"Not I!" said Dave. "I haven't any head for it. I get too dizzy. But I'm going to help Louis build a model aëroplane when we've finished that motor-boat. I'm interested in the mechanical part of it." "But what about Monsieur?" Carol asked Louis. "Have you told him about this?" "No, I haven't," said Louis. "That's why I wanted him to come to-day, so that I could surprise him, too. I'm sorry he couldn't--" Just then some one came and told Louis that the biplane he was to go up in was ready, so that he said good-bye and walked away. We watched him put on his helmet and climb into the machine, and I confess now that I never expected to see him alive again. It's all right when some one you _don't_ know is going up; you're just excited and thrilled. But when it's some one that you _do_, you're simply frozen stiff with fright, and you're morally certain that he'll come crashing to earth any second! Carol and I gripped hands and held our breath, and I believe it was the longest fifteen minutes I ever knew or expect to know. They sailed completely out of sight for a while, and then the suspense was worse. But at last the biplane came back and settled on the field as gracefully as a bird. Louis was wild with excitement when he returned to us, and he says it's the most wonderful experience imaginable. The Imp was so worked up over it that she wanted Louis to persuade his friend to take her up and "loop the loop"! He laughed, and told her it was not allowed, but I believe that for a while she really thought she could tease him into it. There was one other exciting thing that happened. Toward the last a machine went up and something went wrong with the engine when it was about two hundred and fifty feet in the air. It began to droop over in a sort of lopsided fashion, and then began to settle, like a bird that has been wounded in the wing. Before it reached the ground it was almost upside down, and every one was nearly frantic, thinking the man in it would fall out. But he didn't, and at last it came to earth with quite a crash. A lot of people rushed to help the aviator out, Louis among them. He wasn't killed, but they said he had a badly fractured arm, and we saw him being fairly carried off the field. It made me actually sick to think what a horribly dangerous career Louis was letting himself in for. But it didn't seem to disturb _him_ a bit. All he would say was that a careful aviator would never let a thing like that happen. It was late when we came home, so we invited Louis and Carol over to our house to tea, and had a jolly evening afterward. I've had a gorgeous day and, as Louis said, "the surprise of my life." But I cannot help wondering how Monsieur is going to take this piece of news.