Part 13 (1/2)
When near the great lake's upper end, they pa.s.sed the mouth of a river on their left side, which, from its volume, they concluded must be the princ.i.p.al 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 canyon.
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 canyon, 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 pa.s.sing 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 pa.s.sage, 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.
CHAPTER XII.
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 canyon 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 ma.s.s 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 sh.o.r.es 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 a.n.a.lysis 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 a.s.suming 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 pa.s.sed 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 lat.i.tude, 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 sh.o.r.es 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 alt.i.tudes 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 pa.s.sed, 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 acc.u.mulation 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 cla.s.s, ”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 lat.i.tude 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 a.s.sume 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 ma.s.s, 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.[2]
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 Ura.n.u.s tilted to-day.”
[2] It is well known that mountain chains are but ridges or foldings in the crust upheaved as the interior cools and shrinks. This is proved by reason and by experiments with viscous clay or other material placed upon a sheet of stretched rubber, which is afterwards allowed to contract, whereupon the a.n.a.logues of mountain ridges are thrown up.