So the merchants held solemn conclave, the result of which was the formation, in 1792, of "The Preventative Service," a title which clung to the members thereof until 1839, when they were embodied with the Metropolitan Police with the special privilege of posing as City constables. Now they are a body of two hundred and two strong, possessing twenty-eight police galleys and a trio of steam launches. From a million pounds' worth of property stolen yearly a hundred years ago, they have, by a persistent traversing of a watery beat, reduced it to one hundred pounds. Smuggling is in reality played out, though foggy nights are still fascinating to those so inclined; but now they have to be content with a coil or two of old rope, an ingot of lead, or a few fish. Still the river-policeman's eye and the light of his lantern are always searching for suspicious characters and guilty-looking craft. [Illustration: IN THE CELLS.] In High-street, Wapping, famous for its river romances, and within five hundred yards of the Old Stairs, the principal station of the Thames Police is to be found. The traditional blue lamp projects over a somewhat gloomy passage leading down to the river-side landing stage. To us, on the night appointed for our expedition, it is a welcome beacon as to the whereabouts of law and order, for only a few minutes previously half a dozen worthy gentlemen standing at the top of some neighbouring steps, wearing slouched hats and anything but a comforting expression on their faces gruffly demanded, "Do you want a boat?" Fortunately we did not. These estimable individuals had only just left the dock of the police station, where they had been charged on suspicion, but eventually discharged. [Illustration: INSPECTOR FLETCHER.] It is a quarter to six o'clock. At six we are to start for our journey up the river as far as Waterloo and back again to Greenwich; but there is time to take a hasty survey of the interior of the station, where accommodation is provided for sixteen single men, with a library, reading-room, and billiard-room at their disposal. "Fine night, sir; rather cold, though," says a hardy-looking fellow dressed in a reefer and a brightly glazed old-time man-o'-war's hat. He is one of the two oldest men in the force, and could tell how he lost his wife and all his family, save one lad, when the _Princess Alice_ went down in 1878. He searched for ten days and ten nights, but they were lost to him. Another of these river guardians has a never-to-be-forgotten reminiscence of that terrible disaster, when the men of the Thames police were on duty for four or five nights at a stretch. He was just too late to catch the ill-fated vessel! He was left behind on the pier at Sheerness, and with regret watched it leave, full of merrymakers. What must have been his thoughts when he heard the news? [Illustration: A NIGHT CHARGE.]