engine is trivial, and the space in which you can exercise it, limited.
Now suppose two stations, A and B, two miles distant by the track.
Imagine a train of platform cars, the last car resting at station A. The
train is a mile long, say. The engine is therefore within a mile of
station B. Say the train can move a mile in ten minutes. The last car,
having two miles to go, would reach B in twenty minutes, but the engine,
a mile ahead, would get there in ten. You jump on the last car, at A, in
a prodigious hurry to reach Abscissa, who is at B. If you stay on the
last car it will be twenty long minutes before you see her. But the
engine reaches B and the fair lady in ten. You will be a stupid
reasoner, and an indifferent lover, if you don't put for the engine over
those platform cars, as fast as your legs will carry you. You can run a
mile, the length of the train, in ten minutes. Therefore, you reach
Abscissa when the engine does, or in ten minutes--ten minutes sooner
than if you had lazily sat down upon the rear car and talked politics
with the brakeman. You have diminished the time by one half. You have
added your speed to that of the locomotive to some purpose. _Nicht
wahr?_"
I saw it perfectly; much plainer, perhaps, for his putting in the clause
about Abscissa.
He continued:
"This illustration, though a slow one, leads up to a principle which may
be carried to any extent. Our first anxiety will be to spare your legs
and wind. Let us suppose that the two miles of track are perfectly
straight, and make our train one platform car, a mile long, with
parallel rails laid upon its top. Put a little dummy engine on these
rails, and let it run to and fro along the platform car, while the
platform car is pulled along the ground track. Catch the idea? The dummy
takes your place. But it can run its mile much faster. Fancy that our
locomotive is strong enough to pull the platform car over the two miles
in two minutes. The dummy can attain the same speed. When the engine
reaches B in one minute, the dummy, having gone a mile a-top the
platform car, reaches B also. We have so combined the speeds of those
two engines as to accomplish two miles in one minute. Is this all we can
do? Prepare to exercise your imagination."
I lit my pipe.
"Still two miles of straight track, between A and B. On the track a long
platform car, reaching from A to within a quarter of a mile of B. We
will now discard ordinary locomotives and adopt as our motive power a
series of compact magnetic engines, distributed underneath the platform
car, all along its length."
"I don't understand those magnetic engines."
"Well, each of them consists of a great iron horseshoe, rendered
alternately a magnet and not a magnet by an intermittent current of
electricity from a battery, this current in its turn regulated by
clock-work. When the horseshoe is in the circuit, it is a magnet, and it
pulls its clapper toward it with enormous power. When it is out of the
circuit, the next second, it is not a magnet, and it lets the clapper
go. The clapper, oscillating to and fro, imparts a rotatory motion to a
fly-wheel, which transmits it to the drivers on the rails. Such are our
motors. They are no novelty, for trial has proved them practicable.
"With a magnetic engine for every truck of wheels, we can reasonably
expect to move our immense car, and to drive it along at a speed, say,
of a mile a minute.
"The forward end, having but a quarter of a mile to go, will reach B in
fifteen seconds. We will call this platform car number 1. On top of
number 1 are laid rails on which another platform car, number 2, a
quarter of a mile shorter than number 1, is moved in precisely the same
way. Number 2, in its turn, is surmounted by number 3, moving
independently of the tiers beneath, and a quarter of a mile shorter than
number 2. Number 2 is a mile and a half long; number 3 a mile and a
quarter. Above, on successive levels, are number 4, a mile long; number
5, three quarters of a mile; number 6, half a mile; number 7, a quarter
of a mile, and number 8, a short passenger car, on top of all.
"Each car moves upon the car beneath it, independently of all the
others, at the rate of a mile a minute. Each car has its own magnetic
engines. Well, the train being drawn up with the latter end of each car
resting against a lofty bumping-post at A, Tom Furnace, the gentlemanly
conductor, and Jean Marie Rivarol, engineer, mount by a long ladder to
the exalted number 8. The complicated mechanism is set in motion. What
happens?
"Number 8 runs a quarter of a mile in fifteen seconds and reaches the
end of number 7. Meanwhile number 7 has run a quarter of a mile in the
same time and reached the end of number 6; number 6, a quarter of a mile
in fifteen seconds, and reached the end of number 5; number 5, the end
of number 4; number 4, of number 3; number 3, of number 2; number 2, of
number 1. And number 1, in fifteen seconds, has gone its quarter of a
mile along the ground track, and has reached station B. All this has
been done in fifteen seconds. Wherefore, numbers 1, 2, 3, 4, 5, 6, 7,
and 8 come to rest against the bumping-post at B, at precisely the same
second. We, in number 8, reach B just when number 1 reaches it. In other
words, we accomplish two miles in fifteen seconds. Each of the eight
cars, moving at the rate of a mile a minute, has contributed a quarter
of a mile to our journey, and has done its work in fifteen seconds. All
the eight did their work at once, during the same fifteen seconds.
Consequently we have been whizzed through the air at the somewhat
startling speed of seven and a half seconds to the mile. This is the
Tachypomp. Does it justify the name?"
Although a little bewildered by the complexity of cars, I apprehended
the general principle of the machine. I made a diagram, and understood
it much better. "You have merely improved on the idea of my moving
faster than the train when I was going to the smoking car?"
"Precisely. So far we have kept within the bounds of the practicable. To
satisfy the Professor, you can theorize in something after this fashion:
If we double the number of cars, thus decreasing by one half the
distance which each has to go, we shall attain twice the speed. Each of
the sixteen cars will have but one eighth of a mile to go. At the
uniform rate we have adopted, the two miles can be done in seven and a
half instead of fifteen seconds. With thirty-two cars, and a sixteenth
of a mile, or twenty rods difference in their length, we arrive at the
speed of a mile in less than two seconds; with sixty-four cars, each
travelling but ten rods, a mile under the second. More than sixty miles
a minute! If this isn't rapid enough for the Professor, tell him to go
on, increasing the number of his cars and diminishing the distance each
one has to run. If sixty-four cars yield a speed of a mile inside the
second, let him fancy a Tachypomp of six hundred and forty cars, and
amuse himself calculating the rate of car number 640. Just whisper to
him that when he has an infinite number of cars with an infinitesimal
difference in their lengths, he will have obtained that infinite speed
for which he seems to yearn. Then demand Abscissa."
I wrung my friend's hand in silent and grateful admiration. I could say
nothing.
"You have listened to the man of theory," he said proudly. "You shall
now behold the practical engineer. We will go to the west of the
Mississippi and find some suitably level locality. We will erect thereon
a model Tachypomp. We will summon thereunto the professor, his daughter,
and why not his fair sister Jocasta, as well? We will take them a
journey which shall much astonish the venerable Surd. He shall place
Abscissa's digits in yours and bless you both with an algebraic formula.
Jocasta shall contemplate with wonder the genius of Rivarol. But we have
much to do. We must ship to St. Joseph the vast amount of material to
be employed in the construction of the Tachypomp. We must engage a small
army of workmen to effect that construction, for we are to annihilate
time and space. Perhaps you had better see your bankers."
I rushed impetuously to the door. There should be no delay.
"Stop! stop! _Um Gottes Willen_, stop!" shrieked Rivarol. "I launched my
butcher this morning and I haven't bolted the----"
But it was too late. I was upon the trap. It swung open with a crash,
and I was plunged down, down, down! I felt as if I were falling through
illimitable space. I remember wondering, as I rushed through the
darkness, whether I should reach Kerguellen's Land or stop at the
centre. It seemed an eternity. Then my course was suddenly and painfully
arrested.
I opened my eyes. Around me were the walls of Professor Surd's study.
Under me was a hard, unyielding plane which I knew too well was
Professor Surd's study floor. Behind me was the black, slippery,
hair-cloth chair which had belched me forth, much as the whale served
Jonah. In front of me stood Professor Surd himself, looking down with a
not unpleasant smile.
"Good-evening, Mr. Furnace. Let me help you up. You look tired, sir. No
wonder you fell asleep when I kept you so long waiting. Shall I get you
a glass of wine? No? By the way, since receiving your letter I find
that you are a son of my old friend, Judge Furnace. I have made
inquiries, and see no reason why you should not make Abscissa a good
husband."
Still I can see no reason why the Tachypomp should not have succeeded.
Can you?
[5] _Scribner's Monthly, March, 1874._
End of Project Gutenberg's Stories by American Authors, Volume 5, by Various