That was what mystified the Parisians. Falling out of a clear sky, the missiles fell, bursting in the streets. Aeroplane bombs, was the first thought, for Paris was used to aerial raids. But these were undeniably shells, not bombs, and there were no aeroplanes in sight. And they continued to fall with painful regularity. Arriving at 15-minute intervals, it was found that at least 21 shells had fallen that day. They were not huge, weighing about 260 pounds, but they were large enough to do considerable destruction, and to kill people in streets, squares, and markets. For a week they kept falling, and then occurred a tragedy that shocked not only Paris but the whole Christian world. It was Good Friday, and the cathedrals and churches were crowded with worshipers. As the congregation--women and children, and men too old to fight--prayed in the Church of St. Gervais, a shell crashed through the roof of the building, and exploded. Seventy-five persons were killed, of whom 54 were women--and five of these were Americans. Ninety others were injured. In all Christian lands people were aghast at this slaughter of the defenseless. Indignation was stirred all the more by the knowledge that this bombardment was wholly without military value. Its entire object was to terrorize the civilian population. It was only another example of German frightfulness. After long search by aircraft it was discovered that shells were coming from the forest of Gobain, near Laon, nearly 75 miles from Paris. There, inside the German lines, was located this new instrument of warfare, the latest surprise sprung by the Germans and one of the most sensational of the whole war. Worst of all, the Allies had no effective reply. Aeroplane bombing proved ineffective, and the Allies had no guns which could reach it. For five months Paris endured this menace. No one knew where the shells would fall next, or who would be the victim. The city, however, went about its business and kept up its courage. But here in America there was being prepared the Nemesis of the Teuton terror. The United States Navy was at that very time building long-range guns that, while not capable of firing such great distances as the German cannon, were far more powerful and effective in action. Germany's gun was a freak, merely able to hurl comparatively small shells seventy miles or more. Huge projectiles weighing 1,400 pounds were fired by our guns, and wherever they hit, everything in the vicinity was smashed. Elaborate emplacements were required for the German gun, taking considerable time to construct. Their cannon could be fired from only one point. The American guns were on railway mounts, and could be rapidly moved from place to place, wherever they were needed. Only a few hours were required to get them into position. In fact, if necessary, they could fire from the rails.