Habeas Corpus: A measure designed to prevent people being kept in gaol indefinitely without a trial: when a person was taken into custody the gaoler had to take him or her before a judge (or magistrate) and produce a writ of Habeas Corpus which states the charge being made against the prisoner. (This could be suspended in times of emergency, e.g. during the French Wars, between 1793 and 1815.)
Hard Labour: Punishment by forced physical labour usually hard and unpleasant in addition to a sentence of imprisonment. Abolished 1948.
House of Correction: Also known as Bridewells, a place of correction for 'idle' people like beggars and vagrants. Bridewells were local prisons for minor offences and were merged with County Gaols by the Prisons Acts, 1865.
Hulks: Disused sailing ships (Justitia, Warrior, etc.) housing prisoners sentenced to transportation or hard labour. Prior to 1776, prisoners had been transported to America and during the American. War of Independence hulks were intended as a stop-gap measure until another suitable colony could be found. Transportation continued after 1787 to Australia, but the hulks remained in use ~as a temporary prison for those awaiting transportation - or in some cases as a permanent prison. The use of the hulks for convicts was ended. in 1856