On the evening of the fifth day after Miss Chrysie had pulled the lever over in No. 1 engine-room a series of unaccountable accidents happened in the engine-rooms of the French Northern Squadron, which was blockading the mouth of the Elbe. Do what they would, the engineers could not keep the engines working smoothly. Little accidents kept on happening with such frequency that the efforts of the whole staff could scarcely keep the engines in working order; and about the same time the officers on the bridges, noticed that the compasses were beginning to behave in a most extraordinary fashion. Even when the ships were quite stationary, they wavered two or three degrees on either side of north, and as the night wore on the variation increased. The next morning there happened what, up to then, was the strangest incident in warfare. The _Charles Martel_, one of the most powerful ironclads in the French fleet, was cruising under easy steam, just out of range of the heavy guns on the canal forts, when the admiral commanding the squadron, who was on the bridge, heard a muffled grinding noise, and felt a shudder run through the vast fabric. The next moment an officer came up from the lower deck, saluted, and gasped: "Admiral, the port shaft has broken, and we are only going quarter speed!" He had hardly got the last words out of his mouth before there was another grinding shock, and a dull rattle away down in the vitals of the ship. "Ah, there is something more!" cried the officer. "They tell me that the engines have been mad all night." "Go and see what it is," said the admiral; "we must put out to sea with one engine." At that moment the chief engineer came up, looking white and scared, and said, in a low, shaking voice: "Monsieur, the crank shaft of the starboard engine has splintered as though it had been made of glass. We are disabled!" "Nom de Dieu!" exclaimed the admiral. "What is that you say?--disabled? and the tide setting in. Then we are lost. A few minutes will take us within range of the guns on the Canal and at Cuxhaven, and in an hour we may be ashore. There is no hope of repairs, I suppose?" "Impossible, Monsieur l'Amiral. It would take weeks in the best dockyard in France to repair the damage." "Then," said the admiral, turning to the commander, who was standing beside him, "we must do what we can. We will not be lost for nothing. Let everything be ready to return the fire of the forts as soon as we are within range."