San Antonio daily light. [volume] (San Antonio, Tex.) 1886-1907, 1897-10-15
BUILDINGS MOVE FROM SUN.
Result of Experiments by Architects
and Scientists.

Result of Experiments by Architects
and Scientists.
The problems confronting architects
have increased greatly in recent years
because of the upward tendency of dig
businessbuilding Beauty of form and
convenience of arrangement are now of
less Importance than great strength to
resist the strains which every tall struc-
ture must meet. Every time cyclone
has occurred in the west there has been
speculation as to what would occur if
big windstorm visited the business
district of New York. Architects and
engineers have anticipated this posi-
bility. They have considered also the
effect of the suns heat on great build
ings, because observations have shown
that on a hot day these tall structures
move away from the sun as though
shrinking from its heat; while on a
cold day the marble is rent by the freez-
ing of the winter rain in assures made
by the expansion of the marble in mid
summer.
These effects are not so noticeable in
New York as they are in some other
cities, because New York streets are
narrow and the tall buildings are so
close together that they protect each
other from the sun. In Washington
scientific observations have been made
which prove conclusively the effect of
heat and cold on marble. The Wash
ington monument stands on slight
eminence in the middle of a plain. 1t
is wholly unprotected from the ele-
ments. When the monument was be-
ing erected the investigation of its vi
bration was begun, a cord and plummet
being suspended from the top of the
structure, with needle to make the
record of any movement. One day it
was reported that the monument was
about to fall. The needle had made
number of eccentric variations and was
still moving about when the observation
was taken. Investigation showed that
an owl had got into the shaft and, flap
ping about, had caused the vibration Of
the cord.
The needle under normal conditions,
however, showed a movement of the
shaft, and observations made since its
completion confirm this record. There
is cord hanging from the top of the
monument, protected by metal tube.
At the end of this cord is fastened a
pendulum which hangs in a bowl of
mercury. The pendulum moves with
the movement of the column, but it
cannot oscillate. The record of the
pendulum is taken every day. 1t shows
that the top of the marble column, 555
feet high, moves four inches to the
north on a very hot, clear day. AT
night the monument returns to the per-
pendicular. The extraordinary power
of the suns heat is we'll illustrated by
its effect on the monument. The mar
BILE column weighs 1920 tons.
Scientists say that the monument is
not injured in the least by its little
journey in the world" but this is due
to the fact that it is built of many
pieces of marble. The obelisk in Cen
trail park, which is single block of
stone, deviates more than the Washing
ton monument. The Bunker Hill mon
ument, which is only half as tall as
the Washington monument, moves
about two inches from the perpendicu-
lar. Iron buildings are affected no less
than those of marble. The dome of the
capitol at Washington moves from the
south and west, away from the sum-
mer sum-. Y. Sun.