The White Nile is a grand river between the Sobat junction and Khartoum, and after passing to the south of the great affluent the difference in the character is quickly perceived. We now enter upon the region of immense flats and boundless marshes, through which the river winds in a labyrinth-like course for about 750 miles to Gondokoro. Having left the Sobat, we arrived at the junction of the Bahr Giraffe, thirty-eight miles distant, at 11 a.m. on 17th February. We turned into the river, and waited for the arrival of the fleet. The Bahr Giraffe was to be our new passage instead of the original White Nile. That river, which had become so curiously obstructed by masses of vegetation that had formed a solid dam, already described by me in "The Albert N'yanza," had been entirely neglected by the Egyptian authorities. In consequence of this neglect an extraordinary change had taken place. The immense number of floating islands which are constantly passing down the stream of the White Nile had no exit, thus they were sucked under the original obstruction by the force of the stream, which passed through some mysterious channel, until the subterranean passage became choked with a wondrous accumulation of vegetable matter. The entire river became a marsh, beneath which, by the great pressure of water, the stream oozed through innumerable small channels. In fact, the White Nile had disappeared. A vessel arriving from Khartoum in her passage to Gondokoro would find, after passing through a broad river of clear water, that her bow would suddenly strike against a bank of solid compressed vegetation--this was the natural dam that had been formed to an unknown extent: the river ceased to exist. It may readily be imagined that a dense spongy mass which completely closed the river would act as a filter: thus, as the water charged with muddy particles arrived at the dam where the stream was suddenly checked, it would deposit all impurities as it oozed and percolated slowly through the tangled but compressed mass of vegetation. This deposit quickly created mud-banks and shoals, which effectually blocked the original bed of the river. The reedy vegetation of the country immediately took root upon these favourable conditions, and the rapid growth in a tropical climate may be imagined. That which had been the river bed was converted into a solid marsh. This terrible accumulation had been increasing for five or six years, therefore it is impossible to ascertain or even to speculate upon the distance to which it might extend. The slave-traders had been obliged to seek another rout, which they had found via the Bahr Giraffe, which river had proved to be merely a branch of the White Nile, as I had suggested in my former work, and not an independent river.