In the persistence of certain forms which were the direct result of the structure of a building or object, we have a very considerable source of decoration. In Greek architecture many of the details are entirely the product of wooden construction translated into stone. The triglyphs, the imitation of nail heads, of the ends of the poles supporting the roofing, of the crossing of beams at the coffers, are all details which are retained as decoration long after they ceased to have any structural meaning, owing to an entire change of material. Such is structural decoration in its best known forms. But the same principles equally apply to Egyptian architecture; there the original material was not sawn wood as in Greece, but rather the papyrus and palm branch, with the ever-present mud plastering and mud bricks. The decorative details of the stone architecture have come down from this stage of building, translated point for point into stone, just as the Greek translated his wooden architecture into marble. But pottery preceded stone in Egypt, and one of the simplest of ornaments arose from structural necessity. To this day may be seen in the Egyptian pottery yards bowls and jars held together by a twist of rough palm fibre cord, while they dry in the sun before baking. This accidental marking by the rope in the wet clay is seen on the pottery of all ages; but it became developed as a pattern apparently in the twist or guilloche, which may perhaps be rather derived from this than from the chain of coils or wave pattern. [Illustration: 169.—H.S. 383.] [Illustration: 170.—Kahun Pot.] [Illustration: 171.—L.D. II. 63.] Basket-work was elaborately developed in the Old Kingdom. There were beautiful screens represented behind the figures of the owners of the early tombs; they might in some cases be matting instead of basket-work, but others of the patterns appear certainly to be of a rigid material. In no case are they likely to be “mats on which the kings stand,” as styled by Owen Jones. Among the various patterns of platting which are readily developed, squares, waves, zig-zags, chequers, &c., there are some made by binding the fibres into bundles, and so making a kind of open work, which may well have led to the pattern of connected rhombs which is so usual on Oriental pottery. [Illustration: 172.—L.D. II. 63.] [Illustration: 173.—L.D. II. 17.]