A Journey in Other Worlds [63]
from the sea, by the fact that the rivers are all on the
surface, not having had time to cut down their channels below the
surrounding country. By similar reasoning, we know that the
canon of the Colorado is a very old region, though the
precipitateness of its banks is due to the absence of rain, for a
local water-supply would cut back the banks, having most effect
where they were steepest, since at those points it would move
with the greatest speed. Thus the majestic canon owes its
existence to two things: the length of time the river has been at
work, and the fact that the water flowing through it comes from
another region where, of course, there is rain, and that it is
merely in transit, and so affects only the bed on which it moves.
Granting that this is the eastern of the two continents we
observed, it evidently corresponds more in shape to the Eastern
hemisphere on earth than to the New World, both of which are set
facing one another, since both drain towards the Atlantic Ocean.
But the analogy here holds also, for the past outlines of the
Eastern hemisphere differed radically from what they are now.
The Mediterranean Sea was formerly of far greater extent than we
see it to-day, and covered nearly the whole of northern Africa
and the old upheaved sea-bottom that we see in the Desert of
Sahara. Much of this great desert, as we know, has a
considerable elevation, though part of it is still below the
level of the Mediterranean.
"Perhaps a more striking proof of this than are the remains of
fishes and marine life that are found there, is the dearth of
natural harbours and indentations in Africa's northern coast,
while just opposite, in southern Europe, there are any number;
which shows that not enough time has elapsed since Africa's
upheaval for liquid or congealed water to produce them. Many of
Europe's best harbours, and Boston's, in our country, have been
dug out by slow ice-action in the oft-recurring Glacial periods.
The Black and Caspian Seas were larger than we now find them;
while the Adriatic extended much farther into the continent,
covering most of the country now in the valley of the Po. In
Europe the land has, of course, risen also, but so slowly that
the rivers have been able to keep their channels cut down; proof
of their ability to perform which feat we see when an ancient
river passes through a ridge of hills or mountains. The river
had doubtless been there long before the mountains began to rise,
but their elevation was so gradual that the rate of the river's
cutting down equalled or exceeded their coming up; proof of which
we have in the patent fact that the ancient river's course
remains unchanged, and is at right angles to the mountain chain.
From all of which we see that the Eastern hemisphere's crescent
hollow--of which, I take it, the Mediterranean, Black, and
Caspian Sea depressions are the remains--has been gradually
filled in, by the elevation of the sea's bottom, and the
extension of deltas from the detrital matter brought from the
high interior of the continents by the rivers, or by the combined
action of the two. Now, since the Gulf of Mexico has been
constantly growing smaller, and the Mediterranean is being
invaded by the land, I reason that similar causes will produce
like effects here, and give to each continent an area far greater
than our entire globe. The stormy ocean we behold in the west,
which corresponds to our Atlantic, though it is far more of a
mare clausum in the geographical sense, is also destined to
become a calm and placid inland sea. There are, of course,
modifications of and checks to the laws tending to increase the
land area. England was formerly joined to the continent, the
land connecting the two having been rather washed away by the
waves and great tides than by any sinking of the English
Channel's bottom, the whole of which is comparatively shallow.
Another case of this kind is seen in Cape Cod and the islands of
Martha's Vineyard and Nantucket, all of which are washing away so
surface, not having had time to cut down their channels below the
surrounding country. By similar reasoning, we know that the
canon of the Colorado is a very old region, though the
precipitateness of its banks is due to the absence of rain, for a
local water-supply would cut back the banks, having most effect
where they were steepest, since at those points it would move
with the greatest speed. Thus the majestic canon owes its
existence to two things: the length of time the river has been at
work, and the fact that the water flowing through it comes from
another region where, of course, there is rain, and that it is
merely in transit, and so affects only the bed on which it moves.
Granting that this is the eastern of the two continents we
observed, it evidently corresponds more in shape to the Eastern
hemisphere on earth than to the New World, both of which are set
facing one another, since both drain towards the Atlantic Ocean.
But the analogy here holds also, for the past outlines of the
Eastern hemisphere differed radically from what they are now.
The Mediterranean Sea was formerly of far greater extent than we
see it to-day, and covered nearly the whole of northern Africa
and the old upheaved sea-bottom that we see in the Desert of
Sahara. Much of this great desert, as we know, has a
considerable elevation, though part of it is still below the
level of the Mediterranean.
"Perhaps a more striking proof of this than are the remains of
fishes and marine life that are found there, is the dearth of
natural harbours and indentations in Africa's northern coast,
while just opposite, in southern Europe, there are any number;
which shows that not enough time has elapsed since Africa's
upheaval for liquid or congealed water to produce them. Many of
Europe's best harbours, and Boston's, in our country, have been
dug out by slow ice-action in the oft-recurring Glacial periods.
The Black and Caspian Seas were larger than we now find them;
while the Adriatic extended much farther into the continent,
covering most of the country now in the valley of the Po. In
Europe the land has, of course, risen also, but so slowly that
the rivers have been able to keep their channels cut down; proof
of their ability to perform which feat we see when an ancient
river passes through a ridge of hills or mountains. The river
had doubtless been there long before the mountains began to rise,
but their elevation was so gradual that the rate of the river's
cutting down equalled or exceeded their coming up; proof of which
we have in the patent fact that the ancient river's course
remains unchanged, and is at right angles to the mountain chain.
From all of which we see that the Eastern hemisphere's crescent
hollow--of which, I take it, the Mediterranean, Black, and
Caspian Sea depressions are the remains--has been gradually
filled in, by the elevation of the sea's bottom, and the
extension of deltas from the detrital matter brought from the
high interior of the continents by the rivers, or by the combined
action of the two. Now, since the Gulf of Mexico has been
constantly growing smaller, and the Mediterranean is being
invaded by the land, I reason that similar causes will produce
like effects here, and give to each continent an area far greater
than our entire globe. The stormy ocean we behold in the west,
which corresponds to our Atlantic, though it is far more of a
mare clausum in the geographical sense, is also destined to
become a calm and placid inland sea. There are, of course,
modifications of and checks to the laws tending to increase the
land area. England was formerly joined to the continent, the
land connecting the two having been rather washed away by the
waves and great tides than by any sinking of the English
Channel's bottom, the whole of which is comparatively shallow.
Another case of this kind is seen in Cape Cod and the islands of
Martha's Vineyard and Nantucket, all of which are washing away so