The multitude stationed without the doors of the Institute had made way
for those coming out, every one being eager to learn the particulars of
the session. Already the general result had in some way become known,
for immediately after the speech of the director of the Paris
observatory the rumor got abroad that the collision with the comet would
not entail consequences so serious as had been anticipated. Indeed,
large posters had just been placarded throughout Paris, announcing the
reopening of the Chicago stock exchange. This was an encouraging and
unlooked for indication of the resumption of business and the revival of
hope.
This is what had taken place. The financial magnate, whose abrupt exit
will be remembered by the reader of these pages, after rolling like a
ball from the top to the bottom row of the hemicycle, had rushed in an
aero-cab to his office on the boulevard St. Cloud, where he had
telegraphed to his partner in Chicago that new computations had just
been given out by the Institute of France, that the gravity of the
situation had been exaggerated, and that the resumption of business was
imminent; he urged, therefore, the opening of the central American
exchange at any cost, and the purchase of every security offered,
whatever its nature. When it is five o’clock at Paris it is eleven in
the morning at Chicago. The financier received the despatch from his
cousin while at breakfast. He found no difficulty in arranging for the
reopening of the exchange and invested several millions in securities.
The news of the resumption of business in Chicago had been at once made
public, and although it was too late to repeat the same game in Paris,
it was possible to prepare new plans for the morrow. The public had
innocently believed in a spontaneous and genuine revival of business in
America, and this fact, together with the satisfactory impression made
by the session of the Institute, was sufficient to rekindle the fires of
hope.
No less interest, however, was manifested in the evening session than in
that of the afternoon, and but for the exertions of an extra detachment
of the French guard it would have been impossible for those enjoying
special privileges to gain admission. Night had come, and with it the
flaming comet, larger, more brilliant, and more threatening than ever;
and if, perhaps, one-half the assembled multitude appeared somewhat
tranquillized, the remaining half was still anxious and fearful.
The audience was substantially the same, every one being eager to know
at first hand the issue of this general public discussion of the fate of
the planet, conducted by accredited and eminent scientists, whether its
destruction was to be the result of an extraordinary accident such as
now threatened it, or of the natural process of decay. But it was
noticed that the cardinal archbishop of Paris was absent, for he had
been summoned suddenly to Rome by the Pope to attend an œcumenical
council, and had left that very evening by the Paris-Rome-Palermo-Tunis
tube.
“Gentlemen,” said the president, “the translation of the despatch
received at the observatory of Gaurisankar from Mars has not arrived
yet, but we shall open the session at once, in order to hear the
important communication previously announced, which the president of the
geological society, and the permanent secretary of the academy of
meteorology, have to make to us.”
The former of these gentlemen was already at the desk. His remarks,
stenographically reproduced by a young geologist of the new school, were
as follows:
“The immense crowd gathered within these walls, the emotion I see
depicted upon every face, the impatience with which you await the
discussions yet to take place, all, gentlemen, would lead me to refrain
from laying before you the opinion which I have formed from my own study
of the problem which now excites the interest of the entire world, and
to yield the platform to those gifted with an imagination or an audacity
greater than mine. For, in my judgment, the end of the world is not at
hand, and humanity will have to wait for it several million years—yes,
gentlemen, I said _millions_, not thousands.
“You see that I am at this moment perfectly calm, and that, too, without
laying any claim to the sang froid of Archimedes, who was slain by a
Roman soldier at the siege of Syracuse while calmly tracing geometric
figures upon the sand. Archimedes knew the danger and forgot it; I do
not believe in any danger whatever.
“You will not then be surprised if I quietly submit to you the theory of
a natural end of the world, by the gradual levelling of the continents
and their slow submergence beneath the invading waters; but I shall
perhaps do better to postpone for a week this explanation, as I do not
for an instant doubt that we may all, or nearly all, reassemble here to
confer together upon the great epochs of the natural history of the
world.”
[Illustration:
ARCHIMEDES.
]
The orator paused for a moment. The president had risen: “My dear and
honorable colleague,” he said, “we are all here to listen to you.
Happily, the panic of the last few days is partially allayed, and it is
to be hoped that the night of July 13–14 will pass like its
predecessors. Nevertheless, we are more than ever interested in all
which has any bearing upon this great problem and we shall listen to no
one with greater pleasure than to the illustrious author of the classic
Treatise on Geology.”
“In that case, gentlemen,” resumed the president of the geological
society of France, “I shall explain to you what, in my judgment, will be
the natural end of the world, if, as is probable, nothing disturbs the
present course of events; for accidents are rare in the cosmical order.
“Nature does not proceed by sudden leaps, and geologists do not believe
in such revolutions or cataclysms; for they have learned that in the
natural world everything is subject to a slow process of evolution. The
geological agents now at work are permanent ones.
“The destruction of the globe by some great catastrophe is a dramatic
conception; far more so, certainly, than that of the action of the
forces now in operation, though they threaten our planet with a
destruction equally certain. Does not the stability of our continent
seem permanent? Except through the intervention of some new agency, how
is it possible to doubt the durability of this earth which has supported
so many generations before our own, and whose monuments, of the greatest
antiquity, prove that if they have come down to us in a state of ruin,
it is not because the soil has refused to support them, but because they
have suffered from the ravages of time and especially from the hand of
man? The oldest historical traditions show us rivers flowing in the same
beds as today, mountains rising to the same height; and as for the few
river-mouths which have become obstructed, the few land-slides which
have occurred here and there, their importance is so slight relatively
to the enormous extent of the continents, that it seems gratuitous
indeed to seek here the omens of a final catastrophe.
“Such might be the reasoning of one who casts a superficial and
indifferent glance upon the external world. But the conclusions of one
accustomed to scrutinize closely the apparently insignificant changes
taking place about him would be quite different. At every step, however
little skilled in observation, he will discover the traces of a
perpetual conflict between the external powers of nature and all which
rises above the inflexible level of the ocean, in whose depths reign
silence and repose. Here, the sea beats furiously against the shore,
which recedes slowly from century to century. Elsewhere, mountain masses
have fallen, engulfing in a few moments entire villages and desolating
smiling valleys. Or, the tropical rains, assailing the volcanic cones,
have furrowed them with deep ravines and undermined their walls, so that
at last nothing but ruins of these giants remain.
[Illustration:
THE SEA AT WORK.
]
[Illustration:
STREAM EROSION.
]
“More silent, but not less efficacious, has been the action of the great
rivers, as the Ganges and the Mississippi, whose waters are so heavily
laden with solid particles in suspension. Each of these small particles,
which trouble the limpidity of their liquid carrier, is a fragment torn
from the shores washed by these rivers. Slowly but surely their currents
bear to the great reservoir of the sea every atom lost to the soil, and
the bars which form their deltas are as nothing compared with what the
sea receives and hides away in its abysses. How can any reflecting
person, observing this action, and knowing that it has been going on for
many centuries, escape the conclusion that the rivers, like the ocean,
are indeed preparing the final ruin of the habitable world?
“Geology confirms this conclusion in every particular. It shows us that
the surface of the soil is being constantly altered over entire
continents by variations of temperature, by alterations of drought and
humidity, of freezing and thawing, as also by the incessant action of
worms and of plants. Hence, a continuous process of dissolution, leading
even to the disintegration of the most compact rocks, reducing them to
fragments small enough to yield at last to the attraction of gravity,
especially when this is aided by running water. Thus they travel, first
down the slopes and along the torrent beds, where their angles are worn
away and they become little by little transformed into gravel, sand and
ooze; then in the rivers which are still able, especially at
flood-times, to carry away this broken up material, and to bear it
nearer and nearer to their outlets.
“It is easy to predict what must necessarily be the final result of this
action. Gravity, always acting, will not be satisfied until every
particle subject to its law has attained the most stable position
conceivable. Now, such will be the case only when matter is in the
lowest position possible. Every surface, must therefore disappear,
except the surface of the ocean, which is the goal of every agency of
motion; and the material borne away from the crumbling continents must
in the end be spread over the bottom of the sea. In brief, the final
outcome will be the complete levelling of the land, or, more exactly,
the disappearance of every prominence from the surface of the earth.
[Illustration:
AT FLOOD-TIME.
]
“In the first place, we readily see that near the river mouths _the
final form of the dry land will be that of nearly horizontal plains_.
The effect of the erosion produced by running water will be the
formation on the water-sheds of a series of sharp ridges, succeeded by
almost absolutely horizontal plains, between which no final difference
in height greater than fifty meters can exist.
“But in no case can these sharp ridges, which, on this hypothesis, will
separate the basins, continue long; for gravity and the action of the
wind, filtration and change of temperature, will soon obliterate them.
It is thus legitimate to conclude that the end of this erosion of the
continents will be _their reduction to an absolute level_, a level
differing but little from that at the river outlets.”
The coadjutor of the archbishop of Paris, who occupied a seat in the
tribune reserved for distinguished functionaries, rose, and, as the
orator ceased speaking, added: “Thus will be fulfilled, to the letter,
the words of holy writ: ‘For the mountains shall depart and the hills be
removed.’”
“If, then,” resumed the geologist, “nothing occurs to modify the
reciprocal action of land and water, we cannot escape the conclusion
that every continental elevation is inevitably destined to disappear.
“How much time will this require?
“The dry land, if spread out in a layer of uniform thickness, would
constitute a plateau of about 700 meters altitude above the sea-level.
Admitting that its total area is 145,000,000 square kilometers, it
follows that its volume is about 101,500,000, or, in round numbers,
100,000,000 cubic kilometers. Such is the large, yet definite mass, with
which the external agencies of destruction must contend.
[Illustration:
THE RIVERS CEASE TO FLOW.
]
“Taken together, the rivers of the world may be considered as emptying,
every year, into the sea 23,000 cubic kilometers of water (in other
words, 23,000 milliards of cubic meters). This would give a volume of
solid matter carried yearly to the sea, equal to 10.43 cubic kilometers,
if we accept the established ratio of thirty-eight parts of suspended
material in 100,000 parts of water. The ratio of this amount to the
total volume of the dry land is one to 9,730,000. If the dry land were a
level plateau of 700 meters altitude, it would lose, by fluid erosion
alone, a slice of about _seven one-hundredths of a millimeter in
thickness yearly_, or one millimeter every fourteen years—say _seven
millimeters per century_.
“Here we have a definite figure, expressing the actual yearly
continental erosion, showing that, if only this erosion were to operate,
the entire mass of unsubmerged land would disappear in _less than
10,000,000 years_.
“But rain and rivers are not the only agencies; there are other factors
which contribute to the gradual destruction of the dry land:
“First, there is the erosion of the sea. It is impossible to select a
better example of this than the Britannic isles; for they are exposed,
by their situation, to the onslaught of the Atlantic, whose billows,
driven by the prevailing southwest wind, meet with no obstacle to their
progress. Now, the average recession of the English coast is certainly
less than three meters per century. Let us apply this rate to the
sea-coasts of the world, and see what will happen.
“We may proceed in two ways: First, we may estimate the loss in volume
for the entire coast-line of the world, on the basis of three
centimeters per year. To do this, we should have to know the length of
the shore-line and the mean height of the coast. The former is about
200,000 kilometers. As to the present average height of the coasts above
the sea, 100 meters would certainly be a liberal estimate. Hence, a
recession of three centimeters corresponds to an annual loss of three
cubic meters per running meter, or, for the 200,000 kilometers of
coast-line, 600,000,000 cubic meters, which is only six-tenths of a
cubic kilometer. In other words, the erosion due to the sea would only
amount to one-seventeenth that of the rivers.
“It may perhaps be objected, that, as the altitude actually increases
from the coast-line toward the interior, the same rate of recession
would, in time, involve a greater loss in volume. Is this objection well
founded? No; for the tendency of the rain and water-courses being, as we
have said, to lower the surface-level, this action would keep pace with
that of the sea.
“Again, the area of the dry land being 145,000,000 square kilometers, a
circle of equal area would have a radius of 6800 kilometers. But the
circumference of this circle would be only 40,000 kilometers; that is to
say, the sea could exercise upon the circle but one-fifth the erosive
action which it actually does upon the indented outline of our shores.
We may, therefore, admit that the erosive action of the sea upon the dry
land is _five times greater_ than it would be upon an equivalent
circular area. Certainly this estimate is a maximum; for it is logical
to suppose that, when the narrow peninsulas have been eaten away by the
sea, the ratio of the perimeter to the surface will decrease more and
more—that is, the action of the sea will be less effective. In any
event, since, at the rate of three centimeters per year, a radius of
6800 kilometers would disappear in 226,600,000 years, one-fifth of this
interval, or about 45,000,000 years, would represent the minimum time
necessary for the destruction of the land by the sea; this would
correspond to an intensity of action scarcely more than _one-fifth_ that
of the rivers and rain.
“Taken together, these mechanical causes would, therefore, involve every
year a loss in volume of twelve cubic kilometers, which, for a total of
100,000,000, would bring about the complete submergence of the dry land
in a little more than _8,000,000 years_.
[Illustration:
THE NILE.
]
“But we are far from having exhausted our analysis of the phenomena in
question. Water is not only a mechanical agent; it is also a powerful
dissolvent, far more powerful than we might suppose, because of the
large amount of carbonic acid which it absorbs either from the
atmosphere or from the decomposed organic matter of the soil. All
subterranean waters become charged with substances which it has thus
chemically abstracted from the minerals of the rocks through which it
percolates.
“River water contains, per cubic kilometer, about 182 tons of matter in
solution. The rivers of the world bring yearly to the sea, nearly _five
cubic kilometers_ of such matter. The annual loss to the dry land,
therefore, from these various causes, is _seventeen_ instead of twelve
cubic kilometers; so that the total of 100,000,000 would disappear, not
in eight, but in _a little less than six million years_.
“This figure must be still further modified. For we must not forget that
the sediment thus brought to the sea and displacing a certain amount of
water, will cause a rise of the sea-level, accelerating by just so much
the levelling process due to the wearing away of the continents.
“It is easy to estimate the effect of this new factor. Indeed, for a
given thickness lost by the plateau heretofore assumed, the sea-level
must rise by an amount corresponding to the volume of the submarine
deposit, which must exactly equal that of the sediment brought down.
Calculation shows that, in round numbers, the loss in volume will be
_twenty-four cubic kilometers_.
“Having accounted for an annual loss of twenty-four cubic kilometers,
are we now in a position to conclude what time will be necessary for the
complete disappearance of the dry land, always supposing the indefinite
continuance of present conditions?
“Certainly, gentlemen; for, after examining the objection which might be
made apropos of volcanic eruptions, we find that the latter aid rather
than retard the disintegrating process.
“We believe, therefore, that we may fearlessly accept the above estimate
of twenty-four cubic kilometers, as a basis of calculation; and as this
figure is contained 4,166,666 times in 100,000,000, which represents the
volume of the continents, we are authorized to infer that under the
_sole action of forces now in operation_, provided no other movements of
the soil occur, _the dry land will totally disappear within a period of
about 4,000,000 years_.
“But this disappearance, while interesting to a geologist or a thinker,
is not an event which need cause the present generation any anxiety.
Neither our children nor our grandchildren will be in a position to
detect in any sensible degree its progress.
“If I may be permitted, therefore, to close these remarks with a
somewhat fanciful suggestion, I will add that it would be assuredly the
acme of foresight to build today a new ark, in which to escape the
consequences of this coming universal deluge.”
[Illustration:
THE WATERS COVERING THE FACE OF THE EARTH.
]
Such was the learnedly developed thesis of the president of the
geological society of France. His calm and moderate statement of the
secular action of natural forces, opening up a future of 4,000,000
years of life, had allayed the apprehension excited by the comet. The
audience had become wonderfully tranquillized. No sooner had the
orator left the platform and received the congratulations of his
colleagues than an animated conversation began on every side. A sort
of peace took possession of every mind. People talked of the end of
the world as they would of the fall of a ministry, or the coming of
the swallows—dispassionately and disinterestedly. A fatality put off
40,000 centuries does not really affect us at all.
But the permanent secretary of the academy of meteorology had just
ascended the tribune, and every one gave him at once the strictest
attention:
“Ladies and gentlemen: I am about to lay before you a theory
diametrically opposed to that of my eminent colleague of the Institute,
yet based upon facts no less definite and a process of reasoning no less
rigorous.
“Yes, gentlemen, diametrically opposed”—
The orator, gifted with an excellent voice, had perceived the
disappointment settling upon every face.
“Oh,” he said, “opposed, not as regards the time which nature allots to
the existence of humanity, but as to the manner in which the world will
come to an end; for I also believe in a future of several million years.
“Only, instead of seeing the subsidence and complete submergence of the
land beneath the invading waters, I foresee, on the contrary, death by
drouth, and the gradual diminution of the present water supply of the
earth. Some day there will be no more ocean, no more clouds, no more
rain, no more springs, no more moisture, and vegetable as well as animal
life will perish, not by drowning, _but through lack of water_.
“On the earth’s surface, indeed, the water of the sea, of the rivers, of
the clouds, and of the springs, is decreasing. Without going far in
search of examples, I would remind you, gentlemen, that in former times,
at the beginning of the quaternary period, the site now occupied by
Paris, with its 9,000,000 of inhabitants, from Mount Saint-Germain to
Villeneuve-Saint-Georges, was almost entirely occupied by water; only
the hill of Passy at Montmartre and Pere-Lachaise, and the plateau of
Montrouge at the Panthéon and Villejuif emerged above this immense
liquid sheet. The altitudes of these plateaus have not increased, there
have been no upheavals; it is the water which has diminished in volume.
“It is so in every country of the world, and the cause is easy to
assign. A certain quantity of water, very small, it is true, in
proportion to the whole, but not negligible, percolates through the
soil, either below the sea bottoms by crevices, fissures and openings
due to submarine eruptions, or on the dry land; for not all the rain
water falls upon impermeable soil. In general, that which is not
evaporated, returns to the sea by springs, rivulets, streams and rivers;
but for this there must be a bed of clay, over which it may follow the
slopes. Wherever this impermeable soil is lacking, it continues its
descent by infiltration and saturates the rocks below. This is the water
encountered in quarries.
“This water is lost to general circulation. It enters into chemical
combination and constitutes the hydrates. If it penetrates far enough,
it attains a temperature sufficient for its transformation into steam,
and such is generally the origin of volcanoes and earthquakes. But,
within the soil, as in the open air, a sensible proportion of the water
in circulation becomes changed into hydrates, and even into oxides;
there is nothing like humidity for the rapid formation of rust. Thus
recombined, the elements of water, hydrogen and oxygen, disappear as
water. Thermal waters also constitute another interior system of
circulation; they are derived from the surface, but they do not return
there, nor to the sea. The surface water of the earth, either by
entering into new combinations, or by penetrating the lower rock-strata,
is diminishing, and it will diminish more and more as the earth’s heat
is dissipated. The heat-wells which have been dug within a hundred
years, in the neighborhood of the principal cities of the world, and
which afford the heat necessary for domestic purposes, will become
exhausted as the internal temperature diminishes. The day will come when
the earth will be cold to its center, and that day will be coincident
with an almost total disappearance of water.
[Illustration:
NO MORE WATER.
]
“For that matter, gentlemen, this is likely to be the fate of several
bodies in our solar system. Our neighbor the moon, whose volume and mass
are far inferior to those of the earth, has grown cold more rapidly, and
has traversed more quickly the phases of its astral life; its ancient
ocean-beds, on which we, today, recognize the indubitable traces of
water action, are entirely dry; there is no evidence of any kind of
evaporation; no cloud has been discovered, and the spectroscope reveals
no indication of the presence of the vapor of water. On the other hand,
the planet Mars, also smaller than the earth, has beyond a doubt reached
a more advanced phase of development, and is known not to possess a
single body of water worthy of the name of ocean, but only inland seas
of medium extent and slight depth, united with each other by canals.
That there is less water on Mars than on the earth is a fact proved by
observation; clouds are far less numerous, the atmosphere is much dryer,
evaporation and condensation take place with greater rapidity, and the
polar snows show variations, depending upon the season, much more
extensive than those which take place upon the earth. Again, the planet
Venus, younger than the earth, is surrounded by an immense atmosphere,
constantly filled with clouds. As for the large planet Jupiter, we can
only make out, as it were, an immense accumulation of vapors. Thus, the
four worlds of which we know the most, confirm, each in its own way, the
theory of a secular decrease in the amount of the earth’s water.
“I am very happy to say in this connection that the theory of a general
levelling process, maintained by my learned colleague, is confirmed by
the present condition of the planet Mars. That eminent geologist told us
a few moments ago, that, owing to the continuous action of rivers,
plains almost horizontal would constitute the final form of the earth’s
surface. That is what has already happened in the case of Mars. The
beaches near the sea are so flat that they are easily and frequently
inundated, as every one knows. From season to season hundreds of
thousands of square kilometers are alternately exposed or covered by a
thin layer of water. This is notably the case on the western shores of
the Kaiser sea. On the moon this levelling process has not taken place.
There was not time enough for it; before its consummation, the air, the
wind and the water had vanished.
“It is then certain that, while the earth is destined to undergo a
process of levelling, as my eminent colleague has so clearly explained,
it will at the same time gradually lose the water which it now
possesses. To all appearances, the latter process is now going on more
rapidly than the former. As the earth loses its internal heat and
becomes cold, crevasses will undoubtedly form, as in the case of the
moon. The complete extinction of terrestrial heat will result in
contractions, in the formation of hollow spaces below the surface, and
the contents of the ocean will flow into these hollows, without being
changed into vapor, and will be either absorbed or combined with the
metallic rocks, in the form of ferric hydrates. The amount of water will
thus go on diminishing indefinitely, and finally totally disappear.
Plants, deprived of their essential constituent, will become
transformed, but must at last perish.
“The animal species will also become modified, but there will always be
herbivora and carnivora, and the extinction of the former will involve,
inevitably, that of the latter; and at last, the human race itself,
notwithstanding its power of adaption, will die of hunger and of thirst,
on the bosom of a dried-up world.
“I conclude, therefore, gentlemen, that the end of the world will not be
brought about by a new deluge, but by the loss of its water. Without
water terrestrial life is impossible; water constitutes the chief
constituent of every living thing. It is present in the human body in
the enormous proportion of seventy per cent. Without it, neither plants
nor animals can exist. Either as a liquid, or in a state of vapor, it is
the condition of life. Its suppression would be the death-warrant of
humanity, and this death-warrant nature will serve upon us a dozen
million years hence. I will add that this will take place before the
completion of the erosion explained by the president of the geological
society of France; for he, himself, was careful to note that the period
of 4,000,000 years was dependent upon the hypothesis that the causes now
in operation continued to act as they do today; and, furthermore, he,
himself, admits that the manifestations of internal energy cannot
immediately cease. Upheavals, at various points, will occur for a long
period, and the growth of the land area from such causes as the
formation of deltas, and volcanic and coral islands, will still go on
for some time. The period which he indicated, therefore, represents only
the minimum.”
Such was the address of the permanent secretary of the academy of
meteorology. The audience had listened with the deepest attention to
both speakers, and it was evident, from its bearing, that it was fully
reassured concerning the fate of the world; it seemed even to have
altogether forgotten the existence of the comet.
“The president of the physical society of France has the floor.”
At this invitation, a young woman, elegantly dressed in the most perfect
taste, ascended the tribune.
[Illustration:
THE LADY PRESIDENT OF THE PHYSICAL SOCIETY ADDRESSING THE INSTITUTE.
]
“My two learned colleagues,” she began, without further preamble, “are
both right; for, on the one hand, it is impossible to deny that
meteorological agents, with the assistance of gravity, are working
insensibly to level the world, whose crust is ever thickening and
solidifying; and, on the other hand, the amount of water on the surface
of our planet is decreasing from century to century. These two facts may
be considered as scientifically established. But, gentlemen, it does not
seem to me that the end of the world will be due to either the
submergence of the continents, or to an insufficient supply of water for
plant and animal life.”
This new declaration, this announcement of a third hypothesis, produced
in the audience an astonishment bordering upon stupor.
“Nor do I believe,” the graceful orator hastened to add, “that the final
catastrophe can be set down to the comet, for I agree with my two
eminent predecessors, that worlds do not die by accident, but of old
age.
“Yes, doubtless, gentlemen,” she continued, “the water will grow less,
and, perhaps, in the end totally disappear; yet, it is not this lack of
water which in itself will bring about the end of things, but its
climatic consequences. The decrease in the amount of aqueous vapor in
the atmosphere will lead to a general lowering of the temperature, and
humanity will perish _with cold_.
“I need inform no one here that the atmosphere we breathe is composed of
seventy-nine per cent. of nitrogen and twenty per cent. of oxygen, and
that of the remaining one per cent. about one-half is aqueous vapor and
three ten-thousandths is carbonic acid, the remainder being ozone, or
electrified oxygen, ammonia, hydrogen and a few other gases, in
exceedingly small quantities. Nitrogen and oxygen, then, form
ninety-nine per cent. of the atmosphere, and the vapor of water one-half
the remainder.
“But, gentlemen, from the point of view of vegetable and animal life,
this half of one per cent. of aqueous vapor is of supreme importance,
and so far as temperature and climate are concerned, I do not hesitate
to assert that it is more essential than all the rest of the atmosphere.
“The heat waves, coming from the sun to the earth, which warm the soil
and are thence returned and scattered through the atmosphere into space,
in their passage through the air meet with the oxygen and nitrogen atoms
and with the molecules of aqueous vapor. These molecules are so thinly
scattered (for they occupy but the hundredth part of the space occupied
by the others), that one might infer that the retention of any heat
whatever is due rather to the nitrogen and oxygen than to the aqueous
vapor. Indeed, if we consider the atoms alone, we find two hundred
oxygen and nitrogen atoms for one of aqueous vapor. Well, this one atom
has eighty times more energy, more effective power to retain radiant
heat, than the two hundred others; consequently, a molecule of the vapor
of water is 16,000 times more effective than a molecule of dry air, in
absorbing and in radiating heat—for these two properties are
reciprocally proportional.
“To diminish by any great amount the number of these invisible molecules
of the vapor of water, is to immediately render the earth uninhabitable,
notwithstanding its oxygen; even the equatorial and tropical regions
will suddenly lose their heat and will be condemned to the cold of
mountain summits covered with perpetual snow and frost: in place of
luxurious plants, of flowers and fruits, of birds and nests, of the life
which swarms in the sea and upon the land; instead of murmuring brooks
and limpid rivers, of lakes and seas, we shall be surrounded only by ice
in the midst of a vast desert—and when I say _we_, gentlemen, you
understand we shall not linger long as witnesses, for the very blood
would freeze in our veins and arteries, and every human heart would soon
cease to beat. Such would be the consequences of the suppression of this
half hundredth part of aqueous vapor which, disseminated through the
atmosphere, beneficently protects and preserves all terrestrial life as
in a hot-house.
[Illustration:
PRIMARY VEGETATION AT THE NORTH POLE.
]
“The principles of thermodynamics prove that the temperature of space is
273° below zero. And this, gentlemen, is the more than glacial cold in
which our planet will sleep when it shall have lost this airy garment in
whose sheltering warmth it is today enwrapped. Such is the fate with
which the gradual loss of the earth’s water threatens the world, and
this death by cold will be inevitably ours, if our earthly sojourn is
long enough.
“This end is all the more certain, because not only the aqueous vapor is
diminishing, but also the oxygen and nitrogen, in brief, the entire
atmosphere. Little by little the oxygen becomes fixed in the various
oxides which are constantly forming on the earth’s surface; this is the
case also with the nitrogen, which disappears in the soil and
vegetation, never wholly regaining a gaseous state; and the atmosphere
penetrates by its weight into the land and sea, descending into
subterranean depths. Little by little, from century to century, it grows
less. Once, as for example in the early primary period, it was of vast
extent; the earth was almost wholly covered by water, only the first
granite upheaval broke the surface of the universal ocean, and the
atmosphere was saturated with a quantity of aqueous vapor immeasurably
greater than that it now holds. This is the explanation of the high
temperature of those bygone days, when the tropical plants of our time,
the tree ferns, such as the calamites, the equisetaceæ, the sigillaria
and the lepidodendrons flourished as luxuriously at the poles as at the
equator. Today, both the atmosphere and aqueous vapor have considerably
diminished in amount. In the future they are destined to disappear.
Jupiter, which is still in its primary period, possesses an immense
atmosphere full of vapors. The moon does not appear to have any at all,
so that the temperature is always below the freezing point, even in the
sunlight, and the atmosphere of Mars is sensibly rarer than ours.
“As to the time which must elapse before this reign of cold caused by
the diminution of the aqueous atmosphere which surrounds the globe, I
also would adopt the period of 10,000,000 years, as estimated by the
speaker who preceded me. Such, ladies, are the stages of world-life
which nature seems to have marked out, at least for the planetary system
to which we belong. I conclude, therefore, that the fate of the earth
will be the same as that of the moon, and that when it loses the airy
garment which now guarantees it against the loss of the heat received
from the sun, it will perish with cold.”
At this point the chancellor of the Columbian academy, who had come that
very day from Bogota by an electric air-ship to participate in the
discussion, requested permission to speak. It was known that he had
founded on the very equator itself, at an enormous altitude, an
observatory overlooking the entire planet, from which one might see both
the celestial poles at the same time, and which he had named in honor of
a French astronomer who had devoted his whole life to making known his
favorite science and to establishing its great philosophical importance.
He was received with marked sympathy and attention.
“Gentlemen,” he said, on reaching the desk, “in these two sessions we
have had an admirable resumé of the curious theories which modern
science is in a position to offer us, upon the various ways in which our
world may come to an end. The burning of the atmosphere, or suffocation
caused by the shock of the rapidly approaching comet; the submergence of
the continents in the far future beneath the sea; the drying up of the
earth as a result of the gradual loss of its water; and finally, the
freezing of our unhappy planet, grown old as the decaying and frozen
moon. Here, if I mistake not, are five distinct possible ends.
[Illustration:
PERISHING FROM COLD.
]
“The director of the observatory has announced that he does not believe
in the first two, and that in his opinion a collision with the comet
will have only insignificant results. I agree with him in every respect,
and I now wish to add, after listening attentively to the learned
addresses of my distinguished colleagues, that I do not believe in the
other three either.
“Ladies,” continued the Columbian astronomer, “you know as well as we do
that nothing is eternal. In the bosom of nature all is change. The buds
of the spring burst into flowers, the flowers in their turn become
fruit, the generations succeed each other, and life accomplishes its
mission. So the world which we inhabit will have its end as it has had
its beginning, but neither the comet, nor water, nor the lack of water
are to cause its death agony. To my mind the whole question hangs upon a
single word in the closing sentence of the very remarkable address which
has just been made by our gracious colleague, the president of the
physical society.
“The sun! Yes, here is the key to the whole problem.
“Terrestrial life depends upon its rays. I say depends upon them—life is
a form of solar energy. It is the sun which maintains water in a liquid
state, and the atmosphere in a gaseous one; without it all would be
solid and lifeless; it is the sun which draws water from the sea, the
lakes, the rivers, the moist soil; which forms the clouds and sets the
air in motion; which produces rain and controls the fruitful circulation
of the water; thanks to the solar light and heat, the plants assimilate
the carbon contained in the carbonic acid of the atmosphere, and in
separating the oxygen from the carbon and appropriating the latter the
plant performs a great work; to this conversion of solar into vital
energy, as well as to the shade of the thick-leaved trees, is due the
freshness of the forests; the wood which blazes on our hearthstones does
but render up to us its store of solar heat, and when we consume gas or
coal today, we are only setting free the rays imprisoned millions of
years ago in the forests of the primary age. Electricity itself is but a
form of energy whose original source is the sun. It is, then, the sun
which murmurs in the brook, which whispers in the wind, which moans in
the tempest, which blossoms in the rose, which trills in the throat of
the nightingale, which gleams in the lightning, which thunders in the
storm, which sings or wails in the vast symphony of nature.
“Thus the solar heat is changed into air or water currents, into the
expansive force of gases and vapors, into electricity, into woods,
flowers, fruits and muscular energy. So long as this brilliant star
supplies us with sufficient heat the continuance of the world and of
life is assured.
“The probable cause of the heat of the sun is the condensation of the
nebula in which this central body of our system had its origin. This
conversion of mechanical energy must have produced 28,000,000 degrees
centigrade. You know gentlemen, that a kilogram of coal, falling from an
infinite distance to the sun, would produce, by its impact, six thousand
times more heat than by its combustion. At the present rate of
radiation, this supply of heat accounts for the emission of thermal
energy for a period of 22,000,000 years, and it is probable that the sun
has been burning far longer, for there is nothing to prove that the
elements of the nebula were absolutely cold; on the contrary they
themselves were originally a source of heat. The temperature of this
great day-star does not seem to have fallen any; for its condensation is
still going on, and it may make good the loss by radiation.
Nevertheless, everything has an end. If at some future stage of
condensation the sun’s density should equal that of the earth, this
condensation would yield a fresh amount of heat sufficient to maintain
for 17,000,000 years the same temperature which now sustains terrestrial
life, and this period may be prolonged if we admit a diminution in the
rate of radiation, a fall of meteorites, or a further condensation
resulting in a density greater than that of the earth. But, however far
we put off the end, it must come at last. The suns which are
extinguished in the heavens, offer so many examples of the fate reserved
for our own luminary; and in certain years such tokens of death are
numerous.
“But in that long period of seventeen or twenty million years, or more,
who can say what the marvellous power of adaptation, which physiology
and paleontology have revealed in every variety of animal and vegetable
life, may not do for humanity, leading it, step by step, to a state of
physical and intellectual perfection as far above ours, as ours is above
that of the iguanodon, the stegosaurus and the compsognathus? Who can
say that our fossil remains will not appear to our successors as
monstrous as those of the dinosaurus? Perhaps the stability of
temperature of that future time may make it seem doubtful whether any
really intelligent race could have existed in an epoch subjected, as
ours is, to such erratic variations of temperature, to the capricious
changes of weather which characterize our seasons. And, who knows if
before that time some immense cataclysm, some general change may not
bury the past in new geological strata and inaugurate new periods,
quinquennial, sexennial, differing totally from the preceding ones?
“One thing is certain, that the sun will finally lose its heat; it is
condensing and contracting, and its fluidity is decreasing. The time
will come when the circulation, which now supplies the photosphere, and
makes the central mass a reservoir of radiant energy, will be obstructed
and will slacken. The radiation of heat and light will then diminish,
and vegetable and animal life will be more and more restricted to the
earth’s equatorial regions. When this circulation shall have ceased, the
brilliant photosphere will be replaced by a dark opaque crust which will
prevent all luminous radiation. The sun will become a dark red ball,
then a black one, and night will be perpetual. The moon, which shines
only by reflection, will no longer illumine the lonely nights. Our
planet will receive no light but that of the stars. The solar heat
having vanished, the atmosphere will remain undisturbed, and an absolute
calm, unbroken by any breath of air, will reign.
“If the oceans still exist they will be frozen ones, no evaporation will
form clouds, no rain will fall, no stream will flow. Perhaps, as has
been observed in the case of stars on the eve of extinction, some last
flare of the expiring torch, some accidental development of heat, due to
the falling in of the sun’s crust, will give us back for a while the
old-time sun, but this will only be the precursor of the end; and the
earth, a dark ball, a frozen tomb, will continue to revolve about the
black sun, travelling through an endless night and hurrying away with
all the solar system into the abyss of space. _It is to the extinction
of the sun that the earth will owe its death, twenty, perhaps forty
million years hence._”
The speaker ceased, and was about to leave the platform, when the
director of the academy of fine arts begged to be heard:
“Gentlemen,” he said, from his chair, “if I have understood rightly, the
end of the world will in any case result from cold, and only several
million years hence. If, then, a painter should endeavor to represent
the last day, he ought to shroud the earth in ice, and cover it with
skeletons.”
[Illustration:
A WORLD OF ICE.
]
“Not exactly,” replied the Columbian chancellor. “It is not cold which
produces glaciers,—it is _heat_.
“If the sun did not evaporate the sea water there would be no clouds,
and but for the sun there would be no wind. For the formation of
glaciers a sun is necessary, to vaporize the water and to transport it
in clouds and then to condense it. Every kilogram of vapor formed
represents a quantity of solar heat sufficient to raise five kilograms
of cast-iron to its fusing point (110°). By lessening the intensity of
the sun’s action we exhaust the glacier supply.
“So that it is not the snow, nor the glaciers which will cover the
earth, but the frozen remnant of the sea. For a long time previously
streams and rivers will have ceased to exist and every atmospheric
current will have disappeared, unless indeed, before giving up the
ghost, the sun shall have passed through one of those spasms to which we
referred a moment ago, shall have released the ice from sleep and have
produced new clouds and aerial currents, reawakened the springs, the
brooks and the rivers, and after this momentary but deceitful awakening,
shall have fallen back again into lethargy. That day will have no
morrow.”
Another voice, that of a celebrated electrician, was heard from the
center of the hemicycle.
“All these theories of death by cold,” he observed, “are plausible. But
the end of the world by fire? This has been referred to only in
connection with the comet. It may happen otherwise.
“Setting aside a possible sinking of the continents into the central
fire, brought about by an earthquake on a large scale, or some
widespread dislocation of the earth’s crust, it seems to me that,
without any collision, a superior will might arrest our planet midway in
its course and transform its motion into heat.”
“A will?” interrupted another voice. “But positive science does not
admit the possibility of miracles in nature.”
“Nor I, either,” replied the electrician. “When I say ‘will,’ I mean an
ideal, invisible force. Let me explain.
“The earth is flying through space with a velocity of 106,000 kilometers
per hour, or 29,460 meters per second. If some star, active or extinct,
should emerge from space, so as to form with the sun a sort of
electro-dynamic couple with our planet on its axis, acting upon it like
a brake—if, in a word, for any reason, the earth should be suddenly
arrested in its orbit, its mechanical energy would be changed into
molecular motion, and its temperature would be suddenly raised to such a
degree as to reduce it entirely to a gaseous state.”
“Gentlemen,” said the director of the Mont Blanc observatory, from his
chair, “the earth might perish by fire in still another manner. We have
lately seen in the sky a temporary star which, in a few weeks, passed
from the sixteenth to the fourth magnitude. This distant sun had
suddenly become 50,000 times hotter and more luminous. If such a fate
should overtake our sun, nothing living would be left upon our planet.
It is probable, from the study of the spectrum of the light emitted by
this burning star, that the cause of this sudden conflagration was the
entrance of this sun and its system into some kind of nebula. Our own
sun is travelling with a frightful velocity in the direction of the
constellation of Hercules, and may very well some day encounter an
obstacle of this nature.”
“To resume,” continued the director of the Paris observatory, “after all
we have just now heard, we see that our planet will be at a loss to
choose among so many modes of death. I have as little fear now as before
of any danger from the present comet. But it must be confessed that,
solely from the point of view of the astronomer, this poor, wandering
earth is exposed to more than one peril. The child born into this world,
and destined to reach the age of maturity, may be compared to a person
stationed at the entrance to a narrow street, one of those picturesque
streets of the sixteenth century, lined with houses at whose every
window is a marksman armed with a good weapon of the latest model. This
person must traverse the entire length of the street, without being
stricken down by the weapons levelled upon him at close range. Every
disease which lies in wait and threatens us, is on hand: dentition,
convulsion, croup, meningitis, measles, smallpox, typhoid fever,
pneumonia, enteritis, brain fever, heart disease, consumption, diabetes,
apoplexy, cholera, influenza, etc., etc., for we omit many, and our
hearers will have no difficulty in supplementing this off-hand
enumeration. Will our unhappy traveller reach the end of the street safe
and sound? If he does, it will only be to die, just the same.
[Illustration:
“LIKE A CHARGE OF SHOT UPON A MEADOW LARK.”
]
“Thus our planet pursues its way along its heavenly path, with a speed
of more than 100,000 kilometers per hour, and, at the same time, the sun
hurries it on, with all the planets, toward the constellation of
Hercules. Recapitulating what has just been said, and allowing for what
may have been omitted: it may meet a comet ten or twenty times larger
than itself, composed of deleterious gases which would render the
atmosphere irrespirable; it may encounter a swarm of uranolites, which
would have upon it the effect of a charge of shot upon a meadow lark; it
may meet in its path an invisible sun, much larger than itself, whose
shock would reduce it to vapor; it may encounter a sun which would
consume it in the twinkling of an eye, as a furnace would consume an
apple thrown into it; it may be caught in a system of electric forces,
which would act like a brake upon its eleven motions, and which would
either melt it, or set it afire, like a platinum wire in a strong
current; it may lose the oxygen which supports life; it may be blown up
like the crust over a crater; it may collapse in some great earthquake;
its dry land may disappear, in a second deluge, more universal than the
first; it may, on the contrary, lose all its water, an element essential
to its organic life; under the attraction of some passing body, it may
be detached from the sun and carried away into the cold of stellar
space; it may part, not only with the last vestige of its internal heat,
which long since has ceased to have any influence upon its surface, but
also with the protecting envelope which maintains the temperature
necessary to life; one of these days, when the sun has grown dark and
cold, it may be neither lighted, nor warmed, nor fertilized; on the
other hand, it may be suddenly scorched by an outburst of heat,
analogous to what has been observed in temporary stars; not to speak of
many other sources of accidents and mortal peril, whose easy enumeration
we leave to the geologists, paleontologists, meteorologists, physicists,
chemists, biologists, physicians, botanists, and even to the veterinary
surgeons, inasmuch as the arrival of an army of invisible microbes, if
they be but deadly enough, or a well-established epidemic, would suffice
to destroy the human race and the principal animal and vegetable
species, without working the least harm to the planet itself, from a
strictly astronomical point of view.”
Just as the speaker was uttering these last words, a voice, which seemed
to come from a distance, fell, as it were, from the ceiling overhead.
But a few words of explanation may here perhaps be desirable.
As we have said, the observatories established on the higher mountains
of the globe were connected by telephone, with the observatory of Paris,
and the sender of the message could be heard at a distance from the
receiver, without being obliged to apply any apparatus directly to the
ear. The reader doubtless recollects that, at the close of the preceding
session, a phonogram from Mt. Gaurisankar stated that a photophonic
message, which would be at once deciphered, had been received from the
inhabitants of Mars. As the translation of this cipher had not arrived
at the opening of the evening session, the bureau of communications had
connected the Institute with the observatory by suspending a
telephonoscope from the dome of the amphitheater.
The voice from above said:
“The astronomers of the equatorial city of Mars warn the inhabitants of
the earth that the comet is moving directly toward the earth with a
velocity nearly double that of the orbital velocity of Mars. Mechanical
motion to be transformed into heat, and heat into electrical energy.
Terrible magnetic storms. Move away from Italy.”
The voice ceased amid general silence and consternation. There were,
however, a few sceptics left, one of whom, editor of La Libre Critique,
raising his monocle to his right eye, had risen from the reporters desk
and had exclaimed in a penetrating voice:
“I am afraid that the venerable doctors of the Institute are the victims
of a huge joke. No one can ever persuade me that the inhabitants of
Mars—admitting that there are any and they have really sent us a
warning—know Italy by name. I doubt very much if one of them ever heard
of the Commentaries of Cæsar or the History of the Popes, especially
as”—
The orator, who was launching into an interesting dithyrambus, was at
this point suddenly squelched by the turning off of the electric lights.
With the exception of the illuminated square in the ceiling, the room
was plunged in darkness and the voice added these six words: “This is
the despatch from Mars;” and thereupon the following symbols appeared on
the plate of the telephonoscope:
[Illustration]
As this picture could only be seen by holding the head in a very
fatiguing position, the president touched a bell and an assistant
appeared, who by means of a projector and mirror transferred these
hieroglyphics to a screen on the wall behind the desk, so that every one
could readily see and analyze them at their leisure. Their
interpretation was easy; nothing indeed could be more simple. The figure
representing the comet needed no explanation. The arrow indicates the
motion of the comet towards a heavenly body, which as seen from Mars
presents phases, and sparkles like a star; this means the earth,
naturally so delineated by the Martians, for their eyes, developed in a
medium less luminous than ours, are somewhat more sensitive and
distinguish the phases of the Earth, and this the more readily because
their atmosphere is rarer and more transparent. (For us the phases of
Venus are just on the limit of visibility.) The double globe represents
Mars looking at the Kaiser sea, the most characteristic feature of
Martian geography, and indicates a velocity for the comet double the
orbital velocity, or a little less, for the line does not quite reach
the edge. The flames indicate the transformation of motion into heat;
the aurora borealis and the lightning which follow, the transformation
into electric and magnetic force. Finally, we recognize the boot of
Italy, visible from Mars, and the black spot marks the locality
threatened, according to their calculation, by one of the most dangerous
fragments of the head of the comet; while the four arrows radiating in
the direction of the four cardinal points of the compass seem to counsel
removal from the point menaced.
The photophonic message from the Martians was much longer and far more
complicated. The astronomers on Mt. Gaurisankar had previously received
several such, and had discovered that they were sent from a very
important, intellectual and scientific center situated in the equatorial
zone not far from Meridian bay. The last message, whose general meaning
is given above, was the most important. The remainder of it had not been
transmitted, as it was obscure and it was not certain that its exact
meaning had been made out.
The president rang his bell for order. He was about to sum up what had
been said, before adjourning the meeting.
“Gentlemen,” he began, “although it is after midnight, it will be of
interest, before we separate, to summarize what has been told us in
these two solemn sessions.
“The last despatch from Gaurisankar may well impress you. It seems clear
that the inhabitants of Mars are farther advanced in science than
ourselves, and this is not surprising, for they are a far older race and
have had centuries innumerable in which to achieve this progress.
Moreover, they may be much more highly organized than we are, they may
possess better eyes, instruments of greater perfection, and intellectual
faculties of a higher order. We observe, too, that their calculations,
while in accord with ours as to the collision, are more precise, for
they designate the very point which is to receive the greatest shock.
The advice to flee from Italy should therefore be followed, and I shall
at once telephone the Pope, who at this very moment is assembling the
prelates of entire Christendom.
“So the comet will collide with the earth, and no one can yet foresee
the consequences. But in all probability the disturbance will be local
and the world will not be destroyed. The carbonic-oxide is not likely to
penetrate the respirable portions of the atmosphere, but there will be
an enormous development of heat.
“As to the veritable end of the world, of all the hypotheses which today
permit us to forecast that event the most probable is the last—that
explained to us by the learned chancellor of the Columbian academy: the
life of the planet depends upon the sun; so long as the sun shines
humanity is safe, unless indeed the diminution of the atmosphere and
aqueous vapor should usher in before that time the reign of cold. In the
former case we have yet before us twenty million years of life; in the
latter only ten.
“Let us then await the night of July 13–14 without despair. I advise
those who can to pass these fête days in Chicago, or better still in San
Francisco, Honolulu or Noumea. The trans-Atlantic electric air-ships are
so numerous and well managed that millions of travellers may make the
journey before Saturday night.”
[Illustration:
THE LAST JUDGMENT.
(From the ceiling of the Sistine Chapel.)
]