ing down the mountain side with a speed that was
momentarily increasing, and without a chance of retarding it!

The young inventor at that moment of peril, knew no more what to do to
avert disaster than Ned Newton himself.

It flashed across his mind, however, that others beside themselves were
in peril because of this accident. The fast express from the East that
should pass Half Way at four-thirteen, might already be climbing the
hill from Hammon. Hammon, at the foot of the grade, was twenty-five
miles away. Nor was the track straight.

If the operator at Half Way did not see the runaway locomotive and
telephone the danger to the foot of the grade, when the Hercules 0001
came tearing down the track it might ram something in the Hammon yard,
if it did not actually collide with the approaching westbound express.

Such an emergency as this is likely either to numb the brains of those
entangled in the peril or excite them to increased activity. Ned Newton
was apparently stunned by the catastrophe. Tom's brain never worked
more clearly.

He seized the siren lever and set it at full, so that the blast called
up continuous echoes in the forest as the locomotive plunged down the
incline. He ran to the door again, on the side where Half Way station
lay, and hung out to signal the operator who had so recently given him
right of way on this stretch of mountain road.

"We're going to smash! We're going to smash!" groaned Ned Newton.

Tom read these words on his chum's lips, rather than heard them, for
the roar of the descending locomotive drowned every other sound. Tom
waved an encouraging hand, but did not reply audibly.

Meanwhile his brain was working as fast as ever it had. He had
instantly comprehended all the danger of the situation. But in addition
he appreciated the fact that such an accident as this might happen at
any time to this or any other locomotive he might build.

Automatic brakes were all right. If there had been a good drag of cars
behind the Hercules 0001, on which the compressed air brakes might have
been set, the present manifest peril might have been obliterated. The
brakes on the cars would have stopped the whole train.

But to halt this huge monster when alone, on the grade, was another
matter. Once the locomotive brake lever was jammed, as in this case,
there was no help for the huge machine. It had to ride to the foot of
the grade--if it did not chance to hit something on the way!

And with