The information given to Herr Schwab by the Midfont station-master was
accurate up to a certain point. Mr. Greatorex had indeed constituted
himself the beneficent patron of Tom Dorrell, educated him, entertained
him at Midfont House, and built for him a workshop in the grounds. So
far the station-master was right. But when he added that Tom was working
at a new motor-car, he stated a hypothesis, not a fact.
About a year before this time, when Tom came to Midfont House to spend a
month's holiday, he brought with him a small model of an aerial machine
on which he had been quietly working in leisure moments. He showed it to
Mr. Greatorex.
"Very pretty," said the worthy merchant, examining the toy; "but it
won't _go_."
"Oh yes it will," said Tom. "See!"
They were in Mr. Greatorex's study at the time. Tom poised the model on
his left hand, released a spring, and the little aeroplane, with a whizz
and a hum, soared across the room, and, before it could be stopped,
dashed against the glass door of a bookcase and shivered it to atoms.
"I'm awfully sorry," said Tom contritely, picking up the machine and
silencing it.
"What _are_ you doing, John?" said Mrs. Greatorex, opening the door.
"What a terrible mess!" she added, surveying the litter on the floor.
"It shall be swept up, my dear," said Mr. Greatorex. "You can't make
omelets without breaking _eggs_, my love."
Mrs. Greatorex looked a little puzzled.
"Of course not, my dear," she said after a moment. Then with a
deprecating smile she went away. Mr. Greatorex locked the door.
"Now, Tom," he said, "just _explain_, will you? Begin at the beginning;
I want to _know_, you know."
"Well, I've been thinking a lot at odd times about airships and things,
and reading up what they've been doing in France and Germany. There's
little prospect of making a really serviceable machine out of the old
gas balloon; it's far too clumsy; can't make headway against a strong
wind; but I didn't see why something shouldn't be done on the lines of
the aeroplane. You see, it's easy enough to set the thing going, and
even to steer it, when you've got it up in the air; but there are three
difficulties: to get it up, to let it down without smashing it to bits,
and to keep it from turning somersaults. You can overcome the force of
gravity by an arrangement of planes when you keep up a good speed; but
if you slacken speed, down you come. And all the aeroplanes that have
been invented yet can't rise in the air at any given spot. They either
have to be thrown off from some elevated position, or they have to get
up a momentum along the ground, running like a motor-car. Then again,
the motor machinery has been too heavy; engines haven't been able to
exert sufficient horse-power in proportion to their own weight. I've
worked it out, and I calculate that no good can be done till you get an
engine that'll give you one horse-power to every two and a half pounds
of its weight."
"Yes. Well?"
"Well, this model is the result of no end of experiments. It goes, as
you see; but besides sailing horizontally, it will lift itself. Look!"
He took up the little machine, released another spring, and the
miniature airship went flying to the ceiling, where it remained until
the spring ran down.
"All very well," said Mr. Greatorex, unwilling to admit that he was
impressed; "but the thing is only a _toy_. There's all the difference in
the world between a model and the _real thing_, you know. You could
never get a spring strong enough to lift a real machine. I'm not
satisfied that you could even get the horizontal motion you're so
cocksure of, with a machine that would carry _men_."
"No spring would do it, it is true; but I've worked out an application
of the principle. It's well known that a propeller rotating at
sufficient speed can be made to lift a weight into the air. Of course we
couldn't set a real airship rotating bodily; no aeronaut's head would
stand it if we could. But, as you saw, my model doesn't rotate itself.
I've only made use of the principle--pretty successfully, don't you
think?"
"Just explain to me _thoroughly_, will you? I want a little more _light_
on the subject."
Tom took his model, and patiently expounded the mechanical principles on
which he had worked. The upshot of this and other conversations was that
Mr. Greatorex became first interested, then enthusiastic, and finally
determined. He had a workshop erected on a large piece of waste ground
nearly a mile and a half square on his estate, and gave Tom carte
blanche to get what assistance and spend what money he pleased.
Resolving to keep the matter a close secret until the experiments were
concluded, he fenced in the enclosure, and gave strict orders that no
one was to be admitted to it without Tom's consent. Tom himself devised
a simple means of defending the workshop from prying visitors. Whenever
he left it, he set going a strong electric current through the door
handle, which was a more effective protection than locks and bolts.
Tom found, as soon as he came to enlarge his model into a practical
working size, that none of the motors then on the market was
sufficiently powerful in proportion to its weight to give him the
necessary lifting force. The electric motor was out of the question, and
an adaptation of the latest petrol engine as applied to motor-cars and
launches seemed to offer the most likely solution. Even here, however,
the march of invention had not gone far enough. The latest petrol motor,
it is true, enabled Tom to keep the machine at a constant altitude when
once it was in flight; but it failed to raise it from a position of
rest. Some other method must be found, and he set his wits to work to
discover it.
The first condition of success was, he felt, the discovery of an
explosive mixture far more powerful than that offered by petrol, and yet
capable of being harnessed and controlled. He had the run of Mr.
Greatorex's chemical laboratories, and the benefit of the practical
advice and assistance of the heads of the experimental staff. Scores of
preparations were tried, and, for one reason or another, rejected. Where
sufficient power was obtained, it was almost invariably found that the
mixture was not stable or uniform in its effects. Several explosive
mixtures were discovered quite powerful enough for the purpose; but, as
Mr. Greatorex's chief chemist pointed out, all of them were likely to
blow the airship to smithereens in the event of any accident to the
machinery.
It was some months after the beginning of the experiments when one of
the junior chemists came to Tom with the announcement that he had
discovered what he thought might be the very substance required. A
German firm, Schlagintwert & Co. of Düsseldorf, had placed on the market
a few months earlier a powder which, used as a solution, was highly
valuable in preparing photographic plates. The exact ingredients of the
powder were unknown, although by analysis it had been found to consist
of nitrate compounds; but the buyer was warned by a label that it should
not be exposed to great heat owing to the danger of explosion. It had
occurred to the chemist to mix a little of this powder with petrol. The
result was a paste which dried hard, but gave off almost infinitesimal
particles of a highly explosive nature, when floating in an air chamber,
though the paste itself was not explosive either under heat or shock.
Tom was delighted with the discovery, and at once proceeded to construct
an engine suitable to the peculiar properties of the composition. In
building the motor he adapted the principle of the turbine to airship
navigation. A powerful fan drove the current of air through a number of
perforated aluminium plates covered with the paste. The resultant
mixture of air and explosive particles passed into the explosion
chamber, the intake being controlled by automatic valves connected with
the turbine. The explosion of the mixture was brought about by a
sparking plug connected with a small electric battery, the sparking
being controlled by a cam on the shaft. At each explosion, the gas
generated was forced at an enormous pressure through the turbine to the
right of the explosion chamber, thus driving the propeller fixed on the
shaft.
Tom made his fan serve a double purpose, not only to drive air through
the aluminium plates, but to send a current round a jacket on the
outside of the turbine and thus keep the latter cool. This was a highly
necessary arrangement owing to the enormous heat generated. From the
first, indeed, the difficulty of cooling the turbine was the most
serious with which he had to grapple. It required months of experiment
before the engine could be worked for more than two or three minutes at
a time. Gradually, however, by increasing the power of the fan, and
constructing the turbine casing and blades of an alloy specially adapted
to resist the effects of intense heat, this difficulty was to a great
extent overcome.
The airship when completed was not unlike a huge bird with wings
outstretched. The body of the bird consisted of the car and engine. The
wings were planes of lath strengthened with aluminium, and capable of
being inclined at any desired angle by the simple movement of a switch
in the car. A large rectangular plane projecting from the rear of the
car acted as a rudder, principally for lateral movement, motion upwards
and downwards being provided for either by the inclination of the larger
planes or by the special screws actuated by the engine. The latter drove
two sets of propellers: one fore and aft, giving a horizontal movement,
the other below and above the car, giving a vertical movement. Either
set of propellers could be thrown out of gear when desired. Tom would
have been glad to dispense with the vertical propellers if he could have
done so, but he found that the whole force of his engine was necessary
to raise the airship from a position of rest. He had not sufficient
motive power to enable him to use such an adjustment of oblique
propellers as would have ensured simultaneous horizontal and vertical
movement.
Mr. Greatorex at once promoted the fortunate young chemist who had
discovered the virtues of the Schlagintwert powder, and swore him to
secrecy. The parts of Tom's machine were made to his order by various
firms, the work being distributed so that no one firm should be in
possession of the complete apparatus; and a few weeks before Herr
Schwab's visit, an aeroplane capable of sustaining the weight of several
men was finished, and in it Tom made daily trips about the field. He
tested it so frequently that he used considerable quantities of the
powder, and it was not surprising that the curiosity of Schlagintwerts
was aroused by the large orders that came from one small place for an
article that cost a good deal more than its weight in gold.
Tom was, however, not yet satisfied with his machine. For one thing he
had found it impossible as yet to return to earth with any exactitude at
a fixed spot. It was a matter of the nice adjustment of the horizontal
with the vertical motion, and after repeated failures Tom comforted
himself with the thought that it must be only after long practice that
an engine driver could pull his locomotive up to a nicety. Obviously
much more practice must be required when the task was infinitely more
difficult.
Further, in spite of the jacket around the turbine, the heat generated
was still too great to allow of travelling any great distance in safety,
and the prospective usefulness of the aeroplane was discounted
accordingly.
It was Mr. Greatorex who suggested a possible way out of the difficulty.
"Why not have two engines instead of one?" he said. "If one breaks
down--why, there's the other."
"It means more weight," said Tom ruefully, "and therefore less speed and
less carrying capacity."
"Well, there's no _hurry_, is there? And as for carrying capacity--_I_
don't intend to tempt the fates, or run the risk of a smash-up like--who
was it? Icarus? Thought so."
Tom adopted the suggestion. He replaced his first engine by two somewhat
smaller, so that if one became overheated there was the other in
reserve. The lifting capacity and the speed of the airship were
consequently diminished, but scarcely so much as Tom expected.
So far the experiments had been carried on with perfect secrecy. The
enclosure was surrounded by trees, and Tom was always careful not to
drive his machine above the level of their tops. But one day, a few
months after Schwab's visit, he was careering round, to the mingled
admiration and terror of Timothy Ball watching him from the ground, when
he was startled by an exclamation that certainly did not spring from the
lips of that worthy. Timothy was a good quarter-mile away; the voice
appeared to come from a spot almost vertically below the aeroplane.
"By George! Look there, Mops!"
Tom took a hurried peep over. There, below him, in a gap between the
trees just beyond the inner fence, stood a tall young fellow in tennis
flannels, with light blue cap and tie.
"What is it, Pops?" answered a silvery voice; and a second figure joined
the first--a girl in white.
"Why, look! Hanged if it isn't an aeroplane, going like one o'clock,
too."
"Oh, how dreadful!" cried the girl, looking up. "I am sure it will fall,
and there will be a horrid accident. Oh, do come away, Raymond!"
"Not I! This is hot stuff, Mopsy. By Jove, the fellow can steer the
thing. He's making for that shanty over there--and coming down like a
lark. I say, Mops, give me a leg-up; I want to have a nearer squint at
the machine."
"But, Raymond, it's no business of yours--it's--it's trespassing!"
"Trespassing be hanged! We're next-door neighbours. Come, give me a
shove up."
He clutched the top of the fence; his sister, still feebly
expostulating, gave him a most workmanlike hoist, and in a few seconds
he disappeared on the other side. The girl waited a little; then turned
and walked away.
Her brother meanwhile was hastening across the field towards the
workshop, near which the aeroplane had by this time alighted. Halfway he
was met by Timothy Ball, who touched his cap and said--
"Beg pardon, sir, but these are private grounds and you're a
trespasser."
"That's all right. My name's Oliphant; we're neighbours of yours, you
know."
"Now, that's a good un. Hold hard, sir"--as the intruder made to walk
round him--"my orders is to allow no one on the premises! Your name's
Oliphant, you said? Well, you can't be a neighbour, 'cos the only
neighbour I knows of is Lord Langside."
"He's my father."
"But--Oliphant----"
"Exactly! Now, come along, my good fellow--I want to see your master."
"He don't want to see you, though. No you don't; keep off, sir; my
orders is to allow no one on the premises."
Then began a little game of dodging, Timothy stepping in front of the
intruder and stretching his arms like a cattle driver. In half a minute
Raymond Oliphant gave it up.
"Really, this is too absurd," he said good-temperedly. "I say, I'll give
you my word to stay here while you go and tell your master that I'd like
to introduce myself to him."
"Then you'll stay a long time, 'cos master's in town and won't be home
till seven o'clock."
"Well then, the driver of that aeroplane, whoever he is. Ah! here he
comes, thank goodness!"
Tom was hastening across the field. He wore his usual working suit of
blue alpaca; face and hands were much begrimed.
"Your watch-dog here won't let me pass," said Oliphant with a smile as
Tom came up. "I told him I was a neighbour, but he thinks I'm a bad lot.
We've only just come to the place; my father has taken it, you know;
he's coming down for shooting as soon as Parliament's up. I saw your
aeroplane skylarking round, and couldn't resist the temptation to come
over for a nearer look. You don't mind?"
"Well--no." Tom's tone was dubious.
"Oh, if you'd rather not, of course!"
"No, I don't mind really. But Mr. Greatorex is rather particular about
keeping the matter quiet----"
"I'll be mum as the dead, I assure you. I don't know anything about
machinery; it isn't in our line at Eton; you needn't be afraid of my
giving the secret away."
"It isn't that, exactly. I'm not afraid of your discovering the secret
of the machine; but it's rather important that the fact of its existence
shouldn't leak out just yet."
"Well, you'll have to make friends with my sister then. She has seen it
too. It's lucky Mother is in town, or the secret would be out by this
time."
They were walking now side by side to the shed.
"You're not Mr. Greatorex's son, then?"
"No; my name's Dorrell. I'm no relation of his."
"My name's Raymond Oliphant. I'm just home from Eton; long holidays, you
know. That's a clinking machine of yours. Never seen anything like it
before. Did Mr. Greatorex invent it? I understood he was a chemical
manufacturer."
"No. I did."
"Really! I say--d'you mind?--how old are you?"
"Eighteen."
"Just my age! And I'm rotting about at Eton while you----I say, you ought
to make a good thing of this."
"It's only experimental at present. We haven't tried a long flight."
"Will you get the Government to take it up? I'll put in a word with the
pater, you know."
"That's altogether premature," said Tom with a smile.
"Why, it seemed to me to go all right. Will it take two?"
"Two of our weight, I think. Would you like to try?"
"Rather! And I say, just keep out of sight from our grounds, will you?
If Margaret were to catch sight of me she'd have a fit or something. By
Jove! it won't be so slow here as I feared."
Oliphant spent a quarter of an hour in the air, and when he descended
was overflowing with enthusiasm.
"It's simply ripping, Mr. Dorrell," he cried. "I may come again, mayn't
I?"
"Certainly," said Tom, adding with a smile: "On one condition."
"Trust me, I won't say a word. And I'll shut Margaret's mouth too--if I
can. Look here, it seems to me you'd be the best man for that job. I'll
bring Margaret to-morrow--may I?--and when she knows you're the inventor,
and you impress on her that your life's at stake or something, she'll be
more likely to hold her tongue than if _I_ jaw. Good-bye."
Tom thought it necessary to inform Mr. Greatorex, in the drawing-room
before dinner, of what had happened.
"Hm!" he grunted. "Eton boy, is he? Got any _sense_?"
"I didn't examine him," said Tom with a laugh. "I thought him quite a
decent fellow. He was very good-tempered with Tim, who was a trifle
taken aback when he learnt that he had ordered off the son of the Prime
Minister."
"And a precious Prime Minister he _is_! Mark my words, Tom, the
Country's going to the dogs. To the _dogs_! We're dropping _behind_,
Tom, and Langside hasn't the grit to prevent it."
"Mr. Oliphant suggested that a word to his father might induce him to
buy the aeroplane for the Country."
"God bless my soul, you mustn't _dream_ of it! Langside will be turned
out at the next election; John Brooks will go in, and he's the man to
steer this old country through. No, no! and if young Oliphant blabs a
word of it to his father, I'll--I'll----Yes, my love"--as Mrs. Greatorex
entered--"we were talking about our new neighbour, Lord Langside. It
appears that his son and daughter have come down."
"Oh, John, do you think I should call?"
"On _no account_, my dear. I _hate_ Langside's politics, and we'll _have
nothing to do with them_. Now, Tom, give Mrs. Greatorex your arm."