mensions which shall have been assigned at the commencement of such contramina, and which it is to be eight quarters of a vara for the height, and five for the width. And he shall enjoy this preference with regard to the ore, so long only as there shall be no other deeper mine, producing more benefit to the mines aforesaid, for this right is peculiar to the deepest contramina only. CONTENTS OF THE COMMENTARY ON THESE ORDINANCES. 1. What an adit, or contramina is. 2. Of the advantages derived from adits. 3. It is, in certain cases, a duty to drive these works. 4. The disposition of the ground should be carefully examined by surveyors. 5. Of the fatal consequences of allowing these works to be conducted by incompet ent persons. 6. Of the famous adit of the Vizcayna vein, in the mining district of el Monte. 7. Of the fearful depth of the mines in Pachuca, described with astonishment by Gemelli Carreri. The water has now overwhelmed these mines, burying immense treasures. 8. Of the poverty of the miners, which disables them from driving adits. 9. For want of works of this nature, the mines become irremediably sunk in water, as is the case in many of the mining districts of New Spain. Of the anxious provisions of the ordinance. 10. It is probable that the water will be the ruin of the mines of New Spain, and the evil is to be apprehended with regard to both the continents of America. 11. It seems desirable that the crown should take a share in the expenses and profits of the adits, in the districts of most celebrity. 12. Of the injurious neglect of the justices, in not compelling the miners to open adits, where circumstances admit of it.' 13. Of registering and marking out the adits. They may be opened in ground belonging to another proprietor. 14. A limited dimension is assigned for adits. in the case of the adit of the Vizcayna vein. The rule was dispensed with, as was just 15. Of the exclusive right of the sovereign and the viceroys, to dispense with the regulations on this point, and several considerations on the subject. 16. The adit must proceed in a direct line to the point in view. 17. The proper number of hands for an adit is four workmen. 18 and 19. In the course of the agreement for driving the adit of the Vizcayna mine, the viceroy determined, that it was unnecessary to set on hands in each separate mining pertenencia. Of the discussions which passed, and the modifications subject to which the permission was given. 20. Of levying the contribution to the expenses of the adit, amongst the mine owners concerned, and how it is to be estimated. The parties are compellable to pay the contribution. 21. Of the manner in which an agreement to forfeit all right to the mine, in default of contributing to the adit, is to be construed. 22. The ores found in the course of driving the adit, are to be divided proportionally among the contributors. 23. The 80th ordinance grants to the parties driving the adit the property of the new veins they may discover, although they be in the ground of another proprietor This ordinance reconciled with the 82d, and an explanation given of the course to be pursued in the case of a communication occurring. * Evidently meaning contramina.-Trans. 24. The party driving the adit enjoys the rights of a discoverer, in respect to any new vein he may discover in driving it. 25. The parties driving the adit are to receive payment from those who derive benefit from the work. 26. Although the party driving the adit, be not a mine owner, the contribution must be paid to him. 27. This contribution is to be paid so long only as any actual benefit is derived; but if another adit be made at a greater depth, the contribution becomes due to the proprietor of the latter. COMMENTARY. 1. These four ordinances (which have none corresponding to them amongst the old ordinances), are of the first importance for keeping up the mining districts. They relate to adits, or contraminas, so called, because they are levels or galleries over against a mine. The pit or shaft of a mine is opened from the surface above, but an adit is opened from the foot or side of the hill, and driven to communicate with the pit. The pit therefore, descends from the surface towards the centre, and the adit ascends to meet the pit or pits of the mine. The arrangement of these works, thus explained, is sufficiently clear and intelligible, but may, if required, be seen in various plates given by Agricola.* 2. These contraminas, or adits, which are vulgarly called canones (levels or drifts), are subterraneous conduits or channels, and have for their principal object (amongst others, to collect together the water from several mines, affording one general means of drainage for all of them, and thus rendering it practicable to work parts of the vein, previously under water. This is the grand object of a contramina or work of general drainage. Pits are expensive works, and often become insufficient or unserviceable, either from variations in the course of the vein, or from the great pressure of the water in the deeper levels. But an adit, or contramina, whilst it is a durable and permanet work, provides an outlet to the waters, in their natural course,affords a ready ingress and egress to the workmen, for the purposes of getting out ore and rubbish at a reduced expense, gives opportunities for exploring the principal vein of the mine, and the other veins connected or forming junctions with, or dividing and intersecting it, and by determining the course of the vein, and enabling the proper directions to be given to the different works, promotes the grand object of discovering and turning to advantage the metallic substances hidden in the bowels of the earth. 3. Upon all these grounds then, contraminas being works of the highest importance, both for giving permanence to the mines themselves, and for facilitating their present working, it is provided by the 79th ordinance (notwithstanding the rule that no one ought to be compelled to work his own property), that such works shall be driven, whenever there are conveniences. * Agricola, de re metall. lib. 5, p. 71. usq. ad 74. for the purpose; the mine owners contributing thereto, according to the benefit they may derive from them; and that if they shall not agree, the justice shall apportion the expense, and compel them to make good the payment. 4. The first thing therefore, is to ascertain the disposition of the ground, and the advantages which may be derived from the mines being drained; in estimating which, not only the situation of the mines, but also the condition and depth of the lower works, subject to the water, must be taken in to the account, that it may be ascertained whether the water will flow out with facility. For if the lower workings be as deep or deeper than the point from which the mouth of the adit is to be commenced, little or no benefit can be expect ed, but on the contrary, much expense and loss will be incurred. In the first place then, the ground must be inspected, and a nice survey must be made by persons of skill and practice in geometry, to prevent any risk of failure in an undertaking of such extent and importance. For, if the depth of the pit internally, be equal to the external declivity, measured to the point at which the adit is proposed to be commenced, the expenditure of time and money will be in vain, and the object will fail of effect. 5. We alluded, when on the subject of surveys, to the misfortunes which follow from entrusting works of this nicety to mechanical and ignorant miners, or to persons who, although of more intelligence, have not the skill in geometry required to enable them to form an opinion of the proper length, breadth and depth to be given to these works. And as it is an effort of extreme hardihood in a mine owner, considering the contingencies which arise, to hazard this property, even in works for obtaining ore, so is it a still bolder step to resign himself to the guidance of an ignorant miner, in sinking a pit or driving an adit, matters which necessarily involve considerable expense, and much dead work, without affording any certainty of discovering ore, to redeem the expense. 6. And here we must notice the distinguished merit of Don Joseph Alexandro Bustamante, and his fellow supplier and successor, Don Pedro Romero Terreros, of the order of Calatrava, in driving an adit for the mines of the Vizcayna vein, in the mining district of el Monte, and jurisdiction of Pachuca, from the spot called Dona Juana, or Melgarego. This work having been commenced on the 10th July, 1749, it was found, in the month of January, 1754, by surveys and inspections performed every four months, that the length driven was 856 varas; a work certainly worthy of commendation, and with more reason than some others of its class. This adit was afterwards, by perseverence, activity and energy, carried to a still greater length, and found to be eminently useful: but not till nine years of fruitless labour * Vide sup. chap. 12, n. 14. + Qualis est illa cuniculi de el Venino, qui ducit ad venam ricam Potosiæ, qui improbo labore per 29 annos constructus, 250 ulnas non excedebat. Laet, Americæ descriptio, lib. 11, cap. 9. had been spent in driving an adit from the place called Asoyatla, and afterwards another year in driving another adit from a place called Omitlan, or Guerrero, the two last being in different directions. What money must have been expended, and what patience exerted in these ten years! Bustamante, wearied of so much ineffectual labour, relinquished the prosecution of the work, and gave up his interest in the privileges granted to him by the superior government of Mexico, in the orders under which he had been authorised to undertake the adit; but the Marquess de Valle-Ameno, a partner in the work, and a proprietor of some adjoining mines, persisted in the enterprise, taking up the work from the extreme point of the adit driven from the place called Dona Juana, towards which the watercourses of the mining district of el Monte flowed, and he finally accomplished his object, although frustrated at the other two points, doubtless from not having taken a correct view of the disposition of the ground, of the distance between the mouth of the adit and the bottom workings, and of the depth of the latter below the former. 7. Gemelli Carreri, in travelling through that country in the year 1697, found the bottom workings of the mines of Pachuca to be of very great depth; the mine of Santa Cruz was more than 700 feet deep; that of Navarro, more than 600; and that of San Mateo, 400. Into the latter of these, with a miner's spirit, he descended, and he declares that it was the most foolish action he ever committed for the mere gratification of curiosity. The mine of Trinidad, consisting of the several mines of Campechana, Joya and Peñol, from which he assures us that forty millions of marcs of silver were raised in ten years, by means of as many as one thousand workmen, was so flooded with water, at the depth of 800 feet, that it required sixteen whims to drain it, and the expense of the timber alone, for preventing the falling in of the ground, was estimated at more than twenty thousand dollars. In the early part of the present century, Don Isidro Rodriguez, of Madrid, of the order of Calatrava, sunk much money in these mines; but the irresistible force of the water overwhelmed the property he laid out in them, and the treasures of the mines themselves still remained buried in its depth. After all this, it is impossible to bestow too much commendation on the laudable energy displayed by Don Joseph de Bustamante, Don Pedro Romero Terreros, the Marquess de Valle-Ameno, Don Juan Varandiaram and Don Thomas Tello, and their partners, in undertaking and pursuing, during more than twenty years, from the year 1739, the great work of the adit, notwithstanding the depth of these mines, and the immense body of water contained in them. And the failure of the two first adits, combined with the success of the last, shews what mature deliberation should be bestowed, in planning works of such extent and expense as these; the failure of which is attended * Gemelli Carreri, in his voyage round the world, 23d April, 1697, Histoire general des voyages, tom. 44, in 12. pag. 11. with the most serious loss to the mine owner, who may, on the other hand, by the successful accomplishment of the work, be rendered both rich and powerful. The only way of effecting the latter object, is by having a practical survey of the ground made, under the direction of persons skilled in geometry. 8. In the second place, after considering the disposition of the ground, the attention must be turned to the arrangements required to be made amongst the mine owners, preparatory to driving the adit. This is the greatest difficulty experienced in carrying the 79th ordinance into effect, for although it directs that adits shall be driven wherever there are conveniences for the purpose, or that the owners shall be compelled by the justice to drive them; yet the fact is, that the labour of these undertakings is so great, and the miners so necessitous and destitute of resources, that unless they happen to be men of very ample means, they are but rarely in a situation to undertake an adit of great length, or to expend many thousands of dollars in advance, upon the bare hope of reimbursement upon the draining being accomplished. On the cther hand, if the business be made a partnership concern, the love of money becomes a great bar to its success, and the profit not being of a nature to admit of easy division, it so happens that very few instances occur, of agreements between different parties for undertaking these adits in concert. The miners, provided they have but some ore to work at for the time present, pay but little regard to prospects of a greater profit at a future period, and are alarmed at the idea of expense. They are satisfied with a small profit, and with the ordinary mode of drawing off the water by means of the pit, and they cannot find courage to form a combina. tion for the purpose of driving an adit; not calling to mind, that after a little time, when the works are carried somewhat deeper, their pits will become of little service, whilst an adit or contramina would provide for the permanent and continued working of the mine. And as the veins in mineral regions are found by experience* to incline towards each other, forming junctions at intervals, the consequence is, that having for a time, bread to cut, (as the saying is,) and other mines and veins to work, they are induced, in the hope of benefiting more by pursuing these, to neglect the old and tried mines, which would require an expenditure of money in works of drainage. 9. All these causes combined, render it difficult to put the directions of the ordinance in force, and will in time be the occasion of the ruin and abandonment of the principal mining districts, and indeed may now be observed to operate sensibly in some of them, more particularly in the rich veins of the mining district of Guanaxuato, which has been the Potosi of New Spain, and in those of Pachuca and Zacatecas, which have yielded riches beyond calculation. The productiveness of these veins is matter of notoriety, and has been long well established, and yet a vast number of their * Vide infr. n. 12. |