The former
of these systems, partly covered by the ocean, may be compared, with
respect to its relative position and form, to the Sierra Parime; the
latter, to the Brazil chains, running also from south-west to
north-east. The culminant points of those two systems rise to 1138 and
1040 toises. Such are the elements of this curve, of which the convex
summit is in the littoral chain of Venezuela:
AMERICA, EAST OF THE ANDES.
COLUMN 1 : SYSTEMS OF MOUNTAINS.
COLUMN 2 : MAXIMA OF HEIGHTS IN TOISES.
Brazil Group : Itacolumi 900 (south latitude 20 1/2 degrees).
Parime Group : Duida 1300 (north latitude 3 1/4 degrees).
Littoral Chain of Venezuela : Silla of Caracas 1350 (north latitude 10
1/2 degrees).
Group of the West Indies : Blue Mountains 1138 (north latitude 18 1/5
degrees).
Chain of the Alleghenies : Mount Washington 1040 (north latitude 44
1/4 degrees).
I have preferred indicating in this table the culminant points of each
system to the mean height of the line of elevation; the culminant
points are the results of direct measures, while the mean height is an
abstract idea somewhat vague, particularly when there is only one
group of mountains, as in Brazil, Parime and the West Indies, and not
a continued chain. Although it cannot be doubted that, among the five
systems of mountains on the east of the Andes, of which one only
belongs to the southern hemisphere, the littoral chain of Venezuela is
the most elevated (having a culminant point of 1350 toises, and a mean
height from the line of elevation of 750), we yet recognise with
surprise that the mountains of eastern America (whether continental or
insular) differ very inconsiderably in their height above the level of
the sea. The 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 uniformity 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.* (* Not even the
White Mountains of the state of New Hampshire, to which Mount
Washington belongs. Long before the accurate measurement 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.) It may be added that,
with the exception of the Alleghenies, no snow falls sporadically in
any of the eastern systems which we have just examined.
