precipitate. A Years. r Quantities of (tons) Proportion of copper in Years. r Quantities of (tons) Proportion of copper in 1853 ... 6-5 0*5775 1854 ... 2-5 0-4625 continued. 1854 ... 5*5 0-3600 continued. 4-0 0-6537 80 0-3775 1855 ... 0-5 0-1500 Many beds are sprinkled and veined with siliceous substances ; « but these rarely accompany the thick conformable layers of metalliferous quartz which have been largely worked in northern parts of the mines. South of the great metalliferous deposit—where little or nothing of much value has yet been found—the planes of cleavage—maintaining a tolerable regularity —bear nearly E. and W.* In other parts of the district, however, their directions are less uniform : for the average of their many large flexures in the Mona mine, towards the N.E., is 12°—30° S. of E.—N. of W.,—near the boundary of the mines they range about E. and W.,—and in the Parys works, on the N.W., some 15°—25° N. of E.—S. of W. Moreover the wide floor of copper-bearing quartz, worked to a greater or less extent in various parts of both mines—as the Carreg-y-doll “ lode" —is subject to like flexures; and the smaller metal¬ liferous beds—severally known,—as the Clay-shaft “ lode ” and the Charlotte “ lode ” in the E.,—as the North Discovery “ lode ” towards the W.,.—and as the Black-Rock “ lode ” throughout—also conform to the undulations in their re¬ spective neighbourhoods. The relations between the great metalliferous deposit and the rocks adjoining it are not now very readily discerned, its general direction, however, is some 12°—15° N. of E.—S. of W.; * and its dip—like the dip of other productive beds of quartz and the cleavage-planes of the neigh¬ bouring slate—ranges from 50° to 84° and averages, perhaps, 65° towards the N. The formation is intersected by joints of two series; which—differing both from the copper-yielding beds and from the cross-veins (flucans) in direction— bear* 25°-35° W. of N.—E. of S. and 30°-40° N. of E.—S. of W. respectively. Two cross- (flucan) veins traverse the district; namely,—the eastern or Carreg- y-doll cross-course which ranges some 5°—15° E. of N.—W. of S., and the great, or western, cross-course which takes a nearly meridional bearing. Both the cross¬ veins heave the smaller productive beds ( “ lodes ”J they encounter, towards the (L. t G.A.,) left-hand and to the side of the greater angle; c— the Carreg-y-doll cross-course displacing the Charlotte “ lode ” but slightly,—the Carreg-y-doll “lode” about twelve—, and the Black Rock “lode” nearly eight, fathoms; a Frere-Jean, Annales des Mines, xiii. pp. 229—35. b In 1840 the Magnetic declination at Dublin was about 27 a 30' West.— Lloyd, Phil. Trans., cxxxix. p. 208. Sabine, Ibid, PI. XIV. Ante, p. 541, Note *. c Henwood, Cornwall Qeol. Trans., v. p. 287. 576 W. J. Henwood, on Precipitate. .A. Years. ( Quantities of (tons) Proportion of copper in 1855 ... 60 0-4625 continued. 1*5 0-4750 1856 ... 4*0 0-4175 Precipitate. Years. f Quantities of (tons) > Proportion of copper in 1856 ... 3-5 0-4750 continued. 1857 ... 5-0 0-2937 3-0 0-4875 whilst the western cross-course dislocates the Carreg-y-doll “ lode ” as much as thirty fathoms. Both cut through the great metalliferous deposit also; but the extent of any heaves they may have occasioned, is concealed by the rubbish which now covers the sides of the openings wherein it was formerly wrought. The North Discovery (bed) “ lode ” varies from about two to eight feet, the Carreg-y-doll “ lode ” from one fathom to nearly ten fathoms, in width; both enclose conformable (horses) masses of slate; and consist in great measure of quartz, quartzose slate, chlorite, and disintegrated felspar, mixed, however,— with earthy brown iron-ore as well as with smaller quantities of native copper, earthy black copper-ore, the sulphate of lead, and other rare minerals, near the surface,—with yellow copper-ore and specular-iron at greater depths,—and with larger or smaller proportions of iron pyrites throughout. The great metalliferous deposit appears a not only to have occupied the whole space between the Clay-shaft “ lode ” and the Black Rock (t lode ” for a con¬ siderable distance, but also to have extended some way N. of one and S. of the other. It has been wrought open to the day for about 90 fms. on the line of its strike, 1 140 fms. in extreme width ) Hillside open-cast; and more than ) In the ) and „ 210 „ „ „ 90 „ „ „ Great, open-cast: ab to a depth of 18 fathoms, ab and for an area of 5-331 acres, in the former; abc and ,, 23 ,, ,, ,, 12-131 „ ,, latter s ,, and to greater depths, for short distances, in both. The open-casts ac are sepa¬ rated by a body of vein-stone, varying from ten to fifty fathoms in thickness, whence small quantities of copper-ore are still extracted. The principal earthy ingredients—as in the smaller productive beds on the N. —are quartz and quartzose slate, through which chlorite is thinly, and rather unequally, sprinkled; towards the E., however, and especially near the (foot- a Working-plans of the Parys and Mona mines. b Pennant, Tours in Wales (Edit. 1810) iii. pp. 65, 436,-8; Journal des Mines, No. xvi. (1795), p. 73. Hawkins, Cornwall Oeol. Trans., iii. pp. 284,—8. Frere-Jean, Annales des Mines, xiii. p. 229. Amlwch and the celebrated Mona and Parys Copper-mines (Beaumaris, 1848), p. 5. c The open-cast of Wheal Music, wrought on copper-veins, in slate, near Redruth, measures about an acre; „ Carclaze, ,, on tin-veins, in granite, near St. Austell, measures about five acres. Thomas, Cornwall Geol. Trans., v. pp. 98, 120. Copper-Mines in Ireland. 57? Years. Precipitate. JL Years. Precipitate. r Quantities of (tons) Proportion of copper in r Quantities of (tons) * Proportion of copper in 1858 ... 2-5 0-2525 1859 ... 5-5 0-3675 4-0 0-3800 4-0 0-3800 4-0 0-3812 2-5 0-6125 wall) lower side, buff-coloured felspar is also abundant. Thin fissile layers of blackish-blue slaty matter interlie the other constituents, dividing them into ill- defined beds, parallel to the adjoining rocks. Shallow parts of the Mona mine have afforded much (gossan) earthy brown iron-ore, containing nests of earthy black copper-ore, and small cavities incrusted with the carbonates of copper and the sulphate of lead. Beds, laminse, interlacing veins, isolated bodies, single crystals, and disseminated grains of iron-pyrites even yet abound in the quartz- ose and slaty portions of the mass. Galena occurs in some, and blende in other, parts of the formation ; and occasionally the intractable association of both these, with iron and copper pyrites (Blue-stone « ) has been plentiful. Native copper, earthy black copper-ore, vitreous copper, and purple ore have been fre¬ quently obtained; h the principal produce, however, has always been copper pyrites. Great quantities were, of course, scattered through the earthy matrix; but during three months of the year 1787, one party of workmen extracted “ two thousand nine hundred and thirty-one tons of good copper-ore and only ninety-two tons (0-031 its weight) of waste.” o On one occasion forty-four thousand tons of ore lay ready for the furnace. h In both the open-works several large (horses) masses of quartzose slate, interlaid by laminae, and intersected by thin veins, of iron pyrites, have—by the removal of the copper- ore which surrounded them—been left standing as isolated crags. Between the two enormously rich (bunches) portions of the great metal¬ liferous deposit, wrought in the Hill-side open-cast and the Great open-cast respectively, a body of comparatively unproductive—yet slightly orey—quartz¬ ose vein-stone intervenes; whilst—like many of the largest courses of tin and copper-ore in Cornwall, d —each of them is intersected by a cross-vein. Both the cross-veins partake, to some extent, the character of the ore-ground they traverse; for the most part, however, they consist of slate identical, in both composition and structure, with the (country) rocks adjoining : that is to say, a Ante, p. 540. b Pennant, Tours in Wales, iii. p. 61. c Price, Ibid, p. 438. d Came, Cornwall Qeol. Trans., ii. p. 99. Fox, Reports of the Royal Cornwall Polytech¬ nic Society, iv. (1836) p. 88. Henwood, Cornwall Qeol. Trans., v. pp. 32, 233; Tables VIII. XXIV. XLII.,—V., LIU., LX.,—I.,—II.,— V.,— VIII., LXXXL,— VII.,—IX. 578 on W. J. Hen wood, Years. Precipitate. Years. Precipitate. r Quantities of (tons) A Proportion of copper in Quantities of (tons) Proportion of copper in 3860 ... 4-0 0*4425 1860 ... 3-5 0-6125 continued. 4*0 0-4875 1861 ... 3-5 0-3062 5-0 0-5550 3-75 0-3850 # they—as well as several of the Cornish cross-veins —are mere slices of the strata, containing little or no ore. « The richest part of the North Discovery (bed) “ lode ” is intersected, at about right-angles to its course, by two nearly vertical joints ; but the poorer portions are traversed by several such seams ,b all which dip towards the W. The body (courses) of ore,—both in the great deposit and in the North Discovery “lode" —have also a westerly (shoot) dip endlong, but at a lower angle. To a depth of eighteen fathoms in one part, and of twenty-three in another, the great metalliferous mass was quarried for its entire width. At these respective levels, however, “ not only had the body of ore diminished, but it was of lower quality, [whilst] the expenses of raising it had increased inversely in the same proportion, c ” Quarrying was, therefore, discontinued; and mining operations w'ere commenced on the richest of the tributary or subordi¬ nate parts—the Black Rock (bed) “lode;” which—by aid of a steam-engine — set up at the bottom of the Great open-cast —is still mined some sixty-five fathoms below the surface. The North Discovery “ lode ” is worked to a depth of about one hundred and twelve fathoms. The richer ore was dressed in the ordinary manner; d the poorer was broken to about the size of eggs, and burnt. “ For which purpose it was placed between two parallel walls of vast length; some kilns were twenty, others forty, or fifty yards in length; some ten, others twenty feet wide, and above four feet in height. The space within was not only filled, but the ore was piled many feet higher, # # % the whole was then covered with flat stones, closely luted with clay * # Ht in order to prevent the fumes from escaping. The ore was set on fire by a very small quantity of coal, and it then burnt per se. The sulphureous particles passed off into long flues built of brick, where they subsided in form of the finest brimstone. Some of the [kilns] contained a Henwood, Cornwall Ocol. Trans., v, pp. 261,-3, Table LXIX. b Ibid, p. 232. c Hawkins, Ibid, iii. p. 287. d Pryce, Mineralogia Cornubiensis, pp. 233—43. Henwood, Cornwall Geol. Trans., iv. pp. 159—65. Henderson, Proceedings of the Institution of Civil Engineers, xvii. pp. 16—20. Copper-Mines in Ireland 579 From to but from to 1856 } therefore > 72-50 tons 1857 ) 54*25 1861 } ” M ” of precipitate were obtained, and the proportion of copper—ranging from 0*1500 to 0*6537—averaged 0*4634 its weight; of precipitate were obtained, and the proportion of copper—ranging from 0*2525 to 0*6125—averaged 0*4207 only; four hundred tons of ore, others two thousand; the first required four months to be completely burnt; the last near ten.”« The results of these operations—which have been discontinued here since 1862—were identical with those obtained at Agordo in the Venetian Alps; & that is to say:— “ ls£ stage —When a lump of ore in this stage is broken across, it is seen to consist of a central mass of unchanged ore, enclosed, as it were, in a rind or shell of a reddish-brown substance like sesquioxide of iron; and between the two is interposed a thin more or less continuous layer, which differs in lustre from, and contains more copper than, the original ore, and in appearance re¬ sembles copper-pyrites. % % % “ 2nd stage. —This stage occurs at about the middle of the roasting process. The external appearance of the ore is the same as in the first stage, but the weight is much diminished. On breaking the lump across, several concentric layers may be observed. In the centre is a nucleus of unchanged ore, surrounded first with a layer similar in appearance to copper-pyrites ; secondly, with a layer having a greater lustre and of a purplish colour, similar in appearance to purple copper-ore; thirdly here and there, with a layer having a metallic lustre and varying from the colour of indigo copper-ore to that of vitreous copper; lastly with a thick red-brown crust, forming the outer shell. % * # “ 3rd stage. —On breaking across a lump of ore in this stage, which occurs when the roasting is nearly completed, a nucleus of unchanged ore can no longer be seen; but within the now greatly increased outer red-brown crust some yellow, reddish, and bluish particles may yet be perceived. # & * “ 4 tli stage. —In this, the final stage, on breaking across a lump of ore it is found to consist only of a central nucleus having the appearance of vitreous copper or rather rich copper regulus, and an outer red-brown shell, not usually presenting any indication of concentric arrangement. # * * “ The kernels are separated by a few gentle blows with a hammer # * # and smelted for copper.” a Pennant, Tours in Wales, iii. pp. 61—3, 438—9, PI. XL1VJournal des Mines, No. xvi. (1795) p.70. Frere-Jean, Annales des Mines, xiii. p. 234—5. •• •• •• b Percy, Metallurgy, i. (Lurzer, Berg. u. huttenmannisches Jahrbuch, Tanner, 1853, 3, p. 339; & 1854, 4, p. 242) pp. 439,—44,—45. Haton, Annales des Mines, 5me Serie, viii. pp. 426-34. MMMM 580 W. J. Henwood, on the total yield having been 126*75 tons of precipitate, The rain-water—which occasionally percolates through this burnt rubbish— still bears with it to the precipitation-pits, notable quantities of the sulphate of copper.« The waters which, for a century, have given,& and still continue to give,® such ample precipitates, aforetime—like the stream at Dol-y-frwynog in Merioneth ^ —deposited their riches in the turf,& through which they rose to the surfaced The Parys and Mona mines now drain the surface so thoroughly, that—for want of fresh condensing-water—four, of their five, steam-engines are of high- pressure. (1.) “ The Parys mine emits annually about seven-hundred-million gallons of water impregnated with copper. This is collected in pits, into which is put old iron, which precipitates the copper. The average product of copper is from 55 to 60 tons ; and the iron consumed in obtaining this is 600 tons. The copper found in these waters, as indicated from the precipitate obtained, varies from 4 to 30 per cent., according to the wetness of the season; the sample I procured was during the dry season, and consequently rich in copper ; its specific gravity was TO 55 at 60° F. The solid contents of one gallon weighed 4,960 grains, which gave peroxide of iron 1,680 grains, oxide of copper 80 grains, sulphuric acid 3,040 grains, muriatic acid 38 grains, and 122 grains of earthy matters, which were not examined. In order to ascertain whether the copper might be extracted more cheaply by means of a galvanic current, or what is known as the electrotype process, than by the ordinary means of precipitation, a piece of iron, wrapped in a strip of brown paper, was attached to a piece of copper, and both were immersed in a solution of copper ore, in the muriatic acid, to be examined. The first action which took place, however, was the complete reduction of the persalt of iron to the state of protosalt, at the expense of the copper pole : after which the electric current began to effect its object, the copper being deposited, but from the copper which had been dissolved having also to be [precipitated], the consumption of iron was 658 grains, whilst the actual increase in weight of the copper pole was only 64 grains, the quantity of copper originally held in solution. # # # Different arrangements of batteries were tried; platinum, silver and lead were also sub¬ stituted for the copper, but in no case was a deposit obtained from the water until the iron was first brought into a state of protosalt; but when this was effected, a Thomas Fanning Evans, Esq., of Mona Lodge, Amlwch, Superintendent of the Mona Mine and Smelting Works, MSS. b Ante, p. 579, Note a. c Postea, pp. 581—4, Table XVIII. a d Henwood, Reports of the Royal Institution of Cornwall, xxxviii. (1856), p. 41. Ramsay, Memoirs of the Geological Survey of Great Britain, iii. p. 45. e In the neighbourhood of Dolgelley it is believed that the presence of copper in the soil, is indicated by the growth of the sea-pink or Thrift (Statice ArmeriaJ, which flourishes in such spots with remarkable luxuriance. Copper-Mines in Ireland 56 1 and the proportion of copper during the period* I obtained, by the method described 63 grains of copper by the loss of 53 grains of Iron. % % # “ Both zinc and iron, when put into the persalts of iron, first reduce the per- salt to the protosalt, which fully accounts for the great consumption of iron for the small [proportion] of copper obtained from these waste waters of mines, and not, as was generally supposed, from the existence of free acid; the copper is never all precipitated from the water so long as persalts of iron exist in the solution.” Napier, Lond. Edin. § Dublin Phil. Mag. xxiv. pp. 365—70 (abridged). The following columns show the quantities of Iron consumed and Precipitate obtained, the respective proportions of the Precipitate and of the Fine Copper to the Iron consumed, and of the Fine Copper to the Precipitate, at the Parys mines, during the years 1862—6. Quantities of Proportions of r Iron in use. Tons (Aw.) Iron Precipitate r Precipitate Fine Copper Years. consumed. Tons [Av.) obtained. Tons (Aw.) to Iron consumed. to Iron consumed. Y to Precipitate. 1862. a o •r-t O £ 05 568 363-8875 0-6406 0-1425 0 0911 1863. 2 a hH O %-t 599 327-2500 0-5463 0-1325 0 0723 1864. 611 296-7375 0-4857 0-1325 0-0644 1865. § Sg 418 284-8875 JO-6887 0-1112 0-0766 1866. rH ' g 35 550 27M250 0-4929 •0-1425 0-0702 Totals. — 2,746 1,546-8875 — — — Means. — — — 0-5633 0-1326 0-0746 Mr. James Williams, Accountant at the Mines, MSS. (2.) At the Mona mine— the copper-ores calcined from the beginning of 1832 } to an early part of 1862 amounted to.$ 155,404 tons (Avoir .); but since that time they have been differently treated;— the iron in use—reckoned annually—between 1832 and \ 1866, was, in the aggregate...5 of this the (light-iron) worn-out utensils whether of iron or tin-plate, and small scraps, indifferently of wrought or cast metal .... weighed 96,896 ,, 61,973 „ and the (heavy-iron) broken machinery f and other heavy junks of either kind .. 5 34,923 y> y )) y )) y 582 W. J. Henwood, on ranging from 0*1500 to 0 6537—having averaged, during the ten years, 0*4452 its weight. the quantity of iron consumed during the same period. of which the light-iron ...... ,, heavy-iron . the precipitate collected .... the fine copper obtained ... . weighed 30,386 tons (Avoir .); ,, 24,087 )) >> > >> 6,299 ,, >> } » 30,735 ,, ,i J » 2,977 )i jf • The following columns show the proportions of ore, iron, and copper, treated, consumed, and obtained, at various times and under different circumstances; a but Table XVIII. a mentions them in greater detail. Proportions _ of Precipitate of Fine Copper Periods. of Iron consumed. r to Iron in use. to Iron consumed. to Iron in use. to Iron consumed. to Precipi¬ tate. 1832—36. 0-3228 0-3383 1-0482 0-0338 0*1048 0*0999 1837—41. 0-2978 0 3653 1-2267 0-0374 0*1256 0*1024 1842—46. 0*2341 0 2472 1*0560 0*0288 0*1230 0*1164 1847—52 b . 0*3196 0-3102 0-9703 0-0346 0*1082 0*1115 1853—57 b ...... 0-3135 0*3414 1-0951 0*0239 0*0763 0*0697 1860—66 b . 0*3990 0 3207 0-8036 0-0281 6*0704 0-0876 First fifteen years .. 0*2794 0-3092 1*1065 0*0328 0*1175 0*1067 Last sixteen years b . 0*3379 0*3251 0-9620 0 0290 0*0858 0*0892 C Highest. Extremes < 0*5048 0*4931 1*8803 0*0558 0*2072 0*1373 C Lowest . 0*1715 0-2233 0*6505 0*0173 0*0549 0*0582 Means ... 0*3136 0*3175 1-0239 0-0308 0*0993 0*0969 a The annual fall of rain at the Mona mine has been in 1861 .... 44’45 inches; 2 .... 40-14 „ 3 .... 40-83 „ 1864 .... 33-89 inches; 5 .... 44-17 „ ; 6 .... 42-23 „ . Thomas Fanning Evans, Esq., MSS. b The Returns for 1850,—7,—8, & —62 are incomplete. Years in which Copper-Mines in Ireland . 583 The broken machinery and worn-out tools used the weight of iron in use exceeded an average.. fell short of >» the proportion of iron consumed exceeded an average.. fell short of 4 the proportion of precipitate to iron in use exceeded an average.. fell short of „ the proportion of precipitate to iron consumed exceeded an average.. fell short of ,, the proportion of fine copper to iron in use exceeded an average.. fell short of >» the proportion of fine copper to iron consumed exceeded an average.. fell short of ,, .. the proportion of fine copper to precipitate exceeded an average., fell short of „ Proportions _a- of Iron consumed. of Precipitate of Fine Copper. to iron in use. to Iron consumed. to Iron in use. to Iron consumed. A to Precipi tate. 0-2923 0-2975 • • • • . • • 0-0289 0-0973 0*3517 0-3545 0 0342 0-0966 0-3783 0-9106 0-0874 0 0960 0-2529 1-1004 0-1084 0-0985 0*3291 0-3841 0-0343 0 0894 0*2958 0-2673 0-0280 01050 0-2649 0*3765 0-1326 0-0964 0-3428 0-8842 0 0863 0 0976 0*3153 0*3722 0 0340 0-1073 0*3074 0-2817 0-0247 0-0877 0-2671 1-1585 0-1279 0-1104 0-3570 0-9157 0-0762 0-0832 0-3082 0-1114 0-3357 0 0763 Of the ochre, which is continually formed, 17,833*06 tons (Avoir,) have been prepared for sale since 1860; namely— 584 W. J. Hen wood, on in the precipitation works, comprise a much larger 1861 2 3 4 2,567-06 tons, 2,061-92 ,, , 2,232-81 „ , 2,492-30 „ , 1865 . 6 ...... 7 . beside great quantities which escaped to the sea. 2,016 98 tons, 3,175-84 „ , 3,286-15 „ , “ The water from different parts of the mine, contains unequal proportions of, more than one, metallic salt; as the works are extended, indeed, they open at times springs of various qualities; generally speaking, however, the streams issuing from the great metalliferous deposit and from the quartzose rocks on the S., are more highly charged with the sulphates of iron and copper, than those flowing from the less siliceous slates, and from the smaller productive (beds) ‘ lodes ’ which interlie them towards the N. Soon after the wet season sets in, the mine-water becomes more abundant, and the precipitate—increasing in some proportion to the rain—is, at the same time, both larger and richer than during any other period of the year. The proportion of solid matter contained in this water, as it flowed from the pump in February 1868, w-as about (0 0304 its weight) thirteen thousand four hundred and thirty-eight grains to the cubic foot. “ As precipitation takes place more slowly in cold, than in warm, weather; all mine-water is retained in tanks, and the works are suspended, during frost.” Thomas Fanning Evans, Esq., MSS. (3.) At the Devonshire Great Consolidated Copper Mines a the water contains generally less than thirteen grains (about 0-00003 its weight) of copper to the cubic foot; a quantity too small to repay the cost of extraction. The streams which enter the shallower levels near the Wheal Josiah and the Wheal Maria shafts, are, however, more highly charged; but that of the former is—on its way to the surface—mixed with the less richly impregnated water from the deeper works. The following columns comprise both the elements and the results of the precipitation carried on, at these respective parts of the mines in 1866. Copper, grains of per cubic foot of water ... ,, precipitate, obtained, tons . „ fine, contained in the precipitate, tons Iron in use, constantly maintained at, ,, ,, consumed.*.. ,, Iron consumed .... to iron in use . Precipitate obtained ,, . Fine copper in precipitate „ .. . Precipitate obtained to iron consumed . Fine copper in precipitate ,, . Fine copper in precipitate . Wheal Josiah. Wheal Maria. QUANTITIES. 29-15 • • • • 48-02 17-00 • • • • 12-00 7-90 • • • • 6-00 36-00 • • • • 19-00 30-80 • • • • 24-00 PROPORTIONS 0-4611 • • • • 0-5581 0-2545 • • • • 0-2791 0-1183 • • • • 0-1395 0-5519 • • t • 0-5000 0-2565 • • • • 0*2500 0*4647 • » • • 0-5000 a Ante, pp. 457-8, Table XIV. Copper-Mines in Ireland . 585 proportion of cast, than of wrought, iron ; blit especial The quantity of water is smaller, but it contains a larger proportion of cop per, in summer than in winter. The iron is frequently dissolved by water which deposits no copper.® Extracts from, Official Records , by Mr. Isaac Richards, Accountant at the Mines. (4.) At Wheal Agar —an abandoned mine near Crow’s-nest in the Caradon district & —copper has been deposited for some years, by the adit- water in which the (Alga) Mougeotia thrives, even whilst it adheres to the precipitated metal. The precipitate obtained is about 0*7500 the weight of the iron consumed, ( 0*2250 | the fine copper „ from ) to > ( 0 2625 ) ” j 0*3000 1 „ ,, from ) t0 f „ the precipitate. I 0*3500 ) ” (5.) “ About sixty years ago [the precipitation of copper by iron] was first observed by Mr. Coster in Chacewater Mine near Redruth; for after he had drawn out the water, which had been in the mine for several years, he found the poll of a pick-axe wholly encrusted with a case of malleable Copper between two and three pounds in weight. This it was justly supposed was observed by the workmen, some of whom afterwards settled at Cranbaun Mine in the county of Wicklow The water of Cranbaun having this vitriolic acid in a very high degree, Capt, Thomas Butler, who was one of Redruth, and manager of that mine, persuaded the proprietors to adopt the scheme of precipitating copper, of which they have made for many years past and now continue to make very con- considerable profit.”— Pryce, Mineralogia Cornubiensis (1778), p. 231. About 1830, some small parcels of copper, precipitated from the mine-water with lime at Wheal Falmouth , realized at the ticketting from £8 to £9 per ton, James Treweek, Esq., of Chatham Lodge, sometime Manager of Wheal Falmouth , MSS. (7.) The Great (Gwennap) adit extends its several branches in different directions between thirty and forty miles, through the most productive copper- district in Cornwall; c draining an area of five thousand five hundred and fifty acres; and discharging—after the drought of summer less than nine hundred, —after the rains of winter nearly two thousand nine hundred,—and on an aver¬ age about fourteen hundred and fifty, cubic feet of water per minute. 0 This a Ante, p. 580. b Postea, pp. 620—30. c Thomas, Deport on the Mining District from Chaservater to Camborne, p. 28; History of Falmouth, p. 33. Henwood, Phil. Mag. § Annals, ix. (1831) p. 170, Cornwall Geol. Trans., v. pp. 89*, 422—6. 586 W. J. Henwood, on account was not taken of the quantities. It is believed, however, that the precipitate obtained was about (four-fifths) 0*8000 the weight of the iron consumed; in which case the copper must have been ,, . 0*3562 ,, ,, stream has, at different times, varied in temperature from 60°*5 « to 69°*25.& In August, 1867, a cubic foot yielded, on evaporation, seven hundred and thirty- five grains of residuum, which, for the most part, consisted of c Iron. Sulphuric acid. Calcium. Hydrochloric acid. Sodium. with traces of other substances.^ It is a remarkable—and perhaps a characteristic—circumstance, that notwith¬ standing the Great Adit had been extended to the western boundary of Poldice, as early as 1768, by Mr. Williams; e and that, in the interval, a side-drift from it had been opened to the very ( Chacewaterf mine in which the precipitation of copper by iron had been observed about 1728/ by Mr. Coster; no successful —if indeed any—attempt was made, to extract the water contained in the adit- water which had for so many years passed into the sea at Restronguet until late in the present century. In 1854, however, Mr. Richard Symons, of Twelve- Heads,—-who had gained some experience in the mines of Cuba,—opened pre¬ cipitation-pits on the stream, and the success of his operations stimulated his neighbours; in the course of eight or ten years, therefore, at least a dozen other parties had established themselves, on its banks, between Bissoe and Tarnon Dean, villages a mile and a quarter apart. As each of these is indepen¬ dent of every other, and as many of the partners in all are themselves the a Henwood, Cornwall Qeol. Trans., v, p. 411. b Fox. Ibid , iii. p. 316. c Qualitative analysis by Mr. John Edgar Wright, A.A., of Penzance. d One of the Wheal Clifford tributaries—which issued from the lode at a temperature of 125°—afforded per cubic foot of water, the undermentioned quantities of saline matter; namely— Chloride of Lithium. 1595*6 grains; „ Potassium with a little Chloride of Caesium . . 90*90 „ „ Sodium . 2,227*11 „ „ Magnesium . 54-27 „ „ Calcium...,. 1,324*04 „ Sulphate of Calcium ..... 75*15 „ Silica . 22*35 „ Oxides of Iron, Aluminum, and Magnesium ... in minute quantities. 3,953*38 grains. Miller, Report of the British Association for 1864, Part ii. p. 36. e Henwood, Cornwall Qeol. Trans., v. p. 89*. /Pryce, Mincralogia Cornubiensis, p. 231. Ante, p. 285. Copper-Mines in Ireland. The following comparisons 587 Proportion of _A_ Precipitate to r Fine Copper to _A_ Mines and periods. Rock. Iron consumed Iron in use. Iron consumed. Iron consumed. Precipi¬ tate. Precipitate to Water. Connorree, C 1838 9.. 0-3226 0-3216 0-9969 0-00020000 ( 1861_2^ Clay-slate. 0-4800 0-2100 0-1400 0-4400 0-3500 Cronebane, 1862 .... Clay-slate. - 0-4000 Ballymurtagh, C 1852—6.. X 1857—61. Clay-slate. ~ -1 0-8000 0-3562^ 0-4634 0-4207 — workmen; it has been found impossible to obtain full particulars of their operations. In each series of (strips) pits the iron in use is commonly maintained at. 4 or 5 tons, and by the consumption of... from 2 to „ a precipitate of. about.... 1 ton is obtained.® The precipitate collected, has, for some time past, ranged from eighty to one hundred, and averaged about ninety, tons a year.& The proportions of fine copper it has afforded at different times are shown in the following columns:— Years. Highest Lowest. Average. 1864 . 0-6162 0-1500 0-3329 5. 0-5875 0-1200 0-4054 6. 0-5875 0-1200 0-3703 7. 0-6150 0 0625 0-4037 Extremes .... 0-6162 0 0625 _ Mean. — — 0-3900 Howard Bankart, Esq., Managing Partner of the Red Jacket Copper Works, Briton Ferry, South Wales, MSS. a Mr. John Ninnessof Twelve-Heads; a Proprietor of Precipitation-works. 6 Henry Williams, Esq., of Alma near Truro, Sampler and Shipping Agent of Messrs. Vivian. NNNN 588 W. J. Henwood, on show that the water now yields smaller proportions of copper than it formerly yielded. The proportions of the results obtained are,— to Iron in use. to Iron consumed. to Precipitate. Iron consumed .... 0*4000—0*6250 Precipitate. 0*2000—0*2500 0*4000—0*5000 Fine Copper . 0*0125—0*1540 0*0250—0*3081 0*3900 Taking, therefore,— the average discharge of the adit«. ,, quantity of saline matter contained in the water &. at 1,450 cubic feet per minute ; ,, 735 grains per cubic foot; 99 19 „ precipitate obtained c .. proportion of fine copper contained ? in the precipitate ” 90 tons per annum; 0*390 its weight; the salts amount to. about 0*001220 the weight of the water; ,, precipitate amounts to. ,, 0*00000423 „ „ ; „ fine copper „ . ,, 0 00000165 ,, ,, ; that is to say, 423 parts of precipitate j are extracted from 100,000,000* parts containing 165 „ fine copper ) 0 f wa t e r. or (three thousand seven ) hundred and eighty- > one hundred and five tons of water yield about one pound of pre- four cubic feet) ) cipitate; „ (nine thousand six'! hundred and ninety- > two hundred Sc seventy „ „ ,, „ of fine three cubic feet) copper. The foregoing approximations—although as close, perhaps, as our present means of information permit—make no pretension to minute accuracy; they show, however, the remarkable means by which many industrious families earn a comfortable livelihood. The precipitate is both richer and more abundant, in winter than in summer; and at all seasons it is of better quality in the upper, than in the lower, part of the stream. When tinned iron is used as a precipitant, the deposit obtained affords metal of much the same kind as that smelted from tinny copper-ore. In this water,—as in that of Wheal Agar , d —the (Alga) Mougeotia flourishes. Although the several tributaries of the adit rise in the Parishes of Redruth, Kenwyn, and Gwennap, the owners of land abutting on lower parts of its stream, in Kea, Feock, and Perran-ar-worthal, claim (Royalty) Dues —in two or three cases of one-tenth, but generally of one-fifteenth—of all precipitate collected in pits opened on their respective freeholds. (8.) “ The water issuing from the adit at Tresavean, often yields a copious a Thomas, Cornwall Oeol. Trans-, v. p. 422. Henwood, Ibid, p. 423. Ante, p. 586. b Ante, p. 58G. c Ante, p. 587, Note b. d Ante, p. 585. Copper-Mines in Ireland , 589 At Ballygahan precipitation has long been dis¬ continued. precipitate ; though sometimes it dissolves the iron immersed in it, yet deposits but little copper instead.® The precipitate contains from O'10 to 0*30 its weight of pure metal.” Captain Thomas Blamey, of Lanner near Redruth, MSS. (9.) “ Experiments have been made lately on the water which flows from the adits of Dolcoath, Cook' s-kitchen, Wheal Croftyfi and North Roskear,c but with little success; nor, in fact, has any copper, worth notice, been observed in the calcareous sand d through which it escapes into the sea at Gwithian.” William Cock Vivian, Esq., of North Roskear , MSS. (10.) “ The following description of the process of cementation applies gene¬ rally to the mines of the province of Huelva. e The ore is first calcined, in heaps, varying in dimensions; a common measurement for the base of the truncated pyramid is 12 metres by 7 metres [39’3 by 23*0 feet]; the usual height is about 1 metre [nearly 3 - 3 feet] ; such a heap contains about 4,000 quintals [181 tons Avoir.). The cost of calcination * * * , labour and fuel included, was, in 1859, 36 cents per quintal of ore, equal, to Is. 7 \d. per ton. The time required to complete the operation is from five to six months. The heaps are open to the air, and have no covering of any sort. % # % The ore is said to lose about 20 per cent, of its weight in the operation of calcination. “ The calcined mineral is [conveyed] to the lixivation tanks, [which] are gene¬ rally constructed of rough masonry, and lined with asphalte; their dimensions vary considerably, but the most common size is 7 metres long by wide and 1 deep [23'0 X 14*2 X 3*3 feet]. They are two-thirds filled with ore, and con¬ tain about 2,000 arrobas, say 23 tons nearly. The length of time the ore is allowed to remain in the tanks varies in different establishments; it depends on the quality of the ore, and the greater or less perfection of the calcination. At Rio Tinto from seven to nine days usually suffice, but at La Chaparita twelve days [are sometimes required]. The waters are drawn off and renewed as often as necessary; the first water is saturated in two or three hours, the last is left as many days. “ From the lixivation tanks the water, charged with salts of iron and copper, passes to those of cementation ; the latter being of nearly the same form and dimensions as the former. In them are placed pieces of pig iron forming squares. “ During winter it is found necessary to agitate the water to accelerate the precipitation of the copper, but during the hot season this is not much practised. a Napier, London, Edin., 4* Dublin Phil. Mag., xxiv. pp. 365,—70. Ante, pp. 580—1. b Pryce, Mineralogia Cornubiensis, p. 232. c Thomas, Ante, p. 354, Note } d Henwood (Pepper’s Play-book of the Metals), p. 275. e Ante, pp. 543—6, 590 W. J. Henwood, on The vale of Ovoca was long celebrated for the When the solution has been sufficiently impoverished it is drawn off into a third tank, and left to deposit the subsalts of iron held in suspension; the resulting precipitate is found to contain 10 per cent, of copper and a good deal of arsenic. After the solution has been drawn off from the cementation tanks, the pigs of iron are freed from the copper adhering to them, and the precipitate is collected. This assays about 55 per cent, for copper, and varies from 50 to 60 per cent. “ The iron consumed in cementing at the Rio Tinto mines for the year 1859 was 2-17 to 1 of copper. “ The quintal of calcined mineral costs for expenses of lixivation and ce¬ mentation 1 real 72 c. or 4 ~d. nearly.” [7s. 9f d. per ton Avoir.] Thomas, Notes on the Mines of Rio Tinto , pp. 14—16; Mining and Smelting Magazine, I. p. 116. (11.) “ At the Lucen$ia mines, near Yalverde in the same Province, the mine- water is passed through heaps of calcined ore on its way to the pits; in which a precipitate, containing from 50 to 60 per cent, of copper, is obtained by the con¬ sumption of four or five times its weight of pig-iron.” The precipitate is, therefore, from 0-20 to 0*25 the weight of the iron consumed; ,, fine copper „ „ 0T0 „ 0-15 „ „ „ ; ,, „ „ ,, 0-50 ,, 0-60 ,, precipitate obtained. Frederick. Bankart, Esq., of Langley Lodge, Herts, MSS. (12.) Precipitation—established in Cuba by me during 1844—was carried on at the Santiago « mines in a series of tanks and launders. \ Each of the first three tanks was 12 feet long, 6 feet wide, and 6 feet deep; ,, second three ,, ,, 12 ,, ,, , 6 ,, ,, , and 4 ,, ,, . As the surface had but a slight slope, each tank was divided crosswise to within a foot of the bottom, in order that the water might descend on one side of the partition, ascend on the other; and, at length, pass off through launders , about two feet in width, and a foot in depth. In each compartment of every tank three or four wooden racks were laid with wrought iron bars, and the launders were supplied with scraps of iron. The weight, of both sorts, in use was maintained at about one hundred tons. The water—in time of drought as little as ten,—during rain as much as one hundred and fifty,—and on an average perhaps (3-2653 cubic feet) twenty, gallons per minute—filtrated through heaps of (halvans) inferior ore, the refuse of several previous years, on its way to the tanks. Bar-iron, direct from the Manufacturer, ^ extracted from water of good * about 1-2000 its weight of precipitate; strength .. „ of like quality, threw down, from water of less strength, but small scrap, and rusty, iron, sepa¬ rated from weaker solutions. ,, its own weight „ 0-7770 a Ansted, Journal of the Oeol. Soc., xii. pp. 144—53. Ante, p. 441, Table XIV. Copper-Mines in Ireland. 591 variety and beauty of its scenery; but the railway The precipitate contained in but a single instance less than 0-7000 its weight of fine copper; „ „ in another case as much as .... 0*8950 „ , „ ,, on an average ... 0 7500 ,, The mean monthly returns of precipitate were about five tons. James Treweek, Esq , sometime Superintendent of the Royal Santiago Mines, MSS. Now if the quantity of water amounted to (20 gallons) 3*2653 cubic feet per minute,— ,, precipitate „ . 5* tons per month,— and the precipitate yielded . 0-7500 its weight of fine copper; the water must have afforded 0*00125297 its weight of precipitate, & „ „ 0*00093973 „ fine copper. One pound of precipitate was, therefore, obtained J (12| cubic fflet) 798 lbs> (0 . 8fl ton) of water . „ fine copper „ „ (17 „ ) 1,064 „ (0*47 „ ) „ ; this water must consequently have been more than five hundred times as rich in copper as the stream of the Great (Gwennap) Adit is at present.® (13.) “ When the Cobreb mines were in full work, they afforded from sixteen to eighteen tons of rich precipitate per month for many years. * % * But since underground operations have been confined (almost exclusively) to the deep levels , where the ore consists altogether of hard compact copper pyrites, the quantity of precipitate obtained has been much reduced; and, with the present diminished scale of operations, it probably does not exceed five or six tons per month, whilst the quality is very inferior.”— John Petherick, Esq., F.G.S., Consulting Engineer of The Cobre Mining Company, MSS. During 1854,— 5,— 6, and 1864,— 5,— 6, respectively, the undermentioned quantities and qualities of precipitated copper from the Cobre mine, were sold at Swansea:— Quantity of Precipitate. Tons [Avoir.) Proportion of Fine Copper in Precipitate. Years r Highest. Lowest. ' ' A Mean. 1854 . 244 0-7737 0-6100 0-6891 5 . 235 0-7462 0-4500 0-6745 6 . 193 0-7700 0-5300 0-6504 Total ... 672 — — —— Extremes . — 0-7737 0-4500 — Mes n ...... r - - 0-6736 1864 . 180 0*7225 0-3500 0*6298 5 163 0-7100 0-4750 0*5628 6 . 278 07500 0-3750 0-6300 621 mm ^ mm > Extremes . 0-7500 0-3500 0-6123 John Williams, Esq , Agent at Swansea for The Governor and Company of Copper Miners, MSS. a Ante, p. 588. b Ante, p. 441, Table XIV. 592 W. J. Hen wood, on and mine-works have destroyed much of its surface and poisoned most of its water. Copper-Mines in Ireland. 593 The Knockmahon Mine, immediately E. of Bonma- hon, in the county of Waterford,* has been wrought both inland and beneath the sea in rocks of the Silurian system, on several lodes. (a.) The metalliferous slates range nearly N.E.— S.W.; and dip towards the S.E, at various—but always at low—angles. Their cleavage—though sometimes regular—is mostly uneven ; and—whilst occasionally flecked with some pearl-white substance—they are generally homogeneous, In S.E. and central parts of the mine, their prevailing tints vary, from greenish and bluish black to greyish green; but towards the N.W. they are of coal-black hue.f Massive rocks of * “ Tradition tells of ore having been raised from Knockmahon in the reign of Elizabeth and at other periods down to 1730, when a Mr. Hume worked profitably the Stage lode for a length of time. In 1796, and some years sub¬ sequently, Colonel Hall and Mr. Galway spent a large sum on various parts of the ground unsuccessfully. It then passed into the hands of the Hibernian Mining Company, and in 1824 became the property of the Mining Company of Ireland, who have prosecuted the workings continuously to the present time [1863] with varying success; * * * . “ Seven steam-engines and six water-wheels assist in the general operations, # $ * The water-power is principally derived from the River Mahon, being brought to the dressing-floors by an artificial cut three miles in length; % * *. “ The ore is shipped off to Liverpool and Swansea by vessels that (weather permitting) come close in shore; there being no harbour nearer than Dungarvan or Waterford.” Hore, Explanation to accompany Sheets 167, 168, 178, and 179 of the Maps and Section 13 of the Geological Survey of Ireland , p. 81. f “ The eastern portion of the county of Waterford consists almost entirely of clay slate. * * * In the vicinity of Bonmaghon, copper mines were formerly worked to some extent.”— Weaver, Geol. Trans, v. p. 248. “ In the extreme S.W. corner of the townland of Tankardstown, % * * we enter on a mass of gray slates interstratified with some beds of greenish-gray feldspathic ash, which are traversed from N.W. to S.E., or across their general strike, by five of the most productive of the Knockmahon copper lodes. % % * This brings us into the townland of Knockmahon, the western portion of which is formed of alternate bands of pale greenish-gray felstone, hard gray ash 594 W. J. Henwood, on felspar and quartz are exposed in several of the works; and a well-defined bed of felspar and hornblende approaches the black slate near the Mahon. (&.) Several of the lodes and many of their branches crop out in the cliff; # and some of them are worked beneath the sea. Fig. 31. KNOCKMAHON MINE, COUNTY OF "WATERFORD. Longitudinal section of the Stage lode. Scale 40 fathoms to the inch. a. Level of high-water at half-spring. b. ,, low-water ,, c c c. Artificial dams , built to prevent irruptions of the sea through openings accidentally made from below. (sometimes containing thin layers formed of broken-up fragments of trilobites, encrinites, and small cup corals), and earthy gray slate, forming a portion of the same series of rocks just noticed and traversed like them from N.W. to S.E. across their strike by the Old Stage Lode and its numerous branches, and at the western extremity of the townland by four minor lodes. In the extreme N.W. corner of the townland we find a thin dyke of greenstone overlaid by a felspathic ash and a layer of purplish brown grit dipping to the S.E. at 20°.” Du Noyer, Explanations to accompany Sheets 167, &c., of the Geological Survey of Ireland , p. 57. * “ The Tankardstown lode, the most eastward of all the lodes at Knockmahon, Copper-Mines in Ireland. 595 Their directions and dips are much the same as those * * * strikes N.W. for half a mile from the coast, when it strikes to the N.N. W., and has been worked at detached localities for a further distance of half a mile. It inclines to the S.W. at angles varying from the horizon from 52° to 68°. Sea¬ wards, this lode has been profitably worked for the distance of 250 yards from the shore. “ Rowe’s lode appears in the cliff at the distance of 60 yards to the west of Tankardstown lode, which it joins inland at the distance of 125 yards. It occurs on the line of a fault, and strikes N. & S, with an inclination of 70° to the west. At the junction of these two lodes the solid copper-bearing lode was nearly 70 feet in width, decreasing, however, rapidly to 4 feet as it was followed on the strike of the greater lode. “ Boneyaughl lode [which succeeds Rowe’s] has been traced along a line of fault in a direction of N. 10° to 15° W. for the distance of half a mile from the coast, with an inclination of 50° to the eastward, but it has not been worked beneath the sea. “ Sixty yards [from] Boneyaught’lode is the Kilduane lode, the general strike of which is N.N.W. from the coast with an inclination of 50° to the eastward: it, or a lode resembling it, has been followed inland for about a mile. “ A hundred yards to the west of this lode is the Seven Dials lode, which has much the same strike and inclination. “ All these lodes occur in gray slate as well as in the feldstone, crossing the bedding at right angles. “ At the distance of 350 yards west of the Seven Dials lode is the Old Stage lode, with its numerous branches and strings, discovered close to the coast. # % Ht The strike of the Stage lode is about N.W., the “ hade ” being vari¬ able, but generally vertical. When the “ red ground (the red conglomerate and shale in the Silurian rocks) was reached under the crushing floors of the mine the lode was lost, but it is supposed that to the north of these beds, under the name of the North Mine lode, it was recovered, and it has been worked for over three-quarters of a mile through the porphyritic feldstone into the townland of Ballynasissla. Here the lode was again lost where the black slaty band on the north was reached, but by furtheroperations in the neighbourhood these black slates were found to contain copper in workable quantities, disseminated throughout them in strings, and filling up small cracks and fissures.” Du Noyer, Explanations to accompany Sheets 167, &c., of the Geological Survey of Ireland, pp. 81—2. (Abridged.) ** A remarkable fossiliferous locality occurs on the shore, close under the engine-house of the Knockmahon copper mines, which Mr. Du Noyer describes as an “ ash bed: ” it is a hard bluish gray rock, characterized by bands of the variety of Stenopora fibrosa , called ly coper don, which stand out from the rock where exposed to the sea action like nodular concretions, until on a closer ex¬ amination they are found to be corals. * % ^4 The fine Brachiopod Orthis crispa, so frequently occurring throughout this district, is also plentiful here: an uncommon Gasteropod shell Raphistoma elliptica ; and the Trilobites Phacops Brongniarti and Asaphus gigas have also been collected at this place.” Baily, Ibid, p. 24. 0000 596 W. J. Henwood, on maintained by the lodes of the St. Just district,* by the Gaunter lodes of West Corn wall, f and by some of the lodes in Bearhaven .J The following columns afford comparisons of the directions and dips of the North Mine and Stage lodes with the direction and dip of the rocks; as well as of the dimensions of one lode, to a depth of forty-six fathoms, with those of the other from sixty-six to ninety-six fathoms from the surface.^ Lodes and Rocks. Directions. Dips. Depths: fms. Sizes: feet. North Mine Lode . 38°—45° W. of N.—E. of S. N.E. 20°— 70°. Surface to 46 8—30 Stage Lode .. Cleavage of the slates ||.. / 38°—45° W. of N.—E. of S. N.E.—S.W. N.E. 60°— S.W. 60°. S.E. 10°— 40°. 66—96 1—15 1 Both the lodes contain many masses of slate, of various sizes, but, in composition, they are all identical with the rocks respectively adjoining. Some of them lie imbedded in clay; but by far the greater numbers are enveloped in, and transfused with, siliceous matter, * Carne, Cornwall Geol. Trans., n. p. 321. Henwood, Ibid, v. p. 250, Table cm. f Hitchins, Phil. Trans., xci. pp. 159—64. William Phillips, Geol. Trans., II. pp. 146—52. Thomas, Survey of the Mining District from Chasewater to Camborne, p. 19. Carne, Cornwall Geol. Trans., n. pp. 105, 321. Burr, Mining Review, No. vm. (1836) p. 210. Fox, Report of the Royal Cornwall Polytechnic Society, iv. p. 83. DelaBeche, Report on the Geology of Cornwall, &c., p. 365. Henwood, Edin. New Phil. Journal, xxii. p. 159; Cormoall Geol. Trans., v. p. 253. + Smyth, Explanation to accompany Sheets 191,197, § 198 of the Geological Survey of Ireland, p. 31. Postea, p. 611. § Table XIX. || DuNoyer, Explanations to accompany Sheets 167,168, 178, % 179 of the Geol. Survey of Ireland, p. 56. Copper-Mines in Ireland, 597 mixed with smaller proportions of chlorite and calca¬ reous spar ; whilst all are veined with quartz. Small quantities of earthy brown iron-ore occur near the surface, and iron-pyrites is common at greater depths. Malachite, earthy black, and vitreous, copper, and other rare ores of the same metal, are sparingly scat¬ tered through shallow parts of the matrix ; but in both lodes copper-pyrites prevails.* Longitudinal joints divide the lodes into subordi¬ nate (slices) veins ; some of which exhibit, at intervals, characteristic differences of composition. The masses (bunches) of ore—declining f from the great felspathic formation J on the N.W., N., and N.E., as the slates also decline; J yet conforming to * At the depth of 100 fathoms the Tankardstown lode presented a productive width 40 to 60 feet, and in some places more than this, all the stuff 1 yielding yellow copper ore of remarkable purity.”—D uNoyer, Explanations to accompany Sheets 167, 168, 178, § 179 of the Geological Survey of Ireland , p. 81. “ On one part of the Tankardstown lode three levels were driven abreast at the same time, through copper-pyrites; bodies of similar ore being, for a while, left standing between them.” Captain James Clemes, Manager of Knockmahon, MSS. f Henwood, Edin. New Phil, Journal , xxn. p. 157; Cornwall Geol. Trans., v. pp. 51, 54, 87*,129,—93. “ The quartziferous porphyry consists of small crystals of flesh-coloured fel¬ spar and quartz, embedded in a paste which I imagine to be essentially aluminous; with the aid of a powerful glass, minute cubes of iron pyrites are seen, which, with the felspar and quartz, are the only crystalline substances. This formation is rather extensive on the line of coast to the east of Bonmahon Bay, and is also found cropping out on the sides of several low ranges of hills, and even obtaining a considerable altitude in more than one place inland.” Holdsworth, Journal of thd Geological Society of Dublin , i. p. 88. Geological Survey of Ireland, Sheet 178. Du Noyer, Explanation to accompany Sheets 167, 168, 178, <$, 179 of the Geol. Survey of Ireland , pp. 56—9. t Weaver, Geol. Trans., v. pp. 140—185. Boase, Cornwall Geol. Trans., iv. p. 432; Treatise on Primary Geology, p. 119. 598 W. J. Henwood, on i the schistose structure of the neighbouring rocks, # — as in other localities the shoots , as well of similar as of different f ores also conform—dip endlong towards the S.E. (c.) The directions, dips, and sizes of the cross- (flucans) veins are Cross- (Jlucans) veins. Directions. Dips. Widths: feet. North Mine flucan .... 20°—25° E. of N.— W. of S. N.—N.W. 70°—76°. 1. Stage flucan . 40°—42° E. of N.— W. of S. S.E. 70°. o I CO • They consist, for the most part, of slaty clay and disintegrated felspar ; enclosing, however, many spheroidal masses of quartz.^ ( d .) The North Mine flucan — at 16 fins, deep is a single vein; .... which heaves the North Mine lode 46 fms,; „ 46 ,, ,, forms three distinct branches ; each of which leaves the same lode, the sum of their heaves amounting to .. 25 ,, . The Stage Mine lode —* * * § at 86 fms. deep intersects the Stage lode . and heaves it 4 feet; ,,96 ,, ,, intersects a branch of the same lode .... hut does not heave it. In both cases, however,—as in more than one-half the displacements of copper -lodes by cross-veins in Cornwall §—the heaves are to the Right-hand and to¬ wards the side of the Greater-Angle. (e.) Between twenty and thirty-six fathoms from the surface, a (Slide) vein of slaty clay scarcely an inch in * Tregaskis, Report of the Royal Cornwall Roly technic Society , iv. p. 95. Ante, p. 207. Postea, p. 613. t Henwood, Cornwall Geol. Trans., v. pp. 41, 24, 87, 129,—93; vi. p. 146; Ante, pp. 32, 207,—63,—4,—83, 382, 439, 535,—7,—78, Postea, p, 613, X Henwood, Cornwall Geol . Trans., v. p. 262, Note. § Ibid, pp. 286—7, Table CVII. Copper-Mines in Ireland. 599 width,—having nearly the same direction as the North Mine lode but an opposite dip,—occasions a (leap or throw) vertical displacement of about sixteen fathoms (upward) towards the side of the Greater-Angle.* On the Stage lode a rich hunch (shoot) of ore was followed in several levels —as it dipped endlong—to- towards the S.E.; not only beneath the beach,—of which a breadth of fifty fathoms is left dry at low- water,—but, beyond it, for at least one hundred fathoms under the sea. At the depth of one hundred and six fathoms, in fact, the works have been extended fully one hundred and fifty fathoms from the cliff, which, at half-spring tide is washed by the sea at high-water.')' For some time, however, the shallower works were * The interferences of copper -lodes with slides “ present either simple inter¬ sections, or leaps downwards towards the greater angle.” Henwood, Cornwall Geol. Trans., v. p. 332. f “ The shaft N. of the Old Stage was sunk 212 fathoms, and in driving on this lode, seawards, several runs took place from the works having been carried on too close to the sea floor, and at the distance of about 350 yards from the coast the sea broke into the mine some years since, and great difficulty was ex¬ perienced in staunching the break. The works on this lode have been carried on beneath the sea to the distance of about 500 yards from the coast line.” Du Noyer, Explanation to accompany Sheets 167, 168, 178 $ 179 of the Geological Survey of Ireland, p. 82. The undermentioned mines in West Cornwall are still wrought beneath the sea;— “ At Wheal Margery near St. Ives the 120-fathom level extends 121 fathoms from the shore.”— Captain Richard James, Manager of Wheal Margery, MSS. “ At Levant in St. Just the 150-fathom level has been driven 299 fathoms be¬ neath the sea.”— Captain J. Nicholas, Manager of Levant , MSS. “ At Botallack in St. Just the 115-fathom level extends 384 fathoms seawards from the base of the cliff.” Stephen Harvey James, Esq., Manager of Botallack , MSS. “ At Whitehaven certain seams of coal, remarkable for their thickness and regularity, are worked by Lord Lonsdale along a coast line of nearly 2 miles to the distance of 1| mile under the sea. Smyth, Treatise on Coal and Coal Mining, p. 50. 600 W. J. Henwood, on conducted so incautiously, and the crust of vein-stone left standing between them and the strand was so thin, that at eight fathoms from the cliff, in the back of the sixteen-fathom level , „ thirty „ „ „ twenty-six- „ „ the sea found its way into the mine, but,—with great difficulty and at a great expense—it was, in both places, successfully dammed out.* * “ In Little Bounds, Botallack, and Wheal Cock the ore was followed upward even to the sea; but the openings made were very small, and the rock being extremely hard, a covering of wood and cement in the two former, and a plug in the latter sufficed to exclude the water, and protected the workmen from the consequences of their rashness.”— Carne, Cornwall Geol. Trans., n. pp. 339, —41,—43. Henwood, Ibid, v. p. 10. “ At Workington the seams worked beneath the sea % % % were followed up too far, and as due precaution was strangely disregarded, the sea burst in in 1837, and the lamentable result was the loss of thirty-six human lives, and the entire destruction of the colliery.”— Smyth, Coal and Coal-Mining, p. 51. In April, 1840, the imprudent removal of a prop (stull) caused many thousand tons of rubbish to fall on Michael Walsh of Bonmahon, one of several miners engaged at the sixty-six fathom level, beneath the sea. Although little or no hope of his safety-remained, a strong party was instantly employed, as well to extricate the body that it might be decently buried, as to re-open the drift and repair the damage. After the men had worked some twenty-four hours, how¬ ever, they were astonished to hear the voice of their lost comrade, who was shut in by masses of the fallen rocks. He told them that his knees almost touched his chin,—that salt-water had risen nearly to his mouth,—and that he had eaten his last candle. Relays of the ablest workmen were immediately told off for the duty ; but, from the narrowness of the level, more than one of them was seldom able to work at a time. Notwithstanding the displacement of every stone occasioned some—and often dangerous—-movement in the mass, men were bold enough to worm themselves through the crevices, but they were unable to reach him; before the lapse of a second day, therefore, it was evident that there was no hope of his immediate rescue, and, at intervals, he became delirious. About this time an English Churchman present, suggested that the sufferer might probably be comforted by a visit from his Clergyman. This hint was at once reported to the Reverend James Power, R. C. Priest of the Parish, who, without hesitation, descended the mine, and administered the consolations of Religion to him as he lay. Some hours later the work had so far advanced, that small quantities of food were occasionally passed to him through openings between the stones, and about the end of the third day he was set free. His limbs, of course, were cramped from the straitened position in which he had been con- Copper-Mines in Ireland. 601 Some of the slates are interstratified with beds of conglomerate; * but, as these are unproductive within the area to which this memoir refers, a description of them is beyond its scope. Other rich lodes have been, from time to time, worked in Knockmahon , but the writer has had no opportunity of examining them. The mine afforded, from the beginning of 1825 to the end of 1865, Copper-ores which realized. £1,399,2321 The expenditure on } salaries, wages, & > ... amounted to £855,621 materials.) „ Royalties (Dues) . „ 54,458 „ Profit, divided 1 amongst the > ... „ 489,153 Shareholders. J - £1,399,232. The coast—presenting alternately caverned cliffs and sandy beaches—resembles the wildest and most desolate shores of West Cornwall. J fined, he was benumbed by long immersion, and weak from fasting; but other¬ wise he was unhurt. A weary time passed before his recollection returned; and he recovered his strength slowly: he never resumed his place underground; but he is still (1868) employed on light jobs at the surface. * “ In the townland of Ballynagigla, we find some beds of reddish con¬ glomerate and reddish-purple shale interstratified with a grey feldstone # # * when the 1 red ground ’ (the red conglomerates and shales of the Silurian rocks) was reached, under the crushing floors of the mine, the lode was lost, but it is supposed that to the north of these beds, under the name of the North Mine lode, it was recovered.”—Du Noyer, Explanations to accompany Sheets 167, 168, 178, # 179 of the Geological Survey of Ireland, pp. 57, 82. t Robert Heron, Esq., Secretary of the Mining Company of Ireland, MSS. Ante , p. 442, Table XIV. J Henwood, Cornwall Geol. Trans. , v. pp. 42, 113,— 30. PPPP 602 W. J. Henwood, on The Bearhaven Mines are wrought, at the head of Ballydonagan-bay near the western extremity of Cork, in rocks composed of siliceous matter mixed with chlorite, # talc, or some kindred mineral; traversed by microscopic veins of quartz; and sprinkled, at inter¬ vals, with the carbonate of lime. Such portions of them as adjoin rich parts of the lodes , are, in general, pale-buff, lilac, or dove-coloured, and of thick lamellar structure; but elsewhere they are blue and fissile.'}' The planes of cleavage—although in some places con¬ siderably curved—are, on the whole, nearly parallel to the Main lode in direction ; yet—maintaining a much higher inclination than it maintains—they dip some¬ times towards one side, sometimes towards the other, but mostly towards the north, j The lilac, buff-coloured, and blue slates alternate, here and there, with narrow * “ A mineral allied to chlorite, and seemingly that called an hydrous mica by Dana, is found abundantly in the quartz veins.”— Kinahan, Explanations to accompany Sheets 197, § 198 of the Geological Survey of Ireland , p. 29. f “ The dark blue varieties of the clay slate are considered by the miners un¬ favourable to the production of copper ores, whilst the gray, and particularly the buff kinds, as in Cornwall and elsewhere, are held to be congenial.” Smyth, Ibid, p. 30. “ In the two carboniferous troughs of Kenmare and Bantry H: % Hi the rocks consist of red, purple, brown, and greenish sandstones, sometimes becoming purplish grey, but never black or dark-grey, and they are variously interstratified with bright red, purple, lilac, greenish, and yellowish clay-slates. The slates occasionally predominate to such an extent as to cause the rocks to assume the character of a great clay-slate formation, the transverse cleavage cutting across the beds generally at a high angle, and with a steady strike of west-south-west and east-north-east, but dipping sometimes to one side and sometimes to the other side of their strike.” Jukes, Quarterly Journal of the Geological Society, xxn. p. 332. | “ All the rocks of the district have been tilted into very high angles oftener above 45° than below it, and frequently even 90° or vertical. They are bent and Copper-Mines in Ireland . 603 light-brown beds; traversed, lengthwise, by undu¬ lating, unconformable, interlacing joints, which divide the rocks into small, lenticular masses,* polished and grooved without, but of fissile structure within. Other, subordinate, quartzose beds, of blueish-green hue and uneven fracture, impoverish the lodes , wherever they touch them. Three series of joints—common alike to the rocks and lodes —bear respectively, 28°—38° W. of N.—E. of S.; 25°—30° N. of E.—S. of W .; and 15°—20° S. of E.—N. of W.f The different conditions of the two lodes —or, it may, perhaps, be said, of the two branches of the principal (Champion ) lode — wrought in the Mountain-mine \ are— The Main lode, bearing 25° N. of E. ] [ dipping N.) [andmeasuring 10—42feet — S. of W., ^ 60°—72°,^ * in width ; „ Mountain „ ,, 38° W. ofN. i [ dipping E. j [ ,, 20—62feet —E. of S.P <■ 62°— 78° ■> < in width. contorted in various directions, but generally strike with the mean run of the principal features of the ground, the lines of the shores and the crests of the hills, all ranging along lines which run nearly E.N.E. & W.S.W.” Juices & Kinahan, Explanations to accompany Sheets 197 1862 the Carysfort Mining Company \ o^.nnru extracted about...V * ” ” * Of the quantities procured by the English Mining Company , and by the poachers during their several incursions, it has been found impossible to procure account. || Whilst the officers of Government wrought the detrital deposits, they also attempted to find the parent “ This is equivalent (neglecting the iron) to 8^ atoms of gold and 1 [atom] of silver.”— Mallet, Journal of the Geol. Soc. of Dublin , iv. p. 271. * Weaver, Geol. Trans., v, p. 211. f “ The peasantry obtained about eight hundred ounces of gold during the [six weeks] they continued at work.” Mallett, Journal of the Geol. Soc. of Dublin, iv. p. 270. 4 “ The total quantity of native gold collected by Government [between 1796 and 1802] amounted to 944 ounces, 4 pennyweights, and fifteen grains, of which 58 oz. 16 dwts. 1 grain were sold as specimens at £4 the ounce, amounting in value to £236.10s. 8 d. The remaining 885 oz. 8 dwts. 14 grains, I melted and cast into ingots which weighted 848 oz. 18 dwts. 5 grains. Hence the loss in melting was 36 oz. 10 dwts. 9 grains, or nearly 4j per cent., which arose from disseminated particles of quartz. The ingots % # # were bought by the Bank of Ireland at prices varying from £4. 0s. 6d. to £4. 2s. 0 d. per ounce amounting in value to £343. 17s. 3 \d. Hence the aggregate value of the native and ingot gold was £3675. 7s, 11 §d.”—W eaver, Geol. Trans., v. p. 211. § “ This Company has long since ceased to search for gold in Wicklow, and has surrendered the Crown Licence. Long years and heavy cost of search pro¬ duced only 85 ounces of metal.” J. S. Hoare, Esq., Secretary of the Carysfort Mining Company , M.S. || “ Since the undertaking was abandoned by the Government, it has been attempted to work the same deposits by a company, but without success, partly, it may be presumed, from the rarity of the precious metal, and partly from the difficulty experienced in all gold-streaming or gold-digging regions of obtaining from the workmen the full produce of their labours. % % -ft TTTT 634 W. J. Henwood, on the rocks and veins; but without success.* * Indeed the only part of Wicklow which has yet afforded native gold in place is the Sulphur-course at Ballymurtagh ; and, even there, the small quantity hitherto obtaine d has not encouraged further search .f “ Of late years, only a few of the neighbouring peasants have from time to time been engaged in gold-washing, and it is very difficult to form a fair estimate of the remuneration yielded them by their labour.” Smyth, Records of the School of Mines, i. 402. * “ Numerous trials were made by driving and sinking on the veins previously known, and subsequently discovered. % % % By the Ballinvalley trench alone, twenty-seven veins of quartz were found, varying from nine inches to four feet wide, in a distance of 700 fathoms; and in the same manner, by the Ballinagore trench eighteen quartz veins were discovered in a distance of 600 fathoms. * * * The mineral substances obtained, were subjected to the operations both of fire and of amalgamation; but in no instance was a particle of gold elicited from them either by the one or the other process.” Weaver, Geol. Trans., v. pp. 210—12. t John Hodge, Esq., of Ballymurtagh , MSS. Ante , pp. 549—50. Clogau Gold-Mine, in North Wales. 635 Notice of the CLOGAU Gold-Mine, in North Wales. The Clogau gold-mine, some five or six miles W.N.W. of Dolgelly, and more than a thousand feet above the sea, is wrought in a lower part of “ the Silurian System.” # * “ The structure of this district is very singular, consisting of an immense number of alternate and parallel beds of igneous and sedimentary rocks, tra¬ versed by vast numbers of mineral veins, and trap dykes. # % % A complete system of auriferous veins exists throughout the Snowdonian or lower Silurian formations of North Wales.” Dean, Reports of the British Association, 1844, Part n. p. 56. “ On the N. & W. of the lower part of the River Mawddach lie the lower part of the Lingula-flags and the Cambrian rocks. The latter consist of coarse, thick- bedded greenish-grey grits. % H; % These are overlaid by that part of the Lower Silurian rocks known as the Lingula-flags, which here consist mostly of blue slaty beds, generally more or less arenaceous, and partly interstratified with courses of sandstone. % % * Both Cambrian and Silurian rocks have been penetrated by numerous greenstone-dykes. Many of them are of a light grey colour and highly calcareous. Others assume the colour and texture of ordinary greenstone. Some of them are magnetic. Amongst the Cambrian sandstones they run in all directions, sometimes with, but more generally across, the strike. In the Silurian region they more generally run more or less parallel with the lines of bedding.” Ramsay, Quarterly Journal of the Geol. Society, x. p. 242. “ The now celebrated Clogau Gold Mine situate % % % at an elevation of 1,000 feet above the level of the sea # # % about a mile and a half north of the ‘ Halfway House,’ on the turnpike-road from Dolgelley to Barmouth % % % [has been opened on] a quartzose vein which traverses altered palaeozoic slates near the junction of an eruptive bar of porphyritic greenstone.” Re ad win, Reports of the British Association , 1861, Part n. p. 130 ; 1862, Part n. p. 90. “ Halfway between Dolgelly and Barmouth an impetuous stream, descending from the high range of Llawlleeh, pours its waters over a rocky bed to join the Mawddach below Pontddu. On either side of this % % % river there rises a mountain, in which copper veins have, for many years, been worked on the west, the Vigra, and on the right [east] the Clogau. % % % [The lode intersects] dark schistose rocks of the lower silurian formation, with which are associated both interstratified and intrusive or dyke formed greenstones. On the north, at the distance of a few hundred feet, the massive greenish grits of the Cambrian system pass out from under the highly inclined beds of the lower silurian or lingula flags.”— Smyth, Mining and Smelting Magazine, I. p. 361. “ Originally the lodes of Vigra and Clogau were chiefly worked for copper, 63 6 W. J. Hen wood, on the Clogau The rock which accompanies the Saint David lode, —where, at intervals, its outcrop is exposed, at the surface, and in the S., lower, or foot-wall , of the upper (gallery) level, —consists principally of felspar and chlorite; mixed, however, with both siliceous and calcareous matter, and sprinkled with microscopic crystals of oxydulated iron.* In the opposite side (wall), on the contrary,—whilst similar ingredients occur here and there—homogeneous greyish-blue slate prevails; and in the lower level, some twelve or thir- with little or no profitable result, but about 1854 the discovery of gold in the rejected rubbish of the old workings at Clogau, and also in the abandoned lode, raised a kind of gold furor in North Wales. * * * Of late years, however, since 1859, the gold vein * * * which intersects the Lingula flags about a quarter of a mile farther north than the old Clogau copper lode near the outcrop of the Cambrian grits, has been worked to a great advantage.” Rams at, Memoirs of the Geological Survey , in. p. 47. “ Fragments of the great Paradoxides were found, at the famous gold-mines of Dolgelly, about the same time by Mr. Readwin, and by his assistant-chemist, Mr. Ez. Williamson.” —Salter, Quarterly Journal of the Geol. Soc., xxi. p. 477; Memoirs of the Geological Society , in. p. 247* J. Arthur Phillips, Mining and Metallurgy of Gold and Silver , p. 16. “ The geological position of the Clogau quartz lode is in the Lower Silurian Lingula-beds, close to their junction with the Cambrian strata of the Geological Survey, on which these beds rest conformably; and in close proximity to the lode they contain the Paradoxides Davidis in abundance. In these strata are seen numerous intrusive masses, and, as it were, sheets of true diabases (described, and coloured by the Geological Survey as greenstones) apparently at first sight contemporaneous with the beds themselves, but which, although frequently found to follow the strike of the fossiliferous beds for long distances, and even at times to coincide more or less with their dip, will nevertheless be sooner or later ob¬ served to break through both the strike and dip of these strata. * * * These diabases are composed of a felspar base in conjunction with diallage and chlorite, and frequently, owing to incipient decomposition of these silicates, effervesce slightly with acids, thus revealing the presence of a trace of carbonate of lime.” David Forbes, London , Edin., and Dublin Phil. Mag., Fourth Series, xxxiv. p. 339. * “ The Lingula flags as a whole may be described as * * * formed by the repetition of very numerous very thin, slightly waved felspathic and siliceous layers, of a light bluish grey colour.” Ramsay, Memoirs of the Geological Survey , in. p. 20. Gold-Mine , in North Wales. G37 teen fathoms deeper the same rocks appear. South¬ ward, however, felspathic and chloritic beds mostly of compact, but sometimes of fissile, structure, alternate with homogeneous, greyish-blue, clay-slates; the lode —from the obliquity of its range to theirs—intersect¬ ing them all in various parts of its course. The several planes, as well of bedding throughout the formation, as of cleavage in schistose parts of it, range from 15°—25° E. of N.—W. of S. to 30°—40° N. of E.— S. of W.; * within short distances of the lode they dip 70°—80° N., but where the mountain slopes towards the Mawddach—and beds of (diabase) greenstone are numerous—they have an opposite, although a lower, inclination.t Throughout the neighbourhood two series of joints prevail; one striking 35°—45° W. of N.—E. of S., the other 30°—40° N. of E.—S. of W.; beside others coursing 18°—25° S. of E.-—N. of W., —8—24° W. of N.—E. of S.,—and 14°—24° E. of N.—W. of S. respectively, but these seem of merely local occurrence. The lode bears 18°—28° N. of E.—S. of W.: J and —near the surface as well as at the upper level — * “ In 1840 the Magnetic declination was about 26° West.” Sabine, Phil. Trans., cxxxix. PI. XIV. t “ The dip of the cleavage [is] towards the south-east and north-west, but more frequently the former, in accordance with the average dip of the strata.” Ramsay, Memoirs of the Geol. Survey, hi. p. 22. $ “The auriferous veins of Merionethshire traverse two other sets of veins, and have an average bearing of N.N.E. and S.S.W., and like the others, with a north dip. These veins are very numerous, and are filled with argillaceous substances, iron pyrites, and iron and blende ores. In width they vary from f of an inch to 6 or 8 inches, but sometimes expand to 2 or 3 yards. In many cases they split into minute branches. Where the auriferous veins traverse 638 W. J. Henwood, on the Clogau certain parts are almost perpendicular whilst others dip 75°—85° N.; in the lower level , however, it de¬ clines—sometimes no less than 60°—70°—towards the S. Its width—ranging from a fraction of an inch upward—is usually from three to four feet. It con¬ sists for the most part of quartz, calcareous-spar, and —as the adjoining (Country) rock is of one kind or other—either felspathic and chloritic matter or homo¬ geneous dark-blue slate. The quartz and the calcareous- spar often occur separately ; but occasionally a body of one may include granules, small shapeless masses, and [certain of] the quartz veins they are generally very productive of gold, the quartzose veins, if metalliferous, becoming enriched on the south side of the intersection. The sides of the auriferous veins, where they pass through the quartzose veins, are generally cellular, and in the cells the gold is * * * for the most part deposited. * * * Some of the gold ores produce from [0-000004 to 0*001836 their weight] 3 dwts. to 60 oz. of gold per ton.” Dean, Reports of the British Association, 1844, Part n. p. 56. “ A quantity of what was called ‘ poor copper ore ’ was raised from c the Saint David’s * lode and sold many years since; but in 1854 this ‘ poor copper ore ’ was examined, and indications of native gold in considerable quantities were found.”— Readwin, Ibid, 1861, Part ii. p. 130. “ The St. David’s lode * * * in which gold had been found in 1854 * * * lies about a quarter of a mile further north than the Clogau copper lode, coursing in the same manner about E.N.E. by N. * * * The vein itself, where well de¬ veloped, is from 2^ to 9 feet in width, between distinct walls, especially on the south, underlying commonly to the north, but on the whole nearly perpendicular. It is composed of quartz and calcareous spar, the latter sometimes forming a body of several feet in width; and when the calcite puts on the appearance of a finely granular and friable marble, it frequently contains gold. * * * Spots of iron and copper pyrites are not unfrequent, and hence the lode was originally opened upon for copper, fragments of the more or less talcose schist of the walls; and sometimes in one part, sometimes in another, the * * * points and spangles of gold may be seen disseminated in the calc spar or quartz, often accompanied by bright white crystalline scales of the mineral of tellurium, sulphur, and bis¬ muth, called tetradymite. The laminae of the rocks which form the country on either side of the lode strike a few degrees more north of east so that they are intersected somewhat obliquely by the walls. * * * Planes of division nearly horizontal cross the lode from one wall to the other. These, in some veins, we may see to be filled with zinc blende or calc spar, * * * but at Clogau Gold-Mines in North Wales 639 short narrow veins, of the other, and sometimes the two are intimately mingled; at intervals also the rocky ingredients are sprinkled, veined, or transfused with either separately, or with an admixture of both. Pearl- spar, the sulphate of barytes, and other earthy minerals, appear here and there, but in much smaller quantities. At and near the surface earthy brown iron-ore abounds. In rather deeper, yet in comparatively shallow, portions of the lode , however, iron-pyrites and yellow copper-ore are—as amongst certain auriferous deposits in Brazil,* I have been unable to observe that the gold has any connexion with these com¬ paratively late fissures. There are [parts of the lode] where a mere thread of spar, or even a slight division only, * * * constitutes the only vestige of what, a fathom or two back, was a body of 9 feet wide. * * * [Moreover] one portion where the gold is visible, will be exceedingly rich; another, where, per¬ haps, it can be no longer seen, will pay; another will not contain a trace; and further, perhaps, the lode itself is for some distance entirely nipped to nothing.” Smyth, Mining and Smelting Magazine, I. pp. 361—2. (Abridged.) “ The auriferous quartz lode at Clogau runs about 18° north of east and dips at a high angle (88°) to the south cutting through both the fossiliferous strata and the intruded diabases; * * * . The mining explorations carried on hitherto appear to indicate that this quartz lode is much richer in gold at the parts where it cuts through the Lower Silurian Lingula-beds, with their accompanying in¬ trusive diabases, than in greater depth where it traverses the Cambrian grits.. The accessory minerals found associated with the gold were tetradymite, iron pyrites, galena, chlorite, calcite, dolomite, ankerite (?), chalybite, and sulphate of barytes. These minerals as well as the native gold itself are distributed very irregularly in the quartz. When the quartz contains patches of calcite, dolo¬ mite, and chalybite, and includes splinters of the neighbouring clay-slate, it is regarded by the miners as more likely to yield gold than when the lode consists of quartz alone. Although the gold sometimes is found alone imbedded in the colourless quartz, it occurs more often in conjunction with more or less iron pyrites, and other above-mentioned metallic compounds, which usually occur as small patches, nests, or aggregations in the quartz. When small pieces of the bluish-grey slate are found isolated and enclosed in the quartz of the lode, it is common to find the gold and other metallic minerals adherent to or crystallized on the under faces of such fragments.” David Forbes, London , Edin., and Dublin Phil. Mag,, Fourth Series, xxxiv. p. 339. (Abridged.) * Ante, Henwood, Cornwall Geol. Trans., vi. p. 144; London, Edin., and Dublin Phil. Mag., xxv. p. 342; Ante, pp. 194—5. 640 W. J. Henwood, on the Clogau Chili,* and the United States,!—freely, though un¬ equally, distributed; but, notwithstanding these are limited to neither of the vein-stones, they prefer a quartzose to either a sparry or a felspathic matrix. Small quantities of blende occur frequently; particles of galena are widely scattered ; and—accompanied by many of the minerals which accompany tellurium J and various ores of Bismuth § in the gold-fields of Minas Geraes and Virginia,—minute crystalline scales of tetradymite present themselves in distinct clusters. Both the quartzose and the sparry ingredients — whether separately aggregated, or mingled in different proportions—contain, at intervals, particles and grains of gold, and are intertwined with golden threads which unite in small nuggets at their reticulations; occasion¬ ally also isolated atoms of the metal are confined to certain lines, which differ in no appreciable respect from contiguous portions of the vein-stone. The gold may, perhaps, be less abundant, but—as in different parts of the calcareo-siliceous bed which underlies the jacotinga in Co cats || and Gongo —it is of coarser grain, in sparry, than in quartzose, sections of the deposit.** Granules and scales of gold some- * Domeyko, Annales des Mines, 4me Serie, ix. pp. 368—9. Caldcleugh, Travels in South America, 1.351. Sampson Waters, Esq., MSS. Ante, pp. 167, 378. f Ansted, Scenery , Science, and Art, p. 288. Henwood, Mining Journal , 29th January, 1853. Whitney, Metallic Wealth of the United States, p. 128, X Henwood, Cornwall Geol. Tratis., vn. p. 229; Ante , pp. 180, 299, 336—82. $ Ante, pp. 179, 336. || Ante, p. 245, If Ante, p. 249. ** Henwood, Reports of the Imperial Brazilian Mining Association, xli. p. 8. Gold-Mines in North Wales 64 i times adhere to, but they are seldom imbedded in, the slaty constituents. If, as seems likely, the iron and copper pyrites contain gold,* it is—as at Morro Velho f—masked by its matrix ; under proper treat¬ ment, however, profit is often made by the extraction of metal from a vein-stone in which the unaided eye fails to detect it.*J From the middle of June, 1860,§ to the end of December, 1867,|| the mine supplied tons ( Avoir .) 9,181-6518 of ore, which yielded.. 179-1512 lbs. (Troy) of gold,[| & 127-4308 II .. 929-6384 „ „ ,|| total.. 9,309*0826 II 1,008-7896 „ „ ;|| the first having afforded .. 112-39 || grains of metal j per ton ,' [ or 0-00000717 itsweight 1 of gold, ,, second XT) pan >> • • 4,202-06|| 686-06|| 36-00|| II II „ 0-00198461 „ , „ 0-00004375 „ ; „ 0-00000230 „ the poorest! parcels 1 )> • • >1 II II II „ richest ,, II 717,600-00(1 II II „ 0-04576530 „ . * In 1836 specimens of copper pyrites, represented to contain gold, were shown to the writer at Cae Mawr near Tyn-y-croes by the late Mr. Charles O’Niel. Ramsay, Quarterly Journal of the Geol. Society , x. p. 243. Readwin, Reports of the British Association, for 1862, Part it. p. 89. ce The pyrite of most gold regions is auriferous. The fact is not apparent in any of the external characters.”— Dana, Mineralogy, fifth Edition, p. 63. f Henwood, Cornwall Geol. Trans., vi. p. 144. London, Edin. § Dublin Phil. Mag. xxv. p. 342. J The Brazilians burn their worn-out bateas, in order to recover from the ashes the particles of gold which are always imbedded in the wood during use. § Readwin, Reports of the British Association, for 1861, Part n. p. 130; for 1862, Part n. p. 90. Smyth, Mining and Smelting Magazine, I. p. 364. Hunt (Phillips’s), Mining and Metallurgy of Gold and Silver, p. 16. || Accounts of the Mine, obligingly supplied by Robert Gillman,Esq., Managing Director of the Vigra and Clogau Mining Company. “ The quantity of gold raised from this lode between April 1860 and May t uuuu 642 W. J. Henwood, on the The gold averaged twenty-two carats fine.* f The confronting Table (XXII.) shows the quan¬ tities and proportions of gold obtained from the detrital deposits and vein-stones of various Countries. 1867, as officially accounted for to Her Majesty’s Office of Woods and Forests, is 12,416 oz.” [1,034-666 lbs. Troy]. Murchison, Siluria, fourth Edition, p. 450. * Ante, p. 641, Note ||. f Two specimens of gold from this submitted to examination afforded Gold.. .. I. _ 90-16 II. .... 89*83 Silver.... .... 9-26 .... .... 9-24 Copper and iron .... . Quartz. _ 0-32 .... 0-74 Loss in analysis ...., .... 0-26 _ 0-19 100- 100- David Forbes, London, Edin. 8$ Dublin Phil. Mag ., fourth Series, xxxiv. p. 339. Chrome-ore of Breadalhane. 643 On the Chromate of Iron (lately) wrought at Corri Charmaig in Perthshire. Amongst the many metalliferous deposits laid open by the late Lord Breadalbane* —for sake of employ¬ ing the working population on his vast estate,f—some have been more valuable,J but none are more interest¬ ing than is the chromate of iron wrought, from time * John fifth Earl and last Marquis of Breadalhane, P.C., K.T., F.R.S., Lord Lieutenant of Argyllshire, President of the Society of Scottish Antiquaries, &c., &c., &c., who died in 1862.' t w -vr w E.—N. of W. ’ ” vv.—i>.w.; but, notwithstanding this convergence,—no less in their descent than in their course towards the S.— * Ante, p 643, Note f f “ At Tomnadashin # # # the veins contain rich copper-pyrites, iron- pyrites, and some sulphuret of molybdena. The veins which contain quartz of calc-spar yield grey copper-ore, rich in silver and copper; from these a great number of branches are sent off in all directions.” Odernheimer, Quarterly Journal of the Highland and Agricultural Society of Scotland , xi. p. 528. “ In the mines of Tomnadashan several # & # divisions, which have received the general name of clay-veins, may be seen, forming very regular courses both in perpendicular and horizontal directions, They are receptacles of * * * silver-ore, copper-pyrites, grey copper-ore, iron-pyrites, and molybdenite.” Thost, Quarterly Journal of the Geol. Soc., xvi. pp, 422—3. of Tomnadashan in Perthshire. 653 S.E.,—operations have never been extended to their contact.* In width they vary from about six inches to nearly four feet. Whilst traversing the greenstone, their principal earthy constituents are felspar and hornblende; but, in the porphyry, they consist chiefly of felspar and granular quartz; everywhere, however, massive quartz is a large ingredient, and smaller quantities of cal¬ careous-spar and of chlorite are not uncommon. As the lodes converge, the rock between them is intersected, in every imaginable direction, by number¬ less intertwining veins of felspathic, quartzose, horn- blendic, calcareous, and chloritic matter; usually a mere fraction of an inch, though sometimes several feet, in thickness. But, notwithstanding these inter¬ laced portions may not transgress the limits of the greenstone formation, the general prevalence of horn¬ blende within them, and of felspar towards their surfaces, gives the entire mass a brecciated character. Both the lodes and their branches f contain, near the surface, great quantities of earthy brown iron-ore, small bunches of copper-pyrites, and nests filled with earthy black copper-ore or studded with malachite ; downward, however, the earthy ore is gradually re¬ placed by iron pyrites; yellow copper-ore becomes * “ When the miners are working along on the course of a lode, ever so good., and they find it separate and diverge into branches or strings, it is a great sign of its poverty; but, on the contrary, if they are driving on branches of ore, and they find them embodying or coming together, as they work on the course of the lode, it is promissing.”—P ryce, Mineralogia Cornubiensis , p. 103. f Ante, p. 652, Note f. 654 W. J. Hen wood, on the more plentiful, and granules of fahlerz together with particles of galena are thinly sprinkled through the matrix. The sulphuret of molybdenum—masked, possibly, by other substances—is seldom observed in the lodes; but—accommodating itself to the striae, which score the vein-stones and the (Country) rocks at their con¬ tact—it, not uncommonly, shows itself as a slickenside. On the margin of the lake, however, small tabular crystals are scattered through the porphyry and face its joints.* J Molybdenite occurs on the Syenite (or granite) of Mount Sorrel. Foster, Geological Magazine , in. p. 525. “ Fine hexagonal plates of Molybdenite, with the terminal edges replaced, and of from ^ to § an inch in diameter, occur thickly embedded in a quartz vein traversing granite at Yackandandah; it also occurs in a similar manner at Reedy Creek, and very sparingly dispersed in small scales through the granite at the breweries near Maldon. The Yackandandah mineral contains, according to assays, a small per-centage of silver.”— Selwyn & Ulrich, Notes on Physical Geography, Geology , > 010 . )> 0*26 ..'_ .... 0*14 0-07 . .... 0*12 M 0*04 .. .... 0*03 )7 1* Cornwall Geol. 1- Trans., v. Table XC1X. f In 1840 the magnetic declination was 25° W. 5 A Sabine, Phil. Trans ., cxxxix. p. 205, PI. XIV. 674 W. J. Henwood, on the Caradon ( f ) In the slate of Crow’s-nest, Caradon Down, Marke Valley , Caradon Coombe, Phoenix, and Wheal Jenkin, about 0-60 of the principal joints bear .... 14°—24° W. of N.—E. of S. „ 0-20 „ .... f40° W. of N. E. of S. (20° N. of W.—S. of E. „ 0-20 „ .... f E-—W. _ 140° N. of E.—S. of W. 1 * other joints, which have different directions,* are of shorter range. (e —1) The lodes range between 5° S. of E.—N. of W. and 35° N. of E.—S. of W., 0*08 of them bearing 5° S. of E.—N. of W. — E. & W., 0-08 „ E.&W. — 10° N.of E.—S.of W., 0-32 „ . io°—20° N. of E.—S. of W., 0-48 „ . 20°—30° „ — „ , 004 „ . 30°—40° „ — „ , their mean direction being about 18° N. of E.—S. of W.t (—2) Notwithstanding both the bedding of the Cheesewring granite J and the cleavage-planes of the neighbouring slates <§ dip from the central body of the great granite formation, * Haughton. Phil. Trans., cliv. pp. 405— 7- f “ The general bearing of the copper lodes averages about 7 degrees north of west & south of east ” [magnetic]. —Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District , p. 5. The mean d rection of the lodes in the Helston district is 16° N. of E.—S. of W. Camborne Redruth St. Agnes St. Austell Callington & Tavistock 99 99 99 9 ) 99 20 ° 22 ° 22 ° 13° 9° 99 99 99 99 99 99 99 99 99 t Ante, p. G72. Henwood, Cornwall Geol. Trans., v. p. 250, Table CIII. $ Ibid, p. 673. District in East Cornwall. 675 only 0*04 of the lodes severally described (in Tables XXIII.—XXVI.) whilst 0*96 ,, | dip from * ,, towards * the granitic mass; meanwhile the bedding of one rock dips 5°—10°,f an d the cleavage of the other 12°—20°; J the (opposite) inclination of the lodes averaging 69°—70°. § (—3) The lodes which traverse dissimilar rocks differ—here as elsewhere ||—in width; thus— those partially or wholly'} few to offer noteworthy ( ran « e from 1 foot t0 10 feet & avcra S e 6 ' 8 feet in width * results . ) whilst the lodes peculiar i to the granite ..*...5 ” » 12 o.n )) M ^ u the mean width, throughout the district, being about . 3 # 2 „ IF (—4) The lodes —comprehending every ingredient of the rocks they traverse, although differently aggre¬ gated and in different proportions, — consist chiefly of quartz, chlorite, and felspar; associated, at intervals, with smaller proportions of mica and schorl. Some¬ times the three principal of these constituents, but perhaps more frequently two of them indifferently, are intimately mixed; and, occasionally, this incorpo¬ ration is veined or sprinkled with the same substances * “ Of 296 examples, 162 [0-55] dip towards, and 111 [0*37] from the nearest granite, whilst there are 23 [0‘08] doubtful cases.” Henwood, Cornwall Geol. Trans., v. p. 245. f Ante, p. 672. + Tables XXV.—XXVI. §“ Throughout Cornwall and the west of Devon, the mean dip of the lodes may be about 70° from the horizon.” Henwood, Cornwall Geol. Trans, v. p. 247. |] “ On the whole the lodes which occur in the granite are smaller than those in the slate.”— Ibid, p. 241, H The average width of the lodes in the Saint Just, Saint Ives, Marazion, Gwinear, Helston, Camborne, Redruth, Saint Ives, Saint Austell, Callington, and Tavistock districts is about 3*61 feet.”— Ibid, Table Cl. 676 W. J. Henwood, on the Caradon in different degrees, with either of them separately, or —in the S. of the district—with fluor.* * * § ** As well N. as S. of Caradon the shallower parts of the lodes contain, at times, considerable quantities of earthy brown iron-ore; but it, and the minerals which accompany it, are not of precisely the same character on opposite sides # of the granite. (■—4 1 ) Stowes,f Phoenix, J South Phoenix ,§ JDuns- ley Phoenix , § and Marke Valley ||—wrought in the granite or in the slate adjoining it,—afford iron-ore of dark-brown — occasionally, indeed, of blackish — hue, scattered through hard, massive, though fre¬ quently cavernous, quartz, and mixed—downward especially — with chlorite. In a matrix of this character, these (N.) lodes have—perhaps for ages ## * “ Fluor-spar, found plentifully in most of the southern lodes, has never been seen at the Phoenix Mines.”— Webb & Geach, History and Progress of Mining in the Caradon and Liskcard District , p. 28. t Ibid , pp. 28—30. Allen, History of Liskeard, p. 395. t Ante, pp. 657,—69, Table XXV . § Ibid, p. 668. || Ibid, pp. 659,-67,-71, Table XXVI. IT “ At the Stow’s Mine West, the lode contained towards the surface immense masses of highly ferruginous gossan, becoming, however, as it approached Clanacombe Mine [E.], less impregnated with iron Hi Ht Ht . In depth the matrix is generally composed of blue capel, carrying a leader of quartz and iron Ht Ht # . There is a little chlorite.”— Webb & Geach, History and Progress of Mining in the Caradon and Lisheard District, p. 30. “ A Scovan lode, is found of hard compact crystalline Stone, either of a brown or black hue, according to the colour of the Tin with which it is mixed. Ht Hi Ht Sometimes the Scovan tin lies in a less solid Lode, which is cavernous and full of holes, thence called a Sucked Stone by the Tinners.” Pb,yce, Mineralogia Cornubiensis, p. 90. Henwood, Cornwall Geol. Trans., v. pp. 226—8. ** “ North Phoenix Hi Hi Hi was worked by the old men about 150 years ago for tin.”— Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District, p. 57. District in East Cornwall 677 yielded an abundance of tin-ore.* Softer and lighter- coloured varieties of iron-ore, mixed with granular quartz, are impregnated with earthy black copper-ore, the red oxide of copper, malachite, Tamarite, chryso- colla, vitreous copper, and tile ore.f (—4 2 ) At Marke Valley J the lodes —as they tra¬ verse the slate—cease to yield earthy iron-ore within short distances of the surface, and thenceforth consist of quartz, chlorite, and felspar, mixed in various parts with different proportions of iron-pyrites, copper- pyrites, and tin-ore; sparingly, and at wide intervals, sprinkled with minute nests of earthy black copper- ore. A mere congeries of small veins represents the Sarum lode on the confines of the elvan-cowr&e ; but within it they reunite, and the lode assumes, at least, its previous width. *“The [Stow's] lode—backed up to the surface—was laid open by the old men for about a mile in length in their efforts to discover and raise tin, large quantities of which they returned.”— Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District, p. 28, “ The first [steam]-engine in the Liskeard district was [erected] at Stowes; but the mine was stopped and the materials were stolen about 1825.” Allen, History of Liskeard, p. 427- “About 1836 Hi Hi Hi considerable quantities of low-priced tin ore were raised from the Stow’s Mine. Hi Hi Hi About [1842] the Wheal Jenkin lode afforded, above the adit, large quantities of low-priced tin-stuff.”— Webb&Geach, History and Progress of Mining in the Caradon and Liskeard District, pp. 28—66. As late as 1851 the remains of at least a dozen stamping-mills were yet visible in various parts of Caradon-coombe, between Shilston’s-gate and Marke Valley ; in 1867, however, most of them had disappeared. f Ante, Tables XXV., XXVI. J “ Marke Valley was sunk Ht Ht Hi to the 26 [fathom-level], and about 1838 a small quantity of copper-ore was returned.”— Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District, p. 25. Allen, History of Liskeard, p. 421. Ante, pp. 659,—67,—71, Table XXV\ 678 W. J. Henwood, on the Caradon At Phoenix * * * § —in the granite,—on the contrary, the lode is still charged with earthy iron-ore, as well as with native copper, earthy black copper-ore, malachite, vitreous copper, copper-pyrites, and tin-ore, to the very bottom of the mine. (—4 1 ) The outcrops (hacks) of the more numerous, but narrower, lodes , opened in the S. slope of the granite at West Caradon f and South Caradon ,£ con¬ sist of soft, pale — and occasionally reddish-brown iron-ore,§ granular and friable quartz, granitic matter, chlorite in small quantities, and fluor at intervals. Where a cellular structure prevails nests of felspar- clay, earthy black copper-ore, and malachite are not uncommon; elsewhere the same vein-stones enclose * Ante , pp. 657,—69, Table XXV. f Ibid, pp. 661,-70,-1, Table XXIII. x Ibid , pp. 661,-70,-1, Table XXIV . § “ The discovery of gossan (or oxide of iron) very near the surface, in places where the ground was broken, on and near the Caradon hill, prompted the driving of several levels into the sides of this and adjacent elevations. They were re¬ linquished, however, by one party after another without success.” Allen, History of Liskeard, p. 396. Phillips (W.), Geol. Trans., n. pp. 117,—26. Came, Cornwall Geol. Trans., ii. p. 122. Fox, Reports of the Royal Cornwall Polytechnic Society, iv. p. 85. Ansted, Quarterly Journal of the Geol. Society, xn. p. 149 ; xm. pp. 245,— 49,-51. “ The Tender Red Gossan is very much inclined to produce Copper-ore, especi¬ ally if the Gossan be spungy, cellular, and of a very red colour, like to a well- burnt brick. When it is thus, and spotted, or tinctured with green Copper-ore, like pieces of Yerdigrease, it does not often deceive the proprietors. So, like¬ wise, Stones of blue or black Copper-ore, or of yellow ore having a black or purple outside, are very hopeful to follow when mixed with this Gossan.” Pryce, Mineralogia Cornubiensis, p. 88. “ The lodes which yield copper-ore in granite almost always contain gossan near the surface, and it usually continues to somewhat greater depths than it does in slate.”— Henwood, Cornwall Geol. Trans, v. p. 227. District in East Cornwall . 679 also small shapeless bunches of vitreous copper, copper- pyrites, # iron-pyrites, and mispickel; and masses of native metal, encrusted with crystals of ruby-copper, and invested with earthy black copper-ore, are of casual, but less frequent, occurrence. (—4 2 ) In the deeper parts of both mines quartz, felspar, chlorite, and occasional masses of granite, are still the chief ingredients; but earthy brown iron-ore —although yet observable here and there—is less plen¬ tiful than it had previously been, whilst fluor—on the contrary—is much more abundant. The proportions of vitreous copper, earthy black copper-ore, and malachite decline at the same time; and ruby copper as well as the native metal—still dwindling as the depths increase—at length disappear; in copper- pyrites, however,—as in fluor—the deepest parts of the lodes are the richest. Whether at smaller or greater depths these (S.) lodes give little or no tin-ore. It appears, therefore, that the lodes of Stowes , Phoenix , South Phoenix , Dunsley Phoenix , and Marke *“ Dark grey crystals of copper-glance are often deposited on low six-sided prisms, which, in respect to form entirely agree with that species. Their surface, however, is never perfectly smooth. On breaking them they do not present a uniform appearance ; generally the portions nearest the surface consist of the reddish metallic substance of variegated copper, whilst the rest possess the grey colour and conchoidal fracture of copper-glance. % % % On breaking the six- sided prisms here alluded to, I found a stratum of copper pyrites contiguous to the surface, whilst the rest consisted of variegated copper. Ht % # The speci¬ men [was] covered with black pulverulent oxide, but the surface of another was perfectly bright. % % % These changes can be explained upon the supposition that the copper contained in the original species has been replaced by iron, in a smaller quantity however, as every particle of iron required twice the quantity of sulphur to be converted into protosulphuret in the variegated copper, and four times the quantity for that portion of it in the state of copper pyrites.” Haidinger, Edinburgh Journal of Science, vii. pp. 131—2. (Abridged.) 680 W. J. Henwood, on the Caradon Valley (N. of the Caradon granite* * * § ** * * §§ ) have afforded— beside copper and several of its ores,—large quantities of tin-ore, # but contain no fluor: f whilst the lodes of West Caradon J and South Caradon § (S. of the Caradon granite) have yielded copper, copper-ore, and fluor in very great abundance; || but, notwithstand¬ ing the immediate vicinity of stanniferous granite at Gonamina —they give little or no tin-ore. ## (—5) The joints of one well-developed series ft have the same directions as many of the lodes,%% and often traverse them lengthwise; not uncommonly, indeed, the same lode is thus divided, by several such undulating joints into several subordinate veins, combs , or slices, of unequal thickness. §§ This structure, * Ante, p. 676. t Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District , p. 28. Ante, p. 676, Note * ; pp. 676—7. X Ibid, p. 678, Note f . § Ibid, Note \ . || Ibid, pp. 678—9. H Ibid, pp. 664—5. ** “ Ainsi tous les araas stanniferes connus sont caracteris^s par la presence du fluor : la proportion de cette substance est souvent considerable, se on la com¬ pare, non au volume total de 1'amas, mais a la quantite d’etain qui se trouve dans ces gites.”— Daubree, Annales des Mines, 3me Serie, xx. p. 101; Ibid, 4me Serie, xvi. pp. 130—7. tt Ante , p. 673. XX Ibid , p. 674. §§ Pryce, Mineralogia Cornubiensis, p. 95. Werner, New Theory of the Formation of Veins, pp. 83,—7. Phillips, (W.) Geol. Trans., ii. p. 138. Thomas, Report on the Mining District from Chasewater to Camborne , pp. 19— 20. Carne, Cornwall Geol. Trans., it. p. 120. Fox, Report of the Royal Corn- zvall Polytechnic Society, iv. pp. 85,—9. De la Beche, Report on the Geology of Cornwall and Devon, &c., pp. 339—45. Henwood, Cormvall Geol. Trans., v. p. 232; Ante, pp. 418,—33, 648. District in East Cornwall . 681 however, seldom extends beyond limited portions of th e lodes; for—-as in the rocks—after comparatively short ranges, the joints gradually disappear. Some¬ times each subordinate or constituent vein is character¬ ized by certain peculiarities of composition or arrange¬ ment; still, every lode has—so to speak—a distinctive physiognomy of its own. # Many—but especially the shallower and the poorerf —parts of most lodes abound in (vughs) cavities lined with crystals of quartz, which are often encrusted with ruby copper and virgin metal, where the Country is granitic; but more frequently with iron-pyrites and copper-pyrites when it is of schistose structure. ( f —1) The cross-courses —maintaining much the same direction as one well-pronounced series of joints J —range from 6° E. of N.— W. of S. to 24° W. of N. —E. of S.; and, on an average, bear 13° W. of N.— E. of S.§ ♦Henwood, Cornwall Geol. Trans., v. pp. 208 ; Ante , p. 89. f Henwnod, Edin. New Phil . Journal, xxn. pp. 157,—271 , Annals of Elec¬ tricity, i. p. 125; Annales des Mines, xi. p. 587; Cornwall Geol. Trans., v. p. 195. J Ante, p. 673. § The me a n direction £ ^ Saint Just district is 20° N. of E.—S. of W of the cross-veins ) ’ the average of the whole being 5 B Saint Ives Marazion Gwinear Helston Camborne Redruth Saint Agnes Saint Austell Callington & ^ Tavistock S j> 77 77 77 7 ) 97 38° S. of E.—N. of W., 41° S. of E.—N. of W., 43° W. of N.— E. of S., 21° S. of E.—N. of W., 34° W. of N.—E. of S., 35° S. of E.—N. of W., 39° W. of N.—E. of S., 21° S. of E.—N. of W., 43° S. of E.—N. of W., . 38° S. of E.—N. of W. Henwood, Cornwall Geol, Trans., v. p. 279. 682 W. J. Henwood, on the Caradon (—2) The cross-courses —more highly inclined than the lodes * * * § ** dip, on an average, just 80° from the hori¬ zon ; and—like the lodes on both sides f—underlie towards the great body of granite.J (—3) The cross-courses , which are rather broader than the lodes, §—as well in this neighbourhood as in other mining districts of the W.||—vary from 24 feet to 0*6 foot, and average 4*6 feet in width. (■—4) The cross-courses-y&rtdikmg, in some measure, the nature of the formations they traverse—consist of granitic matter when in granite,and of elvan when in elvan; but—differing in this respect from the lodes , which contain larger proportions of quartz ## —they are usually more felspathic than the (Country) rocks. Moreover, in the positions of the crystals of felspar they include, there seems an occasional approach to *“To whatever point the cross-courses may incline the amount of their in¬ clination is, on the whole, considerably greater than that of the lodes , and, on an average, is probably little, if at all less, than 80°,” Henwood, Cornwall Geol. Trans. , v. p. 277. Ante, pp. 408, 526—7. f Ibid, p. 675. + “ In 165 examples, 75 (0*46) dip towards, ) , 61(0-37) „ from, } the granite, and there are .29 (0-17) doubtful cases.” Henwood, Cornivall Geol. Trans, v. p. 277. § Ante, p. 675. || In the districts of Saint Just, Saint Ives, Marazion, Gwinear, Helston, Camborne, Redruth, Saint Agnes, Saint Austell, Callington and Tavistock the cross-courses range from 0-8 foot to 19 feet, and average 4*03 feet in width. Henwood, Cornwall Geol. Trans., v. Table CIV. U “ In the granitic tracts many of the cross-veins consist almost entirely of granitic matter; this is commonly in a state of disintegration, and often con¬ tains much more felspar, and occasionally more mica also, than the contiguous rocks.”— Ibid, p. 262. ** Ante, p. 675. District in East Cornwall. 683 uniformity.* * * § ' They—like the lodes —occasionally en¬ close masses (horses) of the rocks. (—5) Every cross-course is traversed by numerous longitudinal joints,f of which the flexures and con¬ sequent intersections divide it into lenticular masses and subordinate veins of unequal widths. J Such joints mostly present glossy faces of clay ; which, even within short distances, are often marked with uncon- formable striae, and on the opposite sides of the self¬ same masses and veins are, sometimes, thus scored in contrary directions.^ In all parts of this district the cross-courses have a • W.,|| and the lodes —with but one exception—a N.,^f dip. All (displacements) heaves , at the intersections of the lodes by the first** and thirdtt cross-courses 1 (counting from the W.), are—save \ towards the (R.) right-hand; ft in a single instance .j * Henwood, Cornwall Geol. Trans., v. p. 262. f Ante , p. 680. J “ One of the most remarkable features in the structure of cross-veins is the prevalence of joints; varying, however, in direction and dip, but preserving certain limits; so that, whilst they intersect each other, their curvatures seem projected on the same lines, which are in fact the directions of the cross-veins.” Henwood, Cornwall Geol. Trans., v. p. 260. Ante , pp. 13, Fig. 2; 648. § “ On the eastern side of Tregoning-hill the faces of the joints in the granite are irregularly striated, like those of slickensides on the walls of many lodes.” Henwood, Cornwall Geol. Trans., v. pp. 53, 172,—81—2. Ante, pp. 13, 469, 552—3, 654,—64. J] Ibid, p. 682. 1l Ibid, p. 675. ** The cross-course in West Caradon, Table XXIII. tt The Little W. cross-course in South Caradon, Table XXIV. XX Rryce, Mineralogia Cornubiensis, pp. 98—9. Thomas, Survey of the Mining District between Chasewater and Camborne , p. 22. Ante, p. 183, Note f. 684 W. J. Henwood, on the Caradon those at intersections by the second* and fourth, f" are — on t the contrary—always.) every (displacement) heave, however, is towards the (L.) left-hand ,, side of the (G.A.) greater angle.$ But intersections are not in all cases accompanied by (displacements) heaves, for in 33 instances 3 (or 0*11 of them) the cross-courses simply cut through,j i 0 ^ es .x without \ n * 14 ( ,, 0-41 ,, ) the heaves were towards the (R.) right-hand; § and 16 ( ,, 0*48 ,, ) „ „ (L.) left- „ .) The average extent of the heaves is ...about 13-0 feet; |( „ those towards the (R.) right-hand are „ 11*1 ,, ; || » „ (L.) left- „ „ 13-7 „ . (I The cross-courses —as already mentioned— * The Great cross-course in South Caradon, Table XXIV. f The Middle cross-course ,, , „ . J Ante, p. 683, Note , § The following columns show the results of the intersections of lodes by cross-courses in the W. districts generally :— Heaves. Metalliferous character of lodes. Simple intersections Right-hand (B 0 Left-hand (L.) Greater- angle (G.A.) Smaller angle (S.A. Copper lodes .... 0-177 0-524 0-298 0-742 0-088 Lodes yielding both 0-372 0 440 0 186 0-560 0 068 copper & tin ores .. Tin lodes . 0-180 0560 0-260 0-520 0-300 Means . 0-227 0-511 0-262 0-635 0-129 Hen ■wooi ), Cornwall Geol. Trails i, v. pp. 286- —7; Ante ,; op. 128—9 |) In the other W. districts the mean distance of the heaves of all the lodes is. 16*4 feet; ) ,, towards the right-hand . . 187 „ 11 11 11 left- „ . 12-0 „ 11 1 11 greater angle 11 1) 11 smaller ,, • •••••a* 17 1 99 lbidy p. 287 . District in East Cornwall. 685 feet maintain, on, the whole, a mean width of 4‘6,* * * § J those of them, however, which exceed the mean. and the heaves they ) occasion average f feet 13 0; preserve (amongst themselves) ,, 10*6, i ,, 20-1; J whilst such as fall short of the mean, measure (inter se) .. .. ,, 2*7, $ ,, 10*1. J The widths of the cross-courses , and the extent of the heaves which attend them, at different depths,^ are shown in the following columns;— Depths. Cross-courses. Heaves. fms. Widths,—feet. Extent,—feet. Surface to 80. 54 13*8 80 „ 100. 4T 12-0 ( ; g —1) The Great Spar-course which, in South Caradon , bears 20°—24° W. of N.—E, of S., is nearly perpendicular, measures between two and three feet in width, and consists of quartz mixed, occasionally, with earthy red iron-ore, intersects, but does not (displace) heave the Great cross-course. II %* * Ante , p. 682. f Ibid, p. 684. $ The average distance of the heaves by cross-veins less than 1 foot wide, is . 12'5 feet; more than 1 foot wide, ,, . 23 0 ,, . Henwood, Cornwall Geol. Trans., v. p. 298. § Throughout the other W. districts the mean distance of the heaves of lodes is . at less than 100 fathoms deep they are heaved . ,, more ,, 100 fathoms ,, ,, .. The mean breadth of the cross-veins at less than 100 fathoms deep is ,, „ more than 100 ,, „ 16’4 feet; 153 >» > 17-2 * }> 3-9 >> 9 4-4 9i • Ibid, p. 306. || “ At Polladras Downs the eastern (vein of clay )Jlucan intersects the quartz- ose cross-course , but occasions no (displacement) heave.” Ibid, p. 295, Table XLV*. 686 W. J. Henwood, on the Caradon No slide has been observed in the district.* * * § Notwithstanding the extent of early tin-mining^ in the district,—that the springs which have supplied water for household use now yield considerable pre¬ cipitates of copper,\—and that copper-mines had been so long,§ so largely, and so profitably wrought, as * “ The slides, hitherto observed Hi Ht Hi intersect only the schistose rocks and the elvans, and other veins traversing them; whilst there is not a single well-marked instance of a slide in the granite, or the massive rocks of the slate formation, yet known in any part of Cornwall.” Henwood, Cornwall Geol. Trans., v. p. 282. t Ante, pp. 676—7. “ The water which now gives a remunerative precipitate of copper, was formerly drank by the people of Crow’s-nest. Hi Hi % . The iron-work of the pump which supplies my house, is covered with precipitated copper.” John Taylor, Esq., Purser of Craddock Moor , MSS. Ante, pp. 585,—92. § The following statements, of writers on early copper-mining in Cornwall, can scarcely be read without interest. (1) “ Copper is found in sundrie places, but with what gaine to the searchers, I have not been curious to enquire, nor they hastie to reueale. For at one Mine (of which I tooke view) the Owre was shipped to bee refined in Wales, either to saue cost in the fewell, or to conceale the profit.” Carew, Svrvey of Cornwall (1602), p. 6. (2) In Kea “ the waste land of [Blanchland] is not only abounding in tin and tin mines, but for about twenty years last past hath yielded its owner about twenty thousand pounds out of its copper mines, though the Ht Ht Hi land in which it is found, is in many places scarce worth eighteenpence per acre.” Hals, Parochial History of Cornwall (1685—1736, Edited by Davies Gilbert, D.C.L., P.R.6.), ii. p. 300. (3) “ Within these sixty years, Copper has turned to very great account in this county ; and there have been very great discoveries made therein, both in the eastern and western parts of it, which have produced most of the varieties of ore found in Sweden, Germany, Hungary, and elsewhere : such as Yellow (which is the most plentiful and common of any). Green, Blue, Black, Ash- colour, and Solid ore. Hi Hi Hi This variety of ores, and great increase of the mines, has occasioned the setting up of six several companies for buying of the ore.”— Tonkin, Parochial History (1702—33). Carew, Survey of Cornwall, Edited by Lord De Dunstanville, p. 21. (— a) “ In [Kea] parish lies the extensive manor of [Blanchand] Hi Ht Ht which within these fifty years brought [the family of Boscawen] more money for copper than almost all the other mines in the county together, if the last fifty District in East Cornwall 687 well on both sides of the Tamar, as in many parts years are excepted, during which time great discoveries have been made in various other places.” Tonkin, Parochial History (1702—33, Edited by Davies Gilbert, D.C.L., P.R.S.), ii. p. 302. (41 “ Being sollicited, about twenty years since, to make a collection of Cornish fossils, for Dr. Boerhave, Dr. J. E. Gronovius, Dr. Linnaeus, and the late Dr. Isaack Lawson, then at Leyden, and finding the natural products of this County much commended ; and being also frequently employed afterwards in the same office, I became more and more fond of collecting, till my specimens tempted me more narrowly to inspect and describe them. # % % “ That ore [of copper] which is most common is of a yellow brass-colour; # # Ht and, according to the quantity of the barren stone intermixed, sells from five to fifteen pounds per ton # & & . “ Of the green coppers, some are as light as a feather, being mere aerugo , or verdigris, some more solid and stony % % % . There is also a flaky kind of close contexture, sometimes cohering in tubes as it drops % ;/? # . “ I have likewise a blue earth of an extremely fine and small grit * # # . “ The grey ore is often prettily spotted with yellow and purple, but the more of this mixture the less is its value. When it is of an uniform lead colour throughout it is richest, and contains a great deal more metal than the yellow or green, being worth between fifty and sixty pounds per ton. “ Copper appears sometimes as a blue-black earth * % % . “ The red-ore mixed with glassy speckles (the crystallized salts of this metal) is called the fire-ore * ^ ^ . “ The most perfect copper, from which the before-mentioned are only so many inferiour and different removes, is the Malleable (from its purity called in Corn¬ wall the Virgin-ore) which, in small quantities at least, is found in all the most considerable copper-mines. A “ hopeful discovery ” in the Pool-mine was at twelve fathoms from the sur¬ face near the “ black-ore shaft.” “About sixty years since, some gentlemen of Bristol made it their business to inspect our mines more narrowly, and bought the copper raised at N’uun-vian in Piranuthno, and at Mr. Ustick’s works in St. Just for two pounds and ten shillings per ton, and scarce ever more than four pounds per ton. It must be observed that the yellow ore, which now sells for between ten and twenty pounds per ton, was at this time called poder (that is, dust) and thrown away as mundic. [Their] gains # % % encouraged other gentlemen, about forty years since, not only to buy copper at a low rate, but to engage as adventurers in some old mines; and at this time Mr. John Costar, a gentleman well skilled in metals, and par¬ ticularly knowing in mechanics and hydraulics, undertook % % % to drain some considerable mines : he taught the people of Cornwall also a better w/ay of assay¬ ing and dressing the ore. Here we may date the advance of the price of copper and improvement of copper-mines * * * . 688 W. J. Hen wood, on the Caradon of Western Cornwall; it was not until 1835—40, “ The first and greatest copper-mines which have turned out considerable profits within these forty years, are—Chace-water, in the parish of Kenwyn • North Downs, inReddruth; Huel-ros, in St. Agnes; Dalcooth, Bullen-garden, Entral, Longclose, Roskaer, and Huel-kitty, in Camborne ; Huel Fortune, in Ludgvan; the Pool, in Illogan ; Metal-works [United Mines] and Trejuvian, in Gwenap; Binner Downs and Clowance Downs, in Crowan ; Huel-cock and Rosmoran, in St. Just; and Herland mine in Gwinear. But the greatest and most sudden gain % % Ht was that of Huel-virgin, in Gwenap, in July and August, 1757. In the first fortnight’s working, it threw up copper sold for five thousand seven hundred pounds; in the next three weeks and two days, as much, copper as sold for nine thousand six hundred pounds : to raise the first-mentioned quantity, it cost the adventurers no more than one hundred pounds [less than four pence farthing in the Pound]; to raise the second, a trifle more in propor¬ tion to the quantity # # . The Lords dues are generally one-fifth part of the whole produce clear of all expence, never less than one-eighth clear & # Borlase, Natural History of Cornwall, pp. 168—9, 197—8, 205—6 ; PL XVIII, Fig 1. (— a) “About [1750] one Mr. Swaine built a furnace or two [near] the great Copper works in Camborne about half a mile north of the Churchtown in order to run the poorest copper ore (value 5 shillings pr ton) into a Regulus, aiming at nothing farther: for this purpose he brought all his Pitcoal on horseback from Heyl cellars near seven miles off * *• *■ . This humble plan [was] pursued with success for some years.” Borlase, Natural History of Cornwall (Emendations and additions by the Author, in preparation for a Second Edition. From a copy in the possession of Frederick Martin Williams, Esq., M.P., F.G.S., of Goonvrea). Journal of the Royal Institution of Cormoall, I. (1865), Supplement, p. 32. (5) “ Though the richness of our Copper works is not a late discovery, yet it is not a hundred years that the knowledge of working them to good effect hath been understood # # # . “Native copper is frequently found in our mines, near the surface, or com¬ monly but a few fathoms deep * * * . “ Wherever Copper is found, there is always green or blue Vitriol * * * . “The Stalactitical, is generally of a brassy colour; and so is the blistered buttony Ore * * * . Filagree, Laced, Machacada Copper, is the precipitation of Copper on the laminae of Gossan * * * . “ Green Copper Ore is very rare in Cornwall. Blue Copper is seldom met with. “ Gray Copper Ore is one of the richest sorts in this county; and will produce the greatest quantity of Metal, of any Copper Ore. Gray Ores are generally the heaviest of all ; * * * they must be dressed by sorting and sizing them, &c. “ Black Copper Ore, of a bluish-black, is also very rich. This is either solid or sandy * * * . It is so light, that it will not bear the usual dressing by water ; District in East Cornwall 689 that copper was successfully worked on both the but is generally griddled out and put to the pile for sale, as it rises from the Mine. Being in this condition, it partakes of Mundick, Gossan, Earth, and Crystal, so largely, that the intrinsick value of the Ore will be carried off with it. It. is said, that formerly several thousand pounds worth of this Ore was thus washed into the rivers, and discharged into the sea from the old Pool Mine. This kind of Ore in the Lode is oftentimes so fair, that it may be raised and dressed fit for smelting at the rate of a shilling out of the pound, in the price it sells for ; nay # % % many score tons [were] raised out of North Downs Mine at tenpence. This Ore generally lies shallow; and seventy years ago, when copper was not searched for and little known amongst us, the Tinners threw it into the rivers as refuse, by the name of Poder,« which signifies dust, Mundic, or waste. After it became well known, and was wrought for sale, it seldom ex¬ ceeded £3 : 10s. : 0 d. per ton for several years, while there were but one or two purchasers. “ Of yellow Copper Ore I have observed four sorts. The first is found shallow among black Ore, % % % and it can be scraped'into yellow dust of a rich ap¬ pearance. The second is fine gold coloured flakey Ore, * % % [worth] from £12 to £15 per ton * *- *. The third is a perfect brass coloured Ore, and is reckoned the best colour of any for its continuance in the Mine: # # * al¬ though the value may be not more than from £7 to £10 per ton # % #. The fourth and deeper Copper Ore is of a pale yellow, pretty much corrupted with Mundick, and of an inferior price, being from £4 to £6 per ton. # # % “ Even burnt leavings of Tin are often considerably valuable, especially if they are cupreous; and even the poorest bring ten or twenty shillings per ton. All burnt leavings, till the year 1735, were esteemed good for nothing. But in that year Mr. Morgan Bevan an old experienced assayer [having] assayed a sample of three tons found, to his surprise, that he could give seven pounds four shillings and sixpence per ton for them; and presently after he bought several parcels more of the principal Tin dressers. From that time burnt a “ The refuse and leavings from the stamping-mills, &c., which are carried by the streams down to lower grounds, and after some years lying, necessary to consume the mixture of bad metal, and poder (as they call it), viz. mundick, copper, &c. yield very good profit to the adventurers.”— Tonkin, Parochial History (Carew, Survey of Cornwall, Edited by Lord De Dunstanville), p. 28. “ In dressing of leavings of tin * * # the slime being compounded of the lighter parts of the ore intimately mixed a greater quantity of earth and stones, bruised to dust by the mill, is * * # [set] on one side until the water leaks away and leaves it to dry exposed to the sun and air [which act as menstrua], consuming, or rather dissolving the Poder, that is the Mundick, particles of Copper, and other trash. Then it is digged and broken to pieces * * # when it is trunked and framed # # # — Pryce, Mineralogia Cornubiensis, p. 226. “ The sprinklings of copper which frequently occurred in the tin mines were considered as a species of yellow marcasite, or mundic, and was called Poder # * #. The interest of those who first discovered this mineral * * * to be copper-ore, made it for some time to be kept a profound secret, so that the precise time [of the discovery] is not ascertained; but it is believed to have been about the beginning of the last century.” Michele, Manual of Mineralogy, p. 40. 5 c 690 W. J. Henwood, on the Caradon northern and southern slopes of Caradon. Since that leavings, impregnated with copper, were taken much care of # % % . When the Brass-wire Company carried on the great Tin Mine of Chacewater,before this discovery they cast away some hundred tons of burnt leavings, to their great prejudice; but since that time there have been large quantities sold from the same mine. * * * “ About fifty years back great quantities of Copper Ore were risen from Huel Fortune in Ludgvan, Roskear in Camborne and Pool Adit in Illugan; the pro¬ duce of which Mines were sold to the few buyers at their own price, % * # till they were interrupted by a gentleman from Wales * % Ht , who bought at the advanced price of six pounds and five shillings per ton, fourteen hundred tons of Copper Ore, which had been lying unsold for some years at Roskear and Huel- Kitty, and for which the confederated buyers would give only four pounds and five shillings # # & . This new comer bought nine hundred tons more at Roskear at seven pounds per ton; and in six months # % # he purchased three thousand tons.”— Pryce, Mineralogia Cornubiensis, pp. 61—3, 192, 226, —30,—7,—86—7. (Abridged.) (6) “A century ago amongst the miners of Cornwall, whatever was not tin was heedlessly thrown aside ; and within that period, on the discovery of copper beneath the tin, it was no uncommon observation that the 1 ore came in and spoilt it.’ It is an undoubted fact that many roads in the county were mended with copper ore.”— Phillips (W.), Geol. Trans. (1814), ii. p. 141. (7) “ At the commencement of the last century, when yellow ore or pyrites had been long appreciated, the far more valuable redruthite, or sulphide of cop¬ per was thrown as worthless rubbish over the cliffs of St. Just into the Atlantic.” Smyth, Introductory Lecture to the course of Mineralogy and Mining , at the Museum of Practical Geology (1852), p. 10. Although other writers have treated of this subject, their statements differ so slightly from those already given, that it seems unnecessary to quote them.” The following particulars—collected from many books and extracted from several Registers—supply some means of judging, whether the principal writers on early copper-mining in Cornwall, were eye-witnesses of the matters they have described, or have founded their statements on other evidence. Richard Carew, Esq., was born at Antony in 1555, and died there in 1620. His “ Survey of Cornwall ” was published in 1602, but appears to have been in private circulation previously. William Hals, Esq., was born at Tresawsen in Merther, in 1653, and died at Saint Wenn in 1737. His “ Collections for a Parochial History of Cornwall ” were commenced about 1685 and brought down to 1736. Thomas Tonkin, Esq., M.P., was born at Trevaunance, St. Agnes, in 1678, and died at Pol Gorran, Gorran, in 1742. His “ Notes, illustrative of the History and Antiquities of Cornwall ,” were commenced in 1702 and continued till 1742. 691 District in East Cornwall. time, however, many mines have been opened there The Reverend William Borlase, LL.D., F.R.S., was born at Pendeen, St. Just., in 1695, and died at Ludgvan in 1772. In 1722 he was instituted to the Rectory of Ludgvan, and in 1732 he was presented to the Vicarage of St. Just. His “ Natural History of Cornwall ” was published in 1758. [The Mining Academy of Chemnitz, in Lower Hungary, was established in 1760; that of Freiberg, in Saxony, was opened in 1767.] William Pryce, Esq,, M.D., was born about 1720—30, and died at Redruth in 1790. His “ Mineralogia Cornubiensis ”— commenced about 1751-5 — was pub¬ lished in 1778. William Phillips, Esq., F.L.S., F.G.S., was born in London in 1773, and died there in 1828. His Memoir “ On the Veins of Cornwall,” —commenced in 1800—was pub¬ lished (Geol. Trans., n.J in 1814. John Taylor, Esq,, F.R.S., F.G.S., was born at Norwich in 1779, and died in London in 1863. His article on Mining was published in Rees’s Cyclopedia, xxiii. (1819). John Michell, Esq., was born at Calenick, Kenwyn, in 1773, and died there in 1868. His “ Manual of Mineralogy ” was published at Truro in 1825. Sir Henry Thomas De la Beche, C.B., F.R.S., F.G.S., Director of the Ordnance Geological Survey, was born in London in 1796, and died there in 1855. His “ Report on the Geology of Cornwall , Devon , and West Somerset ” was published in 1839. Warington Wilkinson Smyth, Esq., M.A., F.R.S., V.P.G.S., is now (1869) Lecturer on Mining and Mineralogy at the Royal School of Mines ; and Inspector of the Mineral Property of the Crown and the Duchy of Cornwall. His Lecture “ On the Value of an extended knowledge of Mineralogy and the Processes of Mining , was delivered in 1852. It may not be out of place to recapitulate that D. Borlase') (Yellow copper-ore) (to have been) (Black & vitreous ore 1 I C3 1 I j “ (_ Black Vitreous f 1 thrown away as f ) yellow & yitreous n rubbish; but is ( J silent as to ..) ( Yellow & black (havingbeen ) treated in j the same manner. Dr. Pryce Mr. Smyth. Now— Dr. Borlase was born in 1695, and in 1758 he wrote that “ about sixty years earlier yellow ore was thrown away; ” it is manifest, therefore, that when such waste took place, he (the future writer) was yet in his childhood;— Dr. Pryce — whose birth took place about 1720-1730 — stated in 1778 that “ seventy years before the Tinners threw black-ore into the brooks as refuse;” a comparison of dates proves that period of ignorance to have existed when he (who has perpetuated the remembrance of it) was as yet unborn; even the sepa¬ ration of copper from calcined matter, which had been already treated for the 692 W. J. Henwood, on the Caradon and in the neighbourhood, and some of them have tin-ore it contained, seems to have first taken place in 1735, during his infancy; — and Mr. Smyth (an occasional, though now a frequent, visitor to the neighbour¬ hood)—speaking, in 1852, more than one hundred years after the event he de¬ scribes—says “ at the commencement of the last century Redruthite (vitreous- copper) was thrown as worthless rubbish over the cliffs of St. Just into the Atlantic;” at that time, however, Mr. (afterwards Dr.) Borlase—a native of the parish—resided on or near the spot. Mr. Phillips—who was born in 1773—recorded it in 1814 as “ an undoubted fact that Hi Hi Hi within a century Ht Hi Hi many roads in the county were mended with copper-ore;” the event being thus—in another instance—sup¬ posed to have taken place before the birth of the describer. These several writers, therefore, record— differences (though perhaps | ag periods of misappropriation;— immaterial ones) j ^ r ,, ,, in the natures of the ores misappropriated;—and ,, ,, ,, modes of their misappropriation ; nor is it surprizing that accounts should so materially differ, when given so long after the events, by parties who could not have been eye-witnesses. But the early progress of copper-mining in Cornwall had not escaped the notice of contemporary authors ;—for— Mr. Carew states that [not later than 1602] he had visited a copper-mine, the produce of which shipped to Wales for reduction. Mr. Hals—who lived from 1653 to 1737,—and Mr. Tonkin—who was born in 1678 and died in 1742—state that, between 1673 and 1736, the yellow, ash- coloured (grey), earthy-black, and other—less abundant—ores of copper had been—not only recognized—but largely and profitably wrought, both in the eastern and western parts of the county. It appears, therefore, that Dr. Borlase, in 1758, sixty, and Dr. Pryce, in 1778, seventy, years after the events,—which, in fact, must have happened in the child¬ hood of one and during the infancy, if not before the birth, of the other,— represented the workmen, in 1698 and 1708, to have rejected, as worthless, two rich ores of copper; whilst, in 1852, Mr. Smyth reported a third valuable copper- ore to have been—at the commencement of the last century—cast into the sea. Whereas Mr. Hals and Mr. Tonkin, the latter himself a mine-owner—who lived (and wrote from 1685 to 1733) before, during, and after the periods when, it was (subsequently) said, such ores were “ thrown away ”—mention the mines then worked in different parts of Cornwall, and describe the nature of their produce, but both are—as (in 1586—1602) their predecessor Mr. Carew had been—silent on the subject of waste. The circumstance—mentioned by Mr. Taylor—that seven hundred tons of English copper were coined at the mint in 1717, bears directly on this question. In reference to the statement that copper-ore had, within a century, been used as road-metal; it must be remembered that all lodes partake, more or less, the nature District in East Cornwall . 693 been amongst the most productive in the county: of the adjoining rocks, and thus consist, in great measure, of earthy minerals.a Of the principal Cornish vein-stones and ores the comparative hardness is,— quartz 7', felspar 6*—6*5, hornblende 5*—6’, fluor 4’, chlorite 2*—2-5, oxide of tin 6 f —7’, iron-pyrites 6’—6’5, copper-pprites 3 '5 —4*, vitreous-copper 2’5—3*, black copper-ore usually occurs in an earthy state. The ores of copper are therefore both softer and less plentiful than the ordinary vein-stones. Thus all later writers concur in stating much waste to have taken place at the commencement of copper-mining in Cornwall, but they differ as to the kind of ore wasted, and on the mode of the waste; whereas earlier authors are, to a man, silent on the subject. The following different accounts of the same circumstance may not be irrele¬ vant here. % “ Even within these few’ days a case has occurred in Devonshire W'here a field wall was constructed of grey copper ore, and the breaking of a gate post led to a knowledge of the fact. This happened in a mining district.” De la Beche, Inaugural Discourse at the opening of the Government School of Mines, 6th November, 1851, p. 10, Note. “ The stuff brought together, at the spot mentioned, from walls, gate-post, pits, &c., by mining and all other means, was but a few tons; and after the best manipulation—even at a high Standard—it Avas unsaleable.” Joseph Matthews, Esq., Purser of Wheal Friendship, near Tavistock, MSS. Dr. Pryce states that owing to negligence in (dressing) preparing earthy black copper-ore for the market several thousand pounds worth of it had been washed into the rivers and discharged into the [Bristol channel] north sea. As long as the lodes were wrought underhand b —in fact until 1778-1815,— the water which entered most of, if not all, the shallower works, found its way over the working-stores (steps), to the bottom of the mine. The present system, of levels and winzes, —by gradually draining the lode whilst laying it open for (back-stopeing )e —prevents, in great measure, the percolation of water through broken ore. But even now, when earthy black copper-ore is wrought—as it was a “ Upon an average for the last ten years (1768—1773) one hundred and fifty thousand tons of rough Lodes hare yielded about twenty-four thousand tons (0 - 16 its weight) of merchantable copper ore.”— Pryce, Mineralogia Cornubiensis, p. 186. “ Quant au poids totaux des matieres extraites, on sera au-dessous de la realite en prenant pour chaque tonne de minerai prepare, pret a vendre : 50 tonnes extraites des mines d’etain ; 3 ,, „ de cuivre; 82 „ „ de plomb.” Moissenet, Annates des Mines, 6me Serie, n. p.252. b Borlase, Nat. Hist, of Cornwall, p. 169, PI. XVIII. Came, Cornwall Oeol. Trans, in. pp. 68—9. Ante, pp. 645—6, Sub-note. c Came, Cornwall Geol, Trans., ill. pp. 67r-72. Ante, pp. 645—6, Sub-note. i 694 W. J. Henwood, on the Caradon thus— South Caradon, between the 1st of Jan., 1836,) a * * * * § and the 30th of June! 1868 ; | afforded a profit of £315,605;* West Caradon, . from 1840 to 1868, ,, about 110,000, t + Marke Valley ., 1840 „ 1868, „ ,, 50,000. § , Many other mines || have been wrought within the at Wheal Jewels during 1829-31—in a “ wet Country ,” the “ weepings ” of the ends, walls, and backs accumulate in the levels, flow to the shafts, and are raised through the pumps; bearing with them, in suspension, finer and softer portions of the mineral; which either subside and are recovered (occasionally in recep¬ tacles prepared for arresting them) in the adit, or pass off in the stream and are lost. Such loss, however, is by no means owing to ignorance of the nature and value of the ore lost; but—like the loss of tin-ore in Cornwall, b and of gold (where the vein-stones are stamped j in Brazil c —is due to the, insufficient, means hitherto adopted for intercepting it. * South Caradon , from the 1st of January, 1836, to the 30th of » co- June, 1868, afforded ores which realized ) * ’ the working expenses (salaries, wages, tools, &c.) 1 „ 750 0 fi 7 during the same period amounted to . ) A ’ Royalties (Dues J . 62,923 Profits. 315,605 - £1,128,595 W. H. Rule, Esq., Purser and^ Accountant of the Mine, MSS. Ante, p. 457; Table XIV. f Allen, History of Liskeard, pp. 396, 420. Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District , pp. 34—6, 92—3. Captain William Johns, Manager of West Caradon , MSS. J “ A striking increase in the value of property occurred with respect to Down¬ hill, a small coarse tenement in St. Cleer, which had been purchased thirty years before for £200 * * * . By the discovery of mineral lodes, and the opening of West Caradon Copper Mine in this barren spot, the proprietors have received for the last twelve years, without any risk, an income of more than £2,000 a year, as dues on the ore. The landowner of South Caradon, an equally barren sur¬ face, has benefitted to a still greater extent.” Allen, History of Liskeard, p. 397. Ante , p. 353. § Captain John Truscott, Manager of Marke Valley , MSS, || In 1862, j East Caradon had already given Craddock Moor „ “ l * 37 ' 970 ^; a Fox, Phil. Trans., cxl. (1830) p. 401. Henwood, Cornwall Oeol. Trans., v. Table LX V. b Ante, p. 354, Note j c Ibid, pp. 354—5. District in East Cornwall. 695 district, and in its neighbourhood ; but the writer has not examined them. Pebbles of stream-tin ore are, from time to time, still found, amongst the rubbish, on either side of an ancient opening # which extends, from near the Hurlers,')' northward to Withy-brook marsh.J The low lands traversed by greenstones are ex¬ ceedingly fertile; but the thin covering of slate, which overlies the granite, affords an ungrateful soil. Undulating moors and impassable swamps occupy ■whilst in Caradon Consols . Caradon Hill .. East Wheal Agar . Gonamena . Great Caradon . New South Caradon . North Phoenix . South Caradon Wheal Hooper .. South Phoenix . West Rose Down . West Sharp Tor . . . Wheal Caradon . Wheal Norris ... Wheal Pollard . £22,712 1,843 11,424 20,121 7,782 3,000 1,100 14,221 35,172 5,875 36,608 5,400 15,175 15,000 •►£195,433 had been expended. Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District , pp. 7, 9. * De la Beche, Ordnance Geological Maps , Sheet xxv. Whitley, Geological Map of the Caradon Mining District. Symons, Plan of the Caradon Mining District. + Borlase, Antiquities , Historical and Monumental , of the County of Cornwall, p. 199, PL XVII., Fig. 6. t “ On the west side of the Cheesewring a small stream, a mere rivulet, finds its way along a valley extending northward into the moors of Altarnun and Northill; and there are numerous evidences of its. course having been worked for tin—probably at periods far apart.” Blight, Journal of the Royal Institution of Cornwall , in. (No. ix.) p. 13. 696 W. J. Henwood, on the Caradon great part of the granitic region.* Caradon, Sharp Tor, and the picturesque rocks of the Cheese-wring,f * “ The granite of this district # * % throughout its whole extent is one expanded scene of sterility and desolation: trees there are none; and it is only in favoured spots, that vegetation has attained even to the size of a furze-bush. The elevated situation of this granitic land, exposed to every blast from the ocean, is, without doubt, unpropitious to the growth of trees and shrubs: but a more powerful cause is to be found in the nature of the mass that results from the decomposition of the granite. The grains of quartz render the granitic soil gravelly and easily permeable to water; so that, in all inclined situations, the rain washes away the fine particles of light clay that have been produced by the decay of the felspar; thus rendering the soil less adapted for vegetation, and not sufficiently tenacious to give a firm support to trees. % % % All the hills are crowned, and covered on their precipitous sides with immense hoary blocks of granite, which are generally heaped upon each other in the most fantastic forms. # Ht # The bottoms of all the valleys are covered with bogs, which are some¬ times so extensive and deep, and have such long and winding branches, that, even in fine weather, it is difficult for a stranger to extricate himself, when once entangled in their mazes. In many places, the bog is more than a dozen feet in depth: the bottom layers of which, afford a good peat, not inferior to that of Ireland.”— Boase, Cornwall Geol. Trans., it. p. 170. f In course of the Trigonometrical Survey “ Caraton Hill ” was ascertained to be ... 1,208 feet above the level of the sea. During the Geological Survey “ Sharp Point Tor ” was found to be .... De la Beche, Report on the Geology of Cornwall , Devon , and West Somerset , pp. 14, 18. “ The Bock now called Wringcheese attracts the admiration of all Travellers. $ * % The upperstone was, as I have been informed, a Logan or Rocking- stone, and might, when it was entire, be easily moved with a pole; but part of it has been broken off, and that weight which kept it on poise is taken away. The whole heap of stone is 32 feet high; the great weight of the upper part, and the slenderness of the under part makes every one wonder how such an ill-grounded pile could resist for so many ages the storms of such an exposed situation. # % * There are several heaps of Stones on the same hill, and also on a hill about a mile distant, called Kell-mar’r, of like fabrick though not near so high as this,” Borlase, Antiquities of Cornwall (Second Edition), p. 173, PI. XII. Fig . 1. “ This remarkable cairn consists of five stones, of which the upper ones are so much the largest as to overhang the base on all sides. The collective height of the whole pile is about 15 feet.” Mac Culloch, Geol. Trans., n. p. 70, PI. IV. “ This remarkable mass of rocks, eight or ten in number, is about 22 feet in 1,200 >> District in East Cornwall 697 i however, attain an elevation of twelve hundred feet, and command a prospect of great extent, variety, and beauty.* * The following columns show the produce of the several copper-mines described, and the numbers of work-people employed, as well as the power of the steam and water machinery in use, at each of them respectively, during the year 1851. height; at the broadest place near the top about thirty-four feet in diameter; and at the narrowest part of the base about 17 feet.” Parochial History of Cormcall (Truro, 1869), hi. p. 3 32. Hitchins & Drew, History of Cornwall , i. p. 144; n. p. 420. Lysons, Corn¬ wall , p. clxxxiy. C. S. Gilbert, Historical Survey of Cormcall , I. p. 172; n. p. 479. Bond, History of Looe, p. 204. * “ The views from Sharp-Tor are truly sublime. The spot is nearly the centre of the broadest part of the County; from it we saw both seas, north and south, and consequently the intervening land, # & * . We also saw in the north sea a very high land, which we concluded must be Lundy island; # % % . The prospect was equally extensive east and west. We discovered Launceston castle, % % % and we were much struck with the beautiful and highly cultivated lands to the east, terminated in part by the high lands of Dartmoor. To the westward nothing was to be seen but a vast continuance of moor land, without a hedge, without a tree, for a stretch of many miles. The extreme point of our western view, dimmed by distance, showed us Roach rock, and we also saw Dosmerry about four or five miles off; our south view commanded Plymouth- sound, and a long extent of coast and sea.” Bond, History of Looe, pp. 208—9. “ The scene from the Cheesewring, at an elevation of upwards of twelve hundred feet, is of a most imposing character. To the west all is rough and wild, a large succession of hills with Brown Willy and Rough Tor from their height and broken surface forcing themselves into foremost attention. Here the stern grandeur of the moor is seen to perfection. Looking south the prospect is more pleasing. Immediately beneath us are the granite works, with their cone¬ like heap of rubble; and just beyond, occupying twenty acres of ground, is a row of cottages with gardens occupied by the quarrymen. Further on are the Caradon and Phoenix mines ; and then commences that fertile and well-wooded district between Liskeard and Looe, the sea forming the horizon. The coast of the English Channel is to be seen from Rame Head to Fowey; turning to the east Kithill and Dartmoor come into the view; % # % and towards the north Hartland Point and Barnstable Bay—some thirty or forty miles off [are plainly seen.] ”— Western Daily Mercury , xv. (No. 2,463, 28th May, 1868), p. 2. Copper-ore obtained, Population employed, and Machinery in use, at the princij^al Mines in the Caradon District, during the year 1851. 698 W. J. Henwood, on the Mines of * Hunt, Records of the School of Mines, i. p. 447. d. Double-acting engines, s. Single-acting engines, c. Combined (Hornblower’s) engines . Menheniot, Lanreath, and Saint Pinnock. 699 Lead-mines have been wrought to great depth, extent, and advantage in Menheniot some two miles and a half N.N.E., as well as in Lanreath and Saint Pinnock three miles and a half S.W., of Liskeard.* * * § The Menheniot District extends from Butterdon, near the Liskeard and Calling- ton turnpike (about two miles and a half S.E. of the Caradon granite f) S., to within half-a-mile of the church; a tract, perhaps a mile and a half in length, but nowhere exceeding two furlongs in width. Hitherto the only productive part of The Lanreath and Saint Pinnock District has been an area of scarcely a mile long or a furlong wide, near the confluence of several rivulets with the Duloe J brook at Herod’s-foot.^ As the characters of the rocks, lodes , and cross- * “ Herod’s-foot is situated in the boundary of the parishes of St. Pinnock and Lanreath, about seven miles S.W. of Caradon; Trelawny in Menheniot > from four to five miles E. of that hill.” Giles, Cornwall Geol. Trans., vn. p. 201. “ The lead mining district in the neighbourhood of Liskeard % % % is rather scattered, extending in the killas in a zone about 8 miles long, from 4 miles E.N.E of Liskeard to about the same distance S.W. of that town, flanking on the south of the Caradon granite at a distance varying from 2\ to 5 miles.” Salmon, Mining and Smelting Magazine, n. p. 211. t Ordnance Geological Maps , Sheet xxv. Ante, p. 656, X u The Duloe rises at Broadoak Common, St. Pinnock, and joins the Looe near its mouth .”—Pick and Gad (1857), p. 6. § “ Herod’s-foot, the oldest mining work in the neighbourhood of Liskeard, is rather curiously situated at the confluence of four steep valleys, through the principal of which the river Duloe flows nearly due north and south to its junc¬ tion with the Looe.”— Salmon, Mining and Smelting Magazine , it. p. 211. 700 W. J. Henwood, on the Lead-Mines of veins , and the relations they severally bear to one another, are—with a single exception—much the same in Menheniot as in the Lanreath and Saint Pinnock district, it may be convenient to consider them at the same time. ( a ) The rocks in both districts consist mostly of slates ; generally greenish, brown, drab, or dun-colour¬ ed near the surface, but homogeneous, of silky lustre, and of deep-blue or blackish hue at greater depths. Certain nests of pulverulent ferruginous matter (? of organic origin) interlie the slates in a shallow quarry near the boundary between Wheal Trelawny and Wheal Mary Ann;* and similar bodies, as well as Crinoideal remains, occur on the way-side near Herod’s-foot * * “ At Roseland # % % organisms are very numerous, though generally in a broken imperfect condition; they consist of Trilobites , Orihocerites, Bellero- phons, Turbinolopses. Pleurodictya problematical and Crinoidea, besides other forms which I have not been able to identify. % % % “ At Stoney-bridge % # % two or three examinations rewarded me with several portions of Trilobites and some Turbinolopses , and also what I take to be a Spirifer, % % # “ At Trussil-bridge the fossils are, if not exclusively, yet mostly found in certain thin strata here and there along the succession of the beds? but the strata in which the organic remains most abound differ from the general sample in being softer and more ferruginous.” Giles, Cornwall Geol. Trans., vn. (1849—51), pp. 94—5, 97, 170. “ I could trace Crinoidea , <§rc. in the slates, all the w r ay from Lamellion by Herod’s Foot, Berry Down, and Lanreath, to St. Veep.” Peach, Cornwall Geol. Trans., vlr. (1849), p. 104. “ The beds near Liskeard are considerably lower [than the Plymouth lime¬ stone] in the series of deposits ; and it was not without hesitation that I desig¬ nated them by the distinctive name of Liskeard Group. They are certainly neither Silurian nor Cambrian, and may be regarded as a lower subdivision of the Great Plymouth Group. % % % A very old Devonian group with many fossils, collected and partly described by Mr. Giles and Mr. Peach, exists in the neighbourhood of Liskeard.”— Sedgwick, Quarterly Journal of the Geol. Soc., Menheniot , hanreath, and Saint Pinnock. 701 At different depths, on one side or other, and occa¬ sionally on both sides, of the lode , in various parts of its range through Wheal Trelawny * * * * § and Wheal Mary Ann,f as well as, in one part at least, adjoining the flucan in the latter, the ordinary homogeneous clay- slate is interlaid by conformable beds and isolated bodies of felspathic and hornblendic rocks £ (locally known as JElvans §); mostly of massive, but here and viii. (1852), pp. 5, 17, 146 ; British Paleozoic Rocks (Introduction, 1855), pp. XXIII. “ The beds which dip into the synclinal area of Liskeard, and undulate thence to Saltash and St. Stephen’s represent in less force the higher group of David- stow and Lewannick. Folded in among this upper group are some slate-beds locally fossiliferous, as at the Tregril slate-quarry, at Great Tressell north of St. ELeyne, Doubleboys, Stoney Bridge, near Liskeard, and in the cuttings of the railway south of that town, and likewise at Saltash and St. Stephen’s. Among these fossils we find noticed Pleurodictyum problematical, Atrypa desquamata, Bellerophon bisulcatus, Fenestrellaantiqua , an Orthoceras, two species of Spirifera , some undetermined CycUhophyillidce, Phacops latifrons , and P. punctatus . The last species was found at Great Tressell by Mr. Pengelly, and is a characteristic Middle-Devonian fossil.” Hole, Quarterly Journal of the Geol. Society , xxiv. (1868), p. 423. * Table XXVII. f Table XXVIII. J “ Near Tregerla slate-quarry, the hornblende rock of St. Clere Down, and the same in a state of decomposition, occur in great abundance.” Rogers, Cornwall Geol. Trans., n. p. 221. “ From Hessen Ford to Quethiock a mixture of arenaceous beds and argilla¬ ceous slates [is] traversed, among which we find a great variety of trappean rocks, some of them possessing the schistose character, # % % the compact kinds are generally greenstones.”— De la Beciie, Report on the Geology of Cornwall, Devon, and West Somerset , p. 79. § “ Near the north and south lead lodes [the rocks locally] called elvan consists chiefly either of soft felspar, with more or less of hornblende matter, or of a kind intermediate between the common grey elvan aud magnesian greenstone. % % % They do not occur in regular dykes or courses ^excepting in one in¬ stance) but in floors, and in numerous small detached masses, called by the miners bunches. Many of these appear to be completely isolated; for instance, several masses of this description occurred in the Trelawny shaft so entirely surrounded by killas, as to exhibit slate in all the four corners. But the more general mode of the connexion of the elvan with the lode is in floors , of varying, / 702 W. J. Hen wood, on the Lead-Mines of there of schistose,* * structure. Between these and the slate a gradual transition sometimes takes place; but usually the passage from one to the other is distinct and immediate. They are probably connected with one or other of several similar masses, shown on the Ordnance Geological Map ; f in one of which—at Lambest—spheroidal bodies, made up of many con¬ centric layers,J are imbedded in a basis of identical composition. Nor is this concretionary structure peculiar to the felspathic and hornblendic rocks, for one side (wall) of the lode , at a depth of fifty-five fathoms, in Wheal Trelawny § presents a section of a spheroidal con¬ cretion {Fig. 32), presenting a nucleus and an external envelope of galena separated by four several layers of quartz, each distinguishable, from either of the layers adjoining it, by some peculiarity of structure or of hue. This remarkable body was found imbedded in quartz transfused with slaty matter, which gradually shaded into the ordinary deep-blue (Country) slate. but never of very great, thickness. Their underlie is not conformable to the dip of the slates, but inclines in different directions. Ht Ht Hi In the southern part of Wheal Mary Ann an elvan of a more dyke-like character occurs; Hi Hi Ht but its dip and bearing are alike unknown, although, as nearly as can be judged, [it seems to] dip about S.E.” Giles, Cornwall Geol. Trans., vn. pp. 201,— 5, —6. (Abridged.) * “ From Pengover to Clicker Tor the Hi % y; rock exposed is hornblende slate.”— Boase, Cornwall Geol. Trans., iv. p. 211. f Sheet xxv. X “ It is not improbable that the spheroidal forms so commonly exhibited by the crystalline rocks, are varieties of original structure, the result of some pe¬ culiar mode in which their integrant particles have been aggregated together, and which appear to subsist in the same mass, in conjunction with various euboidal and prismatic arrangements.”— Boase, Primary Geology,Tp. 97. $ Table XXVII, column 5. Menheniot , Lanreath, and Saint Pinnock. 703 Fig. 32. WHEAL TRELAWNY, East Cornwall. Section of a concretion in the (Country) slate. (Scale one-fourth of the natural size.) 1. Galena. 2. Quartz; translucent, of slightly radiated structure. 3. „ : milk-white, „ „ „ 4. „ ; translucent, „ „ „ 5. „ ; yellowish, containing cavities lined with minute crystals of translucent quartz. 6. Galena. In both districts the planes of cleavage range from E.-W. to N.E.—S.W., and dip 5°— 15° S.—S.E.; in short, occasional, flexures, however, they sometimes decline slightly towards the N.—N.W. The best developed and most numerous of the joints —maintaining in both cases a general parallelism with the lodes —bear from 8° E. of N.—W. of S. # to 12° W. of N.—E. of S.f Many joints range ,, 25° # —45 °% E. of N.—W. of S , as well as „ 18°J— 35 ° # W. of N.—E. of S., and others take yet different directions.^ * Table XXVIII. f “ In 1840 the magnetic declination was 25° W.” Sabine, Phil. Trans ., cxxxix. p. 205, PI. XIV. Ante, p. 673. + Table XXIX. § De la Beche, Report on the Geology of Cornwall , Devon , and West Somerset , p.273. Ante, p. 673, Note * * * § , 704 W. J. Hen wood, on the Lead-Mines of ( h ) Both districts have been carefully examined ; but in neither of them has more than one lode* * * § yet been found productive. (—1) The lode in the mines of Menheniotf J takes slightly different directions in different parts of its course; thus in Wheal Trelawny it bears about 5° W. of N.—E. of S.; but in Wheal Mary Ann „ 3°—8° E. of N.—W. of S.; whilst in the Lanreath and Saint Pinnock district,J the lode at Herod's-foot bears, generally, 8°—12° W. of N.—E. of S. (—2) The lodes of the entire region maintain an average underlie of 79°; yet in one of them certain portions dip only 64°, and in the other but 70°; of both, however, large parts are nearly vertical. Their general inclination is to the E.; § but—as well in one * Henwood, Reports of the Royal Institution of Cornwall , xxxm. (1851), p. 39. Giles, Cornwall Geol. Trans., vn. (1852), pp. 201,—3. Allen, History of Liskeard, p. 421. Salmon, Mining and Smelting Magazine , ii, (1862), pp. 215, —18. Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District, pp. 17, 26, 37. t “ Wheal Trelawny, Wheal Trehane, and Wheal Mary Ann contain but one lode [which bears] about north and south.” Henwood, Reports of the Royal Institution of Cornwall, xxxin. p. 40. In Wheat Mai) Ann j £ the lode is 24° or 25° west of south [magnetic], the general bearing $ l o j In Wheal Trelawny) is from 19° to 24° east of north ,, .” the average bearing $ ” ” Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District , pp. 27, 37. t “ In the Herod’s-foot and Trelawny mines the vein * # % bears from 20° to 27° E. of N. [magnetic].”— Giles, Cormoall Geol. Trans., vn. pp. 301—2. “ The lodes which produce lead-ore in a zone # % from 4 miles E.N.E. of Liskeard to about the same distance S.W. of that town % # $’t have an approximate bearing of north and south.” Salmon, Mining and Smelting Magazine , ir. p. 211. § In the Caradon district every cross-course dips towards the W.— Ante, p, 682. Menheniot , Lanreath , Saint Pinnock. 705 as in the other—short flexures towards the W. occur at intervals. (3—) In width they vary from 0*5 foot to 4 feet; and average, perhaps, 2 feet; * but, occasionally, both are made up of many subordinate veins. (—4) Of both lodes the chief ingredient is quartz * Henwood, Reports of the Royal Institution of Cornwall, xxxiii. p. 40. Giles, Cornwall Geol. Transactions, vn. p. 203. Salmon, Mining and Smelting Magazine, it. p. 220. Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District, p. 17. 4 f “ In the N. part of Wheal Trelaicny the lode affords, near the surface, much earthy-brown iron-ore and granular quartz; the cavities (vughs) in which/ as well as the joints in the neighbouring (Country) rock, sometimes contain the carbonate of lead. At greater depths, galena, great quantities of iron-pyrites, and smaller proportions of blende, are imbedded in quartz that closely resembles hornstone. “ On either side of the boundary between Wheal Trelawny and Wheal Mary Ann, shallower portions of the lode still yield the carbonate—and occasionally also the phosphate—of lead; beneath, however, the quartz—especially towards the middle of the lode —is largely mixed with fluor, yet both contain galena, and both are drusy, but the lead-ore and the cavities occur more frequently in the fluor than in the quartz. “ In the S. part of Wheal Mary Ann fluor and quartz still make up the chief part of the lode. Occasionally, however, small hollows in the fluor are sprinkled with crystals of the same substance; and these—as well as massive portions of the sides—are frequently encrusted with white, greyish, or yellowish crystals of the sulphate of barytes, overlaid with crystallized iron-pyrites, or studded with small brilliant grains of galena, now and then in unusual crystalline forms; moreover both fluor and barytes—especially the fluor—are sometimes thinly powdered with minute double-pointed crystals of quartz. The fluor rests some¬ times on quartz, sometimes on galena; but the sulphate of barytes seldom but on fluor. Most of the rarer crystals, however, have been obtained at less than eighty fathoms deep. A peculiarity of this lode is, that even in its most pro¬ ductive parts, the ore occurs in small, unconnected, though rich bunches, rather than in one large and continuous, vein. In the midst of the fluor, indeed, and occasionally, though more rarely, in the quartz, cubic crystals of galena are isolated in the earthy ingredients. Whether the ore be massive or crystallized, quartz and fluor are the only matrices in which it cccurs; and the most perpen¬ dicular parts of the lode are always the most productive. “ The ordinary quartz, which forms the matrix of the lead-ore, frequently bears rectangular impressions; and the iron-pyrites exhibits here and there casts 706 W. J. Henwood, on the Lead-Mines of often granular and sometimes mixed with earthy brown iron-ore near the surface, bat generally massive and of milk-white hue beneath ; in the Menheniot lode , how¬ ever, it assumes the character of hornstone in some, of hexagonal pyramids; but of the substances by which they were impressed, all traces have disappeared.” Henwood, Reports of the Royal Institution of Cornwall , xxxm. (1851), pp. 40—3. (Abridged.) “ At Herod’s-foot the matrix mostly carrying the ore is saccharine-quartz* accompanied here and there by iron-pyrites. Antimony in small quantities is also disseminated through the lode, just below the gossan, and fortunately de¬ creases in the lower levels. Blende in still less quantities has been found. But a rich sulphuret of copper is occasionally found in bunches sufficiently large to make a mercantile commodity. These bunches often occur in parts of the lode which are richest in galena. “ The Trelawny lode * £ # wffiich is richest in its nearest approach to the perpendicular, % % ?c mostly [consists of] a whitish-brown fluor-spar, which contains the ore in a state of general dispersion. Many of the specimens of this mineral which are found on the walls of the fissure, are of various colours and beautifully crystallized in cubes. The beauty of some is enhanced by the presence of very large cubic crystals of galena. Others have small octangular crystals of galena scattered over the fluor. Next to fluor, hornspar is the most plentiful mineral. Small quantities of the carbonate of lead, both crystallized and in the massive state occur, but they are most plentiful in the shallower levels. A few years since a considerable quantity of the phosphate of lead was found just under the gossan, but the miners not placing much value upon it, suffered it to be thrown away with the rubbish : afterwards, if I remember correctly, some few tons of it were collected and sold. But perhaps the most interesting of all the extraneous minerals contained in this lode are the crystals of the sulphuret of barytes; which w r ere abundant to the depth of about forty fathoms, but below that point few have been discovered. # & # It is no uncommon circumstance to meet with slabs exhibiting a coating of pyramidal quartzose crystals over the faces of casts of decomposed minerals. The sulphuret of copper occurs in small quantities in different parts of the lode, and in the deeper parts is so com¬ mixed with the galena as to deteriorate some of the samples, although its occur¬ rence is generally coincident with an abundance of ore.” Giles, Cornwall Geol. Trans. , vn., pp. 202—5. (Abridged.) “ The lode, which in Wheal Mary Ann and Wheal Trelawny has been remark¬ able for its productiveness, is a large and strong one containing a great deal of fluor-spar and carbonate of lime, with capels generally on both sides.” Salmon, Mining and Smelting Magazine, n. p. 221. Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District , pp. 16, 26, 36. Menhenxot , Lanreath , and Saint Pinnock. 707 yet is associated with calcareous matter in other, of the deeper parts. Between th eflucans in Wheal Trelawny and Wheal Mary Ann , green, greenish-yellow, or light-brown fluor often prevails towards the middle of the lode; but—though frequently abundant—it is seldom, or never, the only vein-stone. White, greyish, or greenish crystals of the sulphate of barytes sprinkle the fluor in many small cavities, to a depth of perhaps eighty fathoms, where—in the S. of Wheal Mary Ann —both sides of the lode are bounded by rocks of fel¬ spar and hornblende. And, under similar circum¬ stances, crystals of quartz are studded with other minerals. At Herod's-foot joints in the rock and crevices in the lode are often encrusted with pearl-spar. Iron-pyrites—sometimes associated with silver—is a common ingredient in many, if not in most, parts of both lodes; but small quantities of copper-pyrites, and trifling proportions of blende, occur most frequently in,—if indeed they are not limited to,—the quartzose portions of their vein-stones. The sulphuret of anti¬ mony and bournonite are peculiar to the lode of Herod' s-foot. From amongst the earthy brown iron-ore and granu¬ lar quartz which abound in the shallower parts of both lodes , as well as from the joints of the contiguous rocks, small masses and minute crystals of the carbonate, and —less frequently—of the phosphate, of lead, have been obtained at intervals. These salts of lead — which occur near the surface only—are, at greater depths, succeeded by galena. In the Menheniot lode —under 708 W. J. Hen wood, on the Lead-Mines of certain conditions in the adjoining (Country) rock— quartz, fluor, and calcareous matter form a congenial matrix; the ore, however, is more plentiful towards the middle than near the (walls) sides; and appears more frequently in single granules, isolated blocks, and small (hunches) masses connected by thin veins, than in large (courses) bodies of endlong (shoot) dip. At Herod’s-foot, on the other hand, the granular quartzose vein-stone includes numberless small lumps, and is traversed by many thick ribs of ore. In both these—as in most, if not in all, other— districts the lead-ore obtained from different lodes , and indeed from different parts of the same lode , are un¬ equally argentiferous.* The following columns show the proportions of silver obtained from the galena wrought at distant parts of, and at various depths in, the Menheniot lode . Wheal Trelawny . 1851.t Depth 105 fathoms. 18564 1857.§ 1869.f Depth 210 fathoms. Highest Lowest Mean Mean Mean Highest Lowest Mean 0-001376 0-001035 0-001245 0*000966 0-001371 0 001516 0 001335 0*001401 * “ La galene contient toujours de l’argent, en proportion tres-variable, dans les differents filons d’une meme localite, et dans les diverses parties d’un meme filon.” — Uivot, Principes Generaux du traitement des Minerals Metalliques, ii. p. 10. f From data supplied by the kindness of Edward Michell, Esq., of Mitchell Hill, near Truro. $ Hunt, Memoirs of the Geological Survey of Great Britain (Mining Records for 1856), p. 29. Ante, p. 120. § Hunt, Memoirs of the Geological Survey of Great Britain (Mining Records for 1857), p. 31. Ante, p. 120. “ Where the galena is associated with copper, it contains an unusually large Menheniot , Lanreath , and Saint Pinnock. 709 Wheal Mary Ann . 1851.* * Depth 98 fathoms. 1856.f 1857.J Highest Lowest Mean Mean Mean 0-001545 0-001166 0-001349 0 001168 0-001897 1867.* Depth 256 fathoms. Highest 0-001400 Lowest 0-001224 Mean 0-001327 Thus, at Wheal Trelawny , th :S a a t rg a e tpth U o S f} «» ■*»** 0-001376 its weight of r oi silver. „ „ 210$ „ , „ 0-001516 At Wheal Mary Ann , on the contrary, «:. rg XTo s f. g . a ':?r | 98 ^ .. • „ „ 256$ „ , „ 0,001400 In both mines, however, the least argentiferous of the ore wrought at the greatest depths § gave larger proportions of silver than that found nearer the surface. The lead-ore extracted from different parts of the Herod' s-foot lode has afforded the undermentioned proportions of silver. Herod’s-foot. Old, or Northern, Mine. Depth 141 fathoms. 1851. Mean 0-000350 1856.| Mean 0-000359 New, or Southern, Mine. Depth 160 fathoms. 18574 Mean 0*000653 1867.IT Mean 0-001895 amount of silver. % % % In the hard killas the lode is smaller; but * % * it is here considerably richer in silver (containing from 13 to 17 ounces per ton more) than in any other part of the mine.” Giles, Cornwall Geol. Trans., vii. pp. 205— 6. * Ante, p. 708, Note t. f Ibid, Note J. j Ibid, Note § . § “ The substantial ore ground is entirely in the bottom of the mine.” Salmon, Mining and Smelting Magazine, ii. p. 218. || Salmon Mining and Smelting Magazine, ii. p. 214. IT Thomas Trevillion, Esq., Manager and Purser of the Mine, MS. 710 W. J. Henwood, on the Lead-Mines of Between the proportions of lead and silver, however, there seems no necessary connexion. # * “ La teneur en argent des gallenes est generalement trop faible pour qu’oxx puisse determiner par des moyens chimiques l’etat de combinaison du metal precieux; il existe probablement a l’etat de sulfure duns la galene.” Rivot, Principes GSneraux du traitement des Minerais Metalliques, II. p. 11. At Wheal Ludcott, on the confines of Menheniot, about a mile and a half N.N.E. of Wheal Trelavmy, the (Country) rock is homogeneous, glossy, and thick lamellar, dark-blue slate; the planes of its cleavage range nearly N.E.— S.W., and dip 15°—25° S.E.; whilst the joints which intersect it bear 20°—25° W. of N.—E. of S., 20°—25° N. of E.—S. of W., and 40°—45° N. of E.— S. of W. respectively. Two, nearly parallel, lodes, running about N.— S., dipping 80°—86° E., and averaging from two to three feet in width, have been wrought, one to about eighty, the other to more than one hundred and thirty, fathoms in depth. The shallower parts of both consisted of granular quartz, slaty-clay, and earthy brown iron-ore, slightly and irregularly sprinkled with iron-pyrites, copper-pyrites, blende, and galena ; but beneath, the quartz assumed some characters of horn- stone, calcareous matter appeared, and—at intervals—the lodes were rich in galena, which—differing in quality on opposite sides of the N. cross-vein, —yielded from 0 000746 to 0 001201 its weight of silver. Three cross-veins, all bearing about E. — W., dipping S. 60°—70°, and measuring usually from one foot to three feet—in one case, however as much as eighteen feet—in width. All three intersect both the lodes; but whilst the southernmost cross-vein \ heave both the hdes towards the right -hand and the middle „ $ (R.-R.A.), >» northernmost heaves left-hand (L.-R.A.). The cross-veins consist generally of slaty clay, mixed with granular quartz, calcareous-spar, the carbonate of iron, and iron-pyrites ; but, here and there, they contain masses of hornstone-quartz, small quantities of copper-pyrites, and isolated bodies of galena. Between the severed portions of the easternmost lode , at a depth of from ninety-three to one hundred and ten fathoms, however, the northern cross-vein afforded single crystals of—but slightly argentiferous— galena imbedded in large bunches of vitreous silver ; crystalline granules, some¬ times of ruby silver (pyrargyrite), and yet more frequently of vitreous silver, sprinkling crystals of quartz and of calcareous spar, in numerous small (vughs) cavities; and earthy black silver-ore investing as well crystals of galena, as flakes and threads of native silver. This spot yielded 304*7743 tons (Avoir.) of, more or less, argentiferous galena; which—ranging in price from £1:7:6 to (£2 : 14 : 0 per lb.) £6,048 per ton—realized, in 1861—3, £22,501 : 8 : 6. Salmon, Mining and Smelting Magazine , n. pp. 78—83, Fig. 2, 3, 4. Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District, pp. 18—24, Fig. 1. Ante, pp. 120—1, Note. Menheniot , Lanreath, and Saint Pinnock. 711 Rectangular impressions occur on quartz in some, The following columns—compiled by John Taylor, Esq., Purser of Wheal Ludcott, from accounts kept at the mine,.— show the quantities of ore obtained from the northernmost cross-vein ,—proportions of silver and of lead contained in the ore,—the prices at which the several 'parcels were sold,—and the proceeds of each sale. Weight (Ac.) Proportions of Price per (Av.) Amount. Date. of ore. ton. tons. cwt. qrs . lbs. Silver. Lead. £ s. d. £ s. d. 1861 Sept. 27th 2 19 3 0 0-037026 0 202500 290 14 6 868 10 9 99 9 2 3 0 — — 47 6 0 431 17 10 Nov. 13th 9 18 0 0 — — 22 14 3 223 17 6 1862 Jan. 4th 23 3 3 0 — — 2 0 6 46 18 8 13 th 1 0 0 0 0 073401 0 175000 694 0 0 694 0 0 Feb. 22nd 1 4 2 0 0 067449 0-112500 652 10 0 799 6 3 March 1st 13 5 0 0 0*003265 0-081250 25 7 6 336 4 4 22nd 10 0 0 0 0-000612 -- 1 7 6 13 15 0 27th 2 0 0 0 0-048513 0-137500 457 4 0 914 8 0 April 3rd 1 2 0 0 0-025423 0-375000 235 0 0 258 10 0 9th 1 18 2 0 0-033554 0 137500 367 6 6 707 1 10 99 13 0 1 0 0-004635 0-075000 33 15 0 439 3 0 May 10th 3 10 3 8 0 041866 0 016250 378 0 0 1,338 10 6 June 5th 20 0 2 0 0-004548 — 31 15 0 635 15 10 July 1st 3 14 2 10 0 050146 0-137500 464 0 0 1,730 9 4 99 3 12 0 0 0-007959 0-400000 80 15 0 290 14 0 Aug. 18th 1 1 1 23 0-095977 0-237500 878 0 0 941 17 9 99 3 14 1 11 0-039388 0-112500 380 7 0 1,413 18 3 9 * 25 4 1 0 0-004373 — 34 2 6 860 7 6 Oct. 6th 3 18 3 22 0-042274 0-131250 382 0 0 1,507 17 6 99 1 12 1 20 0 018512 0-306250 116 1 6 188 4 0 99 32 19 1 0 — — 9 12 0 316 8 9 Nov. 25th 1 0 3 7 0-048338 0-156250 422 10 6 439 13 9 99 5 7 3 8 0 022158 0-137500 224 10 6 1,210 8 6 99 23 8 0 0 0-001633 _ 10 1 0 235 3 4 1863 Jan. 5th 7 2 2 0 0 036152 0-137500 343 16 6 2,449 15 0 99 6 7 1 18 0 006006 0-125000 63 14 6 405 19 2 99 19 9 3 0 0 001166 -- 10 2 6 197 6 2 April 6th 4 11 2 6 0 025423 0-106250 223 9 0 1,022 17 7 9} 3 7 1 21 0-003265 — 35 0 0 118 0 3 99 21 18 3 0 0 001633 — 9 10 6 208 19 0 9} 0 0 2 27f — a — 6,048 0 0a * 226 2 6 99 0 0 2 18 h — b — 4,592 0 05 152 14 6 99 0 0 1 2- ■^4 — c — 4,986 0 0c 67 6 1 99 0 2 3 20 — d — 1,568 0 0 d 229 12 0 July 13 th 4 14 0 0 0-010262 0-150000 93 15 0 440 12 6 99 18 19 3 0 0 001253 — 7 6 6 139 1 7 Totals .. 304 15 1 26ie £99. 601 8 6e Mean .. £ 73 16 8 a £ 2 : 14 : 0 per lb. (Avoir.). c £ 2:4 : 6 per lb. ( Avoir )• b 2 : 1 : o „ 99 • , d 0 : 14 : 0 „ 9 • e “ 1861.. 12 tons 2 cwt. 2qrs. value £1,300 : 8:7) ('Hunt , Memoirs of the Geol. Survey 1862.. 193 ,, 19 ,, 1 ,, ,, 14,624 : 13 : 9 > j of Great Britain (Mineral Statis- 1863.. 86 „ 14 „ 0 „ „ 5,658 : 6:4)1 tics), for 1861, p.40; 1862, p. 30; --1863, p. 45. 292 „ 15 „ 3 „ „ £21,583 : 8:8” 712 W. J. Henwood, on the Lead-Mines of and casts of hexagonal pyramids on iron-pyrites in other, parts of the lode ; but the substances to which they owe their origin have disappeared. Many parts of both lodes enclose thin (horses ) slices of rock, which take the same directions and dips as the branches on either hand ; * * but, at the same time, are of identical composition, and jointed and cleaved uni¬ formly, with the immediately contiguous (Country) strata. These included masses are, perhaps, as often sharply defined as they are transfused with siliceous and calcareous matter; in both cases they are occa¬ sionally penetrated, from either side, by slender strings of the vein-stones. The metalliferous portions (or leaders ) are, now and then, separated from the containing (Country) rocks on either of, or on both, their sides by bodies of breccia;^ in which a nucleus of quartz occasionally \ * “ At the 80 fathoms level [in Wheal Mary Ami\ the lode is divided into two parts, one part runs towards and enters the elvan on the E. side, while the main part of the lode traverses the W. side of it, and still preserves the regular underlie.”— Giles, Cornwall Geol. Trans., vii. p. 206. f “ Connected with the [Menheniot] lode ,— and forming as it were a transition between it and the adjoining rock,—is a mass of angular pieces of slate, ce¬ mented by quartz, which is often crystalline, and sometimes presents small cavities lined with minute crystals. This brecciated structure,—locally called capel or cab, —seldom extends more than four or five feet from the lode, —never contains much lead-ore,—and is rather more common on the western or lower side of the lode than on the eastern. The lamination of the schistose portions of this—apparently fragmentary—deposit, approximates, though with some ex¬ ceptions, that of the contiguous slate-rocks. Contrary to the prevailing opinion respecting a similar structure in copper districts; it is, throughout the lead- mines of the neighbourhood, considered a favourable indication.” —Henwood, Reports of the Royal Institution of Cornwall, xxxiii. (1851), p. 42. At Herod’s-foot the lode stoped above the 127 fathom level “ is exceptionally rich. % * * In one part [the galena is of a large grain not rich for silver, Menheniot, Lcinreatli, and Saint Pinnock. 713 seems imbedded in slate, but far more frequently—for the most part indeed—angular masses of slate are enveloped in successive—not uncommonly as many as six—accretions of quartz, each distinguished by some peculiarity of arrangement or hue, and all of more or less radiated structure. # These included kernels are of widely different dimensions ; many being micro¬ scopic,—great numbers measuring less than a quarter of an inch,—but few exceeding two inches. In many cases they are highly siliceous; and thin lines of quartz — at times slightly mixed with either iron- pyrites or galena — intersect or interlie the laminae. The planes of their cleavage are approximately—but not always exactly—parallel; of jointed arrangement they afford no trace. Small cavities, studded with but [within a short distance] it suddenly changes to a very fine grained ore highly argentiferous, making in a brecciated lode, very similar altogether to the rich lead ore found in the Goginan district in Cardiganshire. # # # “ At Wheal Mary Ann the lode south from Pollard’s shaft at the 172 [fathom level] consists of 1^ feet wide of capels and 1 foot of fluor-spar with a little carbonate of lime. * * * & North of Pollard’s [at the same level] the lode is 4 feet wide composed of carbonate of lime and fluor-spar worth 6 cwt. of ore per fathom, with 2 feet of capels on the west side.” Salmon, Mining and Smelting Magazine , n. pp 215,—21. * “ When the forces of cohesion and adhesion are nearly balanced, as in saturated solutions, very slight causes may occasion the cohesion to preponderate ; and when once this force has been set in action, its influence spreads rapidly throughout the mass. # # # Thus, the dropping in of a similar crystal, the insertion of a thread, or of a wire, or of a piece of stick, if not sufficient to cause sudden crystallization, will generally determine the spot upon which the crystals are first formed, especially if the foreign body or nucleus be rough and irregular in its outline.”— Miller, Elements of Chemistry , I. p. 119. “ When a supersaturated saline solution # # # suddenly becomes solid on cooling# # # it will be found that crystallization has been promoted by a minute speck or point at some part of the [containing] tube, and from this point, as from a centre, proceed fine crystalline needles radiating in all directions.” Tomlinson, Proceedings of the Royal Society , xvn. p. 247. 714 W. J. Henwood, on the Lead-Mines of minute botryoidal concretions of agatine structure, encrusted with crystals of quartz, and sprinkled with the carbonate of iron and calcareous spar, occur in all parts of these remarkable deposits.* Towards the S., in Wheal Mary Ann , and through¬ out South Wheal Trelawny which adjoins, as well as between the (N.) old mine and the (S.) new at Merod’s-foot, the lodes are, respectively, represented by mere bunches and short, narrow, strings of slightly- metalliferous vein-stone. j~ These mostly follow such joints as maintain the normal directions of the lodes; but they rarely affect parallel portions of proximate joints. Wherever such small isolated masses of metal- * Tables XXVII., XXVIII., XXIX. t “ The nature of the broken or slidy ground met with in connection with the lead lodes of this district is very remarkable, and well worthy of attention—for it seems to hold all through the district, being equally met with at Mary Ann as at Herodsfoot. The whole strata seem broken up by a succession of disturb¬ ances, of a nature between cross-courses and slides. They are generally called slides in the district, although they are not slides in the proper meaning of the word as used in West Cornwall; but neither are they exactly cross-courses. This broken ground generally extends for a considerable width, shattering and indeed obliterating the lodes to a great extent; although now and then detached pieces—sometimes rich—are found in it. In Herodsfoot it shortens in depth, as in my experience, I have found to be almost invariably the case in broken channels of ground of this kind. % % % [Under] the hopeful counsels of Captain Trevillion the broken ground has been passed through, and what is to all intents and purposes a new mine has been opened out south. % % H: [At Wheal Mary Ann] “ the great run of slidy ground which cuts off the lode southward % % % is very similar to the broken ground in Herodsfoot. # % # The first effect on the lode of the approach of this slidy ground is that it is thrown to the right with a bearing W. 45° S. After the slidy ground is inter¬ sected the lode is not again seen, although the 110 fathom level has been driven considerably S., E., and W. Some branches were more than once met with, but they soon disappeared again, and for the present the trial is suspended.” Salmon, Mining and Smelting Magazine, n. pp. 213 — 14,—21—2. Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District, pp. 17, 27. * Menlieniot , Lanreath , and Saint Pinnock. 715 liferous matter occur, they, and the rocks which con¬ tain them, are traversed by numberless small (flucans) veins of slaty clay. In Herod’s-foot the works, at different depths, were extended, from thirty to forty- five fathoms, through a deposit of this kind,* before the lode which had dwindled, towards the S. in the old mine was recovered in the N. of the new. And at Wheal Mary Ann and South Wheal Trelawny a still greater distance has been laid open* but, hitherto, without success. (c) The cross-veins f observed in this neighbour¬ hood have the undermentioned directions, dips, and dimensions:— Names. Directions. Dips. Wheal Trelawny fiucan 32°—37° S. of E.—N. of W. S.W. 50°—60° Wheal Mary Ann ,, 22°—28° S. of E—N. of W. N.E. 40°—50° Herod 7 s-foot ,, 20°—25° E. of N.—W. of S. N.W. 50°—60° Sizes, feet. 0 5—1-5 02 — 1-0 3-0—4-0 * At Herod's-foot .this broken ground dipped towards the N. „ Wheal Mary Ann .. ,, ,, S. Salmon, Mining § Smelting Magazine, n. p. 212, Fig. 1, p. 219, Fig. 2. f “ The [Menheniot] lead-/or7e is intersected by two flucans ; the northern of them in Wheal Trelawny bears about 10° S. of E., and dips S. 50°—60°; the southern of them in Wheal Mary Ann bears about S.E. & N.W., and dips N.E. 40°—50°. The Wheal Trelawny fiucan varies from six to eighteen inches in width, but the fiucan at Wheal Mary Ann seldom attains a breadth of six inches; both consist of clay identical in composition with the rocks in contact; and frequently the flucans exhibit traces of schistose structure, exactly correspond¬ ing with that of the adjoining slate, of which they are in fact merely softer portions. # # * Thus the lode has the direction of the-barren veins in other districts, and the flucans agree in their bearings,—the one with the lodes and the other with the caunter-lodes in other parts of Cornwall.” Henwood, Report of the Royal Institution of Cornwall , xxxiii. pp. 42—3. “ At Wheal Mary Ann the lode in the 172 fathom level is disturbed by a slide which has been seen in the upper levels and dips north.” Salmon, Mining and Smelting Magazine , II. p. 220. “ At Trelawny the lode, except -where disordered by the slide, of which there are two, is productive throughout a linear distance of 500 fathoms. % % % North of Trehane shaft a slide comes in obliquely, and heaves the lode a little 716 W. J. Hen wood, on the Lead-Mines of Thus, whether both series of lodes be rich,—as they are at Lake Superior* and at Bearhaven; f or the veins of one system be productive and those of the other be barren,—as at Chalanches J and throughout Cornwall § generally ;—such of them as range trans¬ versely and obliquely incline at lower angles, than those which are more nearly parallel, to the meridian. Where the cross-veins of this region traverse beds and masses of felspar and hornblende their chief in¬ gredients are felspathic and hornblendic matter; but when intersecting schistose rocks they consist of slate and slaty-clay, the same planes of cleavage being common to them and to the strata which form their (walls) sides. All parts of them are, more or less, spotted and veined with siliceous matter ; whilst the laminated portions are also conformably interlaid by thin folise of quartz. The cross-veins always intersect the lodes they en¬ counter, || but do not invariably heave them either to the same hand % or towards the same angle; thus,— to the right.”— Webb & Geach, History and Progress of Mining in the Caradon and Liskeard District, p. 37. *Ante, p. 408. f Ibid, p. 603. t Ibid, pp. 526—7. $ Henwood, Cornwall Geol. Trans., v. pp. 247,-77 ; Ante, pp. 675,—82,704, — 11 . || “ The Wheal Trelawny flucan heaves the lode different distances (varying from two to twelve feet) at different levels , but always towards the left-hand, and to the side of the greater angle; the Wheal Mary Ann flucan, which in some places merely divides the lode without displacing it, in others heaves it about two feet towards the right-hand, and to the side of the smaller angle.” Henwood, Reports of the Royal Institution of Cornwall , xxxm. p. 43. U Thomas, Survey of the Mining District between Chasewatcr and Camborne, p. 22; Ante, p. 183, Note t I Menheniot , Lanreath , and Saint Pinnock. 7 17 the Wheal Trelawny Jlucan heaves the lode to the left-hand,* * * § and towards the smaller angle* (L. S.A.) „ Wheal Mary Ann ,, „ Herod's-foot „ the same lode the lode „ right- „ ,* „ right--,, ,* smaller angle* (R. S.A.) greater angle * (R.G.A.) Nor are the heaves of the same lode by the same cross-vein uniform at different depths ; ■j' for— the Menheniot lode at its contact with the Wheal Trelawny Jlucan, Wheal Mary Ann Jlucan, about 30 fms. deep is heaved 12 feet, — >> >> r> 50 55 76 88 5) V V y> r> v v )) v v 10 V )) is heaved 3 feet, „ simply intersected. Moreover, the deeper part of the lode at Wheal Trelawny is intersected by at least one cross-vein which has not been recognized near the surface.J At Wheal Mary Ann, water drawn from the mine, deposits in the steam-boilers troublesomely large in¬ crustations of the sulphate of lime.§ From Wheal Trelawny on the N., and Wheal Mary Ann on the S., the ground slopes gently to a broad, shallow valley, which crosses the lode at nearly right- * Henwood, Cornwall Geol. Trans., v. pp. 316—28. f Ibid, pp. 306—14. Ante, p. 685. I “ In West Wheal Virgin, Poldory, and Wheal Squire innumerable small Jlucans extend but a few fathoms in either direction, and occasion, as it were rents in the middle of the lodes , but neither rise to the surface, nor descend tO' very great depths. Their results may be compared to rents in the middle, but which do not reach to the edges, of a piece of cloth. —’’Henwood, Cornwall Geol. Trans., ill. p. 320; v. pp. 89, 381. Ante, pp. 226,—87. § “ At Botallack eels thrive as well in pools (sinks) underground as in the stream pumped out of the mine into the engine-pond at the surface; in both cases, however, the water may possibly be more highly charged with sea, than 718. W. J. Henwood, on the Lead-Mines of angles.* * At Herod's-foot, on the contrary, the lode runs nearly parallel to the valley of the Duloe, though at considerable angles to some of its tributary glens. When the Ordnance Geological Survey was made (in 1839) the mineral riches of Menheniot were as yet unknown. The produce of the several mines and the numbers of work-people employed, as well as the power of the steam and water machinery in use, at each of them respectively in the year 1851, are shown on a sub¬ sequent page. with metallic, salt.”— Stephen Harvey James, Esq., Purser of the Mine, MS. Ante. pp. 354—5, 539, Note * . * “ The surfaces of many of the most productive mines are intersected by depressions. Hi Hi Ht The directions of these sometimes coincide with those of the lodes, as at Godolphin, the Consolidated Mines, East Crennis, &c.; but they rather more frequently form considerable but varying angles, as in Herland, Dolcoath, Wheal Tolgus, Wheal Towan. Wheal Leisure, Wheal Friendship, &c.” Henwood, Cornwall Geol. Trans., v. (1843), p. 233. “ The forms of the Cornish hills and valleys have originated in a great measure from the structure of the rocks.”— Boase, Ibid, iv. p. 432. “ From St. Levan to Ludgvan the courses of thirty valleys on the south coast and of eighteen on the north coast Ht Ht Ht run in the direction of the joints. Ht % Ht We may therefore, with much probability, infer that the valleys have been formed along the line of joints, and that the joints existed before the valleys were excavated: thus, the joints governed the direction of the early water-courses, —became enlarged to ravines,—and then to open valleys.” Whitley, Ibid, vn. p. 350. “ A marked feature in the ore-bearing district of [Breage] is the peculiar system of valley-formations Hi % Ht but nowhere is it more plainly seen than at Wheal Yor. The figure of the valley is that of a main trunk with lateral branches having definite rounded terminations, and each having had a small streamlet fed by a spring issuing near its extremity. Near the summit of these hollows, the outcrop of the mineralized portion of the productive lodes has been found.”— Francis, Reports of the Royal Cornwall Polytechnic Society , xxxvi. (1868), p. 20. Menlieniot , Lanreath , and Saint Pinnock . 719 From 1844 to 1868—9 the undermentioned profits have been made in the district; viz.— at Wheal Trelawny # . £56,914 Wheal Mary Ann f .. . . 65,585 Herod’s-foot J ... 49,848 £172,347 As the mines are wrought in a rich agricultural district, heaps of rubbish from them abut on some of the most fertile and best cultivated land in Cornwall. * Wheal Trelawny, f r * e 26th°, f , N P ov!’, 1868; j P roduced ° res whlch reali2ed • • • • £464,981, and afforded a profit of..... 56,914. James Cock, Esq., Purser and Accountant of the Mine, MSS. t Wheal Mary Ann , f to” ‘!T 30th °! SepI ’ 1868! ( >’ ielded ores ' vhich were Sold for ■ ' £454,788 During which period the working-expenses (salaries, } £353 jq 5 wages, tools, &c.) amounted to \ * Royalties (Dues) Profits . 36,098 65,585 £454,788 W. G. Nettle, Esq,, Purser and Accountant of the Mine, MSS. + Herod's-foot, from the 1st of Nov., 1847, \ to ,, 31st ,, Oct., 1859, \ gave a profit of about from „ 1st of Nov., 1859, { to ,, 23rd ,, April, 1869, S £3,000 46,848 £ 49,848 Thomas Trevillion, Esq., Manager and Purser of the Mine, MSS. At Ludcott 8$ Wrey Consolidated Mines (Ante, p. 710), from 1852 to 1865 the amount of capital expended was. £21,388 ,, „ the lead and silver ores obtained were sold for 101,298 During which period the salaries and wages amounted to ,, tools & machinery ,, ,, Royalties (Duesj ,, „ Profit divided amongst) the shareholders .. ) £122,686 £63,835 37,749 8,022 13,080 £122,686 John Taylor, Esq., Purser of the Mines, MSS. Lead-ore obtained, Population employed, and Machinery in use, at the principal Mines in the Menheniot, Lanreath, and Saint Pinnock Districts, during the year 1851, 720 W. J. Henwood, on * Hunt, Records of the School of Mines, i. p. 452. 1 W. G. Nettle, Esq,, Purser of Wheal Mary Ann , MS. t James Cock, Esq., Purser of Wheal Trelawny , MS. § Thomas Trevillion, Esq., Purser & Manager of Herod'sfoot, MS. d Double-acting engines. s. Single-acting engines. Menheniot , Lanreath , awd Saint Pinnock. 721 The foregoing pages supply descriptions—in greater or less detail—of more than one hundred and thirty mines, together with comparisons of the conditions under which the various metals and ores occur in them; but—inasmuch as the chief purpose of this enquiry is to render the experience gained in one country practically useful in another — theoretical speculations have been cautiously avoided. That important parts of many mines have not been described, and that various questions of interest have not been followed to their solution, is owing to no dis¬ regard of one or other; but that the ruinous condition of ancient works or the want of exploratory operations in the former case, and the necessity for considering economic, rather than abstract, subjects in the latter, have narrowed the field of enquiry. Frequent references have been made to the observa¬ tions of earlier labourers* in the same—and other similar—districts; these, however, have been some¬ times abridged; but in every such case scrupulous care has been taken to preserve the exact purport of the original.'!' Notwithstanding certain subjects treated of are but slightly, if they are at all, connected with geological * Of these important statements a few were unfortunately overlooked during the preparation of parts of the work to which they would have been most appro¬ priately quoted : in most, if not in all, such instances, however, they have been subsequently introduced, where—though less apposite—they will still be found illustrative. f All foreign weights and measures have been reduced to their English equivalents. 5 G 722 W. J. Henwood, on Metalliferous Deposits . research, the relations they bear to the history, pro¬ gress, and economy of Mining, may, perhaps, account for their appearance here. I now offer my grateful acknowledgements to the Noblemen and Gentlemen who have afforded me opportunity for examining the mines I have attempted to describe; and mv warmest thanks to the Mine- Agents, Miners, and other friends, to whose kind assistance and judicious advice I have been, on every occasion, so greatly indebted. My obligations to some have been far greater than to others;—but I fear to particularize any, lest—by unintentional omissions— I may give pain to some who most deserve my gratitude. W. J. HENWOOD, 3, Clarence Place, Penzance, 1858, November 16th. 1869, October 23rd. * * 4 1 R vAaH r Y)A\ttkJ I ^ - L. \>J^ ^uho Jr