There is one field in which the airman has achieved distinctive
triumphs. This is in the guidance of artillery fire. The modern battle
depends first and foremost upon the fierce effectiveness of big-gun
assault, but to ensure this reliable direction is imperative. No force
has proved so invaluable for this purpose as the man of-the-air, and
consequently this is the province in which he has been exceptionally and
successfully active.
It will be recalled that in the Japanese investiture of Port Arthur
during the Russo-Japanese war, thousands of lives were expended upon the
retention and assault of 203 Metre Hill. It was the most blood-stained
spot upon the whole of the Eastern Asiatic battlefield. General Nogi
threw thousands after thousands of his warriors against this rampart
while the Russians defended it no less resolutely. It was captured and
re-captured; in fact, the fighting round this eminence was so intense
that it appeared to the outsider to be more important to both sides than
even Port Arthur itself.
Yet if General Nogi had been in the possession of a single aeroplane
or dirigible it is safe to assert that scarcely one hundred Japanese or
Russian soldiers would have met their fate upon this hill. Its value to
the Japanese lay in one sole factor. The Japanese heavy guns shelling
the harbour and the fleet it contained were posted upon the further
side of this eminence and the fire of these weapons was more or less
haphazard. No means of directing the artillery upon the vital points
were available; 203 Metre Hill interrupted the line of sight. The
Japanese thereupon resolved to capture the hill, while the Russians,
equally appreciative of the obstruction it offered to their enemy, as
valiantly strove to hold it. Once the hill was captured and the fire
of the Japanese guns could be directed, the fate of the fortress was
sealed.
Similar conditions have prevailed during the present campaign,
especially in the western theatre of war, where the ruggedness of the
country has tended to render artillery fire ineffective and expensive
unless efficiently controlled. When the German Army attacked the line of
the British forces so vehemently and compelled the retreat at Mons,
the devastating fire of the enemy's artillery was directed almost
exclusively by their airmen, who hovered over the British lines,
indicating exactly the point where gun-fire could work the maximum
of havoc. The instant concentration of massed artillery fire upon
the indicated positions speedily rendered one position after another
untenable.
The Germans maintained the upper hand until at last the aerial forces of
the British Expeditionary Army came into action. These airmen attacked
the Teuton aerial craft without the slightest hesitation, and in a
short while rendered cloudland absolutely unhealthy. The sequel
was interesting. As if suddenly blinded, the German artillery fire
immediately deteriorated. On the other hand, the British artillery,
now having the benefit of aerial guidance, was able to repay the
German onslaughts with interest, and speedily compelled that elaborate
digging-in of the infantry lines which has now become so characteristic
of the opposing forces.
So far as the British lines are concerned the men in the trenches keep a
sharp look-out for hostile aeroplanes. The moment one is observed to
be advancing, all the men seclude themselves and maintain their
concealment. To do otherwise is to court a raking artillery outburst.
The German aeroplane, detecting the tendency of the trenches describes
in the air the location of the vulnerable spot and the precise
disposition by flying immediately above the line. Twice the manoeuvre
is repeated, the second movement evidently being in the character of a
check upon the first observation, and in accordance with instructions,
whereupon the Tommies, to quote their own words, "know they are in for
it!" Ere the aeroplane has completed the second manoeuvre the German
guns ring out.
The facility with which artillery fire can be concentrated through the
medium of the aeroplane is amazing. In one instance, according to the
story related to me by an officer, "a number of our men were resting in
an open field immediately behind the second line of trenches, being in
fact the reserves intended for the relief of the front lines during the
following night. An aeroplane hove in sight. The men dropped their kits
and got under cover in an adjacent wood. The aeroplane was flying at a
great height and evidently laboured under the impression that the kits
were men. Twice it flew over the field in the usual manner, and then
the storm of shrapnel, 'Jack Johnsons' and other tokens from the Kaiser
rained upon the confined space. A round four hundred shells were dropped
into that field in the short period of ten minutes, and the range was
so accurate that no single shell fell outside the space. Had the men not
hurried to cover not one would have been left alive to tell the tale,
because every square foot of the land was searched through and through.
We laughed at the short-sightedness of the airman who had contributed
to such a waste of valuable shot and shell, but at the same time
appreciated the narrowness of our own escape."
The above instance is by no means isolated. It has happened time after
time. The slightest sign of activity in a trench when a "Taube" is
overhead suffices to cause the trench to be blown to fragments, and time
after time the British soldiers have had to lie prone in their trenches
and suffer partial burial as an alternative to being riddled by
shrapnel.
The method of ascertaining the range of the target from the indications
given by the aeroplane are of the simplest character. The German method
is for the aerial craft to fly over the position, and when in vertical
line therewith to discharge a handful of tinsel, which, in falling,
glitters in the sunlight, or to launch a smoking missile which answers
the same purpose as a projectile provided with a tracer. This smoke-ball
being dropped over the position leaves a trail of black or whitish smoke
according to the climatic conditions which prevail, the object being to
enable the signal to be picked up with the greatest facility. The height
at which the aerial craft is flying being known, a little triangulation
upon the part of the observer at the firing point enables him to
calculate the range and to have the guns laid accordingly.
When the aerial craft has been entrusted with the especial duty of
directing artillery-fire, a system of communication between the aerial
observer and the officer in charge of the artillery is established,
conducted, of course, by code. In the British Army, signalling is both
visual and audible. In daylight visual signalling is carried out by
means of coloured flags or streamers and smoke-signals, while audible
communication is effected by means of a powerful horn working upon the
siren principle and similar to those used by automobiles. Both flags and
sound-signals, however, are restricted owing to the comparatively short
distances over which they can be read with any degree of accuracy. The
smoke-signal therefore appears to be the most satisfactory and reliable,
as the German airmen have proved conclusively, for the simple reason
that the trail of smoke may be picked up with comparative ease, even
at a distance, by means of field glasses. The tinsel too, is readily
distinguishable, particularly in bright weather, for the glittering
surface, catching the sun-light, acts some what in the manner of a
heliograph.
The progress of the airman is followed by two officers at the base from
which he started. One is equipped with the director, while the
second takes the range. Directly this has been found as a result of
calculation, the guns are laid ready for firing. In those cases where
the enemy's artillery is concealed perhaps behind a hill, the airman is
of incalculable value, inasmuch as he is able to reveal a position which
otherwise would have to be found by considerable haphazard firing, and
which, even if followed by a captive balloon anchored above the firing
point, might resist correction.
The accuracy of the airman's work in communicating the range has been
responsible for the high efficiency of the British and French artillery.
The latter, with the 75 millimetre quick-firing gun, is particularly
adapted to following up the results of the aeroplane's reconnaissance,
especially with the system of rafale fire, because the whole position
can be searched through and through within a minute or two. According
to information which has been given to me by our artillery officers, the
British system also has proved disastrous to the enemy. The practice
is to get the range as communicated by the aeroplane, to bring the
artillery into position speedily, to discharge salvo after salvo with
all speed for a few minutes, and then to wheel the artillery away before
any hostile fire can be returned. The celerity with which the British
artillery comes into, and goes out of, action has astonished even
our own authorities. This mobility is of unique value: it is taking
advantage of a somewhat slow-witted enemy with interest. By the time
the Germans have opened fire upon the point whence the British guns were
discharged, the latter have disappeared and are ready to let fly from
another point, some distance away, so that the hostile fire is abortive.
Mobility of such a character is decidedly unnerving and baffling even to
a quick-witted opponent.
In his search for hostile artillery the airman runs grave risks and
displays remarkable resource. It is invariably decided, before he sets
out, that he shall always return to a certain altitude to communicate
signals. Time after time the guns of the enemy have been concealed
so cunningly from aerial observation as to pass unnoticed. This trait
became more pronounced as the campaigns of the Aisne progressed.
Accordingly the airman adopts a daring procedure. He swoops down over
suspicious places, where he thinks guns may be lurking, hoping that the
enemy will betray its presence. The ruse is invariably successful. The
airman makes a sudden dive towards the earth. The soldiers in hiding
below, who have become somewhat demoralised by the accuracy of the
British aerial bomb-throwers, have an attack of nerves. They open a
spirited fusillade in the hope of bringing the airman to earth. But
their very excitement contributes to his safety. The shots are fired
without careful aim and expend themselves harmlessly. Sweeping once more
upwards, the airman regains the pre-determined level, performs a certain
evolution in the air which warns the observer at his base that he has
made a discovery, and promptly drops his guiding signal directly over
the point from which he has drawn fire.
Operations at night are conducted by means of coloured lights or an
electrical searchlight system. In the former instance three lights
are generally carried--white, red, and green--each of which has a
distinctive meaning. If reliance is placed upon the electric light
signalling lamp, then communications are in code. But night operations
are somewhat difficult and extremely dangerous, except when the elements
are propitious. There is the ground mist which blots everything from
sight, rendering reconnaissance purely speculative. But on a clear night
the airman is more likely to prove successful. He keeps a vigilant eye
upon all ground-lights and by close observation is able to determine
their significance. It is for this reason that no lights of any
description are permitted in the advance trenches. The striking of a
match may easily betray a position to the alert eye above.
So far as the British Army is concerned a complete code is in operation
for communicating between aeroplanes and the ground at night. Very's
lights are used for this purpose, it being possible to distinguish the
respective colours at a distance of six miles and from an altitude of
2,000 feet. The lights are used both by the aeroplane and the battery of
artillery.
The code is varied frequently, but the following conveys a rough idea of
how communication is carried out by this means under cover of darkness.
The aeroplane has located its objective and has returned to the
pre-arranged altitude. A red light is thrown by the airman. It indicates
that he is directly over the enemy's position. A similarly coloured
light is shown by the artillery officer, which intimates to the airman
that his signal has been observed and that the range has been taken.
In observing the effects of artillery fire a code of signals is employed
between the airman and the artillery officer to indicate whether the
shot is "long" or "short," to the right or to the left of the mark,
while others intimate whether the fuse is correctly timed or otherwise.
It is necessary to change the code fairly frequently, not only lest
it should fall into the enemy's hands, but also to baffle the hostile
forces; otherwise, after a little experience, the latter would be able
to divine the significance of the signals, and, in anticipation of being
greeted with a warm fusillade, would complete hurried arrangements
to mitigate its effects, if not to vacate the position until the
bombardment had ceased.
Sufficient experience has already been gathered, however, to prove the
salient fact that the airman is destined to play an important part
in the direction and control of artillery-fire. Already he has been
responsible for a re-arrangement of strategy and tactics. The man aloft
holds such a superior position as to defy subjugation; the alternative
is to render his work more difficult, if not absolutely impossible.