This route is just within the limits of the tropical rains. The wet season lasts from May to August, but rain never falls for more than 15 days in any year. Sometimes there is no rain for two consecutive years.
There are no streams, the water sinking into the sand and disappearing within 24 hours after rain has fallen.
During exceptionally hot days small whirlwinds pass in great numbers, and carry across the desert sand and fine debris in columns upwards of 150 feet in height. They have a formidable appearance, but are really almost harmless. A very large one might upset a tent, but this performance represents their maximum effect.
The Bayuda Desert is inhabited merely by wandering Arab tribes, of whom the principal are the Hawawir, Hassania, the Sauarab, the Fadnia, and the Aonia.
They subsist almost entirely by keeping flocks of sheep and goats, and by breeding camels, wandering from spot to spot to the best herbage, at such distance from the wells as enables them to water their animals. They also trap the gazelle—so plentiful in this desert; and after the rains a certain amount of ground is usually cultivated by them, and small crops are obtained.
About 4 miles above Ambugol the wadi (valley or stream course) Abu Gir debouches into the Nile; this wadi takes its rise in the Jebel Gilif about 70 miles from the Nile; water is obtainable from shallow wells along its entire course in its bed; like most of the lower portions of the Bayuda Desert, it is thickly covered with vegetation.
Vegetation.This consists principally of low “samr” bushes (spreading thorny acacia), occasional “sunt” trees (acacia arabica, 20 to 25 feet high), the milk plant (asclepia gigantea), the “marakh” (a green shrub), the “tundub” (a bush, some 15 feet high,), and “heglig” trees (20 to 25 feet high, and often with a diameter of trunk at 5 feet from the ground of 12 to 15 inches), the “mokert” (salvadora persica), and even occasionally the “dom” palm (hyphæne thebaica), of which the “dom” palm, the “usher,” and “marakh” are indicative of water close to the surface.
Firewood.Best suited for firewood are the “sunt,” the “samr,” the “tundub,” and the “heglig,” the wood of the latter, I may mention, being used as the base on which the natives twirl a dry piece of “samr” root with the object of producing fire.
Food for camels.Camels devour eagerly the younger branches of the “samr,” the succulent leaves of the marakh (camel thorn) and el gau (camel grass), both of the last-mentioned being plentiful in the Bayuda; indeed, this is a favourite district for breeding and rearing hagins (the lighter and faster class of camels).
Sheep.Sheep, of which large flocks are owned by the Hassania, Aonia, and other wandering Bedawi tribes of the Bayuda, find, during the dry season even, ample food in the grasses of the plains near Jebel Gilif; whilst the fresher shoots of the marakh and tundub, with the juicy leaves of the usher, provide sustenance for the goats.