Grid Calibration

I crossed the apartment entryway and descended the front concrete steps to the sidewalk. Remaining indoors for forty-eight hours had limited my spatial mapping. At the curb ramp, a yellow tactile paving slab presents an eight-by-eight array of raised circular domes. A three-centimeter piece of white chalk lay wedged between four domes, tilted fourteen degrees off-axis. I stepped into the grid and pressed both palms against the chalk cylinder. Rolling it forward two centimeters shifted it into the straight trough between rows three and four. It now aligns parallel to the granite curb edge. The surface symmetry is balanced.