A space of about two feet at each end of the pontoons had been partitioned off, so as to form four tanks in which water and gasolene could be stored. Caps screwed over vent-holes provided opportunity to insert a small pump when it was necessary to draw on the emergency supplies or water ballast thus carried.
Lone Cove, a small sand-bordered inlet off the Sound, was reached after a run of about two hours and the tanks—boxed in long wooden cases so as to avoid the scrutiny of any villagers who might prove too curious—were transferred to a wagon and carried to the small wharf where the Ocean Spray, the launch the boys had chartered for their experiments, lay at anchor.
Her owner, an old beachman, at once turned the craft over to the party and expressed a lot of curiosity, which was not gratified, as the boys knocked the cases off the "pontoons" and then floated them. With the boards from the cases, a sort of platform was then constructed between the floating tanks and lashed to them with stout wire. The wonderment of the old waterman was in no wise decreased when he saw the boys then fall feverishly to work and load the dinghy, attached to the launch, with large stones. When they had her piled to the water line, they pulled out to where they had anchored the tanks with their bridge-like platform, and commenced to place the rocks on board till Frank estimated that there was as much weight reposing on the pontoons as they would be called upon to bear when the Golden Eagle was super-imposed on them.
As Frank had figured, the tanks were immersed for about a third of their depth under the weight, and when the burden of the boys and Bluewater Bill was added, they sank till about half their circumference was above and half below the water. The whole contrivance was then taken in tow of the Ocean Spray, in order to ascertain just how she would behave under the speed at which it was hoped the propellers of the Golden Eagle would drive her when the contrivance was affixed to her bed plates.
It was a perfect day, and as the boys emerged from the mouth of the inlet and the blue expanse of the Sound spread before them, they fairly shouted with delight at the sparkling water and invigorating air.
"How long are you going to stay out?" asked Bluewater Bill, as the Ocean Spray plunged bravely forward and the sharp-nosed pontoons, to the boys' delight, clove the water behind without making any noticeable resistance.
"The Golden Eagle will drive over any seaweed that ever floated on these," shouted Billy excitedly as he gazed back.
"How long are we going to stay out?" repeated Frank, in reply to Bluewater Bill's question. "Oh, not more than an hour or so, but it's such a glorious day I'd like to keep on going for a while."
"So would we," chorused the others.
"Wall," was the old-sailor's rejoinder, "I don't want to be a spoil-sport, boys, but do you see that haze yonder?"