The preamble to the law stated that it was necessary "not only for the safe custody of convicted criminals, but to ensure the more important object of their restoration to society, in a state of reformation and improvement, by a uniform course of well regulated labour, and judicious instruction.

"[3] The foundation stone was laid by the Earl of Elgin, the governor, in 1845, and was "so general a holiday we have rarely seen.

"[4] In 1847, the walls enclosing the penitentiary were completed, and work on the cells and hospital began.

[5] It was formerly the General Penitentiary, and was built to accommodate 650 male inmates[6] but has held over 1700 on occasions.

The new penitentiary was designed according to the 'separate system' in which prisoners are held in isolation, although in practice sharing of the small cells has been common.