"That's the first," remarked the boy's informant. "We'd better get under shelter, they'll come fast and furious soon." Passing through a low passage connecting the house with the hurricane wing, Stuart noticed that, beside the massiveness of the structure, it was braced from within. "In case the house should fall on it," the scientist observed, noting Stuart's glances. "I've no wish to be buried alive. In any case, I keep crowbars in the wing, so that, in case of any unforeseen disaster, a breach could be made in the walls and we could get out that way." They entered the hurricane wing. It was not as dark as Stuart had expected. The scientist, anxious to observe the storms when they should come, had built into the wall two double dead-eye windows, such as are used in the lower decks of liners and which can resist the impact of the heaviest waves. The crimson light had gone. The vivid sunset reflections, now thrown back from the black arch, yet gave a reddish smokiness to the livid and sickly green which showed, from time to time, beneath the underhanging masses of inky black. The sky to the north and to the south had a tortured appearance, as though some demon of a size beyond imagining were twisting the furies of the tempest in his clutch. "You asked," said the scientist, speaking in the hurricane wing, as quietly as he had on the verandah, and paying absolutely no heed to the moaning and praying of the negroes huddled in the darkest corner, "what makes a hurricane whirl. Yet, in the heavens, you can see the skies a-twist!" A second rain-squall struck. Thick as were the walls, they could not keep out the wailing shriek of the wind, nor the hissing of the rain, which flashed like a continuous cutting blade of steel past the windows. The hurricane wing could not rock, it was too low and solidly planted for that, but it trembled in the impact. After a couple of minutes came a lull, and Stuart's ears were filled with the cries and howling of the frightened negroes, not a sound of which had been audible during the squall. The scientist continued his talk in an even voice, as peacefully as though he were in his study. "You asked what could set the skies a-twist. I told you, the earth's rotation. For, Stuart, you must remember that a hurricane is not a small thing. This heated region of the air of which we have been speaking, with its outer belt of cooler air, and the descending warm air beyond, is a region certainly not less than five hundred miles in diameter and may be a great deal more.