dren_! That's what I
can't stand--the little folks getting hurt and getting killed, when just
a bit of common sense would save them! Oh, if their fathers and mothers
had any idea--"

The big engineer choked up for a moment. "Even on the trains," he
added, "when they're safe inside the cars, they get hurt. I'm not the
only one that worries on my run--ask the conductor. He'll tell you how
they run up and down the aisle, till a sudden jar of the brakes throws
'em against a seat iron or into the other passengers. They get out into
the vestibules, which is against the rules, and when the train takes a
sudden curve they get smashed up."

Three minutes later he slowed down for the twins to watch the fast mail
thunder past. It was near a village crossing, and a little group of boys
stood waiting. As No. 777 came to a stop, the twins saw that most of the
boys had stones in their hands.

On came the fast mail, tearing past the little village as if it were not
even on the map. The mail cars--the smoker--the long rows of glass
windows, a head beside each--

Smash! The flying splinters of glass told of one stone that had found
its mark. The boys ran like scared cats around the corner into a lumber
yard.

"Little cowards!" The fireman glared angrily after them. "They may have
killed somebody on that train--_they_ don't know!"

"Rub your buttons!" whispered Sure Pop, whose eyes were still fixed on
the fast mail, now disappearing in a cloud of smoke and dust.

Bob and Betty rubbed. At their first touch of the magic buttons the
disappearing train took on a queer, unreal look, like a film at the
"movies."

They seemed to be inside one of the cars. They seemed to be watching a
sweet-faced old lady--somebody's grandmother--snowy haired, kind,
gentle, not used to traveling, as even the twins could see. She kept
looking first at the time-table and then at an old key-winding silver
watch she wore on a quaint little chain around her neck.

Her lips were moving, smiling. "Only two stops more," she seemed to be
saying, "and then I shall see little Jim." She took a kodak picture out
of her handbag and looked at it long and lovingly. She glanced out of
the window and saw a group of boys standing by the village crossing "to
watch the fast mail go through." She liked boys. She smiled at them--she
did not see the stones in their hands.

Smash! The other passengers sprang to their feet as one of the stones,
thrown at random, shivered the