THE FLYING MERMAID
"Here! Stop him!" cried Professor Henderson. "Don't let him get away. We
still need his help to get the ship in shape. He needn't be frightened.
We're not going to start at once."
Mark and Jack ran after Washington, whose progress was somewhat impeded
because he kept looking back as if he feared the new ship was chasing
him.
"Come on back!" said Mark. "There's no danger, and if there was we're
not going to start to-day."
"Ain't yo' foolin' me?" asked Washington, pausing and looking doubtfully
at the boys.
"Of course not," answered Mark. "You know Professor Henderson would not
make you do anything you didn't want to do, Wash. He wishes you to stay
and help him get ready, that's all."
"Well, Washington," observed the aged scientist. "I didn't think you'd
go back on me."
"I'd do mos' anything fer yo', Perfesser," said the colored man, "but I
got t' beg off this time," and he looked at the _Flying Mermaid_ as if
he thought the metal sides would open and devour him.
"Then help me get things in shape to generate the gas," the scientist
said. "I want to give the new vapor the first real test in lifting power
to-day. On the success of it depends the future of the ship."
Seeing there was no immediate danger of being carried to the centre of
the earth, Washington resumed his labors. The professor, the boys, Bill
and Tom were also hurrying matters to enable a test to be made before
night.
As will readily be seen, even by those not familiar with the
construction of airships and submarines, the chief problem was to find
some agent strong enough to lift from the earth a weight heavier than
had ever before been put into an apparatus that was destined to traverse
the clouds. For the _Flying Mermaid_ was not only an airship but an
ocean voyager as well. It had to be made light enough to be lifted far
above the earth, yet the very nature of it, necessitating it being made
heavy enough to stand the buffeting of the waves and the pressure of
water, was against its flying abilities.
Professor Henderson realized this and knew that the chief concern would
be to discover a gas or vapor with five times the lifting power of
hydrogen, one of the lightest gases known, and one sometimes used to
inflate balloons.
After long study he had been partially successful, but he knew from
experiments made that the gas he had so far been able to manufacture
would not answer. What he wanted was some element that could be mixed
with the gas, to neutralize the attraction of gravitation, or downward
pull of the earth.
While he was seeking this, and experimenting on many lines, the
construction of the air-water ship went on. In general the outward
construction was two cigar shaped hulls, one above the other. Aluminum,
being the lightest and strongest metal that could be used for the
purpose, formed the main part of both bodies.
The upper hull was one hundred feet long and twenty feet in diameter at
the widest part. It tapered to points at either end. It was attached to
the lower hull by strong braces, at either end, while from the center
there extended a pipe which connected with the lower section. This pipe
was intended to convey the lifting gas to the part which corresponded to
the bag of the balloon, save that it was of metal instead of silk, or
rubber as is usual.
There were two reasons for this. One was that it would not be liable to
puncture, particularly in the proposed underground trip, and the other
was that it did not have to be so large as a cloth bag would have had to
be. It was also a permanent part of the ship, and on a voyage where part
of the time the travelers would be in the air and part on the water, and
when the change from one to the other would have to be made quickly,
this was necessary. It would have taken too long to raise the ship in
the air had a cloth bag been used to contain the gas.
The lower hull or main part of the craft was one hundred and fifty feet
long, and forty feet through at the largest part, in the centre.
It was divided into four sections. The forward one contained the
sleeping quarters of Professor Henderson and his crew. There was a small
stateroom for each one. Above was a conning or observation tower,
reached by a small flight of steps. From this tower the ship could be
steered, stopped and started, as could also be done from the engine
room, which was in the after part of the hull.
As in the _Porpoise_ and _Monarch_, electricity formed the motive power
and was also used for many other purposes on board. Engines operated by
gas produced the current which heated, lighted and moved the ship, as
well as played a part in producing the wonderful gas.
The ship moved forward or backward by means of a novel arrangement. This
was by the power of compressed air. From either end of the lower hull
there projected a short pipe working in a ball and socket joint, so it
could be turned in any direction. By means of strong pumps a current of
compressed air could be sent out from either pipe. Thus when floating
above the earth the ship was forced forward by the blast of air rushing
from the pipe at the stern. It was the same principle as that on which a
sky rocket is shot heavenward, save that gases produced by the burning
of powder in the pasteboard rocket form its moving impulse.
In the case of the _Flying Mermaid_, it could be made to move backward
by sending the air out of the forward tube. Thus, when in the water, the
compressed air rushing from the pipe struck the fluid and forced the
ship forward or backward as was desired. It floated on the surface, the
deck being about three feet out of water, while the aluminum gas bag was
overhead.
The engine room was a marvel of machine construction. It contained pumps
for air and water, motors, dynamos, gas engines, and a maze of wheels
and levers. Yet everything was very compact and no room was wasted.
The use of the air method of propulsion did away with the necessity of a
large propellor such as most airships have to use, a propellor which
must of necessity be very light and which is easily broken.
Next to the engine room was the kitchen. It contained an electric range
and all necessary appliances and utensils for preparing meals. There
were lockers and a large reserve storeroom which when the time came
would be well stocked with food. Forward of the kitchen was the living
and dining room. It contained comfortable seats, folding tables and a
small library. Here, also were many instruments designed to show how the
various machines were working. There were gages, pointers and dials,
which told the direction the ship was traveling, the speed and the
distance above the earth or below the surface. Similar indicators were
in the conning tower, which had a powerful search light.
The ship was lighted throughout by incandescent lamps, and there was
even a small automatic piano worked by the electric current, on which
popular airs could be played.
If the gas and the gravity neutralizer worked as Professor Henderson
hoped they would, as soon as the ship was completed, all that would be
necessary to start on the voyage would be to fill the aluminum bag and
set the air compressor in motion.
The gas was made from common air, chemically treated and with a secret
material added which by means of a complicated machine in a measure did
away with the downward pull of the earth. Thus all that was necessary to
carry on a long voyage was a quantity of gasolene to operate the engine
which worked the electric machines, and some of this secret compound.
The professor and his helpers had been working to good advantage. At
last all was in readiness for the gas test.
It was proposed to try it on an experimental scale. Some of the fluid
was to be generated and forced into an aluminum cylinder under the same
pressure it would be used in the air ship. To this cylinder were
attached weights in proportion to the weight of the _Flying Mermaid_
with its load of human freight, engines and equipment.
"This cylinder is just one one-hundredth the size of the cylinder of the
ship," said the professor. "I am going to fasten to it a hundred pound
weight. If it lifts that our latest contrivance will be a success."
"You mean if the little cylinder pulls a hundred pounds up the big ship
will take us and the machinery up?" asked Mark.
"Certainly," answered the professor. "If this cylinder lifts a hundred
pounds, one a hundred times as big (as that of the _Mermaid_ is), will
lift a hundred times as much, or ten thousand pounds. That is five tons,
or more than a ton over what I figure to be the weight of our ship and
contents. The latest war balloon can lift one ton with ease, and if my
machine can not do five times as well I shall be disappointed."
The last adjustments were made, pipes were run from the gas generator to
the cylinder, and the hundred pound weight was attached.
"Everybody look out now," said Mr. Henderson. "I am going to start the
machine and let the gas enter the cylinder. It is a very powerful gas
and may break the cylinder. If it does you must all duck."
The scientist gave a last look at everything. The boys got behind some
boards whence they could see without being in danger. Washington, who
had little fear so long as there was no danger of going under ground,
took his place at the dynamo. Andy Sudds, with Bill and Tom, stationed
themselves in safe places.
"All ready!" called the professor.
He pulled a lever toward him, turned a wheel and signalled to Washington
to start the dynamo. There was a sound of buzzing machinery, which was
followed by a hiss as the gas began to enter the cylinder under
pressure. Would it stand the strain? That question was uppermost in
every one's mind save the professor's. He only cared to see the cylinder
leave the ground, carrying the weight with it. That would prove his long
labors were crowned with success.
Faster and faster whirred the dynamo. The gas was being generated from
the air. The secret chemical made a hissing which could be heard for
some distance. The gage registered a heavy pressure. Anxiously the
professor watched the cylinder.
"There!" he exclaimed at length. "It has all the gas it can hold. Now to
see if it works!"
He disconnected the pipe leading from the generator. This left the
cylinder free. It seemed to tremble slightly. There appeared to be a
movement to the hundred pound weight which rested on the ground. It was
as if it was tugging to get loose.
"There it goes! There it goes!" cried Mark, joyfully.
"Hurrah!" shouted Jack. "There she rises!"
"It suttinly am projectin' itself skyward!" yelled Washington, coming
from the dynamo.
Sure enough the cylinder was slowly rising in the air, bearing the
weight with it. It had lifted it clear from the ground and was
approaching the roof of the big shed.
"It will work! It will work!" exclaimed the professor, strangely
excited.
The next instant the cylinder, carrying the weight, sailed right out of
an open skylight, and began drifting outside the shop, and across the
fields.
"Quick! We must get it back!" cried Mr. Henderson. "If it gets away my
secret may be discovered and I will lose all! We must secure it!"
But the cylinder was now two hundred feet in the air and being blown to
the east, the weight dangling below it, making it look like a miniature
airship.
"We can never catch that!" cried Mark.