New-York tribune., 1873-12-13

N turn its now But this is not all The fall oil
tho branch IA three times great as that OF the sewer
conseouently s must be more rapo' anu 'S 'oiuo
proportionalIy greater For the purpose VI ascera"
ing the sum Of the difference on inc ioies"'ns
bases will suppose a cylindrical sewer W w S'''
tuied for the natural bed OF the prauon' ""ps
sectional area OF I72 square ee equal only 10 una. Oh
the Aneust fowl which will require diameter OF ifS
feet and make ,s length $500 feet. the same az tno
length Of that section OF the six .fee, se"er'
Water flowing through such sewer ''o
feet in length, 14s feet in diameter "''
having all OF one foot IN 100, would have FeiociS ~
i923535 feet per second and M volume per second "ou
be $500 32O9 cubic' feet which is sixteen times ~ ere.
as the volume or capacity Of the sxeet sewer, with ia
OF only inches in 100 feet Thus the sectional area Of
sixfeet equal 10 2s27n square feet the yeiocy
of It's ow undeE the head named Is 0 feet per second
which will discharge volume OF 19992s2s2f
cubic feet per second which, as before stated
is equal TO only about l-lGth OF the VOL
ume 10 be intercepted. Hence, considering all
the conditions involved on the basis named,
II would require an enlargement OF the sx-feet inter
ceptnQ sewer 10 diameter OF 1873 feet, with sectional
area Of 263O22s square feet through which tne now
would be at the rate OF 1850 feet per second ana as
charge volume OF 32is06G0S7i cubic feet per second
In other words safety requires that the sxeet part OK
the boundary sewer which has been laid shall be taken
up and one feet diameter substituted. and
that the lower section shall enlarged
When that Is done. the Tiber arch between Maryland
ave- and. North CaptoIst. may answer, but all above
this section will not answer large proportion OF that
in the vicinity OF Seventh and Rsts Is In very bad
condition. almost entirely choked in parts OF IT, That
too will have TO be taken up. or enormous sums VIII
have 10 be expended in repairs aud additions
The B-st and Mssourave. sewers, substituted Tor the
canal are still more deficient than the boundary
sewers and these are far more dangerous II q real
food should while these remain In their present
condition, all OF the canal valley from the Capitoi 70
Sixteenthst. must inevitably become so deeply sub
merged iii all the cellars and Easements within that
range including the Botanical Gardens and the water
would q depth of two three feet On the first
floors OF OF the stores All dwellings. In support
OF these conclusions will say that the first effects OF
the August rain OF only nch but falling ini26 min
utes, was TO Ill nearly all the new sewers 10 their
utmost capacity, and to cause many OF them
to overflow and food numerous cellars ana base
ments IN localities never before reached by the
greatest floods, when the volume OF the water was
certainly third il not onehah greater IL hled all
depresons of the ground to the surIeeeye Of the
adjacent streets and parts OF the streets the
water the surface 20 the depth OF two ana three
feet That brought the OF the eastern hall or
the B-st. sewer several feet under water which so
obstructed the flow from its branches az to cause the
water 10 set far elevations OF eight and ten feet
higher than the tideleve by which numerous cellars
were flooded Just as predicted my former commnnici-
ton TO THE TRIBUNE It produced similar effects on the
MissOuriave sewer and the cellars and Easements
connected with its branches IN localities never before
reached by the greatest floods All Of these damages
resulted manfestly from the inadequate capacity OF the
Bst. and Mlssouriaye sewers unwlsey suosttaed ior
the wide and spacious canal.
The Tiber arch, extending from Mnryland-aye. 10
North Capitost length Of nearly 1900 feet with the
bed OF upper end than feet above the tide
level filed 10 Oyernowng through It's entire lensth
and at its upper end the water thirteen feet HIGHER
than its bed, thus attaining hight OF twenty
feet above the tide-leve IL had just begun howinS
over it's crown and the surface OF the
streets when the rain ceased falling, thus show
ing that the water at that point must have risen
thirteen feet in minutes This leaves no room
for doubt that IL the rain had continued falling AZ tue
same rate few minutes longer lt would have rolled IN
torrents the surface OF the streets ani at the end
OF an hour it's volume and force would have become
irresistible and fearfuly destructive OF life aud property
including the inundaton Of the canal valley as before
described
Similar effects were observed all the city, all evil
IDENTIFY arising from inadequate capacity and bad con-
sructOn OF the sewers And 1t has been 30 IN pro
portionate degree whenever there has been bu; mod
crate freshet. In this the soil OF the city, az well
as the cellars has been kept damp and foul with sewage
and its noxous gases to such an extent as must, IL
would seem very seriously affect the general health.
For it Is well established scientific fact, that undue
dampness of the soil causes consumption, ana that
proper drainage will prevent IL. A damp house must
necessarily be unhealthy. but when, ordinary damp
ness foul sewage gases are added the effects deadly
in numerous other forms. Aud this il Just what the
Board of Public Works have Inflicted upon this city 10
such an extent as calls for immediate and most earnest
attention on the part OF more Intelligent men Win
whom obbcry and plumber are not leading objects
have before said the size of the lower section Of
the Tber arch will do provided the boundary intercept
ing shall be enlarged described to something
over 1s feet in diameter; otherwise. But 10 this
must be added important proyiso viz that it sha
not be extended at the size from MARYLAND u
vrgniaaye., as provided in contract now suspended
A conclusive objection To this extension thabit is on
dead level. while the 5000 foet between Il ana the
boundary fall OF 1915 feet, from which the water
rushes with such great velocity a. mnst eVabv Or AK
up some part OF the sewer II ITS now ne cheekeu y
confinement long stretch OF level sewer OF tue same
size ., ,--...
all the faults, and bunder ot the oaru
brought by earnest, honest, aud fearless SPECIAL
Committee OF Congress- composed OF members who are
not connected with the transactions OF tho
Board They would believe, discover most stalthhS
frauds punderngs, false measurements ana cODIpu
tations end OF bad work on streets ana sewers ana
enormous sums allowed as extra payment. An instance
B-st sewer seventh 10 Ffteenthst, when II was
contracted TO be done for $4,000. They would hnd nu'
merous cases OF this and even worse character.
Ali the foregoing calculations for the How oi water are
made Dy the IOIlONluS NtiI-huONH lVtnH'1'
- x50=v. In which the diameter in feet rs repre-
sented by d. the head by b. the length by and the ye
lOcity In feet per second by W e.
Washington Dec. 6. 1873,