[64] MARIETTE, _Itinéraire_, p. 179. The pavement of the great temple is now about six feet below the general level of the surrounding plain. At the time when Karnak was built there were in the country buildings which were from ten to fifteen centuries old, to which the architects of the time might have turned for information upon doubtful points. In them the gradual rising of the valley level must have been clearly shown. This want of foresight need cause us, however, no great surprise; but it is otherwise with the carelessness of the architects in arranging their plans, and in failing to compel the workmen to follow those plans when made. "Except in a few rare instances," says Mariette, "the Egyptian workman was far from deserving the reputation he has gained for precision and care in the execution of his task. Only those who have personally measured the tombs and temples of Egypt know how often, for instance, the opposite walls of a single chamber are unequal in height."[65] [65] MARIETTE, _Les Tombes de l'Ancien Empire_, p. 10. The custom of building as fast as possible and trusting to the painted decoration for the concealment of all defects, explains the method most usually taken to keep the materials together. The system of using large dressed stones made the employment of mortar unnecessary. The Greeks, who used the same method and obtained from it such supreme effects, put no mortar between their stones. Sometimes they were held together by tenons of metal or wood, but the builder depended for cohesion chiefly upon the way in which his materials were dressed and fixed. The two surfaces were so intimately allied that the points of junction were almost invisible. The Egyptians were in like manner able to depend upon the _vis inertiæ_ of their materials for the stability of their walls, and their climate was far better fitted even than that of Greece for the employment of those wooden or metal tenons which would prevent any slipping or settlement in the interior of the masonry. The dangers attending such methods of fixing would thus be reduced to a minimum. "In consequence of a dislocation in the walls caused by the insufficiency of the foundations, it is possible, at several points of the temple walls at Abydos, to introduce the arm between the stones and feel the sycamore dovetails still in place and in an extraordinary state of preservation. A few of these dovetails have been extracted, and, although walled in for eternity so far as the intentions of the Egyptians were concerned, they bear the royal ovals of Seti I., the founder of the temple, the hieroglyphs being very finely engraved."[66]