And here, the first of the construction operators sent forward, Alex had been two days established in the “telegraph-car.”

As he had anticipated, Alex was enjoying the experience hugely. It was every bit as good as camping out, he had declared over the wire to Jack—having for an office a table at one end of the old freight-car, sleeping in a shelf-like bunk at the other end, and eating in the rough-and-ready diner with the inspectors, foremen, time-keepers and clerks who shared the telegraph-car with him. As well, the work going on about him was a constant source of interest during Alex’s spare moments.

On this, the second day, Alex had been particularly interested in the newly-arrived track-laying machine—which did not actually lay track at all, but by means of roller-bottomed chutes fed out a stream of rails and ties to the men ahead of it. After supper, the wire being silent, Alex made his way amid several trains of track-material already filling completed sidings, for a closer view of the big machine.

There proved to be less to see than he had expected; and having climbed aboard the pilot-car and examined the engine, Alex ascended the tower from which a brakeman controlled the movements of the train.

On his right lay a string of flats piled high with timbers for bridges and culverts. Glancing along them, Alex was surprised to see a man’s head cautiously emerge from an opening in the lumber on one of the cars, and quickly disappear on discovering him. A moment after he had a fleeting glimpse of the intruder running low along the side of the train toward the rear.

“Only a hobo,” Alex decided on second thought. For numbers of tramps had come through on the material-trains. And presently Alex returned to the telegraph-car.

Shortly after midnight the young operator was awakened by someone running through the car and shouting for Construction Superintendent Finnan. When he caught the word “Fire!” he scrambled into his clothes and leaped to the floor, and out.

Over the tops of the cars in the direction of the track-machine was a dancing glare.

In alarm Alex joined the stream of men dropping to the ground all along the boarding-cars. Dodging through the intervening trains, he brought up with an expression of relief beside, not the track-machine, but a car of bridge material.

Fanned by a brisk wind, flames were spouting from amid the timbers at several points. Already men were pitching the burning beams over the side, however; and finding a shovel, Alex joined those who were smothering them with sand.