Never, within the history of man, had the immense hemicycle, constructed at the end of the twentieth century, been invaded by so compact a crowd. It would have been mechanically impossible for another person to force an entrance. The amphitheater, the boxes, the tribunes, the galleries, the aisles, the stairs, the corridors, the doorways, all, to the very steps of the platform, were filled with people, sitting or standing. Among the audience were the president of the United States of Europe, the director of the French republic, the directors of the Italian and Iberian republics, the chief ambassador of India, the ambassadors of the British, German, Hungarian and Muscovite republics, the king of the Congo, the president of the committee of administrators, all the ministers, the prefect of the international exchange, the cardinal-archbishop of Paris, the director-general of telephones, the president of the council of aerial navigation and electric roads, the director of the international bureau of time, the principal astronomers, chemists, physiologists and physicians of France, a large number of state officials (formerly called deputies or senators), many celebrated writers and artists, in a word, a rarely assembled galaxy of the representatives of science, politics, commerce, industry, literature and every sphere of human activity. The platform was occupied by the president, vice-presidents, permanent secretaries and orators of the day, but they did not wear, as formerly, the green coat and chapeau or the old-fashioned sword, they were dressed simply in civil costume, and for two centuries and a half every European decoration had been suppressed; those of central Africa, on the contrary, were of the most brilliant description.

Domesticated monkeys, which for more than half a century had filled every place of service—impossible otherwise to provide for—stood at the doors, in conformity to the regulations, rather than to verify the cards of admission; for long before the hour fixed upon every place had been occupied.

The president opened the session as follows (it is needless to remind the reader that the language of the XXXVth century is here translated into that of the XIXth):

“Ladies and gentlemen: You all know the object for which we are assembled. Never, certainly, has humanity passed through such a crisis as this. Never, indeed, has this historic room of the twentieth century contained such an audience. The great problem of the end of the world has been for a fortnight the single object of discussion and study among savants. The results of their discussions and researches are now to be announced. Without further preamble I give place to the director of the observatory.”

The astronomer immediately arose, holding a few notes in his hand. He had an easy address, an agreeable voice, and a pleasant countenance. His gestures were few and his expression pleasing. He had a broad forehead and a magnificent head of curling, white hair framed his face. He was a man of learning and of culture, as well as of science, and his whole personality inspired both sympathy and respect. His temperament was evidently optimistic, even under circumstances of great peril. Scarcely had he begun to speak when the mournful and anxious faces before him became suddenly calm and reassured.

“Ladies,” he began, “I address myself first to you, begging you not to tremble in this way before a danger which may well be less terrible than it seems. I hope presently to convince you, by the arguments which I shall have the honor to lay before you, that the comet, whose approach is expected by the entire race, will not involve the total ruin of the earth. Doubtless, we may, and should, expect some catastrophe, but as for the end of the world, really, everything would lead us to believe that it will not take place in this manner. Worlds die of old age, not by accident, and, ladies, you know better than I that the world is far from being old.

“Gentlemen, I see before me representatives of every social sphere, from the highest to the most humble. Before a danger so apparent, threatening the destruction of all life, it is not surprising that every business operation should be absolutely suspended. Nevertheless, as for myself, I confess that if the bourse was not closed, and if I had never had the misfortune to be interested in speculation, I should not hesitate today to purchase securities which have fallen so low.”

This sentence was finished before a noted American Israelite—a prince of finance—director of the journal The Twenty-fifth Century, occupying a seat on one of the upper steps of the amphitheater, forced his way, one hardly knows how, through the rows of benches, and rolled like a ball to the corridor leading to an exit, through which he disappeared.

After the momentary interruption caused by this unexpected sequel to a purely scientific remark, the orator resumed:

“Our subject,” he said, “may be considered under three heads: 1. Is the collision of the comet with the earth certain? If this question is answered in the affirmative, we shall have to examine: 2. The nature of the comet, and, 3. The possible effects of a collision. I have no need to remind so intelligent an audience as this that the prophetic words ‘End of the world,’ so often heard today, signify solely ‘End of the earth,’ which moment indeed, of all others, has the most interest for us.

“If we are able to answer the first question in the negative, it will be quite superfluous to consider the other two, which would become of secondary interest.

“Unfortunately, I must admit that the calculations of the astronomers are in this case, as usual, entirely correct. Yes, the comet will strike the earth, and, doubtless, with maximum force, since the impact will be direct. The velocity of the earth is 29,400 meters per second; that of the comet is 41,660 meters, plus the acceleration due to the attraction of our planet. The initial velocity of contact, therefore, will be 72,000 meters per second. The collision, is inevitable, with all its consequences, if the impact of the comet is direct; but it will be slightly oblique. But do not for this reason, take matters so to heart. In itself the collision proves nothing. If it were announced, for example, that a railway train was to encounter a swarm of flies, this prediction would not greatly trouble the traveller. It may well be that the collision of our earth with this nebulous star will be of the same nature.

“Permit me now to examine, calmly, the two remaining questions.

“First, what is the nature of the comet? That everyone knows already; it is a gas whose principal constituent is carbonic-oxide. Invisible under ordinary conditions, at the temperature of stellar space (273 degrees below zero), this gas is in a state of vapor, even of solid particles. The comet is saturated with them. I shall not in this matter dispute in the least the discoveries of science.”

This confession deepened anew the painful expression on the faces of most of the audience, and here a long sigh was drawn.

“But, gentlemen,” resumed the astronomer, “until one of our eminent colleagues of the section of physiology, or of the academy of medicine, deigns to prove for us that the density of the comet is sufficient to admit of its penetration into our atmosphere, I do not believe that its presence is likely to exert a fatal influence upon human life. I say is likely, for it is not possible to affirm this with certainty, although the probability is very great. One might perhaps wager a million to one. In any case, only those affected with weak lungs will be victims. It will be a simple influenza, which may increase three or fivefold the daily death rate.

“If, however, as the telescope and camera agree in indicating, the nucleus contains large mineral masses, probably of a metallic nature, uranolites, measuring several kilometers in diameter, and weighing some millions of tons, one cannot but admit that the localities where these masses will fall, with the velocity referred to a moment ago, would be utterly destroyed. Let us observe, however, that three-fourths of the globe is covered with water. Here again is a contingency, not so important doubtless as the first, but, nevertheless, in our favor; these masses may perhaps fall into the sea, forming possibly new islands of foreign origin, bringing in any case elements new to science, and, it may be, germs of unknown life; Geodesy would in this case be interested, and the form and rotary movement of the earth might be modified. Let us note also that not a few deserts mark the earth’s surface. Danger exists, assuredly, but it is not overwhelming.

“Besides these masses and these gases, perhaps also the bolides of which we were speaking, coming in clouds, will kindle conflagrations at various places on the continents; dynamite, nitroglycerine, panclastite and royalite would be playthings in comparison with what may overtake us, but this does not imply a universal cataclysm; a few cities in ashes cannot arrest the history of humanity.

“You see, gentlemen, from this methodical examination of the three points before us, it follows that the danger, while it exists, and is even imminent, is not so great, so overwhelming, so certain, as is asserted. I will even say more: this curious astronomical event, which sets so many hearts beating and fills with anxiety so many minds, in the eyes of the philosopher scarcely changes the usual aspect of things. Each one of us must some day die, and this certainty does not prevent us from living tranquilly. Why should the apprehension of a somewhat more speedy death disturb the serenity of so many of us? Is the thought of our dying together so disagreeable? This should prove rather a consolation to our egotism. No, it is the thought that a stupendous catastrophe is to shorten our lives by a few days or years. Life is short, and each clings to the smallest fraction of it; it would even seem, from what one hears, that each would prefer to see the whole world perish, provided he himself survived, rather than die alone and know the world was saved. This is pure egoism. But, gentlemen, I am firm in the belief that this will be only a partial disaster, of the highest scientific importance, but leaving behind it historians to tell its story. There will be a collision, shock, and local ruin. It will be the history of an earthquake, of a volcanic eruption, of a cyclone.”

Thus spoke the illustrious astronomer. The audience appeared satisfied, calmed, tranquillized—in part, at least. It was no longer the question of the absolute end of all things, but of a catastrophe, from which, after all, one would probably escape. Whispered murmurs of conversation were to be heard; people confided to each other their impressions; merchants and politicians even seemed to have perfectly understood the arguments advanced, when, at the invitation of the presiding officer, the president of the academy of medicine was seen advancing slowly toward the tribune.

He was a tall man, spare, slender, erect, with a sallow face and ascetic appearance, and melancholy countenance—bald-headed, and wearing closely-trimmed, gray side-whiskers. His voice had something cadaverous about it, and his whole personality called to mind the undertaker rather than the physician fired with the hope of curing his patients. His estimate of affairs was very different from that of the astronomer, as was apparent from the very first word he uttered.

“Gentlemen,” said he, “I shall be as brief as the eminent savant to whom we have just listened, although I have passed many a night in analyzing, to the minutest detail, the properties of carbonic-oxide. It is about this gas that I shall speak to you, since science has demonstrated that it is the chief constituent of the comet, and that a collision with the earth is inevitable.

“These properties are terrible; why not confess it? For the most infinitesimal quantity of this gas in the air we breathe is sufficient to arrest in three minutes the normal action of the lungs and to destroy life.

“Everybody knows that carbonic-oxide (known in chemistry as CO) is a permanent gas without odor, color or taste, and nearly insoluble in water. Its density in comparison with the air is 0.96. It burns in the air with a blue flame of slight illuminating power, like a funereal fire, the product of this combustion being carbonic anhydride.

“Its most notable property is its tendency to absorb oxygen. (The orator dwelt upon these two words with great emphasis.) In the great iron furnaces, for example, carbon, in the presence of an insufficient quantity of air, becomes transformed into carbonic-oxide, and it is subsequently this oxide which reduces the iron to a metallic state, by depriving it of the oxygen with which it was combined.

“In the sunlight carbonic-oxide combines with chlorine and gives rise to an oxychlorine (COCL²)—a gas with a disagreeable, suffocating odor.

“The fact which deserves our more serious attention, is that this gas is of the most poisonous character—far more so than carbonic anhydride. Its effect upon the hemoglobin is to diminish the respiratory capacity of the blood, and even in very small doses, by its cumulative effect, hinders, to a degree altogether out of proportion to the apparent cause, the oxygenizing properties of the blood. For example: blood which absorbs from twenty-three to twenty-four cubic centimeters of oxygen per hundred volumes, absorbs only one-half as much in an atmosphere which contains less than one-thousandth part of carbonic-oxide. The one-ten-thousandth part even has a deleterious effect, sensibly diminishing the respiratory action of the blood. The result is not simple asphyxia, but an almost instantaneous blood-poisoning. Carbonic-oxide acts directly upon the blood corpuscles, combining with them and rendering them unfit to sustain life: hematosis, that is, the conversion of venous into arterial blood, is arrested. Three minutes are sufficient to produce death. The circulation of the blood ceases. The black venous blood fills the arteries as well as the veins. The latter, especially those of the brain, become surcharged, the substance of the brain becomes punctured, the base of the tongue, the larynx, the wind-pipe, the bronchial tubes become red with blood, and soon the entire body presents the characteristic purple appearance which results from the suspension of hematosis.

“But, gentlemen, the injurious properties of carbonic-oxide are not the only ones to be feared; the mere tendency of this gas to absorb oxygen would bring about fatal results. To suppress, nay, even only to diminish oxygen, would suffice for the extinction of the human species. Everyone here present is familiar with that incident which, with so many others, marks the epoch of barbarism, when men assassinated each other legally in the name of glory and of patriotism; it is a simple episode of one of the English wars in India. Permit me to recall it to your memory:

“One hundred and forty-six prisoners had been confined in a room whose only outlets were two small windows opening upon a corridor; the first effect experienced by these unfortunate captives was a free and persistent perspiration, followed by insupportable thirst, and soon by great difficulty in breathing. They sought in various ways to get more room and air; they divested themselves of their clothes; they beat the air with their hats, and finally resorted to kneeling and rising together at intervals of a few seconds; but each time some of those whose strength failed them fell and were trampled under the feet of their comrades. Before midnight, that is, during the fourth hour of their confinement, all who were still living, and who had not succeeded in obtaining purer air at the windows, had fallen into a lethargic stupor, or a frightful delirium. When, a few hours later, the prison door was opened, only twenty-three men came out alive; they were in the most pitiable state imaginable; every face wearing the impress of the death from which they had barely escaped.

“I might add a thousand other examples, but it would be useless, for doubt upon this point is impossible. I therefore affirm, gentlemen, that, on the one hand, the absorption by the carbonic-oxide of a portion of the atmospheric oxygen, or, on the other, the powerfully toxic properties of this gas upon the vital elements of the blood, alike seem to me to give to the meeting of our globe with the immense mass of the comet—in the heart of which we shall be plunged for several hours—I affirm, I repeat, that this meeting involves consequences absolutely fatal. For my part, I see no chance of escape.

“I have not spoken of the transformation of mechanical motion into heat, or of the mechanical and chemical consequences of the collision. I leave this aspect of the question to the permanent secretary of the academy of sciences and to the learned president of the astronomical society of France, who have made it the subject of important investigations. As for me, I repeat, terrestrial life is in danger, and I see not one only, but two, three and four mortal perils confronting it. Escape will be a miracle, and for centuries no one has believed in miracles.”

This speech, uttered with the tone of conviction, in a clear, calm and solemn voice, again plunged the entire audience into a state of mind from which the preceding address had, happily, released them. The certainty of the approaching disaster was painted upon every face; some had become yellow, almost green; others suddenly became scarlet and seemed on the verge of apoplexy. Some few among the audience appeared to have retained their self-possession, through scepticism or a philosophic effort to make the best of it. A vast murmur filled the room; everyone whispered his opinions to his neighbor, opinions generally more optimistic than sincere, for no one likes to appear afraid.

The president of the astronomical society of France rose in his turn and advanced toward the tribune. Instantly every murmur was hushed. Below we give the main points of his speech, including the opening remarks and the peroration:

“Ladies and gentlemen: After the statements which we have just heard, no doubt can remain in any mind as to the certainty of the collision of the comet with the earth, and the dangers attending this event. We must, therefore, expect on Saturday—”

“On Friday,” interrupted a voice from the desk of the Institute.

“On Saturday, I repeat,” continued the orator, without noticing the interruption, “an extraordinary event, one absolutely unique in the history of the world.

“I say Saturday, although the papers announce that the collision will take place on Friday, because it cannot occur before July 14th. I passed the entire night with my learned colleague in comparing the observations received, and we discovered an error in their transmission.”

This statement produced a sensation of relief among the audience; it was like a slender ray of light in the middle of a somber night. A single day of respite is of enormous importance to one condemned to death. Already chimerical projects formed in every mind; the catastrophe was put off; it was a kind of reprieve. It was not remembered that this diversion was of a purely cosmographic nature, relating to the date and not to the fact of the collision. But the least things play an important role in public opinion. So it was not to be on Friday!

“Here,” he said, going to the black-board, “are the elements as finally computed from all the observations.” The speaker traced upon the black-board the following figures:

Perihelion passage August 11, at 0h., 42m., 44s.

Longitude of perihelion, 52°, 43´, 25?.

Perihelion distance, 0.7607.

Inclination, 103°, 18´, 35?.

Longitude of ascending node, 112°, 54´, 40?.

“The comet,” he resumed, “will cross the ecliptic in the direction of the descending node 28 minutes, 23 seconds after midnight of July 14th just as the earth reaches the point of crossing. The attraction of the earth will advance the moment of contact by only thirty seconds.

“The event, doubtless, will be altogether exceptional, but I do not believe either, that it will be of so tragical a nature as has been depicted, or that it can really bring about blood poison or universal asphyxia. It will rather present the appearance of a brilliant display of celestial fire-works, for the arrival in the atmosphere of these solid and gaseous bodies cannot occur without the conversion into heat of the mechanical motion thus destroyed; a magnificent illumination of the sky will doubtless be the first phenomenon.

“The heat evolved must necessarily be very great. Every shooting star, however small, entering the upper limits of our atmosphere with a cometary velocity, immediately becomes so hot that it takes fire and is consumed. You know, gentlemen, that the earth’s atmosphere extends far into space about our planet; not without limit, as certain hypotheses declare, since the earth turns on its axis and moves about the sun: the mathematical limit is that height at which the centrifugal force engendered by the diurnal rotary motion becomes equal to the weight; this height is 6.64 times the equatorial radius of the earth, the latter being 6,378,310 meters. The maximum height of the atmosphere, therefore, is 35,973 kilometers.

“I do not here wish to enter into a mathematical discussion. But the audience before me is too well informed not to know the mechanical equivalent of heat. Every body whose motion is arrested produces a quantity of heat expressed in caloric units by mv² divided by 8338, in which m is the mass of the body in kilograms and v its velocity in meters per second. For example, a body weighing 8338 kilograms, moving with a velocity of one meter per second, would produce, if suddenly stopped, exactly one heat unit; that is to say, the quantity of heat necessary to raise one kilogram of water one degree in temperature.

“If the velocity of the body be 500 meters per second, it would produce 250,000 times as much heat, or enough to raise a quantity of water of equal mass from 0° to 30°.

“If the velocity were 5000 meters per second, the heat developed would be 5,000,000 times as great.

“Now, you know, gentlemen, that the velocity with which a comet may reach the earth is 72,000 meters per second. At this figure the temperature becomes five milliards of degrees.

“This, indeed, is the maximum and, I should add, a number altogether inconceivable; but, gentlemen, let us take the minimum, if it be your pleasure, and let us admit that the impact is not direct, but more or less oblique, and that the mean velocity is not greater than 30,000 meters per second. Every kilogram of a bolide would develop in this case 107,946 heat units before its velocity would be destroyed by the resistance of the air; in other words, it would generate sufficient heat to raise the temperature of 1079 kilograms of water from 0° to 100°—that is, from the freezing to the boiling point. A uranolite weighing 2000 kilograms would thus, before reaching the earth, develop enough heat to raise the temperature of a column of air, whose cross-section is thirty square meters and whose height is equal to that of our atmosphere, 3000°, or, to raise from 0° to 30° a column whose cross-section is 3000 square meters.

“These calculations, for the introduction of which I crave your pardon, are necessary to show that the immediate consequence of the collision will be the production of an enormous quantity of heat, and, therefore, a considerable rise in the temperature of the air. This is exactly what takes place on a small scale in the case of a single meteorite, which becomes melted and covered superficially by a thin layer of vitrified matter, resembling varnish. But its fall is so rapid that there is not sufficient time for it to become heated to the center; if broken, its interior is found to be absolutely cold. It is the surrounding air which has been heated.

“One of the most curious results of the analysis which I have just had the honor to lay before you, is that the solid masses which, it is believed, have been seen by the telescope in the nucleus of the comet, will meet with such resistance in traversing our atmosphere that, except in rare instances, they will not reach the earth entire, but in small fragments. There will be a compression of the air in front of the bolide, a vacuum behind it, a superficial heating and incandescence of the moving body, a roar produced by the air rushing into the vacuum, the roll of thunder, explosions, the fall of the denser metallic portions and the evaporation of the remainder. A bolide of sulphur, of phosphorus, of tin or of zinc, would be consumed and dissipated long before reaching the lower strata of our atmosphere. As for the shooting stars, if, as seems probable, there is a veritable cloud of them, they will only produce the effect of a vast inverted display of fire-works.

“If, therefore, there is any reason for alarm, it is not, in my opinion, because we are to apprehend the penetration of the gaseous mass of carbonic-oxide into our atmosphere, but a rise in temperature, which cannot fail to result from the transformation of mechanical motion into heat. If this be so, safety may be perhaps attained by taking refuge on the side of the globe opposed to that which is to experience the direct shock of the comet, for the air is a very bad conductor of heat.”

The permanent secretary of the academy rose in his turn. A worthy successor to the Fontenelles and Aragos of the past, he was not only a man of profound knowledge, but also an elegant writer and a persuasive orator, rising sometimes even to the highest flights of eloquence.

“To the theory which we have just heard,” he said, “I have nothing to add; I can only apply it to the case of some comet already known. Let us suppose, for example, that a comet of the dimensions of that of 1811 should collide squarely with the earth in its path about the sun. The terrestrial ball would penetrate the nebula of the comet without experiencing any very sensible resistance. Admitting that this resistance is very slight, and that the density of the comet’s nucleus may be neglected, the passage of the earth through the head of a comet of 1,800,000 kilometers in diameter, would require at least 25,000 seconds—that is, 417 minutes, or six hours, fifty-seven minutes—in round numbers, seven hours—the velocity being 120 times greater than that of a cannon-ball; and the earth continuing to rotate upon its axis, the collision would commence about six o’clock in the morning.

“Such a plunge into the cometary ocean, however rarified it might be, could not take place without producing as a first and immediate consequence, by reason of the thermodynamic principles which have been just called to your attention, a rise in temperature such that probably our entire atmosphere would take fire! It seems to me that in this particular case the danger would be very serious.

“But it would be a fine spectacle for the inhabitants of Mars, and a finer one still for those of Venus. Yes, that would indeed be a magnificent spectacle, analogous to those we have ourselves seen in the heavens, but far more splendid to our near neighbors.

“The oxygen of the air would prove insufficient to maintain the combustion, but there is another gas which physicists do not often think of, for the simple reason that they have never found it in their analyses—hydrogen. What has become of all the hydrogen freed from the soil these millions of years which have elapsed since prehistoric times? The density of this gas being one-sixteenth that of the air, it must have ascended, forming a highly rarified hydrogen envelope above our atmosphere. In virtue of the law of diffusion of gases, a large part of this hydrogen would become mixed with the atmosphere, but the upper air layers must contain a considerable portion of it. There, doubtless, at an elevation of more than one hundred kilometers, the shooting stars take fire, and the aurora borealis is lighted. Notice here that the oxygen of the air would furnish the carbon of the comet ample material during collision to feed the celestial fire.

“Thus the destruction of the world will result from the combustion of the atmosphere. For about seven hours—probably a little longer, as the resistance to the comet cannot be neglected—there will be a continuous transformation of motion into a heat. The hydrogen and the oxygen, combining with the carbon of the comet, will take fire. The temperature of the air will be raised several hundred degrees; woods, gardens, plants, forests, habitations, edifices, cities, villages, will all be rapidly consumed; the sea, the lakes and the rivers will begin to boil; men and animals, enveloped in the hot breath of the comet, will die asphyxiated before they are burned, their gasping lungs inhaling only flame. Every corpse will be almost immediately carbonized, reduced to ashes, and in this vast celestial furnace only the heart-rending voice of the trumpet of the indestructible angel of the Apocalypse will be heard, proclaiming from the sky, like a funeral knell, the antique death-song: ‘Solvet sÆculum in favilla.’ This is what may happen if a comet like that of 1811 collides with the earth.”

At these words the cardinal-archbishop rose from his seat and begged to be heard. The astronomer, perceiving him, bowed with a courtly grace and seemed to await the reply of his eminence.

“I do not desire,” said the latter, “to interrupt the honorable speaker, but if science announces that the drama of the end of the world is to be ushered in by the destruction of the heavens by fire, I cannot refrain from saying that this has always been the universal belief of the church. ‘The heavens,’ says St. Peter, ‘shall pass away with a great noise, and the elements shall meet with fervent heat, the earth also and the works that are therein shall be burned up.’ St. Paul affirms also its renovation by fire, and we repeat daily at mass his words: ‘Eum qui venturus est judicare vivos et mortuos et sÆculum per ignem.’”

“Science,” replied the astronomer, “has more than once been in accord with the prophecies of our ancestors. Fire will first devour that portion of the globe struck by the huge mass of the comet, consuming it before the inhabitants of the other hemisphere realize the extent of the catastrophe; but the air is a bad conductor of heat, and the latter will not be immediately propagated to the opposite hemisphere.

“If our latitude were to receive the first shock of the comet, reaching us, we will suppose, in summer, the tropic of Cancer, Morocco, Algeria, Tunis, Greece and Egypt would be found in the front of the celestial onset, while Australia, New Caledonia and Oceanica would be the most favored. But the rush of air into this European furnace would be such that a storm more violent than the most frightful hurricane and more formidable even than the air-current which moves continuously on the equator of Jupiter, with a velocity of 400,000 kilometers per hour, would rage from the Antipodes towards Europe, destroying everything in its path. The earth, turning upon its axis, would bring successively into the line of collision, the regions lying to the west of the meridian first blasted. An hour after Austria and Germany it would be the turn of France, then of the Atlantic ocean, then of North America, which would enter somewhat obliquely the dangerous area about five or six hours after France—that is, towards the end of the collision.

“Notwithstanding the unheard-of velocities of the comet and the earth, the pressure cannot be enormous, in view of the extremely rarified state of the matter traversed by the earth; but this matter, containing so much carbon, is combustible, and at perihelion these bodies are not infrequently seen to shine by their own as well as by reflected light: they become incandescent. What, then, must be the result of a collision with the earth? The combustion of meteorites and bolides, the superficial fusion of the uranolites which reach the earth’s surface on fire, all lead us to believe that the moment of greatest heat will be that of contact, which evidently will not prevent the massive elements forming the nucleus of the comet from crushing the localities where they fall, and perhaps even breaking up an entire continent.

“The terrestrial globe being thus entirely surrounded by the cometary mass for nearly seven hours, and revolving in this incandescent gas, the air rushing violently toward the center of disturbance, the sea boiling and filling the atmosphere with new vapors, hot showers falling from the sky-cataracts, the storm raging everywhere with electric deflagrations and lightnings, the rolling of thunder heard above the scream of the tempest, the blessed light of former days having been succeeded by the mournful and sickly gleamings of the glowing atmosphere, the whole earth will speedily resound with the funeral knell of universal doom, although the fate of the dwellers in the Antipodes will probably differ from that of the rest of mankind. Instead of being immediately consumed, they will be stifled by the vapors, by the excess of nitrogen—the oxygen having been rapidly abstracted—or poisoned by carbonic-oxide; the fire will afterwards reduce their corpses to ashes, while the inhabitants of Europe and Africa will have been burned alive.

“The well-known tendency of carbonic-oxide to absorb oxygen will doubtless prove a sentence of instant death for those farthest from the initial point of the catastrophe.

“I have taken as an example the comet of 1811; but I hasten to add that the present one appears to be far less dense.”

“Is it absolutely sure?” cried a well-known voice (that of an illustrious member of the chemical society) from one of the boxes. “Is it absolutely sure the comet is composed chiefly of carbonic-oxide? Have not the nitrogen lines also been detected in its spectrum? If it should prove to be protoxide of nitrogen, the consequence of its mixture with our atmosphere might be anÆsthesia. Every one would be put to sleep—perhaps forever, if the suspension of the vital functions were to last but a little longer than is the case in our surgical operations. It would be the same if the comet was composed of chloroform or ether. That would be an end calm indeed.

“It would be less so if the comet should absorb the nitrogen instead of the oxygen, for this partial or total absorption of nitrogen would bring about, in a few hours, for all the inhabitants of the earth—for men and women, for the young and the aged—a change of temperament, involving at first nothing disagreeable—a charming sobriety, then gayety, followed by universal joy, a feverish exultation, finally delirium and madness, terminating, in all probability, by the sudden death of every human being in the apotheosis of a wild saturnalia, an unheard-of frenzy of the senses. Would that death be a sad one?”

“The discussion remains open,” replied the secretary. “What I have said of the possible consequences of a collision applies to the direct impact of a comet like that of 1811; the one that threatens us is less colossal, and its impact will not be direct, but oblique. In common with the astronomers who have preceded me on this floor, I am inclined to believe, in this instance, in a mighty display of fire-works.”

While the orator was still speaking, a young girl belonging to the central bureau of telephones, entered by a small door, conducted by a domesticated monkey, and, darting like a flash to the seat occupied by the president, put into his hands a large, square, international envelope. It was immediately opened, and proved to be a despatch from the observatory of Gaurisankar. It contained only the following words:

“The inhabitants of Mars are sending a photophonic message. Will be deciphered in a few hours.”

“Gentlemen,” said the president, “I see several in the audience consulting their watches, and I agree with them in thinking that it will be physically impossible for us to finish in a single session this important discussion, in which eminent representatives of geology, natural history and geonomy are yet to take part. Moreover, the despatch just read will doubtless introduce new problems. It is nearly six o’clock. I propose that we adjourn to nine o’clock this evening. It is probable that we shall have received, by that time, from Asia the translation of the message from Mars. I will also beg the director of the observatory to maintain constant communication, by telephone, with Gaurisankar. In case the message is not deciphered by nine o’clock, the president of the geological society of France will open the meeting with a statement of the investigations which he has just finished, on the natural end of the world. Everybody, at this moment, is absorbingly interested in whatever relates to the question of the end of our world, whether this is dependent upon the mysterious portent now suspended above us, or upon other causes, of whatsoever nature, subject to investigation.”