He certainly must have found _something_, because he came to the end of his journey and travelled no more. He had no need to travel any more. His task was done: the puzzle was found out; and he had arrived at “the other end of the world.” Only it was no “end” at all, but just the very same spot from which he had started. For he had actually found his way back to his own old home again. Don’t you think he must have been rather astonished? It was not at all what he had expected. Suppose that a spider, living in the middle of a very big plain, were to make up his mind to walk to the outside edge of that plain, and see what might chance to be there. And suppose that, having climbed little hillocks, and crossed little brooks, trying always to keep steadily in the same forward direction, he were to find himself all at once back on the very same spot from which he had first set forth! He would no doubt be a good deal surprised; and if he had sense to think the matter over he would see plainly that he had _not_ managed, after all, to keep going straight forward, but that he must somehow have turned round without knowing it and gone back to his starting point. The man in the story made no such mistake, however. He did not turn round. He went always on, and on, in exactly the same direction. Yet in the end he found himself at home! There is the curious part of the matter. If the world were a flat plain, like the top of a large round table, the man could not have done this. It would be out of the question. He might have turned round and walked back; he could not have walked steadily onward and onward, farther and farther away from his home, only to find himself suddenly there again. The thing would be impossible. Whether any living man ever took such a journey round the world is more than doubtful. But I can assure you of this: that if any man ever _did_ take such a journey it would end just as that man’s journey is said to have ended. By keeping straight forward, always in one direction, and by going on long enough, he would in time get back to his own house again. How could he? That is the question. If a spider were to walk on for ever, straight across a flat plain, he would never get back to his starting-point. But the world on which we live is not a flat plain. For a long while men believed that it was; and they made a mistake. Let us think again of a spider--one of those tiny red spiders often found in a garden--and let us suppose this wee red spider to be standing on a huge round globe, as large as a house. Suppose that the spider, having very short sight, fancied himself to be on a flat table and resolved to take a walk to the further end, to see what he might find there.