"There is nothing to be frightened about," she explained. "The air gets lighter and lighter as you go higher, till at last it stops altogether. Then there's only ether left. Birds can't fly in ether because it's too thin. We can, because——"
"Is that why it was good for me to get lighter and thinner?" he interrupted again in a puzzled voice.
"Partly, yes."
"And what happens in the ether, please?" It still frightened him a little.
"Nothing—except that if you fly too high you reach a point where the earth ceases to hold you, and you dash off into space. Weight leaves you then, and the wings move without effort. Faster and faster you rush upwards, till you lose all control of your movements, and then——"
Miss Lake hesitated a moment.
"And then——?" asked the fascinated child.
"You may never come down again," she said slowly. "You may be sucked into anything that happens to come your way—a comet, or a shooting star, or the moon."
"I should like a shooting star best," observed the boy, deeply interested. "The moon frightens me, I think. It looks so dreadfully clean."
"You won't like any of them when the time comes," she laughed. "No one ever gets out again who once gets in. But you'll never be caught that way after what I've told you," she added, with decision.