elevation, and here we accordingly find its highest
mountains, the Alps. In another part of this continent, we see the
Dwina, the Nieper, and the Volga, diverge from points not far distant
from each other, and here accordingly we find an elevated table land,
two hundred miles in length by fifty in breadth, marked however by no
mountain summits. In central Asia, we see a vast space inclosed by lines
joining the sources of a number of mighty rivers, the Indus, the Ganges,
the Barrampooter, the Irrawaddy, the Houng Ha, and Kiang Ku, the Amour,
the Lena, the Yermisir, and the Oby; accordingly, here we find the
greatest table land surrounded by the highest mountains of the globe.
Still, however, the instance we have cited of the rivers of Russia
shows, that the land whence great rivers take their rise, is not
necessarily mountainous; in this case the ascent is almost
imperceptible, and the summit offers the aspect of a level and marshy
plain. Such also occurs in the famous boundary between the United
States and Canada, where the highlands that figured in two successive
treaties have disappeared, and in their supposed place has been found a
series of swamps.

Attempts have been made to arrange the chains of mountains into
connected systems. Of these the most successful is that of Malte-Brun.

"If we draw a line from the centre of Thibet, across Chinese
Mongolia towards Ochotsk, and thence towards Cape Tchutscki,
the eastern promontory of Asia, this line will in general
coincide with a great chain of mountains which runs from the
south-west to the north-east, and which every where descends
rapidly towards the Indian and Pacific oceans, while on the
contrary, it extends itself towards the Frozen ocean in high
plains and secondary hills. It is probable that we may some day
refer to the same rule the chain of Lapata, called the backbone
of the world, in Africa; at any rate this chain runs from the
Cape of Good Hope to that of Gardafui, in a direction
south-east and north-west, and therefore in nearly the same
direction as the great chain of Asia, but we are ignorant of
the disposition of the slopes of these mountains. We may regard
the mountains of the Happy Arabia, which are both steep and
lofty, as the link that connects the mountains of Lapata with
the table lands and mountains of Persia, which proceed from the
mountains of Thibet.