"Well, how would you like to go and see some live fish?" asked Mr. Bobbsey. "That ought to satisfy all of you, and Nan can see some stores on the way to the Aquarium. I have to go downtown in New York," he said to his wife, "and I can take the children to the Aquarium at the Battery as well as not."
"All right," said Mrs. Bobbsey. "If you'll do that I'll stay here and rest. Afternoon will do for me to go out. Now mind, Flossie and Freddie, don't get lost again!"
The small twins promised they would not and soon all four were on their way downtown with their father. This time they went in the subway, or underground road, which, as Freddie said, was like one big, long tunnel.
"We'll get out at the Brooklyn Bridge or City Hall Park," said Mr. Bobbsey. "I have to see a man in the City Hall, and from there we can walk to the Battery, as it is a nice day. Or we can ride, if you get too tired."
The children were sure they would not get too tired, and a little later they all got out at the subway station at Brooklyn Bridge.
There were many persons hurrying to and fro, trains coming in and going out, and lights all over, making the children think it was night, though it was in the morning.
"Wait here just a minute," said Mr. Bobbsey, showing the twins a less crowded place where they could stay. "I want to get a magazine over at the news-stand," he added.
The magazine he wanted had been put away under a pile of papers, and as the boy was getting it out Flossie caught sight, down the platform, of a man pasting up on the advertising boards in the underground station, some new posters.
"Oh, maybe it's signs about a circus, Freddie!" cried the little girl "Come on and watch!"
Freddie was always ready to go, and he had darted off after his sister down the long platform before Bert and Nan saw them. When the two older children missed the younger twins they looked hurriedly about for them.