Practical jokes of this nature have more than once led to serious
results. In the summer of 1812 a report was extensively circulated that
a grand military review was to be held on the 19th of June. Booths were
erected and as many as twenty thousand people assembled, despite the
efforts of the authorities who, when they learned what was happening,
posted men in the several roads leading to the heath to warn the people
that they had been hoaxed. But their efforts were useless. The rumour
was believed and the contradiction ignored; vehicles, horsemen and
pedestrians pushed on to their destination. When, however, the day wore
on without any appearance of the promised military pageant, the crowd
grew angry and then broke out in acts of violence. The heath was set on
fire. Messengers were sent off express to London, and a detachment of
the guards had to be marched down to quell the mob. In the disorder one
poor woman was thrown out of a chaise and picked up in an unconscious
condition.