Eastern times. [volume] (Bath, Me.) 1846-1857, 1851-10-02

formed during the lew minutes OF slack tide
at high water, for the deeper the water over
the powder the hetter. By the expansive
iorce OF the explosion, the large mass of wa
ter above and around must be INSTANTLY re-
moved, lifted. But the motion of all matter
requires time. The expansive force is crea-
ted instantly by ihe explosion, aud exerts it.
self instantly in every direction. 1t will not
willingly wait fOr the slow rising of the ma IS
of waters high enough TO afford il relief II
therefore makes its way downward upon the
solid rock, crushing, crumbling, and grinding
IL 10 pieces. All matter, as far as we know
Is porous and compressible, and rocks are
more conpressibIe Than water. Philosophy
should therefore leach US that sudden ex-
pansive force between body of water aud u
body OF rock, while il requires time TO remove
the water, must necessarily 10 some extent
crush the surface Of the rock, If il is too large
or 10 much confined to be removed in body
And this has proved TO be the fact BY every
blast which NJ. Mailefert has made. Al high
water the top of Poi Rock is now eighteen
feet below the surface. After blast il is
found TO be covered with broken fragments,
some of which are grappled and taken up
One piece was taken up yesterday weighing
two hundred pounds, and carried TO the city
The next rushing tide sweeps tire top OF
The rock clean; aud after the next blast il 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 execu,on-
The blasts were commenced with sixty-.wo
pounds of powder, and increased afterwards
to eighty seven pounds, and the last blast tu.
dav was hundred and twenty-five pounds.
About fourteen hundred pounds of powder
have been already used, and many tons will
doubtless be required before the work is
completed.
went up to-day to witness the operation
of blasting. A considerable number of spec
tarors lined the shore near the village OF AS
torla for the same purpose. Lieut.. Washing
ION A. Bartlett Of the U. S. Navy was pres
ent, aiding and assisting in the operations,
having been detailed by Professor Bache, of
The Coast Survey, to come and make survey
ot these rocks, and observe tile progress of
the work ard the changes produced in the
currents. lie has partially surveyed Pot
Rock, taking the depth of water upon its
length, but not yet upon the cross sections.
The top cone OF the rock has been Knocked
away and lowered four feet, there being for
merly eight feet of water upon il nj low wa
ter, and now twelve; that is, previous To the
two blasts to-day. the effect of which has not
been ascertained. Blu; as the work extends
the surface OF the rock TO be blasted becomes
more extended. The wafer on the rock now
is twelve feet, and length of tile rock about
twelve or fourteen. AT depth of seventeen
feet al low water, according 10 observations
OF Lieut.. Bartlett, The length o: the rock will
be twenty feet: al a depth Of twenty feet,
the length Of the rock is eighty feet; at
depth Of iwenly-tour feet the length is hun
dred and twenty-five feet; aud at depth of
lhirry-lwo feet the length is hundred aud
fifty. To obtain the last mentioned depth of
wafer, therefore, u vast amount ot rock must
be removed.
A couple of Franciss life-boats were there
furnished grauitously by that gentleman TO
aid the work. A large float is anchored in
the channel about eighty feet from the rock.
About dozen of us, accompanied by Lieut..
Bartlett, went out in the liie-boais 10 the float
| TO have near view of the explosion. Pre-
cisely at high water, there beng but three or
four minutes cessation OF the current, the
large lin canister is carried from the hoat and
sunk upon the top of the rock. The boat re-
turns 10 the float, bringing The end OF the
wire attached TO The canister. Nj. Mai lele.t
attaches the wire 10 his battery and completes
the Circuit. Instantly q noise is heard, and
the mass OF waters over the rock rise into the
air. There seemed TO be solid body OF wa
ter, perhaps twenty feet III diameter rising
TO height of fifteen or twenty feet, aud then
towering up 10 broken fragments and jets
twenty or ihnty feet higher. Aud if ever the
deep did literally ''boil like pot it was in
that portion Of il that moment lying over Pot
Rock. The effect, after all, was not terrific,
but beautiful.
M. MaiIletert is preparing to drill on Ways
Rect a five inch hole eighIeen feet in depth
and give il blast which will probably do
great execution. Il is announced, also, ihal
the Malleiert method is to be applied in a
week two TO reef between Governors
Island and New York Battery. Ltelhgenee. j.