597 
a strong current as to cause much inconvenience to the 
pitmen, and to induce them to counteract it hy putting up 
or removing brettices as they frequently do. 
The lightness and specific characteristics of the gas 
sufficiently indicate the mode and only means by which it 
can be completely expelled from the mine, viz., by a con- 
tinuously ascending current of air or ventilation ; and by 
the mode I recommend, the gas, instead of being, as at 
present, driven upon the men at the bank faces, is at once 
carried away from them as it is liberated from the coal. By 
this mode of ventilating, there is no necessity to travel the 
air so far as in the usual mode and practice, till it is over- 
powered by the gas, even till it becomes in itself explosive. 
Should, from any cause, which (the rules laid down being 
carefully attended to) I am, I confess, unable to foresee, an 
explosion take place, whether partial or general, it would 
be in the goaves, and its force towards the furnace and 
up-cast, and the men would have the ready means of escape 
down the 1 ' board-gates " in the solid coal to the drawing 
pit, instead of, as is generally the case under the present 
system, being cut off by the fire from the drawing pit, till 
even, if they escape death from the explosion, they are 
deprived of life by the " choke" or after-damp. There can 
be no doubt that a large number, probably one-half, of the lives 
sacrificed at Lund-hill was caused by " choke-damp." Again, 
by this mode a less quantity and force of air is required to 
keep the mine pure than by the ordinary mode, by which 
the gas can only be forced down the boards from the bank 
faces by an inconveniently strong current of air ; whereas, 
by this mode, the air is not required to travel far against 
the bank faces, there is little danger of its becoming 
surcharged with gas, and the current is always ascending 
in accordance with the natural impulse of the gas. By 
this mode of working and ventilating, there is little or no 
