Sambrombon Island made the position of the Republic of Rioguay unique. It was in the territory of San Valodar, consequently San Valodar claimed control of the Corda Channel on the north-east side, and one-half of El Porto Channel on the south-west side, sharing the jurisdiction of that waterway with the Republic of San Benito. Thus, whatever shipping Rioguay possessed could not pass to the open sea without entering the territorial waters of either San Benito or San Valodar; but, by mutual arrangement among the three republics, Rioguayan ships were allowed the right of using El Porto Channel, without payment of dues. This much Peter learnt from a fellow-countryman, the only British subject on the ship, and Mackenzie by name. "The Rioguayans are frightfully proud of this concession," continued Mackenzie. "They are top-dog out here and pretty go-ahead, I can assure you. Too go-ahead for my liking." "How's that?" asked Peter. His companion smiled enigmatically. "You'll find out quick enough," he replied. "The country used to be all right, but of recent years there's been a growing anti-British feeling. Why, I don't know, but the fact remains. So much so, that I'm selling out. I've taken up a piece of land at Barbuda, and I'm returning to Rioguay only to arrange for the disposal of a small mine that I've been working here. Where are you bound for?" "El Toro; that's about five miles from Tepecicoa," announced Peter. "An uncle of mine is an engineer there." "Not Strong--Brian Strong--by any chance?" "Yes," replied Peter. "Do you know him?" "Do you?" asked Mackenzie. "I was only five or six when I last saw him," said Peter. "You'll find him a weird old bird, chock-a-block with comic notions and strange gadgets," declared Mackenzie, with a burst of British candour. "Not a bad sort, though," he added. Just then Peter heard the distinctive drone of an aeroplane engine. It was some time before even his trained eye could detect the on-coming machine, but presently he could see the misty outlines of a huge flying-boat travelling at high speed at a great altitude. Even as he looked, the flying-boat shut off her engine and dived at such a steep angle that it appeared to be out of control. At less than two hundred feet above the water the headlong plunge was arrested. The flying-boat seemed to hang irresolute, her momentum neutralized by the action of gravity. She was a craft of nearly a hundred feet in length, propelled by four powerful engines. For her length, her wing-span was ridiculously small, the planes, three _en échelon_ on either side, being short and with a decided horizontal camber. The absence of struts and tension wires gave Corbold the impression that the planes were of steel. This much he took in before the flying-boat restarted her motors and was quickly lost to sight in the dazzling sunlight.