Telegraphic communication having been cut off by the astute Bings, a fierce attack was made on the mine. The assailants swarmed up the sides of the canyon, and attempted to break in through the foundation of the buildings. But the masonry was stronger than they had anticipated, and the attack failed. Sharp-shooters then climbed the neighboring heights, and kept up an incessant peppering of the walls with conical bullets driven at four thousand feet per second. No reply came from the gloomy structure. The huge column of black smoke rose uninterruptedly into the sky, and the noise of the great engine never ceased for an instant. The mob gathered closer on all sides and redoubled the fire of the rifles, to which was now added the belching of several machine-guns. Ragged holes began to appear in the walls, and at the sight of these the assailants yelled with delight. It was evident that, the mill could not long withstand so destructive a bombardment. If the besiegers had possessed artillery they would have knocked the buildings into splinters within twenty minutes. As it was, they would need a whole day to win their victory. Suddenly it became evident that the besieged were about to take a hand in the fight. Thus far they had not shown themselves or fired a shot, but now a movement was perceived on the roof, and the projecting arms of some kind of machinery became visible. Many marksmen concentrated their fire upon the mysterious objects, but apparently with little effect. Bings, mounted on a rock, so as to command a clear view of the field, was on the point, of ordering a party to rush forward with axes and beat down the formidable doors, when there came a blinding flash from the roof, something swished through the air, and a gust of heat met the assailants in the face. Bings dropped dead from his perch, and then, as if the scythe of the Destroyer had swung downward, and to right and left in quick succession, the close-packed mob was levelled, rank after rank, until the few survivors crept behind rocks for refuge. Instantly the atmospheric broom swept up and down the canyon and across the mountain's flanks, and the marksmen fell in bunches like shaken grapes. Nine-tenths of the besiegers were destroyed within ten minutes after the first movement had been noticed on the roof. Those who survived owed their escape to the rocks which concealed them, and they lost no time in crawling off into neighboring chasms, and, as soon as they were beyond eye-shot from the mill, they fled with panic speed. Then the towering form of Dr. Syx appeared at the door. Emerging without sign of fear or excitement, he picked his way among his fallen enemies, and, approaching the military guard-house, undid the fastening and set the imprisoned soldiers free.