elegant use of the angle of a third of a right angle so generally in Arab art, is very distinct and characteristic. Yet if patterns were continually re-invented, how is it that no one else hit on this simple element for thousands of years? The very fact that the locality and date of an object of unknown origin can be so closely predicted by its style and feeling in design, is the best proof how continuous is the history and evolution of ornament, and how little new invention has to do with it—in short, how difficult it is to man to be really original. Now we can see a source for most of our familiar elements of design in the decoration which was used in Egypt long before any example that is known to us outside of that land. And it is to Egypt then that we are logically bound to look as the origin of these motives. If, then, we seek the source of most of the various elements of the decoration which covers our walls, our floors, our dishes, our book-covers, and even our railway stations, we must begin by studying Egypt. As our object is the history and evolution of the various elements of decoration, we may classify these elements under four divisions. There is the simplest geometrical ornament of lines and spirals and curves, and of surfaces divided by these into squares and circles. There is the natural ornament of copying feathers, flowers, plants, and animals. There is structural ornament which results from the structural necessities of building and of manufacture: these often result in the perpetuation of defects or copies of defects, like the circle stamped in the plain end of meat tins which is made to imitate the circular patch soldered on to the other end, so trying to establish a balance of appearance. Many architectural devices and difficulties are perpetuated for us in this way long after the original purpose has passed away; such as the cylindrical bosses projecting from the walls in Moslem architecture, which imitate the projecting ends of pillars torn from ruins and built into the wall, though rather too long for the position. The origin and the imitation can be seen side by side at Jerusalem. Structural ornament is therefore often of the greatest historical value as pointing to a condition of things that has since vanished. Lastly, there is symbolic ornament. Some now claim most decoration as having some symbolic or religious meaning; of that I shall say nothing, as it is but an hypothesis. But there is no question of the symbolical intention of many constantly repeated ornaments in Egyptian work, as the globe and wings, the scarab, or the various hieroglyphs with well-known meanings which are interwoven into many designs. CHAPTER II _GEOMETRICAL DECORATION_ _The Line._