Section Iv.—Wadi Rayan and Neighbourhood—

Colonel Western’s survey. Sir William Willcocks’ report. Borings. Details of proposed reservoir. Schweinfurth’s estimate of salt content. Willcocks’ “Assuan Reservoir and Lake Moeris.” Detailed geological examination not yet undertaken. Traverse from Nile Valley through Wadi Muêla and Rayan to Gharaq. Warshat el Melh and springs of Wadi Muêla. Der el Galamûn. Pass from Muêla to Rayan. Sand accumulations. Wadi Korif. Springs of Wadi Rayan. Analyses and output of water. Geological succession in Wadi Rayan. General geology of floor and bounding walls. Ridge separating Rayan and Gharaq. Apparent absence of Nile deposit and freshwater shells in Wadi Rayan. Question of leakage through ridge. Permeability of Rayan if used as a reservoir. Salinity of water 16