The New York herald., 1876-09-23
VnR HINGE on He'll GATE.
DANGERS from the Explosion Decreased by the
Character Of the Surroundings.
DIRECTIONS OF THE SHOCK.
Description of the Great Exploding
Electric Batteries.
THE ELECTRIC SPARK.
How the Lightning Becomes the Plant
Seritor Of Man.
THE MINE RE A D Y !.
General Abbott's Experiments on
the Velocity Of Vibration.
THE LIBERATED GASES.
How the Lightning Becomes the Plant
Servitor of Man.
THE MINE r e A D Y
General Abbott's Experiments on
the Velocity Of Vibration.
THE LIBERATED GASES.

u forms part, as well a. Win others which oiuer
from 1t in character The danger of local disaster
has been shown TO be very remote on &C
scunt OF the precautions taken at the works
to guard against It. Beyond the possible up
heaval OF some Of the rocky shell which Immediately
underles the Golfer dam, extraordinary scattering
Of the rock aks place. and indeed 1t is more than
probable that this partially exposed portion Will
quietly subsdo into the depths OF the excavation with
the rest OF the superstructure whom the supporting
columns arc blown from under 1t. Distant
buildings. such as those on Blackwsrs and
Wards Islands are in the direct line OF
the reef formation, but there is scarcely
any possibility that they will be seriously affected by
the blast. This assertion Is confidently made the
following basis Of facts Tho Immediately sur
rounding the reef many feet deeper than the bottom
OF the excavation. Between Hallcts Point and Wards
Island the channel which intersects the formation
forty feet depth; In the direction Of the entrance
Of the Harlem River it varies between forty-nve
and hfty-ave feet deep Northwestward toward Ninety
second street the depth between ffy and aityGve
feet, westward toward Horne's Hook, at the foot Of
Eightynnth street, another thckly built up part
Of New York, deepens to nety feet and southwest
ward In the direction Of Blackwes Island the water
Ia seventy feet in depth. Therefore vast trench sur
rounds the reef the water side, which ntercepts as
were any transmitted shock OF tho
reef before any distance from the centre
Of explosion.
The only real connection between the blast and tho
main land is limited TO small Of Astoria which
les over the same rock system that OF Hallctps
Reel But immediately surrounding the point and
Intervening between It and the bullion part Of
Astoria il q deep marshy tract, which presents
kind Of saturated cushion to the force Of tho
explosion, which will the effect Of deadening
considerably aud preventing any of the ground.
II will thus be that although tho charge the
mno is very heavy, nature has surrounded It with a
number oi safeguards, which thoroughly reliable
IN their nterceptng powers The water will undoubt-
edly transmit the shock to considerable
distance, but not directly Each particle or
water will bc affected successfully by
wavc motion, decreasing rapidly in iorce which
dsturbs the water without moving It lateray. Tho
Inverted arch which the alcstion Of tho forms
under the river will transmit Of the shock but as
Indirectly tho water, for obvious The only
nues therefore, that will icel the OF explosion
With anything like jar will be those which radiae
eastward from the reef Another important
point to be remembered in connection with the
lreat blast Is that tho shock only be delivered
licaiIy because laterally the columns and charges
entirely isolated Is possible, therefore, that
observer standing the Palisades the New Jersey
side of the Hudson will feel the shock If any
mlttcd worth noticing, more perccptoly than
observer In the city OF New York. The action
II the explosion on the atmosphere will be
I'LL It In the Immediate vicinity OF the
blast with largo proportion OF highly
hasic gases, which will teud TO expand It,
treating momentary vacuum the blasted rock
INTO which heavy draught of air will set frcm ali
ndes AT once This may cause the demolition of somo
sanes Of glass in tho houses near the works but will
vibration.
BATTERIES.
Among the chef objects soicitudo to the engineers
81 the work the condition and efficiency the exploding
batteries take foremost rank. Any mshap occurring
70 these would involve vexatious delay and failure,
neither Of which would be welcome to New YorKcrs
ust at present AS explained 10 previous article on
he He'll Gate Improvement, eacn group of holes has It's
the latter Is concentrated simultaneously produc-
Ing a series Of almost synchronous explosions.
But, for convenience sake and to guard
aga nst the possibility OF any OF the cells
Of the batteries being neglected at the last moment
they all arranged IN two frames aud protected from
danger by The bomb proof shelter described below.
Tho accompanying cut shows OF these frames
pletey fitted with the troughs and the elements ior
uscd mixture bi-chromate Of potash diluted
,upharic acid, into which arc plunged plates
u zinc and carbon. the former being
1t once acted by the acid. In the sketch these
blcn.cnts are shown h,cu out OF their tronghs by
framework, as 10 pend tho development OF elec
nicity until II requrc, use. When the proper
arrives this framework on which the solid elc.
nents are suspended, is lowered by means OF a rack
snd pinon, worked by a crank, on the battery
ends until the zinc and carbon arc immersed.
From this moment tho positive aud negative wires
become charged with electricity, which only needs the
stosing OF the circuits to send spark through every
cartridge and thus demolish the reef The batteries
prepared are about the perfect ever constructed
or such purpose. The acid bath into which the zinc
and carbon plates arc plunged Is powerful as TO
lct instanancousy on the zinc. which represents the
iuel necessary for the development OF the electric
Energy. Therefore, while the power OF the battery Is
extraordinary, It not lasting for the zinc
consumed On this account the union OF the elements
Will not take place uIti n lew moments be ore the
lime Of nrng when II Is expccted the electricity will
utain the highest state oI tension. TINS lat
qud ,mo sn' %ysrous "nsrg a np'a .onsra', wn'
rcpulsion, nt tho point OF Development
the decomposcd electricity the positive and tho
negative u,ds beng mutually vcpeIlant Tho quantity
electricity developed entirely different thing
from its icnson To explain the difference u will be
development aud gradually reach the explanation
errcd by tracing the connection between each stage
Of the process.
THE DEVELOPMENT OF ELECTRICITY.
inc ce'eornted Gnvan made the first practical dis
covcry In relation to the development Of electricity
while conducting some anatomical experiments IN
1855 He found that by unitinh the lumbar perves
with the crurai muscles or a dead frog BY means OF
sonnectng medium composed Of IRON aud copper
convulsve motion was mpa Ted the irog's leg He
At orce attributed this phenomenon to electricity in
herent TO the frogs body, and did recognize
~ the time that II was due 10 the contact of two
Heterogeneous metals Volta. pcfla a closer observer
OF such matters at once that the power deveI
oped by he metallic union, and invented thcreirom
the Voltqic Pile, which 10 tho basis Of all later forms
Tor developing electricity this principle.
This pile consisted OF alternate plates of zinc
and copper, with intervening ioIds or cloth
Satuvattd with aciduated water This arrange
mcnt OF tho metals produced electrical separation
at once, the action Of the acid the zinc being the
e'ei exciting rsus' he separation oi the CON-
poscn nu'ds nccesstates an energy which The equiv
lcut o the heat generated by the chemical decom, 81.
of OF The metals. Here, therefore. are the
Elements calculated TO produce c,e,t,ical DO
,omposi.on or separation. all OF which
He conductors OF electricity. Now. at tho