On arrival at Korosko, twenty-six days from Cairo, we started across the Nubian Desert. During the cool months, from November until February, the desert journey is not disagreeable; but the vast area of glowing sand exposed to the scorching sun of summer, in addition to the withering breath of the simoom, renders the forced march of two hundred and thirty miles in seven days, at two and a half miles per hour, one of the most fatiguing journeys that can be endured.