In the 5th century B.C. Herodotus visited Egypt and travelled up the Nile as far as Elephantine. On his journey, he met a priest who claimed to know where the source of the Nile was. There were apparently two mountains called Crophi and Mophi, and in the centre of each was a vast bottomless fountain. These two fountains gave rise to the Nile. Herodotus was sceptical. Ptolemy (A.D. 90 - A.D. 168)elaborated upon this story, and located the fountains in a range of mountains south of the equator, which he named "TheMountains of the Moon". Why he chose this name is not known for certain. Arab explorers in the dark ages spoke of the Mountains of Gumr. Gumr was believed to be a corruption of Kama meaning moon, but it could also be derived from kumr meaning pale green. Abu el Fadel, an Arab traveller, writing around A.D. 1098 suggested that the mountains are so called, "because the eye is dazzled by the great brightness" He goes on to explain that:
"Some have said that certain people have reached these mountains and ascended there and looked over the other side where they saw a sea with troubled waters, dark as the night. This sea being traversed by a white stream, bright as the day which enters the mountains from the north, and passes by the grave of the great Hermes, and Hermes is the prophet Idrisi.
It is said that Idrisi there built a dome. Some say that people have ascended the mountains and one of them began to laugh and clap his hands and threw himself down the other side of the mountain. The others were afraid of being seized with the same fit and so came back. It is said that those who saw it saw bright snows like white silver gleaming with light. Whoever looked at them became attracted and stuck to them until they died and this science is called human magnetism.
It is said that a certain king sent an expedition to discover the Nile sources and they reached copper mountains and when the sun rose the rays reflected were so strong they were burnt.
It is said that in the days of Am Kaam, one of the kings of Egypt, Idrisi was taken up to heaven and he prophesied the coming of the flood so he remained on the other side of the equator and there built a palace on the slopes of Mount Gumr. He built it out of copper and made 85 statues of copper, the waters of the Nile flowing through the mouths of these statues and then flowing into a great lake and thence to Egypt"
The white stream on the black sea sounds to me like a description of the Milky Way, as though this is a legend about the edge of the world, where the earth meets the sky.