groups in Southern Egypt gives rise to the transverse chain of the Cataracts, which forms the northern frontier of Nubia proper, and merges near Assuan in the Libyan range. In the syenite and granite formations, here skirted by the rapids,

Fig. 95. — Density of the Population of Egypt.
Scale 1: 6,500,000.

are situated the famous quarries, now abandoned, where the Pharaohs procured the materials for their obelisks, statues, and other huge monolithic blocks. Towards 2 east the same group of hills, whence springs the chain of the Cataracts,