"Right!" replied Arcot, "but we're going to give them a little demonstration of power!"
The Ancient Mariner leaped suddenly upward with a speed that defied the eyes of the men at the rays of the enemy ships. Then, as they turned to follow the sudden motion of the ship—it was not there!
The Ancient Mariner had vanished!
Morey was startled for an instant as the ship and his companions disappeared around him, then he realized what had happened. Arcot had used the invisibility apparatus!
Arcot turned and raced swiftly far off to one side, behind the strange ships, and hovered over the great cliff that made the edge of the cleft that was the river bed. Then he snapped the ship into full visibility.
Wade and Fuller had recovered by now, and Arcot started barking out orders. "Wade—Fuller—take the molecular ray, Wade, and tear down that cliff—throw it down into the valley. Fuller, turn the heat beams on with all the power you can get and burn that refuse he tears down into a heap of molten lava!
"I'm going to show them what we can do! And, Wade—after Fuller gets it melted down, throw the molten lava high in the air!"
From the ship, a long pencil of rays, faintly violet from the air they ionized, reached out and touched the cliff. In an instant, it had torn down a vast mass of the solid rock, which came raining down into the valley with a roaring thunder and threw the dirt of the valley into the air like splashed mud.
Then the violet ray died, and two rays of blinding brilliance reached out. The rock was suddenly smoking, steaming. Then it became red, dull at first, then brighter and brighter. Suddenly it collapsed into a great pool of white-hot lava, flowing like water under the influence of the beams from the ship.
Again the pale violet of the molecular beams touched the rock—which was now bubbling lava. In an instant, the great mass of flaming incandescent rock was flying like a glowing meteor, up into the air. It shot up with terrific speed, broke up in mid-air, and fell back as a rain of red-hot stone.