Dec. 22.—We moved before daylight, passing some rough sand hills, mixed with red stone, to the west, over a plain of fine gravel, and halted at the maten, called El-Hammar, close under a bluff head, which had been in view since quitting our encampment in the morning. Strict orders had been given this day for the camels to keep close up, and for the Arabs not to straggle—the Tibboo Arabs having been seen on the look out. During the last two days, we had passed on an average from sixty to eighty or ninety skeletons each day; but the numbers that lay about the wells at El-Hammar were countless: those of two women, whose perfect and regular teeth bespoke them young, were particularly shocking; their arms still remained clasped round each other as they had expired; although the flesh had long since perished by being exposed to the burning rays of the sun, and the blackened bones only left: the nails of the fingers, and some of the sinews of the hand, also remained; and part of the tongue of one of them still appeared through the teeth. We had now passed six days of desert without the slightest appearance of vegetation, and a little branch of the souak was brought me here as a comfort and curiosity. On the following day we had alternately plains of sand and loose gravel, and had a distant view of some hills to the west. While I was dozing on my horse about noon, overcome by the heat of the sun, which at that time of the day always shone with great power, I was suddenly awakened by a crashing under his feet, which startled me excessively. I found that my steed had, without any sensation of shame or alarm, stepped upon the perfect skeletons of two human beings, cracking their brittle bones under his feet, and, by one trip of his foot, separating a skull from the trunk, which rolled on like a ball before him. This event gave me a sensation which it took some time to remove. My horse was for many days not looked upon with the same regard as formerly.