Riot Act felt uncertain of their power to take action to stop the riots without a reading of the Riot Act. After the riots, Lord Mansfield observed that the Riot Act did not take away the pre-existing power of the authorities to use force to stop a violent riot; it only created the additional offence of failing to disperse after a reading of the Riot Act. The Riot Act was read prior to the Peterloo Massacre of 1819, as well as prior to the Bristol Riots at Queen's Square in 1831. Both are held to be related to the Unreformed House of
Peterloo Massacre an ironic comparison to the Battle of Waterloo, which had taken place four years earlier. Historian Robert Poole has called the Peterloo Massacre one of the defining moments of its age. In its own time, the London and national papers shared the horror felt in the Manchester region, but Peterloo's immediate effect was to cause the government to crack down on reform, with the passing of what became known as the Six Acts. It also led directly to the foundation of the "Manchester Guardian", but had little other effect on the pace of reform. In a survey conducted by "The