The battle of the Somme has an added in terest because it was here tanks were first used against the enemy. This new battle machine was developed by British army experts out of the Holt farm tractor, of Peoria, Ill. It was an armored car whose locomotion .was arranged on the caterpillar principle, which enabled it to cross the roughest ground and demolish the ordinary obstacles of a battlefield. The ma chines were manufactured in England with great secrecy, and when they appeared in action in the attack on Courcelette on 15 September the British soldiers were as much atonished as the Gerrnans. Twenty-four of them were sent forward ahead of the troops, and 17 sur vived the battle. They strudc terror to the hearts of the enemy, who thought that only Germany could invent new machines of war. They were designed as instruments of offense, and although they were useful in that capacity, their greatest service was in demolishing wire entanglements and opening the way for the advance of the infantry. Before the tank ap peared the wire was left to the action of high explosive bombardments, which were not effect iye in less than several hours. By devising a hght and speedy tank the Entente Allies were able to send .it forward with a barrage, clean up the wire in an hour, while the long range guns isolated the opponenes front lines and placed them at the mercy of an infantry charge. In this lcind of service the tank found its great est value. It restored the element of surprise to battle tactics.
3. German Retreat in 1917.— The year 1917 was a period of hard fighting on the western front. Hardly a sector from Verdun to the North Sea but saw severe battle. During 1916 the French had played a waiting game, leaving time for the British army to reach the state of veteran effectiveness. Their one great strug gle, at Verdun, was a defensive battle. The one great attempt of the British, the battle of the Somme, was in reality a massive bit of ad vanced training. In 1917 both armies were at the highest state of efficiency. They kept the enemy on the defensive throughout the year, delivering many small blows and several mighty ones. The reader who is impatient with mere detail may wish to hurry on to the decisive year of 1918, when the great tragedy produced a vast sweeping movement which led to the dramatic close of 11 Novem.ber. But we must remember that 1917 has its place in the general story. Here was put into full operation that process of attrition that lowered the fighting strength and morale of the Teutons, gave con fidence to their opponents, and made possible the victory of 1918.
For Germany 1916 was a bad year. Having brought Russia to a standstill in 1915 she had tried to win a decision in 1916 by forcing France to a separate peace. She failed in that and opened an ineffectual campaign for peace in December of the same year. Perhaps she did not expect it to succeed, but it at least satisfied the growing feeling of the Germans that a fair offer should be made to end the war in a compromise. Her offer was refused but she still hoped that it would eventually be accepted. Let Germany fortify herself on all sides, hold ing to what she had won, and when her enemies had spent themselves in fizrther fruitless assaults they would come to reason and make terms. Russia was no longer a terror; for Brusiloff his last reviving gasp had failed in the campaigns in Volhynia and on the Dniester, despite apparent victories. Ru mania, forced into the war by a treacherous' Russian ministry, had been given such a drub bing that no other Ballcan state was likely to dare German wrath. In keeping with this policy
of impregnable defense Germany decided to draw in her western battle front and establish it in a position which, as she believed, would resist the sternest efforts that could be brought against it This decision implied the belief that her line as it existed in the winter of 1916-17 was not satisfactory, and for that opinion there was a good reason. Before the July offensive of 1916 the line had made a great western bulge between Arras and Soissons, and it .was here that the French and British delivered their blows in the long drawn out battle of the Somme. The result was that the salient was beaten in at the middle, between Albert and Chaulnes, leaving two small salients at the ends of what had been a large flat one. The line, therefore, between Arras and Soissons had in it two undesirable angles. Moreover, at the inner part, where the French and British cut deeply in the battle of the Somme, the line was very soft, being recently constructed, and during the winter the British improved every spell of fine weather to take another bit from the hands of the enemy. It was not of her own volition that Germany decided to shorten her line, but through the realization that the defenses she was holding were not dependable.
To meet the difficulty the so-called Hinden burg line was constructed. Beginning near Arras it ran in a straight line to a point on the Oise five miles southwest of La Fere, and then gained the Aisne near Soissons in a westerly bending curve across the plateau that lies be tween Laon and the mouth of the Aisne, where it united with the old trench system. It was about 70 miles long, which was about 15 miles less than the old line. It was in reality a system of trenches four or five miles wide in well-selected positions, the trenches protected by deep wire entanglements and many redoubts and other points of concentration. The trenches themselves represented all that had been learned in trench construction during the two and a half years of the war. There were many dugouts and concrete chambers well beneath the danger point from high-explosive shells. The Germans believed that it could not be taken. In their own words it was the Siegfried Stellung, al though their opponents persistently called it the °Hindenburg line The section at Arras was expected-to have to sustain severe attacks, and to make assurance stronger a switch line was constructed eight miles east of the town, starting at Drocourt to the northeast of Arras and joining dm Siegfried line at Queant Their preparations made they began to with draw their heavy guns and supphes early in March. It was not until 10 March that the retirement began to be observed by the Allies, who were then pressing forward on Bapaume in their deliberate fashion. Their task became easier from day to day, and on 17 March they ordered a general forward movement on a 45 mile sector. The resistance was weak and the troops pressed forward. Bapaume, ChauInes, Roye and Nesle were occupied with little diffi culty. This process was kept up until the end of the month, the Germans fighting hard ,in rear-guard actions with many machine guns in position. They conducted the retreat ably and with small losses. They surrendered a region containing 600 square miles, 18 miles wide at the widest point— west of Saint Quentin— and five miles wide at its narrowest — just south of Bapaume, where the operations of the British had already eaten far mto the old trenches.