MOUNTAINS, RIVERS, LAKES. 3 



These are, as given by the Mexican geographer, Cubas : Popocatapetl, 5,400 metres; 

 Orizaba, 5,295; Iztaccihuatl, 4,775; Nevada de Toluca, 4,440; Cofre de Perote, 

 4,089; Zempoaltepetl, 3,668; Ajusco, 3,575; Volcan de Colima, 3,396, and Quinceo, 

 3,324 metres. " The most interesting feature of the distribution of volcanoes," says 

 a learned writer, " is that nearly all are situated along the mountain-chains and rows 

 of islands which border the shores of the continent, while the interior of these great 

 land masses is nearly free from them." This seems to be exceptional in Mexico, 

 as the highest and most noted volcanoes, as Popocatapetl, Nevada de Toluca, 

 Cofre de Perote and Jorullo, are in the centre of the table-land, and traverse the 

 country in a line from west to east. All the Mexican volcanoes are either extinct or 

 quiescent; none have been in eruption in the present century, though smoke has 

 been seen issuing from the crater of Popocatapetl. 



The Mexican river system, owing to the rugged configuration of the surface, is 

 neither varied nor extensive. Most of the rivers are short, and little more than 

 impetuous torrents or sluggish bayous, without navigable depth of water. The 

 steep mountain-slopes are quickly drained, and the great plateaux rapidly absorb 

 the waters that fall into them, owing to their aridity. The surface of the table-land 

 is cut up into innumerable barrancas and ravines, some of profound depth, caused 

 by the plunging torrents, speeding on their way to the sea. Since the comprehen- 

 sive railway system of Mexico has been projected, the canalization of Mexico will 

 not be needed, nor will the almost total lack of navigable waters be sorely felt. 

 Even the longest streams (such as the Rio Grande, which forms the boundary line 

 between Mexico and Texas, and is about 1,500 miles in length), are navigable for 

 but a short distance. There are some twenty rivers above one hundred miles long, 

 the principal of which are : the Rio Grande, the Santiago, 500 miles ; the Balsas, 400 ; 

 Yaquis, 375; Grijalva, or Tabasco, 330; Usumacinta, 320; Conchos, 300; Mezqintal, 

 310; Panuco, 275; Altar, 260; Nazas, 260; Sinaloa, 250; Fucrte, 240; Mayo, 200; 

 Ures, 200; Alvarado, 150; Culiacan, 150; and Goatzcoalcos, 140 miles. 



The number of lakes in Mexico is very small, and may be counted upon one's 

 fingers. Leaving out the lagunas, which are merely bodies of salt water separated 

 from the Gulf by sand-banks and shoals, we find not more than ten inland lakes. 

 These are, the five lakes and ponds of the Valley of Mexico: Tezcoco, Chalco, 

 Xochimilco, Xaltocan, and Zumpanzo ; Chapala, the largest in Mexico, having an 

 estimated area of 1,300 square miles, situated in Jalisco; two or three small bodies 

 m the laguna country, in Chihuahua and southwest Coahuila. The lacustrine 

 basins, though of sufficient area, are so arid and so exposed to the influences of a 

 hot climate, at a great altitude, that evaporation is rapid, and causes the total disap- 

 pearance of many streams and even^kes. 



CLIMATE AND SEASONS. 



So intimately connected are climate and vegetation, that to indicate the variations 

 of the one is to suggest a corresponding change in the flora of the country. 



Were Mexico nearly level from gulf to ocean, it would have mainly a tropical 

 climate, as it lies to a great extent south of the northern tropic; but, owing to physi- 

 cal causes, a large area of its territory enjoys the climate of the temperate zone. 

 Rising by successive stages to a height of nearly 18,000 feet, the temperature, of 

 course, undergoes a diminution corresponding with the elevation above the sea. 



