A Journey in Other Worlds [62]
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
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