Evening star. [volume] (Washington, D.C.) 1854-1972, 1885-02-21

tied squarely or evenly all around so as not to
displace the axis or disturb the equilibrium of
the structure. Each of these pairs of tunnels
was filled with cement before the next pair was
excayated, and thus the work was continued
un It'll all the earth within the dimensions given
mad been tunneled out and replaced with con-
crete. To lock the old foundation in with the
formly over the new mass, three large buttressss
on each side of the structure-twelve in all
were carried from the upper surface of the new
foundation up to and under the outer portions
of the shaft; while to sustain the central por-
ton of the old foundation leg of concrete was
projected under the middle Of it, the well in the
center being used as means of access to the
portion to be excavated and filled.
ALL DOUBTS REMOVED.
When the work was nearly completed in
April, 1850, committee of the National Mon
ument Association in memorial to Congress
upon the subject enclosing a succinct state
ment by Col. Casey of the condition of the
work, said:
THAT statement warrants the assertion that
all reasonable or unreasonable doubts as to the
security of the foundation have now been re-
moved; and there is abundant testimony from
the highest scientific sources that by a most in
genious and skillful process, which has been
carried on by authority of Congress, the base of
the monument has been rendered capable of
sustaining as great q weight as it has ever been
proposed to place upon it, and that the shaft,
when carried up to its contemplated height,
will be able TO Withstand the force of a wind of
double the velocity of any which could reason
ably be the subject of calculation or conject-
ure.' On the 29th of May following the en-
iarged foundation was pronounced to be I'm
ished. The entire work had been ACCOMPLISHED
without causing the slightest crack or the least
opening in any joint of the structure. The
joint commission in a communication to Con-
Capt. Davis, his assistant, and said: 1.-THE man.
ner in which the work has been conducted
gives evidence of their high scientific knowl-
edge and faithful performance of duty"
THE SETTLEMENT OF THE SHAFT.
During the progress of the work of introduc-
ing the new foundation the several corners of
the shaft settled as follows: Southwest, 2
inches; southeast, 2.34 inches; northeast, 2.23
inches; northwest, 1 90 inches. The total set
Element of each corner since the work was re-
sumed to the present date is for the southwest,
4O2 inches; southeast. 4-R6 inches; northeast,
426 inches, and northwest, 3.SS inches. The
CURED during the Introduction of the founda-
ton. When Col. Casey made his first
measurements before beginning work it was
found that the shaft was slightly "out of
plumb" Its axis leaned IS, inches to the
northward. The difference noted in the settle
ment of the four corners aided materially in
correcting this slight deviation of the shaft
from the perpendicular The top of the uncom-
pleted shaft, when the work of laying stone
was begun, was found to be not exactly square,
there being difference of nearly two inches
between the length of the south side and that
OF the north side. After the work was COM
menced this difference was gradually corrected
from course to course until within the first
fifty feet of new work it had entirely disap-
peared This makes slight departure from
straight lines in the form of the shaft, which, 1t
is claimed, can be detected by the eye when the
atmosphere is very clear.
THE MONUMENT AND THE LAKE.
In his recent report to the monument COM
mission, Col. Casey says: at has been observed
during the construction of this work that when
any motion took place in the structure due to
addition of weight, the two north corners of the
monument were the first to settle. This is be-
lieved to be due TO the falling away of the earth
on the north side of the structure, thus reducing
the conjugate pressures on that side, and to the
proximity OF the pond just north of the terrace,
in the south margin of which are numerous
springs. AS the bottom of the foundation of
the monument is only some two feet above
mean high water in the Potomac, and the bed
upon which the foundation rests is below the
level of water in the ground at the site, there
may be some connection between these waters
and those of the pond and springs referred to.
In the interest OF increased stability of the mon
ument, and for the better arrangement of the
terrace slopes and grades, it is recommended
that the pond just north of the obelisk be filed
to the level Oft banks, requiring for the pur-
pose about $4,000 cubic yards of EARTH