We need not _set_ to work, because we have done that already, we are
always doing it, unknowingly, and without knowing the reason why. All
ornamentalists are subjective mathematicians--an amazing statement,
perhaps, but one susceptible of confirmation in countless amusing
ways, of which two will be shown.

[Illustration: Figure 2.]

Consider first your calendar--your calendar whose commonplace face,
having yielded you information as to pay day, due day, and holiday,
you obliterate at the end of each month without a qualm, oblivious to
the fact that were your interests less sordid and personal it would
speak to you of that order which pervades the universe; would make you
realize something of the music of the spheres. For on that familiar
checkerboard of the days are numerical arrangements which are
mysterious, "magical"; each separate number is as a spider at the
center of an amazing mathematical web. That is to say, every number
is discovered to be half of the sum of the pairs of numbers which
surround it, vertically, horizontally, and diagonally: all of the
pairs add to the same sum, and the central number divides this sum by
two. A graphic indication of this fact on the calendar face by means
of a system of intersecting lines yields that form of classic grille
dear to the heart of every tyro draughtsman. [Figure 2.] Here is
an evident relation between mathematical fact and ornamental mode,
whether the result of accident, or by reason of some subconscious
connection between the creative and the reasoning part of the mind.

To show, by means of an example other than this acrostic of the days,
how the pattern-making instinct follows unconsciously in the groove
traced out for it by mathematics, the attention of the reader is