Up and out into the night winged the great sea-and-air craft, the
powerful motors working without a skip, and the propellers beating the
air with a noise like the drone of a mastadonic bee--or more
appropriately, night beetle. Above shone the stars, steady points of
brightness in the dark blue canopy of heavens; below stretched the
silent, empty sea, heaving gently. The air was calm and still, and the
_Sea Eagle_ cleaved her way through it powerfully. Dr. Perkins set the
course at due southeast, and kept a careful eye on the compass.
"What speed are we making?" shouted Frank presently.
The inventor glanced at the aerial speed meter, a device of his own
invention.
"Close to fifty," he shouted back, for, owing to the roar of the engines
and propellers, it was necessary to raise the voice in speaking to any
one at a distance.
"Then we should be in the vicinity in half an hour?"
"Yes; that is unless----"
But Dr. Perkins broke off abruptly. The _Sea Eagle_ had now attained a
height of some five hundred feet, at which altitude he intended to keep
the craft till they reached the vicinity of the disabled yacht.
The cause of the sudden breaking off of his shouted remarks was this:
Without the slightest warning the _Sea Eagle_ gave a sickening dip
downward, and rushed toward the sea; or rather, to those in the falling
ship, it seemed as if the sea was racing up devouringly toward them.
"Gracious, what's happened?" shouted Harry.
But Frank was too busy with the engine to answer just then.
"Power! Give me lots of power!" yelled Dr. Perkins.
But although Frank instantly opened up the motor to its full capacity of
two thousand revolutions a minute, the downward rush still continued.
"The sea! We'll be plunged into the sea!" cried Harry, in alarm,
gripping a side support.
Indeed there appeared to be good cause for his apprehension, for the
_Sea Eagle_ was falling like a stone flung into space. All this, of
course, took place in far less time than it takes to describe or to read
it. In fact, hardly had Harry shouted his fears before the _Sea Eagle's_
"hull"--as we must call the hydroplane part of the craft--struck the
water, and a huge cloud of spray flew high on either side.
But instead of diving, the _Sea Eagle_ shot forward over the waves,
gliding over their tops for some time before Frank shut off the motor.
Even then such was the "shooting" velocity gained, that the _Sea Eagle_
still continued to scoot along until the young engineer, in response to
Dr. Perkins' instructions, reversed her propellers, and thus brought the
craft to a speedy standstill.
"What on earth happened?" demanded Frank anxiously, as the _Sea Eagle_
lay still, bobbing up and down on the gentle swell.
"We struck an air pocket. An empty hole in space where there was no
ether to support us," explained Dr. Perkins.
"Gracious; I thought we were goners," cried Harry, still a little shaky
over the fearful sensation of the fall.
"Had the _Sea Eagle_ been of different construction we should have dived
as straight to the bottom as a loon," said the inventor, "but the
spoonlike construction of the bow allowed me to handle her so that,
instead of the impulse of the fall being downward, it was diverted into
a forward movement along the surface."
"Shall we go up again?" asked Frank, after a hasty examination had been
made to ascertain if anything had parted or snapped under the strain of
the suddenly arrested tumble through the air pocket.
"Yes. We had better lose as little time as possible," was the rejoinder.
"If you are ready, start the engine up, and we will try a flight from
the surface of the water."
"You want full power?" asked Frank.
"Yes; but start up gently at first, gradually increasing to top
velocity. I think, however, that we shall leave the water at about 1,500
revolutions a minute."
The next minute the roar of the newly started engine prevented further
conversation. In order to develop every ounce of power of which the
motor was capable Frank had opened the muffler cut-out, and the uproar
was terrific. Spurts of greenish flame spouted from the exhausts, and
the acrid smell of burning oil and gasolene filled the air. To any one
less accustomed than the Boy Aviators to the uproar of aerial motors,
the noise would have been alarming to say the least. They, however, were
too much used to such scenes to pay any attention to it.
Faster and faster the _Sea Eagle_ sped over the waves, till her keel
barely touched the tips of the swells. Then suddenly the jerky motion
ceased, and the craft, buoyed by its wings, began to soar upward in a
steadily increasing gradient. Before ten minutes had passed they were
once more on an even keel at a five-hundred-feet altitude, and bearing
steadily for the southwest.
Frank looked at his watch.
"We ought to be getting pretty close to that yacht by now," he remarked
to Harry, who had seated himself at his side, and was assisting in
attending to the lubrication and watching of the motor.
"I'll keep a sharp lookout," rejoined Harry; "they surely ought to hear
the noise of our motor and send up a rocket or wave lights, or
something, if they are in the vicinity.
"That's just what I think. Keep your eyes open while I watch the
engine."
Harry peered out into the night, but as far as he could see nothing
appeared but the reflection of the stars in the water to relieve its
blackness.
"I can't see anything yet," he said, after a while.
"Just keep on looking," rejoined Frank; "there's a chance that they may
have drifted from the position they gave us."
"Well, in any case it would have been impossible for us to fly direct to
the spot," rejoined Harry; "this thing is a good deal like looking for a
needle in a haystack, to my way of thinking."
"I'm not so sure of that. If they are anywhere within five or six miles
they must hear the beat of our motor."
"Wonder why Dr. Perkins doesn't switch on the searchlight. Hullo, there
it goes now."
As Harry spoke, a fan-shaped ray of brilliant white light cut the night
in front of the _Sea Eagle_, like a radiant sword. Hither and thither it
swept over the dark sea; but it revealed nothing. All at once Dr.
Perkins shut the searchlight off.
"If they have seen it they will reply in some way," he shouted in
explanation to the boys. "Keep a bright lookout for an answer. I'll keep
the _Sea Eagle_ swinging in circles. We have been doing thirty miles an
hour, and even allowing for the delay when we struck the air pocket we
ought to be in the disabled yacht's vicinity by this time."
As the searchlight was extinguished Harry peered out into the darkness
with straining eyes. Suddenly he gave a shout and clutched Frank's arm.
"What's that," he shouted, "that light off there to the south?"
"It's a lantern," cried Frank; "somebody's waving it."
Dr. Perkins confirmed Frank's supposition, and the _Sea Eagle_, on her
errand of rescue, was headed for the swinging pin-point of light in the
distance.