[9] This long extent of country varies in elevation from 5570 to 8856 feet,--equal to the height of the passes of Mount Cenis or the Great St. Bernard. The table-land stretches still three hundred leagues farther, before it declines to a level of 2624 feet. Humboldt, Essai politique, tom. i. pp. 157, 255.{*} {*}[“The Continental range of Humboldt does not exist. The Andean system ends in northern Colombia. The Rocky Mountain system ends in the plateau south of the City of Mexico. The system between lies across the trend of the other two systems and differs from them in origin. It belongs to the same chain which crops up in the Antilles, i.e., to the system appearing in Martinique and Santa Lucia.”--Robert T. Hill, of U. S. Geological Survey, in Century Magazine, July, 1902.--M.] [10] About 62° Fahrenheit, or 17° Réaumur. (Humboldt, Essai politique, tom. i. p. 273.) The more elevated plateaus of the table-land, as the Valley of Toluca, about 8500 feet above the sea, have a stern climate, in which the thermometer, during a great part of the day, rarely rises beyond 45° F. Idem (loc. cit.), and Malte-Brun (Universal Geography, Eng. trans., book 83), who is, indeed, in this part of his work, but an echo of the former writer. [11] The elevation of the Castiles, according to the authority repeatedly cited, is about 350 toises, or 2100 feet above the ocean. (Humboldt’s Dissertation, apud Laborde, Itinéraire descriptif de l’Espagne (Paris, 1827), tom. i. p. 5.) It is rare to find plains in Europe of so great a height. [12] Archbishop Lorenzana estimates the circuit of the Valley at ninety leagues, correcting at the same time the statement of Cortés, which puts it at seventy, very near the truth, as appears from the result of M. de Humboldt’s measurement, cited in the text. Its length is about eighteen leagues, by twelve and a half in breadth. (Humboldt, Essai politique, tom. ii. p. 29.--Lorenzana, Hist. de Nueva-España, p. 101.) Humboldt’s map of the Valley of Mexico forms the third in his “Atlas géographique et physique,” and, like all the others in the collection, will be found of inestimable value to the traveller, the geologist, and the historian. [13] Humboldt, Essai politique, tom. ii. pp. 29, 44-49.--Malte-Brun, book 85. This latter geographer assigns only 6700 feet for the level of the Valley, contradicting himself (comp. book 83), or rather Humboldt, to whose pages he helps himself _plenis manibus_, somewhat too liberally, indeed, for the scanty references at the bottom of his page.