At his children's request, one of Britain's poet laureates (1813-43) explains ""How does the Water/Come down at Lodore?""--a waterfall at the upper end of Derwentwater, also a favorite haunt of Beatrix Potter's. ""And moreover he tasked me/To tell him in rhyme."" The indulgent father complies, ""For of rhymes I had store...Because I was Laureate/To them and the King."" Rhymes indeed, cascading as uninhibited as falling water! Southey begins gently as the water trickles from its source, then accelerates with the precipitous descent: ""And pouring and roaring,/And waving and raving,/and tossing and crossing""--to breathless, and hilarious, length. Meanwhile, Gerstein's paintings are as lovely and as deftly drawn as they are comical; he pictures the poet and his children in a miraculous journey--along with the water, the children sporting with fish, umbrellas, and a paper hat that becomes a boat for the family cat while their father, crowned with laurel and quill in hand, diligently pursues his versifying. Adding to the fun, several pages turn sideways to create tall double spreads. A delightfully merry romp. Glossary.