A poet popular in German-speaking countries is introduced to American children in pleasant renderings attractively set and charmingly illustrated. The poems vary in content, in freshness, in pertinence. Sure to please is ""The Three Sparrows"": ""At left is Erich, at right is Franz,/ and smack in the middle is smarty Hans. . . They snuggle closely together, all three--/ but Hans is the warmest, none snugger than he!"" ""The Skating Ducks"" offers gentle amusement, and so, more ingeniously, does ""A Visit to the Mouse Barber,"" while ""When Winter Comes"" is sharply imagined, the pebble skipping across the ice, the fishes pressing their noses underneath to see, perchance to eat. . . ""But no! You fishes are too bold;/ you merely get your noses cold."" Others echo time-worn themes of juvenile verse (""The Scarecrow,"" ""The Elephant""), some of which are no longer timely (""The Little House by the Train Tracks""); in a few instances the treatment is itself old-fashioned (""The Loyal Bicycle""). And there are instances in which the interior imagery or the ending seems to have rhyme as its only reason. But the book looks lovely, and the verse at its least auspicious is no worse than much of what's around, which makes it, on balance, a better buy.