Note 646 — Chapter XI · —The Anthropo-Geography Of Rivers

A river like the Nile, lower Volga, Irtysh or Indus, rising in highlands of abundant rainfall but traversing an arid or desert land, acquires added importance because it furnishes the sole means of water travel and of irrigation. The Nile has for ages constituted the main line of intercourse between the Mediterranean and Equatorial Africa. The Tigris, Euphrates, Indus, and the Niger where it makes its great northern bend into the Sahara near Timbuctoo,646 attest the value to local fertility and commerce inherent in these rivers of the deserts and steppes. Such rivers are always oasis-makers, whether on their way to the sea they periodically cover a narrow flood-plain like that of the Nile, or one ninety miles wide, like that of the Niger's inland delta above Timbuctoo;647 or whether they emerge into a silent sea of sand, like the Murghab of Russian Turkestan, which spreads itself out to water the gardens of Merv.