Let us now glance briefly at the physical geography of the Nile basin south of Khartoum. Below the tenth degree of latitude, the steppe country is no longer seen. Vast marshes stretch away on either hand, broken by peninsulas and islands of dry land. For 790 miles this is the character of the immediate valley of the White Nile. Between latitudes 5 and 6 the swamps end and the face of the country becomes more like our own land. From this latitude to the equator is a charmingly diversified country, with mountains, valleys, creeks, meadows, and not an extraordinary proportion of swamps. Of course, this region is more healthy than the marshes of the White Nile, but even it has a trying climate.
Here the Nile is a rapid stream, with numerous wooded and rocky islands and long stretches of rapids and cataracts. The forests are neither so vast nor so dense as we imagine tropical forests to be; nor do we find here the majestic trees and the luxuriant vegetation of the Central American forests. The herbage grows with wonderful rapidity, and during the summer months much of the country is covered with grass of amazing height and strength.
On the west and south the great swamp basin seems to end at a crest of high land running northwesterly from the Nile at about latitude 5, crossing the eighth degree of latitude at 150 or 200 miles west of the Nile, and keeping something the same general direction to the steppes of Darfour and Wadai.
The eastern limit of the swamp region is even more conjectural than the western, but we may expect that it will be found within 100 miles of the Nile, and that it is a line running south by west from near the mouth of the Sobat. The total area of the swamp basin may be 25,000 square miles.
Khartoum is the point of rendezvous and departure for all routes into the Soudan. It may be reached from Cairo by two principal routes; one up the Nile valley, the other by the Red Sea and by caravan to Berber on the Nile, 250 miles north of Khartoum. The quicker and probably the cheaper route is by the Red Sea, Suakim and Berber. The journey by this route, allowing three days each at Suakim and Berber, may be made in 32 days. By this route there are but two days of hard marching necessary. The rest of the journey can be made at a comfortable pace. Both of these routes into the Soudan are much frequented. Special difficulties in getting transportation may operate against one or the other of them at different times. This is something to be decided at Cairo.