Evening star., 1901-11-09
ALI High Structures and Mountains
Affected by Suns Action,
LIBERTY STATUE mods 10 SHIPS
Washington Monuments Top Cir
cles Six Inches Day.
EVEN SAND PILES WALK

Copyright. I9O1.)
Written for The Evening Star by Theodore Waters
1t may sound fanciful vet il is literally
true that the great arm of the statue of
liberty in New York harbor beckons a well
come to the steamers that come up the
bay every day. The tall office buildings
bend their heads and the big Brooklyn
bridge lifts itself up and lets itself down
every day, for all tall towers move and
great structures sway just as surely as the
earth turns once in twenty-four hours
The cause is not far to seek, for it is the
action of the sun itself.
One thing which would have. made the
Tower of Babel impossible is the tendency
of all tall structures, whether built of
metal or stone, to move around in mid-air
under the action of heat or cold. 1t IS
pointed out that the "tallest skyscraper'-
the mile-high office building-would, after
it had been erected certain distance into
the air, turn over like the lash of a car
riage whip, due partly to the impossibility
of making it rigid enough. But. aside IRON
this even were the architect able to con-
Struct an iron shaft or the quarryman able
to erect a stone shaft in one solid piece 4
mile high, the top of that shaft would nod
its head slightly at the sun just as surely
as the more flexible sunfiower does now
each day. For all tall. structures move, sky
scrapers, church steeples, monuments and
tall towers bend over or follow the
around in a cirble each day. All bridges
slide forward and back on hot and cold
days. The Brooklyn bridge has, in
deed, a buckling plate in its center,
which is intended to take up the slid
ing motion that constantly goes on in
the structure. This movement of bridges
is somewhat on the principle of the creep
Ing of railway tracks, which contract in
cold and expand in hot weather. some
times to the extent of four hundred and
twenty millimeters to the rail. There is
on the banks of the Missouri river vast
quantities of sand which are constantly in
motion. OF course, glaciers move, and there
is a mountain in France which has moved
its position perceptibly in century. st.
Paul's Cathedral, in London, not only has
a tower that moves back and forth but the
building itself is thought to be sliding slow
| ly into the Thames
The Plumb BOb's story.
The Washington monument, on the bank
| of the Potomac, is so noted for nodding
| it's head at the that the engineers have
erected apparatus in the structure to show
! just how much it may go out of plumb.
| The monument, of course, is hollow, and
| IA feet up the inside in one of the corners
| extends wire, hung from a beam. On the
| end of this wire hangs a 2J-pounG plum
| bob made of brass. 1t just clears the floor.
| On a platform near by is affixed a spyglass,
| the objective of which has a vertical line
scratched upon 1t. The glass is affixed to
graduated scale and may be moved for
| ward and back by means of a thumb screw.
| Under normal conditions the spyglass is
adjusted so that If you look through it the
| long wire with the plumb-bob on the end
| will be directly opposite the vertical line
| scratched on the objective. On hot days
| the top of the monument leans over, and
| of course, the plumb-bob swings over with
| it like a pendulum. By adjusting the glass
until the two lines are directly opposite
again the graduated scale Immediately
| shows how great a movement has taken
| place. 1t Is calculated that this leaning
| has been at times as great four inches.
| The dome of the Capitol building in Wash
! ington has an ellfptical movement, and an
! experiment was tried TO show its scope. A
| wire was hung from the middle of the
dome inside the building, extending down to
| the floor of the rotunda, and on the lower
| end of the wire was hung plumb-bob SIM
| liar to the one in the Washington monu-
| ment. But in the lower point of the weight
was inserted a lead pencil The point of
the pencil just touched the floor. A large
| sheet of paper spread upon the floor
| Every day as the dome moved it dragged
| the pencil over the paper The mark made
was in the form Of an ellipse six inches
| long. The dome would start moving in
| the morning as soon as the rays of the sun
! began to act upon 1t, and slowly as the day
| advanced, the pencil would be dragged in a
| curve across the paper until sundown, when
reaction would take place, and the pencil
would move back again to its starting
| point. But 1t would not go back its
own penciled track, for the cool air of night
| would cause the dome to contract as much
| on the one side the sun had made it eX-
| pand on the other. and so the pencil would
| form the other half of the ellpse, getting
| back to the starting point already to start
| out again by sunrise. One of the guides in
| the building says he was able within cer-
| tain limits to tell the time of day by the
| position of the pencil on the paper, and it
| Is easy to imagine a clock, the face of
| which would be the ellipse with the figures
| drawn in their places and the hand OF
| which would be the plumb-bob hanging on
the wire and pointing to the time of day.
Excites Fear Sometimes.
! The Philadelphia city hall, which is high
er than the Washington Monument, leans
trifle every day, and the Eiffel Tower, in
| Paris, insisted on moving in curves and
| leaning so much that it once got upon the