As he was going off duty at midnight, he saw a squat colossal monster come lumbering up through the dusk. A huge rotating belt on either side dragged the Juggernaut car forward, while two wheels behind served for steering. Two protected windows in the front gave place for machine guns of the heavier patterns, and sponsons on either side mounted three machine guns operating through small openings. There were thus eight machine guns to each tank. When it is remembered that the fire of a protected machine gun is equal to fifty men, each tank represented an invulnerable company of 400 men. Moreover, not a shot need be wasted. In full fire, a tank could eject 4,800 shots per minute, or 80 bullets per second, and could carry its own fuel and ammunition. Against the British-invented tanks all the light German trench artillery was powerless. The tank-pilots and gunners wore gas masks, hence gas could not stop them. Rifle bullets glanced from the armor-plate of the tank like hail striking on a window pane. Machine guns peppered its steel skin with no more effect than if the bullets had been pointed peas. Liquid fire found no entrance, even if a projector could be brought near. Nothing could damage a tank save a high explosive shell from the heavy batteries in the rear, and no artillerist in the world could hope to strike a small moving object several miles away. Early next morning the two tanks advanced. There was no road. They needed none. With a grotesque, crawling gait, they waddled down and up shell holes, lurched over trenches and belly-crawled ahead. There was nothing they resembled so much as huge antediluvian tortoises which passed unscathed amid the most ferocious prehistoric beasts, secure in the massive protection of their shelly backs. A hurricane of shot greeted them, till their outlines were dimmed to view in the blue of flying steel. Not a bullet penetrated. Slowly, cumbrously, uncouthly, careening nose down, into a hole, climbing askew nose upwards, they sidled menacingly a tortuous course to the German lines. Wire! Much the tanks cared for wire! They waddled on regardlessly, heeding the barbed trap no more than as though pieces of pack-thread had been stretched along the ground. Such of the wire as was tight enough they snapped, the rest they stamped deep into the mud. Down and up! The tanks straddled the German first-line trench. So far, they had been voiceless. There had not been sign nor sound of human leading. They were the incarnation in metal of grotesque terror. They seemed as an evil dream of machines that had developed life: inhuman, monstrous, dire. Then they spoke. The German trenches on either side were swept clean of men by that concentrated tornado spout of slaughter. The French infantry yelled with delight and plunged into the fray after the tanks. One of the giants lifted an eyelid, as a forward window opened to let through a torrent of machine-gun fire. The blast scorched and ravaged the ground before it.