Engine stopped at the first station for a drink of water and a
mouthful of coal, and then it flew ahead. There was a kind old
locomotive at Omaha that tried to find out where it belonged, and what
its mother's name was, but the Pony Engine was so bewildered it couldn't
tell. And the Express kept gaining on it. On the plains it was chased by
a pack of prairie wolves, but it left them far behind; and the antelopes
were scared half to death. But the worst of it was when the nightmare
got after it."

"The nightmare? Goodness!" said the boy.

"I've had the nightmare," said the little girl.

"Oh yes, a mere human nightmare," said the papa. "But a locomotive
nightmare is a very different thing."

"Why, what's it like?" asked the boy. The little girl was almost afraid
to ask.

"Well, it has only one leg, to begin with."

"Pshaw!"

"Wheel, I mean. And it has four cow-catchers, and four head-lights, and
two boilers, and eight whistles, and it just goes whirling and
screeching along. Of course it wobbles awfully; and as it's only got one
wheel, it has to keep skipping from one track to the other."

"I should think it would run on the cross-ties," said the boy.

"Oh, very well, then!" said the papa. "If you know so much more about it
than I do! Who's telling this story, anyway? Now I shall have to go back
to the beginning. Once there was a little Pony En--"

They both put their hands over his mouth, and just fairly begged him to
go on, and at last he did. "Well, it got away from the nightmare about
morning, but not till the nightmare had bitten a large piece out of its
tender, and then it braced up for the home-stretch. It thought that if
it could once beat the Express to the Sierras, it could keep the start
the rest of the way, for it could get over the mountains quicker than
the Express could, and it might be in San Francisco before the Express
got to Sacramento. The Express kept gaining on it. But it just zipped
along the upper edge of Kansas and the lower edge of Nebraska, and on
through Colorado and Utah and Nevada, and when it got to the Sierras it
just stooped a little, and went over them like a goat; it did, truly;
just doubled up its fore wheels under it, and jumped. And the Express
kept gaining on it. By this time it couldn't say 'Pacific Express' any
more, and it didn't try. It just said 'Express! Express!' and then
''Press! 'Press!' and then ''Ess! 'Ess!' and pretty soon only ''Ss!
'Ss!' And the Express kept