“By jove, so it is,” exclaimed Harry, “how stupid of me not to have realized that. What does it all mean do you suppose?”
“It means,” replied Frank, “that we will not leave the aerodrome unguarded for a minute day or night till we are ready to make our start for Florida.”
CHAPTER IV.
A PLOT DISCOVERED.
In accordance with Frank’s resolution the three young members of the party and Ben Stubbs divided the night into four watches which were religiously kept, but rather to Frank’s surprise nothing occurred to excite suspicion. The next morning Le Blanc, who had driven into town, returned shortly before noon with a letter from the Secretary of War which contained information of much interest to every member of the projected expedition.
“I have arranged with the Department,” it read in part, “to have the torpedo destroyer Tarantula detailed to duty along the Florida coast and you can keep in touch with her by wireless. For this purpose, besides the apparatus attached to your air-ship, I have ordered a complete field outfit to be forwarded to you,—of the kind with which several western posts have been experimenting of late and which has proved entirely satisfactory.
“The instrumental part of the outfit—i. e., the keys, detector, condenser, tuning-coil, etc., are permanently fastened into or carried in a steel-bound trunk, but little bigger than an ordinary steamer trunk, and weighing about one hundred and fifty pounds. Two storage batteries, both sufficient for ten hours of continuous sending, accompany the outfit, and come in wooden cases which form supports for the trunk when the outfit is in use.
“A mast of ten six-foot sections, which can be jointed together and set up in a few minutes, forms your aerial pole and each section is coppered so as to provide a continuous conductor. In another box are packed the aerial wires, extra rope, wire-pegs, etc., as well as a waterproof tent to protect the outfit from the weather. Of course a charging station is a necessity and another case contains a small, but powerful gasolene motor and generator. Another attachment for use with the appliance is a combination Malay and box kite carrying a cord of phosphor bronze, wire-woven about a hemp center. There are eight hundred feet of this wire wound on a reel. If for any reason the work of setting up and attaching the pole and its aerials is considered to be too lengthy an occupation it is a simple matter to send up the kite, its wire rope acting as an aerial in itself.”
The boys grew enthusiastic over this description. The outfits seemed from the account to possess the merits of portability and efficiency and in the country into which they were going portability was a strong feature in itself. It was this very question that had caused Frank, when designing the new Golden Eagle, to so construct her that she could be taken apart and the various sections boxed in a very small capacity each box weighing not more than fifty pounds with the exception of that containing the engine which weighed one hundred and fifty without the base.
That afternoon the boys worked like Trojans on the Golden Eagle II with the result that shortly before sundown they had progressed to a point where the air-ship was ready for the attachment of the engine. They were all surprised, and somewhat startled, when their solitude was invaded, just as they were thinking of knocking off work for the day, by a loud rap at the doors of the aerodrome. Frank opened the small flap cut in the big door and stepped out to see who the intruder might be.
He was greeted by a boy of about his own years smartly—too smartly—dressed, and with a confident overbearing manner.