As shown here in quiet, gently indulgent pictures and five untroubling episodes, the Bimbles are a homey, harmonious family--demonstrated straight off by Mrs. Bimble's initial cake baking session which gets everyone comfortably together in the kitchen. It's the kind of family where Polly searches for the dictionary to look up ""serendipity"" for her brother Willie. (When in the process she comes across some other things she's mislaid, the definition takes on a special significance). Even when Mr. Bimble collects so many musical instruments that his family has to move out of their little house. you never doubt that he will immediately miss them and give most of the collection away to make room for their return. . . . Equanimity restored, Polly serves Willie a bowl of rock stew and at bedtime Polly and Willie turn the tables and tell their parents a story. Throughout the pages fairly hum with contentment--all on one note, but it's a pleasing one.