the two great equatorial lakes effected their junction at a point some two hundred and fifty miles north of the western lake source (Lake Albert); for he surmises that this lake lies approximately under the sixth degree of south latitude (its southernmost extremity is in 1° 10′ north of the equator). His hypothetical Lake Victoria lies under or extends to the seventh degree of south latitude, instead of no farther than about 3° 30′ south. Ptolemy, however, was careful to discriminate between the lake sources of the White Nile and the lake (Tsana) from which the Blue Nile issues in the highlands of Abyssinia. This sheet of water he calls definitely Coloe, and states that it is the source of the river Astapus (or Blue Nile). It is thought that Strabo also made allusion to Lake Tsana under the name of Psebo. It is probable that both Strabo and Ptolemy heard of this lake source of the Astapus or Blue Nile from Greek traders who had penetrated Abyssinia; for, during the first centuries after Christ, Axum (then called Auxuma) had become an important trading-centre which was reached from Adulis (Adulis being a port on the Red Sea not far from the modern Masawa). Ptolemy’s location of Lake Tsana, however, like the equatorial lakes, is too far to the south. His sketch of the main course of the Atbara (Astaboras) on the one hand, and of the Blue Nile (Astapus) on the other, would not be very incorrect, but for the fact that he makes these streams unite somewhere in the latitude of Khartum and then separate again, their northern separation enclosing the island of Meroe. The Græcicised names of Astapos (Blue Nile) and Astaboras (Atbara) were recorded before the days of Ptolemy by Eratosthenes, but were not applied in the same definite way to the Blue Nile and the Atbara. Eratosthenes sometimes applies the name of Astapos to the main stream of the Nile and not specially to the Blue Nile. He also mentions that the main stream of the Nile is called Astasobas. It is evident that in these words we have corruptions of local names, possibly derived from Nubian, or it may be from Hamitic languages. Astaboras needs but little identification with the Atbara. Astapus (Greek = Astapos) is not clearly recognizable under the modern Abyssinian name of the Blue Nile,--Abai. The second part of Astasobas certainly recalls the name Sobat, which besides being applied by the Sudanese Arabs to the Baro or Sobat is also sometimes given by them or by the Nile Negroes to the main course of the White Nile south of Khartum. Asta may have been some Ethiopian term meaning “river.”