"Why, what do you mean?" he cried. "I'll try and show you," said Will. "Lie down here. It's quite dry." Dick threw himself on the short soft turf, and Will pulled out a pocket-book, took the pencil from its loop, and, spreading the book wide, began after a fashion to draw what learned people call a diagram, but which we may more simply speak of as a sketch or figure of what he wished to explain. It was very roughly done in straight lines, but sufficiently explanatory, especially as Will carefully followed the example of the sign-painter, who wrote underneath his artistic work, "This is a bear." Will began by drawing a horizontal line, and under it he wrote, "The sea." Then he turned the horizontal line into a right angle by adding to it a perpendicular line, by which he wrote: "The cliff." From the top of that perpendicular he drew another horizontal line, and above that he wrote, "Top of the cliff." "Now, then," he said, "these little arrows stand for the wind blowing right across the sea till they come to the face of the cliff;" and he drew some horizontal arrows. "Yes, I see," said Dick, helping with a finger to keep down the fluttering leaves. "Well; now the wind has got as far as the cliff. It can't go through it, can it?" "No," said Dick. "And it can't go down for the sea." "Of course not." "It can't go backwards, because the wind is forcing on the wind." "Yes," said Dick. "Hold still, stupid!" This last to the fluttering leaf. "Where is the wind to go, then?" asked Will. "Why, upwards of course," cried Dick. "To be sure," said Will. "Well, it strikes against the face of the cliff, and that seems to make it so angry like that it rushes straight up to get over the top." "Of course it does," said Dick; "any stupid could understand that." "Well," said Will, "the top's like a corner, isn't it?" "No!" cried Dick; "how can it be?" "Yes, it is," said Will sturdily; "just like a corner, only lying down instead of standing up." "Oh! very well; just as you like," cried Dick. "Now suppose," said Will, "you were running very fast along beside a row of houses like they are at Corntown." "Very well: what then?" "And suppose you wanted to run sharp round the edge of the corner, and I was hiding behind it, and you wanted to catch me." "Well, I should catch you," said Dick. "No, you would not. You couldn't turn short round, because you were going so fast; and you'd go some distance before you did, and you'd be right beyond me, and you'd make quite a big curve." "Should I? Well, suppose I should," said Dick, rubbing one ear. "Well," said Will, making some more arrows up the perpendicular line which represented, the face of the cliff, "that's how the wind does. It goes right up here, and gets some distance before it can stop, and then it curves over and flies right over the land, getting lower as it goes, till it touches the ground once more. There, that's it; and those two dots are you and me."