An answer to Tsuyoshi's question can be found in the Oxford editon of _The Innocents Abroad_ in the afterword written by David E. E. Sloane. According to Sloane: "...joke was an undisguised borrowing from Artemus Ward, Twain's most widely known comic predecessor, who had put the question in the mouth of a vulgar Cockney landlord in his _Artemus Ward in London_ (1867), in reference to Oliver Cromwell's appearing at a spiritualist's seance, and had thus established it as a showman's joke on pretentious manipulation of historical dignity by charlatans." (Afterward, p. 4). --Barb