Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1916-08-27
Science Explains the "Freaks" of Mew York Great
Munitions Explosion Sound Waves and
Echoes That 7rauel 100 Feet Second, Twist
Iron Bars Without Harming the Glass Behind
Them and Strip Mems Clothes from Their Bodies
as They Blow
Them THROUGH
the Air

before in an office near the to- Of a
nearby skyscraper.
NOW. as before said, the big sound
wave travelled outward from its sourca
specifically. Thus. along the street love,
the wave would strike a vertical object
with the greatest force hitting upper
windows in buildings only a slantinr
blow. In perfectly Simple case. not
complicated with echoes, the lower win.
COWS would always suffer more than IN
per windows OF the same character. nro.
vided the explosion happened on leye,
with the street.
Now. sound wave may no, only be
reflected by solid wall or wall with
lew windows or closed windows bu, u
may be absorbed by wall with plenty
OF windows If the latter are omen.
There may also be what is known a.
sound shadow. Suppose the wave struck
a corner obliquely. Part would he 70.
nected by the nearest building. the other
side OF this building being thus in
sound shadow and not being damaged
mucn-al"ays providing that no echo
got to H.
get the iu!l force Of the wave and would
nave windows shattered. Suppose there
we're wide, tall building on this onno
site size Then an echo would be caused
which would break windows on the sound
shadow side further up the street.
inc iron bars holding the iron shut.
'ers on the courthouse in New York,
which were bent outward. show the ef
iect OF rarefaction-the air pressure
10
outward when the pressure on the ont
side Of them was removed Tho ,I,es
In the same windows was not damaged
Tor the air could not get through the
shutters. and so the air enclosed between
inc windows and shutters kept its same
pressure against the glass Just as II did
against the shutters, the only difference
peinG that the glass had an equal pres.
sure on its other side. while the shut.
tiers did not
AS several explosions happened one
after another, some glass was undonht.
edly loosened by one and dspaced nv
ahother or part might be broken out by
one ond part by another
me reason H. was so difficult to Ia.
cafe the scene of the explosion by the
sound was on account OF the echoes.
coming in from all directions. epcount.
erihS on its way many tall buildings. and
nelng so alf-pervasive, it was next to i'm.
possible for any one to locate IL ac
curately by ear
The way a person locates sound is to
near IL better in one ear than another
ana turn to the direction of the better
nearing. Ii sound happens dead ahead
or Dehind one will unconsciousIv turn
signify so that one ear can hear II
better than another But when the sound
rolls in from all directions the cars be.
rDf,N
come confused and no knowledge of d.
rection results
The enormous force exertod nv ,bis
explosion could he computed did one
Know the amplitude of the air wave and
me distance from the source. Il Is
simple matter in pure wave. for #
means merely the setting in motion of a
certain amount Of matter at a certain
rate. '"'h
How about the intensity of the wave
as IT went onward? The same mower
would be distributed over the surface Of
larger ana larger spheres, and some would
ne absorbed as it, went along. Leaving
out the absorption and echoes. then tho
intensity would decrease as the surface
OF sphere increases. which is as the
square or the distance. So a place two
mics away would get only one.fourth
the energy OF place one mile away. and.
everything else being equal, would eel
only one-fourth the damage.
The reflected wave. or echo, may be-
rejected again and again, even from one
side OF street to the other, but aware
getting less and less intense as It goes
along. The reflection depends to some
extent on the size of the reflectine CUR.
race, the surface having to be large
enough. FOR sound wave Of the size OF
the one caused by the explosion TO have
gotten good rcf1ection-one capable Of
doing any damage at a distance rathar
large surface, such as the side of a fouae.
would be necessary.