Evening star., 1895-09-14
Progress During August on the
Aqueduct.
TESTING TEE STRENGTHOF THETUNNEL
The Conduit for Once Filled Flush
and Full.
SUNDRY DATA PRESENTED

Maj. Knight in charge of the Washing
ton aqueduct, has made a report tn the
chief Of engineers in regard to the opera
tions during the month of August. In re-
gard to the dam and other works at Great
Falls he says:
"a deposit of sand at the inlet of the con-
duit was removed, and a channel cut
through the rock below the dam, so that
the conduit between the river and the gate
house could be drained when stop planks
above the inlet to the conduit are put down.
The temporary dam above the incomplete
fishways backed the water up into this
new channel, and therefore one panel of
the dam was cut away. 1t may be neces-
sary to remove a second. At the begin
ming of the month the river was OF of
foot above the crest Ut the dam. On the
21st it had fallen to O.5, where it remained
the rest of the month. This height of six
inches on the dam corresponds to the low
water stage. The water in the receiving
and distributing reservoirs rose almost
steadily during the month, in the former
to 1876 feet and in the latter to 145.1O feet
above datum, or in the former to about
nine inches and in the latter to eleven
inches below the full stages. Prior to the
18th ultimo water had been flowing into
the receiving reservoir through the break
in the bye-conduit and through the south
connection. On that date it was admitted.
Various improvements.
Maj. knight reports that the different
mains were flushed on the 31St of August.
The extension Of the Washington and
Georgetown cable road to the union depot
necessitated changes in the castings of the
1-inch air valves on the 30-inch and 36-inch
mains at 34th and NJ streets, and of the 4
inch blow-of on the 30-inch main, and the
6-inch blow-of on the 36-incE main at Po-
ohoy, rT-xara
made by the railroad company. Permission
was given the Washington and Great FAILS
Electric Railway Company to carry an
aerial feeder wire across the conduit road.
Agreements were made with this company
as to the structure for crossing the 12-inch.
::0-inch and 36-inch mains near the FoXhall
road, and as to the manner OF relaylng the
S-inoh drainage pipe from the pipe vault
of the distributing reservoir, Where thls
pipe passes under the roadbed and thence
toward the canal
Raising the Dam.
The operations for increasing the water
supply of Washington by raising the height
of the dam at Great Falls are stated as
follows: "QuarryIng and cutting and trans
porting stone were continued. OF about
$500 blocks required 322 were taken from
the quarry to Great Falls. making I66 now
ready TO place. There are 100 more at the
quarry awaiting cutting and transporta-
ton. The erection of cement shed and
derrick and the laying of railroad track
from the canal to the Maryland shore were
commenced. A sixty-foot barge for carry
ing stone from the quarry was built and
the stone crusher was repaired prepara-
tory to its use in crushing stone for the
concrete filling of the dam. A contract for
furnishing, erecting and testing a cable
way for use in raising so much of the dam
as crosses the river channels was prepared
and submitted to the chief of engineers
for his approval.
Damages From Overflow.
On the 9TH of August the Secretary of
War approved the recommendation of the
chief of engineers that an officer of the
corps of engineers be designated to meet
an engineer, to be selected by the Chesa-
peake and Ohio canal authorities, to form
commission to report as to the claim Of
the representatives of the canal company
against the United States for damages
from the proposed raising of the dam at
Great Falls Mr.. G. L. Nicolson, general
manager of the canal, was selected by the
canal authorities to act with Maj. H. NJ.
Adams, corps of engineers, as the conf
mission in this matter The probable oper-
atoms for September include the first work
of raising so much OF the dam as crosses
Conn's Island and erecting the galloway"
Testing the Tunnel.
In regard to the project for testing the
tunnel COHuult, WHICH IHcluQeS ullIiS lHS
tunnel with water, Major Knight says that
at the beginning of the month the conduit
was slowly filling with seepage water, and
at ii am. August the seepage water
had reached 324 feet above datum, when
water was turned in from the distributing
reservoir in moderate amount and con-
tinued flowing until pm. of the 9th uiti-
mo, when it had risen to 54.24 feet above
datum. From this point the conduit was
allowed to fill with seepage water. For
the first time in it's history, the conduit
was completely filled exclusive of upper
ends of shafts) on the 18th of August The
highest level attained by the water was
recorded at pm. August 20. when it
reached an elevation of S4,6G feet above
datum, or HALL feet above the bottom of
Rock creek shaft. At this time the pres
sure on the roof of the tunnel was about
fortysix pounds to the square inch. Dur
ing the month borings were made along
the foot Of the outer slope of the dam of
the Howard University reservoir. These
and other borings will be made during the
present month, and estimates will be made
of the cost of completing the reservoir and
of its connection with the existing conduit.