lieutenant, still ignorant of what had happened, made up his mind to go back to see what the English ship was about, and, ordering his helm to be put hard over, rang down to his engine-room for "full speed ahead". Then the furious racing of his engines, as steam was admitted into the cylinders, revealed the ghastly truth that he had lost his propeller and was absolutely helpless, with the nearest land fully forty miles away. He rushed from the bridge down into the tiny engine-room, to consult with and explosively reprimand the engineers for permitting such a mishap to occur; and at length, when his vexation had worked itself off, returned to the deck and gave orders for signals of distress to be made, by means of rockets, to the English yacht. But by that time the _Thetis_ had vanished in the darkness; nor did she re-appear, although the unfortunate lieutenant expended his entire stock of rockets in a vain attempt to attract her attention. CHAPTER FIVE. HIS SPANISH MAJESTY'S GUNBOAT TIBURON. Meanwhile the saloon party on board the _Thetis_, having comfortably bestowed themselves in capacious basket chairs under the awning on the top of the deck-house when the yacht got under way, watched with mingled interest and amusement the strenuous pursuit of their own vessel by the Spanish torpedo boat; and when at length Milsom gave the order for the yacht's engines to be first stopped and then sent astern, they with one accord rose to their feet and brought their glasses to bear upon the torpedo boat, intent upon seeing what would next happen. For although darkness had by this time fallen, the night was beautifully fine and clear, and the mellow lustre of the innumerable stars shed a soft light upon the scene that enabled the watchers, with the aid of their powerful night glasses, to perceive with very tolerable distinctness whatever might happen within so short a distance as a quarter of a mile, or even twice as far. Presently Jack spoke. "She has stopped, I think," he said; "at all events I can no longer distinguish the phosphorescent wake made by her propeller; and if that is the case we shall have no more trouble from her. Of course it would have been easy enough for us to have made this pursuit impossible, by removing her propeller when we were working at it yesterday; but the thought occurred to me that, had we done so, the removal might have been discovered, and in that case it is quite possible that suspicion, even though of a very vague and doubtful character, might have fastened upon us, with the result that at some future time, when it may be vitally important for us to repeat the trick, such precautions might be taken as would render its repetition impossible. As it is, the craft has been under steam for a couple of hours, during which, to all appearance, nothing was wrong with her. I do not think, therefore, that anyone is in the least likely to connect us with the mishap."