But the oval was not perfect; at my right a screen cut it⁠—a screen that gleamed with fugitive, fleeting luminescences⁠—stretching from the side of our standing place up to the tip of the chamber; slightly convex and crisscrossed by millions of fine lines like those upon a spectroscopic plate, but with this difference⁠—that within each line I sensed the presence of multitudes of finer lines, dwindling into infinitude, ultramicroscopic, traced by some instrument compared to whose delicacy our finest tool would be as a crowbar to the needle of a micrometer.

A foot or two from it stood something like the standee of a compass, bearing, like it a cradled dial under whose crystal ran concentric rings of prisoned, lambent vapours, faintly blue. From the edge of the dial jutted a little shelf of crystal, a keyboard, in which were cut eight small cups.

Within these cups the handmaiden placed her tapering fingers. She gazed down upon the disk; pressed a digit⁠—and the screen behind us slipped noiselessly into another angle.