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armour, which looked and was made up in the same way as that of five
hundred years before.
The infantryman soon needed a machine gun lighter than the Maxim,
Hotchkiss and Vickers (a British derivative of the Maxim), which were found
to be somewhat unwieldy in the front-line trenches. The first solution to this,
and for its time a very successful one, was the light machine gun developed by
the American Colonel I.N.Lewis, which was adopted by the British at the end
of 1914. The Lewis gun was gas operated, using a piston in the cylinder under
the barrel and a sliding and rotating bolt; it used drum magazines and weighed
only 12.7kg (28lbs) compared to the 31kg (68lbs) of the Vickers. It was also,
like the Vickers, adapted for aircraft armament. The French answer was the
Chauchat, also later used by the Americans, but this had a reputation for
mechanical unreliability and was replaced in the French army shortly after the
end of the war. The Americans produced the Browning automatic rifle (BAR),
which they would continue to use in the Second World War.
The most horrific weapon to be used during the war was undoubtedly gas.
The use of burning sulphur to give off noxious gases had been known about in
ancient times, and during the latter stages of the American Civil War ‘stink-
shells’ to give off ‘offensive gases’ were considered. There is evidence that the
Japanese used burning rags impregnated with arsenic against the Russians in
1904–5. The use of poisonous gas in war had been banned by the Hague
Conventions of 1899 and 1907, but this did not deter the Germans from
beginning to experiment with it in late 1914. This work was spearheaded by
Dr von Trappen, assisted by Professor Fritz Haber, famous for the Haber
process (see pp. 223–4). They looked initially at irritants, especially xylyl
bromide, a tear-producing agent, using artillery shells as the means of delivery.
The first significant use of it came in the German offensive against the
Russians at Lódz at the end of January 1915 when, because of the cold
weather, the liquid froze instead of evaporating as it should. The Germans next

turned to chlorine and discharged it from cylinders at the onset of the Second
Battle of Ypres in April 1915. Chlorine attacks the lungs and the initial results,
against French colonial troops, were devastating, creating wholesale panic. The
situation was eventually restored, with British and Canadian troops wrapping
wet cloths over their faces. Urine was used and provided some protection
because the ammonia in it had a neutralizing effect on the gas. Proper gas
masks were quickly produced. The first type was a flannelette bag impregnated
with phenol, with a celluloid eye-piece. Later in the war came the box
respirator, which was more comfortable to wear and operate in.
The British retaliated at Loos in September 1915, but here there were
problems in that the wind was not sufficiently strong in all sectors to blow the
gas into the German lines. As a result, both sides came to favour the artillery
shell over cylinders as a delivery means. New types of gas gradually appeared. In
June 1915 came lacrymatory gas, followed in December by phosgene, which,
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like chlorine, is a choking agent but more difficult to detect. Then, in 1917, came
perhaps the most unpleasant of all, mustard gas (dichlorodiethyl sulphide), a
blister agent. Blood agents such as hydrogen cyanide and cyanogen chloride,
which attack the enzyme in the red blood cell, were also developed.
Almost as unpleasant as gas was the flamethrower, again not a new idea,
having been used by the Byzantines 1100 years previously. The French
experimented with it in 1914, but the first significant use was by the Germans
against the British at Hooge at the end of July 1915. These Flammenwerferen
were portable, with the drum containing a mixture of oils strapped to the
operator’s back. The system was operated by means of compressed air, with
the liquid being ignited at the nozzle of the tube. Later the British, with their
Livens projector, developed a means of firing cans of oil mixed with cotton
waste using high explosive, with a time fuse set to detonate them at target end
and scatter burning cotton waste over a wide area.

It was inevitable that the internal combustion engine would have an
influence on the conduct of warfare, but, in many ways, its influence was
gradual rather than dramatic. The armies did increasingly use mechanical
transport, but even by the war’s end they were still heavily reliant on the horse.
Nevertheless, thought had been given to armed and armoured motor cars in
the 1890s, and early examples were a design for an armoured car with two
machine guns by the American E.J.Pennington in 1896 and the ‘Motor Scout’
by the British engineer F.R.Simms in 1899. During the 1900s various
European countries produced prototype models and the Italians actually
deployed armoured Fiat lorries during their war against the Turks in Libya in
1911, but it was not until the outbreak of war in 1914 that serious attention
began to be paid to them. The French and Belgians fielded models based on
Renault, Peugeot and Minerva chassis, while the Germans and Austrians had
Daimlers, Büssings and Ehrhardts, the last-named with four-wheel steering.
The first British armoured cars used were created in France from normal
touring models with ship’s plate incorporated as armour and were used by the
Royal Naval Air Service to guard forward landing grounds, but soon standard
designs were produced, foremost of which was the Rolls-Royce armoured car,
which fought in every theatre and lived on to see active service in North Africa
in the early years of the Second World War. Armoured lorries were also
developed to carry QF guns, especially for use against aircraft, and motor-cycle
combinations carrying machine guns were used.
Trench warfare understandably limited the employment of wheeled
armoured fighting vehicles and brought about the birth of the tank, a British
invention. No single individual can claim to have invented it, although an
Australian called de Mole did take out a patent in 1912 for a vehicle which
was remarkably similar in concept to the early British tanks. The requirement
evolved by the end of 1914 was for a machine based on the ‘caterpillar’
tracked system (tracked traction engines for pulling heavy agricultural
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machinery had been developed before the war; (see Chapter 16)) which could
overcome barbed wire, cross trenches and was armed with machine guns. By
mid-summer 1916 the Mark 1 was in production and the first models shipped
to France in August. They were originally called landships, and the name
‘tank’ was adopted as a security measure. The Mark 1, with a crew of eight,
weighed 28.5 tonnes and was powered by a 6-cylinder 78kw (105hp) Daimler
engine with a top speed of 6kph (3.7mph). The ‘male’ version had two
sponson-mounted 6-pdr naval guns and four Hotchkiss machine guns, while
the ‘female’ had five Vickers machine guns and one Hotchkiss. Besides the
driver, it required two men to operate the gears. Enormous heat built up
inside, which added to the crew’s difficulties, and breakdowns were frequent.
Nevertheless, it made its battlefield debut on the Somme on 15 September
1916 and took the Germans by surprise. The British produced further, more
mechanically reliable models with the same rhomboid shape. The French, too,
produced the heavy St Chamond and Schneider, and the very successful light
7-tonne Renault. The Italians also produced two Fiat heavy tank prototypes.
The German answer was the A7V, but because of a shortage of raw materials
during the last part of the war, few were built. The first tank against tank
action took place between three British Mark IVs and three German tanks on
26 April 1918 at Villers Bretonneux. Other portents for the future were the
development of self-propelled artillery guns on tank chassis and command
tanks equipped with wireless. There is no doubt that the tank made an
important contribution to the eventual Allied victory, but it was too slow and
cumbersome to be decisive in its own right.
The Germans recognized very quickly the importance of developing
effective anti-tank weapons. They were initially lucky in that they had had
in service since 1915 the ‘K’ bullet, with its tungsten-carbide core, which
could penetrate the steel plates used to protect snipers and sentries in the
front line, and they found that it would penetrate the early tanks until the

British produced thicker armour. The next stage was the anti-tank rifle, and
this came into service as the Mauser ‘T’ 13mm (0.5in) calibre rifle of late
1917. They found that the light trench mortar was also effective, but the
greatest threat to the tank became the German 77mm (3in) field gun using
a steel pointed armour-piercing shell. In 1918 the British produced the No
44 rifle grenade filled with amatol, but no evidence exists as to how
effective this was, while the French had the 37mm (1.45in) Puteaux gun
firing solid shot.
Air warfare
The aeroplane introduced a new dimension to war. While initially the prime
role of the aircraft was reconnaissance, its use as a bomber began early with
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British attempts to bomb the German Zeppelin bases in autumn 1914
because of fears that they would attack Britain. First attempts to arm aircraft
were very ad hoc, with rifles, pistols, grenades and even darts being used, but
proper machine guns were mounted as both sides realized the need to
achieve air superiority over the battlefield. The main technical problem was
how to achieve a forward-firing machine gun which would not damage the
propellor blades. Early solutions were steel deflector plates fixed to the blades
and the British concept of the ‘pusher’ aircraft, with the propellor mounted in
the rear, as exemplified by the Vickers FB
5
Gunbus. The breakthrough came,
however, with the development of the interrupter gear by the Dutch aircraft
designer Anthony Fokker. This synchronized the firing of the machine gun
with the position of the propellor blades—it only fired when they were at the
horizontal. He fitted it on his Fokker fighter and for a time the Germans
were dominant in the air until the Allies produced a similar system, the
Constantinesco ‘cc’ interruptor gear. The beginning of strategic bombing

came with the Zeppelin raids on England in 1915, and this was followed by
attacks by aircraft two years later. The Allies retaliated, although the physical
effects were a mere fraction of what they would be 25 years later. Bombs,
high explosive in soft metal casings, designed to detonate on impact,
increased in size from 20lb (9kg) to 230lb (104kg) as the war progressed and
aircraft payloads became larger. It was also the air war which largely brought
about the introduction of the tracer round so that pilots could correct their
fire, and incendiary ammunition for use against observation balloons.
Experiments using aircraft-mounted rockets against balloons were also
carried out.
The threat of the aircraft brought about the need for air defence weapons.
In the main, these were normally converted field guns, which were mounted
on a platform in order to incorporate 360° traverse and an elevation of 80° or
90°. Spring catches had to be inserted in the breech in order to prevent the
round from slipping out before the breech-block was closed when loaded at
high angles, and recoil systems had to be strengthened. The problem of
accurately gauging the speed and height of aircraft was overcome by the
‘Central Post Instrument’ or Tachymeter devised by a French inventor, Brocq.
This consisted of two telescopes, one to track the target’s height and the other
its course. The observers rotated them with cranks connected to a generator
which emitted a current proportional to the speed of tracking, with height and
speed being reproduced on dials from which the predicted position of the
aircraft could be calculated through using a resistance equivalent to the shell’s
time of flight. To provide early warning of an aircraft’s approach, sound
detectors were developed, and by 1918 an aircraft could be detected over five
miles (8km) away.
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Naval warfare
In 1914 the war at sea was still primarily a matter of bringing the enemy’s fleet

to battle and destroying it. To this end, the main maritime weapon was the
battleship, and typical of this was the Royal Navy’s Queen Elizabeth with her
15in (380mm) guns. Yet, while the British were successful in keeping the
German Grand Fleet in harbour for much of the war, thanks to the Battle of
Jutland in May 1916, the battle demonstrated that the Germans had superior
sighting equipment and that the quality of the British armoured steel plate was
inferior. There were, however, two other naval weapons which really came of
age during 1914–18, the torpedo and the mine.
In naval parlance a mine is a weapon designed to explode against a ship,
and in this sense there was and is no difference between the mine and torpedo.
The first serious attempt to produce an effective mine was by an American,
David Bushnell, during the American War of Independence (1775–83). He
constructed a one-man submarine which carried a watertight keg containing
some 150lb (68kg) of gunpowder. This could be released from inside the
submarine and had a handscrew for attaching it to the target ship. Releasing
the keg set a clock running in the submarine and this enabled the operator to
get his vessel clear before the gunlock mechanism on the charge was actuated.
Unfortunately, although his submarine was successful in getting close to
British warships on a number of occasions, their bottoms proved too tough for
the handscrew to penetrate. He also designed a floating mine, consisting of a
gunpowder keg on a log float with an ingenious trigger-operated device, but
this met with only very limited success. Robert Fulton, another American and
contemporary of Bushnell, also used the submarine concept, in which he tried
to interest both the British and French during the Napoleonic Wars. The
inventor of the Colt revolver also invented an ingenious system for electrically
detonating moored mines and in a trial sank a ship at 6.4km (4 miles) range.
This idea was taken up by the Prussians during their war with Denmark
1849–50 and the Russians during the Crimean War (1854–6). At the same
time a detonation system for the moored contact mine was invented by the
father of Alfred Nobel which would remain in use for the next 100 years. This

was made up of a hollow lead horn on the outside of the mine which enclosed
a mixture of sugar and potassium chlorate, together with a glass phial filled
with sulphuric acid. If a ship struck the mine and bent the horn the phial
would break and the resultant chemical reaction produced a flame sufficient to
detonate the gunpowder charge.
The American Civil War saw many types of mine used, including Nobel-
type chemical fuses and electrically detonated mines. Bushnell’s submarine
concept was also used in the form of the ‘David’, a small hand operated semi-
submersible craft carrying an explosive charge, later types being steam driven.
Two types of torpedo were also used. The first was the ‘spar’, which was an
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explosive charge on a pole suspended over the bows of a small vessel, which,
on approaching the target was lowered on a wire and detonated through
contact with the hull. It was successfully used against the Confederate ironclad
Albemarle in 1864. The second type was the ‘towing’ torpedo, which was towed
by a boat but at a 45° angle rather than directly astern, for obvious reasons.
Just after the American Civil War the first self-propelled torpedo was invented
by Robert Whitehead. It was driven by a compressed air engine and had two
contra-rotating screws to keep it on course, as well as a hydrostatic pressure
system to keep it at the correct depth. It did have a number of teething
problems, but its first successful use in war came in January 1878 when the
Russians, using two Whitehead torpedoes, sunk a Turkish ship in Batum
harbour. The new explosives developed by Nobel helped to perfect the torpedo
because of their greater power than gunpowder, and very soon torpedoes were
being used in two different ways, fired either from a submarine or by a new
type of surface warship, the torpedo boat destroyer.
During 1914–18 the sea mine underwent several further refinements. They
could either be anchored to the seabed by a weight, or be free floating. In the
latter case, various types were used. There were drifting mines suspended from

a float, creeping mines on the end of a chain that dragged along the sea
bottom, and the oscillating mine, which used a hydrostatic valve to vary its
depth below the water surface. Later in the war an ingenious anti-submarine
mine, the antenna mine, was developed by the British. This was moored at a
depth of some 15m (soft), with a I2m (40ft) copper antenna suspended on top
of it by means of a float. If this contacted the steel hull of a submarine or
surface vessel it created a sea cell through a copper element within the mine
and this fired the electrical detonator.
The war quickly showed that it was the submarine rather than the surface
launched torpedo which was the greater threat, and this was dramatically
brought home by the sinking of three elderly British cruisers within 75 minutes
by the German U-9 on 22 September 1914. The torpedo, too, had become
more efficient, especially as a result of the adoption of the gyroscope for
directional control by the Austrian Ludwig Obry in 1895. Greater range was
also achieved by the use of alcohol or paraffin as a fuel. The threat became
especially severe to the British in 1917 when the Germans embarked on
unrestricted submarine warfare against merchant shipping and ways had to be
found to defeat the menace. The adoption of the convoy system was one, and,
apart from the antenna mine, two other methods of destroying the submarine
under the surface were the paravane charge, which was towed behind a surface
vessel in the hope that a submarine might hit it, and the more effective depth
charge which made its first appearance in 1914, although it did not achieve
any results until two years later. It was, in essence, a mine launched by a
thrower and set, through a hydrostatic fuse, to detonate at a certain depth,
usually 25m (80ft). The submerged submarine still had to be detected,
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however, and a solution to this was not found until 1918 with the invention of
ASDIC, named after the Allied Submarine Detection Investigation Committee
and later called sonar (Sound Navigation and Ranging) by the Americans.

This consisted of a radio transmitter/receiver, which transmitted sound
impulses. If these hit a solid object they would be reflected in the form of an
echo or ‘ping’. From the transmission-reception time interval the range to the
submarine could be worked out and depth charges set accordingly. Anti-
submarine warfare had arrived.
THE SECOND WORLD WAR
Air warfare
There was a widely held belief between the two world wars that warfare in
the future would be dominated by the bomber aircraft and the gas bomb.
The early First World War attempts at strategic bombing, although they may
not have caused much physical damage, did have a significant effect on the
morale of civilian populations. Attacks on them and centres of government
would, it was argued, quickly lead to surrender. For a number of reasons this
did not happen.
The horrific effects of gas had led to its banning as a weapon of war by the
1925 Geneva Protocol. Nevertheless, during the 1930s the Germans did
develop a new form of agent, nerve gas, designed to attack the nervous system
and more lethal than existing types, in the shape of Tabun and Sarin. Neither
side, however, used gas in 1939–45, more for fear of retaliation than because it
was banned.
As for the bomber, the argument that it was invulnerable to attack because
fighter aircraft would not be able to intercept it before it arrived over its target
was proved groundless for two reasons. The first was the development of the
monoplane fighter, largely thanks to the Schneider Trophy races, with its much
higher performance than biplane types, and with wing mounted multiple
machine guns. Not only could it climb and fly very much faster, but it also had
the necessary firepower. Even so, the fighter still had to have sufficient warning
of the bomber’s approach and sound locating devices were not enough.
The answer lay in radar. This is based on the principle that all solid and
liquid bodies reflect radio waves, and was originally called ‘radiolocation’ by

the British. The first experiments were carried out in 1924 by two Cambridge
scientists, Appleton and Barnett, who investigated the measuring of distance by
this means and their methods were used to identify the Heaviside Layer, the
electrified conducting region in the upper atmosphere which causes downward
refraction of radio waves and is called after the physicist who first forecast its
existence. A radio transmitter sending out short pulses of radio energy was
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then devised and was incorporated in VHF radio telephone links. It was
noticed that aircraft could be detected through the reflection of these pulses,
and in 1935 Sir Robert Watson Watt began work to apply radiolocation to
military purposes. Very soon he was able to detect an aircraft and represent its
presence by ‘blips’ on a cathode ray tube, with the transmitter automatically
shutting itself off after it had transmitted a pulse to enable the receiver to
identify the reflection. Height was measured by comparing the receiving signal
on two vertical aerials placed a known distance apart. In order to be able to
locate the aircraft accurately, its bearing had also to be measured, and this was
achieved employing the same principle, but using a comparison of the received
signal detected by two crossed aerials. The system was now called RDF or
radio direction finding, but was later changed to the American acronym radar
(Radio Direction and Ranging).
From 1936 the British began to set up a continuous chain of radar stations
known as the ‘Chain Home’ network and this eventually provided complete
coverage of the coastline. Proof of its effectiveness came during the Battle of
Britain in 1940. The information on German bomber streams detected by the
radar stations was passed back to controllers, who were then able to direct
fighters into the air and, using radio, guide them on to the approaching
bombers. The Germans, too, during 1940–2, built up a similar chain across
north-west Europe, which was called the Kammhuber Line after the Luftwaffe
general responsible for installing it.

It soon became clear that radar could be applied to many other uses. It was
installed in night fighters in order to detect hostile aircraft when airborne. It
became a vital weapon in the war against the U-boat, complementing sonar in
that it could detect submarines on the surface. Early models merely had an
audio display, but later a cathode ray tube was incorporated. There were also
airborne submarine detection radars, and a type similar to this was used by
Allied bombers as a navigation device: here, different types of terrain produced
different echoes, which could be represented on a visual display tube, a system
known as ‘Home Sweet Home’, more commonly abbreviated to H2S. Another
system, OBOE, had two ground transmitters. One, the ‘cat’ sent out a signal
to an aircraft which enabled it to fly on a line of constant radius from the
transmitter, while the other, the ‘mouse’, aimed its signal to the target, which
was on the line of constant radius from the ‘cat’. In this way the bomber could
accurately attack the target in conditions of poor visibility. The Germans
employed a similar system, called Knickebein.
The main problem with radar was that it was an ‘active’ system, which
meant that it could be detected and jammed. Thus, German U-boats were
equipped with a Metox receiver, which would warn them when an aircraft
using radar was in the vicinity, and German night fighters could locate and
attack Allied bombers using radar detection devices. The most effective means
of jamming radar was simple in the extreme, consisting of strips of aluminium
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foil dropped by aircraft. These created a ‘snowstorm’ effect on visual displays.
Originally codenamed WINDOW, it is now known as Chaff and is still much
used as a defence against radar-guided missiles.
Radar as a navigation aid only came into service during the second half of
the war. At the outbreak, British and German bomber crews relied on dead
reckoning which was very inaccurate. Bomb aiming, too, was an imprecise
system, still using First World War bombsights which relied on the aircraft

flying straight and at constant speed over the target, by no means easy under
fire. Only with the introduction of gyroscopes into bombsights was a reliable
system introduced. The size of bombs increased as the war went on. From
the 500lb (227kg) bomb of 1939, the British in March 1945 used the
22,000lb (9975kg) Grand Slam to destroy the Bielefeld viaduct in Germany.
Some bombs were thin cased, relying on blast for their effect, while others
had thick cases and streamlined shape and were designed to penetrate and
fragment. There were also incendiary bombs, some filled with inflammable
liquid, others, usually small, using magnesium alloy. Yet, in spite of the
increasing weight of the Allied strategic bombing offensive, the German
people never did succumb to it as the pre-war theorists and many airmen
believed that they would.
Naval warfare
Radar played a large part in the war at sea, especially in the Battle of the
Atlantic against the German U-boats, and other weapons were employed on
both sides. By 1939 the torpedo, which could now be air- as well as surface
and subsurface launched, was driven by compressed air and diesel. Detonation
was either on contact with the target or by magnetic proximity, whereby the
increased magnetic field induced by an all-metal ship would activate a pistol in
the torpedo. This latter system, however, had several problems during the first
years of the war and took time to perfect. Towards the end of 1942, the
Germans introduced a new type, the Fat, in order to increase the chances of
hitting a ship when attacking a convoy. This was electrically driven and could
be set to circle to left or right. The next stage was the acoustic torpedo, which
homed in on the noise of the ship’s propellers. The Germans called this Falke
(=hawk). U-boats also had listening devices incorporated, with receivers built
into the hull, so that ships could be detected when the U-boat was submerged.
In order to counter sonar, the Germans developed both a rubber skin over the
hull, in order to dampen the echo, and a decoy in the form of a cylinder filled
with calcium hydride, which could be fired from a torpedo tube and floated

under the water to deceive the sonar while the U-boat made its escape.
On the Allied side, besides radar and sonar, an important detection device
was High Frequency Direction Finding (H/F D/F or ‘Huff Duff’). This was
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both shore and ship based and detected U-boat radio transmissions, giving a
bearing on them. Two sets operating in conjunction could pinpoint a U-boat’s
position. A further and highly significant weapon, as it was in many other
aspects of the war, was the Allied ability to decipher the top secret German
codes employed with the Enigma cipher machine, which often gave prior
warning of the intentions of the U-boat ‘wolf packs’. Depth charges could be
dropped by aircraft, as well as launched from a ship. Amatol, minol and torpex
were the explosives used, and these were detonated by a preset hydrostatic
pistol. A variant of this was the ‘Hedgehog’, which launched a pattern of 24
projectiles, each filled with 14.5kg (32lb) of torpex, but would only explode on
contact with a solid object. The most significant antisubmarine weapon,
developed by the Americans in 1942, was Fido, an aerially launched acoustic
homing torpedo.
Mention must be made of a particular branch of science which played an
important role in the Battle of the Atlantic. Operational Analysis is an
observational, as opposed to experimental, science which uses accumulated
data to construct a mathematical model in order to aid problem solving and
decision making. The father of the concept was F.W.Lanchester, who first used
this technique in 1916 in order to evaluate the most efficient use of aircraft in
war. Operational Analysis was used during 1939–45 to find answers to such
questions as the best method of searching for a submarine, optimum depth
charge settings and the best colour to paint anti-submarine aircraft to minimize
visual detection by submarines. Employed also in many other aspects of the
war, Operational Analysis continues to play a major part in the formulation of
requirements for new weapons systems.

Mines, like torpedoes, became increasingly sophisticated as the war
progressed. One type developed by the British just before the war followed the
original Bushnell concept of a mine which was attached to the hull of the
target ship. The limpet mine was disc-like in shape, containing 1.8–4.5kg (4–
10lb) of blasting gelatin, and had a time fuse which could be set from a period
of thirty minutes up to five hours. It was attached to the hull by magnets and
many successes were scored with it. At the outbreak of war the Germans
began using an ingenious parachute mine. The parachute was used to control
the speed of descent so that on hitting the water an arming clock was started.
As the mine sank, a spring-loaded button in the side operated as a hydrostatic
switch, which stopped the clock when it reached a certain depth. This acted as
an anti-handling device, for once the mine was raised to this depth, the arming
clock would restart and run for half a minute before detonation. As it was,
once the mine touched bottom an electrical circuit was completed and the
mine came alive, ready to detonate under the influence of a ship’s magnetic
field. The counter to magnetic mines was to pass electric cables round the
ship’s hull, connect them to her generators and induce a magnetic field to
cancel out that of the ship. This was called degaussing after Karl Friedrich