"But perhaps the biplane might sink, sir," declared Elephant, still showing extreme nervousness. "And what if Frank or Andy happened to be caught in the wires that stay the planes? They might be drowned, you see. Accidents can happen, even to the two smart Bird boys."
"No danger of any such catastrophe, I give you my word," went on the gentleman. "And when you learn the truth, you'll thank me for restraining you from acting in a foolish manner. Here, take a look through this glass I chance to have along in the car. What do you see now?"
Larry accepted the binoculars, and immediately adjusted them to his eyes.
"Well, of all the things I ever heard of!" he slowly ejaculated.
"Let me look, Larry," exploded Elephant, as he deftly "hooked" the glasses away from his companion's hands, and immediately clapped them to his own eyes, to let out a shout of amazement. "I declare if the old thing ain't floatin' like a big duck. Talk about her sinking, you couldn't push that wonder box down under the surface. Some more of Frank's magic; he's got 'em all queered a mile, Larry."
"Listen," remarked Mr. Marsh, quietly. "There's nothing so very wonderful about this new stunt of your friend, Frank. Those shining things you noticed about the biplane happened to be a couple of new aluminum pontoons under the craft, meant to float the whole affair whenever it drops in the water. They will be in common use shortly. And that machine is what we call a hydroplane—that is, it will prove to be as much at home on the water as in the air."
"What d'ye think of that, Elephant?" cried Larry, ready to swing his hat, and give a loud whoop to let the young aviators know that friendly eyes had been watching their startling maneuvers. "Ain't they all the candy, though? Why, Perc Carberry never could get up early enough in the morning to best the Bird boys."
"They float all right," remarked the other boy, still gazing through the fine pair of marine glasses that seemed to bring the biplane within touching distance. "But how under the sun can they start up again? Don't they have to take a run on them bicycle wheels first?"
"Watch and see," laughed Mr. Marsh. "A hydroplane can rise from the surface of the water just like a wild duck might. The propeller starts to working, the machine is sent swiftly along, and soon leaves the water, to soar upward as the planes are moved accordingly. There they go; now, keep tab on what they do, Longley."
He took the glasses from Elephant and placed them to his own eye, as though it might be of the greatest importance that he see distinctly every little movement of the daring young aviators.