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attendant on that employment! what is the transition-state by 
which we are now distinguished? Why 4 4 Economy," after 
numerous explosions, and a catalogue of miseries on which we 
will not dwell, although it is not human quite to forget them, — 
and after being "drawn up before his betters" in various wavs 
and places, was made to surrender, and we have at length a 
second shaft conceded, and, happy to relate, the two con- 
structed with very respectably increased diameters and areas; 
so that with the aid of a good fire (or to use a polite expres- 
sion again) the " cupola," we do manage, when all the doors 
are properly shut, and the other etceteras in correct order, 
to get air, though in various degrees of freshness and salu- 
brity, to all the working places of the mine. 
In taking leave of this inquiry, we must again hint, whether, 
in attaining the position we now occupy, as regards the 
practical development and working of collieries in this 
country, Safety and Economy have each had their due share 
of attention ? 
In the review we have taken of its history, we see nothing 
in its pedigree or its perfections to entitle the present system 
to immunity from interference ; and, therefore, I have ven- 
tured, although with a crudeness for which I must apologise, 
to suggest a plan which, if it can be acted upon, should 
render obsolete the very term return-air-courses, by substi- 
tuting a method by which the ventilation should be always 
direct ; and the currents of air having swept through the 
mine, should be discharged by shafts, always in advance, and 
on the rise or more elevated side of the working places in 
which the labour of men or of animals is being employed. 
If this can be accomplished, we not only provide escape 
for the explosive gases in the manner which their natural 
characteristics seem so forcibly to indicate, but we obviate at 
once the most fruitful source of practical danger, by with- 
drawing them from the passages and cavities of the mine, 
