192 The British Campaign in the Soudan.

an army, which must therefore carry all its supplies, including even forage for its animals.

II. There are no roads and no vehicles in the Soudan —only camel-trails, and every thing must be transported on camel-back. : III. And most important of all, the Soudan is a rainless, waterless land. Away from the Nile there are no rivulets, creeks, or springs—nothing but rare and scanty wells at long intervals, or rocky reservoirs in deep ravines, like those of Gakdul and Abou-Klea, where the rain-water collects during the brief rainy season. Droughts of two and three years’ duration are not uncommon, and had just occurred when I travelled over the deserts on both sides of the Nile in 1873, ’74, and ’75. In such seasons great numbers of cattle, and even camels, perish. No animals are used for transportation except camels, for they alone can travel five days without water, even in summer, and on the caravan routes wells are often that far apart. Consequently water sufficient to supply men (and cavalry and artillery horses in the case of an army) has to be carried in goat-skins which waste a large pro-_ portion by evaporation. From my experience of 6,000 miles of desert travel I judge that every 1,000 men, with the usual proportion of horses in an army, would require 500 camels for water alone, and at least 800 more for ammunition, supplies, forage, etc. This is what renders all long desert routes impossible for a European army. If Gen. Herbert Stewart succeeded, not without much suffering from hunger and thirst, in crossing the level Bahiuda plains (as will be seen later), it was because the distance was only 150 miles, the desert less arid, and the wells much closer than the average ; besides which he had