Police in this Country may be considered as a _new Science_; the properties of which consist not in the Judicial Powers which lead to _Punishment_, and which belong to Magistrates alone; but in the PREVENTION and DETECTION OF CRIMES, and in those other Functions which relate to INTERNAL REGULATIONS for the well ordering and comfort of Civil Society. THE POLICE OF THE METROPOLIS, in every point of view, is a subject of great importance to be known and understood; since every innocent and useful Member of the Community has a particular interest in the correct administration of whatever relates to the Morals of the People, and to the protection of the Public against Fraud and Depredation. Under the present circumstances of insecurity, with respect to property and even life itself, this is a subject which cannot fail to force itself upon the attention of all:--All are equally concerned in the Information which this Work conveys; the chief part of the details in which are entirely novel, not to be found in books, and never laid before the Public through the medium of the Press, previous to the first Publication of this Treatise. It may naturally be imagined, that such an accumulation of delinquency systematically detailed, and placed in so prominent a point of view, must excite a considerable degree of astonishment in the minds of those Readers who have not been familiar with subjects of this nature; and hence a desire may be excited to investigate how far the amazing extent of the Depredations upon the Public here related, can be reconciled to reason and possibility. Four years have, however, elapsed, since these details have been before the Public, and they still stand on their original ground, without any attempt which has come to the Author's knowledge, to question the magnitude or the extent of the evil.--On the contrary, new sources of Fraud and Depredation have been brought forward, tending greatly to increase the general mass of Delinquency.[1] [Footnote 1: See Mr. Middleton's interesting Report on the County of Middlesex, and the extracts from thence in Chapter III. of this Work.] In revising the present Edition, the Author felt a strong impulse to reduce his estimates; but after an attentive review of the whole, excepting in the instances of the Depredations on Commercial Property, (which have been greatly diminished by the establishment of a _Marine Police_, applicable to that particular object,) he was unable to perceive any ground for materially altering his original calculations.--If some classes of Theft, Robbery, and Depredation, have been reduced, others have been augmented; still leaving the aggregate nearly as before. The causes of these extensive and accumulated wrongs being fully explained, and accounted for, in various parts of the Work; a very short recapitulation of them is, therefore, all that is necessary in this Preface.