Year: 1873

A recent number OF the Liverpool
Courier gives the following description
of an experiment at driving piles by
gunpowder:


The pile is placed, as in an ordinary
machine, between the guides in which
the monkey, or ''tup," moves. Work
ing between the same guides, and rest
ing on the top of the pile, is cast-lron
cap of ton weight, the upper part OF
which has q cylindrical hole OF seven
inches diameter, bored to the depth Of
about two feet. This cap, or cannon,
rests on and follows down the pile with
each stroke of the monkey, which is OF
1900 pounds weight, and works in the
same guides as the cannon. This
monkey is of cast-iron, with a stem OF
two feet in length made OF wrought
iron, with q steel expansion ring at its
termination, and this stem enters easily
to the extreme depth Of the bore OF the
cannon below it, when the monkey Is
allowed to descend. Into the cannon
bore is thrown cartridge OF compressed
blasting powder, one to two ounces
weight, which is coated with tinfoll or
plumbago, so that it will only explode
under high heat, the greatest success
seeming to be attainable by the slowest
powder. The monkey being raised to
it's place about ten to fifteen feet above
the top Of the pile, or, rather, the can
non resting on it, an operator throws
into the cannon bore cartride, and the
party at the base pressing on the brake
allows the monkey to fall with Its stem
into the cannon's mouth, when, by the
sudden compression Of the air in it,
enough heat is generated to explode the
cartridge, the effect Of which is, first, to
force down the pile by pressure siml.
lar to that Of hydraulic machine, and
with a power enhanced from ten to
twelve times greater than the impact
force due to the weight and fall OF the
monkey alone when no cartridgeis used.
In addition to which the monkey itself
at the same moment is thrown up above
the cannon from ten to thirty feet, ac-
cording to weight of cartridge, and is
automatically caught by the brake at
its highest point, and remains there
held until another pressure OF the brake
releases it for the next blow. Thus the
powder is made to do double duty in
forcing the pile down while the monkey
is forced up to the requisite point for
the next blow. The advantages obtain
ed are:


First-Rapidity of work and perfect
condition in which the pile is left, as,
although it is forced down with 30 great
despatch, yet no rings are ever used on
the head Of the pile, as it is never in
the slightest degree split or shattered,
thus utilizing the entire pile, and only
in extremely stony ground is it neces.
sary even to shoe it, while In soft
ground the pile drives well even when
cut square off at the end.


iSecond-The cheapness by which
such machines can be made to do the
duty assigned to them will be apparent
when we state that each cartridge will
not average a cost of over halfpenny


In the experiment of yesterday it is
only Just to state the first four and O
half feet of ground into which the piles
were driven was composed OF brick,
bats, stones, cinders, &C., with about
eighteen inches of original soil follow.
ing it, while the substrata above the red
sandstone was seven feet Of marly clay,
with boulders-an exceedingly resistant
material to penetrate.