A Vertical Survey

I followed the straight line of the skirting board until it met a white vertical pillar. It turned out to be the base of a bookcase. Before attempting any climb, I tested the firmness of the bottom trim with my hand. It is completely stable. Just beside it, a stack of heavy paperbacks created three distinct, tiered steps. I walked up to the first cover, placed both hands on the embossed spine, and lifted my right leg onto the ledge. The surface gave slightly under my weight, but held firm. From this first step, the expanse of the floor takes on an entirely different geometry. @