To get ashore Frank had first to swim off to the motor boat, for the skiff, as we know, had vanished. He then ran the engine-driven craft in alongside some rocks that sloped down into deep water, and from that elevation the party embarked. A quick run was made to Motthaven, from whence a description of Duval was wired to the metropolitan police, and the local authorities urged out of their usual lethargy by promises of a reward if Duval was found. Late that afternoon the search yielded results in the finding of the abandoned skiff, and the discovery of the hut in which the Daniels had been living since the boys had instituted proceedings against them.
Some evidences of a hasty departure were found, but no clews that would give any idea of whither the fugitives had proceeded. In fact it was only by piecing together some scraps of torn paper that it was discovered that the hut had been used by the Daniels as a refuge.
“Well,” said Dr. Perkins that evening, after they had bidden good-by to Mr. Sterrett and his friend, who had returned to New York, “well, in my opinion the less time we lose in getting to Black Bayou the better it will be, for, to my mind, there is little doubt that Duval means to forestall our friend, Ben Stubbs, in ransacking the wreck.”
The others agreed that this seemed highly probable, and Dr. Perkins made immediate arrangements for a caretaker to occupy quarters on Brig Island during their absence. This done, a return was made to the little settlement, and the next day final preparations were made for the adventurous trip through the air. The Sea Eagle was provisioned, and a light wireless apparatus installed, the stay wires being used as aërials. Of course the instruments were not so strong as those used at the shore station, but it was calculated that they had a capacity of about twenty miles over land, and forty above the sea, depending, of course, a good deal on the wave adjustment and the weather conditions.
Twenty-four hours after the adventurers had started work on the Sea Eagle, the craft was ready for her dash. Ben Stubbs, Pudge Perkins and Billy Barnes were to go to New Orleans, there to await the arrival of the party. Their departure took place amid regretful wails from Pudge, who loudly declaimed:
“Aërials and ant-hills! I don’t see why we can’t go by the Sea Eagle.”
But Dr. Perkins’ word was law and he had decided that the fewer persons who took part in the test the better the chance of success would be, and as Frank and Harry were both experienced aviators he placed great reliance in their aid. The morning after the departure of the New Orleans-bound passengers the caretaker and his family arrived. They were honest folk from the shore, who could be trusted to look after the many valuable devices on the island, and keep curiosity seekers off till the party returned. For Dr. Perkins had decided to use Brig Island as a permanent workshop, and expected, if the Sea Eagle proved a success, to build many craft like her and dispose of them at good prices. The working of the electric fence was explained to the caretaker; but he declared:
“I reckon my old gun will do more to keep undesirables off than any of them electric didoes.”
There was now nothing more to do, the caretaker being duly installed, but to take to the air, in what was, at that date, the most unique aërial craft in existence. For the voyage, beside the provisions and extra fuel and oil, life belts had been provided, and not a detail had been overlooked. It was seven o’clock on a fine, breathless morning when Dr. Perkins gave the order, “Start up the engines!”
A thrill shot through both Frank and Harry at the words. Experienced in aërial adventure as were both boys, they could not but feel that they were embarking on the most adventurous undertaking of their lives.