Evening star. [volume] (Washington, D.C.) 1854-1972, 1897-10-02

of about 1J0, OO0,0 600 gallons, and Is perfectly
age of the surrounding country. The dis
tributing reservoir has a storage capacity
OF about 150S50.000 gallons, and is divided
by puddled and paved wall Through
containing 97.600,00O and 53.25O.e00 gallons.
respectively. The Georgetown high service
reservoir has capacity of about 100000
gallons.
I'm addition to the three reservoirs al
ready mentioned, which form a part of the
aqueduct system, there Is another reservoir,
built and controlled by the Commissioners
Fort Reno reservoir. with capacity Of
about 4.50l000 gallons, the reference Of its
water surface when the reservoir L. full
heing about 40 feet above mean tide at
the navy yard.
supply From Reservoirs.
THE Dalecarlia and distributing reser voirs
supply the pumping station and that part
of the District which lies below 100 feet
above datum. The areas lying between the
levels of 100 and 210 feet above datum are
supplied by pumping from the street sta
ton directly into the distributing mains,
the Georgetown high service reservoir be-
ing held as reserve supply. The areas
having greater elevation tran 21O feet
above datum are supplied from the Fort
Keno reservoir. 1t will he observed, there
fore, that the total present storage ca
pacity OF all reservoirs is little less than
or about six days supply.
IN July, 1897, for the first time In its
ms tory, the conduit was permitted to dis
rent meter observations was found to be
7GaNO00 gallons per twenty-fou hours
To-day the average daily consumption is
ABOUT 4o.00e,oO0 gallons, about 90 per cent
OF the ultimate capacity of the conduit
Ten years ago 1t was but 35 per cent, or
less than 27.0O0.00O gallons
10 avoid misrepresentation it should be
stated that while the conduit can supply
the distributing reservoir with T6, 500 600
gallons per day, yet the pipes leading from
the reservoir to the city are already over
taxed in supplying the present rate of con-
sumption, and no relief will be felt by con-
sumers until some method Is provided for
bringing an increased quantity of water
from the distributing reservoir into the
city.
Cabin John Bridge.
General Meigs first proposed to cross
Cabin John bridge valley by bridge 4S2
feet long and twenty feet wide, supported
upon six semi-circular arches of sixty feet
span, resting upon piers seven feet thick
at the top and Of various heights, the high
est being fifty-two and half feet The
estimated cost of this bridge was 2.499
Ihis plan was afterward entirely changed
and the present magnificent structure, the
Rrandest stone arch in existence was erect
ed.
ue toldl length OF the DrAQEe, including
abutments. is $50 feet: its width is 20 feet
inches and It's height above the bottom
OF the creek 100 feet. The span of the arch
Is 20 feet and the rise 57.26 feet. 1t was
commenced In 1857 and completed. with the
exception of the parapet walls in 1854
Ihese walls were built in 1872 10, vehicles
having been prevented from getting Oft
the bridge prior to that time by timber
guards. The entire bridge contains 1928
cubic yards of stone masonry concrete and
prlck work, and cost complete about $751;
OOO The cut stone arch is of Quincy,
Mass, granite. the abutments of Mont
gomery county gneiss, and the rubble arch,
spandrlls and parapet Of Seneca sandstone.
Pennsylvania Avenue Bridge.
1.-The bridge over Rock creek on Penn
| originality as is Cabin John bridge for its
grand proportions.
This bridge is unique among the aque-
duct bridges of the world, in that the two
48-inch mains. through which now flows
about one-half of the water used by the
city. themselves form the arched ribs which
support the roadway overhead. The span
Of this bridge is 200 feet, and it's rise 20
feet. At the time it was built it was the
only one of it's kind in the world, and en-
joys 1t is believed this distinction to the
present day. 1t was much commented up
on by European engineers, and was illus
| trated in many of the foreign scientific
and engineering journals of the time. The
Annales des Points ct Chaussees of Paris,
then the leading technical journal Of the
world. described it as the most novel bridge
building enterprise of the day. In the west
abutment of this bridge still remains the
immense hydraulic ram or water engine
used in supplying the high-service reservoir
In Georgetown until 1876
Pollutions of Potomac Water.
The reading Of Capt. Gaillards paper was
followed by one prepared by Mr.. Arthur p.
To0 ,f t1,o yryt
vey. II was listened to with close atten-
ton. Mr.. Davis, after stating that the ma
| rine hospital has been in the habit of max
ing examinations of Potomac water at
Great Falls for the purpose of detecting
the presence or absence of bacteria, went
On to say that so far as the investiga ton of
individual sources of pollution has pro-
crossed. the indications are that the great
er part of the Objectionable matter which
reaches the Potomac does SO at and above
the city of Cumberland, Nd. On the head
quarters of the North branch are a large
| number of saw mills. Eighteen Of these
mills have thus far been enumerated which
discharge their sawdust directly into the
Potomac or some tributary thereof. Sew
erai tanneries are also in operation in this
region, which discharge foul effluents into
the river, and one of them makes a prac-
tice OF piiing its tan bark after use where
Numerous mines in this region also con-
tribute their quota Of coal dust and of
waters charged with iron sulphates ana
other minerals.
Spots of Pollution,
AT Luke, Md, a small village about
thirty miles above Cumberland, is located
large paper mill. which employs in its
operation thirty-tnree steam boilers. az
gregating In capacity over $500 horse
power. This mill has capacity of more
than one hundred tons per day of a nigh
grade of book paper. and consumes an
enormous quantity of spruce and pop,ar
wood. This wood IL disintegrated bv chem
lcais and heat, all parts being dissolved
excepting the pure celIulose which aftar
cieansing and bleaching. is used in the.
manufacture of paper. All the fntercelluIar
constituents OF the wood, as well "a the
chemicals used In their solution. are dc.
charged directly into the Potomac river
sample Of the ef1uent taken from the "a.
gester OF this mill shows an acid react,o,,
lie matter. Wall oisan-
AT the town OF Westernport f,eo-ga,s
creek empties into the Potomac This
creek receives the sewage OF the town. oS
Westernport. Homecoming, Frostburr and
several villages. It also receives the drain
age from about twenty coal mines wifi
an annual output Of about 5000. 00o tons
OF coal As the creek IL small II nav vol
i a