During the interval between the two expeditions of Lander to trace the course of this mysterious river, France was exploring its upper waters.

In 1827, Rene Caillie, a Frenchman, adopting the disguise of a Mahometan, left the western coast at Kakundy, a few miles north of Sierra Leone, and crossed the intervening highlands to the affluents of the Niger, which he struck within two hundred and fifty miles of the coast.

He first came to the Tankesso, a rapid stream flowing into the Niger just below its cascades, and noticed here a mountain of pale pink quartz in regular strata of eighteen inches in thickness, a few miles below which the river flows in a wide and tranquil stream through extensive plains, which it fertilizes by its inundations.  One hundred miles below, at Boure, were rich gold mines within twenty miles of the Niger.  In the dry season, he found its waters very cold and waist-deep.

Caillie travelled by narrow paths impervious to horses or carriages, and with a party of natives bearing merchandise on their heads.  His route was through a country gradually ascending and occasionally mountainous, but fertile in the utmost degree, and watered by numerous streams and rivulets which kept the verdure constantly fresh, with delightful plains that required only the labor of the husbandman to produce everything necessary for human life.

Proceeding westward, he reached the main Niger, which he found, at the close of the dry season, and before it had received its principal tributaries, nine feet deep and nine hundred feet in width, with a velocity of two and a half miles an hour.

To this point, where the river becomes navigable for steamers, a common road or railway of three hundred miles in length might be easily constructed from Sierra Leone; and it is a little surprising that Great Britain, with her solicitude to reach the interior, should not have been tempted by the fertility, gold mines, and navigable waters in the rear of Sierra Leone, so well pictured by Caillie, to open at least a common highway to the Niger, an enterprise which might be effected for fifty thousand pounds.  Although this may be so easily accomplished, the principal route to the interior of Africa is still the caravan track from Tripoli through the Desert, requiring three months by a hazardous and most fatiguing journey of fifteen hundred miles.  The first movement for a road to the interior has been recently made in Yarriba, by T.J.  Bowen, the American Baptist missionary, who pronounces it to be the prerequisite to civilization and Christianity.