Abbot invents Mr. Nobody in August, after he fails to measure up to the red line that keeps little kids off the carnival roller coaster, and he refers to him frequently during the year when he is frustrated about being too small, impatient because tomorrow never comes, or just ""all mixed up"" about how soon it is till Christmas. Throughout these 13 monthly episodes Mother tries to talk Abbot into dropping Mr. Nobody, and then in July when a bull gets into their yard it is Abbot--Me! Myself! Not Mr. Nobody!--who dashes to the barn for salt to lure it away. And the following month, about to start school, Abbot suddenly discovers that he can read the numbers on the calendar and has grown without even trying. ""Tomorrow did come after all, he thought."" It's that sort of slight, pat chronicle, in which each little episode is burdened with an overstressed ending. (On a country walk when Abbot finds the way home, older brother Evan states, superfluously, ""I'm sure glad you came with me. I'd have been lost without you."") Unobjectionable, but Abbot's advances are too obviously arranged.