The Hindenburg line was really only one of a series of twenty lines, each connected with the others by communicating trenches. The main lines were solid concrete, separated by an unending vista of wire entanglements. At points this barrier barbed wire extended in solid formation for ten miles. This tremendous system of defenses was originally called by the Germans the Siegfried line, and in the spring of 1917 they found it wise, at points where a strong offensive was expected, to fall back to it for protection. It had been their hope that it would prove an impassable barrier to the Allied troops, but now it had been broken, and the moral effect of the British success was even greater than the material.
One of the most noticeable results of the British advance had been the capture of Lens. It had been captured without a fight, because of the British threat upon its rear, but its capture was of tremendous importance. Lens had been the scene of bitter fighting in the latter part of August, 1917, when the Canadians had specially distinguished themselves. This city had been heavily fortified by the Germans who had recognized its importance as being the center of the great Lens coal fields, and they had never given it up. It had sometimes been described as the strongest single position that had ever confronted the Allies on the western front. It had been made a sort of citadel of reinforced concrete. Even the courage and power of the Canadians had only given them possession of some of its suburbs. Between these suburbs and the concrete citadel were the coal pits, with their fathomless depths of ages and the mysteries of kultural strategy. The struggle became a succession of avalanches of gas, burning oil, rifle and machine-gun fire. Both sides lost terrifically, but the Germans had held the town. Now it was given up without a blow and its great coal fields were once more in possession of the French. Before retreating the Germans showed their usual destructive energy and the mines were found flooded as a result of consistent and scientific use of dynamite.
The recapture of Lens was cheering news in Paris. Not the least of the many sufferings of the French during the last two years of the war was that which came from the scarcity of coal. Indeed, more than once during those two winters coal could not be obtained at any price. These periods unfortunately came in the latter part of the winter, and it happened they were unusual periods of intense cold. Thousands of people stayed in bed all day in order to keep warm. The capture of Lens, therefore, had been anxiously desired. Nearly the whole of the French coal supply had come from Lens and the adjacent Bethune coal fields. The Bethune field, although steadily working, had never produced enough coal for even the pressing necessities of the French munition works.
The news that Bapaume had fallen on August 29th brought back, especially to the British, memories not only of the previous year and of the great forward movement which, on March 17th, had swept them over Bapaume and Peronne, but also bitter memories of the retreat in the previous March, which had carried them back under the overwhelming German pressure. The capture therefore was balm to their spirits, and an English correspondent, Mr. Philip Gibbs, who had accompanied the British on their previous advance, found officers and men full of laughter and full of memories.
On all sides were the battle-fields of 1916 and 1917; Mametz Wood, Belleville Wood, Usna Hill, Ginchy, Morval, Guillemont. The fields were covered with battle debris, and yet to the English it was sacred ground from the graves of the men who fell there. Those graves still remained. The British shell fire had not touched them, but as the English advanced there were many bodies of gray-clad men on the roads and fields, and dead horses, and a litter of barbed wire, and deep shelters dug under banks, and shell craters, and helmets, gas masks, and rifles thrown here and there by the enemy as they fled. Now it was the Germans that were fleeing, and fleeing hopelessly, sullen, bitter at their officers, impatient of discipline.
One of the great differences between the attacks of the Allies in their last year of the war and those of preceding years, was the increased use and the improved character of the tanks. The tanks were a development of the war. Before the war, however, the development of the caterpillar tractor had suggested to a few farsighted people the possibility of evolving from this invention a machine capable of offensive use over rough country in close warfare. Experiments were made in behalf of the English War Office for some time without practical results.
At last, after these experiments had resulted in various failures, a type of tractor was finally designed which produced satisfactory results. It was a caterpillar tractor, with an endless self-laid track, over which internal driving wheels could be propelled by the engines. It was not until July, 1916, that the first consignment of these new engines of warfare arrived at the secret maneuver ground.
There were two kinds. One called the male was armed with two Hotchkiss quick-fire guns, as well as with an armament of machine guns. The other type, called the female, was armed only with machine guns. The male tank was designed for dealing with the concrete emplacements for the German machine guns. The other was more suitable for dealing with machine-gun personnel and riflemen. Some time was taken in training men to use these tanks, for the crew of a tank must suffer a great deal of hardship on account of the noise of the engine every command had to be made by signs, and the motion of the tank being like that of a ship on a heavy sea, was likely to produce seasickness.
The tanks were painted with weird colors for the purpose of concealment, and when they first appeared caused a great deal of wonder and amusement. They were first used in battle on September 15, 1916, in a continuation of the battle of the Somme, and proved a great surprise to the Germans. The Germans directed all available rifle and machine-gun fire upon them without success. A correspondent narrates that: "As the 'Creme de Menthe' moved on its way, the bullets fell from its sides harmlessly. It advanced upon a broken wall, leaned up against it heavily, until it fell with a crash of bricks, and then rose on to the bricks and passed over them and walked straight into the midst of factory ruins." They were an immense success and had come to stay.