Instructions for using readily available materials to make working models of different kinds of clocks with suggested experiments to discover how they work.
Grandad tells Sally that he never got dirty when he was her age, but when she winds his watch backwards and turns him back into a little boy he proves to be delightfully untidy.
"Bernie Bridges, the egotistical planner and schemer for a group of fourth-graders at The Rotten School, is determined to outsmart his rival in a pie-eating contest."--Provided by publisher.