The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1898-02-05
The Tall Monument Ways.
From the Washington Times.

people. Is SymD0llcal OF Stability anu I'LL
mutabilitv, shifts out of the perpendicular
nearly every day. In fact, this gigantic
pile of stone. that has for so many years
been the most conspicuous landmark OF the
capital on entering the city, rarely occupies
the same position twice on two consecutive
DAYS. For eight years. in fact, ever since
the monument has been completed, sclen-
tiic readings have been taken three times
a day to determine how much out OF the
perpendicular the monument has DETECTED.
From these readings it is apparent that
now, and for many years past, the Wash
ington Monument has had its capstone cir
cling around in space anywhere from one
to four inches from where it ought to be.
Let no one imagine from this fact OF the
monument getting move on itself that
there is any danger of the big shaft top
ping over. 1t is OH too firm a foundation
for that. The early constructors of the
monument. when it was commenced back
in the forties, did not build upon the SHIFT
ing sands. Although the site selected was
at that time marshy and on the banks of
| the placid Potomac. and might have ap-
peared insecure, they profted by a lesson
from the Bible. and first laid a firm foun-
! dation. So firm. indeed is this that 1t
can be stated almost with certainty that
the variation of the monument is not due
in any manner to an imperfect foundation.
Scientists do not always agree as to the real
reason of the monument 5 variation, but 1t
is generally conceded by many of them that
it is due to the winds and to contraction
and expansion of the stone due to the heat
of the sun
1t is much easier to prove that the mon
ument does move than to find out why 1t
moves. There is an apparatus in the mon
ument now. which was placed there by
Gen. Casey, under whose direction the
monument was completed. while he was at
the head of the engineer corps of the army.
This consists of very delicate pendulum,
the slightest vibration of which is recorded
by two telescopes with hair-line perpendic-
ulars in them This pendulum is sus
pended in a protecting cylinder of sheet
! iron. which excludes all external forces
which might affect the stability of the pen
dulum. The pendulum proper is heavy
brass weight, weighing perhaps twenty
pounds, and it is suspended by Il brass wire
which is attached to level iron girder ex-
actlv IA feet above the level of the floor of
the monument This point, Ia feet up, is
at the centre of gravity Of the marble shaft.
! That is. if it were possible to suspend such
Il gigantic mass of marble from one single
point. where the wei chit would be equally
distributed. that point would be found
where the wire of the pendulum com
menceS.
1t is easier to understand when it is ex-
| planned that of the 81, 720 tons which are
/ incorporated in the monument exactly one
half of the weight is above this point and
the other half below If this centre of
! gravity should ever get outside Of the base
of support-that is, the square foundation
of the monument-the shaft would fall
! over For instance the shaft might lean
over 50 that the centre of the monument
at this III foot level were three feet out
Of plumb and vet remain stable, but in
order for the monument to fall the centre
of gravity would have to move something
over fifteen feet. AS "a matter OF fact the
centre of gravity rarely moves over an inch
and fraction. so that the danger Of the
monument ever falling is comparatively
insignificant.
Mr. John Hawkins the custodian of
the monument, who has been in direct
charge of the big stone pile since it was
completed over eight years ago. chatted
very entertaininely on the subject of the
varying alterations Of his charge. Mr.
Hawkins has taken the readings Of the in
dicatnrS each day for something over eight
years and probably knows much more
about the variations than any one else con-
nected with the monument.
The variation does not get more than
three or four inches out Of the plumb line,
he said though that is an extreme. The
variation is very irregular at all times, and
have not entirely made up my mind vet
as to Just what causes it. have seen it
stated in various publications that it is due
to the expansion and contraction caused by
the heat of the sun. The people who lay
it to this cause, however, assert that it
moves toward the north, because the sun
is hottest in the south. My experience of
eight pears has been that the monument
moves toward the southwest. Each month
we use the daily observations to plan out a
chart of the movement, and it is almost in
variably toward the southwest | guess
there is not much doubt that the sun does
have some influence on it. but | should
think that the north side, being coolest,
would contract and draw the monument
that way. Instead, however. it goes to-
ward the southwest. | am sometimes of
the opinion that it is not due to the sun
that the monument moves, because, on the
hottest days, we can still read the indica-
tons that point toward the southwest.
1T has also been stated that the varia-
ton is due to winds My experience has
been that on days when the wind was
blowing sixty miles an hour-so hard, in
fact, that you could not stand up by your
self out there on the hill-at the very time
when you would expect the indicator to
show great variation in the direction in
which the wind was blowing there would
still not be the least bending in that direc-
ton. have noticed that time and again.
At other times, in dead calm, have
been surprised on looking at the indicator,
to find the pendulum swaying and bobbing
around as though the monument was shak-
ing in an earthquake. At such times it
would indicate big variation. This can
not be due to air currents within the mon
ument, because the pendulum is protected
by cylinder, and the indicators are pro-
tected in closed closet We have tested
the indicators when the elevator is running
up and down, inside the shaft, but this has
never had the slightest influence on the
readings.
! ST SaamS to mo that tho variation o4