e, happily, cases of
subaqueous tunneling where the water can be dealt with by ordinary
pumping power, more or less extensive, and where the material is
capable of being cut by a tunneling machine. This was so in the Mersey
tunnel, and would be in the Channel tunnel. In the Mersey tunnel, and
in the experimental work of the Channel tunnel, Colonel Beaumont and
Major English's tunneling machine has done most admirable work. In the
7 foot 4 inch diameter heading, in the new red sandstone of the Mersey
tunnel, a speed of as much as 10 yards forward in twenty-four hours
has been averaged, while a maximum of 11-2/3 yards has been attained;
while in the 7 foot heading for the Channel tunnel, in the gray chalk,
a maximum speed of as much as 24 yards forward in the twenty-four
hours has been attained on the English side; and with the later
machine put to work at the French end, a maximum speed of as much as
27-1/3 yards forward in the twenty-four hours has been effected. In
ordinary land tunneling since 1862 there has been great progress, by
the substitution of dynamite and preparations of a similar nature
for gunpowder, and by the improvements in the rock-drills worked by
compressed air, which are used in making the holes into which the
explosive is charged. For boring for water, and for many other
purposes, the diamond drill has proved of great service, and most
certainly its advent should be welcomed by the geologist, as it has
enabled specimens of the stratum passed through to be taken in the
natural, unbroken condition, exhibiting not only the material and the
very structure of the rock, but the direction and the angle of the dip
of the beds.

Closely connected with tunneling machines are the machines for
"getting" coal. This "getting," when practiced by manual labor,
involves, as we know, the conversion into fragments and dust of a very
considerable portion of the underside of the seam of coal, the workman
laboring in a confined position, and in peril of the block of coal
breaking away and crushing him beneath it. Coal-getting machines, such
as those of the late Mr. Firth, worked by compressed air, reduce to
a minimum the waste of coal, relieve the workman of a most fatiguing
labor in a constrained position, and save him from the danger to which
he is exposed in the hand operation. It is a matter of deep regret on
many grounds, but especially as showing how little the true principles
of political economy are realized by