The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1873-04-10

| IIE-DRlvlNG BY GUNPowDER.-A recent
No. of the Liverpool Courier gives the
following description of IN experiment at
| driving piles hy gunpowder:
| The pile is placed, DIS in an ordinary ma
chine, between the guides in which the
monkey. or "tup," moves. Working be-
tween the same guides, and resting on the
top of the pile, is ca>t-iron cap
OF ton weight, the upper part Of
which has 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 1.SOo
pounds weight. and works in the same
guides as the cannen. This monkey IS or
| ca>t-iron, with stem OF two feet IN length,
| made of wrought-iron, with steel expan'
sion 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 can.
non-bore is throwna cartridge Of compressed
blasting powder, one to two ounces Welght,
whioa is coated with tinfoi or piumbag0, SO
that it will only explode under high heat,
the greatest success seeming to be atttlnea
BY the sloweSt powder. The monkey being
raised to lis place about ten to fifteen 1eet
|@bove the top of the pile, or, rather, tue can
non resting on it, an operator throws into the
cannon-bore cartridge, and the party at the
base pressing on the break 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 b. pressure
similar to that Of a hydraulic machine,
and with n power enhanced from ten TO
twelve times greater than the impact force
due to the weight and fall of thesNoukey
alone, when no cartridge is used. In addi-
ton to which the monkey itself ut the same
moment is thrown up above the cannon
from ten to thirty feet, according to weight
of cartridge. and is automatically caught by
the break at its highest point, and remains
there. held until another pressure OF the
break releases it for the next blow. Thus
the powder is made TO do q double duty In
forcing the pile down while the monkey Is
forced up to the requisite point for the next
blow. The advantages obtained are: -.
1. Rapidtty Of work and perfect conditlon
In which the pile is left, as, although u Is
forced down with SO great dispatch, yet no
rings are ever used OH the bead OF the pile,
as it il never in the slightest degree spnb
or shattered, thus utilizing the entire flie'
and only in extremely stony grouna Is IL ne,
e,ssary even to shoe it, while IN soft ground
the pile drives well even when cut square
Oft at the end. ft5 ft
9. The cheapness by which such machines
can be made 10 do the duty assigned to them
will be apparent when We state that each
cartridge will not average the cost of over q
halfpenny. t.s.,'t.
In the experiment Of yesterday it Is only
Just to state the first four and half feet OF
ground into which the piles were driven
u aS. composed of, brickbats, stones. cinders,
&c, with about, eighteen inches Of original
soil following It, while the sub.strata above
the red sandstone was seven, feet OF marty
clay, with boulders-an exceedingly resist
ant material TO pene,rute'