The Glass Bubble

Dust floated in the morning beam cutting across the high shelf. A long brass bar held a strange clear capsule clamped tight to its flank. Inside... a bright green drop of liquid, harboring an elusive air bubble. Motionless. I crept close, belly skimming the splintered grain. One curved talon tapped the brass flank. *Tink.* The bubble darted left, defying my stillness. I reared up, planted both foreclaws on the heavy frame, and shoved with calculated force. The spirit level tilted. The pale bubble slid smoothly along the marked glass tube, centering dead between the black twin lines. Held rigid. Level calibrated. Perimeter balanced.