VOL. I.] PHILOSOPHICAL TRANSACTIONS.. 27 



opportunity of observing, to endeavour the discovery of a matter of that import- 

 ance, which would prove one of the greatest analogies for the earth's motion. 



Adits and Mines ivrought at Liege ivithoiit Air-shafts. By Sir Robert 



Moray. N° 5, p. 79- 



Amongst the expedients that have been devised to remedy the inconvenience 

 from the want of fresh air, 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 of which is as follows : — 



At the mouth or entry of the adit there is a structure raised of brick, like a 

 chimney, about 28 or 30 feet high. At the bottom, two opposite sides are, or 

 may be, 5-i- feet broad ; and the other two, five feet : the wall 1-l brick thick. 

 At the lower part of it is an aperture nine or ten inches square, for taking out 

 the ashes ; which when done, this ash-hole is immediately stopped so close, that 

 no air can possibly get in. About three feet above ground, or more, there is on 

 the side that is next to the adit or pit, a square hole of eight or nine 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, the joints and chinks of which are so stopped 

 with parchment, pasted or glued on them, that the air can have no admittance but 

 at the end: And this pipe is always lengthened as the adit or pit advances, by fit- 

 ting on new pipes, so that-one end is always thrust into the other, and the joints and 

 chinks still carefully cemented and stopped 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 re- 

 quisite, the fire within the chimney always draws the air through the tube; 

 tiiere is thus a constant supply of air, which by its motion carries away with it 

 all noxious vapours ; so that men there breathe as safely as in the open air ; and 

 not only candles but fire burns, when upon occasion there is need of it for 

 breaking the rock. 



That there may be no want of such fresh air the fire must always be kept 

 burning in the chimney : For which purpose there must be two iron grates or 

 chimnies, that when any accident befals the one the other may be ready to sup- 

 ply its place ; the coals being first well kindled in it: but when the fire is near 

 spent, the chimney or grate, being haled up to the door, is to be supplied with 

 fresh fuel. 



The higher the shaft of the chimney is, the fire draws the air the better. And 

 this invention may be used in the pits or shafts that are perpendicular, or any 

 how inclining, when fresh air is wanted at the bottom, or in case of noxious 

 fumes or vapours. 



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