I had not been severely wounded, but I felt as if my head was double its normal size, and there was a noise in my ears as of the wheels of an express engine. The other wounded and the soldiers of the ambulance corps said that the Belgians had been pushed back to the fortress; we heard, however, that severe fighting was still going on. Wounded soldiers were being brought in continuously, and they told us that the Germans had already taken in the first assault several fortifications like outer-forts, but that they had not been able to maintain themselves because they had not been sufficiently provided with artillery. The defended places and works inside the forts were still practically completely intact, and so were their garrisons. The forts were not yet ripe for assault, so that the Germans had to retreat with downright enormous losses. The various reports were contradictory, and it was impossible to get a clear idea of what was happening. Meanwhile the artillery had begun to bombard the fortress, and even the German soldiers were terror-stricken at that bombardment. The heaviest artillery was brought into action against the modern forts of concrete. Up to that time no soldier had been aware of the existence of the 42-centimeter mortars. Even when Liège had fallen into German hands we soldiers could not explain to ourselves how it was possible that those enormous fortifications, constructed partly of reinforced concrete of a thickness of one to six meters, could be turned into a heap of rubbish after only a few hours' bombardment. Having been wounded, I could of course not take part in those operations, but my comrades told me later on how the various forts were taken. Guns of all sizes were turned on the forts, but it was the 21- and 42-centimeter mortars that really did the work. From afar one could hear already the approach of the 42-centimeter shell. The shell bored its way through the air with an uncanny, rushing and hissing sound that was like a long shrill whistling filling the whole atmosphere for seconds. Where it struck everything was destroyed within a radius of several hundred yards. Later I have often gazed in wonderment at those hecatombs which the 42-centimeter mortar erected for itself on all its journeys. The enormous air pressure caused by the bursting of its shells made it even difficult for us Germans in the most advanced positions to breathe for several seconds. To complete the infernal row the Zeppelins appeared at night in order to take part in the work of destruction. Suddenly the soldiers would hear above their heads the whirring of the propellers and the noise of the motors, well-known to most Germans. The Zeppelins came nearer and nearer, but not until they were in the immediate neighborhood of the forts were they discovered by our opponents, who immediately brought all available searchlights into play in order to search the sky for the dreaded flying enemies.