"Mr. Dent has told me of the interest he feels in your theory of tides and currents, and especially in how they might have affected the ship _Rufus Stevens_. And we have come to-night to hear more of it, if you are of the mind to tell it." "We have a curiosity concerning your idea," said Christopher cautiously. "And so, if there is any more to tell, we beg of you to tell it plainly, for it may be a thought with a deal of value, and which could be put to a practical use." Never had Tom Horn looked so worn and fragile as he did at that moment, sitting with the mass of calculations before him and with the candle-light upon him; never before had the strange, luminous quality that he threw off been so pronounced, never had the odd, hopeful look in his eyes shown so fully through their fixed despair. "I will say what I can," he said, "and that is not much; for no man can speak with authority on things urged by powers whose weight he can only surmise. But this I know: In the south region of the world, the edge of Africa and that of South America make the two sides of a vast throat, and through this the waters warmed by the tropics force themselves northward. The current clings to the American side and, when opposite the mouth of the Amazon, begins to thicken. It sweeps between Trinidad and the Barbados into the Carribbean; it rounds the West Indies to the south and curves into the gulf, and then, out and away, along the North American coast." "And holds all its parts to itself on the way," marveled Christopher. "That is wonderful, indeed. It is as though it were a vast living thing." "From the north," said Tom Horn, and he pointed a long finger at one of the maps on the wall, "comes a second current, cold, holding to the coast and meeting the warm current where the ocean's bed rises so abruptly off Newfoundland. Here the two merge and swing off toward the east. But the land turns them south; holding to the African rim they flow back through the great throat, completing the circle. And somewhere inside that circle," said Tom Horn, "is the Sargasso; it lies to the south of the Azores, to the west of the Canaries, and northwest of the Cape Verdes Islands, a vast pool of slack water; and into it is drawn all those things which the currents have ravished from the world." "It is your thought, then," said mademoiselle, "that the ship _Rufus Stevens_, if still afloat, may have fallen into the grip of this great circle. But might it not be that the storm blew her out of reach of the currents? Who can say what happened in a great wind like that?" Tom Horn took one of the sheets from the table.