Gradually the light grew brighter, till, as they suddenly rounded a cliff, a grand sight burst upon their view. They found themselves in a vast dome-shaped cavern, thousands of yards in diameter and height. And almost in the centre of the floor, from a red and purple mound of cooling lava, leapt a white stream of molten matter from the floor to the dome. And in the black dome, where the lava turned to molten spray, hung countless stalactites of every color known to the artistic eye. And from the foot of the fountain ran a tortuous rivulet that lighted the walls and roof of a narrow chamber that extended for miles down toward the bowels of the earth.
Branasko was delighted.
"The king does not know of this," he declared, "else he would make it accessible to his people, and call it one of the wonders of Alpha. By accidentally sinking into the pit we have discovered it.
But," he concluded, "we must at once try to find some way out other than that by which we came."They turned from the beautiful fountain, and, holding to each other's hands, and aided by the light behind them, they stumbled laboriously through the semi-darkness. Branasko's ears were very acute. He paused to listen.
"Hark ye!" he cautioned.
The combined roar of the pit and the fountain of lava had sunk to a low murmur, but ahead of them they now heard a rushing sound like a distant tornado.
"Come on," said the Alphian, and he drew his companion after him with an eagerness the American was slow to understand. The light in the cavern gradually grew brighter. By a circuitous route they were again approaching the pit of fire, though it was still hidden from sight.
Finally they reached a point where the wind was blowing stiffly, and further on a volume of cold spray suddenly dashed upon them and wet them to the skin. And when their eyes had become accustomed to the rolling mist, they saw a great lake, and pouring into it from high above was a mighty waterfall.
"Mercy!" ejaculated the Alphian, in great alarm. "If this is salt water we are lost. All Alpha will come to an end!""What do you mean?" And Johnston wondered if Branasko's trials and struggle could have turned his brain.
"If it be salt water, then it has broken in from the ocean above Alpha," he explained. "The king has often said that not a drop of the ocean has ever entered the great cavern."Branasko stooped and wet his hand in a little pool at his feet. "Iam almost afraid to taste it," said he, holding his hand near his mouth. "It would settle all our fates." He waited a moment and then touched his fingers to his tongue.
"Salt!" That was all he said for several moments. He folded his arms and looked mutely toward the boiling lake. Presently he raised his eyes to the great hole in the roof, and groaned: "The break is gradually widening. These stones are freshly broken, and the great bowl is filling.""It will fill all Alpha with water and drown every soul in it,"added the terrified American.
"That, however, is not the most immediate danger," said Branasko wisely. "They would first suffocate, and later their bodies would be swallowed up in the stomach of the earth.""What do you mean?"
Branasko shrugged his shoulders. "As soon as this bowl is filled with water, which would not take many hours, it would run over into the lake of fire and produce an explosion that would rend Alpha from end to end.""Who knows, it might turn the whole Atlantic into the centre of the earth, and destroy the entire earth."But Branasko was unable to grasp the full magnitude of the remark, for to him the world was simply a vast cavern lighted by human ingenuity. He fastened a narrow splinter of stone upright in the shallow water at his eet, and, lying down on his stomach with his eyes close to it, he studied it for several minutes. When he got up, a desperate gleam was in his dark eyes.
"It is rising fast," he said. "We must attempt to get to the capitol and warn the king. It is possible that he may be able to stop the opening. The only thing left to us is to try our machine again."Johnston found it hard to keep pace with him as he bounded out of the mist and on toward the faint glow ahead. Reaching the flying machine Branasko entered it and turned on a small electric light.
"Ah," he grunted with satisfaction, "I have found a light. I can now see what is the matter with it."Johnston stood outside and heard him hammering on the metal parts in the car, and became so absorbed in thinking of the peril of their position that he was startled when Branasko cried out to him:--"All right. I think we can make it do; a pin has lost out, but perhaps I can hold the piece in place with my foot. If only we can stand the heat of the pit long enough to rise above it, we may escape."Johnston followed him into the car. Branasko seated himself firmly and gave the wheel a little turn. Slowly the machine rose. "See!"cried Branasko, "it is under control. "We must not be too hasty.
Now for the pit!"
The heart of the American was in his mouth as the long black wings waved up and down and the air-ship, like some live thing, shuddered and swept gracefully out of the mouth of the cave into the glare and heat of the pit.
"Hold your breath!" yelled Branasko, and he bent lower into the car to escape the shower of hot ashes that was falling about them.
Far out over the lake in a straight line they glided, and there came to a sudden halt. Johnston's eyes were glued on his companion's face. Branasko sat doubled up, every muscle drawn, his eyes bulging from their sockets. Would he be strong enough? To Johnston everything seemed in a whirl. The walls of the pit were rising around them.
