Early Copper-smiths and Igorot Native ScienceFebruary 28, 2022
The locality of these rich quarries was still unknown to the Governor, even if the copper implements brought from there had been in use in Manila over 2 centuries, according to an official statement of his in 1833.
The coppersmiths are not negritos but Ygorrotes.
For a long time before the Spanish came, they practised this art, and the still more difficult one of obtaining copper from flint.
They may possibly have learnt them from the Chinese or Japanese.
The chief engineer, Santos,* and many others with him, think that the Igorots are descended from the Chinese or Japanese from whom they acquired their facial features (several travellers mention the obliquely placed eyes of the Ygorrotes), idols, and some of its customs, but also the art of working in copper.
At all events, the fact that a wild people, living isolated in the mountains, should have made such progress in the science of smelting, is of so great interest that a description of their procedure by Santos (essentially only a repetition of an earlier account by Hernandez, in the “Revista Minera," i. 112) will certainly be acceptable.
The present mining district acquired by the society mentioned, the “Sociedad Minero-metalurgica Cantabro-filipina de Mancayán,” was divided amongst the Ygorrotes into larger or smaller parcels strictly according to the number of the population of the adjacent villages, whose boundaries were jealously watched ; and the possessions of each separate village were again divided between certain families; whence it is that those mountain districts
- “ Informe sobre las Minas de Cobre,” Manila, 1862.
exhibit, at the present day, the appearance of a honeycomb. To obtain the ore, they made cavities, in which they lighted fires in suitable spots, for the purpose of breaking the rock into pieces by means of the elasticity of the heated water contained in the crevices, with the additional assistance of iron implements. The first breaking-up of the ore was done in the stream-work itself, and the dead heaps lay piled up on the ground, so that, in subsequent fires, the flame of the pieces of wood always reached the summit; and by reason of the quality of the rock, and the imperfection of the mode of procedure, very considerable down-falls frequently occurred. The ores were divided into rich and quartziferous ; the former not being again melted, but the latter being subjected to a powerful and persistent roasting, during which, after a part of the sulphur, antimony, and arsenic had been exhaled, a kind of distillation of sulphate of copper and sulphate of iron took place, which appeared as “stone," or in balls on the surface of the quartz, and could be easily detached.*
The furnace or smelting apparatus consisted of a round hollow in clayey ground, 30 centimetres in diameter and 15 deep; with which was connected a conical funnel of fire-proof stone, inclined at an angle of 30°, carrying up two bamboo-canes, which were
- According to the Catalogue, the following ores are found :-Variegated copper ore (cobre gris abigarrado), arsenious copper (e. gris arsenical), vitreous copper (c. vitreo), copper pyrites (pirita de cobre), solid copper (mata cobriza), and black copper (c. negro). The ores of most frequent occurrence have the following compositionA, according to an analyzed specimen in the School of Mines at Madrid ; B, according to the analysis of Santos, the mean of several specimens taken from different places :
B Silicious Acid
47.06 Sulphur. . . . . . . 31.715
44.44 Copper :
• . 7539 . . 1.837
. in traces Loss
. : 0.263
fitted into the lower ends of two notched pine-stems ; in which two slips, covered all over with dry grass or feathers, moved alternately up and down, and produced the current required for the smelting.
When the Ygorrotes obtained black copper or native copper by blasting, they prevented loss (by oxidation) by setting up a crucible of good fire-proof clay in the form of a still; by which means it was easier for them to pour the metal into the forms which it would acquire from the same clay.
The furnace being arranged, they supplied it with from 18 to 20 kilogrammes of rich or roasted ore, which, according to the repeated experiments of Hernandez, contained 20% of copper.
They proceeded quite scientifically, always exposing the ore at the mouth of the funnel, and consequently to the air-drafts, and placing the coals at the sides of the furnace, which consisted of loose stones piled one over another to the height of 50 centimetres.
The fire having been kindled and the blowing apparatus, already described, in operation, thick clouds of white, yellow, and orange-yellow smoke were evolved from the partial volatilization of the sulphur, arsenic, and antimony, for the space of an hour; but as soon as only sulphurous acid was formed, and the heat by this procedure had attained its highest degree, the blowing was discontinued and the product taken out. This consisted of a dross, or, rather, of the collected pieces of ore themselves, which, on account of the flinty contents of the stones composing the funnel, were transformed by the decomposition of the sulphurous metal into a porous mass, and which could not be converted into dross nor form combinations with silicious acid, being deficient in the base as well as in the requisite heat ; and also of a very impure “stone," of from 4 to 5 kg. weight, and containing from 50 to 60 per cent. of copper.
Several of these “stones” were melted down together for the space of about fifteen hours, in a powerful fire; and by this means a great portion of the three volatile substances above named was again evolved ; after which they placed them, now heated red-hot, in an upright position, but so as to be in contact with the draught; the coals, however, being at the sides of the furnace. After blowing for an hour or half-an-hour, they thus obtained, as residuum, a silicate of iron with antimony and traces of arsenic, a “stone” containing from 70-75% of copper, which they took off in very thin strips, at the same time using refrigerating vessels; and at the bottom of the hollow there remained, according as the mass was more or less freed from sulphur, a larger or smaller quantity (always, however, impure) of black copper.
The purified stones obtained by this second process were again made red-hot by placing them between rows of wood, in order that they might not melt into one another before the fire had freed them from impurities.
The black copper obtained from the second operation, and the stones which were re-melted at the same time, were then subjected to a third process in the same furnace (narrowed by quarry stones and provided with a crucible) ; which produced a residuum of silicious iron and black copper, which was poured out into clay moulds, and in this shape came into commerce. This black copper contained from 92 to 94 per cent. of copper, and was tinged by a carbonaceous compound of the same metal known by its yellow colour, and the oxide on the surface arising from the slow cooling, which will occur notwithstanding every precaution; and the surface so exposed to oxidation they beat with green twigs.
When the copper, which had been thus extracted with so much skill and patience by the Ygorrotes, was to be employed in the manufacture of kettles, pipes, and other doinestic articles, or for ornament, it was submitted to another process of purification, which differed from the preceding only in one particular, that the quantity of coals was diminished and the air-draught increased
according as the process of smelting drew near to its termination, which inyolved the removal of the carbonaceous compound by oxidation. Santos found, by repeated experiment, that even from ores of the mean standard of 20 per cent., only from 8 to 10 per cent. of black copper was extracted by the third operation ; so
that between 8 and 12 per cent. still remained in the residuum - or porous quartz of the operation.
It was difficult to procure the necessary means of transport for my baggage on the return journey to Paracáli, the roads being so soaked by the continuous rains that no one would venture his cattle for the purpose. In Mambuláo the influence of the province on its western border is very perceptible, and Tagal is understood almost better than Bicol ; the Tagal element being introduced amongst the population by pretty women, who with their families come here, from Lucban and Mauban, in the pursuit of trade. They buy up gold, and import stuffs and other wares in exchange. The gold acquired is commonly from 15 to 16 carats, and a mark determines its quality. The dealers pay on the average 11 dollars per ounce; but when, as is usually the case, it is offered in smaller quantities than one ounce, only 10 dollars.* They weigh with small Roman scales, and have no great reputation for honesty.
North Camarines is thinly inhabited, the population of the mining districts having removed after the many undertakings which were artificially called into existence by the mining mania had been ruined. The gold-washers are mostly dissolute and involved in debt, and continually expecting rich findings which but very seldom occur, and which, when they do occur, are forthwith dissipated;a fact which will account for champagne and other articles of luxury being found in the shops of the very poor villagers.
- According to the prices current with us, the value would be calculated at about 12 dols. ; the value of the analyzed specimen, to which we have before referred, at 143 dols.
Malagúit and Matángo, during the dry season, are said to be connected by an extremely good road ; but, when we passed, the two places were separated by a quagmire into which the horses sank up to their middle.
In Lábo, a little village on the right bank of the river Lábo (which rises in the mountain of the same name), the conditions
to which we have adverted are repeated—vestiges of the works of former mining companies fast disappearing, and, in the midst, little pits being worked by the Indians. Red lead has not been found here, but gold has been, and especially“ platinum,” which some experiments have proved to be lead-glance. The mountain Lábo appears from its bell-shape and the strata exposed in the river bed to consist of trachytic hornblende. Half a league W.S.W., after wading through mud a foot deep, we reached the mountain Dallas, where lead-glance and gold were formerly obtained by a mining company; and to the present day gold is obtained by a few Indians in the usual mode.
Neither in the latter province, nor in Manila, could I acquire more precise information respecting the histories of the numerous unfortunate mining enterprises. Thus much, however, appears certain, that they were originated only by speculators, and never properly worked with sufficient means. They therefore, of necessity, collapsed so soon as the speculators ceased from their operations.
WIND AND WEATHER
North Camarínes yields no metal with the exception of the little gold obtained by the Indians in so unprofitable a manner. The king of Spain at first received a fifth, and then a tenth, of the produce; but the tax subsequently ceased. In Morga’s time the tenth amounted on an average to 10,000 dollars (“ which was kept quite secret”); the profit, consequently, to above 100,000 dollars. Gemelli Carreri was informed by the governor of Manila that gold to the value of 200,000 dollars was collected annually without the help of either fire or quicksilver, and that Paracáli, in particular, was rich in gold. No data exist from which I could estimate the actual rate of produce; and the answers to several inquiries deserve no mention. The produce is, at all events, very small, as well on account of the incompleteness of the mode of procedure as of the irregularity of labour, for the Indians work only when they are compelled by necessity.
I returned down the stream in a boat to Indáng, a comparatively flourishing place, of smaller population but more considerable trade than Daét; the export consisting principally of aback, and the import, of rice.
An old mariner, who had navigated this coast for many years, informed me that the same winds prevail from Daét as far as Cape Engaño, the north-east point of Luzon. From October to March the north-east wind prevails, the monsoon here beginning with north winds, which are of short duration and soon pass into the north-east; and in January and February the east winds begin and terminate the monsoon. The heaviest rains fall from October to January, and in October typhoons sometimes occur. Beginning from the north or north-east, they pass to the northwest, where they are most violent; and then to the north and east, sometimes as far as to the south-east, and even to the south. In March and April, and sometimes in the beginning of May, shifting winds blow, which bring in the south-west monsoon ; but the dry season, of which April and May are the driest months, is
uninterrupted by rain. Thunder storms occur from June to November ; most frequently in August. During the south-west monsoon the sea is very calm ; but in the middle of the north-east monsoon all navigation ceases on the east coast. In the outskirts of Balér rice is sown in October, and reaped in March and April. Mountain rice is not cultivated.