It was while they were in this trench that Pen had his "baptism of fire." Late one afternoon the German artillery began shelling fiercely the first line of Allied trenches. Aleck and Pen were both on sentry duty. Just beyond them Lieutenant Davis stood at an advanced lookout post intent on studying the outside situation by means of his periscope. At irregular intervals machine guns, deftly hidden from the sight of the enemy, poked their menacing mouths toward the Boche lines. Now and then, finding its mark at some point in the course of the winding trench, an enemy shell would explode throwing clouds of dust and debris into the air, wrecking the earthworks where it fell, taking its toll of human lives and limbs. Twice Pen was thrown off his feet by the shock of near-by explosions, but he escaped injury, as did also Aleck. It was apparent that the Germans were either making a feint for the purpose of attacking at some unexpected point, or else that they were preparing for a charge on the trenches which they were bombarding. It developed that the latter theory was the correct one, for, after a while, they directed their fire to the rear of the first line trenches, and set up a still more furious bombardment. This, as every one knew, was for the purpose of preventing the British from bringing up reinforcements, and to give their own troops the opportunity to charge into the Allied front. The charge was not long delayed. A gray wave poured over the parapet of the German first line trench, rolled through the prepared openings in their own barbed-wire entanglements, and advanced, alternately running and creeping, toward the Allied line. But when the Germans were once in the open a terrible thing happened to them. The machine guns from all along the British trenches met them with a rain of bullets that mowed them down as grain falls to the blades of the farmer's reaper. The rifles of the men in khaki, resting on the benches of the parapet, spit constant and deadly fire at them. The artillery to the rear, in constant telephone touch with the first line, quickly found the range and dropped shells into the charging mass with terrible effect. A second body of gray-clad soldiers with fixed bayonets swarmed out of the German trenches and came to the help of their hard-beset comrades, and met a similar fate. Then a third platoon came on, and a fourth. The resources of the enemy in men seemed endless, their persistence remarkable, their recklessness in the face of sure death almost unbelievable. The noise was terrific; the constant rattle of the machine guns, the spitting of rifles, the booming of the artillery, the whining and crashing of shells, the yells of the charging troops, the shrieks of the wounded. In the British trenches the men were assembled, ready to pour out at the whistle and repel the assault on open ground; but it was not necessary for them to do so. The German ranks, unable to withstand the