are immense hills or accumulations of light sand, such as I have seen near the Oasis Magna, in the Libyan desert. The custom of caravans, when they have the misfortune to meet with such blasts, is to pitch their tents and shelter themselves within them. Whatever may be the quantity of sand, they are always safe if they can reach the summit, or place themselves under covert of a hill. I will mention here an instance of this kind, which, in returning from my first voyage up the Nile to the Second Cataract, along with Mr. Ponsonby, he and I witnessed, on the 14th of April, 1832. We were on the point of going that evening to the Isle of Elephantina, when a violent storm, which, considering the season, though rather too early, I might almost call Khampseen, came on. The whole day had been unusually hazy, the air thick and exceedingly oppressive. The extreme heat of the thermometer was 86° in the shade; at sunrise, 70°; sunset, 74°: 86° was a few degrees higher than we experienced it several days previous and after; and I may also remark, that the day following, the thermometer did not rise above 79°. About five o’clock, an immense cloud of sand came sweeping along with a wind so violent, that a boat which was crossing the river to the island was driven back, and the air became so turbid and impregnated with sand, that it was impossible to distinguish any object ten yards from the bank of the river. We heard the peasants in the fields, seemingly wild with confusion and alarm, calling aloud to each other and for their children; and when the sand enveloped them from our sight, we still heard their cries. A scene so strange and impressive I shall never forget. The gale blew almost directly from the west, and seemed to be a specimen of those which have successively swept before them the hills of light loose sand, which, as the Egyptian traveller will recollect, have completely smothered the cultivated land on the western bank of the river opposite Assuan. We endeavoured to shelter ourselves from it as well as the old windows of our cangia would permit; but the sand penetrated every where, into my bed, arms, instruments, and linen; and even my watch was affected. I felt it in my eyes and between my teeth. I then made the reflection, how awful it would be to encounter such a simoom in the desert. It was by such a storm that the army of Cambyses is supposed to have been overwhelmed, as Dr. Darwin in his “Botanic Garden” most graphically describes it:— Wave over wave the driving desert swims, Bursts o’er their heads, inhumes their struggling limbs, And one great earthly ocean covers all: Then ceased the storm—Night bow’d his Æthiop brow To earth, and listen’d to the groans below. ······Awhile the living hill Heaved with convulsive throes, and all was still.[6]