“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?”