Thus when the first division of the Moslem submarine squadron charged at what its commanders thought were the hulls of their enemies, their rams passed harmlessly underneath them, merely striking the magnet and knocking it aside. The moment they had passed the magnet, its attraction swung their needles back, and showed that some mysterious mistake had been committed, but before they had time to turn and seek the mark afresh the Federation ships were upon them, and their rams had rent their way into their sides. In this manner every ship of the first division had been destroyed within three minutes after it had made its first and last charge. Then the Federationists had risen to the surface for an instant to reconnoitre by means of the arrangement of mirrors previously described, and sinking again had worked their way back towards the transports, formed in a huge circle round them, and had sent torpedo after torpedo into their midst. As soon as the flotilla had been thrown into confusion they had converged until they could communicate with each other by means of their submarine signals, and after that they had attacked the enemy singly. Ship after ship charged into the _mêlée_, did her work, and retired, if she escaped destruction, to give place to another. Only twenty Federation ships had been engaged in each of the five battles, and of these forty in all had been destroyed, a loss utterly disproportionate to the gigantic damage that had been done to the enemy. Khalid the Magnificent divined intuitively that the disaster which had overwhelmed the expedition which he had commanded in person was only a portion of a result achieved by some elaborate and consummately-conceived scheme of defence which must have been simultaneously put into operation against his other expeditions. What had succeeded against his own might well have been expected to have succeeded against them. He at once despatched four squadrons of ten air-ships each to Tripoli and Tunis, Algiers and Oran, with orders to collect all attainable information, and to return to Alexandria as soon after sunset as possible. Then he turned the prows of the remainder of his fleet towards his capital, and gave the signal for full speed ahead. CHAPTER XXIV. WAR AT ITS WORST. WITHOUT even pausing to see the effects of his charge upon the three air-ships above Alexandria, Alan kept the _Avenger_ going at full speed, soaring up into the higher regions of the atmosphere with her prow pointed to the north-east. About three hours later she was floating at an elevation of nearly five miles above Moscow, not stationary, but sweeping round and round in vast circles on her quadruple wings after the manner of the condors of the Andes, which thus sustain themselves on almost motionless wings at vast elevations and very small expenditure of force.