PERMISSIVE LIMITS OF IGNORANCE AND BELIEF IN THE UNITED STATES
The immediate result of Barbicane’s proposition was to place upon the
orders of the day all the astronomical facts relative to the Queen of
the Night. Everybody set to work to study assiduously. One would have
thought that the moon had just appeared for the first time, and that no
one had ever before caught a glimpse of her in the heavens. The papers
revived all the old anecdotes in which the “sun of the wolves” played a
part; they recalled the influences which the ignorance of past ages
ascribed to her; in short, all America was seized with selenomania, or
had become moon-mad.
The scientific journals, for their part, dealt more especially with the
questions which touched upon the enterprise of the Gun Club. The letter
of the Observatory of Cambridge was published by them, and commented
upon with unreserved approval.
Until that time most people had been ignorant of the mode in which the
distance which separates the moon from the earth is calculated. They
took advantage of this fact to explain to them that this distance was
obtained by measuring the parallax of the moon. The term parallax
proving “caviare to the general,” they further explained that it meant
the angle formed by the inclination of two straight lines drawn from
either extremity of the earth’s radius to the moon. On doubts being
expressed as to the correctness of this method, they immediately proved
that not only was the mean distance 234,347 miles, but that astronomers
could not possibly be in error in their estimate by more than seventy
miles either way.
To those who were not familiar with the motions of the moon, they
demonstrated that she possesses two distinct motions, the first being
that of rotation upon her axis, the second being that of revolution
round the earth, accomplishing both together in an equal period of
time, that is to say, in twenty-seven and one-third days.
The motion of rotation is that which produces day and night on the
surface of the moon; save that there is only one day and one night in
the lunar month, each lasting three hundred and fifty-four and
one-third hours. But, happily for her, the face turned toward the
terrestrial globe is illuminated by it with an intensity equal to that
of fourteen moons. As to the other face, always invisible to us, it has
of necessity three hundred and fifty-four hours of absolute night,
tempered only by that “pale glimmer which falls upon it from the
stars.”
Some well-intentioned, but rather obstinate persons, could not at first
comprehend how, if the moon displays invariably the same face to the
earth during her revolution, she can describe one turn round herself.
To such they answered, “Go into your dining-room, and walk round the
table in such a way as to always keep your face turned toward the
center; by the time you will have achieved one complete round you will
have completed one turn around yourself, since your eye will have
traversed successively every point of the room. Well, then, the room is
the heavens, the table is the earth, and the moon is yourself.” And
they would go away delighted.
So, then the moon displays invariably the same face to the earth;
nevertheless, to be quite exact, it is necessary to add that, in
consequence of certain fluctuations of north and south, and of west and
east, termed her libration, she permits rather more than half, that is
to say, five-sevenths, to be seen.
As soon as the ignoramuses came to understand as much as the director
of the observatory himself knew, they began to worry themselves
regarding her revolution round the earth, whereupon twenty scientific
reviews immediately came to the rescue. They pointed out to them that
the firmament, with its infinitude of stars, may be considered as one
vast dial-plate, upon which the moon travels, indicating the true time
to all the inhabitants of the earth; that it is during this movement
that the Queen of Night exhibits her different phases; that the moon is
_full_ when she is in _opposition_ with the sun, that is when the three
bodies are on the same straight line, the earth occupying the center;
that she is _new_ when she is in _conjunction_ with the sun, that is,
when she is between it and the earth; and, lastly that she is in her
_first_ or _last_ quarter, when she makes with the sun and the earth an
angle of which she herself occupies the apex.
Regarding the altitude which the moon attains above the horizon, the
letter of the Cambridge Observatory had said all that was to be said in
this respect. Every one knew that this altitude varies according to the
latitude of the observer. But the only zones of the globe in which the
moon passes the zenith, that is, the point directly over the head of
the spectator, are of necessity comprised between the twenty-eighth
parallels and the equator. Hence the importance of the advice to try
the experiment upon some point of that part of the globe, in order that
the projectile might be discharged perpendicularly, and so the soonest
escape the action of gravitation. This was an essential condition to
the success of the enterprise, and continued actively to engage the
public attention.
Regarding the path described by the moon in her revolution round the
earth, the Cambridge Observatory had demonstrated that this path is a
re-entering curve, not a perfect circle, but an ellipse, of which the
earth occupies one of the _foci_. It was also well understood that it
is farthest removed from the earth during its _apogee_, and approaches
most nearly to it at its _perigee_.
Such was then the extent of knowledge possessed by every American on
the subject, and of which no one could decently profess ignorance.
Still, while these principles were being rapidly disseminated many
errors and illusory fears proved less easy to eradicate.
For instance, some worthy persons maintained that the moon was an
ancient comet which, in describing its elongated orbit round the sun,
happened to pass near the earth, and became confined within her circle
of attraction. These drawing-room astronomers professed to explain the
charred aspect of the moon—a disaster which they attributed to the
intensity of the solar heat; only, on being reminded that comets have
an atmosphere, and that the moon has little or none, they were fairly
at a loss for a reply.
Others again, belonging to the doubting class, expressed certain fears
as to the position of the moon. They had heard it said that, according
to observations made in the time of the Caliphs, her revolution had
become accelerated in a certain degree. Hence they concluded, logically
enough, that an acceleration of motion ought to be accompanied by a
corresponding diminution in the distance separating the two bodies; and
that, supposing the double effect to be continued to infinity, the moon
would end by one day falling into the earth. However, they became
reassured as to the fate of future generations on being apprised that,
according to the calculations of Laplace, this acceleration of motion
is confined within very restricted limits, and that a proportional
diminution of speed will be certain to succeed it. So, then, the
stability of the solar system would not be deranged in ages to come.
There remains but the third class, the superstitious. These worthies
were not content merely to rest in ignorance; they must know all about
things which had no existence whatever, and as to the moon, they had
long known all about her. One set regarded her disc as a polished
mirror, by means of which people could see each other from different
points of the earth and interchange their thoughts. Another set
pretended that out of one thousand new moons that had been observed,
nine hundred and fifty had been attended with remarkable disturbances,
such as cataclysms, revolutions, earthquakes, the deluge, etc. Then
they believed in some mysterious influence exercised by her over human
destinies—that every Selenite was attached to some inhabitant of the
earth by a tie of sympathy; they maintained that the entire vital
system is subject to her control, etc. But in time the majority
renounced these vulgar errors, and espoused the true side of the
question. As for the Yankees, they had no other ambition than to take
possession of this new continent of the sky, and to plant upon the
summit of its highest elevation the star- spangled banner of the United
States of America.