Navigation. 33 spacious basin, which appears, from a communication made to me by Schweinfurfch, to have had no existence at the time of his explorations (1869-71). Farther on follows another expanse of stagnant waters, beyond which the open channel contracts at first to 50 or 60, and then to a little over 20 yards. Here, also, the woods become thinner, and at last again give place to boundless flooded grassy plains, with patches here and there of tall ambach.

" In the narrow channel we were again delayed two hours by a mass of sudd about 160 yards deep, above which the stream broadens to 55 yards ; but nothing is visible except an endless expanse of grass and ambach. At this season the stouter ambach stalks grow to the thickness of an arm, or even a leg, and rise from 12 to 18 inches above the water. From the top sprouts the tufty foliage, the stem proper, from 10 to 15 feet long, lying below the surface.

"In the vicinity of the arboreal vegetation shallow water may generally be expected, whereas the ambach reed often shoots up from considerable depths. Just now it was beginning to blossom, and the tufts were already in many places covered with a pretty yellow flower. With the extremely light stalks the Shilluk negroes make their primitive river craft. The plant is not an annual, but lasts several years, and when full grown attains a height of 16 feet. In its lower part the stem bulges out to a thickness of 10 or 12 inches ; it greatly resembles the Indian Aeschynomene, which is used for making summer head-gear, dainty toys, house models, and the like. Hence ambach is certainly one of the future resources of Africa, as a material that may comeinto use for technical purposes. The tangle of felt-like root fibre growing about the foot of the stem is built of little bulbs or tubers, Avhose purpose is not quite evident, as they neither produce sprouts nor appear to increase the buoyancy of the fibrous radicles.

" Towards sunset of the 27th February we passed the confluence of the River Jur coming from the south-west, and next day brought us to the end of our journey. During the last few hours the Bahr el Grhazal had in many respects again assumed a different aspect. Beyond the mouth of the Jur there was little to suggest a river (386) d