Recurring Line and Form
The everlastingly recurring egg and dart moulding and the volute are instances of the harmonious effect of very simple arrangements of recurring line and form. We also get illustrated in these another linear quality in design—that up-and-down movement which gives a pleasant rhythm to the simplest border, and is of especial consequence in all repeating border and frieze designs. The borders of early, ancient, and classical art might be said to be little besides rhythmical and logical arrangements of line. The same rhythmical principle is found in the designs of the classical frieze in all its varieties, culminating in the rhythmic movement of the great Pan-Athenaic procession in that master-frieze of the Parthenon, which, though full of infinite variety and delicate sculptured detail, is yet controlled by a strictly ornamental motive, and constructed upon the rhythmic recurrence of pure line.
The Principle of Radiation
Another great linear principle in design is what is known as the radiating principle, which gives vitality and vigour alike to both arrangements of line and delineations of form. It is emphatically and abundantly illustrated in natural forms, from the scallop shell upon the sea-shore to the sun himself that radiates his light upon it. The palm-leaf in all its graceful varieties demonstrates its beauty, its constructive strength combined with extraordinary lightness, which becomes domesticated in that fragile sceptre of social influence and festivity, the fan, and which again spreads its silken, or gossamer, wing as a suggestive field for the designer. We find the principle springing to life again in the fountain jet, and symbolical of life as it has ever been; by means of the same principle applied to construction the Gothic architects raised their beautiful vaults, and emphasized the structural principle and the beauty of recurring line by moulding the edges of their ribs; while we have but to look at the structure of the human frame to find the same principle there also, in the fibres of the muscles, for instance, the radiation of the ribs, and of the fingers and toes.
