Page:The American Cyclopædia (1879) Volume I.djvu/64

 ABYSSINIA cipices with a turbulence well denoted by its name. Further S. is the Abai, the celebrated Nile of Bruce, although the Bahr-el-Azrek or true Blue river rises in the Galla country under the name of the Dedhesa, and the Abai is in reality only its largest tributary. The latter rises S. of the Tzana lake, and making a north- ward circle through it, turns southward and joins the Bahr-el-Azrek near lat. 11 N. This lake, also called the Dembea, is situated in a grain-producing region of great fertility, at a height of 6,110 ft. above the level of the sea. It is about 50 m. long by 25 m. wide, and its depth in some places is said to be 600 ft. There are many other lakes, among which Ashangi, 4 m. long and 3 m. broad, in the country of the Azebo-Gallas, is the most noteworthy as being a fresh-water lake without any visible outlet. Thermal springs occur in many districts. The characteristic feature of the climate of the Abyssinian highlands including Tigre", Am- hara, and Shoa is the occurrence of a tropical monsoon or rainy season from the middle of June to the end of September. Otherwise, the climate is strictly temperate. There is a cold season extending from October to February, with an estimated mean temperature of 58-3, during which the days are pleasant and the nights cold with heavy falls of dew. The hot weather begins about March 1, and lasts until the monsoon sets in, April being the wannest month. The mean temperature of this season at Magdala is 65'5, and of the wet season about 5 lower. The rainfall of the monsoon extends over all of Abyssinia proper, but ia greater in the south and west than in the north and east. The prevailing winds during the rainy season are easterly and southeasterly. Thunder storms are of frequent occurrence. The chief agricultural productions are barley and oats on the elevated plains, and wheat, maize, millet, rice, cotton, coffee, and a small native grain called teff, in the lower districts. Sugar cane, flax, and beans are raised in small quantities, and lemons, oranges, and figs are oc- casionally produced. The grape thrives in some parts of Tigr6, but no good wine is made. Volcanic rocks constitute the principal for- mation in the geological structure of Abys- sinia, and cover almost the entire table land. The trappean series appears to be divisible into at least two distinct groups. The lower of these is largely composed of red basalts, on which the disintegrating effects of atmospheric action are plainly marked. Blanford names this the Ashangi group, and that above it the Magdala group ; which last comprises trachytic rocks containing many feldspar crystals, and is distinguished by the scarped and precipitous forms which it assumes under the influence of the weather. These forms are characteristic of Abyssinian scenery, and the ambas or hill forts, the great strongholds of the country, are rendered almost inaccessible to an enemy by their situation on the horizontal beds of this rock which surmount the summits usually se- lected for military stations. In the N. E. prov- inces, however, metamorphic rocks occupy the whole surface, except in several districts of Hill Fort between Mai and Abaca. limited extent where they are overlaid by sand> stones, limestones, or igneous formations. They extend 150 m. along the meridian of 89 30', between lat. 15 55' and 13 50' N. At Tchelga coal deposits are found, which geologists are disposed to group with these sandstones of Adigerat. Further S., in the Antalo district, a considerable number of fossils have been ob- tained from the limestones which predominate there, whereby it has been ascertained that the formation belongs to the oolitic period. The present geological aspect of Abyssinia, with its weather-worn battlements of rock and its deeply scored river beds, must be attributed to fresh-water denudation. There is no evidence of marine action anywhere in the interior, although it is believed that at an early epoch the waters of the Red sea and the Indian ocean may have washed the foot hills of the eastern slope. The volcanic formations along the coast belong to an age much more recent than that which gave rise to those of the table land which have already been described. There are no volcanoes in the country. The only metallic products are gold, which occurs rarely and is of an inferior quality, and iron, of which the yield is consumed at home. Exten- sive deposits of salt occur on several plains in Tigre. The distribution of Abyssinian animals seems to be regulated by the altitude, of the