The very notion of the nocturnal jurisdiction implied by the title of that famous Board carries with it a suggestion of secrecy and of an unseen process of justice more or less summary, but invariably sharp and decisive. The members composing the Board were frequently of noble birth, and their official position was not unlike that of the Triumvirs of ancient Rome. Their functions, at the time when the Board first came into being, in the Twelfth Century, were those of police-chiefs and commissioners of sewers. They were responsible thus for keeping watch over the streets by night, and for seeing to the repairing of bridges and highways. In this manner they soon came to acquire an expert knowledge of those parts of the city that needed watching, either on account of the questionable condition of their buildings or else by reason of their being the favourite haunts of the criminal part of the population. Under them, less in the character of ordinary police than of a secret detective force, were the “sbirri,” over whom they assumed special control after the unhappy affair of the conspiracy of the Marquis of Bedmar, the Spanish Ambassador, in 1618, when he plotted the overthrow of the Republic; a design frustrated only on the very eve of its accomplishment. The method employed by the “sbirro” in arresting his man was to throw his cloak over the victim’s head and to lead him, thus muffled and blindfolded, to prison. Occasionally, also, the “sbirro” was the owner of a sponging-house, to which he would conduct his prisoner and there detain him until certain demands were satisfied—much as happened to Captain Rawdon Crawley in “Vanity Fair.” It was in this manner—by muffling with a cloak—that the unfortunate Cavaliere Antonio Foscarini was arrested in 1622, on a charge of conspiring against Venice with the Spanish representatives at the Villa Dolo, the house of Lady Arundel and Surrey, where, together with her husband, she was living for the benefit of their children’s education. The charge was a false one, but Foscarini was strangled for it and his body was afterwards hung up between the Red Columns in the Piazza of St. Mark—the usual place of executions—for the public to gaze upon.