line, and compel the Germans to evacuate its tip. He was going to push at the base of the triangle on both sides, and, by bending in the lines until his forces met, he would either compel the Germans to run in a hurry and evacuate the strongest part of the district without fighting or he would capture them.

There were four hours of artillery preparation, terrific and intensive, intended to drive the Germans underground and destroy whatever could be destroyed on the surface. Then at five A.M. on September 12, the Americans, assisted by one French corps, advanced. They were preceded by a number of tanks, which could not, however, climb the mountains and were not so useful to them as in some other battles. But, aided by groups of wire cutters, they went through the lines of the German defenses very much as at Cantigny. To their own amazement, they carried everything with a rush and found themselves through the first zone of the German defenses with very small losses and in record-breaking time. The first push had been on the south side of the salient and the second had been on the northern; both had succeeded.

The American army and the world at large were electrified to learn on the following day that the American forces had met and that the salient had been wiped out. Between one hundred fifty and two hundred square miles of territory had been taken from the Germans and many villages had been released from German domination which had been in their hands from the very beginning of the war. Sixteen thousand prisoners, four hundred and fortythree guns, great amounts of material, ammunition, clothes, and food were captured.

The speed of the Americans had been so great that considerable numbers of Germans had been unable to escape from the apex of the triangle. Eventually a good many thousands surrendered.

Whole regiments walked out with their officers. In one case the commander, after surrendering, requested that the roll be called in order that he might discover how heavy his losses had been. The whole regiment answered present except one officer and one private, and the commander then suggested that he should march his own command wherever it was wanted. The Americans advancing to the front met the astonishing spectacle of an entire German regiment, marching off the battlefield under its own officers, and guarded only by a half dozen American cavalrymen, lounging in their saddles after the fashion of American cowboys driving a herd of cattle.

The Americans had proved their quality. They had achieved what the French had been most anxious to do for four years. They had relieved Verdun of all apprehension and had ironed out one of the most important creases in the German lines. They had put Metz within reach of the heavy artillery and were able to shell the most important railroad the Germans had. General Pershing had every reason to be content.

The triumphal entry into St. Mihiel was characteristic of the Americans and French. The American secretary of war, Mr. Baker, with Generals Pershing and Pétain, went quietly to the famous little town and walked through its streets, all but unaccompanied, and without ceremony or signs of triumph. But the identity of the distinguished visitors was soon known to the inhabitants. They poured out to receive them, crowded around them, kissing Mr. Baker's hand, weeping. The sudden relief from the galling oppression which they had endured almost unnerved them.

CHAPTER XLV

THE FINAL PROBLEM

THE problem which Foch had now to meet was extraordinary and difficult. He must carry a defensive system devised by the Germans to prevent the success of any possible assault and which represented the preparations of four years. The German High Command believed that at all costs they must retain the territory of France until peace had been signed. When they came to the peace table they must still hold in their hands northern France and Belgium. Such elaborate defenses must therefore be constructed that it would be impossible to carry them. The British and French for this very reason deemed it essential not to end the war until the Germans had been driven from this very territory, and if possible from the whole country west of the Rhine. Otherwise they must redeem northern France and Belgium at the expense of concessions in Lorraine, in Poland, in the Balkans, or in Italy, which they could not well afford to make. The war also must end in such a way that enough territory could be taken from the Germans to prevent them from ever again making an aggressive assault upon France and Belgium. Foch must therefore win the war in a particular way and in a particular place, and he must overcome the obstacles which the Germans had created during four years to prevent his achieving exactly that end.

On the map are shown the four practically parallel lines of trench defenses which the Germans had constructed between the French border and the battle line. The two anchors of this long line,

which stretched from the mountains to the sea something over six hundred miles long, were Metz, where all four of the lines ended, and Lille to the north, where three of them terminated.

THE FOUR GERMAN DEFENSE LINES AND FIRST OPERATIONS OF FOCH

From a sketch by the Author

The loss of Metz would break all four lines, but the Germans regarded that as unthinkable. The loss of Lille would probably destroy the first and second lines, but not the third and fourth,

which were devised expressly to meet the emergency of its loss. The whole system was also constructed so as to provide against disaster by an Allied success in any particular sector.

The crosses on the map connecting these various trench lines represent what were called switch lines. They were intended to divide the territory into compartments or rooms like the watertight compartments in a ship. The loss of any one, or perhaps two, of them would not sink the ship. The others would keep it afloat. These switch lines, therefore, were to limit the success of the Allies; when they should carry some portion of the first trench lines, they would still find the Germans prepared to fight them and hold the remaining sections of the first lines.

The first line, called the Hindenburg Line, was strongest of all and was really a zone twelve miles broad at most places and comprised of many trench lines, one behind the other, connected by switch lines of various sorts on just the same principles as the larger system. Elaborate barbed wire entanglements had been created in front of all the trenches. Deep pits had been dug, covered by planks and sod so as to look like solid ground, into which it was hoped tanks would fall. Mines and bombs had been planted which could be exploded as the Allied troops passed. The trenches themselves were of concrete and were believed to be too heavy for the Allied artillery to destroy by any length of "preparation.'

Underground at various points were complete houses for hundreds of troops, with dormitories fitted with beds, kitchens, dining rooms, rest rooms, the whole lighted by electricity. In some of these underground houses at least the electric power was provided in characteristic German manner, by a treadmill worked by man power! They compelled prisoners to tramp round on the treadles for hours at a time so that the officers might have light and heat!

The officers' quarters along the Hindenburg Line were under