And, to facilitate as much as possible the process of coaling, Milsom caused a broad gangway, nearly six feet wide, to be rigged between the two vessels, so that the porters might pass to and fro freely without obstructing each other. And, singularly enough, this gangway happened to be rigged exactly over the ash port, which was thus quite effectually concealed from the view of even the most prying eyes. And there undoubtedly were several pairs of eyes very curiously and intently watching everything that was happening aboard the English yacht, not the least intent among them being those of the custom-house officer, who planted himself upon the bridge of the _Thetis_, fully determined that nothing great or small should be passed from the yacht to the coal hulk without his full knowledge and consent. Thus, thanks to the exceeding care with which Milsom had made his dispositions, Jack--who, with the two Montijos, was supposed to be down below--and Macintyre, fully equipped in their diving dresses, and with their tools slung to their belts, had not the slightest difficulty in leaving the yacht unobserved, and descending to the bottom of the harbour by way of a diving ladder. The water being shallow and tolerably clear, and the sun high enough in the heavens to throw a strong light down into it, the two adventurers were able to see well enough to be able to pass from the yacht to the torpedo boat without any other guide than that of their unaided eyesight; and within ten minutes the pair found themselves beneath the bottom of their quarry, the keel of which was, as Jack had anticipated, within about three feet of the ground. The boat, they found, was driven by a single propeller protected by a skeleton frame forming the boat's keel and sternpost, and to climb into this frame occupied Macintyre less than a minute, helped as he was by Jack. Macintyre's first act was to subject the propeller nut to a very careful examination, after which he fixed a big spanner in position and threw his whole weight upon it, assisted by Jack, who was pulling at a rope attached to the extreme end of the spanner handle. The nut, however, was rusted on so effectually as to be immovable, so Macintyre climbed down and, by means of a slate and a piece of chalk, consulted Jack as to what was best to be done to overcome the difficulty. Looking up, and studying the structure of the boat's stern intently, Jack saw that by steadying themselves by the rudder chains they could both climb up and stand upon the arm of the spanner, when, by bracing their shoulders against the boat's overhanging stern, they could bring the whole of their united strength to bear, and thus possibly start the nut. By means of a diagram and a few words chalked upon the slate Macintyre was soon made to comprehend what Jack meant, and then they both climbed up and, with considerable difficulty, arranged themselves in the required position. Then, bracing their