Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-08-04

pride of the worlds feats in engineering,
says that each block of granite in the new
building is locked together in a way which
Will not admit of dangerous results by sep
aration from contraction or the strain of
expansion.
Prof. Merrill of the Smithsonian the
geolcgist who has written several of the
world s standard text books on building
stones, remarked that the more he studied
marble the more he wondered why men
preferred 1t for structures intended to last
FOREVER The ancients, although more or
less skilled in the philosophical technicali-
ties or architecture, were unable to build
a stone structure which lasted, and their
material was of the most enduring quality.
The expansion of stone by heat is the cause
OF all these ruins, and we may expect in a
thousand years our public buildings, the
Capitol. and the monument as well, crum-
bling to the ground. In fact, according to
Prof. Merrill, our climate is much more
destructive to stone architecture than the
dry climate Of Egypt and the tropical
orient. He says that heat, although the
fundamental cause of the evil, is not the
only element of destruction. The cold rends
the stones which the heat cracks open.
During the constant expansion and con-
traction of stone In summer the outer
crust, being Of higher temperature than
the under layers, becomes gradually loosen
ed. just as will the bark of a tree if it be
constantly pressed back and forth. Small
scales are thus loosened from the exterior
and thus a reduction in volume in grad
ualy going on.
The Eject of Cold.
This is illustrated after a heavy rain
washes the monument, when the pavement
becomes coated with a layer of white mar
BILE particles. This loosening Of the outer
layers OF marble causes assures to open all
through its surface particularly around the
cement between the stones. When the win
ter rain saturates these openings and
freezes within them they burst and the
massive stone is broken just as easily as
is lead pipe or a glass bottle by the freez-
ing of water. Thus the surface each sum-
mer is filled more abundantly with openings
and the freezing of the following winter
ultimately results In ruin. This, however.
did not accomplish the ruins of Egypt and
other hot countries, where snow and ice is
never seen. The heat there worked alone.
Cleopatras Needle in Central Park. New
York, is the best example of the effects Of
our climate upon stone, as compared with
that of the orient. This lay for centuries
on the desert sand, exposed to the burning
heat of the tropical sun. When brought to
this country 1t was apparently sound, but
having been here but a few years 1t began,
as II was supposed, to rot. Some thought 1t
was the chemical action of the salt water
to which 1t was subjected on its journey
over the Atlantic. But the change OF at
mOsphere was the entire cause of the mis-
chief. The theory of Prof. Merrill in de-
tail, is that when the obelisk arrived it was
filled with small assures, caused by the
everlasting heat of Egypt. The mass of
stone was like huge sponge. only the
holes were not perceptible to the naked eye.
one winter was sufficient to make great
Roadway in the destruction. 1t absorbed
tremendous amount of water, which eX-
panded upon freezing. and erumbied the
obelisk to a greater degree of destruction
than any other stone ever experienced here
In the same length of time.
Marble is destroyed by heat much more
readily than granite. its coefficient of ex-
pansion being much greater, while de-
structive chemical effect is presented by
the combination of its elements and the
carbontc gas in the atmosphere. Ancient
present excellent examples of
the effects of sunlight upon stone. The
face of a tombstone upon which tire sun
constantly shines in the daytime is usually
crumbled and decayed. while the shady
side is invariably sound. The south and
west sides of the Smithsonian building
show a scaling of the stone The other sides
of the building. which are protected by the
National Museum and the tall trees of the
park, are uniniured. Church 3teepes of
stone usually show a crumbling the
south or east sides, while dwellings,. stu
ated where the sun has unhindered at
tack. crumble more readily than those
which are sheltered by adjacent buildings
store for the man who will invent remedy
for the scaling evil caused by the sun.
The only remedy seems to be an array of
canvas screens or mammoth parasol to
keep off the gaze of old Sol. Numerous
paints have been invented, but builders all
say they are of no avail. The old Capitol
and the White House are both crumblng,
regardless of the gallons of white paint
daubed on them continually.
The Marble Terraces.
It was a lucky day when Congress de-
cided to build the new dome Of iron. Had
1t been built of marble or granite 1t prob
ably would have lasted scarcely century.
The reason iron was selected was because
1t was cheaper and because 1t was not
thought that the sandstone foundation could
support such a mass of stone. There was
no thought concerning the comparative en-
during qualities of metal and stone under
the burning sun. The effects Of the wealth
er are already becoming noticeable in the
new terrace of the Capitol. The huge
solid marble pier. which stands in the
northwest corner OF the wide boulevard, has
been moved more than an inch from each
of the adjoining marble ratings, which
have already expanded In the heat leaving
1t out of place when they contracted. The
collection of ice In this crevice will cause
still greater damage, and the heavy rier
Will soon have to be moved to it's former
position. only to be driven out again. This
same trouble occurred while the monument
remained diminished Tor several years. The
spaces between the stones on top We're
exposed to the rain, which became frozen
In winter, tearing them all apart. They
were driven several inches over the edge
and several layers of stona had to be re-
moved from the top before the work was
continued.
There is no building in the world which
offers SO much attraction to lightning as
the Capitol. 1t is struck many times when
the loud report of the thunder Is the only
evidence of stroke. The building how
ever, is not furnished with lightning Iod.
This provision would be entirely unneces-
sary, since the great dome is a sufficient
conductor to carry away all the lightning
which strikes in the country. The system
of distributing currents, however, seems
odd, there being nothing but the tin roofs
over the wings to carry 1t away from the
dome. This system has always proven
successful and every time an electrical
storm has gathered about the building the
zigzag fluid has been equally distributed
among all jewellers within without partial
ity. Architect Clark thinks there is no
safer system than this simple one and 1t
Is generally conceded that the difference
of potential between the opposite wings of
the great building is generally more pro-
ductive of dangerous explosions during the
hot days of the Wilson bill than the cleo
trio fire.
Tho monument, situated as 1t Is in the
very barest section of the city, Is more In
danger CT an assault from above than any
other eiifica 10 bo