Mayer's earlier bestsellers on ""the great professions"" covered Madison Ave., Wall St., and The Lawyers. His new popularization explores the so-called revolution of the last decade in modern banking and the primary sources are interviews, introductions and answers supplied by PR staffs. In return for their help, Mayer virtually panders to them. When the stink of scandal rises with the subject of Franklin National, he finds its insolvency ""fun to watch"" before dismissing the problem with ""the story is very complicated and many of its details may never be known"" -- at least not here. Mayer is more concerned anyway with such distinctive details of banking as the Louis XV decors, the prize-winning glass architecture, the Yale educations, the soft-collar shirts, the prizes offered to new depositors. His quaint folksy explanation of operations procedures follows his personal check from Picozzi's Service Station in Shelter Island, N.Y:, to first the local branch, then the East Hampton one, to the Clearing House in N.Y.C., the main Manufacturer's Hanover Trust (""Manny Hanny""), and finally to his own branch nine at 43rd and Fifth. He fails to make clear the use of sophisticated money-market instruments, supplying instead a farrago of jokes, anecdotes, success stories, asides. Likewise for lending officers, credit bureaus, auto financing, credit cards, bank examiners, the Fed and international banking. He concludes that ""the case for banks is strong. . . . Much of the grumbling. . .is just another symptom of an America bored enough to bite off its own nose: if it's not perfect, I don't want it. We can no more keep an economy from activities we dislike by prohibiting banks from engaging in them than we could stop drinking by shutting down the saloons."" Uncritical? Reactionary? A veritable carte blanche for those ""hydra-headed holding companies"" with interlocking directorates and their ""control of American industry"" -- who may not all be as benign and all-middle-American as Mayer's friends.