The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1868-10-31
HE'LL GATE ORsTRUCTiOys.
NEW YoRK, Oct. 2a, lscs.

To THE EDITOR OF THE HERALD
NY attention has been called 10 an article, signed
"An Old New Yorkeru which appeared IN your
paper OF the 25sh inst, IN which he quotes General
Newton as having stated before meeting OF the
East River Improvement Association, concerning
surveys that have been made OF Hell Gate, Tile
arst was made by Admiral Porter twenty years ago,
the next by Mr.. Davis, and the third IN 1856, by Lieu
tenant Craven. These were only partial surveys OF
the rocks 10 get estimates of the probable expense Of
their moval."
Had this gentleman been a sharp as well as "An
Old New Yorkern he would have noticed that General
Newtons remarks a. that meeting had not been re-
ported verbatim In any paper, but brief synopsis
only given OF their general purporr and that General
Newton could not be held responsible for the literal
accuracy OF such report
What General Newton did say in substance was
that surveys had been made by Admiral Porter, Adj
miral mot Mr. Davis and 10y Lieutenant Craven and
besides these partial surveys also Of certain rocks
to obtain data for estimating the cost Of their re-
mo,aI
San CID New Yorker' asks, "Are there no per-
fected surveys made by or under the superntep-
dence of Professor 4. D. Bache United States Coast
surveyYn II tins person had known as much OF the
history of the operations at Hell Gate the individual
whom he 80 cautiously takes to task he would have
been aware that Porter, DAVIS and Craven were,
while making those surveys OF He'll Gate, officers OF
the United States Coast Survey under Professor
Bache anu that their reports and maps be ong TO
that branch or the service. General Newton sup
posed every one 10 have knowledge OF these facts.
FOR the rest "An 0ld New lorker' Is respec fully
invited 70 read General Newtons report 10 the En-
glneer Bureau OF January 81 1867, where he will
fnd notes of Davis, Porter's and Cravens reports
and maps, as likewise Of partial surveys by Major
PPn ncs " MI Edwards ana OF survey OF rot
upon that rock than subsequent surveys made by
Major Fraser could lind.
IAN Ola New Yorker who seems 0ver-sensitive
and winces where no offence was meant, again
faults Genera Newton with saying, AT that time Il
suppose 1850 the ART OF blasting was In Its infancy
and the expense of removing or, at reefs seemed
beyond the power OF human undertaking." Whe-
tuer these were General Newton exact words or
net Is mmateria; he was speaking or the fact that
previous to tie date OF his report there Is record
OF recommendation by any one to remove the great
reefs Adnras Porter and Davis General TOtten
and Professor Bache have at various periods
mended the removal of the small rocks AS Frying
Pan, Pot Rock, Ways Reef, Shedrake, &c. but
Instead OF an Gtgeapt to remove the great reef called
the Grdron, watch Admiral Davis charac, erizes as.
sowing to The strong set Of the tide upon II the
most dangerous reef In the passagen these officers
had recommended wall to be built upon its channel
margin, furnished with spring tenders to sheer of
vessels, wdich structure would cost by estimate
nearly 81 100000.
Admiral Porter, in his report, recommended filing
up the entire middle reefs with docks and spring
fender, rather than attempt their removal.
These facts are stated to prove that every other
process appeared to these Distinguished men prefer
abe to The expense and difficulty Of a thorough re-
noval OF the great reefs sngy or collectively, and
justify General Newton's assertion quoted above
hgan, IAN c!d New Yorker objects mat General
Newton says 1.-THE subject was better understood at
the present day. The removal Of rocks In Boston
harbor by the drilling process al reasonable rate
viz, 81 40 in currency per cubic foot-has been ac-
complished and this decisive fact was mentioned by
General Newton at that meeting When we consider
the strong likelihood OF great Improvements IN the
process OF drilling and lifting the rock from the
bottom we are led TO hope much diminished cost.
There hes been great deal said about the number
been removed nv the process OF surface blasting but
no details Of Quantities I'm cubic measure) removed
nave been furnished to test tue efficiency OF this
method aud to satisfy public curiosity. Reckoning
the WORK accomplish ned By the amount removed in
comparison would prove. When Pot Rock was al
se,mped by the process Of surface blasting the first
moved by eghynve Charges heT Se n wsle rec
feet In height required 149 additional charges.
porto, required but nifty additional charges Al this
peH9a the work passed INTO the hands of the United
si an n was maq es er
cal H. ght having been removed by this process. as
claimed, there had actually been little over eighteen
seet The bunders OF the previous surveys, as the
error " two and half feet occurred at the moment
when the nat surface had been reached by the reno
val OF salient and projecting portions OF the rock re-
bounced to the great glory OF surface blasting until
they we're corrected.
Subsequently the engineers fired about 300 add.
tiontl charges, and reduced the rock to depth OF
about twenty feet at mean low water.
OF work accomplished, when estimated by vertical
height must provost charges were reported to
have reduced the rock nineteen feet In height put
required 200 additional charges to increase that depth
about foot The inference Is obvious, that the pro-
cess promised great results long as projecting and
salient points were offered to the explosive effect OF
the charges; but a lamentabe falling on took
place when q uniform and fiat surface was
reached. At Pot Rock depth OF twenty
four feet at mean low water was pro-
missed and about twenty feet attained: and, so far
"a known to the writer no entire rock IN New YORK
harbor has been removed by the process OF surface
blasting to the required depth OF twenty four feet az
mean low water, though frequent trials have been
made II matters little what the cause may have been,
the fact believed TO be stated ana until The advo
Gates of this method prove the contrary they are
debarred from claiming that they have attained
certain or even probable success.
so far as known. practical men are strongly adj
verse to the OF this process as eminenty uncer-
tain in the first place. and as eventually leading to
unnecessary expense IN che second. IL might be
partially used however, TO blow on projections and
feye the rock for operations by another mode
After arriving at nat surface the method OF sur
face blasting Il generally efectua only by puverlzing
the rock and reducing t to small Fragments which
indicates q great waste OF power and titne
Tie process OF surface blasting claimed by Mr.
Mailefert was practsed by the Royal Engineers upon
soft rock and il generally asserted that lie learned