"Yes; but how did you know?" was Bert's question.

"Your father sent me to look for you. He guessed you must have wandered
away, and he thought it best to stay where he told you to wait, and let
one of us find you. A lot of men are hunting up and down the different
platforms for you."

"Well, I'm glad you found us!" sighed Nan. "We didn't know what to do."

"Just come with me," said the subway guard. "I'll take you to your
father," and he did, leading the children down a long platform and over a
sort of bridge, then down a flight of steps. Though they did not know it,
the twins had wandered quite a distance from the place Mr. Bobbsey had
left them.

The subway station was a rambling place, with several doors to go in by
and come out of, a number of platforms and stairways, and wiser persons
than four small children could easily become confused there.

When Mr. Bobbsey came back, after buying his magazine, and could not find
his children, he guessed what had happened, and wisely asked a guard to
make a search, instead of doing it himself.

"For I don't come to New York often enough to be sure of finding my way
around in all the odd nooks and corners," said the lumber merchant.

"And it wasn't a circus poster at all!" said Freddie, after Flossie had
told what had caused her to wander away. "It was only about chewing gum."