helpless condition, allowed him to escape; and after wandering about among the naked rocks and burning sands for some time, he fortunately overtook the caravan. For several days the sky, as I have already observed, was serene, and the weather beautiful; but on their arriving at Wady Gharendel, a small stream which flows into the Red Sea, a few leagues south of Suez, they observed that the tops of the mountains, which now flanked their road on both sides, were at intervals capped with clouds, which sometimes remained stationary during the whole day. This disposition of the atmosphere was soon after succeeded by a violent tempest. A canopy of dark clouds extended itself over the earth—the lightning flashed incessantly—the thunder rolled along the sky—and the rain descended throughout the night with all the weight and fury of a tropical storm. Such tempests, however, are exceedingly rare in that part of Arabia, though they are not, as Burckhardt observes, at all uncommon in the Hejaz; nor, according to Niebuhr, is Yemen much less liable to them. But in the neighbourhood of Mount Sinai there is usually one uniform course of weather throughout the year, the winds blowing briskly during the day, and decreasing with the decrease of light. In the level parts of the desert, where the plain was as unbroken as a calm sea, our traveller observed that curious phenomenon called the _mirage_, or mimic lake, every object within the circumference of which appeared to be magnified in an extraordinary manner, so that a shrub might be taken for a tree, and a flock of birds for a caravan of camels. This seeming collection of waters always advanced about a quarter of a mile before the observers, while the intermediate space was one continued glow, occasioned by the quivering undulating motion of that quick succession of vapours and exhalations which were extracted from the earth by the powerful influence of the sun. The few real springs of water which occurred on the road were all of them either brackish or sulphureous; yet the water they afford is so extremely wholesome, and so provocative of appetite, that few persons are ever afflicted with sickness in traversing these wild inhospitable scenes.