the "Valley of Mexico," is nearly one thousand square miles in extent and from five thousand to eight thousand feet above the level of the sea. Three hundred years ago one-tenth part of this plateau was covered with lakes, both salt and fresh. These have dwindled in size since those early days, probably because the surrounding hills have been stripped by the invaders almost bare of the luxuriant forests which once covered them. Lofty hills form a rampart on three sides of this table-land. On the north it opens out on a great natural road leading along the level mountain-tops for a distance of twelve hundred miles. It was probably along this great highway that many of the early settlers of Mexico came from their homes at the North.
Rising out of this vast mountain-mass are snow-capped peaks, one of which—the highest land on our continent—is a mile and a half higher than the lofty platform on which it stands. Along the nineteenth parallel of latitude rise five volcanoes. Two of these overlooked the Aztec capital and bore the Indian names they still hold. Popocatapetl—"the hill that smokes"—has been doing its best to deserve that title ever since it received it; Iztaccihuatl—"the woman in white"—is so called from its fancied resemblance to the form of a woman lying with her face upturned to the sky, a snowy robe folded across her breast.
Descending on each side from this rocky platform to the sea, the traveler passes over three great natural terraces, each of which has a different climate and productions differing with the elevation. In the Aztec country, which lay entirely within the tropics, the whole scale of vegetation could be found. Forests of evergreen oaks and pine flourished on the mountains, below the snow
