The Discovery of the Source of the Nile | Page 5

and, lastly, that which
consumes it, (4.) Its Fauna; ending with a few special remarks on the
Wanguana, or men freed from slavery.
Geography
The continent of Africa is something like a dish turned upside down,
having a high and flat central plateau, with a higher rim of hills
surrounding it; from below which, exterially, it suddenly slopes down
to the flat strip of land bordering on the sea. A dish, however, is
generally uniform in shape--Africa is not. For instance, we find in its
centre a high group of hills surrounding the head of the Tanganyika
Lake, composed chiefly of argillaceous sandstones which I suppose to

be the Lunae Montes of Ptolemy, or the Soma Giri of the ancient
Hindus. Further, instead of a rim at the northern end, the country
shelves down from the equator to the Mediterranean Sea; and on the
general surface of the interior plateau there are basins full of water
(lakes), from which, when rains overflow them, rivers are formed, that,
cutting through the flanking rim of hills, find their way to the sea.
Atmospheric Agents
On the east coast, near Zanzibar, we find the rains following the track
of the sun, and lasting not more than forty days on any part that the sun
crosses; whilst the winds blow from south-west or north-east, towards
the regions heated by its vertical position. But in the centre of the
continent, within 5§ of the equator, we find the rains much more lasting.
For instance, at 5§ south latitude, for the whole six months that the sun
is in the south, rain continues to fall, and I have heard that the same
takes place at 5§ north; whilst on the equator, or rather a trifle to
northward of it, it rains more or less the whole year round, but most at
the equinoxes, as shown in the table on the following page. The winds,
though somewhat less steady, are still very determinable. With an
easterly tending, they deflect north and south, following the sun. In the
drier season they blow so cold that the sun's heat is not distressing; and
in consequence of this, and the average altitude of the plateau, which is
3000 feet, the general temperature of the atmosphere is very pleasant,
as I found from experience; for I walked every inch of the journey
dressed in thick woollen clothes, and slept every night between
blankets.
The Number of Days on which Rain fell (more or less) during the
March of the East African Expedition from Zanzibar to Gondokoro.
1860 Days on 1861 Days on 1862 Days on which which which rain fell
rain fell rain fell
*** *** January 19 January 14 *** *** February 21
February[FN#1]12 *** *** March 17 March 21 *** *** April 17 April
27 *** *** May 3 May 26 *** *** June 0 June 20 *** *** July 1 July
22 *** *** August 1 August 20 *** *** September 9 September 18

October 2 October 11 October 27 November 0 November 17
November 20 December 20 December 16 December 6

Flora
From what has been said regarding the condition of the atmosphere, it
may readily be imagined that Africa, in those parts, after all, is not so
bad as people supposed it was; for, when so much moisture falls under
a vertical sun, all vegetable life must grow up almost spontaneously. It
does so on the equator in the most profuse manner; but down at 5§
south, where there are six months' drought, the case is somewhat
different; and the people would be subject to famines if they did not
take advantage of their rainy season to lay in sufficient stores for the
fine: and here we touch on the misfortune of the country; for the negro
is too lazy to do so effectively, owing chiefly, as we shall see presently,
to want of a strong protecting government. One substantial fact has
been established, owing to our having crossed over ten degrees of
latitude in the centre of the continent, or from 5§ south to 5§ north
latitude, which is this: There exists a regular gradation of fertility,
surprisingly rich on the equator, but decreasing systematically from it;
and the reason why this great fertile zone is confined to the equatorial
regions, is the same as that which has constituted it the great focus of
water or lake supply, whence issue the principal rivers of Africa. On
the equator lie the rainbearing influences of the Mountains of the Moon.
The equatorial line is, in fact, the centre of atmospheric motion.
Fauna
In treating of this branch of natural history, we will first take man--the
true curly-head, flab-nosed, pouch-mouthed negro--not the
Wahuma.[FN#2] They are well distributed all over these latitudes, but
are not found anywhere in dense communities.