At certain intervals he fancied he could hear rumbling noises in the distance, dull and threatening like the mutter-ings of thunder before a storm. There surely must be a storm raging down below at the foot of the mountains. He got up and went out to see.
The moon was rising. The atmosphere was pure and calm. Not a cloud visible either above or below. Here and there was a passing reflection from the flames of Antuco, but neither storm nor lightning, and myriads of bright stars studded the zenith. Still the rumbling noises continued. They seemed to meet together and cross the chain of the Andes. Glenarvan returned to the CASUCHA more uneasy than ever, questioning within himself as to the connection between these sounds and the flight of the guanacos. He looked at his watch and found the time was about two in the morning. As he had no certainty, however, of any immediate danger, he did not wake his companions, who were sleeping soundly after their fatigue, and after a little dozed off himself, and slumbered heavily for some hours.
All of a sudden a violent crash made him start to his feet. A deafening noise fell on his ear like the roar of artillery. He felt the ground giving way beneath him, and the CASUCHA rocked to and fro, and opened.
He shouted to his companions, but they were already awake, and tumbling pell-mell over each other. They were being rapidly dragged down a steep declivity. Day dawned and revealed a terrible scene. The form of the mountains changed in an instant. Cones were cut off. Tottering peaks disappeared as if some trap had opened at their base. Owing to a peculiar phenomenon of the Cordilleras, an enormous mass, many miles in extent, had been displaced entirely, and was speeding down toward the plain.
"An earthquake!" exclaimed Paganel. He was not mistaken. It was one of those cataclysms frequent in Chili, and in this very region where Copiapo had been twice destroyed, and Santiago four times laid in ruins in fourteen years. This region of the globe is so underlaid with volcanic fires and the volcanoes of recent origin are such insufficient safety valves for the subterranean vapors, that shocks are of frequent occurrence, and are called by the people TREMBLORES.
The plateau to which the seven men were clinging, holding on by tufts of lichen, and giddy and terrified in the extreme, was rushing down the declivity with the swiftness of an express, at the rate of fifty miles an hour. Not a cry was possible, nor an attempt to get off or stop. They could not even have heard themselves speak. The internal rumblings, the crash of the avalanches, the fall of masses of granite and basalt, and the whirlwind of pulverized snow, made all communication impossible. Sometimes they went perfectly smoothly along without jolts or jerks, and sometimes on the contrary, the plateau would reel and roll like a ship in a storm, coasting past abysses in which fragments of the mountain were falling, tearing up trees by the roots, and leveling, as if with the keen edge of an immense scythe, every projection of the declivity.
How long this indescribable descent would last, no one could calculate, nor what it would end in ultimately. None of the party knew whether the rest were still alive, whether one or another were not already lying in the depths of some abyss. Almost breathless with the swift motion, frozen with the cold air, which pierced them through, and blinded with the whirling snow, they gasped for breath, and became exhausted and nearly inanimate, only retaining their hold of the rocks by a powerful instinct of self-preservation. Suddenly a tremendous shock pitched them right off, and sent them rolling to the very foot of the mountain. The plateau had stopped.
For some minutes no one stirred. At last one of the party picked himself up, and stood on his feet, stunned by the shock, but still firm on his legs. This was the Major. He shook off the blinding snow and looked around him. His companions lay in a close circle like the shots from a gun that has just been discharged, piled one on top of another.