IDEAL SECTION ACROSS SOUTH CENTRAL AFRICA. 
INTENDED TO SHOW THE ELEVATED VALLEY FORM OF THAT PORTION OF THE CONTINENT. 
Prepared with the assistance of the Geological Survey of Britain. 
The heights are given as an approximation obtained from observing the boiling pomt of water; they are drawn on a scale of of an inch per 1000 feet in altitude. 
The section is necessarily exaggerated in longitude, as it was traversed in different latitudes; the western side being in 8°—12°, the eastern 15°_18° S. 
To face page 569. 
