The Abyssinian branch of the Nile, known as the Bahr-el-Azrek, or Blue River, rises under the name of the Dedhesa in the Galla country, south of Abyssinia, about 73 miles west of Sokka, the capital of Enarea. It springs from a swampy meadow in the same elevated plains where the Godjeb and other affluents of the White Nile originate, and after a completely spiral course, in which it separates the kingdoms of Guma and Enarea, it maintains a general north-westerly direction till it joins the White Nile at Khartum. Of the many tributaries to the Blue River, the Abái, the Nile of Bruce, is the greatest and most celebrated. Its sources are in a swampy meadow near Mount Giesk, in the district of Sákkata, from whence it takes a circular direction round the peninsula of Gojam, passing through Lake Dembea, and receiving many affluents from the mountain-chain that forms the cone of the peninsula, and at last falls into the Dedhesa or Bahr-el-Azrek, in about 11° N. latitude. From that point no stream of any consequence joins either the Blue River, or the united streams of the Blue and White Rivers, till 160 miles below their confluence, where the Atbarah, or Takkazie, falls into it. This river, which is the principal tributary of the Nile, is formed by two branches. The Takkazie rises in the mountains of Lasta, near Lalíbata, one of the most celebrated places in Abyssinia, remarkable for its churches hewn out of the living rock, and the Tselari, which springs from Mount Biála, the northern extremity of the high land of Lasta, which divides the head waters of the two branches. The united stream, after winding like the other rivers of this country, joins the Nile in 18° N. latitude, the northern limit of the tropical rains. The Abyssinian rivers in the early part of their course are little more than muddy brooks in the dry season, but during the rains they inundate the plains. They break from the table-lands through fissures in the rocky surface, which are at first only a few yards wide, but gradually increase to several miles; the streams form cataracts from 80 to more than 100 feet high, and then continue to descend by a succession of falls and rapids, which decrease in height as they go northwards to join the main stream. The Takkazie takes its name of “The Terrible” from the impetuosity with which it rushes through the chasms and over the precipices of the mountains. A peculiarity of most of the principal affluents of the Nile is their spiral course, so that, after having formed a curve of greater or less extent, generally round insulated mountain masses, they return upon themselves at a short distance from their sources. It is by no means improbable that the head stream of the Nile itself takes a spiral course round a lofty mountain mass, similar to the snow-clad mountains of Sámien and Káffa.[119]