THE SIEGE OF KRISHNAPUR
by J.G. FARRELL
344 pages. Harcourt Brace Jovanovich. $7.95.
When an American novelist wants to demonstrate the naiveté of Americans, he packs his characters off to Europe. This is known as the Henry James gambit. When a British novelist wishes to display the naiveté of Englishmen, he ships his characters out to India. This is known as the E.M. Forster ploy, and nobody has worked it more pointedly than J.G. Farrell, 39, a native of Liverpool and an expatriate himself in such exotic places as Morocco, Mexico and the Canadian Arcticnot...