If a son ask bread of any of you that is a father, will you give him a stone?"" The narrator of this uneven novel feels decidedly short-changed as he tries to explain his father to his own son. What he knows took place during the summer of '46 when his father, Buck Hansen, ""hobo engineer,"" salesman, divorced from his mother, kidnapped him on a journey half-way across the country, fleeing from his failures and the bill collector. As in a home movie we are given the scenes: the abduction from the Milwaukee house on the estranged family's moving-in day; the nine-year-old boy and Buck in a '41 Chrysler--the father shouting curses at the other motorists; Buck and his son in a Chicago bar--the father trying to swing a new deal; on the farm in Indiana where Buck grew up, a wild kid, only too anxious to get away from the solid Swedes who despised his recklessness; and on to Long Island and a pathetic attempt to salvage a life with still another woman. The bill collector catches up. They return and that's it. Fade out. One's reaction can only be mixed as the novel seesaws between the author's own pretentious insistence (""Son, listen: I would have you know my father"") and the vivid realism of the set pieces. Buck Hansen him. self is all too believable and we don't want to know one more thing about him.