A comprehensive guide to help the unwitting visitor avoid falling victim to the various and nefarious crimes abound in early 19th-century London. Written by "a gentleman who has made the police of the metropolis an object of enquiry twenty-two years", the book is split into six main chapters: "Out Door Delinquencies", "Inn Door Tricks", "Miscellaneous Offences", "House-Breakers", "Minor Cheats", and "Of Conspirators and Informers", containing within them a multitude of sub-chapters including the rather wonderfully titled offences of "Smashing", "Greeks and Legs", "Private Stills", "Bon Ton", "Box Lobby", and "Pretenders to Literature". The book also features a handy glossary of key vocabulary (two pages of which are featured below). From the Introduction:

When a stranger first arrives in this overgrown city and finds upon alighting at the inn, that he has still some miles perhaps to go before he can see his friends he is naturally anxious for advice how to reach them in safety, with his luggage. But if this be the ease with those who have got friends, what is the dread of such as have a home to seek, business to look after, or place of service to obtain, without a friend to guide their steps, or a candid person to warn them of their danger; to tell them of the precipices, pit falls, and moral turpitude, of a large proportion of the population of this great metropolis?

To supply the place of a living friend, and in some cases to perform the necessary part of one, by directing the stranger in the choice of companions, and what characters he should avoid, I have compiled these sheets; in which will be found "all I know about the matter," and all I could "learn out" by "fine-drawing" of others.