We rested above an hour in the cool shade, while our horses refreshed
themselves on the "grama" that grew luxuriantly around. We conversed
about the singular region in which we were travelling; singular in its
geography, its geology, its botany, and its history; singular in all
respects.
I am a traveller, as I might say, by profession. I felt an interest in
learning something of the wild countries that stretched for hundreds of
miles around us; and I knew there was no man living so capable of being
my informant as he with whom I then conversed.
My journey down the river had made me but little acquainted with its
features. At that time, as I have already related, there was fever upon
me; and my memory of objects was as though I had encountered them in
some distorted dream.
My brain was now clear; and the scenes through which we were passing--
here soft and south-like, there wild, barren, and picturesque--forcibly
impressed my imagination.
The knowledge, too, that parts of this region had once been inhabited by
the followers of Cortez, as many a ruin testified; that it had been
surrendered back to its ancient and savage lords, and the inference that
this surrender had been brought about by the enactment of many a tragic
scene, induced a train of romantic thought, which yearned for
gratification in an acquaintance with the realities that gave rise to
it.
Seguin was communicative. His spirits were high. His hopes were
buoyant. The prospect of again embracing his long-lost child imbued
him, as it were, with new life. He had not, he said, felt so happy for
many years.
"It is true," said he, in answer to a question I had put, "there is
little known of this whole region, beyond the boundaries of the Mexican
settlements. They who once had the opportunity of recording its
geographical features have left the task undone. They were too busy in
the search for gold; and their weak descendants, as you see, are too
busy in robbing one another to care for aught else. They know nothing
of the country beyond their own borders; and these are every day
contracting upon them. All they know of it is the fact that thence come
their enemies, whom they dread, as children do ghosts or wolves."
"We are now," continued Seguin, "near the centre of the continent, in
the very heart of the American Sahara."
"But," said I, interrupting him, "we cannot be more than a day's ride
south of New Mexico. That is not a desert; it is a cultivated country."
"New Mexico is an oasis, nothing more. The desert is around it for
hundreds of miles; nay, in some directions you may travel a thousand
miles from the Del Norte without seeing one fertile spot. New Mexico is
an oasis which owes its existence to the irrigating waters of the Del
Norte. It is the only settlement of white men from the frontiers of the
Mississippi to the shores of the Pacific in California. You approached
it by a desert, did you not?"
"Yes; as we ascended from the Mississippi towards the Rocky Mountains
the country became gradually more sterile. For the last three hundred
miles or so we could scarcely find grass or water for the sustenance of
our animals. But is it thus north and south of the route we travelled?"
"North and south for more than a thousand miles, from the plains of
Texas to the lakes of Canada, along the whole base of the Rocky
Mountains, and half-way to the settlements on the Mississippi, it is a
treeless, herbless land."
"To the west of the mountains?"
"Fifteen hundred miles of desert; that is its length, by at least half
as many miles of breadth. The country to the west is of a different
character. It is more broken in its outlines, more mountainous, and if
possible more sterile in its aspect. The volcanic fires have been more
active there; and though that may have been thousands of years ago, the
igneous rocks in many places look as if freshly upheaved. No
vegetation, no climatic action has sensibly changed the hues of the lava
and scoriae that in some places cover the plains for miles. I say no
climatic action, for there is but little of that in this central
region."
"I do not understand you."
"What I mean is, that there is but little atmospheric change. It is but
one uniform drought; it is seldom tempestuous or rainy. I know some
districts where a drop of rain has not fallen for years."
"And can you account for that phenomenon?"
"I have my theory. It may not satisfy the learned meteorologist, but I
will offer it to you."
I listened with attention, for I knew that my companion was a man of
science, as of experience and observation, and subjects of the character
of those about which we conversed had always possessed great interest
for me. He continued--
"There can be no rain without vapour in the air. There can be no vapour
in the air without water on the earth below to produce it. Here there
is no great body of water.
"Nor can there be. The whole region of the desert is upheaved--an
elevated table-land. We are now nearly six thousand feet above sea
level. Hence its springs are few; and by hydraulic law must be fed by
its own waters, or those of some region still more elevated, which does
not exist on the continent.
"Could I create vast seas in this region, walled in by the lofty
mountains that traverse it--and such seas existed coeval with its
formation; could I create those seas without giving them an outlet, not
even allowing the smallest rill to drain them, in process of time they
would empty themselves into the ocean, and leave everything as it now
is, a desert."
"But how? by evaporation?"
"On the contrary, the absence of evaporation would be the cause of their
drainage. I believe it has been so already."
"I cannot understand that."
"It is simply thus: this region possesses, as we have said, great
elevation; consequently a cool atmosphere, and a much less evaporating
power than that which draws up the water of the ocean. Now, there would
be an interchange of vapour between the ocean and these elevated seas,
by means of winds and currents; for it is only by that means that any
water can reach this interior plateau. That interchange would result in
favour of the inland seas, by reason of their less evaporation, as well
as from other causes. We have not time, or I could demonstrate such a
result. I beg you will admit it, then, and reason it out at your
leisure."
"I perceive the truth; I perceive it at once."
"What follows, then? These seas would gradually fill up to overflowing.
The first little rivulet that trickled forth from their lipping fulness
would be the signal of their destruction. It would cut its channel over
the ridge of the lofty mountain, tiny at first, but deepening and
widening with each successive shower, until, after many years--ages,
centuries, cycles perhaps--a great gap such as this," (here Seguin
pointed to the canon), "and the dry plain behind it, would alone exist
to puzzle the geologist."
"And you think that the plains lying among the Andes and the Rocky
Mountains are the dry beds of seas?"
"I doubt it not; seas formed after the upheaval of the ridges that
barred them in, formed by rains from the ocean, at first shallow, then
deepening, until they had risen to the level of their mountain barriers;
and, as I have described, cut their way back again to the ocean."
"But does not one of these seas still exist?"
"The Great Salt Lake? It does. It lies north-west of us. Not only
one, but a system of lakes, springs, and rivers, both salt and fresh;
and these have no outlet to the ocean. They are barred in by highlands
and mountains, of themselves forming a complete geographical system."
"Does not that destroy your theory?"
"No. The basin in which this phenomenon exists is on a lower level than
most of the desert plateaux. Its evaporating power is equal to the
influx of its own rivers, and consequently neutralises their effect;
that is to say, in its exchange of vapour with the ocean, it gives as
much as it receives. This arises, not so much from its low elevation as
from the peculiar dip of the mountains that guide the waters into its
bosom. Place it in a colder position, _ceteris paribus_, and in time it
would cut the canal for its own drainage. So with the Caspian Sea, the
Aral, and the Dead Sea. No, my friend, the existence of the Salt Lake
supports my theory. Around its shores lies a fertile country, fertile
from the quick returns of its own waters moistening it with rain. It
exists only to a limited extent, and cannot influence the whole region
of the desert, which lies parched and sterile, on account of its great
distance from the ocean."
"But does not the vapour rising from the ocean float over the desert?"
"It does, as I have said, to some extent, else there would be no rain
here. Sometimes by extraordinary causes, such as high winds, it is
carried into the heart of the continent in large masses. Then we have
storms, and fearful ones too. But, generally, it is only the skirt of a
cloud, so to speak, that reaches thus far; and that, combined with the
proper evaporation of the region itself, that is, from its own springs
and rivers, yields all the rain that falls upon it. Great bodies of
vapour, rising from the Pacific and drifting eastward, first impinge
upon the coast range, and there deposit their waters; or perhaps they
are more highly-heated, and soaring above the tops of these mountains,
travel farther. They will be intercepted a hundred miles farther on by
the loftier ridges of the Sierra Nevada, and carried back, as it were,
captive, to the ocean by the streams of the Sacramento and San Joaquim.
It is only the skirt of these clouds, as I have termed it, that, soaring
still higher, and escaping the attractive influence of the Nevada,
floats on, and falls into the desert region. What then? No sooner has
it fallen than it hurries back to the sea by the Gila and Colorado, to
rise again and fertilise the slopes of the Nevada; while the fragment of
some other cloud drifts its scanty supply over the arid uplands of the
interior, to be spent in rain or snow upon the peaks of the Rocky
Mountains. Hence the source of the rivers running east and west, and
hence the oases, such as the parks that lie among these mountains.
Hence the fertile valleys upon the Del Norte, and other streams that
thinly meander through this central land.
"Vapour-clouds from the Atlantic undergo a similar detention in crossing
the Alleghany range; or, cooling, after having circled a great distance
round the globe, descend into the valleys of the Ohio and Mississippi.
From all sides of this great continent, as you approach its centre,
fertility declines, and only from the want of water. The soil in many
places where there is scarcely a blade of grass to be seen, possesses
all the elements of vegetation. So the doctor will tell you; he has
analysed it."
"Ya, ya! dat ish true," quietly affirmed the doctor.
"There are many oases," continued Seguin; "and where water can be used
to irrigate the soil, luxuriant vegetation is the consequence. You have
observed this, no doubt, in travelling down the river; and such was the
case in the old Spanish settlements on the Gila."
"But why were these abandoned?" I inquired, never having heard any
reason assigned for the desertion of these once flourishing colonies.
"Why!" echoed Seguin, with a peculiar energy; "why! Unless some other
race than the Iberian take possession of these lands, the Apache, the
Navajo, and the Comanche, the conquered of Cortez and his conquerors,
will yet drive the descendants of those very conquerors from the soil of
Mexico. Look at Sonora and Chihuahua, half-depopulated! Look at New
Mexico; its citizens living by suffrance: living, as it were, to till
the land and feed the flocks for the support of their own enemies, who
levy their blackmail by the year! But, come; the sun tells us we must
on. Come!
"Mount! we can go through," continued he. "There has been no rain
lately, and the water is low, otherwise we should have fifteen miles of
a ride over the mountain yonder. Keep close to the rocks! Follow me!"
And with this admonition he entered the canon, followed by myself, Gode,
and the doctor.