Evening star. [volume] (Washington, D.C.) 1854-1972, 1895-03-06
Preparations to Be Made for Rais~
ing It.
STONE FROM THEGOVERNMENT QUARRY
Immediate Advantages to Be Had
From This Seasons Work.
WORK WILL BEGIN AT ONCE

Work on the Great Falls dam. which
Congress provided should be raised two
and a half feet, will begin before March In
much older. The appropriation of $125.000
is Immediately available and as rapidly
as possible plans are being made. under
Colonel Elliot's charge. for beginning the
improvement. Necessarily there will be no
work on the dam proper until the period
of low water. which is not likely to be
much earlier than July. Yet there is q
great deal Of work in preparation, which
will begin at once. Although Colonel FL
liot retires from the active list of the army
on the 31st of this month, and will accord
ingly be relieved from charge of the aque-
duct, he will carry forward the prepara-
tions for raising the dam and turn the
enterprise over to his successor as a work
in progress.
Preparations Necessary.
The details of the work are in great part
determined by circumstances already fa-
vorably existing. The character of the
stone to be used was settled from the start
The dam was made of Seneca sand stone
from the government quarry, about eight
miles from Great Falls up the Potomac on
the Maryland side, convenient to the
Chesapeake and Ohio canal This quarry
yielded the vast amount of stone require
for the original work on the dam. From
there also came the splendid large coping
stones that cover the work. There will
be required for raising the dam two and
a half feet 2,225 cubic yards of stone
which will take several months to quarry
and ship to the falls. The convenience Of
the quarry to the canal makes the cost
of transportation comparatively light
These stones will all need to be faced, SO
as to bed firmly in cement, and the work
of cutting them thus will also consume
considerable time. Before the dam is dis
turbed at all the stone requisite for the
new work will all be Quarried and laid
down at the falls and hewn into usable
which might temporarily reduce the water
supply and run out of the stone needed.
So the first thing will be e. provide all
the materials necessary.
Where Work VIII Begin.
The first part of the dam to be changed
will be that on the Virginia side of the
river. Work could begin at both sides and
progress until the two forces Of workmen
should meet in the center of the dam. But
in all probability but one force will be put
at work. and that on the end Of the dam
furthest from the base of supplies. AS the
dam is but eight feet wide, the force of
men to be employed at any one time must
necessarily be small. Cement, stone and
tools must be carried along the dam to the
point where work Is going on. So but lit
tie of the dam will be torn up at time
about one hundred feet. The coping stones
will be lifted with a derrick stored on top
of the dam the new masonry laid in until
the necessary. two and a half feet of rise
is secured, and the coping stones put back
in place. These surface stones will be Sc
curely bolted into the dam with two-inch
bolts, five or six feet long. Each bolt is
split for six or eight inches ct the end
which enters the mason work, and is driv-
en- down upon an iron wedge, which sepa-
rates the two half ends of the bolt and Sc
curely holds it. Sulphur is then poured in
around the bolt to make it the more secure
in place.
Immediate Good to Result.
There will be some appreciable advan-
tage to result from beginning the work on
the Virginia side of the dam. The main
body of the channel is on that side Of the
river bed. Two-thirds Of the water Of the
Potomac flows there, and as soon as the
dam is raised there the back water be-
tween Conns Island and the Virginia shore
will measurably increase up around the
head of the island and send a greater flow
into the aQueduct.