He and his brother Denis formed a very curious contrast, which is nevertheless not uncommon in Irish families. The British army and navy can boast no finer soldiers or sailors, and the Empire no more devoted servants than those who claim Ireland as the land of their birth, and Denis Castellan was one of these. As the reader may have guessed already, he and Erskine had only been on the _Cormorant_ because it was the policy of the Naval Council to keep two of the ablest men in the service out of sight for a while. Denis, who had a remarkable gift of tongues, was really one of the most skilful naval _attaches_ in service, and what he didn't know about the naval affairs of Europe was hardly worth learning. Erskine had been recognised by the Naval Council which, under Sir John Fisher, had raised the British Navy to a pitch of efficiency that was the envy of every nation in the world, except Japan, as an engineer and inventor of quite extraordinary ability, and while the _Ithuriel_ was building, they had given him the command of the _Cormorant_, chiefly because there was hardly anything to do, and therefore he had ample leisure to do his thinking. On the other hand John Castellan was an unhappily brilliant example of that type of Keltic intellect which is incapable of believing the world-wide truism that the day of small states is passed. He had two articles of political faith. One was an unshakable belief in the possibility of Irish independence, and the other, which naturally followed from the first, was implacable hatred of the Saxon oppressor whose power and wealth had saved Ireland from invasion for centuries. He was utterly unable to grasp the Imperial idea, while his brother was as enthusiastic an Imperialist as ever sailed the seas. Had it not been for this blind hatred, the disaster which had befallen the Reserve Fleet would have been repeated at sea on a much vaster scale; but he allowed his passions to overcome his judgment, and so saved the Channel Fleet. There lay beneath him defenceless the greatest naval port of England, with its docks and dockyards, its barracks and arsenals, its garrisons of soldiers and sailors, and its crowds of workmen. The temptation was too strong for him, and he yielded to it. When the _Prince George_ had gone down he rose into the air, and ran over the Isle of Wight, signalling to the _See Adler_. The signals were answered, and the two airships met about two miles south-west of the Needles, and Castellan informed Captain Frenkel of his intention to destroy Portsmouth and Gosport. The German demurred strongly. He had no personal hatred to satisfy, and he suggested that it would be much better to go out to sea and discover the whereabouts of the Channel Fleet; but Castellan was Commander-in-Chief of the Aerial Squadrons of the Allies, and so his word was law, and within the next two hours one of the greatest crimes in the history of civilised warfare was committed.