On the Blue Nile the forest trees alter, the most abundant being the babanus (Sudan ebony) and the silag (Anogeissus leiocarpus), while gigantic baobabs, called tebeldi in the Sudan, and tarfa (Sterculia cinerea) are numerous.
Colonel Lewis, who was at Karkoj with a small force, moved to Roseires, where he received reinforcements from Omdurman, and on the 26th of December caught Ahmed Fedils force as it was crossing the Blue Nile at Dakheila, and after a very severe fight cut it up. The dervish loss was 500 killed, while the Egyptians had 24 killed and 118 wounded.
At Khartum the Blue Nile is bridged and the railway is continued south through the Gezira to Sennar.
He steamed up the Blue Nile and the Rahad river to Ain-el-Owega, whence he struck across the desert, reaching Gedaref on the 21st of October, to find that Ahmed Fedil had gone south with his force of 5000 men towards Roseires.
In April 1908 Abd-el-Kader, a Halowin Arab and ex-dervish, rebelled in the Blue Nile province, claiming to be the prophet Issa (Jesus).
Work was the tracing of the Blue Nile from its source to its junction with the White Nile.
After receiving the Bahr-el-Ghazal from the west and the Sobat, Blue Nile and Atbara from the Abyssinian highlands (the chief gathering ground of the flood-water), it crosses the great desert and enters the Mediterranean by a vast delta.
Fathers Mendez and Lobo traversed the deserts between the coast of the Red sea and the mountains, became acquainted with Lake Tsana, and discovered the sources of the Blue Nile in 1624-1633.
Menelek, in addition, agreed not to obstruct the waters of Lake Tsana, the Blue Nile or the Sobat, so as not to interfere with the Nile irrigation question, and he also agreed to give a concession, if such should be required, for the construction of a British railway through his dominions, to connect the Sudan with Uganda.
This was observed by British officers, from the time of the preliminary operations about Kosha and at the action near Ginnis in December 1885 down to the brilliant operations in the pursuit of the Mahdists on the Blue Nile after the action of Gedaref (subsequent to the battle of Omdurman), and the fighting in Kordofan in 1899, which resulted in the death of the khalifa and his amirs.