Evening star., 1895-06-13
IMPROVING THE POTOMAC
Major Davis Report Of the Operations Dur
ing the Month Of May.
Dredging the Channel and Work
still to BE DOnc-Repairs to the
Aqueduct Bridge.

Major Davis has made a report to the
chief of engineers Of operations for the
Improvement of the Potomac river during
the month of May. He says that dredging
In the Washington channel under the con-
tract with the New York Dredging Com
pany was completed May %. The amount
Of material dredged and deposited on the
flats during the month was G4,472 cubic
yards. The channel was widened to 400
feet from the upper end of the arsenal
grounds to G;esboro' Point, a distance of
about 1900 feet, the depth made being 20
feet at low tide. The total dredging in the.
Washington channel was 221,742 cubic
yards, and In the Virginia channel 202, 4SS
cubic yards. making a total of 424,225
cubic yards.
Work Still to he Done.
The construction of the sea wall in the
tidal reservoir was continued, and $50 lin
ear feet completed during the month
Favorable progress was also made with the
work on the training dixie on the west side
of the Virginia channel. The channel from
the upper end of the arsenal grounds to its
junction with the Virginia channel is still
to be widened to 400 feet and made 70 feet
deep. The widening and deepening of the
Virginia channel below the Long bridge,
so as to facilitate the discharge of freshets
and prevent overflow of the city,i also still
incomplete. The reservoir outlet is COM
plete, except the railing. All the dredged
material MAJ IS being being deposited on the flats,
ana practically the entire area to be re-
claimed has been raised above the over
flow at ordinary high tide.
Repairs of the Aqueduct Bridge.
In special report in regard to the repair
of the Aqueduct bridge Major Davis gives
a detailed account of the work on the Golfer
dam at pier No. 4, under the contract with
| Smaller & Schniglau. The repairs to the
dam having been completed. pumping was
resumed May 20 and continued cautiously
until May 30 when a level of 22Is feet be-
low tide was reached, exposing the mud
everything the rock bed of the river and
showing the whole of the eroded cavity in
the west end of the pier. This cavity was
round to be about twenty-five feet wide at
the bottom, nineteen feet high and twelve
feet deep. Besides this large cavity the
ss, s,aes o. tne 1ooungs were found to be un-
dermined from three to four feet for much
of their length. The cross shores or braces
in the original cofferdam of 1898 had been
left In place and built into the masonry of
the pier. They have proved a source Of
weakness. SO Major Davis says, as it was
found that the masonry near the cavity
lad cracked seriously along the westerly
line OF shores. The masonry of the old pier
below low tide level was found to be of an
exceedingly poor quality, the stones having
| been apparently laid as they came from the
quarry, with little attention to shaping or
proper beds.
Pumping Out the Dam.
Major Davis says it is, therefore, not sur
prising that the masonry was eroded by the
fresh currents. The grantee ice breaker
has been supported during the pumping out
of the dam by heavy wooden struts. put in
place by the diver. 1t was found that the
difficulty of supporting this overhanging
masonry and the danger and difficulty of
building up under it would be SO great that
1t was deemed advisable to take it down
before commencing the new masonry This
work will be next undertaken. At the
close of the month the dam was still held
at the depth of 221a feet below low tide A
pump was kept in slow operation to pump
out the leakage in the dam, which is esti-
mated at 600 gallons per minute. 1t is pro-
posed to push the work on the pier as
rapidly as conditions will permit.