The answer would be Hard Labor.
The words 'Hard Labour' describes the punishment exactly. Prisoners were often used as the main work force in quarrying, building roads or labouring on the docks. There were several reasons. Firstly, it was felt that it would teach prisoners the value of hard work; secondly, it would remove the temptation for idle men get up to mischief and thirdly,it would deter others from committing crime.