University of Virginia Library

2.1. THE LAST OF THE EARTH.

Finding that they were rapidly swinging towards their proper course, and that the earth in its journey about the sun would move out of their way, they divided their power between repelling the body they had left and increasing the attraction of the moon, and then set about getting their house in order.

Bearwarden, having the largest appetite, was elected cook, the others sagely divining that labour so largely for himself would be no trial. Their small but business-like-looking electric range was therefore soon in full blast, with Bearwarden in command. It had enough current to provide heat for cooking for four hundred hours, which was an ample margin, and it had this advantage, that, no matter how much it was used, it could not exhaust the air as any other form of heat would

There were also a number of sixteen-candle-power incandescent lamps, so that when passing through the shadow of a planet, or at night after their arrival on Jupiter, their car would be brightly illuminated. They had also a good search-light for examining the dark side of a satellite, or exploring the spaces in Saturn's rings. Having lunched sumptuously on canned chicken soup, beef a la jardiniere, and pheasant that had been sent them by some of their admirers that morning, they put the bones and the glass can that had contained the soup into the double-doored partition or vestibule, placing a large sheet of cardboard to act as a wad between the scraps and the outside door. By pressing a button they unfastened the outside door, and the articles to be disposed of were shot off by the expansion of the air between the cardboard disk and the inside door; after which the outside door was drawn back to its place by a current sent through a magnet, but little power being required to reclose it with no resisting atmospheric pressure. As the electricity ran along a wire passing through a hermetically sealed opening in the floor, there was no way by which more air than that in the vestibule could escape; and as the somewhat flat space

between the doors contained less than one cubic foot, the air-pressure inside the Callisto could not be materially lessened by a few openings.

"By filling the vestibule as full as possible," said Bearwarden, "and so displacing most of its air, we shall be able to open the outside door oftener without danger of rarefaction."

The things they had discharged flew off with considerable speed and were soon out of sight; but it was not necessary for them to move fast, provided they moved at all, for, the resistance being nil, they would be sure to go beyond the range of vision, provided enough time was allowed, even if the Callisto's speed was not being increased by apergy, in which case articles outside and not affected would be quickly left behind.

The earth, which at first had filled nearly half their sky, was rapidly growing smaller. Being almost between themselves and the sun, it looked like a crescent moon; and when it was only about twenty times the size of the moon they calculated they must have come nearly two hundred thousand miles. The moon was now on what a sailor would call the starboard bow — i. e., to the right and ahead. Being

a little more than three quarters full, and only about fifty thousand miles off, it presented a splendid sight, brilliant as polished silver, and about twenty-five times as large as they had ever before seen it with the unaided eye.

It was just ten hours since they had started, and at that moment 9 A. M. in New York; but, though it was night there, the Callisto was bathed in a flood of sunlight such as never shines on earth. The only night they would have was on the side of the Callisto turned away from the sun, unless they passed through some shadow, which they intended to avoid on account of the danger of colliding with a meteor in the dark. The moon and the Callisto were moving on converging lines, the curve on which they had entered having swung them to the side nearest the earth; but they saw that their own tremendous and increasing speed would carry them in front of the moon in its nearly circular orbit. Wishing to change the direction of their flight by the moon's attraction, they shut off the power driving them from the earth, whereupon the Callisto turned its heavy base towards the moon. They were already moving at such speed that their momentum alone

would carry them hundreds of thousands of miles into space, and were then almost abreast of the earth's satellite, which was but a few thousand miles away. The spectacle was magnificent. As they looked at it through their field glasses or with the unaided eye, the great cracks and craters showed with the utmost clearness, sweeping past them almost as the landscape flies past a railway train. There was something awe-inspiring in the vast antiquity of that furrowed lunar surface, by far the oldest thing that mortal eye can see, since, while observing the ceaseless political or geological changes on earth, the face of this dead satellite, on account of the absence of air and water and consequent erosion, has remained unchanged for bygone ages, as it doubtless will for many more.

They closely watched the Callisto's course. At first it did not seem to deflect from a straight line, and they stood ready to turn on the apergetic force again, when the car very slowly began to show the effect of the moon's near pull; but not till they had so far passed it that the dark side was towards them were they heading straight for Jupiter. Then they again turned on full power and got a send-off shove

on the moon and earth combined, which increased their speed so rapidly that they felt they could soon shut off the current altogether and save their supply.

"We must be ready to watch the signals from the arctic circle," said Bearwarden. "At midnight, if the calculations are finished, the result will be flashed by the searchlight." It was then ten minutes to twelve, and the earth was already over four hundred thousand miles away. Focusing their glasses upon the region near the north pole, which, being turned from the sun, was towards them and in darkness, they waited.

"In this blaze of sunlight," said Cortlandt, "I am afraid we can see nothing."

Fortunately, at this moment the Callisto entered the moon's tapering shadow.

"This," said Ayrault, "is good luck. We could of course have gone into the shadow; but to change our course would have delayed us, and we might have lost part of the chance of increasing our speed."

"There will be no danger from, meteors or sub-satellites here," said Bearwarden, "for anything revolving about the moon at this distance would be caught by the earth."

The sun had apparently set behind the moon, and they were eclipsed. The stars shone with the utmost splendour against the dead-black sky, and the earth appeared as a large crescent, still considerably larger than the satellite to which they were accustomed. Exactly at midnight a faint phosphorescent light, like that of a glow-worm, appeared in the region of Greenland on the planet they had left. It gradually increased its strength till it shone like a long white beam projected from a lighthouse, and in this they beheld the work of the greatest search-light ever made by man, receiving for a few moments all the electricity generated by the available dynamos at Niagara and the Bay of Fundy, the steam engines, and other sources of power in the northern hemisphere. The beam lasted with growing intensity for one minute; it then spelled out with clean-cut intervals, according to the Cable Code: "23° no' 6". The southern hemisphere pumps are now raising and storing water at full blast. We have already begun to lower the Arctic Ocean."

"Victory!" shouted Bearwarden, in an ecstasy of delight. "Nearly half a degree in six months, with but one pole working. If we can add at this

rate each time to the speed of straightening already acquired, we can reverse our engines in five years, and in five more the earth will be at rest and right."

"Look!" said Ayrault, "they are sending something else." The flashes came in rapid succession, reaching far into space. With their glasses fixed upon them, they made out these sentences: "Our telescopes, in whatever part of the earth was turned towards you, have followed you since you started, and did not lose sight of you till you entered the moon's shadow. On your present course you will be in darkness till 12.16, when we shall see you again."

On receiving this last earthly message, the travellers sprang to their searchlight, and, using its full power, telegraphed back the following: "Many thanks to you for good news about earth, and to Secretary Deepwaters for lending us the navy. Result of work most glorious. Remember us to everybody. Shadow's edge approaching."

This was read by the men in the great observatories, who evidently telephoned to the arctic Signal Light immediately, for it flashed back: "Got your message perfectly. Wish you greatest luck. The

T. A. S. Co. has decked the Callisto's pedestal with flowers, and has ordered a tablet set up on the site to commemorate your celestial journey."

At that moment the shadow swept by, and they were in the full blaze of cloudless day. The change was so great that for a moment they were obliged to close their eyes. The polished sides of the Callisto shone so brightly that they knew they were easily seen. The power temporarily diverted in sending them the message then returned to the work of draining the Arctic Ocean, which, as the north pole was now returning to the sun, was the thing to do, and the travellers resumed their study of the heavenly bodies.

2.2. SPACE AND MARS.

Never before had the travellers observed the stars and planets under such favourable conditions. No air or clouds intervened, and as the Callisto did not revolve on its axis there was no necessity for changing the direction of the glasses. After an hour of this interesting work, however, as it was already late at the longitude they had left on earth, and as they knew they had many days in space before them, they prepared to go to bed. When ready, they had only to pull down the shades; for, as apergy was not applied to them, but only to the Callisto, they still looked upon the floor as down, and closed the heavy curtains to have night or darkness. They found that the side of the Callisto turned constantly towards the sun was becoming very warm, the double-toughened glass windows making it like a greenhouse; but

they consoled themselves with the thought that the sun's power on them was hourly becoming less, and they felt sure the double walls and thick upholstery would protect them almost anywhere within the solar system from the intense cold of space.

"We could easily have arranged," said Ayrault, for night and day on alternate sides of the Callisto by having strips of metal arranged spirally on the outside as on the end of an arrow. These would have started us turning as slowly as we like, since we passed through the atmosphere at a comparatively low rate of speed."

"I am afraid," said Cortlandt, "the motion, however slow, would have made us dizzy. It would be confusing to see the heavens turning about us, and it would interfere with using the glasses."

The base and one side of the Callisto had constant sunshine, while the other side and the dome were in the blackest night. This dome, on account of its shape, sky windows, and the completeness with which it could be isolated, was an ideal observatory, and there was seldom a time during their waking hours for the rest of the journey when it was not occupied by one, two, or all the observers.

"There is something marvellous," said Cortlandt, "about the condition of space. Its absolute cold is appalling, apparently because there is nothing to absorb heat; yet we find the base of this material projectile uncomfortably warm, though, should we expose a thermometer in the shade in front, we know it would show a temperature of three hundred to four hundred degrees below zero — were the instrument capable of recording it."

Artificial darkness having been obtained, the travellers were soon asleep, Bearwarden's dreams being regaled with thoughts of his company's triumph; Ayrault's, naturally, with visions of Sylvia; while Cortlandt frequently started up, thinking he had already made some great astronomical discovery.

About 9 A. M., according to seventy-fifth meridian time, the explorers awoke feeling greatly refreshed. The tank in which the liquefied oxygen was kept automatically gave off its gas so evenly that the air remained normal, while the lime contained in cups absorbed the carbon dioxide as fast as they exhaled it. They had darkened those windows through which the sun was actually pouring, for, on account of the emptiness of the surrounding ether and consequent

absence of diffusion of light, nothing but the inky blackness of space and the bright stars looked in at the rest. On raising the shades they got an idea of their speed. A small crescent, smaller than the familiar moon, accompanied by one still tinier, was all that could be seen of the earth and its satellite.

"We must," said Bearwarden, "be moving at the rate of nearly a million miles an hour, from the way we have travelled."

"We must be doing fully a million," replied Cortlandt, "for by this time we are pretty well in motion, having got a tremendous start when so near the moon, with it and the earth in line."

By steering straight for Jupiter, instead of for the place it would occupy ten days later, they knew they would swing past, for the giant planet, being in rapid motion, would advance; but they did not object to this, since it would give them a chance to examine their new world in case they wished to do so before alighting; while, if they preferred to land at once, they could easily change their course by means of the moons, the fourth, from which their car was named, being the one that they knew would be of most use.

Their tremendous speed showed them they should have time for exploration on their arrival, and that they would reach their destination sooner than they had expected. The apergetic force being applied, as we have seen, only to the Callisto, just as power in starting is exerted on a carriage or railway car and only through it to the passengers, Ayrault and his companions had no unusual sensation except loss of weight, for, when they were so far from the earth, its attraction was very slight, and no other planet was near enough to take its place. After breakfast, wishing to reach the dome, and realizing that it would be unnecessary to climb, each in turn gave a slight spring and was obliged to put up his hands to avoid striking the roof. In the cool quiet of the dark dome it was difficult to believe that only twenty feet away the sun was shining with such intensity upon the metal base as to make it too hot on the inside to touch without gloves.

The first thing that attracted their attention was the size and brilliance of Mars. Although this red planet was over forty million miles from the earth when they started, they calculated that it was less than thirty million miles from them now, or five millions

nearer than it had ever been to them before. This reduction in distance, and the clearness of the void through which they saw it, made it a splendid sight, its disk showing clearly. From hour to hour its size and brightness increased, till towards evening it looked like a small, full moon, the sun shining squarely upon it. They calculated that on the course they were moving they should pass about nine hundred thousand miles to the right or behind it, since it was moving towards their left. They were interested to see what effect the mass of Mars would have on the Callisto, and saw here a chance of still further increasing their speed. Notwithstanding its tremendous rate, they expected to see the Callisto swerve from its straight line and move towards Mars, whose orbital speed of nine hundred miles a minute they thought would take it out of the Callisto's way, so that no actual collision would occur even if their air-ship were left to her own devices.

Towards evening they noticed through their glasses that several apparently island peaks in the southern hemisphere, which was turned towards them, became white, from which they concluded that a snow-storm was in progress. The south polar

region was also markedly glaciated, though the icecap was not as extensive as either of those at the poles of the earth.

"As the Marsian winters must be fully as severe as ours," said Cortlandt, "on account of their length, the planet's distance from the sun, and the twenty-seven and a half degrees inclination of its axis, we can account for the smallness of its ice-caps only by the fact that its oceans cover but one fourth of its surface instead of three quarters, as on the earth, and there is consequently a smaller evaporation and rain and snow-fall."

They were too much interested to think of sleeping that night, and so, after dining comfortably returned to their observatory. When within four million miles of Mars the Callisto began to swerve perceptibly, its curve, as when near the moon beginning with a spiral. They swung on unconcernedly, however, knowing they could check their approach at any time. Soon Mars appeared to have a diameter ten times as great as that of the moon, and promised shortly to occupy almost one side of their sky.

We must be on the lookout for the satellites,"

said Cortlandt; "a collision with either would be worse than a wreck on a desert island."

They therefore turned their glasses in the direction of the satellites.

"Until Prof. Hall, at Washington, discovered the two satellites in 1877," he continued, "Mars was supposed to be without moons. The outer one, Deimos, is but six miles in diameter, and revolves about its primary in thirty hours and eighteen minutes, at a distance of fourteen thousand six hundred miles. As it takes but little longer to complete a revolution than Mars does to rotate on its axis, it remains in the Martial sky one hundred and thirty-two hours between rising and setting, passing through all the phases from new moon to full and back again four times; that is, it swings four times around Mars before going below the horizon. It is one of the smallest bodies discovered with a telescope. The inner one, Phobos, is considerably larger, having a diameter of about twenty miles. It is but twenty-seven hundred miles from Mars's surface, and completes its revolution in seven hours and thirty-eight minutes, which is shorter than any other known period, Jupiter's nearest moon being the next, with

eleven hours and fifty-nine minutes. It thus revolves in less than a third of the time Mars takes to rotate, and must consequently rise in the west and set in the east, as it is continually running ahead of the surface of the planet, though the sun and all the other stars rise and set on Mars in the same way as on the earth."

When about fifteen thousand miles from Mars, they sighted Deimos directly ahead, and saw that they should pass on its left — i. e., behind — for it was moving across them. The sun poured directly upon it, making it appear full and showing all its features. There were small unevennesses on the surface, apparently seventy or a hundred feet high, which were the nearest approach to mountains, and they ran in ridges or chains. There were also unmistakable signs of volcanic action, the craters being large compared with the size of the planet, but shallow. They saw no signs of water, and the blackness of the shadows convinced them there was no air. They secured two instantaneous photographs of the little satellite as the Callisto swept by, and resumed their inspection of Mars. They noticed red and brownish patches on the peaks that had that morning turned

white, from which they concluded that the show had begun to melt under the warm spring sun. This strengthened the belief they had already formed, that on account of its twenty-seven and a half degrees inclination the changes in temperature on Mars must be great and sudden. So interested were they with this, that they did not at first see a large and bright body moving rapidly on a course that converged with theirs.

"We must be ready to repel boarders," said Bearwarden, observing it for the first time and fixing his glass upon it. "That must be Phobos."

Not ten miles off they beheld Mars's inner moon, and though their own speed caused them to overtake and rush by it like a whirlwind, the satellite's rapid motion in its orbit, in a course temporarily almost parallel with theirs, served to give them a chance the better to examine it. Here the mountain ranges were considerably more conspicuous than on Deimos, and there were boulders and loose stones upon their slopes, which looked as if there might at some time have been frost and water on its surface; but it was all dry now, neither was there any air. The evidences

of volcanic action were also plainly visible, while a noticeable flattening at the poles showed that the little body had once rotated rapidly on its axis, though whether it did so still they had not time to ascertain. When abreast of it they were less than two miles distant, and they secured several instantaneous impressions, which they put aside to develop later. As the radius of Phobos's circle was far shorter than that of the parabolic curve they were making, it began to draw away, and was rapidly left behind. Applying the full apergetic force to Mars and the larger moon, they shot away like an arrow, having had their speed increased by the planet's attraction while approaching it, and subsequently by repulsion.

"Either of those," said Bearwarden, looking back at the little satellites, "would be a nice yacht for a man to explore space on. He would also, of course, need a sun to warm him, if he wished to go beyond this system, but that would not have to be a large affair — in fact, it might be smaller than the planet, and could revolve about it like a moon."

"Though a sun of that size," replied Cortlandt,

might retain its heat for the time you wished to use it, the planet part would be nothing like as comfortable as what we have here, for it would be very difficult to get enough air-pressure to breathe on so small a body, since, with its slight gravitation-pull, to secure fifteen pounds to the square inch, or anything like it, the atmosphere would have to extend thousands of miles into space, so that on a cloudy day you would be in darkness. It would be better, therefore, to have such a sun as you describe and accompany it in a yacht or private car like this, well stocked with oxygen and provisions. When passing through meteoric swarms or masses of solid matter, collision with which is the most serious risk we run, the car could follow behind its sun instead of revolving around it, and be kept from falling into it by partially reversing the attraction. As the gravitation of so small a sun would be slight, counteracting it for even a considerable time would take but little from the batteries."

"There are known to be several unclaimed masses," added Ayrault, "with diameters of a few hundred yards, revolving about the earth inside the orbit of the moon. If in some way two of these

could be brought into sufficiently violent collision, they would become luminous and answer very well; the increase in bulk as a result of the consolidation, and the subsequent heat, about serving to bring them to the required size. Whenever this sun showed spots and indications of cooling, it could be made to collide with the solid head of some comet, or small asteroid, till its temperature was again right; while if, as a result of these accretions, it became unwieldy, it could be caused to rotate with sufficient rapidity on its axis to split, and we should have two suns instead of one."

"Bravo!" said Bearwarden. "There is no limit to what can be done. The idea of our present trip would have seemed more chimerical to people a hundred years ago than this new scheme appears now."

Thus they sat and talked, or studied maps and star-charts, or the stars themselves, while the hours quickly passed and they shot through space. They had now a straight stretch of over three hundred million miles, and had to cross the orbits of innumerable asteroids on the way. The apparent size of the sun had by this time considerably decreased,

and the interior of the Callisto was no longer uncomfortably warm. They divided the day into twenty-four hours from force of habit, and drew the shades tightly during what they considered night, while Bearwarden distinguished himself as a cook.

2.3. HEAVENLY BODIES.

The following day, while in their observatory, they saw something not many miles ahead. They watched it for hours, and in fact all day, but notwithstanding their tremendous speed they came but little nearer.

"They say a stern chase is a long one," said Bearwarden; but that beats anything I have ever seen."

After a while, however, they found they were nearer, the time taken having been in part due to the deceptive distance, which was greater than they supposed.

"A comet!" exclaimed Cortlandt excitedly. "We shall really be able to examine it near."

"It's going in our direction," said Ayrault, "and at almost exactly our speed."

While the sun shone full upon it they brought their camera into play, and again succeeded in photographing a heavenly body at close range. The nucleus or head was of course turned towards the sun; while the tail, which they could see faintly, preceded it, as the comet was receding towards the cold and dark depths of space. The head was only a few miles in diameter, for it was a small comet, and was composed of grains and masses of stone and meteoric iron. Many of the grains were no larger than peas or mustard-seeds; no mass was more than four feet in diameter, and all of them had very irregular shapes. The space between the particles was never less than one hundred times their masses.

"We can move about within it," said Ayrault, as the Callisto entered the aggregation of particles, and moved slowly forward among them.

The windows in the dome, being made of toughened glass, set somewhat slantingly so as to deflect anything touching them, and having, moreover, the pressure of the inside air to sustain them, were fairly safe, while the windows in the sides and base were but little exposed. Whenever a large mass seemed dangerously near the glass, they applied an apergetic

shock to it and sent it kiting among its fellows. At these times the Callisto recoiled slightly also, the resulting motion in either being in inverse ratio to its weight. There was constant and incessant movement among the individual fragments, but it was not rotary. Nothing seemed to be revolving about anything else; all were moving, apparently swinging back and forth, but no collisions took place. When the separate particles got more than a certain distance apart they reapproached one another, but when seemingly within about one hundred diameters of each other they swung off in some other direction. The motion was like that of innumerable harp-strings, which may approach but never strike one another. After a time the Callisto seemed to become endowed with the same property that the fragments possessed; for it and they repelled one another, on a near approach, after which nothing came very near.

Much of the material was like slag from a furnace, having evidently been partly fused. Whether this heat was the result of collision or of its near approach to the sun at perihelion, they could not tell, though the latter explanation seemed most simple and probable. When at about the centre of the

nucleus they were in semi-darkness — not twilight, for any ray that succeeded in penetrating was dazzlingly brilliant, and the shadows, their own included, were inky black. As they approached the farther side and the sunlight decreased, they found that a diffused luminosity pervaded everything. It was sufficiently bright to enable them to see the dark side of the meteoric masses, and, on emerging from the nucleus in total darkness, they found the shadow stretching thousands of miles before them into space.

"I now understand," said Bearwarden, "why stars of the sixth and seventh magnitude can be seen through thousands of miles of a comet's tail. It is simply because there is nothing in it. The reason any stars are obscured is because the light in the tail, however faint, is brighter than they, and that light is all that the caudal appendage consists of, though what produces it I confess I am unable to explain. I also see why the tail always stretches away from the sun, because near by it is overwhelmed by the more powerful light; in fact, I suspect it is principally in the comet's shadow that the tail is visible. It is strange that no one ever thought of

that before, or that any one feared the earth's passing through the tail of a comet. It is obvious to me now that if there were any material substance, any gas, however rarefied, in this hairlike accompaniment, it would immediately fall to the comparatively heavy head, and surround that as a centre."

"How, then," asked Cortlandt, "do you account for the spaces between those stones? However slight gravitation might be between some of the grains, if it existed at all, or was unopposed by some other force, with sufficient time — and they have eternity — every comet would come together like a planet into one solid mass. Perhaps some similar force maintains gases in the distended tail, though I know of no such, or even any analogous manifestation on earth. If the law on which we have been brought up, that `every atom in the universe attracts every other atom,' were without exceptions or modifications, that comet could not continue to exist in its present form. Until we get some additional illustration, however, we shall be short of data with which to formulate any iconoclastic hypothesis. The source of the light,

I must admit, also puzzles me greatly. There is certainly no heat to which we can attribute it."

Having gone beyond the fragments, they applied a strong repulsion charge to the comet, creating thereby a perfect whirlpool among its particles, and quickly left it. Half an hour later they again shut off the current, as the Callisto's speed was sufficient.

For some time they had been in the belt of asteroids, but as yet they had seen none near. The morning following their experience with the comet, however, they went to their observatory after breakfast as usual, and, on pointing their glasses forward, espied a comparatively large body before them, a little to their right.

"That must be Pallas," said Cortlandt, scrutinizing it closely. "It was discovered by Olbers, in 1802, and was the second asteroid found, Ceres having been the first, in 1801. It has a diameter of about three hundred miles, being one of the largest of these small planets. The most wonderful thing about it is the inclination of its orbit — thirty-five degrees — to the plane of the ecliptic; which means that at each revolution in its orbit, it swings that much above and below the imaginary plane cutting the sun at its equator,

from which the earth and other larger planets vary but little. This no doubt is due to the near approach and disturbing attraction of some large comet, or else it was flung above or below the ordinary plane in the catastrophe that we think befell the large planet that doubtless formerly existed where we now find this swarm. You can see that its path makes a considerable angle to the plane of the ecliptic, and that it is now about crossing the line."

It soon presented the phase of a half moon, but the waviness of the straight line, as in the case of Venus and Mercury, showed that the size of the mountains must be tremendous compared with the mass of the body, some of them being obviously fifteen miles high. The intense blackness of the shadows, as on the moon, convinced them there was no trace of atmosphere.

"There being no air," said Cortlandt, "it is safe to assume there is no water, which helps to account for the great inequalities on the body's surface, since the mountains will seem higher when surrounded by dry ocean-bottom than they would if water came halfway up their sides. Undoubtedly, however, the main cause of their height is the slight effect of gravitation

on an asteroid, and the fact that the shrinking of the interior, and consequent folding of the crust in ridges, may have continued for a time after there was no longer water on the surface to cut them down.

"The temperature and condition of a body," continued Cortlandt, "seem to depend entirely on its size. In the sun we have an incandescent, gaseous star, though its spots and the colour of its rays show that it is becoming aged, or, to be more accurate, advanced in its evolutionary development. Then comes a great jump, for Jupiter has but about one fourteen-hundredth of the mass of the sun, and we expect to find on it a firm crust, and that the planet itself is at about the fourth or fifth period of development, described by Moses as days. Saturn is doubtless somewhat more advanced. The earth we know has been habitable many hundreds of thousands or millions of years, though three fourths of its surface is still covered by water. In Mars we see a further step, three fourths of its surface being land. In Mercury, could we study it better, or in the larger satellites of Jupiter or Saturn, we might find a stepping-stone from Mars to the moon, perhaps with no water, but still having air, and being habitable in all other respects.

In our own satellite we see a world that has died, though its death from an astronomical point of view is comparatively recent, while this little Pallas has been dead longer, being probably chilled through and through. >From this I conclude that all bodies in the solar system had one genesis, and were part of the same nebulous mass. But this does not include the other systems and nebulae; for, compared with them, our sun, as we have seen, is itself advanced and small beside such stars as Sirius having diameters of twelve million miles."

As they left Pallas between themselves and the sun, it became a crescent and finally disappeared.

Two days later they sighted another asteroid exactly ahead. They examined it closely, and concluded it must be Hilda, put down in the astronomies as No. 153, and having almost the greatest mean distance of any of these small bodies from the sun.

When they were so near that the disk was plainly visible to the unaided eye, Hilda passed between them and Jupiter, eclipsing it. To their surprise, the light was not instantly shut off, as when the moon occults a star, but there was evident refraction.

"By George!" said Bearwarden, "here is an asteroid that has an atmosphere."

There was no mistaking it. They soon discovered a small ice-cap at one pole, and then made out oceans and continents, with mountains, forests, rivers, and green fields. The sight lasted but a few moments before they swept by, but they secured several photographs, and carried a vivid impression in their minds. Hilda appeared to be about two hundred miles in diameter.

"How do you account for that living world," Bearwarden asked Cortlandt, "on your theory of size and longevity?"

"There are two explanations," replied Cortlandt, if the theory, as I still believe, is correct. Hilda has either been brought to this system from some other less matured, in the train of a comet, and been captured by the immense power of "Jupiter, which might account for the eccentricity of its orbit, or some accident has happened to rejuvenate it here. A collision with another minor planet moving in an orbit that crossed its own, or with the head of a large comet, would have reconverted it into a star, perhaps after it had long been cold. A comet may

first have so changed the course of one of two small bodies as to make them collide. This seems to me the most plausible theory. Over a hundred years ago the English astronomer, Chambers, wrote of having found traces of atmosphere in some of these minor planets, but it was generally thought he was mistaken. One reason we know so little about this great swarm of minor planets is, that till recently none of them showed a disk to the telescope. Inasmuch as only their light was visible, they were indistinguishable from stars, except by their slow motion. A hundred years ago only three hundred and fifty had been discovered; our photographic star-charts have since then shown the number recorded to exceed one thousand."

Comparative sizes of the planets. (From Chambers's Astronomy.)

[Description: Comparative sizes of the planets. (From Chambers's Astronomy.) ]

2.4. PREPARING TO ALIGHT.

That afternoon Ayrault brought out some statistical tables he had compiled from a great number of books, and also a diagram of the comparative sizes of the planets. "I have been not a little puzzled at the discrepancies between even the best authors," he said, "scarcely any two being exactly alike, while every decade has seen accepted theories radically changed." Saying which, he spread out the result of his labours (shown on the following pages), which the three friends then studied.

"You see," Ayrault explained, "on Jupiter we shall need our apergetic outfits to enable us to make long marches, while on Saturn they will not be necessary, the increase in our weight as a result of that planet's size being considerably less than the usual load carried by the Roman soldier."

• Mean distance Semimajor
• Planets from axis of orbit, Inclination
• sun in earth's Eccentricity of orbit Light at Light at Heat,
• millions distance of orbit. to ecliptic. perihelion. aphelion. earth as 1.
• of miles. as 1.
• Mercury................36.0 0.387 0.2056 7° 0' 8" 10.58 4.59 6.67
• Venus..................67.2 0.723 0.0068 3° 23' 35" 1.94 1.91 1.91
• The Earth..............92.9 1.000 0.068 0° 0' 0" 1.03 0.997 1.00
• Mars...................141.5 1.524 0.0933 1° 51' 2" 0.52 0.360 1.43
• Asteroids..............204.4 to 2.200 0.4 to 5° to 35°
• 325.2 to 3.500 0.34
• Jupiter................483.3 5.203 0.0483 1° 18' 41" 0.04 0.034 0.037
• Saturn.................886.0 9.539 0.0561 2° 29' 40" 0.012 0.0099 0.011
• Uranus.................1781.9 19.183 0.0463 0° 46' 20" 0.0027 0.0025 0.003
• Neptune................2791.6 30.055 0.0090 1° 47' 2" 0.0011 0.0011 0.001

• MOVEMENT IN ORBIT.
• — Velocity, Mean diameter Surface Volume Mass
• Period of Orbital earth's in miles. compared compared Compared
• revolution velocity as 1. with earth with earth with earth
• Planets in years in miles as 1. as 1. as 1.
• and days. per second.
• Mercury...............0.88 23 to 35 1.6 3,000 0.14 0.056 0.13
• Venus.................0.224 1/2 21.9 1.17 7,700 0.94 0.92 0.78
• The Earth.............1.00 18.5 1.0 7,918 1.00 1.00 1.00
• Mars..................1.88 15.0 0.81 4,230 0.28 0.139 0.124
• Asteroids.............3.29 .... .... From a few
• to 6.56 miles to 300
• Jupiter...............11.86 8.1 0.44 86,500 118.3 1309.000 316.0
• Saturn................29.46 6.0 0.32 71,000 80.4 760.0 95.0
• Uranus................84.02 4.2 0.23 31,900 16.3 65.0 14.7
• Neptune...............164.78 3.4 0.18 34,800 19.3 90.0 17.1

• DENSITY FORCE OF GRAVITY AT
• SURFACE OF PLANET.
• Compared Compared Compared Bodies Inclination
• Planets with with with fall in Length of Length of seasons. of axis.
• earth water earth one day.
• as 1. as 1. as 1. second.
• Mercury.........1.24 7.17 0.85 13.7
• hrs. min. sec.
• Venus...........0.92 5.21 0.83 13.4 23 21 22 .......................... 53+
• Spring, 93 terrestrial days
• The Earth.......1.00 5.67 1.00 16.09 ............ Summer, 93 " " 23 1/2
• Autumn, 90
• Winter, 89
• Spring, 191 Martial days
• Mars............0.96 2.54 0.38 6.2 24 37 23 Summer, 181 " " 27 1/2
• Autumn, 149 " "
• Winter, 147 " "
• Asteroids.......
• Jupiter.........0.22 1.29 2.55 40.98 9 55 28 .................. 1 1/2
• Saturn......... 0.13 0.63 1.15 18.53 10 29 17 .................. 27
• Uranus........ 0.18 1.41 0.91 14.6 ............ .................. 102 (?)
• Neptune....... 0.20 0.94 0.88 14.2

"I do not imagine," said Cortlandt, "we should long be troubled by gravitation without our apergetic outfits even on Jupiter, for, though our weight will be more than doubled, we can take off one quarter of the whole by remaining near the equator, their rapid rotation having apparently been given providentially to all the large planets. Nature will adapt herself to this change, as to all others, very readily. Although the reclamation of the vast areas of the North American Arctic Archipelago, Alaska, Siberia, and Antarctic Wilkes Land, from the death-grip of the ice in which they have been held will relieve the pressure of population for another century, at the end of that time it will surely be felt again; it is therefore a consolation to feel that the mighty planets Jupiter and Saturn, which we are coming to look upon as our heritage, will not crush the life out of any human beings by their own weight that may alight upon them."

Before going to bed that evening they decided to be up early the next day, to study Jupiter, which was already a brilliant object.

The following morning, on awakening, they went at once to their observatory, and found that Jupiter's

disk was plainly visible to the naked eye, and before night it seemed as large as the full moon.

They then prepared to check the Callisto's headlong speed, which Jupiter's attraction was beginning to increase. When about two million miles from the great planet, which was considerably on their left, they espied Callisto ahead and slightly on their right, as Deepwaters had calculated it would be. Applying a mild repulsion to this — which was itself quite a world, with its diameter of over three thousand miles, though evidently as cold and dead as the earth's old moon — they retarded their forward rush, knowing that the resulting motion towards Jupiter would be helped by the giant's pull. Wishing to be in good condition for their landing, they divided the remainder of the night into watches, two going to sleep at a time, the man on duty standing by to control the course and to get photographic negatives, on which, when they were developed, they found two crescent-shaped continents, a speckled region, and a number of islands. By 7 A. M., according to Eastern standard time, they were but fifty thousand miles from Jupiter's surface, the gigantic globe filling nearly one side of the sky. In preparation for a sally, they got their guns

and accoutrements ready, and then gave a parting glance at the car. Their charge of electricity for developing the repulsion seemed scarcely touched, and they had still an abundant supply of oxygen and provisions. The barometer registered twenty-nine inches, showing that they had not lost much air in the numerous openings of the vestibule. The pressure was about what would be found at an altitude of a few hundred feet, part of the rarefaction being no doubt due to the fact that they did not close the windows until at a considerable height above Van Cortlandt Park.

They saw they should alight in a longitude on which the sun had just risen, the rocky tops of the great mountains shining like helmets in its rays. Soon they felt a sharp checking of their forward motion, and saw, from the changed appearance of the stars and the sun, that they had entered the atmosphere of their new home.

Not even did Columbus, standing at the prow of the Santa Maria, with the New World before him, feel the exultation and delight experienced by these latter-day explorers of the twenty-first century. Their first adventures on landing the reader already knows.

2.5. EXPLORATION AND EXCITEMENT.

When they awoke, the flowers were singing with the volume of a cathedral organ, the chant rising from all around them, and the sun was already above the horizon. Finding a deep natural spring, in which the water was at about blood-heat, they prepared for breakfast by taking a bath, and then found they had brought nothing to eat.

"It was stupid of us not to think of it," said Bearwarden, "yet it will be too much out of our way to return to the Callisto."

"We have two rifles and a gun," said Ayrault, "and have also plenty of water, and wood for a fire. All we need is game."

"The old excuse, that it has been already shot out, cannot hold here," said Cortlandt.

"Seeing that we have neither wings nor pneumatic

legs, and not knowing the advantage given us by our rifles," added Bearwarden, "it should not be shy either. So far," he continued, "we have seen nothing edible, though just now we should not be too particular; but near a spring like this that kind must exist."

"The question is," said the professor, "whether the game like warm water. If we can follow this stream till it has been on the surface for some time, or till it spreads out, we shall doubtless find a huntsman's paradise."

"A bright idea," said Bearwarden. "Let's have our guns ready, and, as old Deepwaters would say, keep our weather eye open."

The stream flowed off in a southeasterly direction, so that by following it they went towards the volcanoes.

"It is hard to realize," said the professor, that those mountains must be several hundred miles away, for the reason that they are almost entirely above the horizon. This apparent flatness and wide range of vision is of course the result of Jupiter's vast size. With sufficiently keen sight, or aided by a good glass, there is no reason why one should

not see at least five hundred miles, with but a slight elevation."

"It is surprising," said Ayrault, "that in what is evidently Jupiter's Carboniferous period the atmosphere should be so clear. Our idea has been that at that time on earth the air was heavy and dense."

"So it was, and doubtless is here," replied Cortlandt; "but you must remember that both those qualities would be given it by carbonic-acid gas, which is entirely invisible and transparent. No gas that would be likely to remain in the air would interfere with sight; water vapour is the only thing that could; and though the crust of this planet, even near the surface, is still hot, the sun being so distant, the vapour would not be, raised much. By avoiding low places near hot springs, we shall doubtless have very nearly as clear an atmosphere as on earth. What does surprise me is the ease with which we breathe. I can account for it only by supposing that, the Carboniferous period being already well advanced, most of the carbonic acid is already locked up in the forests or in Jupiter's coal-beds."

"How, asked Bearwarden, "do you account for the `great red spot' that appeared here in 1878,

lasted several years, and then gradually faded? It was taken as unmistakable evidence that Jupiter's atmosphere was filled with impenetrable banks of cloud. In fact, you remember many of the old books said we had probably never seen the surface."

"That has puzzled me very much," replied Cortlandt, "but I never believed the explanation then given was correct. The Carboniferous period is essentially one of great forest growth; so there would be nothing out of the way in supposing the spot, notwithstanding its length of twenty-seven thousand miles and its breadth of eight thousand miles, to have been forest. It occurred in what would correspond to the temperate region on earth. Now, though the axis of this planet is practically straight, the winds of course change their direction, and so the temperature does vary from day to day. What is more probable than that, owing perhaps to a prolonged norther or cold spell, a long strip of forest lying near the frost line was brought a few degrees below it, so that the leaves changed their colours as they do on earth? It would, it seems to me, be enough to give the surface a distinct colour; and the fact that the spot's greatest length was east and west,

or along the lines of latitude, so that the whole of that region might have been exposed to the same conditions of temperature, strengthens this hypothesis. The strongest objection is, that the spot is said to have moved; but the motion — five seconds — was so slight that it might easily have been an error in observation, or the first area affected by the cold may have been enlarged on one side. It seems to me that the stability the spot did have would make the cloud theory impossible on earth, and much more so here, with the far more rapid rotation and more violent winds. It may also have been a cloud of smoke from a volcano in eruption, such as we saw on our arrival, though it is doubtful whether in that case it would have remained nearly stationary while going through its greatest intensity and fading, which would look as though the turned leaves had fallen off and been gradually replaced by new ones; and, in addition to this, the spot since it was first noticed has never entirely disappeared, which might mean a volcanic region constantly emitting smoke, or that the surface, doubtless from some covering whose colour can change, is normally of a different shade from the surrounding region. In any case, we have as yet seen nothing that would indicate a permanently clouded atmosphere."

Though they had walked a considerable distance, the water was not much cooled; and though the stream's descent was so slight that on earth its current would have been very slow, here it rushed along like a mountain torrent, the reason, of course, being that a given amount of water on Jupiter would depress a spring balance 2.55 times as much as on the earth.

"It is strange," said Ayrault, "that, notwithstanding its great speed, the water remains so hot; you would think its motion would cool it."

"So it does," answered the professor. "It of course cools considerably more in a given period — as, for instance, one minute — than if it were moving more slowly, but on account of its speed it has been exposed to the air but a very short time since leaving the spring."

Just before them the stream now widened into a narrow lake, which they could see was straight for some distance.

"The fact is," said Bearwarden, "this water seems in such haste to reach the ocean that it turns

neither to right nor to left, and does not even seem to wish to widen out."

As the huge ferns and palms grew to the water's edge, they concluded the best way to traverse the lake would be on a raft. Accordingly, choosing a large overhanging palm, Bearwarden and Ayrault fired each an explosive ball into its trunk, about eighteen inches from the ground. One round was enough to put it in the water, each explosion removing several cubic feet of wood. By repeating this process on other trees they soon had enough large timber for buoyancy, so that they had but to superimpose lighter cross-logs and bind the whole together with pliable branches and creepers to form a substantial raft. The doctor climbed on, after which Bearwarden and Ayrault cast off, having prepared long poles for navigating. With a little care they kept their bark from catching on projecting roots, and as the stream continued to widen till it was about one hundred yards across, their work became easy. Carried along at a speed of two or three miles an hour, they now saw that the water and the banks they passed were literally alive with reptiles and all sorts of amphibious creatures, while winged lizards sailed from every over

hanging branch into the water as they approached. They noticed also many birds similar to storks and cranes, about the size of ostriches, standing on logs in the water, whose bills were provided with teeth.

"We might almost think we were on earth," said Ayrault, "from the looks of those storks standing on one leg, with the other drawn up, were it not for their size."

"How do you suppose they defend themselves," asked Bearwarden, "from the snakes with which the water is filled?"

"I suspect they can give a pretty good account of themselves," replied Cortlandt, "with those teeth. Besides, with only one leg exposed, there is but a very small object for a snake to strike at. For their number and size, I should say their struggle for existence was comparatively mild. Doubtless non-poisonous, or, for that matter, poisonous snakes, form a great part of their diet."

On passing the bend in the lake they noticed that the banks were slightly higher, while palms, pine-trees, and rubber plants succeeded the ferns. In the distance they now heard a tremendous crashing, which grew louder as the seconds passed. It finally

sounded like an earthquake. Involuntarily they held their breath and grasped their weapons. Finally, at some distance in the woods they saw a dark mass moving rapidly and approaching the river obliquely. Palms and pine-trees went down before it like straws, while its head was continually among the upper branches. As the monster neared the lake, the water at the edges quivered, showing how its weight shook the banks at each stride, while stumps and tree-trunks on which it stepped were pressed out of sight in the ground. A general exodus of the other inhabitants from his line of march began; the moccasins slid into the water with a low splash, while the boa-constrictors and the tree-snakes moved off along the ground when they felt it tremble, and a number of night birds retreated into the denser woods with loud cries at being so rudely disturbed. The huge beast did not stop till he reached the bank, where lie switched his tail, raised his proboscis, and sniffed the air uneasily, his height being fully thirty feet and his length about fifty. On seeing the raft and its occupants, he looked at them stupidly and threw back his head.

He seems to be turning up his nose at us,"

said Bearwarden. "All the same, he will do well for breakfast."

As the creature moved, his chest struck a huge overhanging palm, tearing it off as though it had been a reed. Brushing it aside with his trunk, he was about to continue his march, when two rifle reports rang out together, rousing the echoes and a number of birds that screeched loudly.

2.6. MASTODON AND WILL-O'-THE WISPS.

Bearwarden's bullet struck the mammoth in the shoulder, while Ayrault's aim was farther back. As the balls exploded, a half-barrelful of flesh and hide was shot from each, leaving two gaping holes. Instantly he rushed among the trees, making his course known for some time by his roars. As he turned, Bearwarden fired again, but the hall flew over him, blowing off the top of a tree.

"Now for the chase!" said Ayrault. "There would be no excuse for losing him."

Quickly pushing their raft to shore and securing it to the bank, the three jumped off. Thanks to their rubber boots and galvanic outfits which automatically kept them charged, they were as spry as they would have been on earth. The ground all about them, and in a strip twelve feet wide where the

mammoth had gone, was torn up, and the vegetation trodden down. Following this trail, they struck back into the woods, where in places the gloom cast by the thick foliage was so dense that there was a mere twilight, startling as they went numbers of birds of grey and sombre plumage, whose necks and heads, and the sounds they uttered, were so reptilian that the three terrestrials believed they must also possess poison fangs.

"The most highly developed things we have seen here," said Bearwarden, "are the flowers and fireflies, most of the birds and amphibians being simply loathsome."

As they proceeded they found tracks of blood, which were rapidly attracting swarms of the reptile birds and snakes, which, however, as a rule, fled at their approach.

"I wonder what can have caused that mammoth to move so fast, and to have seemed so ill at ease?" said the doctor. "His motive certainly was not thirst, for he did not approach the water in a direct line, neither did he drink on reaching it. One would think nothing short of an earthquake or a land-slide could trouble him."

"There can be no land-slide here," said Ayrault, for the country is too flat."

"And after yesterday's eruptions," added Bearwarden, "it would seem as though the volcanoes could have scarcely enough steam left to make trouble."

The blood-tracks, continuing to become fresher, showed them they were nearing the game, when suddenly the trail took a sharp turn to the right, even returning towards the lake. A little farther it took another sharp turn, then followed a series of doublings, while still farther the ground was completely denuded of trees, its torn-up and trampled condition and the enormous amount of still warm blood showing how terrific a battle had just taken place.

While they looked about they saw what appeared to be the trunk of a tree about four feet in diameter and six feet long, with a slight crook. On coming closer, they recognized in it one of the forefeet of the mammoth, cut as cleanly as though with a knife from the leg just above the ankle, and still warm. A little farther they found the huge trunk cut to slivers, and, just beyond, the body of the unfortunate beast with three of its feet gone, and the thick hide

cut and slashed like so much paper. It still breathed, and Ayrault, who had a tender heart, sent an explosive ball into its skull, which ended its suffering.

The three hunters then surveyed the scene. The largest and most powerful beast they had believed could exist lay before them dead, not from the bite of a snake or any other poison, but from mechanical injuries of which those they had inflicted formed but a very small part, and literally cut to pieces.

"I am curious to see the animal," said Cortlandt, "capable of doing this, though nothing short of dynamite bombs would protect us from him."

"As he has not stopped to eat his victim," said Bearwarden, "it is fair to suppose he is not carnivorous, and so must have had some other motive than hunger in making the attack; unless we can suppose that our approach frightened him away, which, with such power as he must possess, seems unlikely. Let us see," he continued, "parts of two legs remain unaccounted for. Perhaps, on account of their shape, he has been able the more easily to carry or roll them off, for we know that elephant foot makes a capital dish."

"From the way you talk," said Cortlandt, "one

would suppose you attributed this to men. The Goliath we picture to ourselves would be a child compared to the man that could cut through these legs, though the necessity of believing him to have merely great size does not disprove his existence here. I think it probable we shall find this is the work of some animal with incisors of such power as it is difficult for us to conceive of."

"There is no indication here of teeth," said Bearwarden, "each foot being taken off with a clean cut. Besides, we are coming to believe that man existed on earth during the greater part, if not the whole, of our Carboniferous period."

We must reserve our decision pending further evidence, said Cortlandt.

"I vote we take the heart," said Ayrault, "and cook it, since otherwise the mammoth will be devoured before our eyes."

While Bearwarden and Ayrault delved for this, Cortlandt, with some difficulty, parted the mammoth's lips and examined the teeth. "From the conical projections on the molars," said he, "this should be classed rather as a mastodon than as a mammoth."

When the huge heart was secured, Bearwarden arranged slices on sharpened sticks, while Ayrault set about starting a fire. He had to use Cortlandt's gun to clear the dry wood of snakes, which, attracted doubtless by the dead mastodon, came in such numbers that they covered the ground, while huge pterodactyls, more venomous-looking than the reptiles, hovered about the opening above.

Arranging a double line of electric wires in a circle about the mastodon and themselves, they sat down and did justice to the meal, with appetites that might have dismayed the waiting throng. Whenever a snake's head came in contact with one wire, while his tail touched the other, he gave a spasmodic leap and fell back dead. If he happened to fall across the wires, lie immediately began to sizzle, a cloud of smoke arose, and lie was reduced to ashes.

"Any time that we are short of mastodon or other good game," said Ayrault, "we need not hunger if we are not above grilled snake."

All laughed at this, and Bearwarden, drawing a whiskey-flask from his pocket, passed it to his friends.

When we rig our fishing-tackle," he continued, and have fresh fish for dinner, an entree of rattle

snake, roast mastodon for the piece de resistance, and begin the whole with turtle soup and clams, of which there must be plenty on the ocean beach, we shall want to stay here the rest of our lives."

"I suspect we shall have to," replied Ayrault for we shall become so like Thanksgiving turkeys that the Callisto's door will be too small for us."

While they sat and talked, the flowers and plants about them softly began their song, and, as a visual accompaniment, the fire-flies they had not before noticed twinkled through the forest.

"My goodness! " exclaimed Cortlandt, "how time goes here! We started to get breakfast, and now it's growing dark."

Hastily cutting some thick but tender slices from the mastodon, and impaling them with the remains of the heart on a sharpened stake, they took up the wires, and the battery that had been supplying the current, and retraced their steps by the way they had come. Their rubber-lined cowhide boots protected them from all but the largest snakes, and as these were for the most part already enjoying their gorge, they trampled with impunity on those that remained in their path. When they had covered about half

the distance to the raft, a huge boa-constrictor, which they had mistaken for a branch, fell upon Cortlandt, pinioning his arms and bearing him to the ground. Dropping their loads, Bearwarden and Ayrault threw themselves upon the monster with their hunting-knives with such vim that in a few seconds it beat a hasty retreat, leaving, as it did so, a wake of phosphorescent light.

"Are you hurt?" asked Bearwarden, helping him up.

"Not in the least," replied Cortlandt. "What surprises me is that I am not. The weight of that boa-constrictor would be very great on earth, and here I should think it would be simply crushing."

Groping their way through the rapidly growing darkness, they reached the raft without further adventure, and, once on the lake, had plenty of light. Two moons, one at three quarters and the other full, shone brightly, while the water was alive with gymnotuses and other luminous creatures. Sitting and living upon the cross-timbers, they looked up at the sky. The Great Bear and the north star had exactly the same relation to each other as when seen from the earth, while the other constellations and the

Milky Way looked identically as when they had so often gazed at them before, and some idea of the immensity of space was conveyed to them. Here was no change; though they had travelled three hundred and eighty million miles, there was no more perceptible difference than if they had not moved a foot. Perhaps, they thought, to the telescopes — if there are any — among the stars, the sun was seen to be accompanied by two small, dark companions, for Jupiter and Saturn might be visible, or perhaps it seemed merely as a slightly variable star, in years when sun-spots were numerous, or as the larger planets in their revolutions occasionally intercepted a part of its light. As they floated along they noticed a number of what they took to be Will-o'-the-wisps. Several of these great globules of pale flame hovered about them in the air, near the surface of the water, and anon they rose till they hung above the trees, apparently having no forward or horizontal motion except when taken by the gentle breeze, merely sinking and rising.

"How pretty they are!" said Cortlandt, as they watched them. "For bodies consisting of marsh gas, they hold together wonderfully."

Presently one alighted on the water near them. It was considerably brighter than any glow-worm, and somewhat larger than an arc lamp, being nearly three feet in diameter; it did not emit much light, but would itself have been visible from a considerable distance. Cortlandt tried to touch it with a raft-pole, but could not reach far enough. Presently a large fish approached it, swimming near the surface of the water. When it was close to the Jack-o'-lantern, or whatever it was, there was a splash, the fish turned up its white under side, and, the breeze being away from the raft, the fire-ball and its victim slowly floated off together. There were frequently a dozen of these great globules in sight at once, rising and descending, the observers noticing one peculiarity, viz., that their brightness increased as they rose, and decreased as they sank.

About two and a half hours after sunset, or midnight according to Jupiter time, they fell asleep, but about an hour later Cortlandt was awakened by a weight on his chest. Starting up, he perceived a huge white-faced bat, with its head but a few inches from his. Its outstretched wings were about eight feet across, and it fastened its sharp claws upon him.

Seizing it by the throat, he struggled violently. His companions, awakened by the noise, quickly came to his rescue, grasping him just as he was in danger of being dragged off the raft, and in another moment Bearwarden's knife had entered the creature's spine.

"This evidently belongs to the blood-sucking species," said Cortlandt. "I seem to be the target for all these beasts, and henceforth shall keep my eyes open at night."

As day would break in but little over an hour, they decided to remain awake, and they pushed the dead bat overboard, where it was soon devoured by fishes. A chill had come upon the air, and the incessant noise of the forms of life about them had in a measure ceased.

Cortlandt passed around a box of quinine as a preventive against malaria, and again they lay back and looked at the stars. The most splendid sight in their sky now was Saturn. At the comparatively short distance this great planet was from them, it cast a distinct shadow, its vast rings making it appear twice its real size. With the first glimmer of dawn, the fire-balls descended to the surface of the

water and disappeared within it, their lights going out. With a suddenness to which the explorers were becoming accustomed, the sun burst upon them, rising as perpendicularly as at the earth's equator, and more than twice as fast, having first tinged the sky with the most brilliant hues.

The stream had left the forest and swamp, and was now flowing through open country between high banks. Pushing the raft ashore, they stepped off on the sand, and, warming up the remains of the mastodon's heart, ate a substantial breakfast.

While washing their knives in the stream preparatory to leaving it — for they wished to return to the Callisto by completing the circle they had begun — they noticed a huge flat jelly-fish in shallow water. It was so transparent that they could see the sandy bottom through it. As it seemed to be asleep, Bearwarden stirred up the water around it and poked it with a stick. The jelly-fish first drew itself together till it touched the surface of the water, being nearly round, then it slowly left the stream and rose till it was wholly in the air, and, notwithstanding the sunlight, it emitted a faint glow.

"Ah!" exclaimed Bearwarden, "here we have

one of our Jack-o'-lanterns. Let us see what it is going to do."

"It is incomprehensible to me," said Cortlandt, how it maintains itself; for it has neither wings nor visible means of support, yet, as it was able to immerse itself in the stream, thereby displacing a volume of liquid equivalent to its bulk, it must be at least as heavy as water."

The jelly-fish remained poised in the air until directly above them, when it began to descend.

"Stand from under!" cried Bearwarden, stepping back. "I, for one, should not care to be touched."

The great soft mass came directly over the spot on which they had been standing, and stopped its descent about three feet from the ground, parallel to which it was slowly carried by the wind. A few yards off, in the direction in which it was moving, lay a long black snake asleep on the sand. When directly over its victim the jelly globule again sank till it touched the middle of the reptile's back. The serpent immediately coiled itself in a knot, but was already dead. The jellyfish did not swallow, but completely surrounded its prey, and again rose in the air, with the snake's black body clearly visible within it.

Our Will-o'-the-wisp is prettier by night than by day," said Bearwarden. "I suggest that we investigate this further."

"How?" asked Cortlandt.

"By destroying its life," replied Bearwarden. Give it one barrel from your gun, doctor, and see if it can then defy gravitation."

Accordingly Cortlandt took careful aim at the object, about twenty-yards away, and fired. The main portion of the jellyfish, with the snake still in its embrace, sailed away, but many pounds of jelly fell to the ground. Most of this remained where it had fallen, but a few of the larger pieces showed a faint luminosity and rose again.

"You cannot kill that which is simply a mass of protoplasm," said Cortlandt. "Doubtless each of those pieces will form a new organism. This proves that there are ramifications and developments of life which we never dreamed of."

2.7. AN UNSEEN HUNTER.

They calculated that they had come ten or twelve miles from the place at which they built the raft, while the damp salt breeze blowing from the south showed them they were near the ocean. Concluding that large bodies of water must be very much alike on all planets, they decided to make for a range of hills due north and a few miles off, and to complete the circuit of the square in returning to the Callisto. The soft wet sand was covered with huge and curious tracks, doubtless made by creatures that had come to the stream during the night to drink, and they noticed with satisfaction as they set out that the fresher ones led off in the direction in which they were going. For practice, they blew off the heads of the boa-constrictors as they hung from the trees, and of the other huge snakes that moved along the

ground, with explosive bullets, in every thicket through which they passed, knowing that the game, never having been shot at, would not take fright at the noise. Sometimes they came upon great masses of snakes, intertwined and coiled like worms; in these cases Cortlandt brought his gun into play, raking them with duck-shot to his heart's content. "As the function of these reptiles," he explained, "is to form a soil on which higher life may grow, we may as well help along their metamorphosis by artificial means." They were impressed by the tremendous cannon-like reports of their firearms, which they perceived at once resulted from the great density of the Jovian atmosphere. And this was also a considerable aid to them in making muscular exertion, for it had just the reverse effect of rarefied mountain air, and they seldom had to expand their lungs fully in order to breathe.

The ground continued to be marked with very large footprints. Often the impressions were those of a biped like some huge bird, except that occasionally the creature had put down one or both forefeet, and a thick tail had evidently dragged nearly all the time it walked erect. Presently, coming to

something they had taken for a large flat rock, they were surprised to see it move. It was about twelve feet wide by eighteen feet long, while its shell seemed at least a foot thick, and it was of course the largest turtle they had ever seen.

"Twenty-four people could dine at a table of this size with ease," said Bearwarden, "while it would make soup for a regiment. I wonder if it belongs to the snapping or diamond-backed species."

At this juncture the monster again moved.

"As it is heading in our direction," resumed Bearwarden, "I vote we strike for a free pass," and, taking a run, he sprang with his spiked boots upon the turtle's shell and clambered upon the flat top, which was about six feet from the ground. He was quickly followed by Ayrault, who was not much ahead of Cortlandt, for, notwithstanding his fifty years, the professor was very spry. The tortoise was almost the exact counterpart of the Glyptodon asper that formerly existed on earth, and shambled along at a jerky gait, about half as fast again as they could walk, and while it continued to go in their direction they were greatly pleased. They soon found that by dropping the butts of their rifles sharply and simultaneously

on either side, just back of the head, they could direct their course, by making their steed swerve away from the stamping.

"It is strange," said Ayrault, "that, with the exception of the mastodon and this tortoise, we have seen none of the monsters that seem to appear at the close of Carboniferous periods, although the ground is covered with their tracks."

"Probably we did not reach the grounds at the right time of day," replied Bearwarden. "The large game doubtless stays in the woods and jungles till night."

"I fancy," said Cortlandt, "we shall find representatives of all the species that once lived upon the earth. In the case of the singing flowers and the Jack-o'-lantern jelly-fish, we have, in addition, seen developments the existence of which no scientist has ever before even suspected."

Occasionally the tortoise stopped, whereupon they poked it from behind with their knives. It was a vicious-looking brute, and had a huge horny beak, with which it bit off young trees that stood in its way as though they had been blades of grass. They were passing through a valley about half a mile wide,

bordered on each side by woods, when Bearwarden suddenly exclaimed, "Here we have it!" and, looking forward, they unexpectedly saw a head rise and remain poised about fifteen feet from the ground. It was a dinosaur, and belonged to the scaled or armoured species. In a few moments another head appeared, and towered several feet above the first. The head was obviously reptilian, but had a beak similar to that of their tortoise. The hind legs were developed like those of a kangaroo, while the small rudimentary forepaws, which could be used as hands or for going quadruped-fashion, now hung down. The strong thick tail was evidently of great use to them when standing erect, by forming a sort of tripod.

"How I wish we could take a pair of those creatures with us when we return to the earth!" said Cortlandt.

"They would be trump cards," replied Bearwarden, "in a zoological garden or a dime museum, and would take the wind out of the sails of all the other freaks."

As they lay flat on the turtle's back, the monsters gazed at them unconcernedly, munching the palm-

tree fruit so loudly that they could be heard a long distance.

"Having nothing to fear from a tortoise," resumed Cortlandt, "they may allow us to stalk them. We are in their eyes like hippocentaurs, except that we are part of a tortoise instead of part of a horse, or else they take us for a parasite or fibrous growth on the shell."

"They would not have much to fear from us as we really are," replied Bearwarden, "were it not for our explosive bullets."

"I am surprised," said Ayrault, "that graminivorous animals should be so heavily armed as these, since there can be no great struggle in obtaining their food."

"From the looks of their jaws," replied Cortlandt, "I should say they are omnivorous, and would doubtless prefer meat to what they are eating now. Something seems to have gone wrong with the animal creation hereabouts to-day."

Their war-horse clanked along like a badly rusted machine, approaching the dinosaurs obliquely. When only about fifty yards intervened, as the hunters were preparing to aim, their attention was diverted by a

tremendous commotion in the woods on their left and somewhat ahead. With the crunching of dead branches and swaying of the trees, a drove of monsters made a hasty exit and sped across the open valley. Some showed only the tops of their backs above the long grass, while others shambled and leaped with their heads nearly thirty feet above the ground. The dinosaurs instantly dropped on all-fours and joined in the flight, though at about half-minute intervals they rose on their hind legs and for a few seconds ran erect. The drove passed about half a mile before the travellers, and made straight for the woods opposite; but hardly had the monsters been out of sight two minutes when they reappeared, even more precipitately than before, and fled up the valley in the same direction as the tortoise.

"The animals here," said Bearwarden, "behave as though they were going to catch a train; only our friend beneath us seems superior to haste."

"I would give a good deal to know," said Cortlandt, "what is pursuing those giants, and whether it is identical or similar to the mutilator of the mastodon. Nothing but abject terror could make them run like that."

"I have a well-formed idea," said Bearwarden, "that a hunt is going on, with no doubt two parties, one in the woods on either side, and that the hunters may be on a scale commensurate with that of their victims."

"If the excitement is caused by men," replied Cortlandt, "our exploration may turn out to be a far more difficult undertaking than we anticipated. But why, if there are men in those woods, do they not show themselves? — for they could certainly keep pace with the game more easily in the open than among the trees."

"Because," replied Bearwarden, "the men in the woods are doubtless the beaters, whose duty it is to drive the game into and up the valley, at the end of which the killing will be done."

"We may have a chance to see it," said Ayrault, "or to take a hand, for we are travelling straight in that direction, and shall be able to give a good account ourselves if our rights are challenged."

"Why," asked Cortlandt, "if the hunting parties that have been in our vicinity were only beaters, should they have mutilated the mastodon in such it way that he could not walk? And how were they

able to take themselves off so quickly — for man in his natural state has never been a fast mover? I repeat, it will upset my theories if we find men."

It was obvious to them that tortoises were not much troubled by the apparently general foe, for the specimen in which they were just then interested continued his course entirely unconcerned. Soon, however, he seemed to feel fatigue, for he drew his feet and head within his shell, which he tightly closed, and after that no poking or prodding had the desired effect.

"I suspect we must depend on shank's mares for a time," said Bearwarden, cheerfully, as they scrambled down.

"We can now see," said Cortlandt, "why our friend was so unconcerned, since he has but to draw himself within himself to become invulnerable to anything short of a stroke of lightning; for no bird could have power enough to raise and drop him from a great height upon rocks, as the eagles do on earth."

"I suspect, if anxious for turtle soup," said Bearwarden, "we must attach a lightning — rod, and wait for a thunderstorm to electrocute him."

2.8. SPORTSMEN'S REVERIES.

Feeling grateful to the huge tortoise for the good service he had rendered, they shot a number of the great snakes that were gliding about on the ground, and placed them where he would find them on awaiting. They then picked their way carefully towards stretches on which the grass was shortest. When they had gone about two miles, and had already reached higher ground, they came to a ridge of rock running at right angles to their course. This they climbed, and on looking over the edge of the crest beheld a sight that made their hearts stand still. A monster, somewhat resembling an alligator, except that the back was arched, was waddling about perhaps seventy-five yards from them. It was sixty feet long, and to the top of its scales was at least twenty-five feet high. It was constantly moving, and

the travellers noticed with some dismay that its motion was far more rapid than they would have supposed it could be.

"It is also a dinosaur," said the professor, watching it sharply, "and very closely resembles the Stegosaurus ungulatus restored in the museums. The question is, What shall we do with the living specimen, now that we have it?"

"Our chairman," said Ayrault, "must find a way to kill it, so that we may examine it closely."

"The trouble is," said Bearwarden, "our bullets will explode before they penetrate the scales. In the absence of any way of making a passage for an explosive ball by means of a solid one, we must strike a vital spot. His scales being no harder than the trunk of a tree, we can wound him terribly by touching him anywhere; but there is no object in doing this unless we can kill him, especially as there is no deep stream, such as would have delayed the mastodon in reaching us, to protect us here. We must spread out so as to divert his attention from one to another."

After some consultation it was decided that Cortlandt, who had only a shot-gun, should remain where

they were, while Bearwarden and Ayrault moved some distance to the right and left. At a signal from Cortlandt, who was to attract the monster's attention, the wings were to advance simultaneously. These arrangements they carried out to the letter. When Bearwarden and Ayrault had gone about twenty-five yards on either side, the doctor imitated the peculiar grunting sound of an alligator, at which the colossal monster turned and faced him, while Bearwarden and Ayrault moved to the attack. The plan of this was good, for, with his attention fixed on three objects, the dinosaur seemed confused, and though Bearwarden and Ayrault had good angles from which to shoot, there was no possibility of their hitting each other. They therefore advanced steadily with their rifles half up. Though their own danger increased with each step, in the event of their missing, the chance of their shooting wild decreased, the idea being to reach the brain through the eye. Cortlandt's part had also its risks, for, being entirely defenceless with his shot-gun against the large creature, whose attention it was his duty to attract, he staked all on the marksmanship of his friends. Not considering this, however, he stood his ground, having the thumb-piece on his Winchester magazine shoved up and ready to make a noisy diversion if necessary in behalf of either wing. Having aroused the monster's curiosity, Cortlandt sprang up, waving his arms and his gun. The dinosaur lowered his head as if to charge, thereby bringing it to a level with the rifles, either of which could have given it the fatal shot. But as their fingers pressed the triggers the reptile soared up thirty feet in the air. Ayrault pulled for his first sight, shooting through the lower jaw, and shivering that member, while Bearwarden changed his aim and sighted straight for the heart. In an instant the monster was down again, just missing Ayrault's head as he stepped back, and Bearwarden's rifle poured a stream of explosive balls against its side, rending and blowing away the heavy scales. Having drawn the dinosaur's attention to himself, he retreated, while Ayrault renewed the attack. Cortlandt, seeing that the original plan had miscarried, poured showers of small shot against the huge beast's face. Finally, one of Ayrault's balls exploded in the brain, and all was over.

"We have killed it at last," said Bearwarden but the first attack, though artistic, had not the

brilliant results we expected. These creatures' mode of fighting is doubtless somewhat similar to that of the kangaroo, which it is said puts its forepaws gently, almost lovingly, on a man's shoulders, and then disembowels him by the rapid movement of a hind leg. But we shall get used to their method, and can do better next time."

They then reloaded their weapons and, while Cortlandt examined their victim from a naturalist's point of view, Bearwarden and Ayrault secured the heart, which they thought would be the most edible part, the operation being rendered possible by the amount of armour the explosive balls had stripped off.

"To-morrow," said Bearwarden, "we must make it a point to get some well-fed birds; for I can roast, broil, or fricassee them to a turn. Life is too short to live on this meat in such a sportsman's paradise. In any case there can be no end of mastodons, mammoths, woolly rhinoceroses, moa birds, and all such shooting."

As the sun was already near the horizon, they chose a dry, sandy place, to secure as much immunity as possible from nocturnal visits, and, after pro

curing a supply of water from a pool, proceeded to arrange their camp for the night. They first laid out the protection-wires, setting them while the sun still shone. Next they built a fire and prepared their evening meal. While they ate it, twilight became night, and the fire-flies, twinkling in legions in the neighbouring valley, seemed like the lamps of a great city.

"Their lights," said Bearwarden, pointing to them, are not as fine as the jelly-fish Will-o'-the wisps were last night, but they are not so dangerous. No gymnotus or electric eel that I have ever seen compared with them, and I am convinced that any one of us they might have touched would have been in kingdom come."

The balmy air soothed the travellers' brows as they reclined against mounds of sand, while the flowers in the valley sent up their dying notes. One by one the moons arose, till four — among them the Lilliputian, discovered by Prof. Barnard in 1893 — were in the sky, flooding the landscape with their silvery light, and something in the surroundings touched a sympathetic cord in the men.

"Oh that I were young again," said Cortlandt,

"and had life before me! I should like to remain here and grow up with this planet, in which we already perceive the next New World. The beauties of earth are barren compared with the scenes we have here."

You remember," replied Bearwarden, "how Cicero defends old age in his De Senectute, and shows that while it has almost everything that youth has, it has also a sense of calm and many things besides."

"Yes," answered Cortlandt, "but, while plausible, it does not convince. The pleasures of age are largely negative, the old being happy when free from pain."

"Since the highest joy of life," said Ayrault, "is coming to know our Creator, I should say the old, being further advanced, would be the happier of the two. I should never regard this material life as greatly to be prized for itself. You remember the old song:

"`O Youth! When we come to consider

The pain, the toil, and the strife,

The happiest man of all is

The one who has finished his life.'

"I suspect," continued Ayrault, "that the man who reaches even the lowest plane in paradise will find far more beautiful visions than any we have here."

As they had but little rest the night before, they were all tired. The warm breeze swayed the long dry grass, causing it to give out a soft rustle; all birds except the flitting bats were asleep among the tall ferns or on the great trees that spread their branches towards heaven. There was nothing to recall a picture of the huge monsters they had seen that day, or of the still more to be dreaded terror these had borne witness to. Thus night closes the activities of the day, and in its serene grandeur the soul has time to think. While they thought, however, drowsiness overcame them, and in a little while all were asleep.

The double line of protection-wires encircled them like a silent guard, while the methodical ticking of the alarm-clock that was to wake them at the approach of danger, and register the hour of interruption, formed a curious contrast to the irregular cries of the night-hawks in the distance. Time and again some huge iguanodon or a hipsohopus would

pass, shaking the ground with its tread; but so implicit was the travellers' trust in the vigilance of their mechanical and tireless watch, that they slept on as calmly and unconcernedly as though they had been in their beds at home, while the tick was as constant and regular as a sentry's march. The wires of course did not protect them from creatures having wings, and they ran some risk of a visitation from the blood-sucking bats. The far-away volcanoes occasionally sent up sheets of flame, which in the distance were like summer lightning; the torrents of lava and crashes that had sounded so thunderous when near, were now like the murmur of the ocean's ebb tide, lulling the terrestrials to deeper sleep. The pale moons were at intervals momentarily obscured by the rushing clouds in the upper air, only to reappear soon afterwards as serene as before. All Nature seemed at rest.

Shortly before dawn there was an unusually heavy step. A moment later the ever-vigilant batteries poured forth their current, and the clang of the alarm-bell made the still night ring. In an instant the three men were awake, each resting on one knee, with their backs towards the centre and

their polished barrels raised. It was not long before they perceived the intruder by the moonlight. A huge monster of the Triceratops prorsus species had entered the camp. It was shaped something like an elephant, but had ten or twelve times the bulk, being over forty feet in length, not including the long, thick tail. The head carried two huge horns on the forehead and one on the nose.

"A plague on my shot-gun!" said Cortlandt. "Had I known how much of this kind of game we should see, I too should have brought a rifle."

The monster was entangled in the wires, and in another second would have stepped on the batteries that were still causing the bell to ring.

"Aim for the heart," said Bearwarden to Ayrault. "When you show me his ribs, I will follow you in the hole."

Ayrault instantly fired for a point just back of the left foreleg. The explosion had the same effect as on the mastodon, removing a half-barrel of hide, etc; and the next second Bearwarden sent a bullet less than an inch from where Ayrault's had stopped. Before the colossus could turn, each had caused several explosions in close proximity to the

first. The creature was of course terribly wounded, and several ribs were cracked, but no ball had gone through. With a roar it made straight for the woods, and with surprising agility, running fully as fast as an elephant. Bearwarden and Ayrault kept up a rapid fire at the left hind leg, and soon completely disabled it. The dinosaur, however, supported itself with its huge tail, and continued to make good time. Knowing they could not give it a fatal wound at the intervening distance, in the uncertain light, they stopped firing and set out in pursuit. Cortlandt paused to stop the bell that still rang, and then put his best foot foremost in regaining his friends. For half a mile they hurried along, until, seeing by the quantity of blood on the ground that they were in no danger of losing the game, they determined to save their strength. The trail entered the woods by a narrow ravine, passed through what proved to be but a belt of timber, and then turned north to the right. Presently in the semi-darkness they saw the monster's head against the sky. He was browsing among the trees, tearing off the young branches, and the hunters succeeded in getting within seventy-five yards before being discovered. Just as he began to run, the two rifles again fired, this time at the right hind leg, which they succeeded in hamstringing. After that the Triceratops prorsus was at their mercy, and they quickly put an end to its suffering.

"The sun is about to rise," said Bearwarden; in a few minutes we shall have enough light."

They cut out a dozen thick slices of tenderloin steak, and soon were broiling and eating a substantial breakfast.

"There are not as many spectators to watch us eat here," said Cortlandt, "as in the woods. I suggest that, after returning to camp for our blankets and things, we steer for the Callisto, via this Triceratops, to see what creatures have been attracted by the body."

On finishing their meal they returned to the place at which they had passed the night. Having straightened the protection-wires, which had become twisted, and arranged their impedimenta, they set out, and were soon once more beside their latest victim.

2.9. THE HONEY OF DEATH.

At first nothing seemed to have been disturbed, when they suddenly perceived that both forelegs were missing. On further examination they found that the ponderous tail, seven feet in diameter, was cut through in two places, the thicker portion having disappeared, and that the heavy bones in this extremity of the vertebral column had been severed like straws. The cut surfaces were but little cooler than the interior of the body, showing how recently the mutilation had been effected.

"By all the gods!" exclaimed Bearwarden, "it is easy to see the method in this; the hunters have again cut off only those parts that could be easily rolled. These Jovian fellows must have weapons compared with which the old scythe chariots would be but toys, with which they amputate the legs of

their victims. We must see to it that their scimitars do not come too near to us, and I venture to hope that in our bullets they will find their match. What say you, doctor?"

"I see no depression such as such heavy bodies would necessarily have made had they been rolled along the ground, neither does it seem to me that these curious tracks in the sand are those of men."

The loose earth looked as if the cross-ties of some railroad had been removed, the space formerly occupied having been but partly filled, and these depressions were across the probable direction of motion.

"Whatever was capable of chasing mastodons and carrying such weights," said Ayrault, "will, I suspect, have little to fear from us. Probably nothing short of light artillery would leave much effect."

"I dare say," replied Bearwarden, "we had better give the unknown quantity a wide berth, though I would give a year's salary to see what it is like. The absence of other tracks shows that his confreres leave `Scissor-jaw' alone."

Keeping a sharp lookout in all directions, they

resumed their march along the third side of the square which was to bring them back to the Callisto. Their course was parallel to the stream, and on comparatively high ground. Cortlandt's gun did good service, bringing down between fifty and sixty birds that usually allowed them to get as near as they pleased, and often seemed unwilling to leave their branches. By the time they were ready for luncheon they saw it would be dark in an hour. As the rapidity of the planet's rotation did not give them a chance to become tired, they concluded not to pitch their camp, but to resume the march by moonlight, which would be easy in the high, open country they were traversing.

While in quest of fire-wood, they came upon great heaps of bones, mostly those of birds, and were attracted by the tall, bell-shaped flowers growing luxuriantly in their midst. These exhaled a most delicious perfume, and at the centre of each flower was a viscous liquid, the colour of honey.

"If this tastes as well as it looks," said Bearwarden, "it will come in well for dessert"; saying which he thrust his finger into the recesses of the flower, intending to taste the essence. Quietly, but

like a flash, the flower closed, his hand being nearly caught and badly scratched by the long, sharp thorns that now appeared at the edges.

"Ha!" he exclaimed, "a sensitive and you may almost say a man-eating plant. This doubtless has been the fate of these birds, whose bones now lie bleaching at its feet after they have nourished its lips with their lives. No doubt the plant has use for them still, since their skeletons may serve to fertilize its roots."

Wishing to investigate further, Bearwarden placed one of the birds they had shot within the bell of another flower, which immediately contracted with such force that they saw drops of blood squeezed out. After some minutes the flower opened, as beautiful as ever, and discharged an oblong ball compressed to about the size of a hen's egg, though the bird that was placed within it had been as large as a small duck. Towards evening these flowers sent up their most beautiful song, to hear which flocks of birds came from far and near, alighting on the trees, and many were lured to death by the siren strains and the honey.

Before resuming their journey, the travellers paid

a parting visit to the bell-shaped lilies on their pyramids of bones. The flowers were closed for the night, and the travellers saw by the moonlight that the white mounds were simply alive with diamond-headed snakes. These coiled themselves, flattened their heads, and set up such a hissing on the explorers' approach that they were glad to retire, and leave this curious contrast of hideousness and beauty to the fire-flies and the moons. Marching along in Indian file, the better to avoid treading on the writhing serpents that strewed the ground, they kept on for about two hours. They frequently passed huge heaps or mounds of bones, evidently the remains of bears or other large animals. The carnivorous plants growing at their centre were often like hollow trees, and might easily have received the three travellers in one embrace. But as before, the mounds were alive with serpents that evidently made them their homes, and raised an angry hiss whenever the men approached.

"The wonder to me," said Bearwarden, "is, that these snakes do not protect the game, by keeping it from the life-devouring plants. It may be that they do not show themselves by day or when the victims are near, or that the quadrupeds on which these

plants live take a pleasure, like deer, in killing them by jumping with all four feet upon their backs or in some other way, and after that are entrapped by the flowers."

Shortly after midnight they rested for a half hour, but the dawn found them trudging along steadily, though somewhat wearily, and having about completed the third side of their square. Accordingly, they soon made a right-angle turn to the left, and had been picking their way over the rough ground for nearly two hours, with the sun already high in the sky, when they noticed a diminution of light. Glancing up, they saw that one of the moons was passing across the sun, and that they were on the eve of a total eclipse.

"Since all but the fifth moon," said Cortlandt, "revolve exactly in the plane of Jupiter's equator, any inhabitants that settle there will become accustomed to eclipses, for there must be one of the sun, and also of the moons, at each revolution, or about forty-five hundred in every Jovian year. The reason we have seen none before is, because we are not exactly on the equator."

They had a glimpse of the coronal streamers as the

last portion of the sun was covered, and all the other phenomena that attend an eclipse on earth. For a few minutes there was a total return to night. The twinkling stars and other moons shone tranquilly in the sky, and even the noise of the insects ceased. Presently the edge of the sun that had been first obscured reappeared, and then Nature went through the phenomenon of an accelerated dawn. Without awaiting a full return of light, the travellers proceeded on their way, and had gone something over a hundred yards when Ayrault, who was marching second, suddenly grasped Bearwarden, who was in front, and pointed to a jet-black mass straight ahead, and about thirty yards from a pool of warm water, from which a cloud of vapour arose. The top of the head was about seven feet high, and the length of the body exceeded thirty feet. The six legs looked as strong as steel cables, and were about a foot through, while a huge, bony proboscis nine feet in length preceded the body. This was carried horizontally between two and three feet from the ground. Presently a large ground sloth came to the pool to drink, lapping up the water at the sides that had partly cooled. In an instant the black armored monster rushed down the slope with the speed of a nineteenth-century locomotive, and seemed about as formidable. The sloth turned in the direction of the sound, and for a moment seemed paralyzed with fear; it then started to run, but it was too late, for the next second the enormously exaggerated ant — for such it was — overtook it. The huge mandible shears that when closed had formed the proboscis, snapped viciously, taking off the sloth's legs and then cutting its body to slivers. The execution was finished in a few seconds, and the ponderous insect carried back about half the sloth to its hiding-place, where it leisurely devoured it.

"This reminds me," said Bearwarden, "of the old lady who never completed her preparations for turning in without searching for burglars under the bed. Finally she found one, and exclaimed in delight, `I've been looking for you fifty years, and at last you are here!' The question is, now that we have found our burglar, what shall we do with him?"

"I constantly regret not having a rifle," replied Cortlandt, "though it is doubtful if even that would help us here."

"Let us sit down and wait," said Ayrault; "there may be an opening soon."

Anon a woolly rhinoceros, resembling the Rhinoceros tichorhinus that existed contemporaneously on earth with the mammoth, came to drink the water that had partly cooled. It was itself a formidable-looking beast, but in an instant the monster again rushed from concealment with the same tremendous speed. The rhinoceros turned in the direction of the sound, and, lowering its head, faced the foe. The ant's shears, however, passed beneath the horn, and, fastening upon the left foreleg, cut it off with a loud snap.

"Now is our chance," exclaimed Cortlandt; "we may kill the brute before he is through with the rhinoceros."

"Stop a bit, doctor," said Bearwarden. "We have a good record so far; let us keep up our reputation for being sports. Wait till he can attend to us."

The encounter was over in less than a minute, three of the rhinoceros's legs being taken off, and the head almost severed from the body. Taking up the legs in its mandibles, the murderous creature was returning to its lair, when, with the cry of "Now for

the fray!" Bearwarden aimed beneath the body and blew off one of the farther armoured legs, from the inside. "Shoot off the legs on the same side," he counselled Ayrault, while he himself kept up a rapid fire. Cortlandt tried to disconcert the enemy by raining duck-shot on its scale-protected eyes, while the two rifles tore off great masses of the horn that covered the enormously powerful legs. The men separated as they retreated, knowing that one slash of the great shears would cut their three bodies in halves if they were caught together. The monster had dropped the remains of the rhinoceros when attacked, and made for the hunters at its top speed, which was somewhat reduced by the loss of one leg. Before it came within cutting distance, however, another on the same side was gone, Ayrault having landed a bullet on a spot already stripped of armour. After this the men had no difficulty in keeping out of its way, though it still moved with some speed, snipping off young trees in its path like grass. Finally, having blown the scales from one eye, the travellers sent in a bullet that exploded in the brain and ended its career.

"This has been by all odds the most exciting

hunt we have had," said Ayrault, "both on account of the determined nature and great speed of the attack, and the almost impossibility of finding a vulnerable spot."

"Anything short of explosive bullets," added Bearwarden, "would have been powerless against this beast, for the armour in many places is nearly a foot thick."

"This is also the most extraordinary as well as most dangerous creature with which we have, had to deal," said Cortlandt, because it is an enormously enlarged insect, with all the inherent ferocity and strength. It is almost the exact counterpart of an African soldier-ant magnified many hundred thousand times. I wonder," he continued thoughtfully, "if our latter-day insects may not be the deteriorated (in point of size) descendants of the monsters of mythology and geology, for nothing could be a more terrible or ferocious antagonist than many of our well-known insects, if sufficiently enlarged. No animal now alive has more than a small fraction of the strength, in proportion to its size, of the minutest spider or flea. It may be that through lack of food, difficulties imposed by changing climate, and the necessity

of burrowing in winter, or through some other conditions changed from what they were accustomed to, their size has been reduced, and that the fire-flies, huge as they seemed, are a step in advance of this specimen in the march of deterioration or involution, which will end by making them as insignificant as those on earth. These ants have probably come into the woods to lay their eggs, for, from the behaviour of the animals we watched from the turtle, there must have been several; or perhaps a war is in progress between those of a different colour, as on earth, in which case the woods may be full of them. Doubtless the reason the turtle seemed so unconcerned at the general uneasiness of the animals was because he knew he could make himself invulnerable to the marauder by simply closing his shell, and we were unmolested because it did not occur to the ant that any soft-shelled creatures could be on the turtle's back."

"I think," said Bearwarden, "it will be the part of wisdom to return to the Callisto, and do the rest of our exploring on Jupiter from a safe height; for, though we succeeded in disabling this beauty, it was largely through luck, and had we not done so we

should probably have provided a bon bouche for our deceased friend, instead of standing at his grave."

Accordingly they proceeded, and were delighted, a few minutes later, to see the sunlight reflected from the projectile's polished roof.

2.10. CHANGING LANDSCAPES.

On reaching the Callisto, Ayrault worked the lock he had had placed on the lower door, which, to avoid carrying a key, was opened by a combination. The car's interior was exactly as they had left it, and they were glad to be in it again.

"Now," said Bearwarden, "we can have a sound and undisturbed sleep, which is what I want more than anything else. No prowlers can trouble us here, and we shall not need the protection-wires."

They then opened a window in each side — for the large glass plates, admitting the sun when closed, made the Callisto rather warm — and placed a stout wire netting within them to keep out birds and bats, and then, though it was but little past noon, got into their comfortable beds and slept nine hours at a stretch. Their strong metal house was securely at

rest, receiving the sunlight and shedding the rain and dew as it might have done on earth. No winds or storms, lightnings or floods, could trouble it, while the multiformed monsters of antiquity and mythology restored in life, with which the terrestrials had been thrown into such close contact, roamed about its polished walls. Not even the fiercest could affect them, and they would but see themselves reflected in any vain assaults. The domed symmetrical cylinder stood there as a monument to human ingenuity and skill, and the travellers' last thought as they fell asleep was, "Man is really lord of creation."

The following day at about noon they awoke, and had a bath in the warm pool. They saw the armoured mass of the great ant evidently undisturbed, while the bodies of its victims were already shining skeletons, and raised a small cairn of stones in memory of the struggle they had had there.

"We should name this place Kentucky," said Bearwarden, "for it is indeed a dark and bloody ground," and, seeing the aptness of the appellation, they entered it so on their charts. While Ayrault got the batteries in shape for resuming work. Bearwarden prepared a substantial breakfast. This consisted

of oatmeal and cream kept hermetically sealed in glass, a dish of roast grouse, coffee, pilot bread, a bottle of Sauterne, and another of Rhine wine.

"This is the last meal we shall take hereabouts," said their cook, as they plied their knives and forks beneath the trees, "so here is a toast to our adventures, and to all the game we have killed." They drained their glasses in drinking this, after which Bearwarden regaled them with the latest concert-hall song which he had at his tongue's end.

About an hour before dark they re-entered their projectile, and, as a mark of respect to their little ship, named the great branch of the continent on which they had alighted Callisto Point. They then got under way. The batteries had to develop almost their maximum power to overcome Jupiter's attraction; but they were equal to the task, and the Callisto was soon in the air. Directing their apergy to the mountains towards the interior of the continent, and applying repulsion to any ridge or hill over which they passed, thereby easing the work of the batteries engaged in supporting the Callisto, they were soon sweeping along at seventy-five to one hundred miles

an hour. By keeping the projectile just strongly enough charged to neutralize gravitation, they remained for the most part within two hundred feet of the ground, seldom rising to an altitude of more than a mile, and were therefore able to keep the windows at the sides open and so obtain an unobstructed view. If, however, at any time they felt oppressed by Jupiter's high barometric pressure, and preferred the terrestrial conditions, they had but to rise till the barometer fell to thirty. Then, if an object of interest recalled them to sea-level, they could keep the Callisto's inside pressure at what they found on the Jovian mountains, by screwing up the windows. On account of the distance of sixty-four thousand miles from Jupiter's equator to the pole, they calculated that going at the speed of a hundred miles an hour, night and day, it would take them twenty-five terrestrial days to reach the pole even from latitude two degrees at which they started. But they knew that, if pressed for time, they could rise above the limits of the atmosphere, and move with planetary speed; while, if they wished a still easier method of pursuing their observation, they had but to remain poised between the sun and Jupiter, beyond the latter's upper air, and photograph or map it as it revolved before them.

By sunset they had gone a hundred miles. Wishing to push along, they closed the windows, rose higher to avoid any mountain-tops that might be invisible in the moonlight, and increased their speed. The air made a gentle humming sound as they shot through it, and towards morning they saw several bright points of light in which they recognized, by the aid of their glasses, sheets of flame and torrents of molten glowing lava, bursting at intervals or pouring steadily from several volcanoes. >From this they concluded they were again near an ocean, since volcanoes need the presence of a large body of water to provide steam for their eruptions.

With the rising sun they found the scene of the day before entirely changed. They were over the shore of a vast ocean that extended to the left as far as they could see, for the range of vision often exceeded the power of sight. The coast-line ran almost due north and south, while the volcanoes that dotted it, and that had been luminous during the night, now revealed their nature only by lines of smoke and vapours. They were struck by the boldness and abruptness

of the scenery. The mountains and cliffs had been but little cut down by water and frost action, and seemed in the full vigour of their youth, which was what the travellers had a right to expect on a globe that was still cooling and shrinking, and consequently throwing up ridges in the shape of mountains far more rapidly than a planet as matured and quiescent as the earth. The absence of lakes also showed them that there had been no Glacial period, in the latitudes they were crossing, for a very long time.

We can account for the absence of ice-action and scratches," said Cortlandt, "in one of two ways. Either the proximity of the internal heat to the surface prevents water from freezing in all latitudes, or Jupiter's axis has always been very nearly perpendicular to its orbit, and consequently the thermometer has never been much below thirty-two degrees Fahrenheit; for, at the considerable distance we are now from the sun, it is easy to conceive that, with the axis much inclined, there might be cold weather, during the Northern hemisphere's winter, that would last for about six of our years, even as near the equator as this. The substantiation of an ice-cap at the pole

will disprove the first hypothesis; for what we took for ice before alighting may have been but banks of cloud, since, having been in the plane of the planet's equator at the time, we had naturally but a very oblique view of the poles; while the absence of glacial scratches shows, I take it, that though the axis may have been a good deal more inclined than at present, it has not, at all events since Jupiter's Palaeozoic period, been as much so as that of Uranus or Venus. The land on Jupiter, corresponding to the Laurentian Hills on earth, must even here have appeared at so remote a period that the first surface it showed must long since have been worn away, and therefore any impressions it received have also been erased.

Comparing this land with the photographs we took from space, I should say it is the eastern of the two crescent-shaped continents we found apparently facing each other. Their present form I take to be only the skeleton outline of what they will be at the next period of Jupiter's development. They will, I predict, become more like half moons than crescents, though the profile may be much indented by gulfs and bays, their superficial area being greatly increased, and the intervening ocean correspondingly

narrowed. We know that North America had a very different shape during the Cretaceous or even the Middle Tertiary period from what it has now, and that the Gulf of Mexico extended up the valley of the Mississippi as far as the Ohio, by the presence of a great coral reef in the Ohio River near Cincinnati. We know also that Florida and the Southeastern Atlantic States are a very recent addition to the continent, while the pampas of the Argentine Republic have, in a geological sense, but just been upheaved from the sea, by the fact that the rivers are all on the surface, not having had time to cut down their channels below the surrounding country. By similar reasoning, we know that the canon of the Colorado is a very old region, though the precipitateness of its banks is due to the absence of rain, for a local water-supply would cut back the banks, having most effect where they were steepest, since at those points it would move with the greatest speed. Thus the majestic canon owes its existence to two things: the length of time the river has been at work, and the fact that the water flowing through it comes from another region where, of course, there is rain, and that it is merely in transit, and so affects only the bed on which it moves. Granting that this is the eastern of the two continents we observed, it evidently corresponds more in shape to the Eastern hemisphere on earth than to the New World, both of which are set facing one another, since both drain towards the Atlantic Ocean. But the analogy here holds also, for the past outlines of the Eastern hemisphere differed radically from what they are now. The Mediterranean Sea was formerly of far greater extent than we see it to-day, and covered nearly the whole of northern Africa and the old upheaved sea-bottom that we see in the Desert of Sahara. Much of this great desert, as we know, has a considerable elevation, though part of it is still below the level of the Mediterranean.

"Perhaps a more striking proof of this than are the remains of fishes and marine life that are found there, is the dearth of natural harbours and indentations in Africa's northern coast, while just opposite, in southern Europe, there are any number; which shows that not enough time has elapsed since Africa's upheaval for liquid or congealed water to produce them. Many of Europe's best harbours, and Boston's, in our country, have been dug out by slow

ice-action in the oft-recurring Glacial periods. The Black and Caspian Seas were larger than we now find them; while the Adriatic extended much farther into the continent, covering most of the country now in the valley of the Po. In Europe the land has, of course, risen also, but so slowly that the rivers have been able to keep their channels cut down; proof of their ability to perform which feat we see when an ancient river passes through a ridge of hills or mountains. The river had doubtless been there long before the mountains began to rise, but their elevation was so gradual that the rate of the river's cutting down equalled or exceeded their coming up; proof of which we have in the patent fact that the ancient river's course remains unchanged, and is at right angles to the mountain chain. From all of which we see that the Eastern hemisphere's crescent hollow — of which, I take it, the Mediterranean, Black, and Caspian Sea depressions are the remains — has been gradually filled in, by the elevation of the sea's bottom, and the extension of deltas from the detrital matter brought from the high interior of the continents by the rivers, or by the combined action of the two. Now, since the Gulf of Mexico has been constantly growing smaller, and the Mediterranean is being invaded by the land, I reason that similar causes will produce like effects here, and give to each continent an area far greater than our entire globe. The stormy ocean we behold in the west, which corresponds to our Atlantic, though it is far more of a mare clausum in the geographical sense, is also destined to become a calm and placid inland sea. There are, of course, modifications of and checks to the laws tending to increase the land area. England was formerly joined to the continent, the land connecting the two having been rather washed away by the waves and great tides than by any sinking of the English Channel's bottom, the whole of which is comparatively shallow. Another case of this kind is seen in Cape Cod and the islands of Martha's Vineyard and Nantucket, all of which are washing away so rapidly that they would probably disappear before the next Glacial period, were we not engaged in preventing its recurrence. These detached islands and sand-bars once formed one large island, which at a still earlier time undoubtedly was joined to the mainland. The sands forming the detached masses are in a great processional march towards the equator, but it is the result simply of winds and waves, there being no indication of subsidence. Along the coast of New Jersey we see denudation and sinking going on together, the well-known sunken forest being an instance of the latter. The border of the continent proper also extends many miles under the ocean before reaching the edge of the Atlantic basin. Volcanic eruptions sometimes demolish parts of headlands and islands, though these recompense us in the amount of material brought to the surface, and in the increased distance they enable water to penetrate by relieving the interior of part of its heat, for any land they may destroy."

2.11. A JOVIAN NIAGARA.

Four days later, after crossing a ridge of mountains that the pressure on the aneroid barometer showed to be about thirty-two thousand feet high, and a stretch of flat country a few miles in width, they came to a great arm of the sea. It was about thirty miles wide at its mouth, which was narrowed like the neck of a bottle, and farther inland was over one hundred miles across, and though their glasses, the clear air, and the planet's size enabled them to see nearly five hundred miles, they could not find its end. In the shallow water along its shores, and on the islands rising but a few feet above the waves, they saw all kinds of amphibians and sea-monsters. Many of these were almost the exact reproduction in life of the giant plesiosaurs, dinosaurs, and elasmosaurs, whose remains are preserved in the museums

on earth. The reptilian bodies of the elasmosaurs, seventy-five feet in length, with the forked tongues, distended jaws and fangs of a snake, were easily taken for the often described but probably mythical sea-serpent, as partially coiled they occasionally raised their heads twelve or fifteen feet.

"Man in his natural state," said Cortlandt, would have but small chance of surviving long among such neighbours. Buckland, I think, once indulged in the jeu d'esprit of supposing an ichthyosaur lecturing on the human skull. `You will at once perceive,' said the lecturer, `that the skull before us belonged to one of the lower order of animals. The teeth are very insignificant, the power of the jaws trifling, and altogether it seems wonderful how the creature could have procured food.' Armed with modern weapons, and in this machine, we are, of course, superior to the most powerful monster; but it is not likely that, had man been so surrounded during the whole of his evolution, he could have reached his present plane."

Notwithstanding the striking similarity of these creatures to their terrestrial counterparts that existed on earth during its corresponding period, there

were some interesting modifications. The organs of locomotion in the amphibians were more developed, while the eyes of all were larger, the former being of course necessitated by the power of gravity, and the latter by the greater distance from the sun.

"The adaptability and economy of Nature," said Cortlandt, "have always amazed me. In the total blackness of the Kentucky Mammoth Cave, where eyes would be of no use to the fishes, our common mother has given them none; while if there is any light, though not as much as we are accustomed to, she may be depended upon to rise to the occasion by increasing the size of the pupil and the power of the eye. In the development of the ambulatory muscles we again see her handiwork, probably brought about through the `survival of the fittest.' The fishes and those wholly immersed need no increase in power, for, though they weigh more than they would on earth, the weight of the water they displace is increased at the same rate also, and their buoyancy remains unchanged. If the development of life here so closely follows its lines on earth, with the exception of comparatively slight modifications, which are exactly what, had we stopped to think,

we should have expected to find, may we not reasonably ask whether she will not continue on these lines, and in time produce beings like ourselves, but with more powerful muscles and eyes capable of seeing clearly with less light? Reasoning by analogy, we can come to no other conclusion, unless their advent is anticipated by the arrival of ready-made colonists from the more advanced earth, like ourselves. In that case man, by pursuing the same destructive methods that he has pursued in regard to many other species, may exterminate the intervening links, and so arrest evolution."

Before leaving Deepwaters Bay they secured a pail of its water, which they found, on examination, contained a far larger percentage of salt and solid material than the oceans on earth, while a thermometer that they immediately immersed in it soon registered eighty-five degrees Fahrenheit; both of which discoveries confirmed them in what they already knew, namely, that Jupiter had advanced comparatively little from the condition in which the water on the surface is hot, in which state the earth once was.

They were soon beyond the estuary at which

they had stopped to study the forms of life and to make this test, and kept on due north for several days, occasionally rising above the air. As their familiarity with their surroundings increased, they made notes of several things. The mountains covered far more territory at their bases than the terrestrial mountains, and they were in places very rugged and showed vast yawning chasms. They were also wooded farther up their sides, and bore but little snow; but so far the travellers had not found them much higher than those on earth, the greatest altitude being the thirty-two thousand feet south of Deepwaters Bay, and one other ridge that was forty thousand; so that, compared with the size of the planet and its continents, they seemed quite small, and the continents themselves were comparatively level. They also noted that spray was blown in vast sheets, till the ocean for miles was white as milk. The wind often attained tornado strength, and the whole surface of the water, about what seemed to be the storm centre, frequently moved with rapidity in the form of foam. Yet, notwithstanding this, the waves were never as large as those to which they were accustomed on earth. This they accounted for very easily by the fact that, while water weighed 2.55 times as much as on earth, the pressure of air was but little more than half as much again, and consequently its effect on all but the very surface of the heavy liquid was comparatively slight.

"Gravity is a useful factor here," observed Cortlandt, as they made a note of this; "for, in addition to giving immunity from waves, it is most effective in checking the elevation of high mountains or table-lands in the high latitudes, which we shall doubtless find sufficiently cool, or even cold, while in tropical regions, which might otherwise be too hot, it interferes with them least, on account of being partly neutralized by the rapid rotation with which all four of the major planets are blessed."

At sunrise the following morning they saw they were approaching another great arm of the sea. It was over a thousand miles wide at its mouth, and, had not the photographs showed the contrary, they would have thought the Callisto had reached the northern end of the continent. It extended into the land fifteen thousand miles, and, on account of the shape of its mouth, they called it Funnel Bay. Rising to a height, they flew across, and came to a great

table-land peninsula, with a chain of mountains on either side. The southern range was something over, and the northern something less than, five thousand feet in height, while the table-land between sloped almost imperceptibly towards the middle, in which, as they expected, they found a river compared to which the Mississippi or the Amazon would be but a brook. In honour of the President of the Terrestrial Axis Straightening Company, they called this great projection, which averaged about four thousand miles across by twelve thousand miles long, Bearwarden Peninsula. They already noticed a change in climate; the ferns and palms became fewer, and were succeeded by pines, while the air was also a good deal cooler, which was easily accounted for by their altitude — though even at that height it was considerably denser than at sea-level on earth — and by the fact that they were already near latitude thirty.

The exposed points on the plateau, as also the summits of the first mountains they had seen before alighting, were devoid of vegetation, scarcely so much as a blade of grass being visible. Since they could not account for this by cold, they concluded that the most probable explanation lay in the tremendous hurricanes

that, produced by the planet's rapid rotation, frequently swept along its surface, like the earth's trade-winds, but with far more violence.

On reaching the northern coast of the peninsula they increased their elevation and changed their course to northeast, not caring to remain long over the great body of water, which they named Cortlandt Bay. The thousands of miles of foam fast flew beneath them, the first thing attracting their attention being a change in the ocean's colour. In the eastern shore of Cortlandt Bay they soon observed the mouth of a river, ten miles across, from which this tinted water issued in a flood. On account of its colour, which reminded them of a stream they knew so well, they christened it the Harlem.

Believing that an expedition up its valley might reveal something of interest, they began the ascent, remaining at an elevation of a few hundred feet. For about three hundred miles they followed this river, which had but few bends, while its sides became more and more precipitous, till it flowed through a canon four and a half miles across. Though they knew from the wide discoloration of Cortlandt Bay that the volume of water discharged was tremendous,

the stream seldom moved at a rate of more than five miles an hour, and for a time was free from rocks and rapids, from which they concluded that it must be very deep. Half an hour later they saw a cloud of steam or mist, which expanded, and almost obscured the sky as they approached. Next they heard a sound like distant thunder, which they took for the prolonged eruption of some giant crater, though they had not expected to find one so far towards the interior of the continent. Presently it became one continuous roar, the echo in the canon, whose walls were at this place over six hundred feet high, being simply deafening, so that the near discharge of the heaviest artillery would have been completely drowned.

"One would think the end of the world was approaching!" shouted Cortlandt through his hands.

"Look!" Bearwarden roared back, "the wind is scattering the mist."

As he spoke, the vapoury curtain was drawn aside, revealing a waterfall of such vast proportions as to dwarf completely anything they had ever seen or even imagined. A somewhat open horseshoe lip, three and a half miles straight across and over four miles following the line of the curve, discharged a

sheet of water forty feet thick at the edge into an abyss six hundred feet below. Two islands on the brink divided this sheet of liquid into three nearly equal parts, while myriads of rainbows hovered in the clouds of spray. Two things especially struck the observers: the water made but little curve or sweep on passing over the edge, and then rushed down to the abyss at almost lightning speed, shivering itself to infinitesimal particles on striking any rock or projection at the side. Its behaviour was, of course, due to its weight, and to the fact that on Jupiter bodies fall 40.98 feet the first second, instead of sixteen feet, as on earth, and at correspondingly increasing speed.

Finding that they were being rapidly dazed and stunned by the noise, the travellers caused the Callisto to rise rapidly, and were soon surveying the superb sight from a considerable elevation. Their minds could grasp but slowly the full meaning and titanic power of what they saw, and not even the vast falls in their nearness could make their significance clear. Here was a sheet of water three and a half miles wide, averaging forty feet in depth, moving at a rapid rate towards a sheer fall of six hundred feet. They felt, as they gazed at it, that the power of that

waterfall would turn backward every engine and dynamo on the earth, and it seemed as if it might almost put out the fires of the sun. Yet it was but an illustration of the action of the solar orb exerted on a vast area of ocean, the vapour in the form of rain being afterwards turned into these comparatively narrow limits by the topography of the continent. Compared with this, Niagara, with its descent of less than two hundred feet, and its relatively small flow of water, would be but a rivulet, or at best a rapid stream.

Reluctantly leaving the fascinating spectacle, they pursued their exploration along the river above the falls. For the first few miles the surface of the water was near that of the land; there were occasional rapids, but few rocks, and the foaming torrent moved at great speed, the red sandstone banks of the river being as polished as though they had been waxed. After a while the obstructions disappeared, but the water continued to rush and surge along at a speed of ten or twelve miles an hour, so that it would be easily navigable only for logs or objects moving in one direction. The surface of the river was soon on an average fifty feet below the edge of the banks,

this depression being one result of the water's rapid motion and weight, which facilitated the carving of its channel.

When they had followed up the river about sixty miles towards its source they came upon what at first had the appearance of an ocean. They knew, however, from its elevation, and the flood coming from it, that the water must be fresh, as they soon found it was. This lake was about three hundred miles wide, and stretched from northeast to southwest. There was rolling land with hills about its shores, and the foliage on the banks was a beautiful shade of bluish purple instead of the terrestrial ubiquitous green.

When near the great lake's upper end, they passed the mouth of a river on their left side, which, from its volume, they concluded must be the principal source, and therefore they determined to trace it. They found it to be a most beautiful stream, averaging two and a half miles in width, evidently very deep, and with a full, steady current. After proceeding for several hours, they found that the general placidity grew less, the smooth surface occasionally became ruffled by projecting rocks and rapids, and

the banks rose till the voyagers again found themselves in a ravine or canon.

During their sojourn on Jupiter they had had but little experience with the tremendous winds that they knew, from reason and observation, must rage in its atmosphere. They now heard them whistling over their heads, and, notwithstanding the protection afforded by the sides of the canon, occasionally received a gust that made the Callisto swerve. They kept on steadily, however, till sunset, at which time it became very dark on account of the high banks, which rose as steeply as the Palisades on the Hudson to a height of nearly a thousand feet. Finding a small island near the eastern bank, they were glad to secure the Callisto there for the night, below the reach of the winds, which they, still heard singing loudly but with a musical note in what seemed to them like the sky.

"It is incomprehensible to me." said Ayrault, as they sat at dinner, "how the sun, at a distance of four hundred and eighty-three million miles, can raise the amount of water we have here passing us, and compared with which the discharge of the greatest river on earth would be insignificant, to say nothing

of the stream we ascended before reaching this."

"We must remember," replied Cortlandt, "that many of the conditions are different here from those that exist on earth. We know that some of the streams are warm, and even hot, and that the temperature of Deepwaters Bay, and doubtless that of the ocean also, is considerably higher than ours. This would facilitate evaporation. The density of the atmosphere and the tremendous winds, of which I suspect we may see more later, must also help the sun very much in its work of raising vapour. But the most potent factor is undoubtedly the vast size of the basin that these rivers drain."

"The great speed at which the atmospheric currents move," said Bearwarden, "coupled with the comparative lowness of the mountain chains and the slight obstruction they offer to their passage, must distribute the rain very thoroughly, notwithstanding the great unbroken area of the continents. There can be no such state of things here as exists in the western part of South America, where the Andes are so high that any east-bound clouds, in crossing them, are shoved up so far into a cold region that all

moisture they may have brought from the Pacific is condensed into rain, with which parts of the western slope are deluged, while clouds from the Atlantic have come so far they have already dispersed their moisture, in consequence of which the region just east of the Andes gets little if any rain. It is bad for a continent to have its high mountains near the ocean from which it should get its rain, and good for it to have them set well back."

"I should not be surprised," said Cortlandt, "if we saw another waterfall to-morrow, though not in the shape of rain. In the hour before we stopped we began to see rapids and protruding rocks. That means that we are coming to a part of the channel that is comparatively new, since the older parts have had time to wear smooth. I take it, then, that we are near the foot of a retreating cascade, which we may hope soon to see. That is exactly the order in which we found smooth water and rapids in river No. 1, which we have named the Harlem."

After this, not being tired, they used the remaining dark hours for recording their recent adventures.

2.12. HILLS AND VALLEYS.

With the first light they resumed their journey, and an hour after setting out they sighted, as Cortlandt had predicted, another cloud of vapour. The fall — for such it proved to be — was more beautiful than the other, for, though the volume of water was not so great, it fell at one leap, without a break, and at the same tremendous speed, a distance of more than a thousand feet. The canon rang with the echoes, while the spray flew in sheets against the smooth, glistening, sandstone walls. Instead of coming from a river, as the first fall had, this poured at once from the rocky lip, about two miles across, of a lake that was eleven hundred feet above the surging mass in the vale below.

"It is a thousand pities," said Bearwarden, that this cataract has got so near its source; for, at

the rate these streams must cut, this one in a few hundred years, unless something is done to prevent it, will have worn back to the lake, and then good-bye to the falls, which will become a series of rapids. Perhaps the first effect will be merely to reduce by a few feet the height of the falls, in which case they will remain in practically the same place."

About the shores of this lake they saw rhinoceroses with long thick wool, and herds of creatures that much resembled buffaloes.

"I do not see," said Bearwarden, "why the identical species should not exist here that till recently, in a geological sense, inhabited the earth. The climate and all other conditions are practically the same on both planets, except a trifling difference in weight, to which terrestrials would soon adapt themselves. We know by spectroscopic analysis that hydrogen, iron, magnesium, and all our best-known substances exist in the sun, and even the stars, while the earth contains everything we have found in meteorites. Then why make an exception of life, instead of supposing that at corresponding periods of development the same living forms inhabit all? It would be assuming the eternal sterilization of the

functions of Nature to suppose that our earth is the only body that can produce them."

"The world of organic life is so much more complex," replied Cortlandt, "than that of the crystal, that it requires great continuity. So far we certainly have seen no men, or anything like them, not even so much as a monkey, though I suppose, according to your reasoning, Jupiter has not advanced far enough to produce even that."

"Exactly," replied Bearwarden, "for it will require vast periods; and, according to my belief, at least half the earth's time of habitability had passed before man appeared. But we see Jupiter is admirably suited for those who have been developed somewhere else, and it would be an awful shame if we allowed it to lie unimproved till it produces appreciative inhabitants of its own, for we find more to admire in one half-hour than its entire present population during its lifetime. Yet, how magnificent this world is, and how superior in its natural state to ours! The mountainous horns of these crescent-shaped continents protect them and the ocean they enclose from the cold polar marine currents, and in a measure from the icy winds; while the elevated

country on the horns near the equator might be a Garden of Eden, or ideal resort. To be sure, the continents might support a larger population, if more broken up, notwithstanding the advantage resulting from the comparatively low mountains along the coasts, and the useful winds. A greater subdivision of land and water, more great islands connected by isthmuses, and more mediterraneans joined by straits, would be a further advantage to commerce; but with the sources of power at hand, the resistless winds and water-power, much increased in effectiveness by their weight, the great tides when several moons are on the same side, or opposite the sun, internal heat near the surface, and abundant coal-supply doubtless already formed and also near the surface, such small alterations could be made very easily, and would serve merely to prevent our becoming rusty.

"As Jupiter's distance from the sun varies from 506,563,000 miles at aphelion to only 460,013,000 at perihelion, this difference, in connection with even the slight inclination of the axis, must make a slight change in seasons, but as the inclination is practically nothing, almost the entire change results from the difference in distance. This means that the

rise or fall in temperature is general on every degree of latitude, all being warmed simultaneously, more or less, as the planet approaches or departs from the sun. It means also that about the same conditions that Secretary Deepwaters suggested as desirable for the earth, prevail here, and that Jupiter represents, therefore, about the acme of climate naturally provided. On account of its rapid rotation and vast size, the winds have a tornado's strength, but they are nothing at this distance from the sun to what they would be if a planet with its present rate of rotation and size were where Venus or even the earth is. In either of these positions no land life with which we are acquainted could live on the surface; for the slope of the atmospheric isobars — i. e., the lines of equal barometric pressure that produce wind by becoming tilted through unequal expansion, after which the air, as it were, flows down-hill — would be too great. The ascending currents about the equator would also, of course, be vastly strengthened; so that we see a wise dispensation of Providence in placing the large planets, which also rotate so rapidly, at a great distance from the sun, which is the father of all winds, rotation alone, however rapid, being unable to produce them."

They found this lake was about six times the size of Lake Superior, and that several large and small streams ran into its upper end. These had their sources in smaller lakes that were at slightly higher elevations. Though the air was cool, the sun shone brightly, while the ground was covered with flowers resembling those of the northern climes on earth, of all shapes and lines. Twice a day these sent up their song, and trees were covered with buds, and the birds twittered gaily. The streams murmured and bubbled, and all things reminded the travellers of early morning in spring.

"If anything could reconcile me," said Bearwarden, "to exchange my active utilitarian life for a rustic poetical existence, it would be this place, for it is far more beautiful than anything I have seen on earth. It needs but a Maud Muller and a few cows to complete the picture, since Nature gives us a vision of eternal peace and repose."

Somehow the mention of Maud Muller, and the delicate and refined flowers, whose perfume he inhaled, brought up thoughts that were never far below the surface in Ayrault's mind. "The place is heavenly enough," said he, "to make one wish to live and

remain here forever, but to me it would be Hamlet with Hamlet left out."

"Ah! poor chap," said Cortlandt, "you are in love, but you are not to be pitied, for though the thrusts at the heart are sharp, they may be the sweetest that mortals know."

The following morning they reluctantly left the picturesque shores of Lake Serenity, with their beautiful tints and foliage, and resumed the journey, to explore a number of islands in the ocean in the west, which were recorded on their negatives. Ascending to rarefied air, they saw great chains of mountains, which they imagined ran parallel to the coast, rising to considerable altitudes in the east. The tops of all glistened with a mantle of snow in the sunlight, while between the ridges they saw darker and evidently fertile valleys. They passed, moving northwest, over large and small lakes, all evidently part of the same great system, and continued to sweep along for several days with a beautiful panorama, as varying as a kaleidoscope, spread beneath their eyes. They observed that the character of the country gradually changed. The symmetrically rounded mountains and hills began to show angles, while great slabs of rock

were split from the faces. The sides also became less vertical, and there was an accumulation of detrital fragments about their bases. These heaps of fractured stone had in some cases begun to disintegrate and form soil, on which there was a scant growth of vegetation; but the sides and summits, whose jaggedness increased with their height, were absolutely bare.

"Here," said Cortlandt, "we have unmistakable evidence of frost and ice action. The next interesting question is, How recently has denudation occurred? The absence of plant life at the exposed places," he continued, as if lecturing to a class, "can be accounted for here, as nearer the equator, by the violence of the wind; but I greatly doubt whether water will now freeze in this latitude at any season of the year, for, even should the Northern hemisphere's very insignificant winter coincide with the planet's aphelion, the necessary drop from the present temperature would be too great to be at all probable. If, then, it is granted that ice does not form here now, notwithstanding the fact that it has done so, the most plausible conclusion is that the inclination of Jupiter's axis is automatically changing, as we know the earth's has often done. There being nothing incompatible

in this view with the evidence at hand, we can safely assume it correct for the time being at least. When farther south, you remember, we found no trace of ice action, notwithstanding the comparative slowness with which we decided that the ridges in the crust had been upheaved on account of the resisting power of gravity, and, as I see now, also on account of Jupiter's great mass, which must prevent its losing its heat anything like as fast as the earth has, in which I think also we have the explanation of the comparatively low elevation of the mountains that we found we could not account for by the power of gravitation alone. From the fact that the exposed surface farther south must be old, on account of the slow upheaval and the slight wear to which it is exposed, about the only wearing agent being the wind, which would be powerless to erase ice-scratches, especially since, on account of gravity's power, it cannot, like our desert winds, carry much sand — which, as we know, has cut away the base of the Sphinx — I think it is logical to conclude that, though Jupiter's axis is changing naturally as the earth's has been, it has never varied as much as twenty-three and a half degrees, and certainly to nothing like the extent to which we see Venus and Uranus tilted to-day."

"I follow you," said Bearwarden, "and do not see how we could arrive at anything else. From Jupiter's low specific gravity, weighing but little more than an equal bulk of water, I should say the interior must be very hot, or else is composed of light material, for the crust's surface, or the part we see, is evidently about as dense as what we have on earth. These things have puzzled me a good deal, and I have been wondering if Jupiter may not have been formed before the earth and the smaller planets."

"The discrepancies between even the best authorities," replied Cortlandt, "show that as yet but little has been discovered from the earth concerning Jupiter's real condition. The two theories that try to account for its genesis are the ring theory and the nebulous. We know that the sun is constantly emitting vast volumes of heat and light, and that, with the exception

of the heat resulting from the impact of falling meteors, it receives none from outside, the principal source being the tremendous friction and pressure between the cooling and shrinking strata within the great mass of the sun itself. A seeming paradox therefore comes in here, which must be considered: If the sun were composed entirely of gas, it would for a time continue to grow hotter; but the sun is incessantly radiating light and heat, and consequently becoming smaller. Therefore the farther back we go the hotter we find the sun, and also the larger, till, instead of having a diameter of eight hundred and eighty thousand miles, it filled the space now occupied by the entire solar system. Here is where the two theories start. According to the first, the revolving nebulous mass threw off a ring that became the planet Neptune, afterwards another that contained the material for Uranus, and so on, the lightest substance in the sun being thrown off first, by which they accounted for the lightness of the four great planets, and finally Mars, the earth, and the small dense planets near the sun. The advocates of this theory pointed to Saturn's rings as an illustration of the birth of a planet, or, rather, in that case a satellite. According to this, the major planets have had a far longer separate existence than the minor, which would account for their being so advanced notwithstanding their size. This theory may again come into general acceptance, but for the present it has been discredited by the nebulous. According to this second theory, at the time the sun filled all the space inside of Neptune's, orbit, or extended even farther, several centres of condensation were formed within the nebulous, gaseous mass. The greatest centre became the sun, and the others, large and small, the planets, which — as a result of the spiral motion of the whole, such as is now going on before our eyes in the great nebulae of fifty-one M. Canuin venaticorum, and many others — began to revolve about the greatest central body of gas. As the separate masses cooled, they shrank, and their surfaces or extreme edges, which at first were contiguous, began to recede, which recession is still going on with some rapidity on the part of the sun, for we may be sure its diameter diminishes as its density increases. According to either theory, as I see it, the major planets, on account of their distance from the central mass, have had longer separate existences than the minor, and are therefore more advanced than they would be had all been formed at the same time.

"This theory explains the practical uniformity in the chemical composition of all members of this system by assuming that they were all once a part of the same body, and you may say brothers and sisters of the sun, instead of its offspring. It also makes size the only factor determining temperature and density, but of course modified by age, since otherwise Jupiter would have a far less developed crust than that with which we find it. I have always considered the period from the molten condition to that with a crust as comparatively short, which stands to reason, for radiation has then no check; and the period from the formation of the crust, which acts as a blanket, to the death of a planet, as very long. I have not found this view clearly set forth in any of the books I have read, but it seems to me the simplest and most natural explanation. Now, granted that the solar system was once a nebula, on which I think every one will agree — the same forces that changed it into a system of sun and planets must be at work on fifty-one M. Canum venaticorum, Andromeda, and ninety-nine M. Virginis,

and must inevitably change them to suns, each with doubtless a system of planets.

"If, then, the condition of a nebula or star depends simply on its size, it is reasonable to suppose that Andromeda, Sirius, and all the vast bodies we see, were created at the same time as our system, which involves the necessity of one general and simultaneous creation day. But as Sirius, with its diameter of twelve million miles, must be larger than some of the nebulae will be when equally condensed, we must suppose rather that nebulae are forming and coming into the condition of bright and dead stars, much as apples or pears on a fruit tree are constantly growing and developing, so that the Mosaic description of the creation would probably apply in point of time only to our system, or perhaps to our globe, though the rest will doubtless pass through precisely the same stages. This, I think, I will publish, on our return, as the Cortlandt astronomical doctrine, as the most rational I have seen devised, and one that I think we may safely believe, until, perhaps, through increased knowledge, it can be disproved."

After they crossed a line of hills that ran at

right angles to their course they found the country more rolling. All streams and water-courses flowed in their direction, while their aneroid showed them that they were gradually descending. When they were moving along near the surface of the ground, a delicious and refined perfume exhaled by the blue and white flowers, that had been growing smaller as they journeyed northward, frequently reached their nostrils. To Cortlandt and Bearwarden it was merely the scent of a flower, but to Ayrault it recalled mental pictures of Sylvia wearing violets and lilies that he had given her. He knew that the greatest telescopes on earth could not reveal the Callisto moving about in Jupiter's sunshine, as even a point of light, at that distance, and, notwithstanding Cortlandt's learning and Bearwarden's joviality, he felt at times extremely lonely.

They swept along steadily for fifty hours, having bright sunny days and beautifully moonlit nights. They passed over finely rounded hills and valleys and well-watered plains. As they approached the ocean and its level the temperature rose, and there was more moisture in the air. The plants and flowers also increased in size, again resembling some

what the large species they had seen near the equator.

"This would be the place to live," said Bearwarden, looking at iron mountains, silver, copper, and lead formations, primeval forests, rich prairies, and regions evidently underlaid with coal and petroleum, not to mention huge beds of aluminum clay, and other natural resources, that made his materialistic mouth water. "It would be joy and delight to develop industries here, with no snow avalanches to clog your railroads, or icy blizzards to paralyze work, nor weather that blights you with sun-strokes and fevers. On our return to the earth we must organize a company to run regular interplanetary lines. We could start on this globe all that is best on our own. Think what boundless possibilities may be before the human race on this planet, which on account of its vast size will be in its prime when our insignificant earth is cold and dead and no longer capable of supporting life! Think also of the indescribable blessing to the congested communities of Europe and America, to find an unlimited outlet here! Mars is already past its prime, and Venus scarcely habitable, but in Jupiter we have a new promised land, compared

with which our earth is a pygmy, or but little more than microscopic."

"I see," said Ayrault, "that the possibilities here have no limit; but I do not see how you can compare it to the promised land, since, till we undertook this journey, no one had even thought of Jupiter as a habitable place."

"I trace the Divine promise," replied Bearwarden, "in what you described to us on earth as man's innate longing and desire to rise, and in the fact that the Almighty has given the race unbounded expansiveness in very limited space. This would look to me as the return of man to the garden of Eden through intellectual development, for here every man can sit under his own vine and fig-tree."

"It seems to me," said Cortlandt, "that no paradise or heaven described in anything but the Bible compares with this. According to Virgil's description, the joys on the banks of his river Lethe must have been most sad and dreary, the general idleness and monotony apparently being broken only by wrestling matches between the children, while the rest strolled about with laurel wreaths or rested in the shade. The pilot Palinurus, who had been drowned by falling

overboard while asleep, but who before that had presumably done his duty, did not seem especially happy; while the harsh, resentful disposition evidently remained unsoftened, for Dido became like a cliff of Marpesian marble when AEneas asked to be forgiven, though he had doubtless considered himself in duty bound to leave her, having been twice commanded to do so by Mercury, the messenger of Jove. She, like the rest, seems to have had no occupation, while the consciences of few appear to have been sufficiently clear to enable them to enjoy unbroken rest."

"The idleness in the spirit-land of all profane writers," added Bearwarden, "has often surprised me too. Though I have always recommended a certain amount of recreation for my staff — in fact, more than I have generally had myself — an excess of it becomes a bore. I think that all real progress comes through thorough work. Why should we assume that progress ceases at death? I believe in the verse that says, `We learn here on earth those things the knowledge of which is perfected in heaven.'"

"According to that," said Cortlandt, "you will some day be setting the axis of heaven right, for in

order to do work there must be work to be done — a necessary corollary to which is that heaven is still imperfect."

"No," said Bearwarden, bristling up at the way Cortlandt sometimes received his speeches, "it means simply that its development, though perfect so far as it goes, may not be finished, and that we may be the means, as on earth, of helping it along."

"The conditions constituting heaven," said Ayrault, "may be as fixed as the laws of Nature, though the products of those conditions might, it seems to me, still be forming and subject to modification thereby. The reductio ad absurdum would of course apply if we supposed the work of creation absolutely finished."

2.13. NORTH-POLAR DISCOVERIES.

Two days later, on the western horizon, they beheld the ocean. Many of the streams whose sources they had seen when they crossed the divide from the lake basin, and whose courses they had followed, were now rivers a mile wide, with the tide ebbing and rising within them many hundreds of miles from their mouths. When they reached the shore line they found the waves breaking, as on earth, upon the sands, but with this difference: they had before noted the smallness of the undulations compared with the strength of the wind, the result of the water's weight. These waves now reminded them of the behaviour of mercury, or of melted lead when stirred on earth, by the rapidity with which the crests dropped. Though the wind was blowing an on-shore gale, there was but little combing, and when

there was any it lasted but a second. The one effort of the crests and waves seemed to be to remain at rest, or, if stirred in spite of themselves, to subside.

When over the surface of the ocean, the voyagers rose to a height of thirty thousand metres, and after twenty-four hours' travelling saw, at a distance of about two hundred miles, what looked like another continent, but which they knew must be an island. On finding themselves above it, they rose still higher to obtain a view of its outlines and compare its shape with that of the islands in the photographs they had had time to develop. The length ran from southeast to northwest. Though crossed by latitude forty, and notwithstanding Jupiter's distance from the sun, the southern side had a very luxuriant vegetation that was almost semi-tropical. This they accounted for by its total immunity from cold, the density of the air at sea-level, and the warm moist breezes it received from the tepid ocean. The climate was about the same as that of the Riviera or of Florida in winter, and there was, of course, no parching summer.

"This shows me," said Bearwarden, "that a country's climate depends less on the amount of heat

it receives from the sun than on the amount it retains; proof of which we have in the tops of the Himalayas perpetually covered with snow, and snow-capped mountains on the very equator, where they get the most direct rays, and where those rays have but little air to penetrate. It shows that the presence of a substantial atmosphere is as necessary a part of the calculation in practice as the sun itself. I am inclined to think that, with the constant effect of the internal heat on its oceans and atmosphere, Jupiter could get along with a good deal less solar heat than it receives, in proof of which I expect to find the poles themselves quite comfortable. The reason the internal heat is so little taken into account on earth is because, from the thickness of the crust, it cannot make itself felt; for if the earth were as chilled through as ice, the people on the surface would not feel the difference."

A Jovian week's explorations disclosed the fact that though the island's general outlines were fairly regular, it had deep-water harbours, great rivers, and land-locked gulfs and bays, some of which penetrated many hundred miles into the interior. It also showed that the island's length was about six thou

sand miles, and its breadth about three thousand, and that it had therefore about the superficial area of Asia. They found no trace of the great monsters that had been so numerous on the mainland, though there were plenty of smaller and gentle-looking creatures, among them animals whose build was much like that of the prehistoric horse, with undeveloped toes on each side of the hoof, which in the modern terrestrial horse have disappeared, the hoof being in reality but a rounded-off middle finger.

"It is wonderful," said Bearwarden, "how comparatively narrow a body of water can keep different species entirely separate. The island of Sumatra, for instance, is inhabited by marsupials belonging to the distinct Australian type, in which the female, as in the kangaroo, carries the slightly developed young in a pouch; while the Malay peninsula, joined to the mainland, has all the highly developed animals of Asia and the connected land of the Eastern hemisphere, the narrow Malacca Strait being all that has kept marsupials and mammals apart, though the separating power has been increased by the rapid current setting through. This has decreased the chance of creatures carried to sea on drift-wood or

uprooted trees getting safely over to such a degree that apparently none have survived; for, had they done so, we may be certain that the mammals, with the advantage their young have over the marsupials, would soon have run them out, the marsupials being the older and the less perfect form of life of the two."

Before leaving the beautiful sea-girt region beneath them, Cortlandt proposed that it be named after their host, which Bearwarden seconded, whereupon they entered it as Ayrault Island on the charts. After this they rose to a great height, and flew swiftly over three thousand miles of ocean till they came to another island not quite as large as the first. It was four thousand five hundred miles long by something less than three thousand wide, and was therefore about the size of Africa. It had several high ranges of mountains and a number of great rivers and fine harbours, while murmuring, bubbling brooks flowed through its forest glades. There were active volcanoes along the northern coast, and the blue, crimson, and purple lines in the luxuriant foliage were the most beautiful they had ever seen.

"I propose," said Bearwarden, "that we christen this Sylvialand." This Cortlandt immediately seconded, and it was so entered on the charts.

"These two islands," said Bearwarden, "may become the centres of civilization. With flying machines and cables to carry passengers and information, and ships of great displacement for the interchange of commodities, there is no limit to their possible development. The absence of large waves will also be very favourable to sea-spiders, which will be able to run at tremendous speeds. The constancy in the eruptions of the volcanoes will offer a great field to Jovian inventors, who will unquestionably be able to utilize their heat for the production of steam or electricity, to say nothing of an inexhaustible supply of valuable chemicals. They may contain the means of producing some force entirely different from apergy, and as superior to electricity as that is to steam. Our earthly volcanoes have been put to slight account because of the long intervals between eruptions."

After leaving Sylvialand they went westward to the eastern of the two crescent continents. It was separated from the island by about six thousand

miles of ocean, and had less width than the western, having about the proportions of a three-day crescent, while the western had the shape of the moon when four or five days old. They found the height of the mountains and plateaus somewhat less than on the eastern continent, but no great difference in other respects, except that, as they went towards the pole, the vegetation became more like that of Scotland or a north temperate region than any they had seen. On reaching latitude fifty they again came out over the ocean to investigate the speckled condition they had observed there. They found a vast archipelago covering as great an area as the whole Pacific Ocean. The islands varied from the size of Borneo and Madagascar to that of Sicily and Corsica, while some contained but a few square miles. The surface of the archipelago was about equally divided between land and water.

"It would take good navigation or an elaborate system of light-houses," said Bearwarden, "for a captain to find the shortest course through these groups."

The islands were covered with shade trees much resembling those on earth, and the leaves on many

were turning yellow and red, for this hemisphere's autumn had already begun.

"The Jovian trees," said Cortlandt, "can never cease to bear, though the change of seasons is evidently able to turn their colour, perhaps by merely ripening them. When a ripe leaf falls off, its place is doubtless soon taken by a bud, for germination and fructification go on side by side."

Before leaving, they decided to name this Twentieth Century Archipelago, since so much of the knowledge appertaining to it had been acquired in their own day. At latitude sixty the northern arms of the two continents came within fifteen hundred miles of each other. The eastern extension was split like the tail of a fish, the great bay formed thereby being filled with islands, which also extended about half of the distance across. The western extremity shelved very gradually, the sand-bars running out for miles just below the surface of the water.

After this the travellers flew northward at great speed in the upper regions of the air, for they were anxious to hasten their journey. They found nothing but unbroken sea, and not till they reached latitude eighty-seven was there a sign of ice. They then saw

some small bergs and field ice, but in no great quantities. As their outside thermometer, when just above the placid water — for there were no waves here — registered twenty-one degrees Fahrenheit, they accounted for this scarcity of ice by the absence of land on which fresh water could freeze, and by the fact that it was not cold enough to congeal the very salt sea-water.

Finally they reached another archipelago a few hundred miles in extent, the larger islands of which were covered with a sheet of ice, at the edges of which small icebergs were being formed by breaking off and slowly floating. Finding a small island on which the coating was thin, they grounded the Callisto, and stepped out for the first time in several days. The air was so still that a small piece of paper released at a height of six feet sank slowly and went as straight as the string of a plumb-line. The sun was bisected by the line of the horizon, and appeared to be moving about them in a circle, with only its upper half visible. As Jupiter's northern hemisphere was passing through its autumnal equinox, they concluded they had landed exactly at the pole.

"Now to work on our experiment," said Cortlandt.

"I wonder how we may best get below the frozen surface?"

"We can explode a small quantity of dynamite," replied Bearwarden, "after which the digging will be comparatively easy."

While Cortlandt and Bearwarden prepared the mine, Ayrault brought out a pickaxe, two shovels, and the battery and wires with which to ignite the explosive. They made their preparations within one hundred feet of the Callisto, or much nearer than an equivalent amount of gunpowder could have been discharged.

"This recalls an old laboratory experiment, or rather lecture," said Cortlandt, as they completed the arrangements, "for the illustration is not as a rule carried out. Explode two pounds of powder on an iron safe in a room with the windows closed, and the windows will be blown out, while the safe remains uninjured. Explode an equivalent amount of dynamite on top of the safe, and it will be destroyed, while the glass panes are not even cracked. This illustrates the difference in rapidity with which the explosions take place. To the intensely rapid action of dynamite the air affords as much resistance as a

solid substance, while the explosion of the powder is so slow that the air has time to move away; hence the destruction of the windows in the first case, and the safe in the second."

When they had moved beyond the danger line, Bearwarden, as the party's practising engineer, pressed the button, and the explosion did the rest. They found that the ground was frozen to a depth of but little more than a foot, below which it became perceptibly warm. Plying their shovels vigorously, they had soon dug the hole so deep that its edges were above their heads. When the floor was ten feet below the surrounding level the thermometer registered sixty.

"This is scarcely a fair test," said Cortlandt, "since the heat rises and is lost as fast as given off. Let us therefore close the opening and see in what time it will melt a number of cubic feet of ice."

Accordingly they climbed out, threw in about a cart-load of ice, and covered the opening with two of the Callisto's thick rugs. In half an hour all the ice had melted, and in another half hour the water was hot.

"No arctic expedition need freeze to death here," said Bearwarden, since all a man would have to do would be to burrow a few feet to be as warm as toast."

As the island on which they had landed was at one side of the archipelago, but was itself at the exact pole, it followed that the centre of the archipelago was not the part farthest north. This in a measure accounted for the slight thickness of ice and snow, for the isobaric lines would slope, and consequently what wind there was would flow towards the interior of the archipelago, whose surface was colder than the surrounding ocean. The moist air, however, coming almost entirely from the south, would lose most of its moisture by condensation in passing over the ice-laden land, and so, like the clouds over the region east of the Andes, would have but little left to let fall on this extreme northern part. The blanketing effect of a great thickness of snow would also cause, the lower strata of ice to melt, by keeping in the heat constantly given off by the warm planet.

"I think there can be no question," said Cortlandt, "that, as a result of Jupiter's great flattening

at the poles and the drawing of the crust, which moves faster in Jupiter's rotation than any other part, towards the equator, the crust must be particularly thin here; for, were it as thin all over, there would be no space for the coal-beds, which, judging from the purity of the atmosphere, must be very extensive. Further, we can recall that the water in the hot spring near which we alighted, which evidently came from a far greater depth than we have here, was not as hot as this. The conclusion is clear that elsewhere the internal heat is not as near the surface as here."

"The more I see of Jupiter," exclaimed Bearwarden enthusiastically, "the more charmed I become. It almost exactly supplies what I have been conjuring up as my idea of a perfect planet. Its compensations of high land near the equator, and low with effective internal heat at the poles, are ideal. The gradual slope of its continental elevations, on account of their extent, will ease the work of operating railways, and the atmosphere's density will be just the thing for our flying machines, while Nature has supplied all sources of power so lavishly that no undertaking will be too great. Though land as yet, to

judge by our photographs, occupies only about one eighth of the surface, we know, from the experience of the other planets, that this is bound to increase; so that, if the human race can perpetuate itself on Jupiter long enough, it will undoubtedly have one fourth or a larger proportion for occupation, though the land already upheaved comprises fully forty times the area of our entire globe, which, as we know, is still three fourths water."

Since we have reached what we might call the end of Jupiter, and still have time, continued Ayrault, "let us proceed to Saturn, where we may find even stranger things than here. I hoped we could investigate the great red spot, but am convinced we have seen the beginning of one in Twentieth Century Archipelago, and what, under favourable conditions, will be recognized as such on earth."

It was just six terrestrial weeks since they had set out, and therefore February 2d on earth.

"It would be best, in any case, to start from Jupiter's equator," said Cortlandt, "for the straight line we should make from the surface here would be at right angles to Saturn. We shall probably, in spite of ourselves, swing a few degrees beyond the

line, and so can get a bird's-eye view of some portion of the southern hemisphere."

"All aboard for Saturn!" cried Bearwarden enthusiastically, in his jovial way. "This will be a journey."

2.14. THE SCENE SHIFTS.

Having returned the rugs to the Callisto, they applied the maximum power of the batteries to rising, closed all openings when the barometer registered thirty, and moved off into space. When Several thousand miles above the pole, they diverted part of the power to attracting the nearest moon that was in the plane of Jupiter's equator, and by the time their upward motion had ceased were moving well in its direction. Their rapid motion aided the work of resisting gravity, since their car had in fact become a small moon, revolving, like those of Uranus or that of Neptune, in an orbit varying greatly from the plane of the ecliptic. As they flew south at a height ranging from two thousand to three thousand miles, the planet revolved before them, and they had a chance of obtaining a thorough view. There were but a few

scattered islands on the side of the Northern hemisphere opposite to that over which they had reached the pole, and in the varying colours of the water, which they attributed to temperature or to some substance in solution, they recognized what they had always heard described on earth as the bands of Jupiter, encircling the planet with great belts, the colour varying with the latitude. At about latitude forty-five these bands were purple, farther south light olive green, and at the equator a brown orange. Shortly after they swung across the equator the ocean again became purple, and at the same time a well-defined and very brilliant white spot came into view. Its brightness showed slight variations in intensity, though its general shape remained unchanged. It had another peculiarity, in that it possessed a fairly rapid motion of its own, as it moved eastward across the surface of the ocean. It exhibited all the phenomena of the storm they had watched in crossing Secretary Deepwaters Bay, but covered a larger area, and was far more violent. Their glasses showed them vast sheets of spray driven along at tremendous speed, while the surface was milky white.

""This," said Bearwarden, picking up a book,

"solves to my mind the mystery of the white spot described by the English writer Chambers, in 1889, as follows:

"`During the last few years a brilliant white spot has been visible on the equatorial border of the great southern belt. A curious fact in connection with this spot is, that it moves with a velocity of some two hundred and sixty miles per hour greater than the red spot. Denning obtained one hundred and sixty-nine observations of this bright marking during the years 1880-1883, and determined the period as nine hours, fifty minutes, eight and seven tenths seconds (five and a half minutes less than that of the red spot). Although the latter is now somewhat faint, the white spot gives promise of remaining visible for many years. During the year 1886 a large number of observations of Jupiter were made at the Dearborn Observatory, Chicago, U. S., by Prof. G. W. Hough, using the eighteen-and-a-half-inch refractor of the observatory. Inasmuch as these observations are not only of high intrinsic interest, but are in conflict, to some extent, with previous records, a somewhat full abstract of them will be useful: The object of general interest was the great red spot. The outline,

shape, and size of this remarkable object has remained without material change from the year 1879, when it was first observed here, until the present time. According to our observations, during the whole of this period it has shown a sharp and well-defined outline, and at no time has it coalesced or been joined to any belt in its proximity, as has been alleged by some observers. During the year 1885 the middle of the spot was very much paler in colour than the margins, causing it to appear as an elliptical ring. The ring form has continued up to the present time. While the outline of the spot has remained very constant, the colour has changed materially from year to year. During the past three years (1884-'86) it has at times been very faint, so as barely to be visible. The persistence of this object for so many years leads me to infer that the formerly accepted theory, that the phenomena seen on the surface of the planet are atmospheric, is no longer tenable. The statement so often made in text-books, that in the course of a few days or months the whole aspect of the planet may be changed, is obviously erroneous. The oval white spots on the southern hemisphere of the planet, nine degrees south of the equator, have been systematically observed at every opposition during the past eight years. They are generally found in groups of three or more, but are rather difficult to observe. The rotation period deduced from them is nearly the same as from the great red spot. These spots usually have a slow drift in longitude of about five seconds daily in the direction of the planet's rotation, when referred to the great red spot; corresponding to a rotation period of twenty seconds less than the latter.'

"This shows," continued Bearwarden, "that as long ago as towards the close of the nineteenth century the old idea that we saw nothing but the clouds in Jupiter's atmosphere was beginning to change; and also how closely the two English writers and Prof. Hough were studying the subject, though their views did not entirely agree. A white spot is merely a storm-centre passing round and round the planet, the wind running a little ahead of the surface, which accounts for its rapid rotation compared with the red spot, which is a fixture. A critic may say we have no such winds on earth; to which I reply, that winds on a planet of Jupiter's size, with its rate of rotation — though it is 480,000,000 miles from the sun and

the internal heat is so near the surface — and with land and water arranged as they are, may and indeed must be very different from those prevailing on earth, the conditions producing and affecting them being so changed. Though the storm-centre moves two hundred and sixty miles an hour, the wind need not blow at that rate."

Later they saw several smaller spots drifting eastward, but concluded that any seaworthy ship might pass safely through them, for, though they were hurricanes of great violence, the waves were small.

"There would be less danger," said Bearwarden, "of shipping seas here than there is on earth; the principal risk to travellers would be that of being blown from the deck. On account of the air's weight in connection with its velocity, this would necessitate some precaution."

The next object of interest was the great red spot. It proved, as Cortlandt had predicted, to be a continent, with at that time no special colour, though they easily recognized it by comparing its outlines with those of the spot in the map. Its length, as they already knew, was twenty-seven thousand miles,

and its breadth about eight thousand miles, so that it contained more square miles than the entire surface of the earth, land and water included.

"It is clear," said Cortlandt, "that at some season of Jupiter's long year a change takes place that affects the colour of the leaves — some drought or prolonged norther; for it is obvious that that is the simplest explanation. In like manner we may expect that at some times more white spots will move across the ocean than at others."

"On account of the size of these continents and oceans," said Bearwarden, "it is easy to believe that many climatic conditions may prevail here that can scarcely exist on earth. But what a magnificent world to develop, with its great rivers, lakes, and mountains showing at even this distance, and what natural resources must be lying there dormant, awaiting our call! This constantly recurs to my mind. The subjugation and thorough opening up of this red spot continent will probably supply more interesting problems than straightening the axis of the earth."

"At our next visit," replied Ayrault, "when we have established regular interplanetary lines of

travel, we may have an opportunity to examine it more closely."

Then they again attracted the nearest moon beyond which they had swung, increased the repulsion on Jupiter, and soared away towards Saturn.

"We have a striking illustration of Jupiter's enormous mass," said Cortlandt, as the apparent diameter of the mighty planet rapidly decreased, "in the fact that notwithstanding its numerous moons, it still rotates so rapidly. We know that the earth's days were formerly but half or a quarter as long as now, having lasted but six or eight hours. The explanation of the elongation is simple: the earth rotates in about twenty-four hours, while the moon encircles it but once in nearly twenty-eight days, so that our satellite is continually drawing the oceans backward against its motion. These tidal brakes acting through the friction of the water on the bottom, its unequal pressure, and the impact of the waves on the shore, are continually retarding its rotation, so that the day is a fraction of a second longer now than it was in the time of Caesar. This same action is of course taking place in Jupiter and the great planets, in this case there being five moons at work. Our moon, we

know, rotates on its axis but once while it revolves about the earth, this being no doubt due to its own comparative smallness and the great attraction of the earth, which must have produced tremendous tides before the lunar oceans disappeared from its surface."

In crossing the orbits of the satellites, they passed near Ganymede, Jupiter's largest moon.

"This," said Cortlandt, "was discovered by Galileo in 1610. It is three thousand four hundred and eighty miles in diameter, while our moon is but two thousand one hundred and sixty, revolves at a distance of six hundred and seventy-eight thousand three hundred miles from Jupiter, completes its revolution in seven days and four hours, and has a specific gravity of 1.87."

In passing, they observed that Ganymede possessed an atmosphere, and continents and oceans of large area.

"Here," said Bearwarden, "we have a body with a diameter about five hundred miles greater than the planet Mercury. Its size, light specific gravity, atmosphere, and oceans seem to indicate that it is less advanced than that planet, yet you think Jupiter has

had a longer separate existence than the planets nearer the sun?"

"Undoubtedly," said Cortlandt. "Jupiter was condensed while in the solar-system nebula, and began its individual existence and its evolutionary career long before Mercury was formed. The matter now in Ganymede, however, doubtless remained part of the Jupiter-system nebula till after Mercury's creation, and, being part of so great a mass, did not cool very rapidly. I should say that this satellite has about the same relation to Jupiter that Jupiter has to the sun, and is therefore younger in point of time as well as of development than the most distant Callisto, and older, at all events in years, than Europa and Io, both of which are nearer. This supposition is corroborated by the fact that Europa, the smallest of these four, is also the densest, having a specific gravity of 2.14, its smallness having enabled it to overtake Ganymede in development, notwithstanding the latter's start. In the face of the evidence before us we must believe this, or else that, perhaps, as in the case of the asteroid Hilda, something like a collision has rejuvenated it. This might account for its size, and for the Nautical Almanac's statement that there is a

`small and variable' inclination to its orbit, while Io and Europa revolve exactly in the plane of Jupiter's equator."

They had about as long a journey before them as they had already made in going from the earth to Jupiter. The great planet soon appeared as a huge crescent, since it was between them and the sun; its moons became as fifth-and sixth-magnitude stars, and in the evening of the next day Jupiter's disk became invisible to the unaided eye. Since there were no way stations, in the shape of planets or asteroids, between Jupiter and Saturn, they kept the maximum repulsion on Jupiter as long as possible, and moved at tremendous speed. Saturn was somewhat in advance of Jupiter in its orbit, so that their course from the earth had been along two sides of a triangle with an obtuse angle between. During the next four terrestrial days they sighted several small comets, but spent most of their time writing out their Jovian experiences. During the sixth day Saturn's rings, although not as much tilted as they would be later in the planet's season, presented a most superb sight, while they spun in the sun's rays. Soon after this the eight moons became visible, and, while slightly

reducing the Callisto's speed, they crossed the orbits of Iapetus, Hyperion, and Titan, when they knew they were but seven hundred and fifty thousand miles from Saturn.

"I am anxious to ascertain," said Cortlandt, "whether the composition of yonder rings is similar to that of the comet through which we passed. I am sure they shine with more than reflected light."

"We have been in the habit," said Ayrault, "of associating heat with light, but it is obvious there is something far more subtle about cometary light and that of Saturn's rings, both of which seem to have their birth in the intense cold of interplanetary space."

Passing close to Mimas, Saturn's nearest moon, they supplemented its attraction, after swinging by, by their own strong pull, bringing their speed down to dead slow as they entered the outside ring. At distances often of half a mile they found meteoric masses, sometimes lumps the size of a house, often no larger than apples, while small particles like grains of sand moved between them. There were two motions. The ring revolved about Saturn, and the particles vibrated among themselves, evidently kept

apart by a mutual repulsion, which seemed both to increase and decrease faster than gravitation; for on approaching one another they were more strongly repelled than attracted, but when they separated the repulsion decreased faster than the attraction, so that after a time divergence ceased, and they remained at fixed distances.

The Callisto soon became imbued with motion also, but nothing ever struck it. When any large mass came unusually near, both it and their car emitted light, and they rapidly separated. The sunlight was not as strong here as it had been when they entered the comet, and as they penetrated farther they were better able to observe the omnipresent luminosity. They were somewhat puzzled by the approach of certain light-centres, which seemed to contain nothing but this concentrated brightness. Occasionally one of these centres would glow very brightly near them, and simultaneously recede. At such times the Callisto also glowed, and itself recoiled slightly. At first the travellers could not account for this, but finally they concluded that the centres must be meteoric masses consisting entirely of gases, possessing weight though invisible.

"We have again to face," said Cortlandt, "that singular law that till recently we did not suppose existed on earth. All kinds of suppositions have been advanced in explanation of these rings. Some writers have their thickness, looked at from the thin edge, as four hundred miles, some one hundred, and some but forty. One astronomer of the nineteenth century, a man of considerable eminence, was convinced that they consisted of sheets of liquid. Now, it should be obvious that no liquid could maintain itself here for a minute, for it would either fall upon the planet as a crushing hail, or, if dependent for its shape on its own tenacity, it would break if formed of the toughest steel, on account of the tremendous weight. Any number of theories have been advanced by any number of men, but in weight we have the rub. No one has ever shown how these innumerable fragments maintain themselves at a height of but a few thousand miles above Saturn, withstanding the giant's gravitation-pull. Their rate of revolution, though rapid, does not seem fast enough to sustain them. Neither have I ever seen it explained why the small fragments do not fall upon the large ones, though many astronomers have pictured the

composition of these rings as we find they exist. Nor do we know why the molecules of a gas are driven farther apart by heat, while their activity is also increased, though if this activity were revolution about one another to develop the centrifugal, it would not need to be as strong then as when they are cold and nearer together. There may be explanations, but I have found none in any of the literature I have read. It seems to me that all this leads to but one conclusion, viz.: apergy is the constant and visible companion of gravitation, on these great planets Jupiter and Saturn, perhaps on account of some peculiar influence they possess, and also in comets, in the case of large masses, while on earth it appears naturally only among molecules — those of gases and every other substance."

"I should go a step further," said Bearwarden, "and say our earth has the peculiarity, since it does not possess the influence necessary to generate naturally a great or even considerable development of apergy. The electricity of thunderstorms, northern lights, and other forces seems to be produced freely, but as regards apergy our planet's natural productiveness appears to be small."

The omnipresent luminosity continued, but the glow was scarcely bright enough to be perceived from the earth.

"I believe, however," said Bearwarden, referring to this, "that whenever a satellite passes near these fragments, preferably when it enters the planet's shadow, since that will remove its own light, it will create such activity among them as to make the luminosity visible to the large telescopes or gelatine plates on earth."

"Now," said Ayrault, "that we have evolved enough theories to keep astronomers busy for some time, if they attempt to discuss them, I suggest that we alight and leave the abstract for the concrete."

Whereupon they passed through the inner ring and rapidly sank to the ground.