Fig. 16.—Egyptian ceiling fret.
tracing out the flowing curve. We have closed curves in such figures as the circle, ellipse, oval, figure of eight, and in the vesica piscis, or fish-shape, the latter being composed of two arcs of a circle of the same radius, touching each other at their opposite extremities. The parabola, hyperbola, &c., are open curves; such figures as the meander ([Fig. 29]), the spiral ([Fig. 24]), the scroll ([Fig. 25]), and the swag or festoon ([Fig. 27]), are also open curves. When the festoon is formed of links and hangs like a chain from two points, it is called a catenary, and is practically identical with the lines of festoons and the loopings of drapery.
Figs. 17 to 20.—Straight-lined ornaments
In the illustrations, we have at [Fig. 30] circles touching each other; this is the framework of some diapers and repeating forms. Next we come to circles intersecting each other. [Fig. 31] is a pattern common alike to Saracenic, Egyptian, and Japanese diapers. [Fig. 32] is a border ornament of the same pattern with a centre.
