Page 3585

3585 THE TWENTIETH CENTURY-THE GREAT WAR.

greeted by thousands of rifle bullets; if

further off, by bursting shells from anti-aircraft guns especially designed for that purpose. Enemy aircraft, too, were likely to

endeavor to destroy or drive away the spy.

The exigencies of real warfare quickly

revealed needs in the air not unlike those

upon the water. Some aircraft were built

purely for observation purposes. These

corresponded to the scout cruisers of the

watery main. Others were built primarily

for fighting purposes and corresponded to

battleships. Still others were designed to

carry heavy loads of bombs. Incredible as

it would have seemed fifteen years before,

some types of aeroplanes were actually

armored, to protect both the crew and

also the more vital parts of the machines.

Offensive weapons were at first confined to

automatic pistols and rifles; then machine

guns were installed; and finally some of the

battle planes carried small cannon.

On the sea both sides made considerable

use of hydro-aeroplanes for scouting purposes, and the Allies found these machines

helpful in locating and destroying submarines.

A few instances were reported in which

dirigibles or aeroplanes were able to damage

or destroy merchant vessels or small

warships, but not a single instance occurred

of a battleship being sunk by such an

attack. Certain peculiar properties of

high explosives, in fact, unfit them for

destroying vessels in this manner. The

force of a high explosive, when merely

placed or dropped upon an object is mostly

exerted upward, and only a bomb of

enormous size would be likely to sink a

battleship unless, by rare chance, it should

happen to fall down a smokestack. Furthermore, many of the battleships were

provided with nets designed to intercept

bombs dropped from the air.