Friday, June 28.—Before we could set out, a guide for the sands was necessary. For that purpose we engaged an old Targee, who professed to know every part of our tract. When all things were ready, it was near eight in the evening; but we were determined to start. Now Mr. Hillman left us for Mourzuk, I felt glad and satisfied, as I had always since our departure been uneasy respecting our property; but with Hillman every thing would be taken care of, and as safe as if we were all present. The interest he took in the mission, and the important duty in taking care of all our concerns, deserve the highest praise from every one. We travelled by moonlight over a sandy soil, with numerous tufts of grass and mound hillocks, covered with shrubs, the surface in many places hard and crusty, from saline incrustation. The old man told us that the mounds of earth were formed by water, as the wadey, at the times of great rain, was covered with water. He further added, that in former times a large quantity of rain used to fall, information agreeing with what we had before received. Saturday, June 29.—At daylight resumed our journey; and a little after sunrise entered among the sand hills, which are here two or three hundred feet high. The ascending and descending of these proved very fatiguing to both our camels and ourselves. The precipitous sides obliged us often to make a circuitous course, and rendered it necessary to form with the hands a tract by which the camels might ascend. Beyond this boundary of the sand hills of the wadey Ghrurbi, there is an extensive sandy plain, with here and there tufts of grass. We observed, for the first time, a plant with leaves like those of an equisetum, and a triginious grass. In the afternoon our tract was on the same plain. There were observable several furrows with strips of grass in tufts. Near sunset began ascending high sand hills; they were as if one heaped upon another. Our guide ran before to endeavour to find out the easiest tract with all the agility of a boy. The presence of nothing but deep sandy valleys and high sand hills strikes the mind forcibly. There is something of the sublime mixed with the melancholy. Who can contemplate without admiration masses of loose sand, fully four hundred feet high, ready to be tossed about by every breeze, and not shudder with horror at the idea of the unfortunate traveller being entombed in a moment by one of those fatal blasts, which sometimes occur. On the top of one of these hills we halted for the night. It was near full moon. Her silvery rays, contrasted with the golden hue of the sand, and the general stillness, gave rise to a diversity of reflections.