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 a seditious libel. Percy Bysshe Shelley was in Italy and did not hear of the massacre until 5 September. His poem, "The Masque of Anarchy", subtitled "Written on the Occasion of the Massacre at Manchester" was sent for publication in the radical periodical "The Examiner" but because of restrictions on the radical press, was not published until 1832, ten years after the poet's death. The immediate effect of Peterloo was a crackdown on reform. The government instructed the police and courts to go after the journalists, presses and publication of the "Manchester Observer." Wroe was arrested and charged with producing