Everyone in the little cabin held his breath. Dramatically, Professor Bettenridge took a metal tuning fork and struck it sharply against the crystal ball in the center of his machine.
“It will take a moment for the sound to reach the lake,” he said softly. “But only a moment. Watch closely.”
All persons in the room crowded to the door and the windows. Suddenly a huge burst of flame appeared on the lake, fanning out on the surface of the water. A moment later came the dull boom of a terrific explosion.
CHAPTER
16
SUSPICION
Everyone who witnessed the spectacular demonstration was awed by the sight of the flames rising above the lake. As they died away, Professor Bettenridge, strutting a bit, walked back to his machine and covered it with the canvas hood.
“Now are you satisfied?” he inquired triumphantly. “Is there anyone here who doubts the remarkable possibilities of my invention?”
“It was a fine demonstration! Magnificent!” approved Mr. Johnson, fairly beside himself with excitement. “I am convinced of the machine’s worth and if we can agree upon terms I will write you a check tonight.”
Professor Bettenridge’s expression did not change, but the brief glance he flashed his wife was not lost upon Penny or Salt.
“You understand, of course,” he said smoothly, “that the Navy probably will insist upon ultimate purchase of the machine even if I relinquish ownership?”
“Certainly,” agreed Mr. Johnson. “I should expect to make such a sale. The machine would have no practical use except in warfare.”