A Journey in Other Worlds Part 14

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 pa.s.sengers 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 lat.i.tude 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 lat.i.tude 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 lat.i.tude eighty-seven was there a sign of ice. They then saw some small bergs and field ice, but in no great quant.i.ties. 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 pa.s.sing 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 quant.i.ty 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 ill.u.s.tration 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 gla.s.s panes are not even cracked. This ill.u.s.trates 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 b.u.t.ton, 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 pa.s.sing 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 s.p.a.ce 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."

CHAPTER XIV.

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 s.p.a.ce. 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 Ura.n.u.s 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 lat.i.tude. At about lat.i.tude 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 gla.s.ses 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 pa.s.sing 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 pa.s.s 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 princ.i.p.al 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 ill.u.s.tration of Jupiter's enormous ma.s.s," 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 sh.o.r.e, are continually r.e.t.a.r.ding 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 pa.s.sed 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 pa.s.sing, 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 ma.s.s, 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...o...b..t, while Io and Europa revolve exactly in the plane of Jupiter's equator."