Catching it, Chet found that it was nothing but a glass disk.

A thin glass disk with a perfectly polished accurate flat form was placed on a heavy metal pan.

The image was kept clear by a glass disk spinning in front of the lens.

Usually a glass disk is pressed first, and this is used to then make the metal die.

Cain's voice was recorded optically onto the glass disks in a similar way to a film soundtrack.

Trap slipped the little glass disk into his pouch so it would not get lost again in the clutter.

"I had forgotten about this," he said, inspecting the small, gray-green glass disk.

One of the huge glass disks broke during shipping, and making a replacement was delayed.

It slides slowly back and forth, its shadow moving across the glass disk, suggesting lunar phases.

Jari Harcuba cut the realistic details of the profile into a clear glass disk.