"It's Gone!" Cried Ned
A trifle gingerly his chum extended his hand toward the circle of metal. Though Tom had assured him that the little disk was still in place, Ned was unable to repress a start when his finger touched a cool, polished surface which his eyes told him could not be there.
"Say, that's wonderful!" he exclaimed, staring at the invisible substance with awe. "That stuff must be a hundred times more transparent than the finest plate glass!"
His Finger Touched the Cool Surface
"Yes, and more," said Tom. "But that's not the most wonderful feature of the new substance."
"What, then?"
"Well, it's difficult to explain. Even now I know very little about it. I can tell you WHAT it can do, but the WHY is still as much of a mystery as ever. Briefly, this new element, or maybe it's a compound, I'm not sure which, reacts in a very strange manner to light. Let me show you. That'll beat any long-winded theory I could spout."
