A Rolling Discovery

I leaned over the edge of the coffee table, spotted something shiny below, and carefully climbed down via the textured rug fibers beside the table leg. Tucked right against the skirting board was a polished metal marble, catching the morning light. I squatted down, carefully nudging it forward with both hands. It rolled smoothly along the hardwood seam and bumped softly into the base of a forgotten cardboard tube. Looking closely, I realized the marble could roll right through that tube like a track! I lined them up to see how the slope worked.