Hal had to undergo examination for heart action, and short-sightedness, and color blindness, and sense of balance and equilibrium. He was thumped and spun and eye-tested till he began to imagine that he really must have some outlandish physical defects. It came as an exhilarating shock to him when the doctor thumped him in the back and grunted, "Umph,--prime condition,--fellow with a constitution like that could fly to the moon!"