The village of Cocaes is not only the prettiest I have seen in Minas, but is also the most beautifully situated. It is built on the gentle slope and summit of a low hill that stands in the bosom of a semicircle formed by the Serra, which in some places is covered with virgin forest, and in others is bare and rocky. Between the Serra and the village runs the Una, a small stream, which, however, in the dry season contains but little water. Everywhere along its banks, and even to a considerable distance, the ground has been turned over and washed for gold; these operations are still carried on. Far from exhibiting the ruin and decay, which the other villages we shortly before passed through presented, the houses here have all a neat appearance, being mostly white-washed, and surrounded by little gardens containing orange and coffee trees, bananas, &c. The church stands out conspicuously from all the other buildings, and around it are planted a few tall palms, which give to the whole place a truly tropical aspect.
On the morning of the second day after our arrival, we left the Arraial de Cocaes; and I thought it very hard to be travelling in the famous El Dorado, with scarcely a sixpence in my pocket, while judging from my first attempt there were but faint expectations of improving my pecuniary wants. Ascending the Serra de Cocaes by an excellent road, and passing the entrance to the mine, we descended to the other side, and following a nearly westerly route for about the distance of four leagues along the base of the Serra, reached the celebrated Gongo Soco mine, about two o’clock in the afternoon. About half way we passed through the Arraial de San João do Morro Grande, which consists principally of one long narrow street. The country around it is formed of a coarse ferruginous soil, that everywhere has been turned up in search of gold, but as it is now nearly exhausted, very few of the inhabitants are engaged in that species of labour. Like most other villages that owe their origin to the auriferous soil in their neighbourhood, it presents all the symptoms of decadence; houses that were built in times of prosperity are quickly falling into ruin, and the few that have been more recently erected, are of a much inferior construction; near the centre of the Arraial is a fine church, still kept in good repair. On the road several English miners passed us on their way to Rio, from a mine which had been established a few years before on the Serra de Candonga, between Tapanhuacanga and Cidade do Serro, but which was now about to be abandoned.
As I brought a letter with me from Mr. Rigby at Cocaes to Mr. T. Baird, one of the partners of a large general store at Gongo Soco, and as I was most kindly received by him, I found myself more comfortably situated than at Cocaes. The whole of the houses at this place belong to the company, and it is undoubtedly one of the prettiest little villages in the province. The situation in which it is placed 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 Mr. Duval, the chief commissioner, the others are all of one story, 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 of the free Brazilian workmen and slaves, employed by the company. There is a catholic priest in the pay of the company, and formerly there used to be an English clergyman also; in this village the officers and the greater part of the English miners reside. The mining operations are carried on about half a mile further to the westward, and the houses of the slaves are situated near the works.
By Mr. Hammond, the chief acting commissioner, Mr. Duval being then on a visit to Rio, and by the other officers I was kindly welcomed to the establishment; and to one gentleman in particular I shall ever feel grateful for his disinterested kindness, and more so from his being a foreigner,—I mean Mr. Virgil Von Helmreichen, the civil engineer of the establishment. Having entered into conversation with me on the nature of my travels and pursuits, he told me that he was well acquainted with Mr. Natterer, the celebrated zoological traveller in Brazil, who had often mentioned to him the awkward situations in which he had frequently been placed, when in the interior, from the want of opportunity to draw for money; and his knowledge of this fact led him to enquire into the state of my funds, which I candidly explained to him, when he very generously offered to let me have as much money as would convey me to Rio, on no other security than my promise to pay it into the hands of his agent on my arrival there. This obliging offer I however declined to accept, until I could ascertain at Morro Velho whether my letters had arrived there or not.
Having expressed a wish to Mr. Hammond to be allowed to visit the interior of the mine, he at once kindly consented, and requested one of the mining captains to escort me: Mr. Ferriar, a young gentleman whom I had formerly met at Rio, offered to accompany me. Before going down, we were taken to the room where the captains keep their mining clothes, and were there obliged to change our dress for one of the suits used in the mines. This consisted of a large coarse flannel shirt, a pair of drawers of the same material, and a coat and trowsers made of coarse canvass, a stout leathern hat which fitted the head tightly, and a pair of strong shoes, which we put on our bare feet. Being thus accoutred, we were each provided with two candles, one which was for immediate use was stuck into a ball of soft clay which served as a candlestick, and the other hung to the button of the coat for after use. Fitted out in this manner, we entered the mine by what is called the Adit level, whence we descended to the next level, seven fathoms deeper; and so on in succession, till we visited seven out of the nine levels, or workings, of which the mine consists; as the two lowest were full of water we could not visit them. The distance between each of the levels is seven fathoms, so that we reached the depth of 294 feet, while the greatest depth is about 378. The excavations in these levels consist of narrow passages or galleries, not more than four or five feet wide, and five or six in height, driven in various directions through the Jacotinga, or micaceous iron schist. This schist is of so soft a nature, that the passages as they are driven require to be strongly lined with wood to prevent their filling up again; and in many places it is quite astonishing to see how some of the thick pillars of hard Brazilian wood, often a foot and a half in diameter, are crushed and broken by the weight from above. The principal gold vein runs to the westward, but there are many ramifying branches. The vein is very unequal in richness, sometimes, as at the period of my visit, yielding hardly any gold, while at others it is found in what the miners call bunches, which are sometimes so rich that more than one hundred pounds weight of the pure metal has been taken out in one day. The rich ore is washed and pounded up in mortars, while the poorer sort is sent to the stamping mills, and afterwards either separated by washing in the Bateia or amalgamated. Notwithstanding the superior richness of this mine, the machinery appeared much inferior to that at Cocaes.
From an excellent diagram constructed by Mr. Helmreichen, exhibiting a section of the country in which the mine is situated, and which he kindly allowed me to examine, I have been enabled to make the following sketch of its geological structure. 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 to the south of the mine, a thick bed of a highly crystallized stratified limestone 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 westward it appears to be inexhaustible, and in that direction all further mining operations will be carried on.
On the morning of the 29th of August, I left Gongo Soco to visit the Morro Velho mine, which is distant about six leagues, in a N.W. direction. I was accompanied only by a guide, having left all my men and luggage at Gongo, as I expected to be absent only about three days. The country between the two places is very hilly and barren, consisting of elevated grassy hills occasionally studded with a few small trees. In the hollows, however, there are generally patches of trees, forming those woods to which the name of Capoes is given. About two leagues and a half from Gongo, we passed through a small straggling village called Morro Vermelho, which was in a state of great decay; and about two leagues and a half further on a still smaller village, called Rapoza, situated on the banks of the Rio das Velhas; we crossed this river over an old narrow, tottering, wooden bridge without rails. On my arrival at Morro Velho about eight o’clock in the afternoon, I found to my great delight, that all my English letters and parcels, which had been accumulating during more than two years, were here awaiting my arrival, which had been expected several months. Letters of credit had also been kindly sent up by Messrs. Harrison, for such sums of money as might be required by me, so that my mind was now quite at ease on that point. I sat up nearly all the night reading my letters, but the state of mind produced by them was far from happy, for not a few of them brought most unwelcome news, of the death of near and dear relations and friends. The kind reception I met with from Mrs. Herring, the lady of the chief commissioner, and from Mr. Crickitt, the acting commissioner for Mr. Herring, who was then in Rio with his two eldest daughters, will ever be remembered by me with gratitude. Rooms were ready to receive me, and instead of remaining only one day, as I originally intended, I was prevailed on to spend about a month at Morro Velho, during which time my health improved rapidly. The day after my arrival, I sent to Gongo Soco for Mr. Walker, the men, and the luggage.
The mine of Morro Velho is situated about half a mile to the S.E. of the Arraial de Congonhas de Sabará. The village, which is very irregularly built, is placed in a hollow, and contains a population of about 2,000 inhabitants; but until the mines in the neighbourhood began to be worked by the English, the population was much less; here are three churches, one of which has never been finished and is now falling into a state of ruin. The mine is situated on one of the hills surrounding the valley, and had been worked by its proprietors for about a hundred years previous to its being bought by the present company. When St. Hilaire visited this village the gold was considered as exhausted,[20] but it now yields perhaps more gold than any other mine in the empire. The present company first commenced its operations about 1830, under the superintendence of Captain Lyon, the northern voyager. This mine is very different from that at Gongo Soco, inasmuch as the auriferous vein occurs in a greyish coloured clay state; the vein, or lode itself, consisting of a kind of quartzose rock mixed with a considerable proportion of carbonate of lime, strongly impregnated with iron and arsenical and copper pyrites; its general direction is from east to west, and it is about seven fathoms wide a little to the west of the central workings, at which point it divides into two branches that run to the westward, while other two extend to the eastward; the more easterly branches are those that have been worked to the greatest extent. These ramifications gradually diverge, and ultimately take a N.E. direction, running parallel to each other, at a distance of about a hundred feet.
The ore is first removed from its bed by blasting, and is afterwards broken by female slaves into small pieces, about the size of the stones put upon macadamized roads, after which it is conveyed to the stamping machine to be reduced to powder; this machine consists of a number of perpendicular shafts placed in a row, and heavily loaded below with large blocks of iron; these being alternately lifted up to a certain height by a toothed cylinder, turned by a large water-wheel, fall down upon, and crush the stones to powder; a small stream of water constantly made to run through them, carries away the pulverized matter to what is called the strakes, a wooden platform, slightly inclined, and divided into a number of very shallow compartments, of fourteen inches in width, the length being about twenty-six feet; the floor of each of these compartments is covered with pieces of tanned hide about three feet long, and sixteen inches wide, which have the hair on; the particles of gold are deposited among the hair, while the earthy matter, being lighter, is washed away. The greater part of the gold dust is collected on the three upper, or head skins, which are changed every four hours, while the lower skins are changed every six or eight hours, according to the richness of the ore. The sand which is washed from the head skins, is collected together and amalgamated with quicksilver in barrels, while that from the lower skins is conveyed to the washing-house, and concentrated over strakes of similar construction to those of the stamping mill, till it be rich enough to be amalgamated with that from the head skins. The barrels into which this rich sand is put together with the quicksilver, are turned by water, and the process of amalgamation is generally completed in the course of forty-eight hours; when taken out, the amalgam is separated from the gold by sublimation. In the whole process, the loss of mercury amounts to about thirty-five pounds a month, but up to two months before my visit, it was nearly double that quantity. For a long time the gold dust was extracted from the sand by hand-washing in Bateias, after the Brazilian manner; but the process of amalgamation is found to be superior, requiring less labour, and extracting a larger proportion of gold. The zillerthal, or running amalgamation process, similar to that used in the Tyrol, has also been tried here, but was not found to answer owing to the great loss of quicksilver. The roasting process has also been attempted, but although by this means the ore yields a much larger per-centage of gold, the fumes arising from the arsenic were found to be so injurious to the health of the workmen, that it was abandoned. A ton of ore produces from three to four Portuguese oitavas of gold; but the same quantity has often yielded as much as seven oitavas. At the time of my visit, from fifteen to sixteen hundred tons of ore were reduced to powder every month.
After having rested about a week at Morro Velho, I started, with Mr. Monach, the surgeon to the company, to ascend the Serra de Piedade, which is the highest part of the great western chain in the Gold district. After travelling about three leagues in a northerly direction, we arrived at the city of Sabará, which, except the Cidade Diamantina, was the largest I had then seen in the interior; it is situated on the north bank of the Rio das Velhas, at the eastern foot of the great chain already alluded to. From the place where the first view of it is obtained, it has a very fine appearance, its site being somewhat elevated, the houses are generally large, and there are several fine churches; the old and new city together are about a mile in length, but the breadth is inconsiderable; the streets are well paved, and judging from the numerous public fountains, it appears to be well supplied with water. It was only about two years before the period of my visit that Sabará was raised to the dignity of a city; the greater part of the inhabitants are shopkeepers, who trade with those of the Sertão to the westward. Notwithstanding its near approach in size to the Cidade Diamantina, it forms a great contrast with it in the stillness of its streets. The ferruginous gravelly soil around it, and along the banks of the river, has all been turned over in search of gold, but now very few seem to be engaged in that pursuit; the bed of the river is said to be rich in gold dust.