THE AIRPLANE IN THE WORLD WAR
Picture to yourself a scene outside one of the Allied hangars or
airplane sheds, just back of the front lines, while the Great War is in
progress. It is early morning, gray and chilly. Small fighting machines,
which their trusty mechanics have carefully gone over for the tiniest
flaw, now stand ready to take to the air. Pilots, wrapped in their heavy
clothing--leather jacket, helmet and overcoat, gloves, goggles and
muffler--prepare to face the frigid atmosphere above the clouds. The
whirr of the motor, a short run over the ground, and up they go, one by
one, until they become so many blackbirds, driving and looping and
skimming through the sky. Over in this corner is a large reconnaissance
machine, with pilot and observer, waiting to ascend. It is one of a
squadron that will fly over the German lines to take photographs of the
enemy's positions. With its rapid-firing machine guns it is prepared to
give battle to the swifter enemy craft that will flash out to challenge
its onward flight. Its rôle is a difficult one. It cannot climb to
safety as the fighting machine can do and then swoop down on its enemy
from a favorable height. Its duty is to bring back accurate views of the
territory on the other side of No Man's Land. No matter what the
dangers, it must fly straight on, sticking close enough to earth to
accommodate its camera's range, and deviating as little as possible
from its course, though the enemy's speed scouts blacken the air with
bullets and the anti-aircraft guns spit at it maliciously from below.
All the machines in the squadron may not return, and there will be
vacant chairs at the dinner table to-night when those pilots who have
braved the stern hardships of the day relate their little experiences
with the Hun. But those who do come back will bring information which
will enable the Allied commanders to plan with intelligence the next
move in the battle that is raging.
A tour of inspection would disclose still other machines, large and
small, each designed and equipped for its special duties over the lines.
There are heavy, slower-flying day "bombers," and--silent this morning
but waiting patiently for the curtain of night to descend,--enormous
night bombing machines, the fiercest and hugest of all the great birds
of the flying force. To-night, under cover of darkness these machines
will speed upon their way, far over the enemy's lines. They carry fuel
for a journey of many hours' duration, and heavy bombs which they will
drop upon railway junctions, ammunition factories, staff headquarters
and important positions deep in the territory of the Hun. Before they
turn their noses homeward they will have crossed over the borders of
Germany, and along their silent course fires will shoot up and enemy
supplies and storehouses will be smoldering ruins when day breaks.
Unlike the night bombing machines of the Germans these great Allied
aircraft will not drop their missiles upon open towns along the Rhine,
nor will they leave behind them any toll of little children and
civilians maimed and killed by their brutality. Their instructions are
to bomb military objectives only, and when they have done that they will
fly back silently through the night, passing over quiet villages and
towns, where the sleeping inhabitants never will know that the great
blackbirds have hovered so close to them.
When the War broke out airplanes were not planned so carefully nor
equipped so fully for their special duties as they are to-day. Nobody
foresaw exactly what those duties would be, and nobody once dreamed that
the battalions of the air would play the tremendous rôle they have
played in deciding the great struggle. Even Germany, who had been
secretly planning and working and preparing for so long, had very little
conception of the actual importance of her heavier-than-air machines.
She neglected to use them entirely when she began her swift stride
across Belgium. That piece of neglect lost her the prize, for the plucky
Belgians, seizing the opportunity, marshalled their air forces, a small
handful of airplanes, and used them to good advantage in discovering the
intentions of the enemy. By means of her air force, Belgium was enabled
to hold back for awhile the onrushing tide of the Hun armies, until
France could bring her men into the field and the "contemptible little
army" of Britain could be hurried across the Channel.
As the air forces were the deciding factor in that first great
onslaught, so they have remained during the whole struggle. They began
as mere scouting machines, but they have taken upon themselves more and
more duties, until at the present time they are used for a multitude of
purposes, and are fitted with the most perfect equipment to carry out
their various ends.
Airplanes have often been called the "eyes of the army," but in war it
is not sufficient to be able to _see_ what the enemy is doing or is
about to do. You must also be able to keep him from knowing what your
plans are. So, there are the machines whose duty is to "see" and those
whose duty is to "put out the eyes of the enemy." These latter must keep
an eternal vigilance over the lines, on the lookout for enemy craft.
When one is spotted they dash out after it, pursue it back to its lines
and prevent it from performing its mission of reconnaissance. Nor are
they satisfied merely to drive it off, they follow and give fight. Over
there against the sky you see a little puff of smoke and flame that goes
shooting down to the horizon. It is an enemy plane that will never again
come spying upon Allied troops. Perhaps a group of fast German fighting
machines dart out unexpectedly to avenge it, and then there is a
terrible battle in the clouds, with every machine that is in the air
hurrying to the skirmish. You try to follow their swift movements as
they loop and dart and dive, but all you can see is a rapid confusion of
wings, and now and then a machine that separates itself from the general
mêlée and goes crashing to earth.
Not the least dangerous of the many services the airplane is performing
is that of the artillery "spotter." It belongs to some particular
battery whose guns are thundering away at the enemy. Hovering above No
Man's Land, where its position is a trifle too exposed to be
comfortable, it radiographs back to the gunners the exact locations of
important objectives, then watches the firing and reports the results.
Thanks to it the big guns do not speak in vain, and almost every shot is
a direct "hit."
And then there are the dreadnaughts of the sky who actually take part in
an attack, flying low over the lines and attacking the enemy infantry
with guns and with death-dealing bombs. They must run the gauntlet of
the enemy's fire, but on the other hand they spread terror and confusion
in the ranks of the soldiers massed below, distracting their attention
and leaving them open to the surprise of a sudden onslaught of Allied
troops.
There are other machines which help in an attack by keeping the various
parts of the long line in close communication with each other, so that
all efforts are in unison. Their duties correspond in a way to those of
the swift horseback rider we read of in the stories of old wars, who
sped with news of great import from one commander to another. Only that
the airplanes of to-day are so much more efficient than the gallant
horseback rider of old, that although the line stretches across a
nation, it can act as a man when the moment comes for a big "push."
Long before the war Germany had been busy turning out airplanes in
large numbers in her factories, and in August, 1914, her air force was
far superior in numbers to that of her great opponent France. She fondly
imagined that she would be able with the greatest ease to put out her
enemy's eyes, but in this she failed utterly. In spite of her military
program of construction, according to which airplanes were turned out as
if by clock-work, there was something wrong with her calculations. It is
amusing to look back and see how German "method" had been carried to the
absurd point of defeating itself. In manner truly characteristic, the
Hun had standardized his airplane down to the last bolt. Every machine
turned out was of exactly the same pattern, and built up of exactly the
same parts--parts which could be manufactured in large quantities and
put together with unusual speed. It was certainly _system_ raised to the
_n_th degree. And the machines themselves were good enough--sturdy
biplanes intended to be maids-of-all-work over the front lines. Yet in a
little while after the fighting had begun, Germany withdrew them in more
or less chagrin, and set herself to constructing others of varied
patterns. They were well made and splendidly equipped, but they were not
sufficiently _specialized_ for the many different kinds of work they
were called on to perform.
France had a motley array of airplanes of every size, shape and make
when the war broke out. They had varying systems of control, so that a
pilot who flew one with ease was nothing more than a novice when he
stepped into another. He did not know how its new set of levers
operated, nor how the plane would behave in the air. Moreover, the parts
for these French airplanes and for their engines had been specially
designed by each maker, and were quite unsuitable for any other type of
machine. The result was that when a machine had to be repaired at the
front, it was "laid up" for a long time, while the special part it
required was being ordered and made for it. When finally it arrived,
very often there had been some mistake, and so there was another long
period of uselessness. France had prided herself on her versatility in
airship design. She now had cause to regret it as she viewed the almost
helpless confusion it had caused in her air service. Her machines,
moreover, were much inferior to the German in armament, speed and
climbing gauges, cameras, and all the hundreds of accessories which gave
the German machines their initial advantage. But experience is the best
teacher, and no sooner had she seen wherein she fell short than
dauntless France mustered all her resources to correcting past mistakes.
Order was brought out of confusion, and it was only a very little while
before the German war lords had need to look to their laurels, for the
Frenchmen were far outstripping them in the air.
There was one "accessory" which the airplane of the Hun lacked, and
which all his mechanical skill and ingenuity were not able to provide:
_a pilot with the dash and daring of the French!_ Even in those first
dark days when the French planes were the equals of their adversaries
neither in numbers nor in capabilities,--a continuous stream of gallant
French pilots took to the air and proved that they could surprise and
outmaneuver their slower-thinking opponents. While they held the line in
their inferior craft, French manufacturers were rushing newer and better
equipped machines to reenforce them.
Great Britain was far behindhand in aircraft production when the trumpet
of war sounded,--in fact, her air force was considered a negligible
quantity by friend and foe alike. By dint of persevering search she
managed to scrape up a small group of planes of many makes and for the
most part antiquated. She sent them--along with her "contemptible little
army "--to France, and there they succeeded in holding their own during
the first great German push. When the Stories of heroic fighting against
hopeless odds, of British airmen flinging their lives in challenge
against the foe in the great air struggle, began to reach home, the
British lion repented his tardiness and a program of aircraft
construction on a large scale was instituted without delay.
In carefully standardizing those first airplanes there was one point
which the crafty Germans overlooked: which is, that you can't make a
dray horse run fast, nor a race horse draw heavy burdens. The same thing
holds good with the "steeds" of the air. A plane which is designed for
great speed is never as good a burden bearer as one which is built to
lift heavy weights at the expense of swiftness in flight. As soon as the
duties of the airplane began to be specialized, the airplane itself
began to appear in certain definite types.
Now of course the duties of the airplane in wartime are numberless, but
out of the early confusion _three_ types of machines were finally
evolved, which, with the addition of equipment, such as a camera,
machine guns, etc., are suitable for practically any sort of work over
the land. They are:
1. The high speed fighting machines.
2. The reconnaissance machines.
3. The bombing machines (including the day and the night bombers).
Of all military airplanes there is none so fond of "aliases" as the high
speed fighting machine. Possibly in order to baffle the uninitiated, or
to surround itself with an atmosphere of uncertainty and romance, it
goes by first one title and then another. Most often we hear it called a
_speed scout_, perhaps for the reason that _it does no scouting!_ At
other times it masquerades proudly under the fine French titles of
"Avions de Chasse" or "Avions de Combat." It is referred to as a
"chaser," a "pursuit machine," a "battle plane" and a "combat
machine"--but whatever it is _called_, in type it is the small, fast
airplane, usually a single seater, quick in climbing, agile as an
acrobat, able to "go" high and far,--for its duty is to run every enemy
machine out of the sky and sweep the board clean before the heavier
service machines begin their tasks of the day. It should be able to
reach a height of from 18,000 to 23,000 feet, or in the language of the
air, it must have a high "ceiling." From altitudes so tremendous that
they awe the mere earthly pedestrian it swoops down upon its
unsuspecting victim, opening upon him a stream of machine gun fire. For
its pilot is also a skilled gunner and a crack shot. Upon his ability to
maneuver his machine swiftly and cleverly and hit his target unerringly
depends his own life and the life of a costly military airplane.
The reconnaissance machines and the bombing planes may do valuable
service,--and indeed they invariably do--but it is the "speed scout"
that covers itself with glory. The reason is that its career brings it
nearer to the "personal combat" of the knights of old than anything in
modern warfare. Driving his swift Nieuport scout as a knight would have
ridden his charger, the beloved Guynemer went forth to challenge the
German fighters,--and other Frenchmen and Englishmen and Americans have
followed him. It is a fact beyond all question that this branch of the
service has produced some of the most truly unselfish and heroic figures
of the whole war. The "speed scout" pilot did not need to be a man
deeply versed in military affairs--as for instance the pilot and
observer of the reconnaissance machine must be,--but he did need
dauntless courage, unfailing nerves of steel, dash and daring and
contempt for his own safety. So wherever the "speed scout" has blazed
its trail of fire across the sky, there have sprung up the names of men
whose heroic deeds have made them the idols of the whole world. Usually
they have been very young men--young enough for their ideals to have
kept fresh and untarnished from the sordid things of life, and thus they
have written their names among the immortals.
[Illustration: _Copyright Underwood and Underwood_
A PHOTOGRAPH OF NORTHERN FRANCE TAKEN AT A HEIGHT OF THREE THOUSAND
FEET]
Less appealing to the imagination, perhaps, but no less vital to the
progress of modern warfare, is the slower flying reconnaissance craft.
This machine is always a two-seater, and sometimes a three, for at the
very minimum it must carry a pilot and an observer, while a gunner is a
very convenient third party in case of an attack from enemy scouts. This
type of machine is used for photographic work, for artillery "spotting,"
and for many general service duties over the lines. In the early days of
the war it was customary for the photography airplane to be escorted on
its mission by a group of fighting machines, who hovered about it and
engaged in battle any airplanes of the enemy that might seek to
interrupt its important work. But the last year or so have brought many
improvements in airplane construction and it has been found possible to
build a machine which can not only carry the heavy photographic
apparatus and a couple of machine guns, but which can also travel at a
good speed and climb fast enough to escape from the anti-aircraft guns.
Instead of the rather helpless, clumsy, slow-flying reconnaissance
machines of the early part of the war, we now have powerful "aerial
dreadnaughts," which no longer need to run away, but can stay and fight
it out when they are interrupted in the course of their air duties.
Military photography is one of the most fascinating of the side issues
of the war. Before the day of the airplane it was the scout or spy who
worked his way secretly into the enemy's lines and at great personal
risk,--and often after many thrilling adventures, if the story books are
to be believed--brought back to his commanding officer news of the
disposition of troops, etc., in the opposing camp. To-day the spy's job
has been taken away from him. No longer is it necessary for him to creep
under cover of night past the guard posts of the enemy. A big,
comfortable and efficient airplane flies over the ground by broad
daylight and collects the necessary information a great deal better than
the spy ever could have secured it.
[Illustration: _Copyright Underwood and Underwood_
AN AIRPLANE VIEW OF THE CITY OF RHEIMS, SHOWING THE CATHEDRAL]
A reconnaissance camera has very little in common with a kodak. The
observer does not tilt it over the edge of the machine, focus it on some
interesting object and "snap" his picture. As a matter of fact it works
more after the manner of a gun. It is fixed in the bottom of the
airplane, facing downward. The observer has been instructed before
leaving the ground that a certain area or trench is to be photographed.
Straight to the beginning of that trench line the pilot heads his
machine. The observer compares the country over which he is flying with
the chart or map which he carries. Just as a gunner sights a target, he
locates the beginning of the trench line to be photographed through a
bull's eye, and immediately pushes the button which sets the camera
working. From that point the camera operates automatically, taking a
series of overlapping pictures of the country it looks down upon. With
calm determination the pilot holds his machine to the course laid out,
in spite of any opposition that may arise in his path, for the slightest
deviation from that fixed line of flight will mean a gap in the
reconnaissance report which the pictures represent. But once he has
covered the required area, he turns and flees. In less time than it
takes to tell that magazine of films is being developed in a dark room.
From there the printed pictures are rushed to an expert interpreter who
reads the secret meanings of the things he sees--this or that dark
blotch or peculiar looking speck suggests to his trained mind a machine
gun nest, a railroad center, an observation post, a barbed wire
entanglement, a camouflaged battery, an ammunition dump, or what-not.
Pasted together so that they give a continuous view of the foe's
territory, the printed pictures are hurried to headquarters, where in a
few brief moments their message has been turned into a command to the
troops. By the word that those pictures bring the battle is directed,
and the blow is aimed straight at the enemy's vital spots.
Occasionally instead of a series of photographs of a trench line or
limited area, a continuous set of pictures of a broad space of country
is desired. Then instead of a single machine as described above, a
squadron of reconnaissance machines set forth, flying in V formation,
with the leader of the squadron flying in front at the point of the V.
The moment he reaches the area to be photographed, he notifies the
machines behind him by firing a smoke rocket with a signal pistol. At
that signal the V broadens instantly, so that it becomes almost a
straight line, the commander keeping only slightly ahead so that he may
lead the way. On and on that broad V formation of airplanes sweeps,
every camera registering, and all keeping close enough together to
produce slightly overlapping photographs. Each machine will bring home
a long line of pictures of the country over which it passed, and those
lines, pieced together, will make a large military map of the entire
region. That is if everything goes smoothly, which in war time it seldom
does. More likely that plucky V will be pounced upon by a herd of fast
fighting machines whose duty it is to see that none ever return with
their information to headquarters. There will follow a terrific contest;
the observer in the reconnaissance machine becomes a gunner, and fires
away at his pursuers, while the never-failing camera keeps steadily on
with its job of recording. As nearly as possible the V formation is
held, for much depends upon it, but suddenly a great gap appears in the
line. "Done for" with a direct hit, one brave machine goes crashing
earthward. That will mean a gap in the "map" that is in the making.
Still the V presses on relentlessly. One of the planes begins to lag
behind. There is something wrong with its engine. It does its best to
keep up with its fellows, but soon it is left behind, and the enemy
craft dive after it. Battered and torn, its numbers depleted sadly,
several of its crew wounded, its wings perhaps riddled with bullets, the
photographing squadron turns its face toward home, and, flying now as
high as possible to keep out of sight, puts on all speed for the safe
side of No Man's Land. Military photography _sounds_ easy and
comfortable. It _demands_ the type of courage which can make a man stick
to a given line of flight, even when certain death lies straight ahead.
Sometimes a machine carries both bombs and a camera, and, as it drops
its missiles, keeps a continuous record of its "hits" to carry home. And
that brings us to the bombing machine, last but not least of the trio of
military airplanes.
The bomber that works by day and near to its own lines, is similar to
the reconnaissance machine, except that it does not usually carry a
radio apparatus or a camera. Instead, the greater part of its cargo
consists of bombs, dread instruments of destruction which will fall on
the railroad junctions, troop trains, staff headquarters or ammunition
dumps of the enemy. The day bomber is never used for long distance work,
and so it does not need to be of tremendous size, as the machine which
must carry fuel for an all night run as well as a large quantity of
bombs to drop on a far away important objective.
The night bomber is the giant of the sky. The greatest genius of the
cleverest designers has been expended upon its construction. More and
more its tremendous importance is being recognized. Its activities
precede every great offensive movement, for it flies over the enemy's
country, leaving a trail of terrible destruction in its wake, and
"preparing the soil" for the infantry advance. Deep in the territory of
the foe it searches out the great supply centers and railway terminals
and there it unloads its cargo of bombs.
If the Allies had possessed a sufficient number of these huge bombing
planes they could have carried on an aerial warfare against Germany
which would have defeated her without nearly so great a sacrifice of the
lives of the infantry. The work is dangerous, but a single bombing plane
could have wreaked more vengeance upon the Hun than perhaps a whole
regiment of the bravest fighters. Consequently its use would have meant
economy of human lives.
These fearful shadows that walk by night require pilots of the utmost
skill to navigate the sea of darkness, as well as bomb droppers and
gunners whose training has been perfect. The largest of them are
equipped with either two or three powerful engines, each working a
separate propeller. Such a machine can carry as much as five tons of
explosives, with fuel for a twelve hours' flight.
The night bomber is very often a huge triplane, for the extra wing
surface gives greater lifting power. At the same time the triplane has
greater stability and has a fair chance of reaching home even when one
of its planes has been badly damaged. It is the same with a machine
which has two or more engines: even when one of these has been put out
of order by the shots of the enemy the airplane can still reach home.
The night bombers must travel long distances, carry great cargos, bomb
their objectives and make their escape, and so in the construction of
their machines as much stability, lifting power and speed as possible
has been the aim.
Usually it is some important munition base or factory center that is
supplying the German troops, which the airmen set out to bomb. They
travel in squadrons not only for safety, but because in this way an
almost unlimited number of bombs can be carried and dropped
simultaneously. Often a second squadron follows the first at a short
distance. By the light of the terrible fires that the first set of
explosives dropped are bound to start, this second squadron can drop its
bombs with greater precision directly on important buildings that must
be destroyed.
Moving slowly under their great load of explosives, and flying low,
these two squadrons of destroyers start for some point in the heart of
the German Empire. Like ghosts they "feel their way" mile after mile.
They are not anxious to invite detection, for under the great weight of
their "messages" to Germany, they would not be able to maneuver quickly
or to climb to safety.
Once those tons of explosives have been released and the noise of their
dreadful havoc has aroused the anti-aircraft gunners of the enemy, those
bombing planes will find the earth an uninviting sort of region and they
will be glad to spring into the protecting silence and darkness of the
upper air. And this they can do easily, for, rid of their load, they
possess unusual climbing powers. The second squadron of bombers, flying
over the same territory may expect a warm reception, and they will need
to do their work quickly and beat a hasty retreat.
Such are the mysterious doings of the night. When the early dawn
appears, gray and heavy eyed, it will find the bombing planes tucked
away drowsily in their hangars, scarcely knowing themselves whether the
journey up the Rhine was a reality or merely a terrifying dream.
And with the dawn their daylight sisters will take up the work near
home. Word has just come that enemy reinforcements are moving up to the
front along certain roads. "Fine," sings out a young lieutenant,
appearing unexpectedly on the field from a small, carefully camouflaged
office. "We will make them dance for us this morning!" He talks quickly
and determinedly with a group of pilots, giving instructions, charging
all to keep the formation. Machines are gone over to make sure that
everything is in perfect condition. Then the first bombing plane,
bearing the flight leader, "taxis" across the field, appearing to
stagger under its great burden. Suddenly it takes to the air, and like a
large graceful bird, its clumsiness all gone, it soars up into the blue.
Rapidly the other big birds follow suit, and at a signal they are off,
the flight commander heading the group, and the others following in
close formation, like a huge flock of wild geese.
On and on they fly, until beneath them appears the winding ribbon of
road that is their objective. It is crowded with marching troops, gun
wagons, supplies. As they swoop close to the earth they catch a swift
glimpse of white faces turned up at them with terror. Then panic falls
upon the marching column and, helter-skelter, every man tries to break
away to a point of safety. In another moment guns are turned upon the
bombers, but they dodge the flying shells and let go their heavy
explosives, which crash to earth with dreadful uproar. Where a few
moments before the Huns were following their way undisturbed there is
now a road in which great furrows are plowed; huge holes gape open and a
hopeless mass of débris covers the earth. The columns of the enemy will
be blocked for many hours while the mass is being cleared away.
Satisfied with the results of their exploit the bombing squadron turns
swiftly toward home.
How simple a matter it seems at first glance to release a bomb and hit a
given point below. Actually it requires the very highest skill. To begin
with, the airplane is moving at tremendous speed, and the bombardier (as
the man who drops the bombs is called) has to know exactly how the
forward motion of the airplane will affect the direction that the bomb
takes on its course toward the earth. Moreover the bomb has a speed at
starting equal to the speed of the airplane, and this beginning speed is
increased by the action of gravity drawing it down. It may be aided in
its journey by the wind or retarded, according to the wind's direction,
and this too must be taken into account, if the target is to be hit.
Bomb dropping can only be carried out successfully with the aid of the
most delicate and complicated range-finding mechanism, with which every
bombing plane is equipped. The Germans have led the way in inventions
for this purpose, and their Goertz range finder is perhaps the best in
the world.
The bombs themselves are generally carried in vertical position,
one-above another, in the body of the airplane, and by an automatic
arrangement, as one is released, another slips into place, ready to be
dropped.
Now that we have made the acquaintance of the three types of machines
that are used over the trenches--the "speed scout" or small fighting
machine; the larger armed reconnaissance plane; and largest of all, the
bomber--let us go back and give just a hasty glance at the main points
of their construction.
First we must recall the "A B C facts" we learned about wing
construction. A wing gains lifting power from two sources: the upward
pressure of the air current underneath it, and the force of the vacuum
above it which is created by the arch of the wing. If a wing is only
slightly arched it can move _forward_ through the air more swiftly, but
it will not have the _lifting power_ of the high arched wing. This is
the reason that an airplane which must be a weight carrier cannot be as
fast in flight as the "speed scout," which has only its pilot and a
machine gun to carry.
The "speed scout" is always a small machine, usually a single-seater,
with a gun in front that fires over or through the propeller. In the
early part of the Great War it was most often a monoplane, but the
smaller biplane took its place, because, with practically the same
speed, it combines greater stability.
The planes of the speed scout are very flat as compared with those of
the reconnaissance craft. This airplane must carry machine guns,
photography apparatus, radio, and a pilot, an observer, and often a
gunner. Its wings must therefore be arched to give it lifting power, but
at the same time it becomes a much slower flying machine than its
smaller sister.
Lifting power of a wing can of course be increased _up to a certain
point_ by increasing the wing area, so that a greater air pressure is
created below. Beyond that certain point the machine would become
unwieldy and would lose its balancing properties. Yet this idea has been
put into practise in building the latest types of aerial dreadnaughts
used for reconnaissance. These airplanes have gained their lifting power
partly by increasing the wing spread and partly by arching the wing.
Thus a wing has been secured which offers the minimum resistance to
forward motion through the air, together with the maximum weight
carrying ability. Biplanes of this type are by far the most popular of
those designed for general service, for they combine speed, climbing
ability, and lifting power,--thanks to their strong armament they can
defend themselves or run away quickly as the situation demands.
But there is one other method which has not yet been mentioned of
increasing the lifting power of an airplane. It is simply to add a third
wing. When we have made the wings of the biplane as large as we dare,
and have curved them to make them weight-bearers, if the resulting
machine is still not strong enough to carry as many tons of explosives
as we desire, there is only one thing left to do and that is to add a
third wing. Thus the triplane made its appearance in answer to the call
for planes which could carry vast cargoes of explosives and fuel for
journeys of many hours over the enemy's country. The huge night bombing
machine of the present time is almost always of the triplane type.