To-day I found the veil of my sister-in-law of essential service. Doubled, it shielded my eyes perfectly from the hot wind and sand. It serves also as an excellent protection for the eyes against the flies whilst I am writing. This is the second day of the hot wind. In the evening we heard crickets singing in the scorching sand. At mid-day the thermometer, when buried, rose to 122°° Fahr. We encamped in Wady El-Makmak, where we had good water, far superior to that at Guber. As in nearly all sandy places, a hole is scooped in the sand and then covered over, or left to be filled by the action of the wind after the khafilah is supplied. Two pretty palms point, as with two fingers, to the buried wells of El-Makmak. Some of our people noticed the lizard to-day. This seems to be the omnipresent animal of the Sahara, inhabiting its most desolate regions when no other living creature is seen. It changes in species with the nature of the country. To-day, those seen are large; very soon they will become small, meagre, and will change colour. In the valleys I have observed them nearly the same colour as the sandy soil. Perhaps the beetle is nearly as common as the lizard in the desert, being found in its most arid and naked wastes. It is generally a big, round, black-bottle beetle, which produces a trail in the sand that may be mistaken for that of the serpent. Still the following day we had to cross the same kind of desert, under the enervating influence of the gheblee, or hot wind; the thermometer in the sand reached 130°. Although the camels were eight hours on foot, little progress was made. I stopped an hour to rest in Wady El-Jumar, where were two or three palm-groves. One of the Fezzanees ferreted out a lot of dates, hidden in the sand, and taking some distributed them amongst us. Thus refreshed we pushed on to encamp in Wady El-Takadafah, where there is a well of water, good to drink, but disagreeable in smell, like that of Bonjem. The odour resembles that of a sewer, and is produced by hydrogen of sulphur. We have had good water every day in this sandy tract, and I have no doubt that some may be found in every wady, a little below the surface. Birds begin now to reappear: a few swallows, a dove, and some small twitterers, were seen to give life to the otherwise melancholy wadys. Dr. Overweg examined the sand, which rolled in great heaps on every side, and found it to consist of grains of four kinds,--white, yellow, red, and black; the latter colour caused by the presence of iron. These variegated sands form the basis of sandstone, and may be a decomposition of sandstone. The sand near Tripoli is of a finer sort, consisting mostly of a decomposition of limestone. There is a blue-black earth in the wadys, arising from the wood, a species of crumbling coal.