Running, even as he cringed, he had upset a glass retort, which had shattered on the concrete floor.

And as he ran, he screamed: "_They're in! They're coming! Quick--the steel vaults! Let me in, there! Let me in!_" The coward was now a maniac with terror, his face perfectly white, writhen with panic, and with staring eyes that gleamed horribly under the greenish vacuum-lights.
"Back, you! Get out!" roared Waldron, raising a fist.

"We--" A sudden belch of flame, outside, split the night with terrible virescence.

The whole steel building trembled and swayed.

Some of its girders buckled; and the east wall, nearest the oxygen-tanks, caved inward as a mass of many tons was hurled against it.
A stunning concussion flung all three men to the floor; and, as they fell, a withering heat-wave quivered through the place.
"The oxygen-tanks!" gasped Flint.