The Enquiry into the Causes of the Frequent Executions at Tyburn was originally published as a series of letters to the British Journal. The first letter appeared on February 27, 1725; just twelve days before, Jonathan Wild, self-proclaimed "Thief-Catcher General of Great Britain and Ireland," had been arrested and imprisoned in Newgate. Thus the inquiry had special timeliness and forms a part of the contemporary interest in the increasingly notorious activities of Wild. Wild's systematic exploitation of the London underworld and his callous betrayal of his colleagues in criminality (he received £40 from the government for each capital conviction he could claim) had created public protest since at least 1718 when an act (which Mandeville cites in his Preface) directed against receivers of stolen goods was passed, most probably with the primary intention of curtailing Wild's operations. Wild's notoriety was at its peak in 1724-5 after his successful apprehension of Joseph Blake ("Blueskin") and Jack Sheppard, the latter figure becoming a kind of national hero after his five escapes from prison (he was recaptured by Wild each time). The timeliness of Mandeville's pamphlet extends, of course, beyond its interest in Jonathan Wild, who after all receives comparatively little of Mandeville's attention. The spectacle of Tyburn itself and the civil and moral failures it represented was one which Londoners could scarcely ignore and which for some provided a morbid fascination. Mandeville's vivid description of the condemned criminal in Newgate, his journey to Tyburn, and his "turning off," must have been strikingly forceful to his contemporaries, who knew all too well the accuracy of his description.