“Good luck,” sent Alex, with a sudden catch in his throat, as he realized the danger his chum was so cheerfully running. “God help him!” added the superintendent fervently.

Jack, in the distant tower, took little time to think of the danger himself. Catching up a lantern and lighting it, he was quickly out and down the tower steps, and running for the nearby shed. Fortunately it was unlocked. Darting in, he found a large can of oil. Carrying it out to the main-line track, he returned, and hurriedly dragged forth the yard lamp-man’s rail bicycle—a three-wheeled affair, with the seat and gear of an ordinary bicycle.

Swinging the little car onto the rails, he placed the oil can on the platform between the arms, swung the lantern over the handlebars, mounted, and was off, pedalling with all his might.

As he speedily neared the down-grade of the bridge approach, and the roar of the flood met him in full force, Jack for the first time began to realize the danger of his mission. But with grimly set lips, he refused to think of it, and pedalled ahead determinedly.

He topped the grade, and below him was a solid roof of mist, only the bridge towers showing.

Apprehensively, but without hesitation, he sped downward. The first dampness of the vapor struck him. The next moment he was lost in a blinding wall of white. He could not see the rails.

On he pedalled with bowed head. Suddenly came a roar beneath him. He was over the water.

Jack’s occasional views from the tower had shown him where the bridge was shattered; and for some distance he continued ahead at a good speed. Then judging he was nearing the wrecked portion, he slowed down and went on very slowly, peering before him with straining eyes, and listening sharply for a note in the tumult of water below which might tell of the broken timbers and twisted iron.

It came, a roar of swirling, choking and gurgling. Simultaneously there was a trembling of the rails beneath him.

He was on the shattered span.