A Curious Roll

I nudged a smooth wooden thread spool across the floorboards. It wobbled, rolled two feet, and clunked gently against the skirting board. I trotted straight after it, lowering my snout to butt it back. Round things just never stay where they belong! As I pinned it under one hoof, a tiny paper circle tucked in the end caught my eye: 'COTTON 50 - YDS 100'. I tapped it twice with my horn before watching it spin again.