the very simple expedient of creating a greater danger behind than there
is before. Without ingenuity of contrivance like this, turning one
principle of human nature against another, and making it for the
momentary interest of men to act in a given way, no government could
stand.

I know of nothing which illustrates more perfectly the way by which a
knowledge of human nature is to be turned to account in managing human
minds than a plan which was adopted for clearing the galleries of the
British House of Commons many years ago, before the present Houses of
Parliament were built. There was then, as now, a gallery appropriated to
spectators, and it was customary to require these visitors to retire
when a vote was to be taken or private business was to be transacted.
When the officer in attendance was ordered to clear the gallery, it was
sometimes found to be a very troublesome and slow operation; for those
who first went out remained obstinately as close to the doors as
possible, so as to secure the opportunity to come in again first when
the doors should be re-opened. The consequence was, there was so great
an accumulation around the doors outside, that it was almost impossible
for the crowd to get out. The whole difficulty arose from the eager
desire of every one to remain as near as possible to the door, _through
which they were to come back again_. Notwithstanding the utmost efforts
of the officers, fifteen minutes were sometimes consumed in effecting
the object, when the order was given that the spectators should retire.

The whole difficulty was removed by a very simple plan. One door only
was opened when the crowd was to retire, and they were then admitted,
when the gallery was opened again, through _the other_. The consequence
was, that as soon as the order was given to clear the galleries, every
one fled as fast as possible through the open door around to the one