All this time only a faint humming noise was noticeable, but in a few minutes that became inaudible. Professor Morgan was swallowed up in the darkness and speedily vanished, for he made no use of his searchlight. He must have been half a mile to the northward when he let off a rocket. Ordinary prudence on account of sparks probably caused him to send it sideways. It formed a striking picture,—this germination as it were of a blazing object in mid air, which shot away with arrowy swiftness in a graceful parabola that curved downward, and when about half way to the ground burst into a myriad of dazzling sparks of different hues that were quickly lost in the gloom.
The two spectators waited and gazed in silence, but saw nothing more and returned to their seats in front of the cabin.
“Strange man,” said Harvey, “I wonder whether we shall ever see him again.”
“I don’t think there is much chance of my meeting him, but you may bump against him some time when you are cruising overhead.”
“That seems hardly likely, for the field is too big.”
And yet Harvey Hamilton and Professor Milo Morgan were destined to meet sooner than either suspected and in circumstances of which neither could have dreamed.
Wharton refilled his corncob pipe and puffed with deliberate enjoyment.
“What do you think of him, Mr. Hamilton?” he finally asked.
“He’s wonderfully well informed about aviation, but is cranky.”
“He’s more than that.”