"Dear, dear," murmured Mrs. Nesbit helplessly. She disliked exceedingly the scenes to which her daughter often subjected the family.
David only laughed good-naturedly.
"The exhibition is about to begin," he said, and disappeared into the room where the ships were to be put through their performances.
In a few moments six young airship builders appeared, each carrying in his arms the result of his summer's labors. There was vigorous applause from everybody except Miriam, who was too angry with her brother to enjoy the spectacle.
The aeroplanes were all copies of well-known models, except David's, which was of an entirely new and original design of his own invention. It looked something like a flying fish, the girls thought, with its slender, oblong body, gauzy fins at the sides and a funny little forked tail at the stern.
The models were too light for machinery, so rubber bands, secured cris-cross in the bows, when suddenly released with a snap gave the little ships the impetus they needed to fly the length of the gymnasium.
Only four of the six, however, were destined to fly that evening. They soared straight down the big room, as easily and gracefully as great white birds, and dropped gently when they hit the curtain at the other end, their builders running after them as eagerly as boys sailing kites. One of the models fluttered and settled down before it reached the other side, and David's machine, which had commanded most attention because it was different, started out bravely enough, its little propeller making a busy humming as it skimmed along. But it had gone hardly ten yards before it collapsed and ignominiously crashed to the floor.
"I'm glad of it," said Miriam above the din, for everyone had gathered about the young man to offer sympathy and congratulations at the same time.
"It's very, very clever, my boy," said Professor Blitz, "and you'll succeed yet, if you keep at it."
"She wouldn't go far, David," said Grace, stroking the little model, as if it had been a pet dog, "but she's the prettiest of all, just the same."