since the British endeavors of the spring and summer had well-nigh exhausted British resources for the time being. But an overwhelming disaster had befallen the Italian army and it was necessary to exert pressure on another battle-front to relieve as far as possible the grave strain upon the Italian army along the Piave. Moreover, with Germany pouring troops from the eastern to the western front, it was well to strike before Germany could completely consolidate her new strength. Finally, the British production of tanks had placed hundreds of these fighting machines at Haig's disposal. They had been used in previous battles, but with little effect, because they had advanced over ground not conducive to their best services and also because they had not been used in sufficient numbers. Haig believed that by throwing hundreds of tanks against the German lines in a surprise attack, he could achieve a notable gain.

In most of the great battles preceding the Battle of Cambrai, the attackers had prefaced their advance by a heavy artillery bombardment. It had been discovered that if the bombardment were sufficiently heavy, gains would inevitably follow; but the weakness of that method consisted in the warning it gave to the enemy of the location of the effort. Haig had determined to use his tanks with no preliminary bombardment, trusting to surprise. He chose for his attempt the sector opposite Cambrai, some eight miles within the German lines, largely because the nature of the ground in that region would make the tank attack highly effective.

On November 20, hundreds of tanks, which had been skilfully assembled in secret behind the British lines, suddenly rolled toward the German lines, at the same moment that a heavy artillery barrage fell behind the first enemy positions. The tanks had little difficulty in breaking through the barbed wire entanglements, in clearing out the machine-gun nests and in mowing down the defenders of the trenches. The tanks did most of the work for the infantry which followed closely upon their heels, and within a few hours all three German lines had been captured on an eight mile front. For the first time in many months, the Germans were driven completely out of prepared positions and for some hours the fighting was in the open, with the British cavalry taking a large share in the conflict. Havrincourt, Graincourt,

Anneux, Flesquières Ridge, Ribecourt, Lateau Wood, Marcoing, Masnières were taken, and many prisoners fell into the hands of Sir Julian Byng, the commander of the British forces at Cambrai.

But the advance had been uneven and the Germans were rushing up reinforcements. On November 21, accordingly, the British made heroic attempts to straighten out their new lines, and were successful. Advance after advance was achieved, and strategic point after strategic point was captured, until by the evening of November 21, after two days of fighting, the British had acquired a block of territory, almost exactly in the form of a rectangle, eight miles long and five miles wide. Byng was within three miles of Cambrai and proceeded to bombard the town until it was but a mass of ruins.

On the next day, the Germans recovered sufficiently to launch counter-attacks and the British were strictly on the defensive, at several points being compelled to yield ground to the persistent enemy. On November 23, the British drove for Bourlon Wood and the village of Bourlon, positions which they needed to consolidate their gains and which they had not yet been able to occupy. Until November 27, the battle raged for these positions, which were taken and re-taken by both British and Germans, until finally the British were able to obtain a precarious foothold upon them.

But the British had not managed to lengthen their flanks and the rectangular shape of their own line before Cambrai was an element of great weakness. For Ludendorff, who had become the virtual dictator of Germany's military program, had no intention of permitting the British to hold gains so extensive as those gained by Byng. He rushed up many new divisions and by the end of the month Germany herself was prepared to assault in force. On November 30, the German infantry sprang in great numbers for the British lines. As the Hindenburg Line had been broken by the British through a surprise attack, Ludendorff in turn was using a surprise attack to restore it. Only a cloud of gas gave warning of the German attack on November 30, and the German soldiers reached the British lines with little difficulty under cover of mist and gas. The struggle thus became a hand-to-hand test of strength and in that test the Germans. were victorious. The Germans had made for the sides of the rectangle,

and when they gained along these flanks, the entire British line was in danger of being turned. The Germans were pressing on, wiping out or driving back all detachments opposing them, and gaining most of the important positions. On December 1, 2 and 3, the British, aided by some companies of American engineers, succeeded in stopping the German advance in a number of places for a sufficient length of time to permit the withdrawal of forces in dangerously advanced positions; but the Germans were still coming on, especially on the British right and a further retirement was necessary in order to strengthen the British line. Bourlon and Bourlon Wood were evacuated, and Byng withdrew all along the line until his position had been straightened out into an arc instead of a rectangle projecting into the German trenches. The Germans had recaptured about three-fourths of the ground which they had lost and the net British gains from the Battle of Cambrai amounted to two miles in depth along the four mile front in the centre of what had been the line of advance.