“No, the sun is shining,” said the twins’ mother.

“But I’m sure that is thunder,” went on Mrs. Morris.

There was a rumbling sound down the road, and there seemed to be some excitement there, for a number of children who had started toward the ice cream pavilion turned back.

“I wonder what it is,” mused Mrs. Bobbsey.  “I hope no ‘almost’ accidents are going to happen.”

“I’ll go see what it is,” offered Bert.

He ran down the road, was gone a little while, and came back, his eyes shining with eagerness.

“Oh, it’s a big merry-go-round!” he cried.

“A merry-go-round?” repeated his mother, busy at the ice cream.

“Yes, a man has a big merry-go-round in pieces on three or four big wagons,” Bert reported.  “Something’s the matter with the engine—­it runs by a steam engine, and something’s the matter!”

“Bert, go call your father,” said Mrs. Bobbsey, for her husband had gone to the far side of the grove to get another ice cream tub from the truck on which they were brought to the picnic.  “We don’t want any strange men setting up a merry-go-round here.  Call your father!”

CHAPTER IV

A MISSING COAT

Mr. Bobbsey came hurrying over to the ice cream pavilion, with Bert almost running beside him to keep up with his father.

“What’s all this, Mother?” asked Mr. Bobbsey, who, with his coat off and his sleeves rolled up, was working hard to help the ladies at the Sunday school picnic.  “What’s all this about a merry-go-round coming here?”

“I don’t know that it is coming here,” answered Mrs. Bobbsey, with a smile.  “But some sort of affair is thundering along the road.  You can see the crowd of children near it.  A merry-go-round some one said.  I thought perhaps some men owning one of those traveling affairs had heard about our picnic and had come here to set up a machine.  We don’t want anything like that.”

“No,” agreed Mr. Bobbsey with a smile.  “We don’t.  I’ll go see about it,” and off he went, followed by Bert.  Nan, with Flossie and Freddie, had already joined the group of children down near the road that extended along one edge of the picnic grove.

As Bert and his father neared the place, a loud, hissing sound was heard and a white cloud of steam shot into the air, while the little ones screamed and scattered.

“What’s that?” cried Bert.

“I hope those youngsters don’t go too near!” murmured Mr. Bobbsey.  “The safety valve of his steam engine is blowing off.  He’s got too much pressure on.  It may be dangerous,” and Mr. Bobbsey broke into a run, which Bert imitated as well as he could with his shorter legs.

However, there was no great danger.  As Mr. Bobbsey had said, the safety valve of a steam engine, on one of the trucks which carried the merry-go-round outfit, was blowing off, and a short, stout man, with a very red face, and a lanky boy, wearing ragged clothes, were working about the engine.