(8i) 
to be fet 8. or lO.foot higher than the Hole D.and the Shutter 
made of Iron, or Wood that will not flirink ^ that it may Ihut 
very clofe ; this Dore being made large enough to receive the 
CraMe with eafe. 
G. The Grate or Cradle^ which is narrower below than a- 
bove,that the Aflies may the more cafily fall^and the Air excite 
the Fire ; the bottom being barred as the fides. 
H. The Border or Ledge of the Cradle ^ that refts upon the 
Ledge C. 
L Four Chains of Irm faftncd to the four corners of the 
Cradle, for taking of it up,and letting of it down. 
The Chain of Iron, to which the other are faftncd. 
L. The PuSey of Iron or Brafs^ through which the Chain paf- 
fetb. 
M. A Hqo\ 3 on which the end of the Chain is faftned by a 
J{ing, the Hoo\ fixed being placed in the fide of the Dore. 
2V. A Barr of Iron in the Walls, to which the PuBey is faftned. 
The higher the Shaft of the Chimney is 5 the Fire draws 
the Air the better. And this Invention may be made ufe of 
in the Pits or Shafts ^ that are Perpendicular , or any wife incli- 
mng towards it, when there is want of frefh Air at the bottom 
thereof, or any molcftation by unwholfom Fumes or Vapours. 
A w^y to breaJ^eafily and fpQcdily the hardefl 
Rocks^ communicated by the fame Perfon^ 
as he received it from Monfieur Du Son^ 
the Inventor. 
Though the Invention of breaking with eafe, and difpatcb, 
hard Rocks, may be ufeful on feveral occafions, the benefit is 
incomparably great , that may thereby accrue to thofe, who 
have ASts or PafTages to cut through hard Jiockj^ for making 
paflTage for Water to run out by, in Mines of Lead, Tin, or any 
other whatfbeverithefe Adits appearing to be the fureft, chea- 
peft, and moft advantagious way imaginablcj for draining of 
the fame. That 
