Frank was ready to follow suit.  It would not be the first time by long odds that the Bird boys had accomplished this speedy method of descending from high altitudes.  There was always an exhilaration about the clever trick that appealed irresistibly to their natures; though Frank would never have attempted it unless reasonably sure that the conditions were favorable for success.

“Hold fast, Andy!” he remarked, quietly.

The hum of the motor suddenly ceased, and with its cessation the hydroplane was turned head-on toward the surface of the lake, four thousand feet below.

Down they went, plunging toward what seemed to be instant destruction; but a steady hand was at the wheel, and the pilot knew just what was necessary to do at the proper instant in order to bring this rapid descent to a stop, and right the airship on a level keel.

But there was no time just then to note what the rival aeroplane might be doing.  Whether the experienced airman in charge managed to stop that downward plunge before reaching the surface of the lake; or failing went to his death, was a matter that did not concern them now, since they had their own affairs to look after.

To tell the truth, Andy’s heart seemed to be in his throat as they made the drop.  As yet they had never tried out the new hydroplane in a trick of this sort; and hence really did not know just how it might act; though Frank must have been pretty confident, else he would never have attempted it.

Given the choice the Bird boys would easily have decided to descend from their lofty height by means of the much safer if slower “spirals,” each circle seeing the aeroplane lower than before.  But since the reckless man in the other air craft led the way, Frank had chosen to follow.  He believed that he could accomplish any feat that was possible to Casper Blue, especially now that the old air navigator had a handicap in the way of a crippled arm.

The water seemed rushing up to meet them; so it looked to Andy, whose anxious gaze was fastened upon the lower depths, as they dipped down in that terrific swoop.  But then, he had seen the same thing when over the land, so that in itself this did not daunt him.

“Oh!”

That exclamation seemed to be forced from Andy’s lips when he felt Frank give a quick turn to the lever that caused the deflecting rudder to again resume a normal position.  The drop of the aeroplane was brought to a gradual stop, and when immediately afterwards the buzz of the motor announced that the propelling power was again at work, it was no wonder that the nervous boy expressed his relief by giving vent to that cry.  There was a world of gratitude back of that word, it can be set down as certain; for no matter how confident Andy might have been concerning his cousin’s ability to accomplish wonders, the new hydroplane was as yet untried in many things.

Now he even dared take his awed gaze from the heaving waters beneath the framework of the aeroplane, and give a thought to those whom they had chased overland and water for nearly three hours.