Hidden Cardboard Arches

The torn flap of the delivery box was hanging half-open! I scrambled up the folded crease and gripped a loose edge of the brown outer paper with both hands. With a steady heave—rrripp!—the top skin peeled clean away, uncovering a hidden row of wavy corrugated flutes underneath! They looked like a colonnade of tiny, perfect paper arches marching across the edge in geometric rhythm! I ducked down on my hands and knees to peer straight down the hollow slots. The afternoon light beamed right through each miniature tunnel like a row of glowing portholes! I pressed my thumb firmly against the center arch to test its strength, and it sprang right back against my palm without collapsing at all. Isn't that the neatest little paper bridge ever?