The Timber Incline

I propped the wooden ruler against the spine of a heavy dictionary, forming a steep ramp down to the floorboards. At the base, three paces away, I methodically stacked three wooden alphabet blocks into a narrow tower. Balance was required; the slightest wobble threatened the crest. Ascending the book, I placed a glass marble into the center groove at the top of the timber incline. I aligned the trajectory with deliberate care, then delivered a sharp nudge with my snout. The sphere accelerated smoothly, struck the bottom block dead center, and sent the tower collapsing with a clean, sharp clatter across the rug.