[Illustration: Map: The North Sea and surrounding countries—Norway,
Denmark, Great Britain, France, Belgium, Holland, Germany.]
FORTS, FLYING AND NAVAL BASES ON THE NORTH SEA
This was not the first time in history that intrenched armies opposed each other. The Civil War in this country set the fashion in that respect. The contending sides in the Great War, however, improved vastly upon the American example. Communicating trenches were constructed, leading back to the company kitchens, and finally to the open road leading back to the rest billets of the armies.
When night raiding commenced, it was speedily seen that straight trenches exposed whole companies of men to enfilading fire. Thereupon bastions were made and new defenses presented by zig-zagging the front-line trenches and the communicating ditches as well.
To the formidable obstacles presented by the trenches, equipped as they were with sand-bag parapets and firing steps, were added barbed-wire entanglements and pitfalls of various sorts. The greatest improvement was made by the Germans, and they added "pill boxes." These were really miniature fortresses of concrete and armor plate with a dome-shaped roof and loopholes for machine gunners. Only a direct hit by a projectile from a big gun served to demolish a "pill box." The Allies learned after many costly experiments that the best method to overcome these obstacles was to pass over and beyond them, leaving them isolated in Allied territory, where they were captured at the leisure of the attackers.
Trench warfare brings with it new instruments. There are the flame projectors, which throw fire to a distance of approximately a hundred feet. The Germans were the first to use these, but they were excelled in this respect by the inventive genius of the nations opposing them.
The use of poison gas, the word being used in its broad sense, is now general. It was first used by the Germans, but as in the case of flame throwers, the Allies soon gained the ascendency.
[Illustration: Four photographs of tanks.]
TYPES OF LAND BATTLESHIPS DEVELOPED BY ALLIES AND GERMANS
British light tank, of 1918, with turret action and high speed
British Tank of earliest type, as used at Cambrai.
German land battleship in 1918 on the Western front
Improved French Tank first used in Champagne in 1916.
[Illustration: Painting]
CHARGING ON GERMAN TRENCHES IN GAS MASKS
Each British soldier carried two gas-proof helmets. At the first alarm
of gas the helmet was instantly adjusted, for to breathe even a whiff
of the yellow cloud meant death or serious injury. This picture shows
the earlier type before the respirator mask was devised to keep up
with Germany's development of gas warfare.
The first use of asphyxiating gas was by the Germans during the first battle of Ypres. There the deadly compound was mixed in huge reservoirs back of the German lines. From these extended a system of pipes with vents pointed toward the British and Canadian lines. Waiting until air currents were moving steadily westward, the Germans opened the stop-cocks shortly after midnight and the poisonous fumes swept slowly, relentlessly forward in a greenish cloud that moved close to the earth. The result of that fiendish and cowardly act was that thousands of men died in horrible agony without a chance for their lives.
Besides that first asphyxiating gas, there soon developed others even more deadly. The base of most of these was chlorine. Then came the lachrymatory or "tear-compelling" gases, calculated to produce temporary or permanent blindness. Another German "triumph" was mustard gas. This is spread in gas shells, as are all the modern gases. The Germans abandoned the cumbersome gas-distributing system after the invention of the gas shell. These make a peculiar gobbling sound as they rush overhead. They explode with a very slight noise and scatter their contents broadcast. The liquids carried by them are usually of the sort that decompose rapidly when exposed to the air and give off the acrid gases dreaded by the soldiers. They are directed against the artillery as well as against intrenched troops. Every command, no matter how small, has its warning signal in the shape of a gong or a siren warning of approaching gas.