We have already seen how the gradual discontinuance of transportation (1838-1867) and the abolition of the hulks (1857) caused "Public Works Prisons" to be established at Dartmoor, Chatham, etc. At these places, (where prisoners undergoing penal servitude are incarcerated) the plan of silent associated labour by day, with separate confinement by night, was adopted; and although no relaxation of discipline was allowed, the reform of the criminal, rather than his punishment, was aimed at. Under the modern system the convict spends the first nine months of his penal servitude at Pentonville, or in some other local prison, and during this period is kept to solitary hard labour of an irksome and unproductive description; he is then moved to one or other of the "Public Works Prisons," where his life at once becomes less monotonous. As long as his conduct merits advancement, he is passed through various stages, each more tolerable than the last; most of his work is now done in the open air and in the company of his fellows; and hope lightens his labour, for by constant industry and by an exact observance of the prison rules, he is allowed to earn a partial remission of his sentence, amounting to about a quarter[229] of the whole term. Our penal system may not yet be perfect; but during the late reign prison life underwent a marvellous metamorphosis. Pest-houses have been transformed into sanatoriums where the patients have to submit to a healthy discipline beneficial to the mind as well as to the body; formerly gaol-fever, dirt, and bad food ruined the constitution, whilst evil communications corrupted the mind; now convicts leave their prison physically robust and often morally convalescent. This amelioration of the conditions to which prisoners are subjected has been accompanied, _pari passu_, by a steady decrease in the number of convicts in confinement. When Queen Victoria came to the throne, 43,000[230] of her subjects were convicts, at the present time they number less than 6000,[231] and this in spite of the fact that during the interval the population of these islands has just about doubled itself.