Fig. 16. Mexico and Central America
Orizaba is situated in the north central part of Mexico, about seventy-five miles west of Vera Cruz. Its ancient Aztec name was Cittaltepetl, or Star Mountain. The height of the mountain is 18,200 feet. Like all high tropical mountains whose summits are snow-clad, one would pass through the same changes in climate, in going from its base to its summit, as in going along the earth's surface from the equator to the poles. Near the base of the mountain will be found a tropical climate, above that a temperate climate, while in still higher regions, the climate of the Arctic region.
According to Russell, from whose work on the volcanoes of North America much of the information concerning the volcanoes of Mexico and Central America has been condensed, Orizaba has three craters on its summit. The last recorded eruption took place about the middle of the Eighteenth Century. The mountain is now in a dormant or extinct condition, as may be seen from the fact that its three craters are for the greater part filled with snow.
Orizaba, like Etna, and many other volcanoes, has deep fissures extending through its sides. Through these, lava streams have flowed during times when it was active. There are also found on the slopes of this mountain many cones of a type known as parasitic cones. These cones are not caused by materials that have been brought to the surface during an eruption, but have been formed by the steam passing through lava streams that have come out of the crater during other eruptions.
Popocatepetl, or, as the word means, The Smoking Mountain, is the second highest mountain in Mexico. According to recent measurements made by the Mexican Government, its height is 17,876 feet. Popocatepetl is situated on the edge of the great plateau of Mexico, forty miles southeast of the City of Mexico. It is a conical mountain, and is a magnificent object when seen from the City of Mexico, rising, as it does, fully 10,000 feet from the elevation of the city, while on the east it towers for nearly 18,000 feet above the level of the sea. This splendid mountain is poetically described by Russell:
"Seen from the basal plains, it sweeps up in one grand curve to nearly its full height,—a collossus of three and a quarter miles in elevation, white with everlasting frost on its summit, and bathed in the green of palms, bananas, oranges, and mangoes, at its base. Evergreen oaks and pines encircle its middle height, and above them, before the ice itself is reached, occur broad areas of loose sand into which the lavas have been changed by weathering. Soft wreaths of sulphurous vapor may at times be seen curling over the crest of the summit crater,—gentle reminders that the days of volcanic activity are not yet necessarily over."
Popocatepetl takes its name, The Smoking Mountain from the fact that gases and vapor are continually being emitted from its summit crater. It has a conical peak with a depression or crater on its summit. The bottom of the crater is crossed by fissures from which small quantities of steam escape, not, however, sufficient to melt all the snow which covers the slopes of the mountain to a depth of from eight to ten feet. A small lake of hot water has collected in the crater from the water derived from the melting snow. This water, sinking through the porous materials in the cone, is the source of a great number of large hot springs that occur around the base of the mountain.
Reclus states that the first to climb to the top of Popocatepetl was one of Cortez' officers, 1519.
Another snow-capped volcano, which rising from the plain of Mexico is in clear view of the city, is Ixtaccihuatl (Ets-tak'-se-wat-el), or as the word means in the ancient Aztec, The White Woman. This mountain, as measured by Heilprin, is 16,960 feet in height. Ixtaccihuatl is now in so dormant a condition that many who have climbed to the top assert that it is not a volcano at all, since they find no crater on its summit. Nor are there any signs of volcanic heat, the summit being snow clad during summer. The conical form of the mountain, however, and the fact that the entire mountain is formed of volcanic rocks, show beyond doubt that it is an extinct volcano, whose crater has most probably been completely filled in by the washing away of its sides.
Xinantecatl is another extinct volcanic mountain situated about forty miles southwest of the City of Mexico. It is about 16,500 feet high. Its name means in the ancient Aztec language, The Naked Lord. It is also sometimes known as the Nevado de Toluca, or The Snow of Toluca. On the top of the peak are two craters filled with lakes of fresh water. Russell states that the larger of these lakes is about thirty feet in depth and contain a peculiar species of fish.