Chapter 18 - The Scalp Hunters by Mayne Reid
Geography and Geology
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 cañon), “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 cañon, followed by myself, Gode, and the doctor.