In a very short time he had chipped off enough of the quartz to reveal a curious yellow vein which seemed to extend an indefinite distance into the ledge.

The professor appeared excited.

Seeing this, Frank put his helmet close to his and shouted:

“Well, Von Bulow, what do you make of it?”

“Gold!” shouted the excited scientist.

Frank was astounded.

“Gold?” he repeated.

“Yes.”

“A submarine gold mine?”

“Exactly.”