From its quitting Copiapo, the most northerly province of Chili, till it arrives opposite to the great island of Chiloe and the archipelago of Guaytecas, is the space in which the Cordillera is conjectured to attain an elevation superior to that of the equatorial ridges of Popayan and Quito; as in this space are the lofty peaks of the Descabezado, the Tupungato, Blanquillo, Manflos, Longavi, Chillan, and the Corcobado or Gibbous mountain; all of which rise so far superior to the lower limits of perpetual congelation, that not only Molina, but other travellers have imagined they must be higher than the equinoctial range, though unfortunately all those who have had the opportunity of seeing them, have either been ignorant of the methods of determining their altitudes, or have been engaged in such active employments as to have precluded them from making any other than slight and general observations.
One of the most curious circumstances attendant on the scenery of the Cordillera of the Andes, and which is, from local causes, in a great measure peculiar to those mountains, is the extreme regularity with which the inferior term of congelation or lower limit of perpetual snow, is described on their heads; this feature has therefore been introduced into the drawing, and that in such a manner as to show by the scales placed on its sides, the various heights at which the phenomenon takes place, in the different latitudes the mountains are situated in.
Some of the principal cities, towns and volcanoes, and a few of the most extraordinary scenes in the Andes, have also been introduced, and a scale of miles has been adapted to the right hand, as well as a scale of feet to the left, in order to afford every facility to the reader of the work, in forming just notions of the singular situations of those objects, which may be better done in a graphic manner, than by any description; but as the immediate object of this plate is to exhibit comparative magnitude, on a determinate scale, it is with this view only that it has been constructed, no regard having been paid to the effect as a drawing.
In the centre is introduced the Mountain island of Socorro, one of the Revillagegido group, off the western coast of New Spain, which attains a great elevation for so small a spot, and is remarkable as being nearly on the same parallel as the volcanic summits of Popocatepetl or the Smoky Mountain, Citaltepetl, or Pico de Orizaba, or the Starry Mountain; Iztaccihuatl, or the White Woman; Nauhcampatepetl, or Cofre de Perote, or the Square Mountain; the Volcan de Xorullo and the Volcan de Colima, on the continent, and as being itself evidently the produce of an ancient eruption.
Comparative Altitudes of Mountains and Towns
The ensuing list will be found to contain an enumeration of most of the works which may be referred to as the best authorities for the early and modern history, &c. of the Spanish colonies in the western world.