Ancient Egyptian quarrying is seen under its most striking aspect among extensive limestone or sandstone ranges, as at Turra and Silsilis; but the process by which the stone was extracted can nowhere be more distinctly traced than at Assûan. In some respects, indeed, the quarries here, though on a smaller scale than those lower down the river, are even more interesting. Nothing surprises one at Silsilis, for instance, more than economy with which the sandstone has been cut from the heart of the mountain; but at Assûan, as the material was more precious, so does the economy seem to have been still greater. At Silsilis, the yellow cliffs have been sliced as neatly as the cheese in a cheese-monger’s window. Smooth, upright walls alone mark the place where the work has been done; and the amount of débris is altogether insignificant. But at Assûan, when, extracting granite for sculptural purposes, they attacked the form of the object required and cut it out roughly to shape. The great obelisk is but one of the many cases in point. In the same group of rocks, or one very closely adjoining, we saw a rough-hewn column, erect and three parts detached, as well as the semi-cylindrical hollow from which its fellow had been taken. One curious recess from which a quadrant-shaped mass had been cut away puzzled us immensely. In other places the blocks appeared to have been coffer shaped. We sought in vain, however, for the broken sarcophagus mentioned in Murray. But the drifted sands, we may be sure, hide more precious things than these. Inscriptions are probably as abundant here as in the breccia of Hamamat. The great obelisk must have had a fellow, if we only knew where to look for it. The obelisks of Queen Hatshepsu, and the sarcophagi of famous kings, might possibly be traced to their beds in these quarries. So might the casing-stones of the Pyramid of Menkara, the massive slabs of the Temple of the Sphinx, and the walls of the sanctuary of Philip Aridæus at Karnak. Above all, the syenite Colossus of the Ramesseum and the Colossus of Tanis,[52] which was the largest detached statue in the world, must each have left its mighty matrix among the rocks close by. But these, like the song of the sirens or the alias of Achilles, though “not beyond all conjecture,” are among the things that will never now be discovered. As regards the process of quarrying at Assûan, it seems that rectangular granite blocks were split off here, as the softer limestone and sandstone elsewhere, by means of wooden wedges. These were fitted to holes already cut for their reception; and, being saturated with water, split the hard rock by mere force of expansion. Every quarried mass hereabouts is marked with rows of these wedge-holes.