shaft, beyond the bulkhead, some thirty minutes before this juncture, a candle had guttered in its stick, left carelessly thrust into the wall by Marrophat's lieutenant, and, guttering, had dropped a flaming wick into the little heap of bone-dry débris which blazed up against the timbering that upheld the walls of the tunnel. This timbering caught fire without delay, and in a space of time incredibly brief the flames were spreading right and left.
As Alan said a mute farewell to Rose and Barcus the fire spread out in the bottom of the shaft and invaded the powder-room. Alan had guessed aright at Marrophat's design: the keg of blasting-powder was less than an eighth full, its explosion could not possibly have effected the cave-in Alan had at first feared.
But what Marrophat had overlooked was the proximity to the keg of several sticks of dynamite, masked by a film of earth that had fallen from the crumbling walls. When the blazing fuse dropped sparks into the blasting-powder this last exploded right willingly, and the dynamite took its cue without the least delay.
The resultant detonation was terrific. The bulk-head was crushed in like an eggshell barrier, and the released flood streamed out and spread swiftly to the farthest recesses of the burning tunnel. Dense clouds of steam filled that place of terror as the fires were extinguished.
