proceeding to the oft-reported lake beyond the desert, came from
England for the express purpose of being present at the discovery,
and to their liberal and zealous co-operation we are especially
indebted for the success with which that and other objects have
been accomplished. While waiting for their arrival, seven men came
to me from the Batavana, a tribe living on the banks of the lake,
with an earnest request from their chief for a visit. But the path
by which they had come to Kolobeng was impracticable for waggons;
so, declining their guidance I selected the more circuitous route,
by which the Bermangueato usually pass, and, having Bakwains for
guides, their self-interest in our success was secured by my
promising to carry any ivory they might procure for their chiefs
in my waggon; and right faithfully they performed their task.
When Sekhomi, the Bermangueato chief, became aware of our
intentions to pass into the regions beyond him, with true native
inhumanity he sent men before us to drive away all the bushmen and
Bakalihari from our route, in order that, being deprived of their
assistance in the search for water, we might, like the Griquas
above mentioned, be compelled to return. This measure deprived me
of the opportunity of holding the intercourse with these poor
outcasts I might otherwise have enjoyed. But through the good
providence of God, after travelling about 300 miles from Kolobeng,
we struck on a magnificent river on the 4th of July, and without
further difficulty, in so far as water was concerned, by winding
along its banks nearly 300 miles more, we reached the Batavana, on
the lake Ngami, by the beginning of August.
Previous to leaving this beautiful river on my return home, and
commencing our route across the desert, I feel anxious to furnish
you with the impressions produced on my mind by it and its
inhabitants, the Bakoba or Bayeiye. They are a totally distinct
race from the Bechuanas. They call themselves Bayeiye (or men),
while the term Bakoba (the name has somewhat of the meaning of
"slaves,") is applied to them by the Bechuanas. Their complexion
is darker than that of the Bechuanas; and, of 300 words I
collected of their language, only 21 bear any resemblance to
Sitchuana. They paddle along the rivers and lake in canoes
hollowed out of the trunks of single trees; take fish in nets made
of a weed which abounds on the banks; and kill hippopotami with
harpoons attached to ropes. We greatly admired the frank, manly
bearing of these inland sailors. Many of them spoke Sitchuana
fluently, and, while the waggon went along the bank, I greatly
enjoyed following the windings of the river in one of their
primitive craft, and visiting their little villages among the
reed. The banks are beautiful beyond any we had ever seen, except
perhaps some parts of the Clyde. They are covered, in general,
with gigantic trees, some of them bearing fruit, and quite new.
Two of the Baobab variety measured 70 to 76 feet in circumference.
The higher we ascended the river, the broader it became, until we
often saw more than 100 yards of clear deep water between the
broad belt of reed which grows in the shallower parts. The water
was clear as crystal, and as we approached the point of junction
with other large rivers _reported to exist_ in the North, it was
quite soft and cold. The fact that the Zonga is connected with
large rivers coming from the north awakens emotions in my mind,
which make the discovery of the lake dwindle out of sight. It
opens the prospect of a highway, capable of being quickly
traversed by boats, to a large section of well-peopled territory.
One remarkable feature in this river is its periodical rise and
fall. It has risen nearly three feet in height since our arrival,
and this is the dry season. That the rise is not caused by rains
is evident from the water being so pure. Its purity and softness
increased as we ascended towards its junction with the Tamunakle,
from which, although connected with the lake, it derives the
present increased supply. The sharpness of the air caused an
amazing keenness of appetite, at an elevation of little more than
2000 feet above the level of the sea (water boiled at 207½°
thermometer), and the reports of the Bayeiye, that the waters came
from a mountainous region, suggested the conclusion that the
increase of the water, at the beginning and middle of the dry
season, must be derived from melting snow.
All the rivers reported, to the north of this, have Bayeiye upon
them, and there are other tribes on their banks. To one of these,
after visiting the Batavana, and taking a peep at the broad part
of the lake, we directed our course; but the Batavana chief
managed to obstruct us, by keeping all the Bayeiye near the ford
on the opposite bank of the Zonga. African chiefs invariably
dislike to see strangers passing _them to tribes beyond_.
Sebitoane,--the chief who in former years saved the life of
Sechele our chief,--lives about ten days north-east of the
Batavana. The latter sent a present as a token of gratitude. This
would have been a good introduction; the knowledge of the
language, however, is the _best_ we can have. I endeavoured to
construct a raft, at a part which was only fifty or sixty yards
wide, but the wood, though sun-dried, was so heavy it sunk
immediately; another kind would not bear my weight, although a
considerable portion of my person was under water. I could easily
have swam across, and fain would have done it; but, landing
without clothes, and then demanding of the Bakoba the loan of a
boat, would scarcely be the thing for a messenger of peace, even
though no alligator met me in the passage. These and other
thoughts were revolving in my mind as I stood in the water,--for
most sorely do I dislike to be beaten,--when my kind and generous
friend Mr Oswell, with whom _alone_ the visit to Sebitoane was to
be made, offered to bring up a boat at his own expense from the
Cape, which, after visiting the chief, and coming round the north
end of the lake, will become missionary property. To him and our
other companion Mr Murray, I feel greatly indebted,--_for the
chief expense of the journey has been borne by them_. _They_ could
not have reached this point without my assistance; but, for the
aid they have rendered in opening up this field, I feel greatly
indebted; and, should any public notice be taken of this journey,
I shall feel obliged to the directors if they express my
thankfulness.
The Bayeiye or Bakoba listened to the statements made from the
Divine Word with great attention, and, if I am not mistaken,
seemed to understand the message of mercy delivered better than
any people to whom I have preached for the _first_ time. They have
invariably a great many charms in the villages; stated the name of
God in their language (without the least hesitation) to be
"Oreeja;" mentioned the name of the first man and woman, and some
traditionary statements respecting the flood. I shall not,
however, take these for certain, till I have more knowledge of
their language. They are found dwelling among the reed all round
the lake, and on the banks of all the rivers to the north.
With the periodical flow of the rivers great shoals of fish
descend. The people could give no reason for the rise of the
water, further than that a chief, who lives in a part of the
country in the north, called Mazzekiva, kills a man annually and
throws his body into the stream, after which the water begins to
flow.
The sketch which I enclose is intended to convey an idea of the
river Zonga and the lake Ngami. The name of the latter is
pronounced as if written with the Spanish ñ, the _g_ being
inserted to shew that the ringing sound is required. The meaning
is "Great Water." The latitude, taken by a Sextant on which I can
fully depend, was 20° 20´ south, at the north-east extremity,
where it is joined by the Zonga; longitude about 24° east. _We do
not, however, know it with certainty._ We left our waggon near the
Batavana town, and rode on horseback about six miles beyond it to
the broad part. It gradually widens out into a Firth about 15
miles across, as you go south from the town, and in the
south-south-west presents a large horizon of water. _It is
reported_ to be about 70 miles in length, bends round to the
north-west, and there receives another river similar to the Zonga.
The Zonga runs to the north-east. The thorns were so thickly
planted near the upper part of this river, that we left all our
waggons standing about 180 miles from the lake, except that of Mr
Oswell, in which we travelled the remaining distance; but for this
precaution our oxen would have been unable to return. I am now
standing at a tribe of Bakurutse, and shall in a day or two
re-enter the desert.
The breadth marked is intended to show the difference between the
size of the Zonga, after its junction with the Tamunakle and
before it. The farther it runs east, the narrower it becomes. The
course is shewn by the arrow-heads. _The rivers not seen, but
reported by the natives_, are put down in dotted lines. The dotted
lines running north of the river and lake, shew the probable
course of the Tamunakle, and another river which falls into the
lake at its north-west extremity. The arrow-heads shew also the
direction of _its_ flow. At the part marked by the name of the
Chief Mosing it is not more than 50 or 60 yards in breadth, while
at 20° 7´ it is more than 100, and very deep.
The principal disease reported to prevail at certain seasons
appears, from the account of the symptoms the natives give, to be
pneumonia and not fever. When the wind rises to an ordinary
breeze, such immense clouds of dust arise from the numerous
dried-out lakes called salt-pans, that the whole atmosphere
becomes quite yellow, and one cannot distinguish objects more than
two miles off. It causes irritation in the eyes, and, as wind
prevails almost constantly at certain seasons, this impalpable
powder may act as it does among the grinders in Sheffield. We
observed cough among them, a complaint almost unknown at Kolobeng.
Musquitoes swarm in summer, and the Banyan and Palmyra give in
some parts an Indian cast to the scenery.
(Signed) DAVID LIVINGSTON.
_A Brief Sketch of the Geology of the West Indies,
from_ Dr DAVY'S _Lectures on the Study of Chemistry,
drawn up chiefly from the Author's own Observations_.[88]
Communicated for the Philosophical Journal.
Footnote 88: Lectures on the Study of Chemistry, in connection
with the Atmosphere, the Earth and the Ocean, and Discourses on
Agriculture, with Introductions on the present State of the West
Indies, and on the Agricultural Societies of Barbados. By JOHN
DAVY, M.D., F.R.S., &c. London, Longmans. 1850.
In the preceding lecture, I brought under your notice the antagonist
and compensating, or correcting influences of animal life in
preserving the uniformity of composition of the atmosphere. In the
earth we witness influences of the like kind, as it were opposed to
each other, and producing opposite effects. Water, in its operation,
aided by air, may be considered as destructive, wearing away rocks and
mountains, and carrying their comminuted parts to lower levels, and
even into the sea, to be buried in its depths. Fire may be considered
as restorative; acting below the surface, it melts and also
consolidates, according to its degree of intensity, tending to
reproduce crystalline rocks in one instance, and stratified in the
other. Even when it appears most eminently to act according to our
ordinary notions of its operation as a devastating and destroying
agent, for example, in the eruption of a volcano, the ashes which are
discharged into the atmosphere, and are widely scattered by the winds,
even when they fall on the adjoining countries, may help to supply the
place of the old surface-materials, carried away by streams and
floods, and to renovate the soil with new elements of fertility. And
acting in another form and manner, the same power which occasions
volcanic eruptions appears to be productive of another effect, viz.,
the gradual elevation of the bed of the sea, tending to the formation
of new land, of which we seem to have examples in the extension of
certain coasts, and the appearance of rocks and dry land above the
waves, preceded by a gradual diminution of the water over the spots
where these remarkable phenomena occur.
Of most of the geological changes alluded to in the preceding remarks,
the West Indies afford well marked instances.
From the continent of America are to be seen vast rivers flowing into
the sea, turbid with the detritus of the country through which they
have descended in a course of thousands of miles, and discolouring and
freshening the waters with which they mix at an extraordinary distance
from land. Between their mouths on the coasts and their rapids in the
boundary hills of the interior, immense level, or almost level tracts
occur,--marsh, morass, and sandbank, neither land nor water, covered
chiefly with aquatic plants,--tracts formed by deposits from the great
rivers, and commonly of materials somewhat coarser and heavier than
those which are longer suspended and are carried out into the sea in
consequence of their greater fineness.
In many of the islands not only are there rocks to be seen evidently
of volcanic origin--columnar basalt, trachyte, and many varieties of
tufa, but also craters from whence eruptions have taken place, and in
which the fires are hardly yet extinct that once acted, as is
indicated by the hot steams and exhalations still proceeding from
them.
Moreover, in some of these islands, rocks of volcanic origin,
crystalline in their structure, and totally destitute of organic
remains, are associated with others of a perfectly different
character, stratified and abounding in organic remains,--various
species of sea shells and of coral; and it is worthy of notice, that,
in one of the instances in which the appearance is best observed,
viz., at Brimstone Hill, in St Christopher's, the volcanic rock,
flanked by the stratified rock, and the latter--an aggregate of
shells, coral, and calcareous marl, has its strata highly inclined,
tilted up as it were by the former.
Other islands, or parts of islands, occur, in which there are only
partial volcanic traces, and these not so much of volcanic action and
disturbance on the spot, as of materials, such as ashes, thrown up by
volcanoes, and those distant ones. The island Barbados is an example.
Composed in great parts of a calcareous aggregate, in which organic
remains abound, it has very much the character, in its peculiar
features, of having been raised from the bed of the ocean (where it is
certain it was formed), by some mighty force, slowly acting, and
which, it is probable, is acting still.
Nor is there wanting in these seas instances of islands, in which
almost every variety of formation is exemplified. Barbados, in its
smaller portion--the Scotland district, exhibits some interesting
varieties, such as beds of chalk abounding in the remains of
microscopic animalcules, strata of sandstone, some siliceous, some
calcareous; the one without organic remains, containing, however,
deposits of coal and bitumen; the other--the latter having included in
them organic remains, and of a kind to connect them with the
calcareous rock of which the larger portion of the island is formed,
for instance, the spines of echini and the teeth of squali. The larger
islands, Trinidad and Jamaica, Port Rico, and Cuba, yield examples,
still more in point. In Trinidad I am not aware that any volcano, or
crater of one, has been discovered, or any rocks evidently volcanic in
their origin; but from the imperfectly crystalline rocks, destitute of
organic remains and distinct stratification, to clays and marls, to
mud eruptions or volcanoes as these are sometimes called, through
limestones and sandstones stratified, and containing organic remains,
a tolerably well-marked series may be traced. In the adjoining and
smaller island Tobago some of the same series are observable, but in a
broken manner, not a little interesting and instructive. There, highly
crystalline rocks, destitute of organic remains, are in juxtaposition
with others abounding in these remains; coral rock is even found
resting on granite; and in another situation the latter rock is
contiguous to mica slate, in which quartz in mass is not of rare
occurrence.
_On the Differences between Progressive, Embryonic, and Prophetic
Types in the Succession of Organized Beings through
the whole Range of Geological Times._
It was a great improvement in our zoological investigations when the
differences in their relations, according to the various degrees of
affinity or analogy which exist between animals, were pointed out, and
successively better understood. In earlier times, zoologists made no
distinction between the different relations which existed among
animals. Affinity and analogy, so dissimilar in their essential
characters, were constantly mistaken one for the other; and upon the
peculiarities which struck the observer most at first sight, animals
were brought together, sometimes upon the ground of true affinity,
sometimes, also, upon the ground of close analogy; and though
comparative anatomy did put the mistakes arising from such confusion
right, by showing that external appearances were sometimes deceptive,
and that a more intimate knowledge of internal structure was necessary
fully to understand the real relations between animals, there
remained, nevertheless, a degree of uncertainty in many cases, as
long as the principles of affinities and of analogies were not
fully distinguished. Every naturalist now knows that true
relationship--affinity--depends upon a unity in structure, however
diversified the forms may be under which their fundamental structure
is displayed. For instance, the affinity of whales and the other
mammalia was not understood before it was shown that, under the form
of fishes, these animals had truly the same structure as the highest
_vertebrata_.
Again, the forms of _cetacea_ exemplify the analogy there is between
whales and fishes. They are _related_ to mammalia; they are
_analogous_ to fishes; they bear close affinity to the mammals which
nurse their young with milk; they have rather close analogy to the
gill-breathing fishes.
Since the fossil animals which have existed during former periods upon
the surface of our globe, and which have successively peopled the
ocean and the dry land, have been more carefully studied than they
were at the beginning of these investigations; since they are no
longer considered as mere curiosities, but as the earlier
representatives of an order of things which has been gradually and
successively developed throughout the history of our globe, facts have
been brought to light which now require a very careful examination,
and will lead to a more complete understanding of the various
relations which exist between these extinct types and those which
still continue to live in our days. Upon close comparison of these
facts, I have been led to distinguish two sorts of relations between
the extinct animals, and those of our days, which seem to me to have
been either overlooked or not sufficiently distinguished. Indeed, the
general results derived from Palæontological investigations, seem
scarcely to have gone beyond showing that the animals of former ages
are specifically and frequently also generically distinct from those
of the present creation; and also to establish certain graduation
between them, agreeing more or less with the degree of perfection
which we recognise between the living animals according to their
structure.
It is now pretty generally understood that fishes, which rank lowest
among the _Vertebrata_, have existed alone during the oldest periods;
that the reptiles which, in the gradation of structure, rank next
above them, have followed at a later period; that still later the
birds, which, according to their anatomy, rank above reptiles, have
next made their appearance; and that mammalia, which stand highest,
have been introduced last, and even among these the lower families
seem to have been more numerous, before the higher ones prevailed over
them. Man, at last, has been created, only after all other types had
acquired their full development. These facts which, in such generality
are fully exemplified in every country in the order of succession of
the different fossil characteristics of the various geological
deposits, shew plainly that a gradation really exists in this
succession, and constitutes one of the most prominent characters of
the development of the animal kingdom as a whole.
If we investigate, however, this gradation, and the order of
succession of animals more closely, we cannot but be struck with the
different relations which exist between the fossils and the living
animals. Many extinct types have been pointed out as characteristic of
different geological periods, which combine, as it were, peculiarities
which at present are found separately in different families of
animals.
I may mention as such, the _Ichthyosaur_, with their fish-like
vertebræ, their dolphin or porpoise-like general form, and several
special characters reminding us of their close relation to the
Crocodilian reptiles; thus combining characters of different classes
in the most extraordinary manner.
Again, the _Pterodactyli_, in which reptilian characters are combined
with peculiarities reminding us both of birds and bats.
Again, the large carnivorous fishes of the coal period, combining
peculiarities of the _Saurians_, with true fish characters; and so on.
These relations are of an entirely different kind from those which I
have pointed out between some of the older fossils and the early stage
of growth of the living representatives of the same families.
For instance, the fossil fishes with a heterocercal tail, found below
the new red sandstone, down to the lowest deposits, reminds us of the
peculiar termination of the vertebral column in all fish embryos of
species living in the present period, to whatever family they may
belong, indicating a similarity of structure in the oldest
representative of this class, with the earliest condition of the germs
of those animals in our days.
Let us now examine whether we can properly understand the bearings of
these relations, and the meaning of such differences.
In the first place, I have mentioned the gradual progress, which is
observed in the succession of the different classes of _Vertebrata_.
This progress is exemplified by a series of types which differ from
each other, but which shew, when arranged in a series, a gradation
which agrees in general with the structural gradation, which we may
establish upon anatomical evidence. For instance, the salamanders,
with their various forms, rank below the tailless _Batrachians_.
And where we have a succession of those animals in the tertiary
deposits as they occur in various parts of Europe, we may fairly say
that the fossils form, in their succession, a series of progressive
types.
Another example may perhaps illustrate the point more fully. The
_orthocera_ of the oldest periods precede the curved lituites, which,
in their turn, are followed by the circumvolute nautilus. Here, again,
we have a natural gradation of a series of progressive types. Again,
among _crinoids_, we find, in the older deposits, a variety of species
resting upon a stem, while free crinoids begin to appear only during
the secondary deposit and prevail, in the present creation, over those
attached to the soil. Here, again, we have a series of progressive
types developed successively, which are apparently independent of each
other and seem to bear no other relation to each than that arising
from the general character of the group to which they belong. Such
types exemplify simply in the groups to which they belong, a real
progress in the successive development of the peculiarities which
characterise them as natural divisions among animals. Such forms I
shall call _Progressive Types_.