CHAPTER II
THE FLYING MERMAID
"Here! Stop him!" cried Professor Henderson. "Don't let him get away. Westill 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 impededbecause he kept looking back as if he feared the new ship was chasinghim.
"Come on back!" said Mark. "There's no danger, and if there was we'renot going to start to-day."
"Ain't yo' foolin' me?" asked Washington, pausing and looking doubtfullyat the boys.
"Of course not," answered Mark. "You know Professor Henderson would notmake you do anything you didn't want to do, Wash. He wishes you to stayand help him get ready, that's all."
"Well, Washington," observed the aged scientist. "I didn't think you'dgo back on me."
"I'd do mos' anything fer yo', Perfesser," said the colored man, "but Igot t' beg off this time," and he looked at the _Flying Mermaid_ as ifhe thought the metal sides would open and devour him.
"Then help me get things in shape to generate the gas," the scientistsaid. "I want to give the new vapor the first real test in lifting powerto-day. On the success of it depends the future of the ship."
Seeing there was no immediate danger of being carried to the centre ofthe earth, Washington resumed his labors. The professor, the boys, Billand Tom were also hurrying matters to enable a test to be made beforenight.
As will readily be seen, even by those not familiar with theconstruction of airships and submarines, the chief problem was to findsome agent strong enough to lift from the earth a weight heavier thanhad ever before been put into an apparatus that was destined to traversethe clouds. For the _Flying Mermaid_ was not only an airship but anocean voyager as well. It had to be made light enough to be lifted farabove the earth, yet the very nature of it, necessitating it being madeheavy enough to stand the buffeting of the waves and the pressure ofwater, was against its flying abilities.
Professor Henderson realized this and knew that the chief concern wouldbe to discover a gas or vapor with five times the lifting power ofhydrogen, one of the lightest gases known, and one sometimes used toinflate balloons.
After long study he had been partially successful, but he knew fromexperiments made that the gas he had so far been able to manufacturewould not answer. What he wanted was some element that could be mixedwith the gas, to neutralize the attraction of gravitation, or downwardpull of the earth.
While he was seeking this, and experimenting on many lines, theconstruction of the air-water ship went on. In general the outwardconstruction was two cigar shaped hulls, one above the other. Aluminum,being the lightest and strongest metal that could be used for thepurpose, formed the main part of both bodies.
The upper hull was one hundred feet long and twenty feet in diameter atthe widest part. It tapered to points at either end. It was attached tothe lower hull by strong braces, at either end, while from the centerthere extended a pipe which connected with the lower section. This pipewas intended to convey the lifting gas to the part which corresponded tothe bag of the balloon, save that it was of metal instead of silk, orrubber as is usual.
There were two reasons for this. One was that it would not be liable topuncture, particularly in the proposed underground trip, and the otherwas that it did not have to be so large as a cloth bag would have had tobe. It was also a permanent part of the ship, and on a voyage where partof the time the travelers would be in the air and part on the water, andwhen 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 inthe 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 feetlong, and forty feet through at the largest part, in the centre.
It was divided into four sections. The forward one contained thesleeping quarters of Professor Henderson and his crew. There was a smallstateroom for each one. Above was a conning or observation tower,reached by a small flight of steps. From this tower the ship could besteered, stopped and started, as could also be done from the engineroom, which was in the after part of the hull.
As in the _Porpoise_ and _Monarch_, electricity formed the motive powerand was also used for many other purposes on board. Engines operated bygas produced the current which heated, lighted and moved the ship, aswell as played a part in producing the wonderful gas.
The ship moved forward or backward by means of a novel arrangement. Thiswas by the power of compressed air. From either end of the lower hullthere projected a short pipe working in a ball and socket joint, so itcould be turned in any direction. By means of strong pumps a current ofcompressed air could be sent out from either pipe. Thus when floatingabove the earth the ship was forced forward by the blast of air rushingfrom the pipe at the stern. It was the same principle as that on which asky rocket is shot heavenward, save that gases produced by the burningof powder in the pasteboard rocket form its moving impulse.
In the case of the _Flying Mermaid_, it could be made to move backwardby sending the air out of the forward tube. Thus, when in the water, thecompressed air rushing from the pipe struck the fluid and forced theship forward or backward as was desired. It floated on the surface, thedeck being about three feet out of water, while the aluminum gas bag wasoverhead.
The engine room was a marvel of machine construction. It contained pumpsfor air and water, motors, dynamos, gas engines, and a maze of wheelsand 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 alarge propellor such as most airships have to use, a propellor whichmust of necessity be very light and which is easily broken.
Next to the engine room was the kitchen. It contained an electric rangeand all necessary appliances and utensils for preparing meals. Therewere lockers and a large reserve storeroom which when the time camewould be well stocked with food. Forward of the kitchen was the livingand dining room. It contained comfortable seats, folding tables and asmall library. Here, also were many instruments designed to show how thevarious machines were working. There were gages, pointers and dials,which told the direction the ship was traveling, the speed and thedistance above the earth or below the surface. Similar indicators werein the conning tower, which had a powerful search light.
The ship was lighted throughout by incandescent lamps, and there waseven a small automatic piano worked by the electric current, on whichpopular airs could be played.
If the gas and the gravity neutralizer worked as Professor Hendersonhoped they would, as soon as the ship was completed, all that would benecessary to start on the voyage would be to fill the aluminum bag andset the air compressor in motion.
The gas was made from common air, chemically treated and with a secretmaterial added which by means of a complicated machine in a measure didaway with the downward pull of the earth. Thus all that was necessary tocarry on a long voyage was a quantity of gasolene to operate the enginewhich worked the electric machines, and some of this secret compound.
The professor and his helpers had been working to good advantage. Atlast all was in readiness for the gas test.
It was proposed to try it on an experimental scale. Some of the fluidwas to be generated and forced into an aluminum cylinder under the samepressure it would be used in the air ship. To this cylinder wereattached 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 theship," said the professor. "I am going to fasten to it a hundred poundweight. If it lifts that our latest contrivance will be a success."
"You mean if the little cylinder pulls a hundred pounds up the big shipwill take us and the machinery up?" asked Mark.
"Certainly," answered the professor. "If this cylinder lifts a hundredpounds, one a hundred times as bi
g (as that of the _Mermaid_ is), willlift 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 andcontents. The latest war balloon can lift one ton with ease, and if mymachine can not do five times as well I shall be disappointed."
The last adjustments were made, pipes were run from the gas generator tothe cylinder, and the hundred pound weight was attached.
"Everybody look out now," said Mr. Henderson. "I am going to start themachine and let the gas enter the cylinder. It is a very powerful gasand may break the cylinder. If it does you must all duck."
The scientist gave a last look at everything. The boys got behind someboards whence they could see without being in danger. Washington, whohad 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, stationedthemselves in safe places.
"All ready!" called the professor.
He pulled a lever toward him, turned a wheel and signalled to Washingtonto start the dynamo. There was a sound of buzzing machinery, which wasfollowed by a hiss as the gas began to enter the cylinder underpressure. Would it stand the strain? That question was uppermost inevery one's mind save the professor's. He only cared to see the cylinderleave the ground, carrying the weight with it. That would prove his longlabors were crowned with success.
Faster and faster whirred the dynamo. The gas was being generated fromthe air. The secret chemical made a hissing which could be heard forsome distance. The gage registered a heavy pressure. Anxiously theprofessor watched the cylinder.
"There!" he exclaimed at length. "It has all the gas it can hold. Now tosee if it works!"
He disconnected the pipe leading from the generator. This left thecylinder free. It seemed to tremble slightly. There appeared to be amovement to the hundred pound weight which rested on the ground. It wasas 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, comingfrom the dynamo.
Sure enough the cylinder was slowly rising in the air, bearing theweight with it. It had lifted it clear from the ground and wasapproaching the roof of the big shed.
"It will work! It will work!" exclaimed the professor, strangelyexcited.
The next instant the cylinder, carrying the weight, sailed right out ofan open skylight, and began drifting outside the shop, and across thefields.
"Quick! We must get it back!" cried Mr. Henderson. "If it gets away mysecret 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 tothe east, the weight dangling below it, making it look like a miniatureairship.
"We can never catch that!" cried Mark.