The New York herald., 1876-09-20

coDeiooraolo. But another point
must DO remembered In this connection. and that 10
the rapidlty Of combustion which 10 posuiarity Of
the explosives used. Water rcssts sudden applics-
tion OF pressure but yields easily to slow This
is very simply illustrated by dropping stono into
pond from great hoght and repeating the operation
close 10 tho II stone 10 thrown or the top
OF High Bridge into the Harlem River it strikes
the with great force, causing break in the
face OF tho river which could only through tho
the stone The slone then sinks the bottom with
comparatively slow descent Now, take another sone
and hold only foot above the water
Drop and will enter the water without any
considerable disturbance and will reach the bottom In
the time did the stone dropped from the great
height II shows therefore, that when a powerful
blow is suddenly administered q water surface the
will be in proportion the energy Of tho
shock, and in this way ii Is possible to show that water
greater obstacle 10 the expansion Of tho gases
from the exploding cartridges than the rock itself that
variable. while that Of The former Is augmented ~
explained above.
With tho cavernous chambers then fllcd with water Il
will DO impossible for the charges to fail in destroying
the rock columns completely, provided the former
are properly located aud of the necessary strength.
Regarding the flooding OF the workings q measure
OF against the projection OF pieces Of rock
II can be reauily seen that II will prove enectuaL
II has been stated by some engineers that be-
masses OF rock we're thrown upward from
great depths OF water by the force Of explosions
that there necessarily danger TO be apprchended
Haletts Point, but The that
this unique work diier wholly from those attendant
on ordinary submarine blasting II has been shown
that the roof rock acts guard against the dying
upward OF pieces from the columns; It has also been
fore. Of that pressure. |. may DO also stated that a
body moving through wafer, either slowly rapidly
tends TO follow tho line OF least resistance,
IRON tho centre OF explosion should nrst
overcome the resistance OF the water, which would
tend decrease its motion; second. it would be
stopped by the descending weight OF the roof rock
and, third, il nehcr Of these influences acted
decidedly It's its should OF
sity be upward in u perpendicular liue, and its fall
az Su a n
direction at less than night angle with its surface
therefore all fear Of flying Jumps OF rock reaching New
York, Astoria Wards Island might bo dismissed
When all the other preparations arc completed the
operation OF filling tho workings Will be accomplished
by means Of siphon which Is arranged TO pass
through the Golfer dam and admit the water with an
easily regulated flow. We present q diagram Of tho
syphon and It's modo OF operation with the present
article When ready to be used and tho tide ut the full
syphon on which the water will At once flow
In and expe the AIR from the entire iength OF the
tube As the tide falls below the level Of
10 depend gravitation. aud Will assume tho charac
ter peculiar TO siphenic action The water will DO
drawn into the tube by the difference OF Of
the atmosphere the surface the short end from
that on tho watcr on tho long end This can be
pressed by the difference between tho weights OF the
long the columns OF water tho operation OF
tho syphon being dependent on disturbance Of tho
equilibrium OF pressure. When the excavation 10 filod
the level the Golfer dam will be partially
moved, as TO admit ot Tree flow OF water and
out, ACCORDING as the tide rises and falla
BOMB PRoOP sHELrHR YOR BATrERIRa
AS an extraordinary precaution against accidents
General Newton has caused TO DO built stout bomb
proof building for sheering the batteries during tho
explosion Tho structure. OF which sketch Is givcn
herewith, 10 solid framework OF heavy timbers
manner and shected ovor with pine boards armiy
spiked TO tho framing Over all this 10 built cover
of dry masonry many ieos thick and strong enough
the assaults OF artillery Within the building
placed the two largo batteries and other apparatus
that are required for the explosion Although this
precautiOn adopted It 10 certain that injury
have reached tho batteries their connections
EyFEcr EXPLOSION.
Although much alarm exists respecting the effect Of
the explosion of much n.roglycerine and dynamite
within contracted space, u wholly groundoss when
erc,ng ~ ca"se U The rosr Columns Which vii, rsav
rcciove the largest share OF the explosives, only
transmit downward shock TO their bases, because
they wholly isolxted from each other by tho
rounding water, and the roof rock through
which shock might be transmitted to the permanent
portion OF tho rccf will be scporated from Il 1t tho
same moment that the columns rent. A heavy
blow that Will DO felt moro at distance from than
~ will not bc Of Character to cause serious alarm
Tho theory OF General Newton regarding the effect Of
the "biow up' perfectly correct Notwithstanding
tho eorts OF the aarmiss that seek To subvert 1t.
The general precautions taken by the officials the
works and tho police will prevent any accident
curing 10 over adventurous persons who may desire
to inspect the scene prematureiy. Such being tho
case the public will await the day fixed for tho
groat ovent with tho utmost confidence
THE ExCrTRMENT OVER THE COMING TxPLo-
s1ox-scAnE AMONG THE PEOPLE OF AsTo-
n1A-A MAY MORNING IN sEPrEMBER-LooK
OUT FOR THIEvEs-rHE WORK APPROACHING
COMPLETION
mo dynamite I" stll the cry at the government
works at He'll Cato yesterday and consequently tho
workmon 'busy doing nothing" as tho foreman
expressed it. In other words they moving scaf-
folding In the tunnels, carrying OF implements
longer required the mine and doing whatever could
1,o to- mt nj mi al AM in
order ready handle tho iously looked material
when II should arrive Carpenters employed all
day building and getting into place series Of
made Of one inch pine plank, each about twolvo feot
long and foot square in tho clear These will be
Joined together ondwse TO form a continuous trough
or case which will from tho bottom of tho SHAFT up
to the surface OF tho ground and thence
Dombproof structure containing the battery. Ra-
dating from the end Of this box, which rests upon
the floor OF the shaft will be smaller boxes OF
similar character ono leading the mouth OF each
heading Through each OF those smaller the
poding wires from its own heading will DO thrust IN
order To keep them from injury falling bodies
othor causes All tho from the 1S9 groups
will thus converge the largor box ppo and pass
through 1t to tho battery. Tho sphon already do
scribed, also completed yesterday.
DYNAMITE COMING.
Late In the afternoon message received from
tho contractors stating that tho dynamite then
being shipped and would be delivered early hour
this morning Should It arrive without ACCIDENT tho
work OF charging tho holes, which Is yet
plcted, will be proceeded with and at tho same
time the nling OF the primers explodsnt cartridges
will 90 in tho little temporary sheds erected for
that purpose four different points upon the grounds
should nothing unexpected happen, tho charg-
ing, putting in the prinaors and flooding tho
excavation will probably all be completed by
Saturday night In that case the explosion
will occur on Sunday nexs, General Newton will not
permit the mino to remain moment longer than is
necessary after the arrang shall havo boen
pleed The General has boon much annoyed by lot
from persons seeking to verify tho correctness Of
statements made by newspapers the effect that tho
'big BLAST would occur certain days He has
been able TO than con ectupe the time