New-York daily tribune., 1859-01-28

i, NJ ade for the Q feet lees lead Of wster) to the
.mbanhme,t in progress around the new reservoir.
The distributing reservoir on Murray hill has
two feet greater depth Of water than the new re-
se,voir around its edges. Standing upon the
etreets. it is built within 10 outer double shell OF
masonry. which serves to hold up the earthly wall
,hs. ,eeaips the water. An outer wall, with
batter of in s, is built up feet thick. Twenty
feet within this s an iurer, vertical wall feet
thick. the two connected together with cross walls
If . feet thickness. arched over with brick at the
HIGHT Of 35 feet. sud 10 feet below the coping
The atone is laid in cement; but If with any ex-
peotation of preventing the teriDgo OF watsrthroush
the walls. the incapaciy of the work for this pur-
nose is shown BY the rsinwatsr that falls upon the
coping finding its way through tue outer wall and
dripping continually afser rains, into the street
Even with the head of only III feet over the con-
crete laid upon the extrados OF the orlck arches
and the masonry between them, it thus penetrstes
the stone wall. The embsnkment within Is .uen
earth As was found on the spot rolled or rammed III
LAYERS from the bottom up-and In this mater'sl
clay was probably not large Ingredient, for II Is
believed to be scarce in that locality, and the az
counts preserved of il speak OF earth only without
particular mention of clay. This extends from the
bottom, risirg feet in 10 feet horizontal and
mon il is laid course of concrete one foot thick.
From this the principal slope of the embankuent
rises at the steep angle Of 45, or base to YER
teal The whole thickness of the pudded earth,
at feet above the bottom, is 33t feet; at ~ eet
below top water line, % feet, and at ~ feet below
II feet. At the water-line the stone pavement oi
Is inches thick, laid in cement, with which the
embar kuent is faced, meets the coping. From this
account L is apparent that the distributing reservoir
is Lot 80 veil constructed TO resist filtration oil
water, ard the loose ming effect to the emoankment
that would follow, as is the new reservoir; ana
yet it is exposed to greater pressure We are
not aware that any fears have ever been enter
t,ned of its stability if So its history must quiet
them. II might be added that, beside the great
thickness Of the embankmen', amounting to about
100 feet at base, of packed selected material,
larger quantities of waste material are accuml-
lated on the outside of the high banks, where, IT
ever break could occur, its effects would be the
most DISASTROUS The precaution appears to result
from an excess of prudence for, in the history OF
similar structures, we are not aware that ease
has ever occurred Of still water breaking through
barrier of this nature: though case is on record
of the .'Dlke BertLaud" being cut down on its
outer side by the force of the waves breaking over
its top, and coming violently down upon the external
edge Such consequences are guarded against, as
before observed, by the hight of the inner slope
wall.
| Propositions have been made to introduce ma
terial change in the structure 10 the form of aver
/ tis al wall of concrete in the place of the CEN
/ tral puddle bank of day. The French engineers,
it is seeu do not esteem concrete any more iroper
vious and the thickness OF the proposed wall is not
sufficient to add materially to the weight and sta
! bty of the structure, while its position conceals
il from examination and places it out OF reach OF
repair. No certain advantage is gained by its
adoption, while greatly increased cost is unques
tionable. Enormous quantities Of hydraulic
/ cement would find market, aud the manufac
| turers of this article, We imagine would be the
principal parties benefited by iEsuss in this way.
! If additional protection be the real object Of
]
these persons will be assured by experienced en-
sineers that this will be attained more simply
ehespy, and certainly by hattening the slopes of
the entertainments, than by concrete wall; but
even this they would probably fail to recommend
IL is 10 be considered that this emb .nkment is not
a structure that can be moved BY lateral thrust Of
"a feet bead OF water-that it is always under in
spection-tba. injury to it from any ordinary cause
can always be remedied at once, and that, should
necessity require, the waters can bs rapidly drawn
down through the waste gates We can Imagine no
cause of serious injury to the embankment without
the concrete wall, to which that containing il
would not also be exposed; an earthquake would
prove equally DISASTROUS to either, but, happily,
this is q catastrophe which our engineers are not
expected to plan against in their works.
! FROM WASHINGTON