"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 2.55times 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.
