Evening star., 1941-10-17
German 'EIectron'
Fire Bomb Ranked
Highest in Efficiency
U. S. Chemical Warfare
Article Gives Details Of
Magnesium Weapon
By THOMAS 4. HENRY.

Details OF the German fire bomb,
described as "one Of the most II not
the most efficient bomb ever de-
vised" have just been described in
the United States Army Chemical
Warfare Service bulletin.
1t is known as the ~electron
bomb" Most information concern
ing 1t has come to the United States
through strictcensorship. 1t weighs,
according to report in the bulletin,
approximately 22 pounds. This
makes 1t possible for q single bomb
ing plane TO carry approximately
1000 bombs Hitherto, with the
heavy explosive bombs, this number
has been restricted to about so.
The one-kilogram electron bomb
makes use Of its thick-walled 80 per
cent magnesium shell 10 spread its
fire. This shell is approximately
inches in length and inches in
diameter. 1t contains several ounces
of thermite mixture. Unlike the
thermite type Of incendiary bombs
used during the last World War,
however, this thermite serves only
to ignite the magnesium shell. 1t is
not itself the main incendiary ma
terial
Fired by Needle Igniter.
The thermite reaction within the
shell is set of by an igniter on either
the nose or tail of the shell. This
igniter consists merely of a needle
which is driven into a small percus-
sion cap by the impact of the bomb.
Unlike other types Of bombs"
says the Chemical Warfare Service
report, by John A. West. IT., "the
electron bomb does not explode upon
impact but, rather, the thermite
reacts violently for nearly a minute
at a temperature Of about 1882
degrees Fahrenheit. Jets of flame
emit from vent holes in the shell
and bits Of molten magnesium which
are forced through these noles
scatter in every direction for a dis
tance Of about so feet. This scatter
ing Of incendiary material ends
when the termite reaction has been
completed and the pressure within
the bomb has been decreased. How
ever, the magnesium shell has been
ign1ted by that time and will burn
for 10 or IS minutes at tempera-
ture Of approximately 1912 degrees
Fahrenhelt, setting fire to any COM
bustlble material within a radius of
few feet.
The number Of those l-kilogram
electron bombs that a single bomb
ing plane can carry ranges from
1000 TO 1000. Assuming that onlv
IS per cent of the average urban
district is built over. out Of 1000
bombs only $50 would make direct
hits. OF this number it is likely that
half would either glance off roofs or
fall to penetrate because Of roof
construction. OF the $50 bombs
striking buildings, perhaps not more
than rs would be capable OF starting
serious fires.
Accurate Aim Impossible.
The area over which these rs fres
would be scattered would depend
upon the speed and height st
which the plane was flying and the
distance covered while it was drop-
ping its load. At 5000 feet, fyins at
200 miles per hour and dropping 20
electron bombs a second, the bonber
would spend its cargo of 1000 bombs
while moving only 3 miles, and set
fires approximately every so yards.
Owing to the Hghtness Of ths
electron bomb any degree OF ac-
cracy IN dropping it is impossible.
Twenty bombs dropped at the same
instant from 5000 feet might strike
anywhere within an area of l0O0o
square yards. Thus the use of this
bomb is reserved for indiscriminste
bombing only. Heavier bombs of
similar construction are used when
specific targets are sought such as
factories, supply bases and muni-
tions dumps"
water can be used to combat this
bomb, the report points out. bur
must be applied carefully. II ar.
celerates the burning of magnesium
but cuts down the burning time
from II to 2 or 8 minutes. If water
Is put on too fast there NAV be q
violent explosion. Sand and other
granular materials can be used tn
bring the electron bomb under con-
troll. The bomb should be thorouehlv
covered with the material until the
glare and heat have been reduced
when it is possible to SCOOP up both
WIN covering material and remove
tne whole into the open where the
oomo can burn itself out without
any great danger.