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merely because it did not at the first glance appear to meet 
all the requirements of the case. 
Mr. Brakenridge, in answer to Mr. Brooke and Mr. 
Jebson, said, — That by the mode I recommend there could 
be no gas in the lower part of the mine through which the 
communication with the drawing pit is kept up, no coal being 
broken down or got there, an explosion would not extend 
far in that direction — it would be very extraordinary indeed 
if it went beyond the bank in which it happened. The con- 
cussion is, no doubt, caused by the rush of air in consequence 
of the explosion, be it greater or less, but from the higher 
temperature and greater lightness of the air on the side 
towards the up-cast, as well as the existing current of air 
from the unaffected parts of the mine, the draught would 
soon be in that direction, and the trap-doors are all so 
constructed as to open in that direction, and not to resist 
the current. This advantage it is utterly impossible to 
obtain by the system of returning the air down banks, and 
back nearly to the point at which it is sent down into the 
mine. The only objection in which I feel there is any 
practical force is that in which a fear is expressed that 
the sixteen yards of coal betwixt the board-gates and the 
bank posts on the outsides of the board-gates, would, by the 
falling of the roof, be so crushed as to stop all communica- 
tion with the ventilating shaft, and prevent that coal being 
got. Now, I admit the force of this objection ; indeed it 
had occurred to myself after I had drawn the diagram. It 
does not at all, however, interfere with the principle, and 
the diagram is laid down exactly as I have seen the works 
in a mine of considerable extent. It has been suggested 
that I should reduce the sixteen yards to ten, and add three 
yards to each of the bank posts. I should not, however, do 
this, my principle being to get and ventilate the greatest 
possible extent of coal with the least possible extent of 
