Morning herald. [volume] (New York [N.Y.]) 1837-1840, 1839-09-04

quantity of old metal. Such is 10 be the nature of
the work where the aqneduct crosses Manhattan
valley.
After this, however, shall see little nothing
OF it, for the whole length oi entire section for the
instant il energies from the last chamber, II enters
mixed earth, brick, and rock tunnel, 700 feet long
which Terminates about the centre OF section 92
After this the only thing visible for about 1000 feet
will be low shapeless mound or ridge ofearth, mark
ing the OF the aqueduct, until come To about
the centre af section 3d. where again another
tunnel. from which II energies snly to be in the
raised work at crossing Clendenning valley depict
ed the extreme right of the upper part the above
section. The raised arched work at this part Of the
aqueduct extends 800 feet, and six streets,
all of which will be graded unsvenly-no two on the
same level-again giving grotesque appearance Is
the work.
The syphon here intended ia be employed will be
the largest that constructed in any part Of
the world The only syphon AT prescat In existence
that can be compared with that OF the Croon, Is the
now in use near Genoa, which extends distance
Of about 1909 feet, and has been built within the last
100 years. Ii has usually been supposed, and BY
some writers very confidently stated, that the Ro.
mans were totally ignorant Of the mode of convey
ing water by means of syphoas, or tunnels. That
this is not true with respect To tunnels, have al
ready shown; and that they knew the Of sy.
phous is proved by this passage in Pny, 81 s $ 81:
"Aqua in vel plumbo subt altitudinem exortus
sui Water in leaden pipes rises to the height of
its source But the fact is, that altheu .h they made
frequent Of pipes (fstuta) in conveying water,
vet pipes would have supported the weight Of
water conveyed to the city by the Roman aqusducts
But we have a still better proof than this The
Roman aqueduct that built carry water to
Lyons, in France, (the ancient Lugdunum) had
syphon in part OF its course. Near 10 st. Irenee
on the heights, there was placed large
ervoir; hence the waters flowed in eaden pipes,
which descended into the fosse of St. Ircnee,
and passing along the bottom Of il, rose again, and
emptied themselves into n reservoir, built a
spot which can be traced in tie wall. OF the city at
the Walt of Fourvierc, above the gate Of Trior,
the south side of square tower. These pipes
cd MS itch ap1va all
bridge (as has been stated BY writers;) there
not the least vestiges of such a work neither
were they carried over in the patchwork manner in
which the syphon at Manhattan Valley is construct
ed but they were properly bedded n solid course
of masonry. The nine leaden pipes through which
the water flowed had each 3 inches diameter in the
clear; the thickness Of the lead of which they
composed was about ono inch. These syphon pipes
after having descended about - feet, each div lded
itself into two branches and thus the waters were
carried the rest Of the Is pipes, until they
again the opposite side to height OF about
10 feet, at which point they again united, and the
waters passed aad entered the receiving reservoir
in only nine pipes.
Besides the location Of the line Of the Croton aque
duet, from Manhattan Valley TO Clendenning Valley
the above drawing presents five different portions OF
the work, marked A B G.. ID T. which may thus
be explained. The drawing A is a section Of the
stone work supporting the aqueduct across Glen.
denning Valley, the height OF the work 10 the top Of
the arch of the aqueduc is about 80 feet the width
Of the grade line at the base Of the aqueduct ARCH
point 10 formed battering dowRwards on a scale Of
an inch to foot. This work il formed Of large
pieces OF stone laid together without cement, except
on the outside, which presents the appearance Of
well hammered stone masonry; similar In its chzrac.
ter To the external appearance 81 the church OF the
Messiah, only the bl cks of stone are larger than
those in that building. The view marked B. is
section Of an earth tunnel, or description Of work
which frequently occurs along the line ri the
squedset In this view the diameter Of tsc conduit
locks larger than that at A. but II is precisely the
- e. L A. r. -
in diameter at the span of the arch; the arch itself is
all OF simple brick, and therefore objectionable, and
liable TO spring considerably; the sides and spas
drcl backing of stone, instances cement
ed, and m some not, the want OF uniformity again
prevailing. And along many parts of IN. line much
81 this brick work has given way, and has to be
built.
The view marked & represents the outside OF n
protection wall (of which great deal has been said
By IN the course Of our articles upon aqueducts)
This view represents the aqseduct crossing a dell
rzvne, through the bottom of which runs a break
or water course. AT the bottom Of this foundation
wall, in the centre, rs seen small oriice called
culver which is made for the passage &c the natural
water courses Of all the ravines, which IL damned
back by a flush dead wall, would in very short
space Of time sweep away the aqueduct On the
top OF this protection wall the sloped covering re.
prcseRts the position Of the conduit aqued tun-
mel; Immediately under this, a little more than its
extreme width, down TO the bottom Of the ravine,
foundation wall is built up solid to suppart the
conduit. precisely similar in is character to the
section marked A; with this exception, however,
that in crossing ravines Under ordinary srcumstan-
ces the outside Of the foundation wall s not finished
so smoothly, because between il and the protector
wall there generally mass Of earth vary ing from
20 ia 20 feet in width.
The view marked ID represents section of q tua-
sci in a rock cutting. This opening il about feet
high, (arger than mest,) but al the same width zs
other tunnels there is very little spandri back ing
required in ths part Of the work. although the sides
all built with outer OF large stone and an
inner facing of brick, with an inverted arch (the
size inches) and two feet Of concrete beneath this
The roofs in these tunnels not formed er brick
arch, in earth open work tunnels but is formed
BY the original body 81 the rock in which the tunnel
is cut. But the sides made ana built M water
tight ab.ve the water line of the aqueduct and even
up Ia a height &C seven feet IN the clear The view
marked is properly termed gate chamber, for re-
ceiving water from the common aqueduct; this cham
Der is % feet wide, and the main walls 10 form sort
II reservoir, ten feet high from which rise high
side walls, and over these VIII be placed a cupoIa
roof From such chamber az this, the water will
he carried straight across Harlem bridge. and in
syphon from across Manhattan Valley in four iron
pipes 81 three feet in diameter placed side by side or
as above represented.
modern aqueduct in various sections "a the same;
and an analytical mind will al once sec hat the
whole arrangement Is bad IN its general feet and
defective in many OF its details want &c harmony
and uniformity pervades the Whole; and what il
still more TO BE- lamented, IL Is feared that when
completed IL will sot be foun lowing o. shameful
management the part Of the water commissioucr,)
capable of answering the purposes for which IL will
L. -. Lao -. -.