sturdier, as in the
Roman Colosseum, or in the Palazzo Uguccioni, in Florence--to mention
only two examples out of a great number. In the Riccardi Palace
an effect of increasing refinement is obtained by diminishing the
boldness of the rustication of the ashlar in successive stories; in
the Farnese, by the gradual reduction of the size of the angle quoins
(Illustration 30). In an Egyptian pylon it is achieved most simply by
battering the wall; in a Gothic cathedral most elaborately by a
kind of segregation, or breaking up, analogous to that which a tree
undergoes--the strong, relatively unbroken base corresponding to
the trunk, the diminishing buttresses to the tapering limbs, and
the multitude of delicate pinnacles and crockets, to the outermost
branches and twigs, seen against the sky.

RADIATION

The final principle of natural beauty to which the author would call
attention is the law of _Radiation_, which is in a manner a return
to the first, the law of _Unity_. The various parts of any organism
radiate from, or otherwise refer back to common centers, or foci,
and these to centers of their own. The law is represented in its
simplicity in the star-fish, in its complexity in the body of man; a
tree springs from a seed, the solar system centers in the sun.

The idea here expressed by the term "radiation" is a familiar one
to all students of theosophy. The Logos radiates his life and light
throughout his universe, bringing into activity a host of entities
which become themselves radial centers; these generate still others,
and so on endlessly. This principle, like every other, patiently
publishes itself to us, unheeding, everywhere in nature, and in
all great art as well; it is a law of optics, for example, that all
straight lines having a common direction if sufficiently prolonged
appear to meet in a point, i.e., radiate from it (Illustration 31).
Leonardo da Vinci employed this principle of perspective in his Last
Supper to draw the spectator's eye to the picture's central figure,
the point of sight toward which the lines of the walls and ceiling
converge centering in the head of Christ. Puvis de Chavannes, in his
Boston Library decoration, leads the eye by a system of triangulation
to the small figure of the Genius of Enlightenment above the central
door (Illustration 32); and Ruskin, in his _Elements of Drawing_, has
shown how artfully Turner arranged some of his compositions to attract
attention to a focal po