one in the yard of their Penitentiary.  One of the late London papers announces the singular fact that on the 12th of September, at the Town-hall, Southwark, there was no charge, either of felony, misdemeanor, or assault, within the extensive district, of five parishes, from the night before.  Crimes of all descriptions had lessened very much; and this decrease, it is said, is owing entirely to the heavy and tedious labor upon the prisoners at the mill.  Orders had been given for the erection of several more in England.

    Salem Register, 1822.

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    Description of the Tread Mill

    Recommended by the Society for the Improvement of Prison
    Discipline.

The annexed engraving exhibits a party of prisoners in the act of working one of the tread wheels of the Discipline Mill invented by Mr. Cubitt, of Ipswich, and recently erected at the House of Correction for the county of Surrey, situated at Brixton.  The view is taken from a corner of one of the ten airing yards of the prison, all of which radiate from the Governor’s house in the centre, so that from the window of his room he commands a complete view into all the yards.  A building behind the tread wheel shed is the mill house, containing the necessary machinery for grinding corn and dressing the flour, also rooms for storing it, &c.  On the right side of this building a pipe passes up to the roof, on which is a large cast iron reservoir, capable of holding some thousand gallons of water, for the use of the prison.  This reservoir is filled by means of forcing pump machinery below, connected with the principal axis which works the machinery of the mill; this axis or shaft passes under the pavement of the several yards, and working by means of universal joints, at every turn communicates with the tread wheel of each class.

The wheel, which is represented in the centre of the engraving, is exactly similar to a common water wheel; the treadboards upon its circumference are, however, of considerable length, so as to allow sufficient standing room for a row of from ten to twenty persons upon the wheel.  Their weight, the first moving power of the machine, produces the greatest effect when applied upon the circumference of the wheel at or near the level of its axle; to secure therefore this mechanical advantage, a screen of boards is fixed up in an inclined position above the wood, in order to prevent the prisoners from climbing or stepping up higher than the level required.  A hand rail is fixed upon this screen, by holding which they retain their upright position upon the revolving wheel, the nearest side of which is exposed to view in the plate, in order to represent its cylindrical form much more distinctly than could otherwise have been done.  In the original, however, both sides are closely boarded up, so that the prisoners have no access to the interior of the wheel, and all risk