"Any obstruction?" shot out his agile companion, springing to the
fireman's seat, sticking his head out of the window and staring ahead.
"Whew! we're going to hit."

The speaker saw what Ralph also beheld. Dimly outlined directly in
their path was a flat car, and above it, skeletonized against the
fading sunset sky, was the framework of a derrick. A repair or
construction gondola car was straight ahead of No. 999.

They seemed to be approaching it swiftly and irresistibly. The wheels
slid now, fairly locked, there was a marked ease-down, but Ralph saw
plainly that, great or small, a collision was inevitable.

"Say, that fireman of yours!" shouted young Clark--"there he goes."

The locomotive was fairly upon the obstruction now. Ralph stuck to the
lever, setting his lips firmly, a little pale, his muscles twitching
slightly under the stress of excitement and suspense.

"Zing!" remarked the cool comrade of the young engineer--"we're
there!"

At that moment a flying form shot from the running board of the
locomotive. Lemuel Fogg had jumped.

CHAPTER III

ONE OF THE RULES

Locomotive No. 999 landed against the bumper of the gondola car with a
sharp shock. However, there was no crash of consequence. The headlight
radiance now flooded fully the obstruction. Young Clark suddenly
shouted:

"Look out!"

The quick-witted, keen-eyed special passenger was certainly getting
railroad training so coveted by his magnate father. He saw the fireman
shoot through the air in his frightened jump for safety. Lemuel Fogg
landed in a muddy ditch at the side of the tracks, up to his knees in
water.

The sharp, warning cry of Marvin Clark was not needed to appraise
Ralph of the danger that threatened. The jar of the collision had
displaced and upset the derrick. Ralph saw it falling slantingly
towards them. He pulled the reverse lever, but could not get action
quick enough to entirely evade the falling derrick. It grazed the
headlight, chopping off one of its metal wings, and striking the
pilot crushed in one side of the front fender rails.

The young engineer gave the signal for backing the train, and kept in
motion. His purpose was to allay any panic on the part of the
passengers, whom he knew must be alarmed by the erratic tactics of the
past few moments. Then after thus traversing about half the distance
back to the main line, he shut off steam and whistled for
instructions.

"Another notch in my education," obs