146 Chronicles of Science. [ Jan. 
atmospheres, which at 100 strokes per minute, when expanded to 
its natural volume, gives about 300 cubic feet of air, this supply can 
be sent into each working face. This air, in expanding, takes heat 
from all surrounding bodies, thus lowering the temperature of the 
mine; and it, at the same time, increases the current, and dilutes the 
noxious agents which are found, as the preducts of respiration and of 
combustion, or such as are evolved from the coal itself. The advan- 
tages of these machines are most satisfactorily proved, and many coal 
proprictors have made arrangements for their introduction to their 
several works.* How will the invention be received by the mining 
population ? is a question which many ask. Since the machine is to 
relieve the miner from his heaviest labour—to do, indeed, the drudgery 
of the pit—and thus tend to alleviate his condition, reserving his 
strength for less injurious trials, he cannot but feel that the aid 
afforded him is great, and we hope that he will receive it with ali 
thankfulness. 
In our anxiety to describe clearly the coal-cutting machines, so 
much space has been absorbed, that we feel compelled to defer to our 
next Number all notice of two or three machines—which have been 
devised, for working upon our hardest rocks,—used in driving levels 
and proposed for use in sinking shafts in our metalliferous mines. 
If the collier be exposed to injurious influences—and subject to 
violent casualties—the metalliferous miner is subjected to conditions 
so much more distressing, that, although we seldom hear of such dire 
calamities as those which follow from an explosion of fire-damp, it is 
too well known that the number who perish young, from the con- 
sequences of their labour, is fur greater, relatively, than the deaths 
occurring amongst the coal-miners. Every mechanical aid, therefore, 
which proves a benefit in one case, becomes a yet greater blessing in 
the other. We expect before our second Number can appear, that the 
Report of Lord Kinnaird’s Commission, “To inquire into the sanatory 
conditions of the metalliferous miner,” will have been published, and, 
consequently, it will demand our attention in connection with the 
boring machinery—analogous to that employed in driving the tunnel 
through Mont Cenis—which promises to take the wearying task of 
‘beating the borer” from the failing arm of flesh, and transfer it to 
the resistless arm of iron. 
It is interesting to find, that some successful attempts have been 
made to introduce so much of science amongst our miners as promises 
to facilitate their labours, and relieve them from the liability to error, 
which is ever the attendant on ignorance. ; 
The Miners’ Association of Cornwall and Devonshire, and the 
Mining Schools of Bristol, Wigan, and Glasgow, are doing good work. 
At the same time as those local institutions, supported by limited 
subscriptions, are earnestly at work, the Royal School of Mines in 
London, supported by an annual vote from the House of Commons, 
is providing a numerous staff of young men furnished with all the 
resources of modern science, to undertake the direction of the ore- 
* We believe that the new coal cutting-machine has been at work three months 
or more at the Ince Hall Colliery.—Ep. 
