'The Transactions of the Bombay Geographical Society. From December 1854 to March 1856. (New Issue.) Edited by the Secretary. Volume XII.' [‎15] (34/258)

DEPRESSION OF ARAL AND THE CASPIAN.
XV
Che level of the surrounding country, and seems to be the crater of an extinct
volcano, lava being in abundance at no great distance. The water it contains
is nearly saturated with subcarbonate of soda, the Natron of the lakes of Egypt.
We now come to the consideration of the largest and most wonderful depression
in the world,—that of the north-east of Asia,—not including that of the Dead
Sea, an account of which will be given last. From the borders of the Gulf of Fin
land and the Black Sea to those of the Yellow Sea, extending all across Central
Asia, there is a space nearly 4,000 miles from east to west, and at its western ex
tremity nearly half as much from north to south, comprising in all an area of
above three millions of square miles, containing lakes and rivers numberless, but
which send not one drop of water to the ocean, evaporation subliming into the
air all the moisture that appears on the ground. In the western portion of this
the ground sinks in some places above 80 feet beneath the level of the ocean,
affording a vast space of from 760,000 to 800,000 square miles in area, or larger
than the Mediterranean, to all appearance the basin of an old inland sea, at no
time more than slightly connected with the Northern Ocean. This depression
comprehends the whole of Tr&ns-Oxonia, including the basins near its lowest part,
of the Aral and Caspian, the surface of the latter being 83 feet beneath the
Mediterranean. From his observations on these points Humboldt arrives at the
following wonderful but far from improbable conclusions:—
‘ 1. That before the times which we call historic, at epochs very near in point
of time to the latest revolutions on the surface of the globe, the lake Aral may
have been entirely comprehended in the basin of the Caspian Sea, and that then
the great depression of Asia, (the concavity of Tauran,') may have formed a vast
interior sea, which may have communicated on one side with the Euxine, and on
the other side, by means of cracks more or less wide, with the Icy Sea, and the
lakes Telegoul, Talas, and Balkhache.
‘2. That even in the historic times, we must not admit too generally that the
soil has followed the successive changes which seem to be indicated by the chro
nological series of opinions emitted by ancient historians and geographer's. These
authors seldom represent the geography of their epoch ;—they choose between
preceding opinions, and their absolute silence respecting certain facts or natural
phenomena, is no argument against the existence of these phenomena.
‘3. That very probably from the time of Herodotus, as at the epoch of
the Macedonian expedition, the Aral formed but a lateral appendage of the
Oxus, and that it communicated with the Caspian only by the arm which the
Scythian Gulf of that sea extends so far to the coast, and receives the river
Oxus.
‘ 4. That either by the simple phenomenon of the increase of growth, (the
preponderance of evaporation over aqueous supply,) or by plutonic crevices or
elevations, the Scythian gulf (the Karabogas) has been progressively contracted
in its narrowest dimensions, and that by the retreat of the gulf, the bifurcation
of the Oxus has been developed, that is, has become more and more manifest.
One portion of the waters of the Oxus has preserved its course towards the
Caspian by a river bed which modern travellers (posterior to the middle ot the