"Well, there's no danger, that's sure," said Bert. "It's a queer place to be lost in--a subway station. I was never in one before, but if we stay here long enough Dad is sure to find us. Here comes somebody now, looking for us, I guess."

A man in a blue suit, carrying a red lantern, and with white numbers on either side of his cap, walked toward the four twins.

"Is your name Bobbsey?" he asked.

"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."

Speaking of chewing gum made Flossie remember she was thirsty, and after Mr. Bobbsey had thanked the man with the red lantern, and had explained to Freddie that it was used to stop trains in case of an accident, the Bobbsey party went up out of the underground station and into a candy store.

"I know what I'm going to have!" exclaimed Freddie.

"So do I!" cried Flossie.

"Chocolate soda!"

"Yes! And I want plenty of cream on top!"

"Suppose they haven't got any chocolate soda?" remarked Mr. Bobbsey, with a twinkle in his eye.

"Oh, I know they've got chocolate soda," remonstrated his little son.

"They always have chocolate soda at soda fountains! Don't they, Flossie?"

"Of course they do! I don't think it would be a real soda fountain if they didn't have chocolate soda," replied the little girl.

"I think I'm going to have an orange phosphate," said Bert.

"And that is just what I am going to have too," added Nan.

"Phosphate!" cried Freddie in wonder. "I wouldn't drink any phosphate!

That's what they make matches of."

"Oh, just hear that!" cried Bert, laughing. "Freddie thinks they make matches of phosphate."

"They do, too!" answered the little boy.

"You are thinking of phosphorus, Freddie," explained Mr. Bobbsey. "That is different, and it is poisonous." Then the drinks were ordered and quickly served.

"And now I want to go to see the big fish!" said Freddie, sipping the last drops of his sweet drink. "Are there any animals in the 'quarium, Daddy?"

"Well, there aren't any lions or tigers," answered Mr. Bobbsey. "We'll go to see them later in Bronx Park. But, of course, fish are animals. It won't take me long to run into City Hall and see my friend. Then we'll go to the Aquarium."

Left on the top steps of the City Hall building, this time the Bobbsey twins were found safely there when their father came out, and a little later they were on their way to Battery Park in a Broadway street car, that ran on the ground.

"We've ridden under the ground in the subway, over the ground in the elevated and now we're riding _on_ the ground," said Nan. "New York is a funny place!"

The Aquarium, as those of you know who have seen it, is in the round, brown stone building, on a point of land almost the very end of the island of Manhattan. It is where the North and East rivers come together to form New York Bay, and, years ago, this building was where the immigrants, or people who came to the United States from other countries, were kept for a while until they could be sent out West, or down South, or wherever they wanted to go.

Now it is a place where many fish, big, little, ugly and beautiful, are shown in tanks of water so the boys and girls can see what strange things are in the ocean, rivers and lakes of this world.

Led by Mr. Bobbsey, Bert and Nan, with Flossie and Freddie trailing on behind, walked around the big building, looking in the gla.s.s tanks wherein swam the fish.

"What's over there?" asked Freddie, pointing to where a crowd of people were standing near some pools in the middle of the floor.

"Oh, different big fish--a sea lion, alligators and turtles," said Mr.

Bobbsey.

"Let's look at the sea lion!" called Flossie.

"I want to see a swimming turtle," said Freddie. "I had a mud turtle once, but he went away."

"You shall see everything," promised Mr. Bobbsey.

They went over to the pool, where a number of large alligators, and one crocodile, were lying in or out of the water. Some were lazily swimming about, and the crocodile was asleep out on the stone ledge, with his big mouth wide open.

"He's waiting for some one to come along and feed him," said Bert.

"I guess he'd eat a lot," laughed Freddie, looking at the rows of big teeth in the crocodile's mouth.

They pa.s.sed on to the pool of the sea lion. That sleek, brown animal was swimming about like a big fish, now and then stopping under one of the pipes where the water ran into his pool, and holding his mouth under the little stream as though taking a drink. Now and then he barked like a dog.

Around the stone ledge, or wall of the pool, was a wire grating, and near the floor was a sort of pipe running all around, so the smaller children could step up on this to look in--something which the big folk did not have to do.

"Be careful!" cried Nan, as Flossie leaned well over the edge to get a better look at the sea lion. "You might fall in."

"She could get a ride on his back if she did," said Freddie.

"Well, I'm not going to!" exclaimed Flossie, drawing back, a little frightened, as the seal splashed the water right under her, some drops going in her face.

They watched the seal for a while, went over to the other tanks, where some sturgeon and other big fish swam about, and then Freddie called:

"I want to see the big turtles! Where are they?"

"Over here," said Mr. Bobbsey, leading the way toward the south end of the building near the tank, where the green moray--a sort of big eel--was lying half in and half out of a piece of sewer pipe put in his tank to make him feel more at home. "There are the big turtles," and Mr.

Bobbsey lifted Flossie up over the rail so she could look down more easily.