THE GREAT TEST.
A week later to the day on a sunshiny, windless morning, the
Wondership was run out of its shed, glistening with new paint and with
every bit of bright work burnished till it shone and sparkled like
newly-minted silver. Amidships on the craft, the general construction
of which is familiar to readers of foregoing volumes of this series,
was a square metal box with small wires leading to long copper wires
stretched from end to end of the Wondership's body.
These long copper wires were to form the aërials by which the messages
from Mr. Chadwick's workshop were to be caught. The smaller wires
underneath were connected with the metal work of the engine. These
wires formed a "ground" similar to the kind employed in aërial
wireless telegraphy.
The details of the Wondership having been fully described in the Boy
Inventors' Flying Ship, we shall not enter here into any but a brief
and general description of the craft. The Wondership, then, was a
combination of dirigible balloon, automobile and boat. Her motive
power was furnished by engines driven by an explosive volatile gas
which was also used when occasion arose to inflate the bag of the
balloon feature of her design. The gas was generated in the lower part
of the craft's semi-cylindrical metal body.
On land two big aërial propellers, geared to the engine, drove the
Wondership swiftly along on four solid-tired wheels. When it was
desired to take to the air the balloon bag, which was neatly folded on
a framework supported by upright stanchions above the body of the car,
was inflated by turning on a valve connecting with the gas tanks in
the base of the body.
When the Wondership was intended to navigate the water she was driven
by the same aërial propellers that afforded her motive power on land
or in the air. She then became what may be called a hydromobile. If it
chanced to be rough weather, special hermetically sealed panels could
be drawn together, completely enclosing the body and making the craft
a water-tight "bottle." Ventilation was provided in such a case by a
hollow telescopic tube which reached twenty-five feet into the air. It
was divided in two. Fresh air was drawn by a fan down one section,
while the stale air in the "cabin" was forced out by a similar device
up the other part of the tube. Stability was afforded by hollow
pontoons, which worked on toggle joints, and could be raised or
lowered as desired.
With the aid of Jupe, the gas bag was inflated to a point where only a
slight additional quantity of gas would cause the craft to shoot
upward to the sky. When all was ready a test of the instruments was
made and they were found to be working perfectly. The powerful
alternator on the Wondership was, of course, worked by the same motor
that drove the big propellers.
"Well, I guess there's nothing to keep you back now," said Mr.
Chadwick, who looked pale and ill after his long days and nights of
work on his invention.
"No, we're as ready as we ever will be," said Jack, making ready to
climb into the machine above which the big yellow balloon bag was
billowing and sending impatient quiverings through the Wondership.
"I want you to promise me one thing, dad," said Jack, when he had
climbed into the driver's seat, in front of Tom, whose duty it was to
look after the engine.
"What is that, my boy?" asked the inventor.
"That after this test, whatever the result may be, you will take a
long rest."
"Yes, I will, I must," agreed his father. "I've been working too hard,
I guess, but in the excitement of perfecting the radio telephone I
hardly noticed it. But recently I've had dizzy spells."
"Two weeks' rest will make you well," declared Jack, as he adjusted
the controls.
"Good-by and good luck," said his father.
Both boys waved their hands.
"All ready, Tom?" hailed Jack.
The other boy nodded and then turned on a valve so that with a hissing
sound additional gas rushed into the bag. Jack pulled a lever. The big
motors roared and a queer, sickly smell of burned gas filled the air.
The propellers began to revolve slowly and then increased their speed
till they became a mere blur.
"Dere she go! Gollyumption, dere she go!" cried Jupe, capering about.
As the old black spoke, the Wondership shot up like a rocket, tilting
her nose slightly into the air. But the next moment Jack had her on an
even keel. In an incredibly short space of time those watching below
saw her only as a glinting, golden speck against the blue sky,
circling like some strange bird far above their heads.
"Now for the tests," said Mr. Chadwick, as he hastened to his
workshop.
He set the big alternator at work at top speed. It droned like a gaunt
bee. The inventor's face, worn by his anxious vigils at his
experiments, was as keen as a hawk's, while he adjusted the
instruments and placed his long, lean fingers on the tuning device.
Far above the earth Jack and Tom could look down upon a patchwork of
villages, farms, green pastures, yellow grain fields and stretches of
woodland. They were too far up to distinguish figures, but they could
see the white steam of rushing trains along the railroad tracks, and
even catch the sound of the engines' whistles.
Beyond glinted the blue of the sea flecked with sails and with here
and there a steamer's smoke smudging the horizon. Both lads were in
high spirits. It seemed good to be navigating the air again. Every now
and then inquisitive, high-flying crows would swoop toward the machine
and then dash off again with alarmed squawks.
Although they were making a high rate of speed, they hardly seemed to
be moving as they soared in long circles. To get a sense of rapid
motion, stationary objects must be in sight. In the lonely air it was
hard to tell that they were moving at all except by looking down at
the earth which, as they rose, appeared to be rushing from them, as if
it were sinking through space.
But novel as all these sensations would be to an aërial novice, they
were an old story to the boys. Jack devoted his attention to testing a
new steering appliance he had equipped the craft with, and Tom watched
his engines with an eagle eye to detect a skip or a "knock."
"How high now?" asked the young engineer after an interval.
Jack glanced at the barograph on the dashboard in front of him.
"Three thousand feet," he said.
"Might as well connect the alternator?" said Tom interrogatively.
Jack nodded, and Tom threw a lever which brought the generator of
high frequency currents in contact with the motor by means of a
friction fly-wheel. The alternator began to buzz and spark, crackling
viciously.
A sort of metal helmet with two receivers attached to it, one on each
side, lay handy at Jack's hand. In front of him was the transmitter
joined to the metal box which contained the microphone, transformers
and inductance tuning coil. Tuning in the aërial apparatus was
effected by means of a small knob projecting through a slit in the
metal box enclosing the delicate instruments including the detector.
By working this knob the tuning block was moved up and down the coil
till a proper "pitch" was obtained.
Jack experienced an odd thrill as he prepared to send the first spoken
word ever exchanged between an airship in motion and a station on
land. He and Tom had sent plenty of wireless messages while soaring
through the ether, but somehow, the dot and dash system had not half
the fascination and mystery of the possibility of exchanging coherent
speech between land and air.
He placed his lips close to the receiver, and with his hand on the
tuning knob sent forth a loud, clear hail:
"Hullo, High Towers!"
There was no answer for a few seconds while he patiently adjusted the
tuning knob. But then came a faint buzz like the humming of a drowsy
bee. Suddenly, sharp and distinct, as if his father was at his elbow,
came Mr. Chadwick's voice in reply:
"Hullo!"
"This is the Wondership. Three thousand feet in the air," cried Jack.
"Congratulations, my boy. It's a success so far."
"What shall we do now?" asked Jack.
"I want you to fly in the direction of Rayburn, and try to keep in
communication all the way."
"All right, dad," responded Jack, and altered the course of the
Wondership.
Rayburn was a small village some twenty-five miles to the north of
Nestorville. Jack kept the receivers on his ears as he flew along.
From time to time he exchanged conversation with his father. So far
everything appeared to be working as if there were no limit to the
distance over which the voices from the air and land could converse.
But suddenly there came a startling interruption to the experiments.
Jack felt a sharp "Bang" at his ears as if a small cannon had been
fired close at hand.