A bomb is a container filled with an
explosive, incendiary matter, or gas that can be
dropped, hurled, or set in place to be detonated
by an attached exploding device. It may range in
design from a homemade device used by
terrorists, assassins, or clandestine raiders to a
sophisticated weapon of war. The original bomb,
an ancestor of the hand-thrown GRENADE, was
a simple container filled with black powder (see
GUNPOWDER), which was set off by a fuse lit
by the thrower. In the 16th century, the Dutch
invented a more sophisticated version, the
MORTAR bomb, a round iron container filled
with black powder that was set off when a fuse
was ignited by the detonation of a propelling
charge in the base of the mortar tube. By varying
the length of the fuse, the bomb's time of
detonation could be adjusted; thus, a bomb could
burst in air. These bombs were predecessors of
the ARTILLERY shell fired from a field gun with
rifled bore. In the 20th century the aerial bomb
became the most important adaptation of the
weapon. Its construction is similar to that of the
artillery shell. The conventional aerial bomb
consists of an explosive or chemical agent in a
container, one or several fuse-and-igniter
mechanisms, and external fins for directional
stability. Bombs dropped from high-performance
aircraft have an advanced aerodynamic shape.
The ultimate category of bomb is that utilizing
nuclear material as the explosive ingredients--the
the NEUTRON BOMB. 20th-Century Military
Use The advent of the airplane in warfare led to
the development of new types of bombs. The first
massive aerial bombing took place in 1915 when
German zeppelins carrying more than two tons of
bombs began dropping "terror from the skies" on
the British Isles. In the early stages of World War
I, airplane pilots had their hands full just flying, and
bombing was relegated to observers who merely
tossed small bombs over the side. Aircraft
engineering advanced, however, so that by 1918
multiengine bombers had become a reality and
450-kg (1,000-lb) bombs were in production.
The next major step in the development of aerial
bombing took place on July 21, 1921. Gen. Billy
MITCHELL, a champion of military airpower,
was finally allowed to test his theory that aircraft
carrying bombs could sink major naval units, a
theory that naval officials had considered
ridiculous. On that date, in the first of three such
demonstrations, the captured German
dreadnought Ostfriesland was sunk in minutes by
U.S. Army Air Corps bombers dropping 900-kg
(2,000-lb) bombs. Warfare had been
revolutionized; seapower was in jeopardy. During
World War II, aerial bombardment was
perfected. Massive raids, first by Germany and
then by the Allies, demonstrated the devastating
power of the conventional aerial bomb. As aircraft
size and performance increased, so did bomb size,
ending in the 10-ton (9,900-kg) British
"Earthquake" bomb. Incendiary bombs containing
thermite, a mixture of iron oxide, powdered
aluminum, and magnesium, were dropped nightly
by the thousands to cause fires. Other bombs
were manufactured for exacting tasks; one of the
most unusual was the Wallis "skipping bomb,"
used against German reservoir dams. Others, such
as the British "Tall Boy," were designed to destroy
massive concrete slabs. During the closing stages
of the war, Germany sent more than 8,500 V-1
guided bombs flying across the English Channel to
fall on England. A quantum jump in bomb
manufacture and use occurred in 1945 when U.S.
planes dropped atomic bombs to destroy two
cities, HIROSHIMA (Aug. 6.) and NAGASAKI
(Aug. 9). The bombings led Japan to surrender
and initiated a new era characterized by
NUCLEAR STRATEGIES on which the survival
of whole countries depended. Along with the
development of the high-yield nuclear weapons,
new types of tactical bombs have been developed.
Small antipersonnel and antivehicle bombs, called
bomblets, have been perfected. NAPALM, a
petroleum-jelly incendiary mixture, is an ingredient
used worldwide in tactical bombs.
Experimentation continues with fuel-air explosive
bombs made by dispensing an aerosol mixture of
fuel and air in cloud form and igniting the mixture.
Handmade Bombs The ability to produce simple
bombs has been central to the conduct of guerrilla
and terrorist warfare. Such a bomb can be as
simple as a stick of DYNAMITE with a blasting
cap. The development of plastic explosives during
World War II, however, has enabled terrorists to
produce bombs that are difficult to detect (they
have been smuggled aboard airplanes, for
example) but that have tremendous explosive
power. Letter and car bombs--plastic charges
triggered to explode by the opening of an
envelope or the turning of an ignition key--are
fairly simple bombs. More sophisticated
handmade bombs may use electronic timing and
triggering devices. Using knowledge gathered from
many different public sources, it is conceivable that
terrorists could build a small atom bomb, fueled by
purchased or stolen weapons-grade uranium. In
1975 the United States set up the Nuclear
Emergency Search Team (NEST) to counter
potential A-bomb threats.