lakes and marshes of considerable extent and of about 1000 feet in
altitude, or 250 or 300 feet higher than the region of the ancient lakes
of Borkou and Djourab, with which it is connected by a continuous
valley, the bed of which, very clearly visible in places, is often
buried in sand. This lake-zone seems to be the end of the great
depression I had crossed two months earlier, between the massifs of Erdi
and Ennedi. Except in the immediate neighbourhood of the springs of
Madadi and around the permanent pool of the Wadi Doum (or Touhou) the
soil is absolutely barren, consisting either of very pure siliceous sand
or of soft friable earth, whitish in colour and as fine as flour, into
which we sank to the ankles at every step, raising thick clouds of
stifling dust. Towards the south stretched chains of shifting sand-
dunes, separating that depression from the last foothills of Ennedi,
while to the north extended endless rocky terraces, in which were
hollowed here and there basins of 1 or 2 square miles, wells of water
impregnated with soda.
_The Holy War._—The Turco-Senoussist propaganda against the French and
English was beginning to make its pernicious effects felt among the
nomads of Borkou and Ennedi. The easy successes achieved by the rebels
against caravans and convoys unprotected by escorts had just given them
a great idea of their military power, and increased their numbers and
audacity. The withdrawal towards their base of the Italian forces in
Tripoli, and particularly the abandonment of Mourzouk, where a
Senoussist governor had taken up his residence, had inflamed the minds
of the Toubous, whose warlike ardour had never burnt so fiercely: it
seemed to them likely that a backward movement of the French occupying
Tibesti, Borkou, and Ennedi would speedly take place if their
commissariat lines were seriously threatened in the direction of Lake
Chad and Wadaï. Turkey’s entrance into the war on the side of Germany
against France and England had counterbalanced the successes won over
the Germans in the Cameroons and deeply stirred the imaginations of
these devout Mohammedans, who refused to recognize any other chief than
the distant Sultan of Stamboul, Caliph of the Prophet and Commander of
the Faithful. And one after another the Duzzas of Borkou, the Gouras of
Gouro, the Arnas of Tibesti, and the Gaïdas of Ennedi fell from their
allegiance.
Now, at that moment the requirements of the escort-service for our
convoys of supplies were such that out of the hundred and sixty men of
each of my companies in Borkou and Ennedi, less than twenty rifles were
sometimes left to guard the posts of Faya and Fada. It was hardly before
the month of April 1915, when the food-transport was almost finished,
that it became possible to remedy this dispersal of our forces and
organize the punitive expeditions rendered indispensable by the
incessant raids of the rebels. That task was an awkward one, for we were
short of good camels and above all of good agents of information, while
our elusive adversary was kept acquainted with our slightest movement by
certain elements of the population theoretically faithful to us.
It would evidently have been too much for us to hope that we should
speedily obtain the submission of the malcontents, given the very
considerable extent of their space for movements of all kinds, and also
their extreme mobility; but we could henceforth return blow for blow,
chase them to their mountain lairs, and give them the impression that,
after playing for some time the pleasant part of hunters, they were
henceforth going to play the much less pleasant one of game.
One after another Captains Lauzanne and Châteauvieux, Lieutenants Lafage
and Calinon, at the head of mixed detachments of regular soldiers and
Arab and Toubou auxiliaries, made their way into the wildest fastnesses
of Eastern Tibesti, Borkou, and Ennedi. Captain Lauzanne, in particular,
succeeded in tracking the Gourmas into the distant solitudes of Ouri,
200 miles north of Gouro, at the foot of the eastern spurs of the
Tibesti, and after them their cousins the Koussadas into the very crater
of Emi Koussi, till then regarded as impregnable. The fame of these two
expeditions was noised abroad in the country to such an extent that by
the end of the month of July the general situation of Borkou had greatly
improved, and we could turn our thoughts to the consolidation of our
prestige by an offensive action against the rebels of Miski, and by a
junction of our troops with those of Zouar and Bardaï, the two military
posts entrusted with the supervision and pacification of western and
central Tibesti.
=7. Exploration of Tibesti.=
In the month of September 1916 I was authorized to proceed from Borkou
to Tibesti for the purpose of getting in touch with the rebel tribes who
intended to attack the caravans fitted out in Kanem and Wadaï for the
carrying of supplies to the garrisons of Borkou and Ennedi. The garrison
of Tibesti was to attempt, to the best of its ability, to co-operate
with this action in such a way that the hostile bands, threatened at
once on the south, the west, and the north, might either be induced to
submit or else to disperse in the eastern part of the Tibestian massif,
the part furthest away from the region to be traversed by our convoys of
supplies.
The rebels were comparatively few in number—about 2000 combatants—and
divided into clans living in different regions; but they were of extreme
mobility, well armed, and abundantly supplied with ammunition. Their
tactics, which were very skilful, consisted in avoiding on all occasions
a fight in the open, in hiding in the labyrinth of their well-nigh
inaccessible rocks to fire at short range on the enemy when he passed
near enough, in decamping at top speed to hide again a little further
on, and so draw little groups of adversaries in the direction of death-
traps, where of course well-planned ambuscades lay in wait for them.
The strength of the reconnoitring detachment was forty-four black
soldiers, officered by four Europeans—one of them a doctor—and
accompanied by some thirty auxiliaries (guides, goumiers,[1] camel
drivers, and servants). It carried food for two months, and the barrels
and skins required for three days’ water. The train included about 120
camels.
The mountainous country to be crossed set an extremely awkward problem:
many points where water would have to be found were often hard for the
camels to reach. Pasture-grounds were rare and scanty. The tracks,
inexistent or deceptive, would now stretch away across successive heaps
of sharp-edged pebbles, and now twist and turn endlessly along winding
torrent beds, deep sunk between sheer banks. To cross from one valley to
the next one had to climb a succession of cliff ledges, rising tier on
tier to several hundred metres by the merest suggestion of paths winding
along the sides of spurs formed by the rolling down of _débris_ from
above; when the slopes grew too steep, the baggage had to be carried up
from one shelf to the next on men’s heads. Our camels, used to the easy
going of the great sandy plains, were discouraged by the asperities of
the sharp-angled rocks, by the narrow ledges, the steep and slippery
steps, the loose pebbles, the excessively sharp turns; and so only short
distances could be covered in spite of long hours under way and intense
fatigue.
It goes without saying that we had no sort of map of these unknown
regions, and that we were utterly at the mercy of the guides whom by
good or evil fortune the patrols put at our disposition. Accordingly,
the choice of our routes was dictated to us at once by the necessity of
reducing to a minimum the efforts and privations of our camels and by
that of keeping within the limits familiar to our ordinary and
occasional guides. It may be added that the latter showed the utmost
unwillingness to lead us into regions where the unsubdued tribes
habitually take refuge; for these tribes are in the habit of holding
them responsible, on their own heads and those of the members of their
families, for all the harm and losses incurred when fights arise with
our detachments.
The general plan of this series of operations included, first of all,
the reconnoitring of Emi Koussi, an extinct volcano 3400 metres high,
followed by an inroad into the valley of Miski, the usual meeting-ground
of the Tibestian freebooters threatening the roads to Kanem. The central
position of the valley is strengthened by the natural shelter afforded
by high mountains and almost impassable rocky foothills, through which
lead only two defiles, both of them long and dangerous.
From Miski I meant to make a rapid plunge into the valley of Yebbi, in
the heart of central Tibesti, firstly to try to get into connection with
a detachment of the garrison of Bardai, and then to make an attempt to
reach the plateaux of Goumeur. Lastly, I thought I might be able to get
over on to the western slope of the massif, explore its chief valleys,
and effect a junction with the Zouar camel corps before returning to
Borkou. I succeeded in carrying out this programme in its main lines,
except for the operation in the direction of Goumeur, which had to be
replaced at the last minute by a reconnaissance pushed as far as the
post of Bardai. I was away, in all, for seventy-two days, or barely a
fortnight in excess of my estimate.
_From the Plains of Borkou to the Foot of Emi Koussi._—The name of
Borkou is given by geographers to the group of low-lying stretches of
country separating the mountain mass of Tibesti from that of Ennedi; it
was confined at first to the depression, some 10 kilometres wide by 100
in length, that extends from east to west, from Faya to Ain Galakka.
This hollow was long filled by a lake, of which numerous and conclusive
traces are still found: beds of lake shells, whole skeletons of fishes
up to a yard and half long, calcareous crust covering long streaks of
rock, platforms of white clay marking the line of flats where the last
pools left by the waters of the former lake have held out longest before
drying up, and so forth. This lake was fed by mighty watercourses,
coming down from the mountains of Tibesti and Ennedi; it poured its
overflow through the valley of the Jurab into the Kirri, the deepest,
largest, and most recently dried up among the ancient lakes and lowlands
of the Chad.
From Borkou to Emi Koussi there is a large choice of routes. The best,
owing to the number of points at which water and pasturage may be found,
is that which passes by way of Yarda to Yono. Hereabouts we leave behind
the region of the oases characterized by numerous depressions in which
water is found close to the soil in practically unlimited quantities, in
wells less than a yard deep and in salt pools. From that point one
enters the rocky zone where there is no more water underground, but only
natural cisterns forming reservoirs with the water that streams down
into them, and dries up a longer or shorter time after the passage of
the accidental rains that filled them.
The general look of the country is fairly uniform. It is a vast
sandstone plateau sloping from north to south, ravined with narrow
gullies running in a general direction from north-east to south-west,
and which are real rivers of sand in which the shifting dunes pile
themselves up and overlap to the point of being impassable at times to
laden beasts of burden. This direction, from north-east to south-west,
being that of the prevailing wind in Borkou, the parallelism of these
gullies and the general appearance of the landscape give colour to the
supposition that they were hollowed out of the sandstone by the erosive
action of the dunes driven before the wind.
The rocky plateau is commanded at intervals by a few blackish peaks of
low relief, among which the most noticeable are those of Kazzar, near
Yarda, 75 metres above the surrounding country; Olochi, near Dourkou,
130 metres; Ehi Kourri, near Kouroudi, 350 metres in relief. From the
height of these natural observatories nothing is to be seen, in whatever
direction one turns, but vast dark-tinted expanses strewn with stones,
where no sort of topographical order can be discerned. So confused and
scattered are the rocky masses that the impression they leave is less
that of a sequence of alternating plateaux and valleys than of a chaos
of disconnected reefs rising above a sea of sand, amid breakers of
billowy dunes. Much going and coming was needed before I could form an
exact notion of the physiognomy of these regions, for the fact is that
their valleys are more or less blocked, at longish intervals, by heaps
of rock debris and sand, and so divided into a succession of elongated
hollows communicating only by subterranean infiltration. In these
hollows may be found, here and there, layers of shells that enable us to
fix the period when they were still underwater at a comparatively recent
and no doubt Quaternary epoch. From place to place there still exist
permanent salt pools, of greater or less depth, and usually at the foot
of the cliffs that shut in some of these valleys on the east. One
supposes that the strong back draughts of the north-east wind have
mainly concentrated their action on those points of the surface where
the sandstone was softest; in the excavations thus produced the sheet of
subterranean water has been able to make its appearance in the open air,
and under the influence of a persistent evaporation, due to the extreme
dryness of the air and the intensity of the solar heat, the salts in
solution in the water have undergone a progressive concentration,
sometimes to the point of floating on the surface of the pool with the
appearance of translucent blocks of ice.
Having left Faya on September 4 we arrived on the 11th at the foot of
Emi Koussi, 125 miles to the north, passing on our way by Korou Koranga,
where we renewed our supply of water. The spot is one of the most
picturesque I saw during this journey to Tibesti; it is a natural
cistern hollowed by the action of the falling waters in the deep and
narrow bed of the wadi Elleboe, a torrential river that comes down from
Emi Koussi. The way to it lies through a defile more than a mile long,
so narrow that two men cannot walk abreast. The water lies at the bottom
of a grotto, dark in spite of being open to the sky, and whose walls
wind in and out in such a way that not only the drying desert winds
cannot get to it, but that even the sun’s rays only penetrate to it for
a few minutes each day about noon, and only get down to the level of the
water during May and July, when the sun reaches the local zenith. I had
neither the time nor the means to measure the length and depth, the
approach between precipitous walls being so difficult; but the supply of
water is such that the cistern has never been dry so long as the guides
can remember, however long may have been the drought during which the
torrent has ceased to flow; the water stays clear, cool, and pleasant to
the taste, without the slightest salty flavour.
The cistern of Derso, on the contrary, at the foot of Emi Koussi, near
the pasturage of Yono, is broad, spacious, and subject to the drying
action of sun and winds; a score of yards deep, it is easy to get at;
but its greenish water, stagnant and thick with organic matter, has to
be filtered before it can be drunk without disgust, and a period of
twelve or fifteen months’ drought is usually enough to dry it up
altogether.
_Ascent of Emi Koussi._—In all probability the rebels of the regions we
had just come through had withdrawn towards their strongholds on the top
of Emi Koussi. A light detachment was sent out to make sure that this
was so, while the greater number of our camels were left to rest in the
pasturage of Yono, where I had a little zeriba built for the storage of
our baggage and provisions and the security of the men I left to guard
them.
On the morning of September 13 we betook ourselves to the ascent of the
mountain by a track strewn with boulders, the gradient being fairly easy
for the first five hours’ march, as far as the salt springs of Erra
Shounga. From that point it stiffened, and grew very steep indeed
between 6000 and 9000 feet. The last part of the ascent to the entrance
of the pass that leads into the interior of the crater required the
utmost effort on the part of our camels, unaccustomed as they were to
the going in mountainous countries.
Sixteen or eighteen hours must be allowed to reach the summit of the
ancient volcano, and one does well to spread them over two days if one
does not want to leave any camels on the way. The first stage should get
one to Fada, a little pasturage at the bottom of a ravine accessible to
camels, and where the animals should be allowed to rest and feed.
Afterwards a fairly long halt should be made at an altitude of about
6000 feet, to renew the supply of water at the natural cistern of
Lantai-Kourou, for there is no hope of finding water in the interior of
the crater; the operation is a long and toilsome one, for the track
leading to the reservoir is inaccessible except to men. Along the whole
way there is hardly any vegetation, such as there is being confined to
deep ravines, almost always inaccessible, except at the pasturage of
Fada, on account of the steepness of their sides. Towards the foot of
the mountain only stunted plants are to be found, with tiny leaves often
sharpened into thorns; while nearer the top the boughs are thicker, the
bark tenderer, the sap more abundant, and the leaves longer and greener.
No trees are to be found on Emi Koussi in the crater itself; on the
other hand, the herbaceous vegetation is comparatively abundant, and
marked especially by the “erendi,” a yellow-flowered plant reminding one
of the St. John’s wort of our regions. We bivouacked, in a good position
for observing all the approaches, in the midst of these bright-hued
flowers, and I cannot tell you with what fascinated eyes we gazed on
them, for none of us had seen their like for three long years.
The temperature was mild and cool like that of a fine spring in France;
but in the clear sky there were no birds, and the sight of the scowling
cliffs around us soon broke the charm under which our fancy would have
gladly lingered.
We stayed only three days in the crater of Emi Koussi. The afternoon of
the first day was devoted to the exploration of a pit, 300 yards deep
and 2 miles in diameter, which was once the chimney of the volcano. A
vast expanse of carbonate of soda covers the bottom, which one can reach
only by a very steep path.
The second day was spent, firstly in exploring, both inside and out, the
western slopes of the crater, where there is a natural cistern that
enabled us to make a fresh provision of water, though the track leading
to the reservoir is very perilous for the camels; and afterwards in
taking certain measurements, such as the height of the cliffs and the
depth and extent of the central pit, called by the natives Era-Kohor, or
Natron Hole.
The third day was given up to explorations in several directions, which
allowed us to visit some recently abandoned troglodyte villages, to
capture two prisoners, and to reach the summit of the northern side of
the volcano, a point from which the whole of the Tibestian mountains can
be seen.
The evenings, nights, and mornings were icy-cold, though the thermometer
never fell below freezing-point. Our camels, taken aback by the novelty
of the grass offered them, cropped it very sparsely; our provisions were
giving out, and the rebels had fled before our arrival into
exceptionally difficult mountainous tracts, where we could not dream of
following them. In a word, in spite of the geographical interest there
would have been in prolonging our stay on the summit of Emi Koussi, when
the fourth day came we had to think about getting back to Yono.
[Illustration: STEEP SLOPES ON THE FLANK OF EMI KOUSSI, TIBESTI]
[Illustration: THE GREAT CLIFF, TIBESTI]
[Illustration: NATURAL CISTERN OF DERSO AT THE FOOT OF EMI KOUSSI]
[Illustration: THE CRATER OF EMI KOUSSI (3400 m.), TIBESTI]
From this excursion on the highest peak of the highest mountain in the
Sahara I brought away an abiding impression of wild magnificence, and
most of all when one’s thoughts go back to the panorama of the Tibestian
mountains. There may, I fear, be something of presumption in attempting
even a short description; still, I will ask your permission to make a
short extract from my diary on the day in question:
“. . . Continuing our march northwards, we soon reach the foot of the
cliffs of the northern wall, where, by a natural staircase, nearly 600
feet in height, one can reach the Tiribon pass, through which run the
difficult paths that lead to Miski, Tozeur, and Goumeur.
“In front of us the volcano slopes steeply downwards, leaving open to
view the Tibestian massif with the endless succession of points of its
serrated ridges outlined against the sky and stretching away out of
sight. On our left the crater-wall loses itself in a confused mass of
rocks, while on the right rise a number of sharp peaks, one of which
seems to be the culminating point of this part of the ring of heights
that shut in the volcano.
“A last effort got us to the top of this lofty summit, 10,000 feet above
the sea, where we found a narrow platform strewn with boulders, with big
clusters of red and lilac tinted flowers growing in the gaps between the
stones. Toilsomely enough, I managed to scramble on to the highest rock,
and as I stood on it, there lay before my eyes, for the first time, the
mysterious Tibestian chains that no explorer had ever gazed on yet in
their majestic entirety. The grandeur and beauty of the sight so far
outdid all I had anticipated that I could not turn my eyes from watching
the harmonious hues thrown over the landscape by the rays of the
declining sun. The intense clearness of the air made it easy to see
distinctly the remotest peaks; all around lay long ridges, their
successive summits rising and falling in regular points like lace;
scattered rocks, deep gorges, dizzy precipices, jagged peaks. Each
mountain range, though all were turned by the sun to the purest rose
colour, had its distinct shade, brightest in the foreground, softening
into mauve as distance melted into distance away to the far horizon.
“Eastwards, the Tibestian massifs fell by giant steps whose sharp-angled
lines, blurred by the first shadows of the waning day, ran into one
another in inextricable tangles; while to the west the mountains
bordered an endless plain, a forbidding waste of stones, over which
brooded and deepened a gloom that threw into beautiful contrast the
rosy-mantled chains whose lofty summits soared into a sky of calm and
exquisite blue.”
Tearing myself away, not without reluctance, from the dreamy fancies
called up by all these glories, I made haste to take a few observations
with compass and thermometer and make a few notes. The Tibestian reliefs
appeared to me to be included in a right angle, the apex of which is
marked by the volcano, and the two sides by the directions W.N.W. and
N.N.E.; such being the case, the appearance of Tibesti was totally
different from what I had till then supposed it to be, on the strength
of the statements put forward by the explorer Nachtigal. The rest of my
journey was to afford me the opportunity of unravelling the skeins of
the succession of ranges, whose apparent position and extent I could now
approximately fix.
On September 18, towards noon, we struck camp, to go down again into the
plain by the route we had followed on our upward march. While the
camels, weary and emaciated, were painfully climbing the slopes of the
pass leading out of the volcano, I took a last all-embracing look at
this huge crater, 10,000 feet above the sea; few others in the world are
so immense, for it is 5 miles wide and 8 miles long, and looks like a
gigantic funnel, almost elliptical in outline, 25 miles round and 800
yards deep; on all sides it is shut in by a rampart of unbroken wall,
rising sheer almost everywhere for 500 or 600 feet, and which can be got
over only at two points, by openings that are very hard to reach.