at
pleasure.

Whenever we repeat any idea frequently, the mind, by a sort of
mechanism, repeats it long after the first cause has ceased to
operate.[18] After whirling about, when we sit down, the objects about
us still seem to whirl. After a long succession of noises, as the fall
of waters, or the beating of forge-hammers, the hammers beat and the
waters roar in the imagination long after the first sounds have ceased
to affect it; and they die away at last by gradations which are scarcely
perceptible. If you hold up a straight pole, with your eye to one end,
it will seem extended to a length almost incredible.[19] Place a number
of uniform and equi-distant marks on this pole, they will cause the same
deception, and seem multiplied without end. The senses, strongly
affected in some one manner, cannot quickly change their tenor, or adapt
themselves to other things; but they continue in their old channel until
the strength of the first mover decays. This is the reason of an
appearance very frequent in madmen; that they remain whole days and
nights, sometimes whole years, in the constant repetition of some
remark, some complaint, or song; which having struck powerfully on their
disordered imagination, in the beginning of their frenzy, every
repetition reinforces it with new strength, and the hurry of their
spirits, unrestrained by the curb of reason, continues it to the end of
their lives.

SECTION IX.

SUCCESSION AND UNIFORMITY.

Succession and _uniformity_ of parts are what constitute the artificial
infinite. 1. _Succession_; which is requisite that the parts may be
continued so long and in such a direction, as by their frequent impulses
on the sense to impress the imagination with an idea of their progress
beyond their actual limits. 2. _Uniformity_; because, if the figures of
the parts should be changed, the imagination at every change finds a
check; you are presented at every alteration with the termination of one
idea, and the beginning of another; by which means it becomes impossible
to continue that uninterrupted progression, which alone can stamp on
bounded objects the character of infinity. It is in this kind of
artificial infinity, I believe, we ought to look for the cause why a
rotund has such a noble effect.[20] For in a rotund, whether it be a
building or a plantation, you can nowhere fix a boundary; turn which way
you will, the same object still seems to continue, and the imagination
has no rest. Bu