A switch snapped. Dick found himself instantly in a rotunda, roofed with glass, sections of which were raised to a height of three or four feet from the wooden base, admitting a gentle breeze. Three or four men were moving about in it, but these wore the black uniform with the silver braid, and Von Kettler's manner was deferential as he addressed them, jerking his hand contemptuously toward Dick. Grins of derision and malice appeared on all the faces. Save one, an elderly officer, apparently of high rank, who came forward and raised his hand to the salute. "Captain Rennell," he said, "we are at war with your nation, but we are also, I hope, gentlemen." He turned to Von Kettler. "Is it seemly," he asked, "that an officer of the American army should be brought here in chains and cords?" "Excellency, it is His Majesty's command," responded Von Kettler, with a servile smirk that hardly concealed his elation. "Moreover, the American is to witness the forthcoming destruction of the Yankee fleet." The elderly officer reddened, turned away without replying. Dick looked about him. * * * * * There was less machinery in this room. The iron pillar that he had seen came through the floor and terminated some five feet above it in another of the opaque glass domes, filled with iridescent fire. About it was a complicated arrangement of dials and gauges. In the centre of the room was a sort of camera obscura. A large hood projected above a flat table, and an officer was half-concealed beneath it, apparently studying the table busily. "Come, American, you shall see your navy on its way to destruction," said Von Kettler, beckoning Dick within the hood. The officer stepped from the table, whose top was a sheet of silvered glass, leaving Von Kettler and Dick in front of it. Dick looked. At first he could see nothing but the vast stretch of sea; then he began to make out tiny dots at the table's end, terminating in minute blurs that were evidently smoke from the funnels. "Your ships," said Von Kettler, smiling. "This is the dirigible." He pointed to another dot that came into sight and disappeared almost instantly. "They are a hundred and fifty miles away. Explain to your friends in Washington that our super-telescopic sights are based upon a refraction of light that overcomes the earth's curvature. It is simple, but it happens not to have been worked out until my Master commanded it." Dick watched those tiny dots in fascination, mentally computing. At an average speed of fifty knots an hour, the squadron's steaming rate, they should be off the coast within three hours. The dirigible would take two, if it went ahead to scout, as was almost certain. * * * * *