Page:Africa by Élisée Reclus, Volume 1.djvu/244

 wards along the foot of the main Abyssinian mountain range. At this part of its course the stream is most copious even during the dry season, being everywhere over 160 feet broad, with a depth of more than 3 feet, and a very rapid course. During the floods the Awash overflows for many miles right and left of its bed, its level rising from 40 to 46, and even to 60 feet, above the usual watermark. It might possibly be available even for steam navigation in this part of its course.

At the point where it is deflected from the mountains, the river flows north-eastwards towards Tajurah Bay, and its volume is increased by its affluent, the Germana, or Kasam, but afterwards gradually diminished, and at about 60 miles from the sea, after having traversed a distance of 480 miles, it loses itself in the marshy lake Bada, or Aussa, also called Abhelbad by many writers. This lacustrine basin, which probably lies below sea-level, rises and falls with the alternating rainy and dry seasons. Its waters are sweet, and deposit a fertilising mud, which repays a hundredfold the agricultural labour expended upon it by the Danakils of Aussa. The water necessary for the irrigation of the fields in summer is retained by a dam constructed at its northern end ; but when the lands are thoroughly watered the overflow is discharged into a basin called "Lake Natron" from the crystallised chemical substances on its banks. Other lakes belonging to the Awash system, amongst others that of Leado, commanded by the Dofaneb volcano and Jebel-Kabret or "Sulphur Mountain," not far from the Abyssinian Alps, receive the overflow of this river during the flood season. Lake Zwai, Jilalu, Laki or Dambal, in the Gurageh country, probably belongs also to the same hydrographic system, and its surplus waters are said to flow into the Awash. Nevertheless, the natives informed Antonelli and Cecchi, that this basin had no affluent; hence its Ethiopian name of Zwai, or the " Motionless."

The climate of this southern portion resembles that of the rest of Abyssinia, the only difference being that the air is more moist. The Shoa and Galla uplands, being nearer to the equator, are much more affected by the rainy zone, which lying between the two trade winds, fluctuates alternately north and south of the equator. Whilst the mean rainfall on the Abyssinian plateaux may be calculated at 30 inches annually, it is said to be about 40 inches south of the Abai and Awash. Hence the vegetation is far more dense and exuberant in the southern than in the northern regions of Abyssinia. Whilst forests are rarely met in Abyssinia outside of the kwalla districts, travellers in the mountains of Shoa and its tributary territories speak of the immense forests of conifers, wild olives, and other trees, under the matted moss-grown branches of which they have travelled for hours. The vegetable species of these countries have hitherto been studied but by few botanists; but the climate is known to be favourable to the Abyssinian flora, and many other plants flourishing here are utilised for the sake of their leaves, gums, or seeds. This home of the coffee-plant could still supply the world with many other precious shrubs; it already yields to commerce the so-called oggieh, or korarima, a fruit highly prized for its delicate flavour and aroma.