it certainly is difficult to imagine we turn round the sun, for we
never change places; we rise in the morning where we went to rest at
night----I see from your look that you are going to tell me, that as
the earth moves altogether----. Assuredly, said I, it is the same thing
as going to sleep in a boat which was sailing down a river; on waking,
you would find yourself in the same boat, and in the same part of the
boat. Yes, replied she, but here is a difference; when I awoke I should
find an alteration in the shore, and that would prove that the boat had
changed its place: it is not so with respect to the earth, I there find
every thing as I left it. No, no, madam, you may observe an alteration
in the shore, as you do in the boat: you will recollect that beyond
all the planets are the fixed stars, these are what we must consider
the objects on the shore. I am on the earth; the earth describes a
large circle round the sun; when I look to the middle of this circle
I find the sun, and were not its brightness so dazzling as to render
the stars invisible, I should constantly see, by looking beyond the
centre, some of the fixed stars opposite to the sun; by viewing them
however at night, I can easily determine how they were situated in
the day, which renders my observations equally accurate. If the earth
remained in the same place I should always find the same fixed stars
answering to the situation of the sun, but as the earth moves on in her
orbit, I necessarily see other fixed stars at the point which I had
before examined. Such is our shore, which is every day varying; and
as the earth goes round the sun in a year, I observe the sun, during
that space of time, successively answering to different fixed stars
which compose a circle; this circle is called the Zodiac; shall I shew
it you by tracing a figure on the earth? No, said she, I can dispense
with that; it would give my park too learned an appearance. I think I
have heard that a philosopher, shipwrecked on an island with which he
was unacquainted, cried out to his companions on perceiving some lines
and circles drawn on the sand; _courage, my friends! the island is
inhabited; here are the footsteps of men_. You must consider that such
_footsteps_ ought not to be seen here.
It would certainly, I replied be more in character, to trace only
the footsteps of lovers; that is to say, your name, engraved by your
adorers on the bark of every tree. No more of adorers, cried she;
let us talk of the sun. I understand perfectly why we imagined it
performing the revolution which is merely effected by our own motion,
but this circle requires a year; how, then, does the sun appear to go
round us every day? You undoubtedly know, I replied, that if a ball
were rolled along this walk it would have two sorts of motion; it would
go towards the end of the walk, and at the same time turn several
times on its own axis, so that the side of the ball which is at first
uppermost will presently descend, and the other, of course, rise to
the top. This is the case with the earth: whilst she is proceeding,
through the year, in her orbit round the sun, she turns on her own axis
every twenty-four hours: each part, therefore, of the earth loses, and
recovers sight of the sun during that time. When in the morning we turn
towards the sun, it seems to rise; and when, by continued rotation, we
again are more distant from it, it appears to descend. That's curious
enough, said she; the earth undertakes every thing, and the sun does
nothing at all: and when the moon, the other planets, and the fixed
stars appear to pass over us in four-and-twenty hours, it is merely
imagination. Exactly so, I replied, and produced by the same cause.
The planets perform their revolutions round the sun in unequal periods
of time, in consequence of their different distances from it; and one
which we see to day answer to a certain point in the zodiac, or circle
of fixed stars, will to-morrow at the same hour answer to some other
point: this is the effect both of the progress which the planet has
made in its orbit and of that which we have made in ours. We move
onward; the other planets do the same, but we do not continue all in a
line: this occasions us to see them in such different situations, and
renders their course apparently irregular. You now understand that such
irregularity depends only on the different points from which we view
them, and that, in reality all their movements are directed by the most
exact order. It may be so, answered the Marchioness; but I should be
glad if their order did not cost the earth so much: you seem to have
very little consideration for it, and to require an astonishing agility
in so large a body. But, said I, do you think it more reasonable for
the sun, and all the other heavenly bodies, which are extremely large,
to perform in four-and-twenty hours an immense journey round the earth?
That the fixed stars, being in the largest circle, should travel, in
the course of a day, more than twenty-seven thousand six hundred and
sixty times two hundred millions of leagues?[11] All this must be if
the earth does not turn on her axis every twenty-four hours. Surely
there is much more rationality in supposing our globe to turn, which
would give to each part but a journey of nine thousand leagues.
Consider what a trifle are nine thousand in comparison of the terrific
number I have just mentioned.
[Footnote 11: According to later calculations, it would be a thousand
millions of times a million of leagues; but a person who did not
believe the motion of the earth would have no occasion to admit this
prodigious distance.]
Oh! replied the Marchioness; the sun and stars are made of fire, a
swift motion is nothing to them, but the earth does not seem formed for
motion. And should you think, I answered, if experience had not proved
the fact, that a large ship, carrying a hundred and fifty pieces of
cannon, three thousand men, and a heavy freight of merchandize, could
be _formed for motion_?--Yet a gentle breeze is sufficient to move it
forwards, because the water, being liquid, and easily divided, makes a
very slight resistance to the progress of the ship, or if it be in the
middle of a river, it follows without difficulty the current of the
water, since there is then no impediment. In like manner the earth,
notwithstanding its weight, is with facility carried through the sky
which is infinitely more fluid than water, and which fills the immense
space occupied by all the planets. To what could the earth be fastened
so strongly as to resist the current of this celestial fluid and remain
motionless? We might as well imagine a little wooden ball could resist
the tide of a river.
But, said she, how can a body so ponderous as the earth be suspended
in your celestial fluid, which from its great fluidity must be
extremely light? It does not follow, I replied, that a substance must
be extremely light because it is fluid. What do you think of the great
ship we have been talking of, which, with all its lading, is lighter
than the water that supports it? I won't have any more to say to
you, answered she, half angrily, if you mention your ship again.[12]
But tell me, is it not dangerous to inhabit such a whirli-gig as
you represent the earth? If you are afraid, said I, let us have the
world supported by four elephants, as the Indians do. Well! cried
she, here is a new system. I like those people for providing such
good foundations for the earth to rest on, whilst we Copernicans are
imprudent enough to swim at random in this celestial fluid. I dare say
if the Indians knew there was the least danger of the earth's being
moved, they would double the number of elephants.
[Footnote 12: The Marchioness was in the right not to listen to such
an answer. It is absurd to pretend that the ætherial fluid, so light
and rare, can be capable of bearing along those enormous masses, the
planets.]
It would be worth while, I replied, laughing at the thought, we must
not be sparing of elephants if they can enable us to sleep in peace;
if you would find them serviceable to-night we'll put as many as you
please, and then remove them one or two at a time as you find your
courage return. No, said she, I don't think there is any need for
them, and to speak seriously, I feel courageous enough to let the
world turn round. And I can venture to predict, answered I, that in
a little while its turning will give you pleasure; will even inspire
the most delightful ideas, I sometimes imagine myself raised above
the surface of the earth, and remaining motionless whilst its daily
rotation continues. All the different inhabitants pass in review; some
fair, some copper-coloured, some black. Now I see heads covered with
hats; then with turbans; some shaven, others with flowing hair. As the
towns pass before me, I observe some have steeples, some long spires
with crosses on them, others are ornamented with towers of porcelaine.
Then I behold large countries with no other buildings than little huts:
afterwards, immense seas; then frightful deserts; and in short, all the
boundless variety which is to be found on the face of the earth.
Really, she replied, it would be worth while to devote four-and-twenty
hours to such a sight. If I understand you, when we move, other
countries with their inhabitants pass into the situation we are
leaving, and so on, till in four-and-twenty hours we again arrive at
the same place.
Copernicus himself, said I, could not have comprehended it more
clearly. The first that would succeed us[13] would be the English: we
should probably find them arguing on some political topic with less
gaiety than we are discussing our philosophy. When we had dismissed
them we should discover a vast sea,[14] on which perhaps would be
some vessel, less at her ease than we. Then come the Iroquois, eating
one of their prisoners of war, who does not even utter a groan though
still alive when they begin to devour him.[15] After them the women
of Jesso, who employ all their time in preparing victuals for their
husbands, and painting their lips and eye-brows blue to appear handsome
in the eyes of the most disgusting men in the world. Then the Tartars,
very devoutly going on a pilgrimage to their high priest, who dwells
in an obscure recess, enlightened only by lamps, the rays of which
direct these votaries to the object of their adoration. Afterwards
the beautiful Circassians who make no ceremony of granting all their
favours to the first that solicits them, except what they believe the
essential prerogative of their husbands. Then the inhabitants of Little
Tartary, who go to steal women for the Turks and Persians. Last of all
our countrymen, whom we should find entertaining each other with the
vagaries of their imagination.
[Footnote 13: To speak more properly they would be one hundred leagues
northward.]
[Footnote 14: The Atlantic.]
[Footnote 15: We should next see the Pacific Ocean.]
It is amusing enough, said the Marchioness, to fancy oneself in a
situation to see all these things: but if I were taking the view I
should wish for the power of hastening or retarding the earth's motion,
according to the feelings with which each object inspired me: I assure
you I should soon push on those that argued on politics, and the
others that devoured their enemies; but there are some of the people
you have been speaking of that would excite my curiosity; the handsome
Circassians, for instance, whose customs are so peculiar. But a serious
difficulty occurs to me respecting your system. If the earth turns, we
every moment change our atmosphere, and respire that of a new climate.
By no means, madam, I replied; the air which surrounds the earth rises
only to a certain height, twenty leagues perhaps at farthest;[16] this
atmosphere always turns with us. You have doubtless observed the sort
of shell in which a silk-worm imprisons itself, and which it forms
with such astonishing art. It is composed of silk closely woven, but
covered with a light down. Thus it is with regard to the earth, it is a
solid body covered with an atmosphere extending to a certain height,
which adheres to, and moves with it, as the down does with the firmer
substance beneath it. Above our atmosphere is the celestial matter,
incomparably more pure, subtile and active than air.
[Footnote 16: Even at two leagues it is no longer discernible.]
You represent the earth in a very contemptible light, said the
Marchioness. Nevertheless on this silk-worm's shell we find stupendous
works, furious wars, and universal agitation. Yes, answered I, and
while all this is going on, nature, who does not concern herself about
such frivolous things, carries us all along, with an uninterrupted
motion, and amuses herself with the little ball.
It appears very ridiculous, replied she, to give way to so much
anxiety, whilst one is living on a thing that is perpetually turning;
but unfortunately we are not assured that it does turn, for, to tell
you the truth, all the precautions you take to convince me that we
should not feel its motion are unsatisfactory. How could it avoid
giving some indication by which we should be sensible of it?[17] The
most common and natural motions, said I, are the least felt: this
observation is true even in a moral sense: the motions of self-love are
so frequent in our minds, that for the most part we are not sensible
of them, but believe ourselves actuated by other principles. Ah! you
are beginning to moralize, said she; moralizing and explaining natural
philosophy are a little different; I fancy you grow tired of your
subject: let us return home, we have had enough for the first lecture.
To-morrow we will come here again--you with your systems, and I with my
ignorance.
[Footnote 17: There are several; one of them is the aberration of the
stars. Astron. Book xvii.]
In our way to the house, to give her a complete history of systems,
I told her that a third had been invented by Ticho Brahe, who, from
a determination to keep the earth in a state of rest, placed her in
the centre of the universe, making the sun revolve round her, and the
planets round the sun; for in consequence of some discoveries which had
been lately made, he found it impossible to make the planets go round
the earth. The Marchioness, with her usual discernment, concluded that
it was mere whim to exempt the earth from moving round the sun, when
so many other larger bodies were allowed to perform the revolution;
that the sun was rendered more unfit for turning round the earth when
incumbered with the other planets, and in short that this system
was only calculated to support a prejudice in favour of the earth's
immobility,[18] without offering any thing to convince the judgment;
we therefore resolved to retain that of Copernicus, which is more
uniform and pleasing, and at the same time unmixed with prejudice. In
fact its simplicity convinces, whilst its boldness excites admiration.
[Footnote 18: The ridiculous system of Ticho was invented out of
respect to the holy scriptures, not considering that their object
was more important than the refutation of popular errors on natural
philosophy.]
═══════════
_SECOND EVENING._
═══════════
THE MOON IS A HABITABLE GLOBE.
═══════════
The next morning as soon as the Marchioness was awake, I sent to
enquire how she did, and whether she had been able to sleep whilst the
globe was turning? I received for answer, that she already felt quite
accustomed to the motion; and had slept as undisturbedly as Copernicus
himself. Soon afterwards, some company came to spend the whole day
with her; a tiresome custom which is always observed in the country;
yet long as the visit was, we considered it a great kindness in the
guests, not to prolong it to the next day; which I find is a common
practice in this part of the world: however, as they had the civility
to leave us, the Marchioness and I had the evening to ourselves. We
immediately went to the park and resumed our astronomical conversation.
She understood so perfectly all I had said on the former evening, that
she disdained to hear any repetition of the subject, and desired me
to enter on a new one.--Well then, said I, since the sun, which we
concluded is immovable, can no longer be considered a planet; and the
earth is proved to be one, and to move round the sun; you will be the
less surprised to hear, that the moon is a world like ours; and to all
appearance, inhabited.--I never heard speak of peopling the moon; she
replied, but as a ridiculous, visionary hypothesis.--It may be so,
answered I; I only adopt the interest of any party, in these cases, as
people do in civil wars; in which the uncertainty of the event, induces
them to hold a correspondence with opposite sides, and even, when
possible, with their enemies. For my part, though I believe the moon is
inhabited, I can be very civil to any one that disbelieves it; and I
always retain the power of going over to their side without disgracing
myself, if I found they had the advantage: but in the present state
of the question I have the following reasons for thinking the moon is
inhabited.
Let us suppose that no communication had ever been carried on between
Paris and St. Dennis; and that a Parisian who had never gone out of his
own city should stand on one of the towers of Notre-Dame, and at that
distance view St. Dennis: were he asked if he believed that St. Dennis
was inhabited like Paris, he would without hesitation answer, No; I see
inhabitants in Paris, but I can discover none at St. Dennis, nor did
I ever hear of any being there. Somebody standing by, might answer,
that we certainly cannot see them from the towers of Notre-Dame, but
that is, because we are at too great a distance; that from all we can
discern of St. Dennis it is very much like Paris; that it has steeples,
houses, walls; and therefore is very probably inhabited. All this makes
no impression on our citizen; he insists upon it that St. Dennis is
uninhabited because he does not see any body in it. The moon is our St.
Dennis, and each of us is this Parisian who has never left the city in
which he resides.
Oh! you wrong us, interrupted the Marchioness; we are not so stupid as
your citizen; when he sees that St. Dennis is constructed exactly on
the same plan as Paris, he must be out of his senses not to believe
it inhabited: but the moon is very different from the earth. Be
cautious, madam, said I; if the moon's resemblance to the earth prove
it habitable, I shall force you to believe that it is inhabited. I
confess, answered she, that if you can shew me the similarity, I cannot
pretend to deny its being inhabited, and I see so much confidence in
your looks that I am afraid you will be triumphant. The two different
motions of the earth, which I never before knew any thing about, make
me fearful of hastily rejecting any other opinion; but still, can it be
possible that the earth is luminous like the moon?--that you know is
essential to their similarity. Indeed, madam, I replied, the luminous
quality of planets depends on less than you imagine. The sun alone is,
in his _nature_, luminous; but the planets only reflect the light they
receive from him. He enlightens the moon; the moon reflects his rays on
the earth, and the earth is undoubtedly in the same manner a source of
light to the moon; it is not farther from us to the moon, than from the
moon to us.
But, enquired the Marchioness, is the earth equally capable of
reflecting the sun's light? I see, answered I, you have an invincible
partiality for the moon. Light is composed of globules which rebound
from a solid substance, but pass through any thing in which they find
interstices, such as air or glass: the moon, therefore, gives us light
in consequence of being a hard, solid body, which sends back these
globules. I suppose you will not dispute the hardness and solidity of
the earth. See then the effect of an advantageous situation--because
the moon is at a distance we only view her as a luminous body instead
of a large mass of matter similar to the earth. Our globe, on the
contrary, from having the ill luck to be more closely inspected,
appears only a mass of dark soil, fit for nothing but to produce food
for animals; we do not perceive the splendour of her light, because
we cannot remove to a distance from her. So it is, answered the
Marchioness, with the different ranks of society: we are dazzled with
the grandeur of situations superior to our own, without considering how
much every condition of human life resembles all the rest.
'Tis precisely the same thing, I replied; we take upon us to decide
on every thing, but we are never in a proper place for making our
observations. We would form an opinion of ourselves, and we are too
near; we would judge of others; they are too distant from our view.
We should be placed between the earth and the moon to form a just
comparison; a spectator, not an inhabitant of the world. I shall be
inconsolable for the injustice we do our world, said she, and the
partial regard we have for the moon, unless you can assure me that the
inhabitants of that planet are as ignorant of _their_ advantages, and
consider our globe a luminous body, without knowing that from their own
we derive so much light. I can make you easy on that head, answered
I; we are certainly a luminary to them: they do not, it is true, see
us describe a circle round them,[19] but that does not signify. The
reason of our appearing to remain in the same place is this;--the
side of the moon which was turned towards us at the creation, has
always continued so; we always observe the same eyes, mouth, and
other features of the face which, by the help of imagination, we have
contrived out of the spots on her surface.[20] If the other half were
presented to us, we should see spots arranged in a different form:
this does not arise from the moon's not turning on her axis; she turns
in the same time that is employed in going round the earth, that is,
a month; but whilst she is performing part of her revolution on her
axis, she at the same time performs an equal part of her circle round
the earth, and thus, by putting herself in a new situation, continues
to shew the same side: therefore although with regard to the sun and
the rest of the heavenly bodies the moon evidently turns on her axis,
yet when viewed from the earth she does not appear to do so. All the
other luminaries seem to the moon to rise and set in the space of a
fortnight, but she constantly sees our globe in the same part of the
heavens.[21] This apparent immobility, were it invariable, would be
thought inconsistent with the nature of a planet; but the moon has a
sort of vibratory motion which sometimes conceals a small part of the
face, and exhibits a part of the other side. Now, I can venture to say
that the inhabitants attribute this motion to us, and imagine that we
vibrate in the heavens, like a pendulum.
[Footnote 19: This is an error, for if they consider the earth's
situation relatively to the firmament, they must see that she performs
a revolution in twenty-seven days: they certainly always find her
answer to their zenith, or at the same distance from the zenith, but at
the same time this zenith is continually answering to some new point in
the heavens.]
[Footnote 20: When the moon is viewed through a telescope its spots
bear no resemblance to the human face; but on contemplating it with the
naked eye, it is easy to imagine that form; and it is become so common
to talk of the face on the moon, that even an astronomer can hardly
divest himself of the idea.]
[Footnote 21: The earth always answers to one side of the moon, but not
the same point in the sky.]