The torture which many of the wretched prisoners underwent was inflicted for the most part in the famous Bombec Tower, beneath which existed what were called _oubliettes_, or dungeons in which prisoners were subjected to diabolical cruelty. These dungeons bristled everywhere with sharp sword-blades; they were inhabited by rats and loathsome reptiles; and the wretch who was thrown into them found, amidst other horrors, that the waters of the Seine crept in upon him as the tide rose. One of the cells of this tower, into which no light could penetrate, had been occupied by Ravaillac. In modern times the Conciergerie has been rendered habitable. The dark and humid cells constructed at the foot of the towers have been either filled up or suppressed. Already some years ago it was boasted that, with one exception, the Conciergerie contained no dungeon into which the light of day could not steal. * * * * * The Mazas prison, situated on the boulevard of the same name, dates from 1850. The official name is “The house of cellular arrest.” The administration abandoned in 1858 the original designation of Mazas prison, on the petition of the family of Colonel Mazas, who was killed at Austerlitz. But custom is more powerful than any administration; and to the public this gaol is to-day still known solely by the name of Mazas. Its construction, commenced in 1845, was not terminated till five years later. The cost of so vast a prison was naturally enormous. It was intended in the first instance to replace the prison of La Force, then situated in the Rue Pavée-aux-Marais and the Rue du Roi-de-Sicile. The ground on which the first constructions were raised had previously been occupied by market-gardeners and by a mill, which was demolished. The works progressed rapidly under the direction of the architects, Gilbert and Lecointe. Interrupted by the Revolution of 1848, they were resumed shortly afterwards, and on the 19th of May, 1850, took place the inauguration--if this word can be employed in so sinister a sense--of the new prison; the installation, that is to say, of the prisoners. Less than twelve hours sufficed to transfer eight hundred and forty-one convicts in cellular vans, to establish them in their new abode, and inscribe their names, and other particulars concerning them, in the books of the gaol. [Illustration: ENTRANCE TO LA GRANDE ROQUETTE.]