Burlington hawk-eye. [volume] (Burlington, Iowa) 1845-185?, 1851-09-25
A visit to aHell Gate" and . blast upon 'sPot
Rock"
NEW York, SEPTEMBER 2,

pos:e Harlem. eight or nine miles from New
York Battery. The East River, or Sound, from
the Battery up to Harlem, runs northerly
course. Here il makes sudden bend, almost at
right angle, and runs easterly for a mile or
more, when it makes another bend northward.--
Between these two bends in the Sound lies this
celebrated estuary, realizing to the mariner all
the dangers and difficulties of the Scylla and
Charybdis, pictured by the ancient poets. The
eastern end of Long Island Sound has a broad
opening to the ocean and as the tide presses in
from the sea, it finds broad channel most of
the way through the Sound, eight, ten, or a
dozen miles wide. When it reaches this neck,
between the two bends mentioned above, 1t Is
| compressed to about half mile in breadth, pro-
| ducing a very rapid, wild current And it is
here in the midst of this rushing flood, that sew
eral rocks and reefs rise up from the bed OF the
river almost TO the surface, and throw The whole
| current into the widest commotion. AroInd,
against, and over these ledges the mad waters
| rave and roar and wnirl with tremendous power.
There is brief cessation of this warfare for
few minutes, during slack tide, at high and low
water, when the giant floods, as if from exhans-
| ton. lie down quietly to rest. Now, mariner. is
| your chance if you have favorable wind, seize
| the opportunity, and scud by while the fearful
| combattants are asleep. Crowd all sail, for that
sleep is short; the tide turns the strife is renewed
and wo betide your poor schooner II you are
within reach Of ..Pot Rock J" sWav's Reef" or
the s:the Frying Pan The most formidable Of
these and the most in the way, il Pot Rock,
which lies nearly midway in the channel To
the westward of this. and little nearer the
northern shore, is the Frying Pan. And Ways
| Reef lies to the southwark OF Pot Rock, towards
the Long Island shore.
Ever since the settlement Of the country the
navigation of the Sound has been obstructed by
these terrific barriers. aud no hopes were eater-
tanned that they woMd ever be removed. To
drill and blast them, especially Pot Rock. was
seen to be utterly impossible; for no vessel or
structure whatever which man conld raise could
be stationed upon il to effect the drilling. AT
length however. few months since, French
gentleman by the name Of MaIllefert, advanced
the bold assertion that he could blow Pot Rock
to atoms without drilling. and clear il out OF the
channel to sufficient depth to render navigation
over il safe at all times Of tide, The idea was
regarded as absurd, and but little attention was
paid TO it. The assertion was repeated, and eE
ldence was produced that NJ. Maiilefert had al
ready performed i similar feat at Nassau, New
Providence. where he had. without drilling.
blasted and removed nearly a hundred tons Of
rock eighteen twenty feet under water. NJ.
Maillefert fered 10 undertake the job of remov-
ing Poi Rock. If the means were furnished TO
carry on the work. stipulatinr not 10 receive a
dollar for his own services till the work was
fully accomplished. Some interest began to be
| awakened upon the subject. and al length HEsHY
| GRNNELL. Esq, whose lberaity in AID of hu-
name and public enterprise is so well and widely
known. subscribed five thousand dollars for
commencing operations. Assurances of aid
were obtained from other quarters as fast a.
there should be any evidences Of success, and
the enthusiastic FrenchG!an went 70 work.
His mode of operation is to sink tin canister
| OF powder down upon the top of the rock, and
there ignite il through wire by means of gal
vanic battery. This is performed during the few
minutes of slack tide at high ,edier for the deeper
the water the powder the better. BY the
expansive force Of the explosion the large mass of
water above and around tnnst be instantly remov-
ed. lifted. Bat the motion of all matter requires
time. The expansive force is created instantly
by the explosion, and exerts itself instantly in ey
cry direction II will not willingly wait for the
slow rising Of the mass of water high enough TO
afford 1t relief. II therefore makes its way al
the same time downward upon the solid rock,
crushing. crumbiiny, and grinding it to pieces
Ali matter. as far we know, il porous and
| compressib,e, and rocks are more compresslbie
than wafer.
Philosophy should therefore teach us that sud-
den expansive force between body of water and
| body of rock while it requires Time to remove
the water, mist necessarily 10 some extent crust,
the surface of the rock. if it is too large or too
! much confined to be removed in body. And
this has proved to be the fact By every blast which
NJ. Maefert has made. AT high water the top of
Pot Rock is now eighteen feet below the surface.
After blast, it is found TO be covered with brok
| en- fragments, some of which are grapped and
taken us. One piece was taken up yesterday
weighing two hundred pounds, and carried TO the
| civ The next rushing tide sweeps the top of
the rock clean: and after the next blast it is again
! covered with fragments. There have been now
nineteen blasts. seventeen on Pot Rock and two
! on Ways Reef. Not one has missed fire, and all
have done execution. The blasts were commence
ed with sxty-two pounds OF powder, and in
creased afterwards TO eighty-seven pounds, and
L., Lr,,.l r.l M
five pounds. About fourteen hundred pounds of
| powder have already been used, and many tons
will doubtless be required before the work is
| completed.
went IN to-day TO witness the oper ,tion Of
blasting. A considerable number of spectators
lined the shore near the village of Astoria for the
same purpose. Lieut.. Washington \. Bartlett
of the U. S. Navy. was present, aiding and as
sstng the operations, having been detailed by
Professor Bache. of the Coast Survey. 70 come
and make a survey Of these rocks, and observe
the progress of the work and the changes pro-
duced in the currents. He has partially survey
ed Pot Rock, taking the depth of water upon its
length, but not vet upon the cross sections. The
top cone of the rock has been knocked away and
lowered four feet, there being formerly eight feet
of water upon il at low water, and now twelve;
that is previous to the two blasts to-day, the ef-
feet of which has not been ascertained. BIT al
the work descends. the surface of the rock to be
the rock now at low water is twelve feet. and the
length Of the rock about twelve or fourteen. Al
depth Of seventeen feet at low water. accord
ing 10 observations Of Lieut.. Bartlett, the leng
. Of the rock will be twenty feet; at a depth oi
twenty feet the length of the rock il eighty feel
at depth Of twenty-foar feet the length is hTn.
dred and twenty-five feet; and at depth OF th:r.
ty-two the length is a hundred and fifty. To Oh.
tain the last mentioned depth of water. therefore
. | vast amount OF Rock must be removed.
, A couple of Francis's life boats were there
furnished g-atutouslr by that gentleman to all
: the work. A large floats anchored in the chan
mel about eighty feet from the rock. About
dozen of us, accompanied hy Lieut.. Bartlett
: went ont in the ife-boats 10 the tloat, 10 have
near view OF the ;plosion. Precisely at higl
. water, there being but three four minutes ces
sation of the current, the large tin canister j
: carried from the float and sunk upon the top o
the rock. The boat returns 10 the float, bring
iny the end of the wire attached 10 the canister
Mons. Maillefert attaches the wire to his batter
and completes the circuit. INSTANTLY report i
hea ii. and the mass of waters over the rock ris
into the air. There seemed to hc Il solid body u
I water. PERHAPS twenty feet in diameter rising Z
: a.heigh' of fifteen or twenty feet, AM, then tow
, ering up in broken fragments and jets twenty o
thirty feet higher. And il ever the deep did Iii
/ orally ''bol like pot,' it was in that portion o
it that moment lying over Pot Rock. The effec'
,cEn Ill e. hat H., -