The morning news. [volume] (Savannah, Ga.) 1887-1900, 1897-08-22
THE TALL MONUMENT WAGS.
IT'S LOFTY CAPSTONE CIRCLING
AROUND IN SPACE.


The Movement Recorded Three
Times Day - Due to Wind and
storms and 10 Expansion and Con-
traction.
From the Washington Times.
1t Is not generally known that the
Washington monument which, TO most
people, is symbolicaI of stability and i'm
mutabiIity, shifts out of the perpendicular
nearly every day In fact, this gigantic
pile of stone. that has for 80 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 tb3 monument has been
completed, scientific readings have been
taken three times a day to determine how
much out of the perpendicular the monu-
ment has detected From these readings
it is apparent that now, and for many
years past, the Washington monument
has had its capstone circling around in
space anywhere from one to four inches
from where il ought to be-
Let no one imagine from this fact of the
monument getting a move on itself that
there is any danger of the big shaft top
ping over. 1t is on too firm a founda-
ton for that. The early constructors of
the monument. when it was commenced
back in the forties, did not build upon
the shifting sands. Although the site Sc
lected was al that time marshy and on
the banks of the placid Potomac, and
might have appeared insecure, they profit
NV ha Hret
laid a firm foundation SO firm. indeed,
is this that It can be stated almost with
certainty that the variation of the monu-
ment is not due in any manner TO an inn
perfect foundation. Scientists do not al
ways agree as to the real reason of the
monuments variation, but II Is generally
conceded by many of them that It Is due
to the winds and to the contraction and
expansion of the stone due to the heat
of the sun.
That there are many prevalent theories
a. to the cause of the variation, a reporter
who set out last week to observe the phe-
nomena soon discovered. In the course
of one afternoon various theories were adj
vanced that it was due TO the heat eXpan-
sion caused by the sun, to the winds, TO
the movement of the earth, TO impercepu-
BILE earthquake shocks, to magnetism, and
to an erroneous indicator which failed TO
register correctly. Several persons even
declared that in spite OF science they did
not believe the monument moved at all.
1t is much easier to prove that the mon
ument does move than to lind out why it
moves, There is an apparatus in the
monument now which was paced there by
Gen. Casey, unde whose direction the mon
ument was completed while he was at the
head of the engineer corps of the army.
This consists of a very delicate pendulum,
the slightest vibration of which is record
Cd nv tUo tal with baf
pendiculars in them. This pendulum is
suspended in a protecting cylinder of sheet
IRON which excludes all external forces
which might affect the stability of the
pendulum. The pendulum proper is "A
heavy brass weight, weighing perhaps
twenty pounds, and it is suspended by a
brass wire which is attached to a level iron
girder exactly ia feet above the .eveI OF
the floor of the monument. This point, ia
feet up, is at the center of gravity of the
marble shaft. That is, if it were possible
TO suspend such a gigantic mass of mar
Bile from one single point, where the weight
would be equally distributed that point
would be found where the wire of The pen
dulum commences
It IS easier TO understand when 1t is ex-
planned that Of the 81, 10 tons which are
incorporated in the monument exactly one
half of the weight Is above this point and
the other half below. If this center 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 so that the center Of the monument
at this la foot level were three feet out OF
plumb and yet remain stable, but la order
for the monument to fall the center OF
gravity would have to move something
over fifteen feet. As matter of fact, the
center of gravity rarely moves over an
a..
the monuments ever falling is compare
lively insignificant
However Gen. Casey thought that il
would be wise 10 detect the first Indication
OF variation as soon as it happened, and
he therefore introduced the pendulum. Al
though protected from wind and other in
huences by this cylinder the brass weight
is supended In a small bucket OF water in
order that 1t might be free from unneces-
sary sWaying and still free to Indicate a
movement. On "A support above the level
Of the water are placed two telescopes at
right angles to each other. Both have the
hair line perpendiculars, found In an sur
veyor's telescopes, and both are adjusted
80 that the pendulum wire will drop ac-
curatc!y between these perpeudiculars
The telescopes can be moved so as 20 get
in line with the pendulum whenever II
moves. Indicators on the telescopes show
how much out Of plumb the pendulum is
Oub u AutHf lnuiCdtpIa 0tieci8 the north
and south movement and the other the
east and west vibration.
As the center OF gravity Is but ia feet
above the level, or a trihe over one-third
Of the entire hight Il follows that the top
stone Of the monument moves over three
times the distance covered by the center
Of gravity. TO be exact whatever dis
lance the center OF gravity II out of the
perpendicular should be multiplied by
3.iS9, the number of times ia will multiply
into $50. the entire hight. The reason Is
apparent TO all who care 20 work out the
problem. Thus, n the pendulum shows
that the center OF gravity is out Of the or
binary Just one inch, the top stone must be
3.lS9 inches out Of where II ought 60 be-
The monument officials only trouble them
selves TO take the readings Of the center
OF gravity, because that is the only impor-
tant reading 10 be taken, and the position
o. the rest can easily be computed from
this fact.
Mr. John Hawkins. the custodian Of the
monument who has been IN direct charge
Of the big stone pile since n was completed
over eight years ago, chatted very enter
tainlngly on the subject Of the varying
alterations OF his charge. Mr.. Hawkins