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 thirtytwo 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.