An Account, How Adits & Mines are Wrought at Liege without Air-Shafts, Communicated by Sir Robert Moray

PHILOSOPHICAL TRANSACTIONS. Monday, July 3, 1665. The Contents. An Account, how Adits and Mines are wrought at Liege without Air-shafts, communicated by Sir Robert Moray. A way to break easily and speedily the hardest Rocks; imparted by the same Perlon, as he received it from Monsieur Du Son the Inventor. Observables upon a Monstrous Head. Observables in the Body of the Earl of Belcarres, sent out of Scotland. A Relation of the designed Progress to be made in the Breeding of Silk-worms, and the Making of Silk, in France. Enquiries touching Agriculture, for Arable and Meadows. An Account, how Adits & Mines are wrought at Liege without Air-shafts, communicated by Sir Robert Moray. It is well known to those conversant in Mines, that there is nothing of greater inconvenience in the working or driving, as they call it, of Mines or Adits underground, for carrying away of Water, or such Minerals as the Mine affords, than the Damps, want, and impurity of Air, that occur cur, when such Adits are wrought or driven inward upon a Level, or near it, 20, 30, or 40 fathom, more or less: Aftewel because of the expence of money, as of time also, in the Ordinary way of preventing or remedying those inconveniences; which is, by letting down shafts from the day (as Miners speak) to meet with the Adit; by which means the Air hath liberty to play through the whole work, and so takes away bad vapours and furnishes good Air for Respiration. The Expence of which shafts, in regard of their vast depth, hardness of the Rock, drawing of water &c. doth sometimes equal, yea exceed the ordinary charge of the whole Adit. Amongst the Expedients that have been devised to remedy this, there is one practised in the Coal-mines, near the Town of Liege (or Luyck) that seems preferable to all others for Efficacy, Ease, and Cheapness: the description whereof followeth. At the mouth or entry of the Adit there is a structure raised of Brick, like a Chimney, some 28. or 30. foot high in all: at the bottom, two opposite sides are (or may be) some $5\frac{1}{2}$ foot broad; and the other two, 5. foot: the wall 1'. Brick thick. At the lower part of it, is a hole, some 9. or 10. inches square, for taking out of the Ashes, which when it is done, this Ash-hole is immediately stopt so close, as Air cannot possibly get in at any part of it. Then, some 3. foot above ground or more, there is on that side, that is next to the Adit or Pit, a square hole of 8. or 9. inches every way, by which the Air enters to make the Fire burn: Into this hole there is fixed a square Tube or Pipe of Wood, whereof the Joints and Chinks are so stopt with Parchment pasted or glewed upon them, that the Air can nowhere get in to the Pipe but at the end: And this Pipe is still lengthened, as the Adit or Pit advanceth, by fitting the new Pipes so, as one end is alwaies thrust into the other, and the Joints and Chinks still carefully cemented and stopt as before. So the Pipe or Tube being still carried on, as near as is necessary, to the wall or place, where fresh Air is requisite; the Fire within the Chimney doth still attract (81) (so to speak) Air through the Tube, without which it cannot burn, which yet it will do, as is obvious to conceive, (all Illustrations, and Philosophical Explications being here superfluous,) and so, while the Air is drawn by the fire from the farthest or most inward part of the Mine or Adit, fresh Air must needs come in from without, to supply the place of the other, which by its motion doth carry away with it all the vapors, that breath out of the ground; by which means the whole Adit will be alwaies filled with fresh Air, so that men will there breath as surely as abroad, and not only Candles burn, but Fire, when upon occasion there is use for it for breaking of the Rock. Now that there may be no want of such fresh Air, the Fire must alwaies be kept burning in the Chimney, or at least as frequently as is necessary: For which purpose there must be two of the Iron Grates or Chimneys, that when any accident befals the one, the other may be ready to be in its place, the Coals being first well kindled in it: but when the fire is neer spent, the Chimney or Grate being haled up to the dore, is to be supplied with fresh fuel. The Figure of the Fabrick, Chimney, and all the parts thereof being hereunto annexed, the rest will be easily understood. Figure 1. A. The Hole for taking out the Ashes. B. The Square hole, into which the Tube or Pipe for conveying the Air is to be fixed. C. The Border or Ledge of Brick or Iron, upon which the Iron-grate or Cradle, that holds the burning Coles, is to rest, the one being exactly fitted for the other. D. The Hole where the Cradle is set. E. The wooden Tube, through which the Air is conveyed towards the Cradle. F. The Dore, by which the Grate and Cradle is let in, which is to be set 8. or 10. foot higher than the Hole D. and the Shutter made of Iron, or Wood that will not shrink, that it may shut very close; this Door being made large enough to receive the Cradle with ease. G. The Grate or Cradle, which is narrower below than above, that the Ashes may the more easily fall, and the Air excite the Fire; the bottom being barred as the sides. H. The Border or Ledge of the Cradle, that rests upon the Ledge C. I. Four Chains of Iron fastened to the four corners of the Cradle, for taking of it up, and letting of it down. K. The Chain of Iron, to which the other are fastened. L. The Pulley of Iron or Brass, through which the Chain passeth. M. A Hook, on which the end of the Chain is fastened by a Ring, the Hook fixed being placed in the side of the Door. N. A Bar of Iron in the Walls, to which the Pulley is fastened. The higher the Shaft of the Chimney is, the Fire draws the Air the better. And this Invention may be made use of in the Pits or Shafts, that are Perpendicular, or any wise inclining towards it, when there is want of fresh Air at the bottom thereof, or any molestation by unwholesom Fumes or Vapours. A way to break easily and speedily the hardest Rocks, communicated by the same Person, as he received it from Monsieur Du Son, the Inventor. Though the Invention of breaking with ease, and dispatch, hard Rocks, may be useful on several occasions, the benefit is incomparably great, that may thereby accrue to those, who have Adits or Passages to cut through hard Rocks, for making passage for Water to run out by, in Mines of Lead, Tin, or any other whatsoever; these Adits appearing to be the surest, cheapest, and most advantageous way imaginable, for draining of the same.