The Telegraph-courier. [volume] (Kenosha, Wis.) 1888-1946, 1911-04-27

tells in this month s issue just what
happened when the powder mills at
Pleasant Prairie let go, and reasons
why plate glass in Kenosha and all
over the county was shattered.
1t was pressure, as of blow, from
the inside of stores and residences, that
caused the glass to break and the dam
age to be done here.
Largest Previous Explosion.
The largest amount of explosives ev-
er Intentionally discharged at one time
seems to have been 100 tons of blast
ing powder, backed by twenty tons Of
dynamite, used in the destruction of
the Great Hell Gate reef, which until
1876, made East River, New York, q
terror to shipping. But that was a
mere baby's frecracker when compar-
ed with the more than thousand tons
of giant powder and the 35 tons of dy-
Mantle which-exploded by some mys
FERROUS and forever hidden accident
dug holes in the earth hundred feet
deep, by three hundred feet square and
threw half the population of the mid
die West into spasm of fear.
Upset Five States.
For q few seconds the equilibration
of five states was disturbed. A whole
village was wiped out of existence;
chimneys were overturned and thous-
ands Of panes of glass were broken
over a section a hundred miles in dia-
meter. In Chicago and a score of
smaller cities the police were called
out and fire companies rushed madly
around the streets searching for I'M
located and nonresident explosions.
The emergency exits in hundred the
aires were blown open by the same sud
den blast and in one or two instances
frightened men attempted to save them
selves by leaping from the windows.
What Caused Shock Here.
The first result of the explosion was
the instant liberation of billions of Gu
bic feet of gas, which swept out from
the common center with almost meal
culable violence. 1t was this first ham
mer blow of the gaseous wave, seeking
room for expansion, which shook build
ings and overturned brick chimneys. 1t
was followed an instant later by the
return of the compressed air about the
circumference of the circle, rushing in
toward the center, where something
like vacuum had been created. This
rebound of the great air wave greatly
lowered the pressure outside the houses
and other buildings, leaving the press
ure inside much higher and more nearly
normal. Tt was this higher pressure
en- the inside that caused the destruc-
ton of window glass, every pane, so
far reported, having fallen out, as if
struck a heavy blow from within The
pressure from without, in the first in
stance. was undoubtedly as strong as
the reaction which followed it. That
it was not as effective in destroying the
glass may have been at least partially
due to the fact that window-pane is
supported against outside pressure by
the whole strength of the heavy win
dow frame, while against pressure from
within, there is no protection but the
putty.
Moved Earth Waves Too.
In addition to the air waves, earth
waves of great intensity and duration
were set up by the explosion. Much
comment was caused by the fact that
while at a distance of more than 300
miles in certain directions the earth
vibrations were strongly felt, in other
directions and at distance of only
fifty miles they passed unnoticed. Ov-
er large portion of the South side of
Chicago, for instance, there was no re-
cognition of the explosion, while in
Cleveland, Ohio, the seismograph vib-
rated violently. The great difference
is due to the varying constitution of
the crust of the earth In directions
where continuous strata of solid rock
ran away from the center of the dis
turbance earth waves were transmit
ted quickly and with slowly diminish
ing violence, while when such strata
gave way to great deposits of sand and
gravel the shock was poorly transmit
ted and quickly absorbed. The fact
that terminal moraine of loosely
packed sand and detritus underlies
much of Chicago accounts for the es-
cape of certain parts of the city from
any very noticeable effects of the earth
waves.
The after effects of the explosion
have been varied. In two or three cas-
es the deaths of people who were ser
iously i'll at the time have been as
cribed to the shock. The Dupont com
pany has come forward and voluntarily
offered to pay all damages caused by