Mr. Smith is either part Irish or mad for some other valid reason. What happens to him and his kin happens to most of us--but to a considerably lesser degree. However, he has managed to make his daily vagaries larger than life and has given them a flavor at once so antic and manic as to make them irresistible. He is the prototype successful ""failure"" who cannot cope with anything--people, gophers or garden statuary. A West Coast newspaper columnist, he details his copelessness in a fine array of essays which maintain a high level of quality and humor. His wife and two sons are charming and not quite crazy; not yet, anyhow. Never mind that summer sojourn on the Riviera. You'd do better to wrangle a week-end with the Smiths.