No doubt Frank was speaking the exact truth when he declared his belief that the revolver had not been charged since the time when Casper emptied it at the pursuing airship, in the hope of either frightening the boy aviators; or else doing some sort of damage.

He stared hard at Frank for half a minute; then with some muttered words, as if he realized the folly of butting up against fate, threw the useless weapon far out on the heaving surface of the lake.

After that a dense silence fell upon them. The men were too down-hearted to want to talk; and there was little that the boys had to communicate, because they were now in a position where they could do absolutely nothing to help themselves; and must depend entirely upon the coming of the tug.

An hour passed, and it seemed very long. All of them were more or less wet because of the splashing waves; but as the air was balmy, they cared little for such a thing as that, if only the tug would show up.

Innumerable times did Andy stretch his neck, and look toward the quarter in which it must appear, if it came at all; but the hour began to extend far into a second one, and as yet there was nothing seen that brought with it a ray of hope.

Worse still the sea was gradually getting more and more tempestuous, it seemed to Andy, though the sky remained absolutely clear, and, there was not a sign of a storm.

If that had been a fog in the far distance which Frank had sighted, the breeze must have long ago dissipated it entirely.

Lower sank the sun, until it was now not more than half an hour above the horizon, if its stay could be measured in the way of minutes and seconds. Oh! if only the friendly tug would come in sight amidst the foam-crested waves! It was really getting to be too much of a good thing, trying to keep the hydroplane from keeling over, with those waves breaking against the frail planes. If this kept up much longer, Frank was very much afraid that Percy Carberry would not be the only boy in Bloomsbury to mourn the loss of an airship.

When, therefore, Andy gave a sudden shout, and announced that he believed he had seen the smoke of the tug wreathing above the waves, all of them looked considerably relieved, even Casper himself; for on second thoughts the yeggman must have decided that it was better to be alive and in prison, than dead, and under the waters of Lake Ontario.

In five minutes they could all see the smokestack of the powerful tug, and for fear lest it should pass by and not do them any good they shouted hoarsely in unison.