THE EARTH
Our grand celestial journey lands us upon our own little planet, on this
globe that gravitates between Mars and Venus (between War and Love),
circulating like her brothers of the solar system, around the colossal
Sun.
The Earth! The name evokes in us the image of Life, and calls up the
theater of our activities, our ambitions, our joys and sorrows. Does it
not, in fact, to ignorant eyes, represent the whole of the universe?
And yet, what is the Earth?
The Earth is a star in the Heavens. We learned this much in our first
lesson. It is a globe of opaque material, similar to the planets
Mercury, Venus, Mars, Jupiter, etc., as previously described. Isolated
on all sides in space, it revolves round the Sun, along a vast orbit
that it accomplishes in a year. And while it thus glides along the lines
of solar attraction, the terrestrial ball rotates rapidly upon itself in
twenty-four hours.
These statements may appear dubious at first sight, and contradictory to
the evidence of our senses.
Now that the surface of the Earth has been explored in all directions,
there is no longer room to doubt that it is a globe, a sort of ball that
we adhere to. A journey round the world is common enough to-day, and
always yields the most complete evidence of the spherical nature of the
Earth. On the other hand, the curvature of the seas is a no less certain
proof. When a ship reaches the dark-blue line that appears to separate
the sky from the ocean, it seems to be hanging on the horizon. Little by
little, however, as it recedes, it drops below the horizon line; the
tops of the masts being the last to disappear. The observer on board
ship witnesses the same phenomenon. The low shores are first to
disappear, while the high coasts and mountains are much longer visible.
The aspect of the Heavens gives another proof of the Earth's rotundity.
As one travels North or South, new stars rise higher and higher above
the horizon in the one direction or the other, and those which shine in
the latitude one is leaving, gradually disappear. If the surface of the
Earth were flat, the ships on the sea would be visible as long as our
sight could pierce the distance, and all the stars of the Heavens would
be equally visible from the different quarters of the world.
Lastly, during the eclipses of the Moon, the shadow projected by the
Earth upon our satellite is always round. This is another proof of the
spherical nature of the terrestrial globe.
We described the Earth as an orb in the Heavens, similar to all the
other planets of the great solar family. We see these sister planets of
our world circulating under the starry vault, like luminous points whose
brilliancy is sometimes dazzling. For us they are marvelous celestial
birds hovering in the ether, upheld by invisible wings. The Earth is
just the same. It is supported by nothing. Like the soap-bubble that
assumes a lovely iridescence in the rays of the Sun, or, better, like
the balloon rapidly cleaving the air, it is isolated from every kind of
support.
Some minds have difficulty in conceiving this isolation, because they
form a false notion of weight.
The astronomers of antiquity, who divined it, knew not how to prevent
the Earth from falling. They asked anxiously what the strong bands
capable of holding up this block of no inconsiderable weight could be.
At first they thought it floated on the waters like an island. Then they
postulated solid pillars, or even supposed it might turn on pivots
placed at the poles. But on what would all these imaginary supports have
rested? All these fanciful foundations of the Earth had to be given up,
and it was recognized as a globe, isolated in every part. This illusion
of the ancients, which still obtains for a great many citizens of our
globule, arises, as we said, from a false conception of weight.
Weight and attraction are one and the same force.
A body can only fall when it is attracted, drawn by a more important
body. Now, in whatever direction we may wander upon the globe, our feet
are always downward. _Down_ is therefore the _center_ of the Earth.
The terrestrial globe may be regarded as an immense ball of magnet, and
its attraction holds us at its surface. We weigh toward the center. We
may travel over this surface in all directions; our feet will always be
below, whatever the direction of our steps. For us, "below" is the
inside of our planet, and "above" is the immensity of the Heavens that
extend above our heads, right round the globe.
This once understood, where could the Earth fall to? The question is an
absurdity. "Below" being toward the center, it would have to fall out of
itself.
Let us then picture the Earth as a vast sphere, detached from all that
exists around it, in the infinity of the Heavens. A point diametrically
opposed to another is called its _antipodes_. New Zealand is
approximately the antipodes to France. Well, for the inhabitants of New
Zealand and of France the top is reciprocally opposed, and the bottom,
or the feet, are diametrically in opposition. And yet, for one as for
the other, the bottom is the soil they are held to, and the top is
space above their heads.
The Earth turns on itself in twenty-four hours. Whatever is above us,
_e.g._, at midday, we call high; twelve hours later, at midnight, we
give the same qualification to the part of space that was under our feet
at noon. What is in the sky, and over our heads, at a given hour, is
under our feet, and yet always in the sky, twelve hours later. Our
position, in relation to the space that surrounds us, changes from hour
to hour, and "top" and "bottom" vary also, relatively to our position.
Our planet is thus a ball, slightly flattened at the poles (by about
1/292). Its diameter, at the equator, is 12,742 kilometers (7,926
miles); from one pole to the other is a little less, owing to the
flattening of the polar caps. The difference is some 43 kilometers
(about 27 miles).
Its circumference is 40,000 kilometers (24,900 miles). This ball is
surrounded by an aerial envelope, the atmosphere, the height of which
can not be less than 300 kilometers (186 miles), according to the
observations made on certain shooting stars.
We all know that this layer of air, at the bottom of which we live, is a
beautiful azure blue that seems to separate us from the sidereal abyss,
spreading over our heads in a kind of vault that is often filled with
clouds, and giving the illusion of resting far off on the circle of the
horizon. But this is only an illusion. In reality, there is neither
vault nor horizon; space is open in all directions. If the atmosphere
did not exist, or if it were completely transparent, we should see the
stars by day as by night, for they are continually round us, at noon as
at midnight, and we can see them in the full daylight, with the help of
astronomical instruments. In fact, certain stars (the radiant Venus and
the dazzling Jupiter) pierce the veil of the atmosphere, and are visible
with the unaided eye in full daylight.
The terrestrial surface is 510,000,000 square kilometers (200,000,000
square miles). The waters of the ocean cover three-quarters of this
surface, _i.e._, 383,200,000 square kilometers (150,000,000 square
miles), and the continents only occupy 136,600,000 square kilometers
(55,000 square miles). France represents about the thousandth part of
the total superficies of the globe.
Despite the asperities of mountain ranges, and the abysses hollowed out
by the waters, the terrestrial globe is fairly regular, and in relation
to its volume its surface is smoother than that of an orange. The
highest summits of the Himalaya, the profoundest depths of the somber
ocean, do not attain to the millionth part of its diameter.
In weight, the Earth is five and a half times heavier than would be a
globe of water of the same dimensions. That is to say:
6,957,930,000,000,000,000,000,000 kilograms
(6,833,000,000,000,000,000,000 tons).
The atmospheric atmosphere with which it is surrounded represents.
6,263,000,000,000,000,000 kilograms
(6,151,000,000,000,000 tons).
Each of us carries an average weight of some 17,000 kilograms (16 tons)
upon his shoulders. Perhaps some one will ask how it is that we are not
crushed by this weight, which is out of all proportion with our
strength, but to which, nevertheless, we appear insensible. It is
because the aerial fluid enclosed within our bodies exerts a pressure
equal and opposite to the external atmospheric pressure, and these
pressures are at equilibrium.
The Earth is characterized by no essential or particular differences
relatively to the other worlds of our system. Like Venus of the limpid
rays, like the dazzling Jupiter, like all the planets, she courses
through space, carrying into Infinitude our hopes and destinies. Bigger
than Mercury, Venus, and Mars, she presents a very modest figure in
comparison with the enormous Jupiter, the strange system of Saturn, of
Uranus, and even of Neptune. For us her greatest interest is that she
serves as our residence, and if she were not our habitation we should
scarcely notice her. Dark in herself, she burns at a distance like a
star, returning to space the light she receives from the Sun. At the
distance of our satellite, she shines like an enormous moon, fourteen
times larger and more luminous than our gentle Phoebe. Observed from
Mercury or Venus, she embellishes the midnight sky with her sparkling
purity as Jupiter does for us. Seen from Mars, she is a brilliant
morning and evening star, presenting phases similar to those which Mars
and Venus show from here. From Jupiter, the terrestrial globe is little
more than an insignificant point, nearly always swallowed up in the
solar rays. As to the Saturnians, Uranians, and Neptunians, if such
people exist, they probably ignore our existence altogether. And in all
likelihood it is the same for the rest of the universe.
We must cherish no illusions as to the importance of our natal world. It
is true that the Earth is not wanting in charm, with its verdant plains
enameled in the delicious tones of a robust and varied vegetation, its
plants and flowers, its spring-time and its birds, its limpid rivers
winding through the meadows, its mountains covered with forests, its
vast and profound seas animated with an infinite variety of living
creatures. The spectacle of Nature is magnificent, superb, admirable
and marvelous, and we imagine that this Earth fills the universe, and
suffices for it. The Sun, the Moon, the stars, the boundless Heavens,
seem to have been created for us, to charm our eyes and thoughts, to
illumine our days, and shed a gentle radiance upon our nights. This is
an agreeable illusion of our senses. If our Humanity were extinguished,
the other worlds of the Heavens, Venus, Mars, etc., would none the less
continue to gravitate in the Heavens along with our defunct planet, and
the close of human life (for which everything seems to us to have been
created) would not even be perceived by those other worlds, that
nevertheless are our neighbors. There would be no revolution, no
cataclysm. The stars would go on shining in the firmament, just as they
do to-day, shedding their divine light over the immensity of the
Heavens. Nothing would be changed in the general aspect of the Universe.
The Earth is only a modest atom, lost in the innumerable army of the
worlds and suns that people the universe.
* * * * *
Every morning the Sun rises in the East, setting fire with his ardent
rays to the sky, which is dazzling with his splendor. He ascends through
space, reaches a culminating point at noon, and then descends toward the
West, to sink at night into the purple of the sunset.
And then the stars, grand lighthouses of the Heavens, in their turn
incandesce. They too rise in the East, ascend the vault of Heaven, and
then descend to the West, and vanish. All the orbs, Sun, Moon, planets,
stars, appear to revolve round us in twenty-four hours.
This journey of the orbs around us is only an illusion of the senses.
Whether the Earth be at rest, and the sky animated with a rotary
movement round her, or whether, on the contrary, the stars are fixed,
and the Earth in motion, in either case, for us appearances are the
same. If the Earth turns, carrying all that pertains to it in its
motion--the seas, the atmosphere, the clouds, and ourselves,--we are
unable to perceive it, because all the objects that surround us keep
their respective positions among themselves. Hence we must resort to
logic, and reason out the two hypotheses.
For the accomplishment of this rapid journey of the Sun and stars around
the Earth, it would be necessary that all the orbs of the sky should be
in some way attached to a vault, or to circles, as was formerly
supposed. This conception is childish. The peoples of antiquity had no
notion of the size of the universe, and their error is almost excusable.
The distance separating Heaven from the Infernal Regions has been
measured, according to Hesiod, by Vulcan's anvil, which fell from the
skies to the Earth in nine days and nine nights, and it would have
taken as long again to continue its journey from the surface of the
Earth to the bowels of Hades.
To-day we have a more exact notion of the grandeur of the Universe. We
know that millions and trillions of miles separate the stars from one
another. And by representing these distances, we can form some idea of
the difficulty there would be in admitting the rotation of the universe
round the Earth.
The distance from here to the Sun is 149,000,000 kilometers (93,000,000
miles). In order to turn in twenty-four hours round the Earth, that orb
would have to fly through Space at a velocity of more than 10,000
kilometers (6,200 miles) a second.
Yes! the Sun, splendid orb, source of our existence and of that of all
the planets, a colossal globe, over a million times more voluminous than
the Earth, and 324 thousand times heavier, would have to accomplish this
immense revolution in order to turn round the minute point that is our
lilliputian world!
This in itself would suffice to convince us of the want of logic in such
an argument. But the Sun is not alone in the Heavens. We should have to
suppose that all the planets and all the stars were engaged in the same
fantastic motions.
Jupiter is about five times as far off as the Sun; his velocity would
have to be 53,000 kilometers (32,860 miles) per second.
Neptune, thirty times farther off, would have to execute 320,000
kilometers (198,000 miles) per second.
The nearest star, [alpha] of the Centaur, situated at a distance 275,000
times that of the Sun, would have to run, to fly through space, at a
rate of 2,941,000,000 kilometers (1,823,420,000 miles) per second.
All the other stars are incomparably farther off, at infinity.
And this fantastic rotation would all be accomplished round a minute
point!
To put the problem in this way is to solve it. Unless we deny the
astronomic measures, and the most convincing geometric operations, the
Earth's diurnal motion of rotation is a certainty.
To suppose that the stars revolve round the Earth is to suppose, as one
author humorously suggests, that in order to roast a pheasant the
chimney, the kitchen, the house, and all the countryside must needs turn
round it.
If the Earth turns in twenty-four hours upon itself, a point upon the
equator would simply travel at a rate of 465 meters (1,525 feet) per
second. This speed, while considerable in comparison with the movements
observed upon the surface of our planet, is as nothing compared with
the fantastic rapidity at which the Sun and stars would have to move, in
order to rotate round our globe.
Thus we have to choose between these two hypotheses: either to make the
entire Heavens turn round us in twenty-four hours, or to suppose our
globe to be animated by a motion of rotation upon itself. For us, the
impression is the same, and as we are insensible to the motion of the
Earth, its immobility would seem almost natural to us. So that, in last
resort, here as in many other instances, the decision must be made by
simple common sense. Science long ago made its choice. Moreover, all the
progress of Astronomy has confirmed the rotary movement of the Earth in
twenty-four hours, and its movement of revolution round the Sun in a
year; while at the same time a great number of other motions have been
discovered for our wandering planet.
The learned philosophers of antiquity divined the double movement of our
planet. The disciples of Pythagoras taught it more than two thousand
years ago, and the ancient authors quote among others Nicetas of
Syracuse, and Aristarchus of Samos, as being among the first to promote
the doctrine of the Earth's movement. But at that remote period no one
had any idea of the real distances of the stars, and the argument did
not seem to be based on any adequate evidence. Ptolemy, after a long
discussion of the diurnal motion of our planet, refutes it, giving as
his principal reason that if the Earth turned, the objects that were not
fixed to its surface would appear to move in a contrary direction, and
that a body shot into the air would fall back to the West of its
starting-point, the Earth having turned meantime from West to East. This
objection has no weight, because the Earth controls not only all the
objects fixed to the soil, but also the atmosphere, and the clouds that
surround it like a light veil, and all that exists upon its surface. The
atmosphere, the clouds, the waters of the ocean, things and beings, all
are adherent to it and make one body with it, participating in its
movement, as sometimes happens to ourselves in the compartment of a
train, or the car of an aerostat. When, for instance, we drop an object
out of such a car, this object, animated with the acquired velocity,
does not fall to a point below the aerostat, but follows the balloon, as
though it were gliding along a thread. The author has made this
experiment more than once in aerial journeys.
Thus, the hypothesis of the Earth's motion has become a certainty. But
in addition to reasoning, direct proof is not wanting.
1. The spheroidal shape of the Earth, slightly flattened at the poles
and swollen at the equator, has been produced by the rotary motion, by
the centrifugal force that it engenders.
2. In virtue of this centrifugal force, which is at its maximum at the
equator, objects lose a little of their weight in proportion as they are
farther removed from the polar regions where centrifugal force is almost
_nil_.
3. In virtue of this same centrifugal force, the length of the pendulum
in seconds is shorter at the equator than in Paris, and the difference
is one of 3 millimeters.
4. A weight abandoned to itself and falling from a certain height,
should follow the vertical if the Earth were motionless. Experiment,
frequently repeated, shows a slight deviation to the East, of the
plumb-line that marks the vertical. We more especially observed this at
the Pantheon during the recent experiments.
5. The magnificent experiment of Foucault at the Pantheon, just renewed
under the auspices of the Astronomical Society of France, demonstrates
the rotary motion of the Earth to all beholders. A sufficiently heavy
ball (28 kilograms, about 60 pounds) is suspended from the dome of the
edifice by an excessively fine steel thread. When the pendulum is in
motion, a point attached to the bottom of the ball marks its passage
upon two little heaps of sand arranged some yards away from the center.
At each oscillation this point cuts the sand, and the furrow gets
gradually longer to the right hand of an observer placed at the center
of the pendulum. The plane of the oscillations remains fixed, but the
Earth revolves beneath, from West to East. The fundamental principle of
this experiment is that the plane in which any pendulum is made to
oscillate remains invariable even when the point of suspension is
turned. This demonstration enables us in some measure to see the Earth
turning under our feet.
The annual displacements of the stars are again confirmatory of the
Earth's motion round the Sun. During the course of the year, the stars
that are least remote from our solar province appear to describe minute
ellipses, in perspective, in the Heavens. These small apparent
variations in the position of the nearest stars reproduce the annual
rotation of the Earth round the Sun, in perspective.
We could adduce further observations in favor of this double movement,
but the proofs just given are sufficiently convincing to leave no doubt
in the mind of the reader.
Nor are these two the only motions by which our globe is rocked in
space. To its diurnal rotation and its annual rotation we may add
another series of _ten more motions_: some very slow, fulfilling
themselves in thousands of years, others, more rapid, being constantly
renewed. It is, however, impossible in these restricted pages to enter
into the detail reserved for more complete works. We must not forget
that our present aim is to sum up the essentials of astronomical
knowledge as simply as possible, and to offer our readers only the "best
of the picking."
* * * * *
The two principal motions of which we have just spoken give us the
measure of time, the day of twenty-four hours, and the year of 365-1/4
days.
The Earth turning upon itself in twenty-four hours from West to East,
presents all its parts in succession to the Sun fixed in space.
Illuminated countries have the day, those opposite, in the shadow of the
Earth, are plunged into night. The countries carried by the Earth toward
the Sun have morning, those borne toward his shadow, evening. Those
which receive the rays of the day-star directly have noon; those which
are just opposite have midnight.
The rotation of our planet in this way gives us the measure of time; it
has been divided arbitrarily into twenty-four periods called hours; each
hour into sixty minutes; each minute into sixty seconds.
In consequence, each country turns in twenty-four hours round the axis
of the Earth. The difference in hours between the different regions of
the globe is therefore regulated by the difference of geographical
position. The countries situated to the West are behind us; the Sun only
gets there after it has shone upon our meridian. When it is midday in
Paris, it is only 11.51 A.M. in London; 11.36 A.M. in Madrid; 11.14 A.M.
at Lisbon; 11.12 A.M. at Mogador; 7.06 A.M. at Quebec; 6.55 A.M. at New
York; 5.14 A.M. in Mexico; and so on. The countries situated to the East
are, on the contrary, ahead of us. When it is noon in Paris, it is
already 56 minutes after midday at Vienna; 1.25 P.M. at Athens; 2.21
P.M. at Moscow; 3.16 P.M. at Teheran; 4.42 P.M. at Bombay; and so on. We
are here speaking of real times, and not of the conventional times.
[Illustration: FIG. 60.--Motion of the Earth round the Sun.]
If we could make the tour of the world in twenty-four hours, starting
at midday from some place to go round the globe, and traveling westward
with the Sun, we should have him always over our heads. In traveling
round the world from West to East, one goes in front of the Sun, and
gains by one day; in taking the opposite direction, from East to West,
one loses a day.
In reality, the exact duration of the Earth's diurnal rotation is
twenty-three hours, fifty-six minutes, four seconds. That is the
sidereal day. But, while turning upon itself, the Earth circulates upon
its orbit, and at the end of a diurnal rotation it is still obliged to
turn during three minutes, fifty-six seconds in order to present exactly
the same meridian to the fixed Sun which, in consequence of the rotary
period of our planet, is a little behind. The solar day is thus one of
twenty-four hours. There are 366 rotations in the year.
And now let us come back to the consequences of the Earth's motion. In
the first place our planet does not turn vertically nor on its side, but
is tipped or inclined a certain quantity: 23 deg. 27'.
Now, throughout its annual journey round the Sun, the inclination
remains the same. That is what produces the seasons and climates. The
countries which have a larger circle to travel over in the hemisphere of
the solar illumination have the longer days, those which have a smaller
circle, shorter days. At the equator there is constantly, and all
through the year, a twelve-hour day, and a night of twelve hours.
[Illustration: FIG. 61.--Inclination of the Earth.]
In summer, the pole dips toward the Sun, and the rays of the orb of day
cover the corresponding hemisphere with their light. Six months later
this same hemisphere is in winter, and the opposite hemisphere is in its
turn presented to the Sun. June 21 is the summer solstice for the
northern hemisphere, and is at the same time winter for the southern
pole. Six months later, on December 21, we have winter, while the
southern hemisphere is completely exposed to the Sun. Between these two
epochs, when the radiant orb shines exactly upon the equator, that is on
March 21, we have the spring equinox, that delicious flowering season
when all nature is enchanting and enchanted; on September 21 we have the
autumn equinox, melancholy, but not devoid of charm.
The terrestrial sphere has been divided into different zones, with which
the different climates are in relation:
1. The tropical zone, which extends 23 deg. 27' from one part to the other
of the equator. This is the hottest region. It is limited by the circle
of the tropics.
2. The temperate zones, which extend from 23 deg. 27' to 66 deg. 23' of
latitude, and where the Sun sets every day.
3. The glacial zones, drawn round the poles, at 66 deg. 33' latitude, where
the Sun remains constantly above or below the horizon for several days,
or even several months. These glacial zones are limited by the polar
circles.
We must add that the _axis_ of the Earth is a straight line that is
supposed to pass through the center of the globe and come out at two
diametrically opposite points called the _poles_. The diurnal rotation
of the Earth is effected round this axis.
The name _equator_ is given to a great circle situated between the two
poles, at equal distance, which divides the globe into two hemispheres.
The equator is divided into 360 parts or degrees, by other circles that
go from one pole to the other. These are the _longitudes_ or meridians
(see Fig. 62). The distance between the equator and the pole is divided
into larger or smaller circles, which have received the name of
_latitudes_, 90 degrees are reckoned on the one side and the other of
the equator, in the direction of the North and South poles,
respectively. The longitudes are reckoned from some point either to East
or West: the latitudes are reckoned North and South, from the equator.
In going from East to West, or inversely, the longitude changes, but in
passing from North to South of any spot, it is the latitude that alters.
[Illustration: FIG. 62.--The divisions of the globe. Longitudes and
latitudes.]
The circles of latitude are smaller in proportion as one approaches the
poles. The circumference of the world is 40,076,600 meters at the
equator. At the latitude of Paris (48 deg. 50') it is only 26,431,900
meters. A point situated at the equator has more ground to travel over
in order to accomplish its rotation in twenty-four hours than a point
nearer the pole.
We have already stated that this velocity of rotation is 465 meters per
second at the equator. At the latitude of Paris it is not more than 305
meters. At the poles it is _nil_.
The longitudes, or meridians, are great circles of equal length,
dividing the Earth into quarters, like the parts of an orange or a
melon. These circumvent the globe, and measure some 40,000,000
(40,008,032) meters. We may remember in passing that the length of the
meter has been determined as, by definition, the ten-millionth part of
the quarter of a celestial meridian.
Thus, while rotating upon itself, the Earth spins round the Sun, along a
vast orbit traced at 149,000,000 kilometers (93,000,000 miles) from the
central focus, a sensibly elliptical orbit, as we have already pointed
out. It is a little nearer the Sun on January 1st than on July 1st, at
its perihelion (_peri_, near, _helios_, Sun), than at its aphelion
(_apo_, far, _helios_, Sun). The difference = 6,000,000 kilometers
(3,720,000 miles), and its velocity is a little greater at perihelion
than at aphelion.
This second motion produces the _year_. It is accomplished in three
hundred and sixty-five days, six hours, nine minutes, nine seconds.
Such is the complete revolution of our planet round the orb of day. It
has received the name of sidereal year. But this is not how we calculate
the year in practical life. The civil year, known also as the tropical
year, is not equivalent to the Earth's revolution, because a very slow
gyratory motion, called "the precession of the equinoxes," the cycle of
which occupies 25,765 years, drags the spring equinox back some twenty
minutes in each year.
The civil year is, accordingly, three hundred and sixty-five days, five
hours, forty-eight minutes, forty-six seconds.
In order to simplify the calendar, this accumulating fraction of five
hours, forty-eight minutes, forty-six seconds (about a quarter day) is
added every four years to a bissextile year (leap-year), and thus we
have uneven years of three hundred and sixty-five, and three hundred and
sixty-six days. Every year of which the figure is divisible by four is a
leap-year. By adding a quarter day to each year, there is a surplus of
eleven minutes, fourteen seconds. These are subtracted every hundred
years by not taking as bissextile those secular years of which the
radical is not divisible by four. The year 1600 was leap-year: 1700,
1800, and 1900 were not; 2000 will be. The agreement between the
calendar and nature has thus been fairly perfect, since the
establishment of the Gregorian Calendar in 1582.
Since the terrestrial orbit measures not less than 930,000,000
kilometers (576,600,000 miles), which must be traversed in a year, the
Earth flies through Space at 2,544,000 kilometers (1,577,280 miles) a
day, or 106,000 kilometers (65,720 miles) an hour, or 29,500 meters (18
miles) per second on an average, a little faster at perihelion, a little
slower at aphelion. This giddy course, a thousand times more rapid than
the speed of an express-train, is effected without commotion, shock, or
noise. Reasoning alone enables us to divine the prodigious movement that
carries us along in the vast fields of the Infinite, in mid-heaven.
Returning to the calendar, it must be remarked in conclusion, that the
human race has not exhibited great sense in fixing the New Year on
January 1. No more disagreeable season could have been selected. And
further, as the ancient Roman names of the months have been preserved,
which in the time of Romulus began with March, the "seventh" month,
"September," is our ninth month; October (the eighth) is the tenth;
November (the ninth) has become the eleventh; and December (the tenth)
has taken the place of the twelfth. Verily, we are not hard to please!
These months, again, are unequal, as every one knows. Witness the
simple expedient of remembering the long and short months, by closing
the left hand and counting the knobs and hollows of the fist, the former
corresponding to the long months, the latter to the short: first knob =
January; first hollow, February; second knob, March; and so on.[12]
[Illustration: FIG. 63.--To find the long and short months.]
Should not the real renewal of the year coincide with the awakening of
Nature, with the spring on the terrestrial hemisphere occupied by the
greater portion of Humanity, with the date of March 21st? Should not the
months be equalized, and their names modified? Why should we not follow
the beautiful evolution dictated by the Sun and by the movement of our
planet? But our poor Earth may roll on a long time yet before its
inhabitants will become reasonable.