At one point, below Fossoy, the Germans not only went back to the river, but actually crossed it in the face of the 110th Infantry's advance. Reaching the banks of the river, however, the enemy was within the protection of his big guns, which immediately laid down such fire that it was utterly impossible for the Americans and French to remain. Having had a real taste of triumph, the Pennsylvanians were loath to let go, but fell back slowly, unpressed by the Germans, to their former positions. It was on this forward surge back to the Marne that Pennsylvania's soldiers began to get real first-hand evidence of Hun methods of fighting--the kind of thing that turned three-fourths of the world into active enemies of them and their ways, and sickened the very souls of all who learned what creatures in the image of man can do. They came on machine gun nests, in the advance between Mezy, Moulins and Courtemont-Varennes, to find their comrades who had been taken prisoner in the earlier fighting tied out in front in such a way as to fall first victims to their friends' fire should an attack be made on the gunners. Men told, with tears rolling down their cheeks, how these brave lads, seeing the advancing Americans, shouted to them: "Shoot! Shoot! Don't stop for us!" They saw eight airplanes, painted with the French colors, swoop over the lines, soar low near a barn where a battery had been planted and drop tons of bombs, shaking the earth and demolishing everything about as if an earthquake had occurred. Fortunately in this instance, the battery had been moved to another location, but the same planes poured streams of machine gun bullets into the ranks of our men until driven off by machine gun and anti-aircraft fire. Not the least of the difficulties of our men was the fact that the Germans mingled a certain quantity of gas shells with their high explosives and shrapnel. Ordinarily, soldiers learn to distinguish gas shells from others by the difference in the sound of the explosion, but in such a bombardment as this the sounds are so commingled that even that protection is denied. Therefore, it was necessary for the men to wear their gas masks almost continuously. While these are a protection against the poisonous fumes, they are far from being pleasant. Not only is it more difficult to see and breathe, but what air is inhaled is impregnated with chemicals used to neutralize the gas. Yet for hours at a time, the men had to go through the inferno of fighting under the handicap of the masks.