The New York herald., 1876-09-20
Few Quieting Words About tho
He'll Cato Explosion.

pleteness in the preparations, and chiefly
because there is n smaller number Of vessels
moving upon the river on the stated day of
rest, and because they can all be warned off
with less interruption and Inconvenience to
business on Sunday than at any other time.
The expected explosion of so immense and
stupendous quantity of dynamite and
other giant combustibles as are lodged in the
galleries beneath the Hallett's Point Reef
naturally creates some anxiety and trepida-
ton among the people Of the Immediate
vicinity, who fear q violent atmospheric con-
cussion which may shatter their dwellings
and he attended with danger to life. Wethink
that such fears are unwarranted, although
it may be n point of prudence for people to
retire to safe distance at the time of the
explosion. Tho great sensation caused last
autumn by the explosion Of large quantity
of nitro-glycerine stored on Bergen Hill may
partially account for the exaggerated appre-
tensions felt by some ill-informed people OF
the neighborhood in relation to He'll Gate.
But the cases IRE entirely dissimilar. The
tremendous force suddenly evolved by such
diately surrounding obstacles. If the en-
comprising obstacles slight and frail
nearly the whole force Of the conclusion is
exerted upon the air, producing violent at
mospheric disturbance. This was the case
on Bergen Hill. where the nitro-glycerine
was stored in slight brick structure, with
walls barely thick enough to exclude the
weather. The liberated gases, having no
other resistance to encounter, delivered
their whole force into the surround
ing air, causing o mighty atmospheric
shock, which was communicated to the
buildings in the vicinity and causing
jar which extended to great distances But
even in that case little real damage was done
beyond breaking large amount of window
glass in the immediate neighborhood. The
circumstances of the He'll Gate explosion
will be widely different. Instead of having
little besides the dir to act against the liber-
ated gases will expend the greater part of
their force in destroying the cohesion and
shattering the rocky structure of the reef.
In accomplishing this mighty task they
will have exhausted the main portion of
their energy. If, instead of n submarine
reef, this solid bed of rock were an immense
ledge exposed to the air, the remnant of
force not expended in breaking it to pieces
might toss some Of the fragments to consid-
erable distances and put the surrounding
atmosphere in violent commotion. But it
must be considered that the explosion
is to take place at high tide, when
the reef will be covered by twelve
or fourteen feet of water. The gases,
after having exhausted the greater part Of
their energy in rending and shattering the
immense bed of rock, will encounter the
resistance of the superintendent weight of
water, which they will try to lift up bodily
in their effort to get free. The resisting
weight of such depth Of water is easily
calculated and is really enormous. 1t is o
well-known fact, stated in every elementary
treatise on natural philosophy, that a col
umn of water thirty-two feet in height ex-
erts q pressure Of fifteen pounds on every
square inch of surface at the bottom of
the column. Water twelve feet deep
exerts three-eighths Of that amount of
pressure, or five and five-eighth
pounds to the square inch. There
are 1896 square inches in q square yard,
and an easy process of arithmetic will show
that twelve feet of water presses with
weight of 1890 pounds, or more
than three and half tons, on each
square yard ut the bottom. The
enfeebled gnses will expend nearly the whole
residue of their force, after doing their main
work, in q sudden effort to lift such mass
of water, and when they escape into the free
air they will not retain energy enough to
have much destructive effect. In their up
ward rush they will cause violent and
extensive commotion of the surrounding
waters, making q spectacle well worth the
observation of the curious but there is no
reason for expecting much effect on the
adjacent shores.
We have been thus particular in stating
the manner in which the giant force of the
dynamite will expend and exhaust itself
from wish to allay groundless fears We
reprobate MS heartless and cruel all practical
Jokes for alarming the too susceptible minds
of ignorant people who merely know the tre-
mendous energy imprisoned in vast quanti-
ties of dynamite but do not understand
the manner in which that energy is
expended and exhausted by acting against
and overcoming mighty distractions.
Moreover, reasonable confidence in Cen
cral Newton should have n reassuring effect
He has been engaged for several years in this
important work, constantly drilling and
blasting. week in and week out, and there is
no instance on record where so much blast
ing has been done with SO small number
of casualties. The slight loss of life during
this long period seems almost miraculous;
but it is really no miracle, but signal proof