New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1866-09-22

FORMULA Foa CALCULATING THE DISCHARGE fRoA
SEWERS.
from Sewers but the following is one OF the most 6nPi
1t is also substantially correct Ascertain me hyGlau
mean depth when the sewerage Is san de IN is one
fourth ofe diameter Of tho pemeer II the sewer run
ming full if it is not full it is the section area aIld W
the wetted per meter. The Heted pemeel IL thae P'
o The sewer weed by the fluid. The fall in feet per iie
is easily obtained by measuring 100 or 5VJ iect ahq ccu
lating The fall Of 5Sc feet Having go' Use 81 s o.
feet Der mile and take out the square root multiply th,s
by S. and the result by the section area The Product VIII
be the amount in cubic feet per minute.
SEWER COMM CTl0Es.
We have already inimated the importance OF this part
of tho sewerage of cities 1t is BY means OF sewer con-
nectons that houses are Drained so that ever noose
owner and every tenant is Immediately interested IN inc
manner in which his refuse is delivered into the sIeet
main We have spoken of the size, shape and grade OF
sewers tie fall and velocity Of sewage, and given
formula fr calculating the discharge. Now we give few
general principles which house drains should be lad
Ii is Of great Importance that connections should DC maze
as tho top of Mains and the curves should nave as
large a radius as possible Indeed these two rules should
be mpemtyely insisted upon. The principle upon which
sy are based is obvious The resistance Glminishcs as
tho radius of the ia increased and when tho mouth
Of the drain Is above the level Of the sewer retrogIade
movement Of sewage IN the latter will not stop the iow
from the former The minsfing of currents sometimes m
pedes their fow and 10 avoid this il the mouth oil the
smaller drain be made in the slapo OF bell the oonnec
ton solid and oven and the rules have given adhered
to faithfully tho faults Of construction VIII Dc reduced 20
minimum. III, on tLe OlncI manu-, INC
the friction of the passage Of sewage be great the auGs
will pass while the solids remain, thus making in little
while eiioctunl bar 20 their progress PIPE sewers
should rest on hard wefouBCd bed, and the tail should
be as regular possible without sudden differences OF
level This is general rule concerning grades while tho
radius Of should never be be lees than ~ times tho
cross sectional diameter Of the sewer.
CAUSES OF FOUL SEWERS.
The principal Of foul sewers have been suggested
in what have already written, notEl hsanding The "c
that the subject has been very Superiority created lJ
may however Dc grouped thus; Bad ues end gradcs
g imperfect form ard workmanship 8, excessive hicton
bad porous materials which absorb Tho fluids OF alow
them 10 pcrcoatc 5 insufficient water supply T. the do
which forces back the sewage, ard imperfect traps ana
cor1cctio-s combined with faulty caCh-tasins and badly
CONTRACTED ma1-holes II Is extremely difficult to Keep
sewers ccan end for this reason they should always be
built SO m cleanse themselves Tie amount oil water
required for hs purpose supposing thcn 10 be pr perry
constructed 81 every respect should not be less than .
gallons for each person daily In addition 10 the rain fl
" tie gladc is slight the amount should be more Ia ad-
dtOn TO this the sudden passage OF largo bodie o WAFER
through the sewers Is often necessary and shoud be en-
poyed on the ground already stated that the moro water
they receive the better.
xAS.uoLEs AND cATcH-BAaNs.
MsnbOles arc constructed SO 10 allow persona 10 de-
scend into tho sewers Thcy are built wherever there
sudden change Of grade and are used FOR me OF
removing the sediment matter which iailH 70 DO us-
charged. Cachbasins are buit at Tie ooneis OF tno
streets for the purpose Of taking mp tie
end are 20 constructed 20 admit the wnshnfs ron ue
paycments and retain them IN the bottom who Tue Nte
fcrucly raised 10 The surface ard carried away. The
oatch-basns act yentntors and chambers have be-
sometimes PLACID b. the side Of the maE-holes ior ue
ZANE purpose These made o. receive the sewer ar
after Il had passed through horizontal or vertical CHARCOAL
tiays by which 1t dCodo,izcd and purified; but We
believe have been used in this country All modes
Of ventilation imperfect; and not aware OF any
trap yet invented which thoroughly prevents the escape u
e mephc gses always generated in sewers The effort
il shut the cdOr up in the sever but very little success
has thus far been achieved
TIg ROMAN SEWERS.
The sewers OF ancient Rome called clo0cd,, and
rirafa oil nv
foundation OF tic city, for the purpose Of dfaDAg We
marsLy ground between tho Paatne and Capotlne hills.
Tho trunk DRAIN called clodoa Marina is formed by tre
tiers Of CoRceRr0 arches everything each other IL contact
The whole work 10 feet wide by 80 feet IN hight ana inc
masonry is Of hewn sOno laid without cement AgnlTa
sailed through tds sewer in boat and Nero caused his
victims 10 DO thrown into II. Along this suberIaneaa
channc the drainage Of the CITY wei az the surplus wa
teTs Of the aqueduct discharged themselves into mo
The cleansing and repairing Of the oOoeae were conhded
10 tho ccnsOs but aorU ad commissioners were appointed
for the purpose who employed c0nyc5 IN the Work ana
levied tic expense by assessment Tho doa,de yeI serves
n part for the drainage Of Rome and include not merely
the immense vaults by which Ito drainage Of the cSien-
al marshes abOut tbs city effected, bui also tho wood
en- pines clay tubes aud CIans Of Whatever kid by
impurtes were conveyed from the houses into thoma
HE principle thus early adopted by tho Romans
undcrlics the drainage OF modern cities and "Ls ana
although many improvements have since then been made
in the construction OF sewers, try yet y, and con-
tnres elapse before what known concerning
ein will be fEuy applied 90 older cities and towns.
TIE SEWERS OF PARIS.
After what has been written BY Victor Hugo concerning
se sewers OF Paris would be useless TO attempt their
description For present purpose IS merely neces'
sary Ia state OF two facts In connection Win the
Tho great surrounding tho city, known as the egoHi
d ccfpfure was lut In h. for tie purpose Of draining
the valley q tho Maais Menlimonaht ana MohtaItre
and from thai time the Central Government mas exercised
through the Department OF Public Works, an active con-
troll over tho system ~ sewerage The present EmleIor
NJ ring forward works OF this Kind with great energy.
connected network If Hldcnuus the ey on bOh
sides Of she Seine, which discharge their contents mo inc
river at ARrieres, through grand trunk sever ~ Icet
,1, Jfrt lgrO In
Sewers made viii paths each SIDE just ABOVE Tie
stream. A tramway runs on one side, which carries
machine which can a. once clean the bottom Of the sever
Tho entrance OF each hOuScdn is marked ~ porcelain
plate bearing number ard the Of the house pays
thTee francs annually to have his house-dn Kept eean'
| TIE SEWERS OF LONDON.
The drainage Of London provided for by legislative
enactmens commencing In l22j but the whole subject
was thoroughly revised By Sir Thomas More in bill
passed IN l53l he use OF ire sewes N tonGoh
until the present century and during the reign OF Geoge
III act passed prohibiting the discharge o. o'Her
matters into them, under the penalty OF hne. Inc H.
yenon Of wsterclOsets I'D 20 new use Of the sewers,
and their capacity taxed TO an extent lot at oil CON
tempated in ther original construction The refuse mat
ter Of cesspoo umed into the Thames, poutng us
waters while the covers themselves incompetent 10 dls-
charge their increased buIeDs became avenues OF inc
most poisonous gases, which were discharged into the
street. II became necessary TO construct the sewers
upon larger scale and better plans They were then ad
upon regular system coming down 70 the nVer ron
each side for distance Of six miles along its course
Their total length exceeds 1900 miles and tho principal
sewers are Of extraordinary dimensions Those known as
the Fleet ditch from u to IA feet high and o. feet
wide. The Moorfehs sewer 10 81 by feet and
at the mouth 10 by 8 feet; st the north enc OF
| the pavement 1t Is feet below the surface,
The more ordinary dimensions, however arc Of the
largest size Of ttoIevse pipes Of semicireuar sechon
upon diameter Of feed; and in brck-work OF egg,
shape feet3 inches in hight by feet IN width and
feet and by s. by 81 feet The NEST serious difficulties
from this drainage system Notwithstanding It's meg
nifcen proportions The outlets OF the sewers In order
10 get sufficient fall for discharge, were but little above low
water mark and consequently the sewers were closed by
the tide except Tow water BY this means their gaseous