A silver sphere swam in vague depths. The surrounding frame of intricate mechanism gave off a soft phosphorescence that strengthened and faded by turns. A young man, robed in gossamer vitri of richest hue, leaned over, watching keenly. His fingers moved controls at the bottom of the machine. The silver sphere leaped upward in the vision plate, swelling like a balloon. Continents and seas were now visible. Then one area swelled over the visor-plate. Gradually a small spot became a city, a strange