If we consider that the sculpture described is close to a watering-place on the high road to Central Africa, we are reduced to the conjecture, that at that time cattle were not only common in this region, but even that they were the common beasts of burden instead of the camel, which we here look for in vain. Not only has the camel no place among these sculptures, but even among the rude outlines which at a much later period have been made on the blocks around, representing buffaloes, ostriches, and another kind of birds, there are no camels; and it is a well-known fact that the camel was introduced into the western part of Northern Africa at a much later period.[61] [Illustration] There was a similar group on another block of this interesting cliff, but too much effaced to allow the particulars to be distinguished; but the figure of an ass among the oxen was quite clear, as well as that of a horse, which was, however, ill-drawn. Not far off, Overweg found another sculptured stone representing, as the annexed sketch shows, an ox jumping through or falling into a ring or hoop, which I should suppose to have an allegorical meaning, or to represent a sacrifice, rather than, as Mr. Richardson thought, to represent any games of the circus. There was a circle regularly laid with large blocks of rock, at the south-western slope of the cliff: these, I should suspect, belong to the same period as the sculptures before mentioned. To a later period belong innumerable inscriptions in Tefínagh, with which the cliffs on the other side of the valley and overhanging the waterpond are covered. These are mere scribblings, and are interesting merely as they serve to render evident, by contrast, the superior merit and age of the adjacent sculptures. It appeared to me remarkable, that on this side, where the water now principally collects, not a single drawing should be seen; and I formed the conclusion that in more ancient times the water collected on the other side.