To the west of the Nile, whose long silver band, skirted with green, stretches in two great curves across Nubia, rise mountains similar in formation to those of the east — primitive rocks, sandstone cliffs, and volcanic lavas and scoriæ. The

Fig. 92. — Bayuda Steppe.
Scale 1: 8,400,000.

highest groups of summits, Jebel-Magaga, Jebel-Gekdul, and Jebel-Gilif, occupy precisely the centre of the immense circuit, three-fourths of which are described by the course of the Nile between the Sixth Cataract and Dabbeh. Their peaks are said to attain a height of from 3,330 to 3,660 feet. The whole of the space