It is bounded by New Mexico on the east, by Mexico on the south, by Utah and Nevada on the north and north-west, and by California in continuation of the western boundary. It is as large as New York, Pennsylvania, Maryland, New Jersey, and Delaware together. Whom it belonged to first, so far as occupation constitutes possession, I know not; but the Spaniards owned and neglected it for more than three centuries before the Americans possessed it. In 1848 and 1853 the regions now forming Arizona, New Mexico, Colorado, Utah, and Nevada were ceded by the descendants of the Spanish conquerors to the conquering Anglo-American. It would need weeks of assiduous travel to explore the portion of Arizona where the most interesting ruins in America, the cities of the Zoltecs or the Aztecs--for the experts differ respecting their origin--are to be found. The weight of authority and of recent investigation leads one to believe that the Aztecs were not the builders of these ruined cities. Humboldt, indeed, believed that they were; but, as Mr. Hinton remarks, in his capital little handbook, which I recommend to prospectors, emigrants, tourists, and travellers, "to suppose such an utter abandonment of settled habitations, it will be necessary to suppose some strange impelling reasons, either in climate or other causes, that must have amounted to a catastrophe. An hypothesis which would leave a whole race able to conquer an empire, and to preserve power enough to abandon without destruction their old homes, implies conditions and forces without a known historical parallel." The conclusion that many native cities were flourishing when the Spaniards arrived in America may, perhaps, be questioned. There is a distinctive character about them, differing from that of the Mississippi mounds, the Central American pyramids, or the ruined cities of Yucatan. The site of one of these cities was pointed out to us from the train, and that was all we saw of them. But I heard so much about the mysterious remains that I was induced to procure Mr. Bancroft's remarkable essay on the native races of the Pacific Coast. Mr. Bancroft believes that the Pueblos and other Indians, in a state of civilisation which they subsequently lost, were the earliest inhabitants of these countries and the builders of the cities; that the Apaches came down upon them, and their work being then aided by the Spaniards, this original agricultural people were swept off the face of the earth. But where the Apaches came from the American ethnologists have not, I believe, determined. For hundreds of miles these ruins cover the country--stone houses, ancient watch-towers, and adobe buildings, around which are quantities of stone implements, masses of crockery and pottery. In some places there are structures of wood and stone, without iron, the masonry consisting of thin plates of sandstone dressed on the edges, and laid in coarse mortar nearly as hard as the stone itself.