Gramont came to the bayou and began searching his way along the thick and high fringe of bushes and saplings that girded the water's edge. Presently he came upon the ruined evidences of what had once been a small boat shed. Not far from this he found the dock referred to in the letter; nothing was left of it except a few spiles protruding from the surface of the water. But he had no need to look farther. Directly before him, he saw that which he was seeking.
A dozen feet out from shore the water was rising and falling in a continuous dome or fountain of highly charged bubbles that rose a foot above the surface. Gramont stared at it, motionless. He watched it for a space—then, abruptly, he started. It was a violent start, a start of sheer amazement and incredulity.
He leaned forward, staring no longer at the gas dome, but at the water closer inshore. For a moment he thought that his senses had deceived him, then he saw that the thing was there indeed, there beyond any doubt—a very faint trace of iridescent light that played over the surface of the water.
"It can't be possible!" he muttered, bending
