Well, then, the room is the heavens, the table is the
earth, and you are the moon!"
And they go away delighted with the comparison.
Thus, then, the moon always presents the same face to the earth; still,
to be quite exact, it should be added that in consequence of certain
fluctuations from north to south and from west to east, called
libration, she shows rather more than the half of her disc, about 0.57.
When the ignoramuses knew as much as the director of the Cambridge
Observatory about the moon's movement of rotation they began to make
themselves uneasy about her movement of revolution round the earth, and
twenty scientific reviews quickly gave them the information they wanted.
They then learnt that the firmament, with its infinite stars, may be
looked upon as a vast dial upon which the moon moves, indicating the
time to all the inhabitants of the earth; that it is in this movement
that the Queen of Night shows herself in her different phases, that she
is full when she is in opposition with the sun—that is to say, when the
three bodies are on a line with each other, the earth being in the
centre; that the moon is new when she is in conjunction with the
sun—that is to say, when she is between the sun and the earth; lastly,
that the moon is in her first or last quarter when she makes, with the
sun and the earth, a right angle of which she occupies the apex.
Some perspicacious Yankees inferred in consequence that eclipses could
only take place at the periods of conjunction or opposition, and their
reasoning was just. In conjunction the moon can eclipse the sun, whilst
in opposition it is the earth that can eclipse him in her turn; and the
reason these eclipses do not happen twice in a lunar month is because
the plane upon which the moon moves is elliptical like that of the
earth.
As to the height which the Queen of Night can attain above the horizon,
the letter from the Observatory of Cambridge contained all that can be
said about it. Every one knew that this height varies according to the
latitude of the place where the observation is taken. But the only zones
of the globe where the moon reaches her zenith—that is to say, where
she is directly above the heads of the spectators—are necessarily
comprised between the 28th parallels and the equator. Hence the
important recommendation given to attempt the experiment upon some point
in this part of the globe, in order that the projectile may be hurled
perpendicularly, and may thus more quickly escape the attraction of
gravitation. This was a condition essential to the success of the
enterprise, and public opinion was much exercised thereupon.
As to the line followed by the moon in her revolution round the earth,
the Observatory of Cambridge had demonstrated to the most ignorant that
it is an ellipse of which the earth occupies one of the foci. These
elliptical orbits are common to all the planets as well as to all the
satellites, and rational mechanism rigorously proves that it could not
be otherwise. It was clearly understood that when at her apogee the moon
was farthest from the earth, and when at her perigee she was nearest to
our planet.
This, therefore, was what every American knew whether he wished to or
no, and what no one could decently be ignorant of. But if these true
principles rapidly made their way, certain illusive fears and many
errors were with difficulty cleared away.
Some worthy people maintained, for instance, that the moon was an
ancient comet, which, whilst travelling along its elongated orbit round
the sun, passed near to the earth, and was retained in her circle of
attraction. The drawing-room astronomers pretended to explain thus the
burnt aspect of the moon, a misfortune of which they accused the sun.
Only when they were told to notice that comets have an atmosphere, and
that the moon has little or none, they did not know what to answer.
Others belonging to the class of "Shakers" manifested certain fears
about the moon; they had heard that since the observations made in the
times of the Caliphs her movement of revolution had accelerated in a
certain proportion; they thence very logically concluded that an
acceleration of movement must correspond to a diminution in the distance
between the two bodies, and that this double effect going on infinitely
the moon would one day end by falling into the earth. However, they were
obliged to reassure themselves and cease to fear for future generations
when they were told that according to the calculations of Laplace, an
illustrious French mathematician, this acceleration of movement was
restricted within very narrow limits, and that a proportional diminution
will follow it. Thus the equilibrium of the solar world cannot be
disturbed in future centuries.
Lastly there was the superstitious class of ignoramuses to be dealt
with; these are not content with being ignorant; they know what does not
exist, and about the moon they know a great deal. Some of them
considered her disc to be a polished mirror by means of which people
might see themselves from different points on the earth, and communicate
their thoughts to one another. Others pretended that out of 1,000 new
moons 950 had brought some notable change, such as cataclysms,
revolutions, earthquakes, deluges, &c.; they therefore believed in the
mysterious influence of the Queen of Night on human destinies; they
think that every Selenite is connected by some sympathetic tie with each
inhabitant of the earth; they pretend, with Dr. Mead, that she entirely
governs the vital system—that boys are born during the new moon and
girls during her last quarter, &c., &c. But at last it became necessary
to give up these vulgar errors, to come back to truth; and if the moon,
stripped of her influence, lost her prestige in the minds of courtesans
of every power, if some turned their backs on her, the immense majority
were in her favour. As to the Yankees, they had no other ambition than
that of taking possession of this new continent of the sky, and to plant
upon its highest summit the star-spangled banner of the United States of
America.
*
The Cambridge Observatory had, in its memorable letter of October 7th,
treated the question from an astronomical point of view—the mechanical
point had still to be treated. It was then that the practical
difficulties would have seemed insurmountable to any other country but
America; but there they were looked upon as play.
President Barbicane had, without losing any time, nominated a working
committee in the heart of the Gun Club. This committee was in three
sittings to elucidate the three great questions of the cannon, the
projectile, and the powder. It was composed of four members very learned
upon these matters. Barbicane had the casting vote, and with him were
associated General Morgan, Major Elphinstone, and, lastly, the
inevitable J.T. Maston, to whom were confided the functions of
secretary.
On the 8th of October the committee met at President Barbicane's house,
No. 3, Republican-street; as it was important that the stomach should
not trouble so important a debate, the four members of the Gun Club took
their seats at a table covered with sandwiches and teapots. J.T. Maston
immediately screwed his pen on to his steel hook and the business began.
Barbicane opened the meeting as follows:—
"Dear colleagues," said he, "we have to solve one of the more important
problems in ballistics—that greatest of sciences which treats of the
movement of projectiles—that is to say, of bodies hurled into space by
some power of impulsion and then left to themselves."
"Oh, ballistics, ballistics!" cried J.T. Maston in a voice of emotion.
"Perhaps," continued Barbicane, "the most logical thing would be to
consecrate this first meeting to discussing the engine."
"Certainly," answered General Morgan.
"Nevertheless," continued Barbicane, "after mature deliberation, it
seems to me that the question of the projectile ought to precede that of
the cannon, and that the dimensions of the latter ought to depend upon
the dimensions of the former."
J.T. Maston here interrupted the president, and was heard with the
attention which his magnificent past career deserved.
"My dear friends," said he in an inspired tone, "our president is right
to give the question of the projectile the precedence of every other;
the cannon-ball we mean to hurl at the moon will be our messenger, our
ambassador, and I ask your permission to regard it from an entirely
moral point of view."
This new way of looking at a projectile excited the curiosity of the
members of the committee; they therefore listened attentively to the
words of J.T. Maston.
"My dear colleagues," he continued, "I will be brief. I will lay aside
the material projectile—the projectile that kills—in order to take up
the mathematical projectile—the moral projectile. A cannon-ball is to
me the most brilliant manifestation of human power, and by creating it
man has approached nearest to the Creator!"
"Hear, hear!" said Major Elphinstone.
"In fact," cried the orator, "if God has made the stars and the planets,
man has made the cannon-ball—that criterion of terrestrial speed—that
reduction of bodies wandering in space which are really nothing but
projectiles.
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