352 UNIFORMITY OF CONFIGURATION. 



five groups are all nearly of an average height of from 500 

 to 700 toises ; and the culminant points (maxima of the 

 lines of elevation) from 1000 to 1300 toises. That uni- 

 formity of structure, in an extent twice as great as Europe, 

 appears to me a very remarkable phenomenon. No summit 

 east of the Andes of Peru, Mexico, and Upper Louisiana, 

 rises beyond the limit of perpetual snow.* It may be 

 added, that with the exception of the Alleghanies, no snow 

 falls sporadically in any of the eastern systems which we 

 have just examined. Prom these considerations it results, 

 and above all, from the comparison of the New Continent 

 with those parts of the old world which we know best, with 

 Europe and Asia, that America, thrown into the aquatic 

 hemispheref of our planet, is still more remarkable for the 

 continuity and extent of the depressions of its surface, than 

 for the height and continuity of its longitudinal ridge. 

 Beyond and within the isthmus of Panama, but eastward 

 of the Cordillera of the Andes, the mountains scarcely 

 attain, over an extent of 600,000 square leagues, the height 

 of the Scandinavian Alps, the Carpathians, the Monts-Dores 

 (in Auvergne), and the Jura. One system only, that of the 



* Not even the White Mountains of the state of New Hampshire, to 

 which Mount Washington belongs. Long before the accurate measure- 

 ment of Captain Partridge, I had proved (in 1804), by the laws of the 

 decrement of heat, that no summit of the White Mountains could 

 attain the height assigned to them by Mr. Cutler, of 1600 toises. 



f- The southern hemisphere, owing to the unequal distribution of seas 

 and continents, has long been marked as eminently aquatic ; but the same 

 inequality is found when we consider the globe as divided not according to 

 the equator but by meridians. The great masses of land are stinted 

 between the meridian of 10 west, and 150 east of Paris, while the hemis- 

 phere eminently aquatic begins westward of the meridian of the coast of 

 Greenland, and ends on the east of the meridian of the eastern coast of 

 New Holland and the Kurile Isles. This unequal distribution of land 

 and water has the greatest influence on the distribution of heat over the 

 surface of the globe, on the inflexions of the isothermal lines, and the 

 climateric phenomena in general. For the inhabitants of the central parts 

 of Europe the aquatic hemisphere may be called western, and the land 

 hemisphere eastern ; because in going to the west we reach the former 

 sooner than the latter. It is the division according to the meridians, 

 which is intended in the text. Till the end of the 15th century, the 

 western hemisphere was as much unknown to the nations of the eastern 

 hemisphere, as one half of the lunar globe is to u at present, and will 

 probably always remain. 



