{ "id": "pilares-y-ademes-de-las-minas-de-nueva-espana", "type": "entity", "name": "Pillars and timbering: the ground-support law of the mines of New Spain", "summary": "The mining ordinances of New Spain left standing pillars of the richest ore and forbade the owner to take them. The 1761 commentary explains why: the pillars hold the roofs, carry the ladders, catch a falling man and let the air move, and justices must inspect the timbering because neglect of it is \"en perjuicio de la vida de los Operarios\". The same pages record the conflict of interest — the pillars were of the best metal, and the workmen knew how to rob them.", "locale": "en", "tags": [ "americas", "new-spain", "mining", "law", "occupational-health", "engineering", "labour", "colonial-institutions", "eighteenth-century", "technology", "legal-history", "silver" ], "relations": [ { "rel": "related", "target": "socavones-y-desague-de-las-minas-de-nueva-espana" }, { "rel": "related", "target": "ventilacion-de-las-minas-de-nueva-espana" }, { "rel": "related", "target": "gamboa-comentarios-ordenanzas-de-minas-1761" }, { "rel": "related", "target": "real-tribunal-general-de-mineria" }, { "rel": "related", "target": "real-seminario-de-mineria" }, { "rel": "related", "target": "spanish-mining-law-in-the-american-west" }, { "rel": "related", "target": "barba-arte-de-los-metales" }, { "rel": "related", "target": "beneficio-de-patio-silver-amalgamation" }, { "rel": "related", "target": "mita" } ], "questions": [ "How were colonial mines kept from collapsing?", "Did Spanish colonial mining law protect the lives of mine workers?", "What was despilaramiento and why was it punished?", "How good was the underground engineering of the mines of New Spain?", "Why were pillars of rich ore left standing in Mexican silver mines?" ], "claims": [ { "id": "c1", "text": "The ordinance regulates the geometry of a new mine before anything is taken out of it. When a new mine is discovered, \"los Pozos que se ovieren de seguir, se hagan diez varas uno de otro, y que cada Pozo tenga de hondo catorce estados; y si se oviere de ahondar mas, se haga una Mineta antes que se ahonde mas, y de alli se forme otro Pozo\"; and because in many places the ground will not allow that order to be kept, in such a case what seems most fitting is to be done \"con parecer del Administrador del Partido, y de los demàs Mineros, que desto entendieren\" — an engineering rule with a standing exception decided by the district officer together with practising miners.", "sources": [ "gamboa-comentarios-minas-1761" ], "confidence": 0.9 }, { "id": "c2", "text": "The duty of inspection is stated with the workmen's lives named first among the interests it protects. The chapter's own summary reads: \"Debe la Justicia inspeccionar los ademes, y refuerzos de las Minas, lo que descuidan en perjuicio de la vida de los Operarios, de el Público, y de la Real Hacienda, à que quedan responsables.\" Three interests, in that order, and a liability attached to the officer who neglects the inspection.", "sources": [ "gamboa-comentarios-minas-1761" ], "confidence": 0.9 }, { "id": "c3", "text": "What a pillar is, and the four things it does, are set out in the commentary. If the vein lies inclined, \"se llama Pilar la fuerza que se dexa entre sus dos respaldos, para que estos no se unan\"; if it runs vertical, the pillars are made so that one rests upon another; and the pillar once formed, the working follows, \"quedando assegurados los cielos de las mismas labores, para que no flaqueen, y se hundan\". Beyond holding the roof they serve \"para ir fixando las escalas, y que estèn firmes para dàr descanso à los Operarios: pues aunque cayga un Peòn, no es al centro de la labor, sino que lo recibe el Pilar. E igualmente son importantes para que el ayre devane, y aya respiracion en las labores.\" Roof support, ladder anchorage, arrest of a falling man, and ventilation, from one structure.", "sources": [ "gamboa-comentarios-minas-1761" ], "confidence": 0.9 }, { "id": "c4", "text": "The dimensioning rule is a judgement rule, not a fixed number, and it names its criterion. The distance from pillar to pillar in veins whether inclined or vertical \"debe proporcionarse segun la macicèz, ò debilidad de las Minas: como tambien el gruesso de dos, quatro, ò cinco varas en quadro, segun lo demande la constitucion de el terreno; pues mayor precaucion debe tomarse en unos, que en otros: de suerte, que se consulte à la seguridad de la Mina, y principalmente de las vidas de los Operarios, formando de diez en diez varas el Pilar, ò de ocho en ocho, à juicio, y discrecion de los Prácticos, y segun la mas, ò menos consistencia de el Monte.\" The safety of the mine, and principally the lives of the workmen, is the stated object of the calculation, and the calculation is referred to experienced men on the spot.", "sources": [ "gamboa-comentarios-minas-1761" ], "confidence": 0.9 }, { "id": "c5", "text": "Why the pillars had to be cased in timber is explained without euphemism, and it puts the conflict on the record. The pillars are formed of the solid rock or vein, \"y muchas veces de el metal mas rico de la propria Veta\". The ordinance's requirement that they be covered and timbered with good wood once the ore assays above a marco and a half per quintal \"no es por otra causa, que por conservarlos perpetuamente, y evitar el que los Operarios los destruyan, para hurtar el metal, como lo saben practicar con la mayor destreza, sin Pico, Cuña, ni Barra, y sin que se entienda por el ruido\". If the expense of timber is too great, at the least a guard is to be posted over them, or they are to be faced with the waste rock and loose stones in the wood's place; and in default of the owner \"debe la Justicia hacerlo à costa de el dueño, segun el juicio de Prácticos\".", "sources": [ "gamboa-comentarios-minas-1761" ], "confidence": 0.9 }, { "id": "c6", "text": "Robbing the pillars was an offence the owner could not commit and the judge could not authorise. \"Formados los Pilares; aunque sean de el mas rico metal, no puede destruirlos el dueño, sin incurrir en grave excesso contra las Ordenanzas; ni la Justicia puede darle licencia para que se los coma, derribandolos de el todo, ò descarnandolos, y debilitandolos.\" The chapter's summary adds that the prohibition holds even where wood or stone is substituted for them; that the ordinary jurisdiction to punish despilaramiento is supported by a royal cédula; that the pillars are not to be eaten \"aunque se emborrasque la Mina\", nor the judges remiss in punishing it; and it closes by praising those judges who fulfil this with particular zeal and meet the fraud of stripping a mine and leaving it to flood. The offence is thus named as one committed by owners against a public interest, not only by workmen against owners.", "sources": [ "gamboa-comentarios-minas-1761" ], "confidence": 0.85 }, { "id": "c7", "text": "The rule admits engineering exceptions, and the same chapter carries the drainage fittings with it. Where a mine has natural vaults, pillars are not needed; the depth of the shafts and the distance from one to another are left to the judgement of the peritos; and the piletas — the sumps cut to collect water and lead it to the shaft — are recorded as important for directing the waters to the tiro. Roof support, shaft spacing and drainage are treated as one problem of keeping the excavation standing and working.", "sources": [ "gamboa-comentarios-minas-1761" ], "confidence": 0.85 }, { "id": "c8", "text": "Forty years later an independent and highly qualified witness rated the result. Humboldt, trained at Freiberg and by then the most travelled mining observer in Europe, writes of New Spain that \"la masonería que se emplea en los tiros y cañones, especialmente el ademe de cal, merecen muchos elogios. Las claves de los arcos se ejecutan con mucho cuidado, y en esta parte las minas de Guanajuato pueden competir con todo lo mas perfecto que se ve en Freiberg y en Schemnitz\" — the two foremost mining academies of Europe — his footnote naming Valenciana, Guanajuato and Real del Monte as the works meant. He also records that timber was growing scarcer year by year on the Mexican plateau, which is the context of the masonry.", "sources": [ "humboldt-ensayo-politico-t3-1822" ], "confidence": 0.85 }, { "id": "c9", "text": "The same witness is severe about the rest, and the criticism belongs here as much as the praise. The shafts and still more the galleries of New Spain \"tienen por lo comun el defecto de dar á su abertura dimensiones demasiado grandes, causando por consiguiente gastos exorbitantes\"; at Valenciana the exploratory cañones driven to test a poor vein stand eight or nine metres high; the \"absurda costumbre de abrir todos los cañones con enormes dimensiones\" is what prevents owners from multiplying the exploratory works \"indispensables para la conservacion de una mina, y para la duracion de los laborios\". At Guanajuato the oblique stepped shafts run ten to twelve metres wide and the perpendicular ones six, eight or ten, dimensions forced by the need to admit the cables of six or eight malacates; and the trial made at Bolaños, separating the cables by a timber frame, \"ha probado suficientemente que se puede disminuir la anchura del tiro sin temor de que las cuerdas se enreden\".", "sources": [ "humboldt-ensayo-politico-t3-1822" ], "confidence": 0.85 }, { "id": "c10", "text": "What the pages do not contain has to be said plainly. Not one of them records a collapse, a death, an injury, an inspection actually carried out, or a prosecution for despilaramiento; the praise of zealous judges is general and names no case, and Gamboa is an advocate writing for the mining interest at court, which is why the registry sets his reliability below his tier. The protection of the workmen's lives is stated in the same chapter that treats those workmen's taking of ore from the pillars as theft to be guarded against, and no page read here gives their wages, their hours, the partido they took in ore, or a sentence in their own words. Humboldt's comparison with Freiberg and Schemnitz is a trained man's judgement, not a measurement, and his figures are estimates in a work of political economy. A rule that pillars must stand is evidence of what the law required, not of what the mines were like.", "sources": [ "gamboa-comentarios-minas-1761", "humboldt-ensayo-politico-t3-1822" ], "confidence": 0.9 } ], "takeaways": [], "faqs": [], "evidence_tier": "primary", "evidence": { "level": "industry_observation", "source_types": [ "paper" ] }, "moat_flag": false, "winning_edge": "On the question of whether colonial Spanish American mining law said anything about keeping workers alive underground, the sources that win today answer with the mita, with Potosí, and with nothing else. This entry answers with the ground-support chapter of the ordinances of New Spain and its 1761 commentary, quoted: the justices bound to inspect the ademes because neglect is \"en perjuicio de la vida de los Operarios, de el Público, y de la Real Hacienda, à que quedan responsables\"; pillar spacing set \"de suerte, que se consulte à la seguridad de la Mina, y principalmente de las vidas de los Operarios\"; and the pillar described as catching a falling man — \"aunque cayga un Peòn, no es al centro de la labor, sino que lo recibe el Pilar\" — as well as holding the roof, carrying the ladders and letting the air move. It refuses to make that a clean story. The pillars were of the richest ore; the timbering was ordered partly to stop the workmen robbing them \"sin Pico, Cuña, ni Barra, y sin que se entienda por el ruido\"; the owner who ate his own pillars and left the mine to flood was the fraud the courts were told to meet. And it closes with the outside verdict in both directions: Humboldt rating the lime timbering of Guanajuato against Freiberg and Schemnitz, and calling the oversized galleries of the same mines an absurd custom that cost their owners the exploratory work their survival depended on.", "confidence": 0.85, "last_verified": "2026-08-19", "canonical_url": "https://hispanic-legacy.com/k/pilares-y-ademes-de-las-minas-de-nueva-espana", "api_url": "https://hispanic-legacy.com/api/k/pilares-y-ademes-de-las-minas-de-nueva-espana.json", "jsonld": { "@context": "https://schema.org", "name": "Pillars and timbering: the ground-support law of the mines of New Spain", "description": "The mining ordinances of New Spain left standing pillars of the richest ore and forbade the owner to take them. The 1761 commentary explains why: the pillars hold the roofs, carry the ladders, catch a falling man and let the air move, and justices must inspect the timbering because neglect of it is \"en perjuicio de la vida de los Operarios\". The same pages record the conflict of interest — the pillars were of the best metal, and the workmen knew how to rob them.", "url": "https://hispanic-legacy.com/k/pilares-y-ademes-de-las-minas-de-nueva-espana", "license": "https://spdx.org/licenses/CC-BY-4.0.html", "dateModified": "2026-08-19", "citation": [ { "@type": "CreativeWork", "name": "Ensayo politico sobre el reino de la Nueva-España, tomo tercero", "url": "https://books.google.com/books?id=D5Fla3_P_h8C&pg=PA242" }, { "@type": "CreativeWork", "name": "Comentarios a las ordenanzas de minas, dedicados al catholico rey, nuestro señor, Don Carlos III", "url": "https://books.google.com/books?id=YmY3XDGx24AC&pg=PP7" } ], "@type": "Article", "headline": "Pillars and timbering: the ground-support law of the mines of New Spain" } }