Evening star. [volume] (Washington, D.C.) 1854-1972, 1860-09-18
GEORGETOWN.
Correspondence Of TAs Star.

6EoRsKrowS, September II. Iseo
WotK upon all the unfinished portions Of the
washington Aqueduct 10 now fully resumed nv
the contractors, as noticed in the Star OF saturd,
last. The magnitude and grandeur Of this splendiS
triumph Of engineering skin, and the beauty 81
in details, are becoming more fully developea =.
1t approaches completion. Two Of the pronin.n,
features Of the work, the High Service Res.ryoi,
and the bridge over Rock Greek, being located
here, viii add to the attractions city presents
TO residents and visitors. The High Service
Reservoir Is located on the corner Of Road and
High streets, upon the ground known as Lees
hill Itisa circular reservoir l20 feet in diameter
and VIII contain So, goo gallons Of water. II
will be covered by spherical brick dome of :
feet IN thickness and 50 feet interior height The
foundations are of concrete sunk TO depth Of IL \
feet below the natural surface. The bottom Is
eIcavated In the form OF reversed cone, lowest
In the center, at which point the Influx pipe
enters. The dome will be surmounted by an
ornate, and finely proportioned lantern. large
force Is now at work on the dome, and expect 10
complete the brick masonry in about two months.
The brick work for height Of 81 feet or one foot
ABOVE the water level, Is 20 be lined with boiled
coal tar and dry hydraulic cement this liniI Y
being between the inner and outer courses The
wall 10 the height Of the water line will be SUD-
ported by an exterior sodded embankment sup
ported on the side of Road street by revetment
wall The brick work will be strengthened by
hoop iron built into the courses The influx and
emux pipes enter by brick-lined gallery ex-
cavafed In the hill under the foundation Of the
reservoir. The dome with the lantern surmount-
ing IL, when completed, will be the most promI-
nent feature OF our far-famed Heights The en-
CINE intended to pump water into this reservoir
Is located In the west (Georgetown) allotment Of
the Aqueduct bridge over Rock Creek. This
engine Is beautiful piece of mechanism, NV ORTIZ
ingtonS patent Of 1885, and is capable Of pump
ing 100000 gallons in ten hours The power is
obtained by pipe connecting with the supply
main. The distributing reservoir is AS feet above
tide, and the waste water discharges into Rock
Greek at an elevation Of feet above tide, but the
effective pressure will not be this difference of
4l feet at all times, because the draught from the
mains for supply will diminish the head. The
water to be pumped will be drawn from the same
mains and delivered into the reservoir at height
above tide Of 2l5 feet, through 1O-inch main,
$500 in length.
The iron bridge over Rock creek, to convey the
water across, and support roadway for travel, is
remarkable for the boldness of its design ana its
graceful proportions. That and the stone bridge
at Cabin John, f built anywhere in Europe would
attract universal attention, and descriptions and
drawingssown broadcast would spread their fame
throughout the civilized world Here We are too
busy Presidentmaking to attend to such trivial
mattefs To return: the span of X ock creek bridge
Is 2VO feet. The arch is composed OF two ribs
winch are cast iron pipes Of 40 inches interior di
ameter. These pipes are in lengths of about II
feet are cast straight with bevelled and fanved
ends, and are connected by screw bolts through
the hanges The joints Of these ribs were faced
on SO true that when screwed up they were per-
fectly water tight, with packing of red lead and
oil only. The joints are concealed by neatly de-
signed ornamental coverings Of cast iron. The
ribs are kept at proper distance from each other
by diagonal braces of cast and wrought iron. The
sPandrel filling is Of wrought iron, H beams, and
nat bars riveted The meeting points Of the braces
are covered with handsome 'rOsettes' OF cast iron
eighteen on each side. The floor Of the bridge is
Of wood, and the pipes Of the arch ribs are lined
with three-inch slaves Of plank. Messrs Denmead
sons, OF Baltimore, are the contractors for the
wood and iron work, and their intelligent fore
man, Mr. Nc Mahon, has employed here a force,
which WILL In short time, complete their por-
ton Of the work, which, for neatness Of finish,
does credit to all concerned. Proposals for paint
ing the wood and iron work are being received
by them to-day. The massive abutments Of the
bridge are finely designed, and were raised high
enough last season to resist the thrust of the arch
There has been some delay in commencing opera
tions on them this season in consequence, we be-
lieve, Of want of facing stone which is obtained
from the grey stone quarrits at Seneca. We sup
pose the delay will not continue much longer, as
we understand that our young friend and towns
man, Mr.. James McHenrv, Is continued in his
former position on the work inspector of masonry
and assistant engineer we believe,) by Captain
Benbam, and that he will enter upon his duties
this week. We may shortly state for the informa-
ton Of your readers the present condition Of the
work all along the line, but make no promises 10
that effect.