Our divisions put in their fresh reserves; they would admit no word of discouragement. Artillerymen who had been at work for two nights and two days tried to bring their guns close up to the infantry. All the remaining tanks were called into service. With the forced burst of energy which may be mistaken for "second wind," we everywhere made gains. Our right had moved along the Meuse to south of Brieulles, which with the bend of the river westward narrowed our front. On the left we had reached Exermont ravine. On the 29th we tried for Brieulles; for Gesnes; for the ravine; and for the escarpments of the Forest, points which the attack of the third day had developed as the locked doors which we must smash through to give us purchase for another general attack. There was a certain fitfulness in these efforts, as of a fire dying down blown into a spitful flame. In the trough of the Aire we were under the raging artillery fire from the heights on either side; and in the trough of the Meuse from the heights across the river and from the whale-back, which I shall describe in later chapters. In the valleys beyond Montfaucon and the neighboring heights we faced the first slopes of the whale-back, which were the covering positions for the Kriemhilde and Freya Stellungen, new trench systems utilizing all the natural strength of the heights as a main line of defense by an aroused enemy in strong force. Our army might now take counsel of necessity, if not of prudence. In the future we must hack and stab our way. Meanwhile we must have rest for the tired troops, or we must have fresh troops, before another considerable offensive effort. A hundred millions of population at home did not mean that we had unlimited trained man-power to draw on in France. Our divisional reserves were exhausted. Replacements were not arriving in sufficient numbers to fill gaps from casualties and sickness. We were not only fighting from the Meuse to the Argonne and holding the line of our new front at Saint-Mihiel, but we had four excellent fresh divisions just going into attack in British and French offensives, not to mention our divisions in tranquil sectors. If we had had more men for the front, we could not have fed them. If we had made a farther advance, we could not have kept our artillery and transport up with the troops. We needed more motor-trucks, horses, and every kind of equipment for that insatiable maw. If we had had more transport, we should hardly have had room for it. The arterial road facilities over the old trench system were as yet unequal to caring for the number of our troops. The bottle necks could not meet the demands of the bottle. Our appetite for victory had exceeded our digestion.