1. Object of the Mission.

BEFORE I begin my lecture, allow me to express once more, in your presence, my heartfelt gratitude to the Council of the Royal Geographical Society for the high recompense accorded me on the occasion of my last journey in Central Africa.

It is of this journey, its chief incidents, and most important results, that I am about to have the honour of giving some account. Let me first of all explain to you, in a few words, what, from a geographical point of view, was the object of my expedition.

Explorations in Central Africa, made during the second half of the nineteenth century and in the beginning of the twentieth, had left unsolved a very interesting problem: it had been noticed that the level of vast stretches of desert, several hundred miles north-east of Lake Chad, were considerably lower than that of the lake—the difference amounting in some places to 260 feet; besides this, a wide continuous trench, offering the appearance of an old valley—the Bahr El Ghazal—led from the lake to this low-lying ground, and seemed to stretch far away to the north-east, between the mountain groups of Tibesti and Ennedi. On proceeding towards the north-east, an increasing analogy is to be noticed between the malacological fauna of the Chad basin and that of the Nile. Besides which there had been found recently, in the waters of the Chad, a shrimp till then only found in the Nile basin—the Palæmon Niloticus, Roux. In short, all these signs appeared to confirm the supposition that the basin of the Chad was not a closed basin, but belonged to that of the Nile, and was a former affluent of the old river on whose banks had sprung up and flourished one of the most brilliant and ancient civilizations of the world.

This was the hypothesis that the French Institute wished to have investigated, and in the early part of 1912 I had the honour to be chosen to undertake the necessary researches. May I tell you how the mission thus entrusted to me fulfilled my dearest wish? From my early youth I had felt myself irresistibly drawn towards Africa, and I was filled with a desire to take a modest share in the discoveries of great explorers, whose intrepid expeditions had revealed to the civilized world some part of the mysterious and immense dark continent.

You doubtless remember how vague, some thirty years ago, was our knowledge of that part of the world. At that time—which now seems so far away even for those then living—I had for chaplain at the grammar-school a holy man who was an ardent patriot; in his Sunday sermons he used to talk to us a little of our duty to God, and still more of our duty to our humiliated country, which was waiting and meditating, as it laboured, on the possible reparation of the iniquities of 1871. His voice, sad at first while he spoke of our disasters and the sufferings of our lost provinces, soon grew eager and thrilled as he showed us the new way to be taken by children, as we then were, to raise the prestige of our flag: he would speak to us of that mysterious Africa, half revealed by Livingstone, Stanley, and Savorgnan de Brazza; and I fancy, after these thirty years, I still hear the sound of the name of Savorgnan de Brazza re-echoing through our humble chapel and thrilling like a bugle-call. Then, of an evening in the class-room, I would ponder over the map of Africa, where amid great blank spaces appeared in the centre of the continent a few geographical features, one of which, coloured in blue, Lake Chad, possessed a singular fascination for me.

Some years later, on leaving Saint-Cyr, I began to look forward to the realizing of my dream: after a first campaign in Madagascar, I was sent out to serve on the banks of the Niger in 1899; and since that date each successive campaign in Africa allowed me to push a little further eastwards, and so get to work on a fresh item of the programme I had set myself to carry out: to establish an accurate geographical liaison between the basins of the Niger, the Chad, and the Nile, and unite by a great transversal line the extreme ends of the routes followed by Nachtigal to Tibesti, Borkou, Wadai and Dar Four.

In 1912 I was ordered to take command of the province of Kanem for the purpose of preparing a projected expedition against Borkou, where the Senoussists had established their chief centre of agitation and anti-French propaganda, and whence they periodically sent out plundering expeditions, which spread ruin and desolation among the peaceful tribes placed under our protection. About the same time, the Académie des Inscriptions et Belles-Lettres entrusted me with the mission I mentioned above, concerning the supposed connection between the basins of the Chad and of the Nile. Of this latter expedition, which lasted five years—1912-1917—I now propose to give you a résumé.