Page:Philosophical Transactions - Volume 001.djvu/86

 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 Dore 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 fastned 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 fastned.

L. The Pulley of Iron or Brass, through which the Chain passeth.

M. A Hook, on which the end of the Chain is fastned by a Ring, the Hook fixed being placed in the side of the Dore.

N. A Barr of Iron in the Walls, to which the Pulley is fastned.

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 unwholsom Fumes or Vapours.

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.

Rh