The Glass Sphere Pendulum

I scrambled past the open kitchen doorway and leaped straight onto the lower shelf of the big wooden bookcase! Right between two thick, leather-bound encyclopedias sat a shiny metal frame holding five polished steel balls suspended by whisper-thin strings. It looked like an ancient contraption begging for a demonstration! I stepped up, pulled back the very first shiny metal sphere with both blue paws, and let go with a grand dramatic whoosh. *Clack!* The sphere struck the line, and instant wizardry happened—the middle balls froze dead still, but the fifth sphere shot flying into the air with a silvery ring! My hat bounced back in utter shock as the balls took turns clicking and swinging in hypnotic rhythm. Pure rhythmic magic!