The drawing of the cross-section is not included in this web edition, but the comments are included in full.

                  IDEAL SECTION ACROSS SOUTH CENTRAL AFRICA,
  INTENDED TO SHOW THE ELEVATED VALLEY FORM OF THAT PORTION OF THE CONTINENT.
                    --------------------------------------

                                     WEST.

[Terrain]           [Remarks]

Sea.                CALCAREOUS TUFA.

                    TRAP.  With modern shells, and similar to those now found
                    in the sea adjacent, with strongly magnetic iron ore.

                    MICA SCHIST.  Dipping East.

                    SANDSTONE (like that of East Africa).  The rocks
Pungo Andongo.      of Pungo Andongo are a conglomerate of rounded shingle in
Rocks 4000 feet.    a matrix of sandstone, and stand on horizontal sandstone,
                    on which fossil palms appear.

Fault.

                    RED SHALES CAPPED BY FERRUGINOUS CONGLOMERATE.
                    Soft red shale or "keele".

G| 5000 feet.
R| Water boils
E| at 202°
A|                  On top, ferruginous conglomerate; below that, red shale,
T| 4500 feet.       with banks of gravel.
 | Lake Dilolo.
C|                  TUFA AND TRAP.  In Londa, the bottom of the valley
E| 2500 feet.           is formed of ferruginous conglomerate on the surface;
N| Lake Ngami.          hardened sandstone, with madrepore holes,
T|                      banks of gravel, and occasionally trap;
R|                      south of 12°, large patches of soft
A|                  TUFA.    calcareous tufa, with pebbles of jasper,
L|                      agates, &c., lie on various horizontal traps,
 |                      amygdaloids with analami and mesotype, which is
P|                      burst through by basaltic rocks forming hills,
L|                      and showing that the bottom of the valley
A|                  RADIATED ZEOLITE.    consists of old silurian schists;
T|                      there are also various granitic rocks
E|                      cropping through the trap.
A|
U|                  BASALTIC ROCKS.  Augitic porphyry and basalt,
.|                  with tufa over it.

Place of Great Cataract.

                    MICA SCHIST.  White mica schist dipping west, and gneiss.

5000 feet.  Kalomo.
Water boils         GRANITE.  With black mica.
at 202°

                    MICA SCHIST.  White mica schist and white marble.

Hill tops           TRAP.  Hot fountain; conical hills of igneous rocks,
4000 feet.          containing much mica.
Bottoms 3500 feet.

                    MICA SCHIST.  Pink marble dolomite,
                    on hills of mica schist, of various colours, with trap,
                    schorl in gneiss, kyanite or disthene gneissose mica
                    in the schist.

1500 ft.            COAL IN SANDSTONE.  Specular and magnetic iron
                    on various igneous rocks; finely laminated porphyry;
                    granite; hot fountain.

                    Sandstone overlying coal; trap dykes;
                    syenitic porphyry dykes; black vesicular trap,
                    penetrating in thin veins the clay shale of the country,
                    converting it into porcellanite, and partially
                    crystallizing the coal.  On this sandstone
                    lie fossil palms, and coniferous trees
                    converted into silica, as on a similar rock in Angola.

                    COMPACT SILICEOUS SCHIST.

                    IGNEOUS ROCKS.  Trappean rocks, with hot fountain.

                    CALCAREOUS TUFA.  Arkose, or granitic grit,
                    with modern shells covered by calcareous tufa.
Sea.

                                  EAST.

The heights are given as an approximation obtained from observing the boiling point of water, they are drawn on a scale of 1/10 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.