(8.) 
(fo to fpeak) Air through the Tube, without which it cannot 
burn, which yet it will do 5 as is obvibus to conceive , (all II- 
luftrations, and Philofophicai EKplications being here fuper- 
fluous,) and foj while the Air is drawn by the fire from the far- 
theft or moft inward part of the Mine or Adit^ frelh Air rauft 
needs come in from without^to fupply the place of the other, 
which by its motion doth carry away with it all the vapors^ 
that breath out of the ground i by which means the whole 
AditmW be alwaies filled with frcfh Air^fo that men will there 
breath as furely as abroad, and not only Candles burn , but 
Fire, when upon occafion there is ufe for it for breaking of 
the Rock. 
Now that there may be no want of fuch frelh Air, the Fire 
muft alwaies be kept burning in the Chimney , or at leaft as 
frequently as is neceffary: For which purpofe there muft be 
two of the Iron Grates or Chimneys, that when any accident 
befab the one, the other may be ready to be in its place, the 
Coals being firft well kindled in it: but when the fire is neer 
fpent.the Chimney or Grate being haled up to the dorejis to 
be fiipplied with frefli fuel 
The Figure of the Fabrick, Chimney, and all the parts 
thereof being hereunto annexed,the reft will bceafily under- 
ftood. 
Figure 1. 
A. The Hole for taking out the Aflies. 
The Sqimre-hole^ into which the Tube or Pipe for convisy- 
ing the Air is to be fixed. 
C. The Border or Ledge ofBric\ or Iron^ upon which the Iron- 
grate or Cradle^ that holds the burning Coles^is to reft, the one 
being exa(9:ly fitted for the other. 
Z). The Hole where the Cradle is fet. 
£. The woodden Tube, through which the Air is conveyed 
towards the Cradle, " 
F, The Dore^ by which the Grate and Cradle is let in^ which is 
M 2 to 
