A Circular Beam

I stepped past the edge of the printed cardboard sheet onto the dark wood surface. A tall, arched metal arm rose nearby, casting a sharp circle of warm light across the desk. I approached the perimeter of the illuminated zone and crouched. Inside the circle sat a transparent glass marble. I pressed a gloved finger against its curved surface, rolling it three inches forward until it aligned precisely with the shadow cast by a metal ruler. The optical refraction created a miniature flare across the grain. The desk surface is stable, level, and well-suited for night observation.