The New York herald., 1862-04-20
NATIONAL Cadets,
slxry-sl1u IkeINsNT \. Y. 5. NJ, CosPASY c, ,
The New Harlem Bridge.

DESCRIPTION or THE SfLUCrURIs-MECHASICAI. EE-
FECTIv OF THE WORK, ETC.
The IIarlen Bridge, now In course of construction,
fast approaching completion under the body con.
tractors who have ii in hand. large body OF
employed daily upon It, and, when completed, which it
s expected to be in short tuio, tho Harlem Bridge
will from all present appearances, be of the lacs
structures of it's sort in the country The following
tho officers at present IN Charge OF its construction and
better or competent body of gentlemen could net
be selected for the work.
Conmi Judge Robinson, Alsop f. Lockwood,
William Miner, Joseph Westvcrth, James Davis.
Contocor--John Roach.
Supsri.,, stent--)ameS Hough
Csif Enoner--Erastus W Smith.
Assistant ErgasersThoophl SckCs, Lshan Rogers.
The whole affair is being onergotcally pushed
forward and undcr the efficient suporateadence the
above mentioned gentlemen it is expected that the work
viii be- shortly completed Several OF the columns
already in position, Mr. Charles V. Hough having prn-
cipal Char ge OF this department.
The following is "a description Of tho wholo work.
The total length Of bridge between abutmonts which
to b. Of stone masonry is 4G8 feet ombr acng four
openings and, of course, three piers lhe central pier
is for draw AMI is composed OF twelve columns OF Cast
feet in disnotef, eleven Of which arranged
In crclo I nifty foet diameter from outside TO outside
Of columns, ard ono si;uated in tho centre These
columns sunk to different dc; tbs, varying from ATTY
to Glty eight feet teG. high water, AID flied with
Concrete. The depth OF water 1t high tide
thus piar IL twenty feet tic bed OF the river being
composed a large bou!d,rs and coarse gravel which
nd for depth or six fcot and thence the foot
OF tho columns the material was sand bong finer as the
dept increased, until at Il h OF iy.,gLt feet IL
apItoac nearly 20 qlt ksanl Tho co:Imit
posed or cast iron cylinders nine feet oEy and two
chs thick with anses on tha inside, at each end by
which they bolted together This pier ID lnishsd
and IL nougted with u ca,i-iron circ.r gl;der to
ceye the turnable track. Tho intermediate pit
be comp sed each o! Ave columns arranged
In q line tue two oatste columns eight feet in Diane
ter. and Tho three Inside columns six feet in dame
te. The six feet columns sunk, and
tnerc remain TO be sunk the -four columns
cipn di1rn1ter. lhe depth water and CI1ruc-
ter Of river bod similar to the draw pier The first
column was sunk in January, IS6fyynd the last In
March, 1867 Ba:wecn these periods the work Cf silk
mg co!urars was suspended at yarcus times, ior
periods varying from lew days to Ave weeks and tho
time actually ent in sinking any one column varied
from live weeks TO iorty eight hours. The time first
uaIncd ioped ny encoGnci Ing largo rocks III
tho bed cr the river Immediately under the location Of
o. the columns and the ant OF knowledge the
hest N IcmON ing them; ana the shorter time
the Ssqu, e acc 'Mulaed experience IN the Work
and The absoncl of any largo rocks in the river
under tho column; and where obstacles Of this
or Ike nature arr it is fair measure Of
time which wo.!i be required for the sinking of
clIian The sudii ahutmeat is bnilt TO above high
water mark ,sd Is cuminsrd W LARGO blocks of bno
stone faced wii 'hnsc On each side OF The b. idge
thorc VIII Hths 81 stone steps In the abutmsnt,
d.sceudh g. .,W water mark The supcrstructaTe
will be wholly Z n. The mai, supports of the bridge
90 be 0onoae1li wrought iron arched hollow tubes
81 huitg the opening and tied Ut their feet by heavy
rc . rnon which rest tho iron floor girders Tho foot
w,s each side win b. supported by cas-, iron arches
ara viii b. feet in width, the roadway being
tu eight feet wide Tho draw vi i'll bo the heaviest
e,sr nsiruo ed, but will bo opeaod and closed rapidly
by shc application OF the power of Croton wator under
pre- sure.
Yesterday afternoon tho BRIDGE ps far as completed
was thrown open the public for Inspection and
hsd expressed their entire appreciation OF the pro-
gfsss made towards its completion.