Having already given a brief description of Dr. Perkins' _Sea Eagle_, it
would be wearisome to dwell in detail on all that was done during the
next week to put that craft in shape for the final tests, upon which so
much depended. It may be said here, though, that besides a visit paid to
Motthaven in an effort to secure the apprehension of the two Daniels, a
search was prosecuted for the missing dinghy. Neither mission proved
successful.
The Daniels, having discovered that Harry was on board the _Betsy Jane_
after they cut that craft loose, had vanished from the little community.
As for the dinghy, it was supposed that they had taken that small craft
with them. At any rate, it was impossible to get any news of their
whereabouts on shore. This may be attributed to a distinct prejudice
felt by the fishing community against the dwellers on Brig Island. Your
down-easter is inquisitive to a degree, and the secrecy under which
operations on the island were carried on was felt as a distinct affront
to the little town. So therefore, although the local authorities
promised every co-operation in seeking out the Daniels and punishing
them for their outrageous conduct, it may be doubted if the efforts went
much further than the mere assurance.
But after all, in the rush of interesting work that was now on hand, the
Daniels were almost forgotten. The _Betsy Jane_ had been towed round
into the nearer cove, where she could be constantly watched, and the
motor boat was used in the operation, the officer of the derelict
destroyer having fulfilled his promise to furnish the boys with a new
spark plug for the engine in place of the one taken by the marauders.
The morning after Harry's return to the island Dr. Perkins had laid down
a systematic plan of action. Frank and Harry were assigned to aid him in
giving the finishing touches to the _Sea Eagle_, while his son and Billy
Barnes were set to work with axes to clear a sort of runway down to the
beach. Both Billy and Pudge would much rather have had a hand in the
mechanical part of the work, but they pluckily went ahead on their
designated duty and stuck to it till a broad path had been cleared from
the summit of the island to the margin of the beach.
When this "roadway" through the brush had been cleared, two lines of
planking, firmly nailed to stout supports, were run down on each side of
it, forming a sort of railway, similar to those from which vessels are
launched.
It was down this runway that it was designed to introduce the _Sea
Eagle_ to her initial plunge. At last the day arrived when all was
complete, and the _Sea Eagle_ was pronounced fit for the test. During
the night before this event not one of the boys got more than half his
usual allowance of sleep. In fact, it is doubtful if Dr. Perkins enjoyed
much more repose.
By earliest dawn they were out, to find every promise of a glorious day.
Breakfast that morning was a hasty apology for a meal, and hardly had it
been gulped down before all hands were in the _Sea Eagle's_ shed. As has
been said, the boat-like underbody of the craft had been mounted on a
wheeled frame before it was assembled. All that had to be done then to
get everything in readiness for the final test was to make fast a block
and tackle to a stoutly rooted tree, and then wheel the _Sea Eagle_ to
the top of the inclined runway.
When the odd-looking craft was safely poised on the top of the rails the
loose end of the tackle was made fast to the stern of the substructure,
and Billy, Pudge and Harry were delegated to "belay" the rope as
required. Frank and Dr. Perkins seated themselves in the "boat," and at
the words "Let her go!" the _Sea Eagle_ in her wheeled frame began her
descent down the runway. By means of the tackle the three boys at the
summit of the incline easily controlled the novel craft's descent,
stopping from time to time while Dr. Perkins and Frank made a survey to
see that all was going well.
"Bunting and buttercakes!" grumbled Pudge, as the boys alternately "let
go" and "hauled in" on the tackle, "I thought a launching was more of a
gala event than this."
"I guess the doctor is too anxious to test out the _Sea Eagle_ to bother
with the trimmings," laughed Harry; "it's _results_ that he's after."
As a matter of fact, the launching of the _Sea Eagle_ was a very mild
affair compared with what might have been expected. Had the villagers
ashore known of it, doubtless a small fleet of boats would have been
lying off the cove to witness it, but it was for that very reason that
the deepest secrecy had been observed, and that the early hour had been
chosen. As Dr. Perkins said, he "didn't want any fuss and feathers" made
over what was merely, after all, an experiment.
The rolling glide down the runway was made without incident, and at last
the bow of the _Sea Eagle's_ "hull" struck the water. A cheer went up
then that, rang shrill and clear out over the calm sea. Even Dr. Perkins
joined in the enthusiasm, as well he might, for the goal of his ambition
was in sight at last.
The _Sea Eagle_ had been sent on her initial voyage without the
aeroplane wings or the auxiliary lifting bags being attached. It was
desired, first of all, to try out her qualities as a water skimmer. As
soon as she was fairly afloat, the wheeled carriage on which the descent
had been made was drawn ashore. Having been weighted before the start
was made, it of course sank under the _Sea Eagle_ when the sea and air
craft floated, thus allowing it to be reclaimed with ease.
"Looks like a butterfly with its wings clipped off," commented Billy
Barnes as, with the others, he hastened to the beach as soon as their
task was over.
Indeed, the odd-shaped hull, with its naked frame and two gaunt aerial
propellers, did look strangely incomplete. But the boys knew that the
wings were all ready for instant attachment. In fact, it was one of the
features of the _Sea Eagle_ that the craft was capable of being taken to
pieces and put together again with very little loss of time or labor.
As the hydroplane portion of the _Sea Eagle_ floated clear of the
weighted frame in which it had made its journey to the beach, Frank
looked inquiringly at the inventor. His hand was on the self-starting
device which put the powerful motor in operation. Dr. Perkins was
actually pale, and Frank could see that his strong hand shook
perceptibly as he nodded his head.
But he mastered his nervousness quickly, and, grasping the
steering-wheel in a firm grip, he spoke:
"You can start up now," he said.
Frank turned the starting handle, admitting a charge of gas to the
cylinders. Then he pressed a button and instantly the motor responded
with a roar and a series of explosions, like those of a battery of
gatling guns going into action. Having started it he admitted gasolene,
and adjusted the carburetor till the cylinders were all working
steadily.
Close to Dr. Perkins' hand was a lever. This, when moved, "threw in" the
clutch connecting the motor with the driving mechanism. Directly Frank
had finished tuning up the motor Dr. Perkins' hand reached for the
lever. He jerked it nervously back. There was a whirr and a buzz, as the
chains whirled the twin propellers round, and at the same instant the
_Sea Eagle_ darted forward like an arrow from a bow.
Faster and faster she went, getting up speed with seemingly marvelous
rapidity. But instead of driving deeper into the water, under the
pressure of the aerial propellers which rushed her forward through the
atmosphere, the faster the _Sea Eagle_ was driven the more lightly did
the craft skim the surface of the water, till at top speed--2,000
revolutions a minute--her bottom barely touched the water. This was owing
to the peculiar construction of the hull, which was designed so as to
"plane" the water in exactly the manner it did.
Cheer after cheer broke from the lads on shore as they saw the swift
craft dart off, slicing the tops of the small waves like a cream
skimmer. Dr. Perkins circumnavigated the island three times before he
gave the signal to Frank to slow down. Then, releasing the clutch, the
inventor allowed the _Sea Eagle_ to come to rest, with its bow almost
touching the beach.
"Now we will have a weight test," he announced; "come on, boys."
The lads ashore surely needed no second invitation. Without bothering to
remove shoes or stockings they waded into the water and out to the _Sea
Eagle's_ side. In less time than it takes to tell it they were swarming
over the side of the cockpit and struggling for positions near the
engine. But Dr. Perkins made them arrange themselves so that their
weight would be evenly distributed. Ben Stubbs and Harry sat in the
extreme stern, while Pudge and Billy occupied opposite seats amidships.
This done, off darted the _Sea Eagle_ once more, and speedily set at
rest all doubts as to her capability to "plane," or skim the water,
under an added load.
"It's like riding on a floating island over a sea of raspberry ice cream
soda," declared Billy, when he was asked later to describe his
sensations.
But a severer test awaited the _Sea Eagle_, namely, the trying out of
her capacity actually to rise into the air. The craft was run partially
ashore, and the great wings bolted in place and the stay wires adjusted.
The stay wires were tightened by turn buckles till they were taut as
fiddle strings, assuring stability of the wings. But in addition the
wings were, of course, partially supported on the light but strong
skeleton framework before noticed.
Much to the disappointment of the others, only Frank and Harry Chester
and Dr. Perkins were to participate in the flying trials. But they took
it all in good part, being promised rides later if the tests were
successful. As before, the _Sea Eagle_, after she had been backed off
and the propellers started, skimmed along the top of the water like a
flying fish. But all at once the watchers on shore saw her rise bodily
from the water and soar upward into the air. Higher and higher went the
craft, gliding like a gull through the ether. It was an inspiring sight,
and a perfect tornado of yells broke from Ben Stubbs, Billy and Pudge.
But those on board the _Sea Eagle_ could not hear the sounds of
enthusiasm above the roaring of the motor.
Under Dr. Perkins' skillful guidance the _Sea Eagle_ climbed the aerial
staircase till a height shown by the barograph to be almost 4,000 feet
had been attained.
"Now to test the buoyancy apparatus," cried the doctor suddenly. "Shut
off power, Frank."
Frank, who knew what was coming, obeyed the order and turned a valve
admitting the pure hydrogen gas from one of the cylinders into the
buoyancy devices. Instantly the upper wings swelled, till they resembled
puffed-out mattresses more than anything else, and the "volplaning"
downward movement was perceptibly checked. But, setting the descending
device, Dr. Perkins headed the _Sea Eagle_ for the water, and,
skillfully manipulating the craft, landed it as lightly as a drifting
feather on the water by the hull of the _Betsy Jane_.
Now came a further trial of the capabilities of the wonderful new craft
which, so far, had proven such a success. Dr. Perkins set the planes in
a rising position and allowed the _Sea Eagle_ to hover above the _Betsy
Jane_, like the bird for which the aerial craft had been named. Then
suddenly he began a rapid descent, landing finally on the very summit of
the inclined runway before mentioned. The sides of the _Sea Eagle_ were
equipped with large metal hooks, which were hastily thrown out by the
boys and attached to four "eyes" arranged to receive them.
When this had been done the suction pump was set to work, and the
inflated wings emptied of the gas, which was forced back into its
receiver, and the valve closed. It was calculated that less than two per
cent of the gas was lost during the process. The _Sea Eagle_ was now
once more a simple hydroplane, without any buoyancy device.
At a word from Dr. Perkins the hooks which had held the machine in place
were disengaged, and instantly the craft began to glide down the runway.
Half way down the engine was started, and when the graceful craft
reached the abrupt end of the incline, the _Sea Eagle_ went soaring off
into space like a huge white-winged bird. This test was regarded by Dr.
Perkins as the most important, for it proved the entire practicability
of launching the _Sea Eagle_ from a ship far out on the ocean.
After circling in the air a few times the tests were concluded by a
rapid drop toward the earth right above the summit of the island. Just
as it seemed as if the new craft must end her career by being dashed to
bits against the construction shed, a skillful twist of the steering
device sent her soaring upward once more. Two more swinging aerial loops
were described, and then, with hardly a jar or vibration, the _Sea
Eagle_ was brought to rest by her inventor, almost in front of the shed
where she had been assembled.
As the thrilling and wonderful trip was concluded, the boys came
pressing about Dr. Perkins, showering congratulations and good wishes.
"Why, one could fly across the ocean in such a craft," declared Frank
enthusiastically.
The others laughed, but, to their astonishment, Dr. Perkins looked
perfectly serious.
"I have a long trip in view," he said, "a flight that will test every
wire and bolt in the _Sea_ _Eagle's_ construction. I did not announce
this before for I wished first to see if everything worked
satisfactorily."
"No doubt about that," said Billy Barnes with enthusiasm. He had been
dodging about the great flying machine, taking photos from every
possible angle.
"No," admitted Dr. Perkins; "I must say that so far the _Sea Eagle_ is
all that I could desire. But the final test will put that beyond the
shadow of a doubt. Do you boys wish to undertake a long trip?"
"Cookies and cucumbers! Do we!" roared Pudge, as the others pressed
eagerly about to hear the unveiling of the doctor's plan.