“Anything? Any answer?” asked Beatrice, laying a hand upon his shoulder--a hand that trembled.
He shook his head in negation. Again he switched the roaring current on; again he hurled out into ether his cry of warning and distress, of hope, of invitation--the last lone call of man to man--of the last New Yorker to any other human being who, by the merest chance, might possibly hear him in the wreck of other cities, other lands. “S. O. S.!” crackled the green flame. “S. O. S.! S. O. S.!--”
Thus came night, fully, as they waited, as they called and listened; as, together there in that tiny structure on the roof of the tremendous ruin, they swept the heavens and the earth with their wild call--in vain.
Half an hour passed and still the engineer, grim as death, whirled the chained lightnings out and away.
“Nothing yet?” cried Beatrice at last, unable to keep silence any longer. “Are you quite sure you can't--”
The question was not finished.
For suddenly, far down below them, as though buried in the entrails of the earth, shuddered a stifled, booming roar.
Through every rotten beam and fiber the vast wreck of the building vibrated. Some wall or other, somewhere, crumbled and went crashing down with a long, deep droning thunder that ended in a sliding diminuendo of noise.
“The boiler!” shouted Stern.
Off he flung the head-piece. He leaped up; he seized the girl.