So complete was the British domination of the air along the front of attack that not a single one of the British artillery observing aeroplanes was lost during the week that the intense bombardment was going on. During the battle British aeroplanes also attacked and silenced a number of enemy machine-gun positions.
The growth of the aeroplane industry has developed as many makes of machines as there are makes of automobiles, but in a general way aeroplanes are divided into four classes—monoplanes, biplanes, triplanes and hydroplanes. About 90 per cent of all designs are monoplanes and biplanes, and the types are distinguished by their single set of wings or planes or the double planes or wings. Both types have their advantages in use, the biplane being regarded as more stable for certain scouting purposes than the monoplane. It can carry heavier weights—has greater lifting power—but is not capable of as great speed or as easily maneuvered.
MACHINE ON PRACTICAL BASIS.
The War has placed the machine on an intensely practical basis. The manufacturers have learned that machines constructed along certain lines will travel at such and such a speed and have a certain lifting capacity, will rise under a particular speed and may be expected to do certain things under certain circumstances, but with all the advance which has been made in the construction of the air machines, the designers do not yet understand all the "factors" that enter into the "why" of the case.
The makers have, however, succeeded in standardizing their machines to a degree. The story of how the aeroplane flies is a highly technical and scientific one, but the basic principle is the reaction of air and an inclined surface in motion. It might be likened to a stone skipping across the surface of a pond, if the imagination can conceive of the water as being air. It is simplicity itself to drive an inclined plane against the air with such force that the impact will produce a lifting power. In raising an ordinary kite, for instance, the boy runs into the teeth of the wind. His kite is so attached to a string as to stand at an angle, and as he runs the pressure against the air drives the kite upward. In the aeroplane the propellers drive the machine into the air with such force that the planes, standing at an angle, guide the machine upward.
There are innumerable problems to be solved—those of buoyancy, delicacy of balance and many others—but the designers themselves have not been able to determine upon a precise formula for their solution. It is sufficient that the aeroplane has reached a degree of practicability in construction and use which insures its permanent existence, and has given the military and the naval forces one of the greatest agencies in the world for protecting themselves and watching their enemies.
CHAPTER X.
WAR'S STRANGE DEVICES.
Chemistry a Demon of Destruction—Poison Gas Bombs—Gas Masks—Hand Grenades—Mortars—"Tanks"—Feudal "Battering Rams"—Steel Helmets—Strange Bullets—Motor Plows—Real Dogs of War.