“How could we?” asked Bert.  “If they were there they’d belong to Washington, wouldn’t they, Daddy?”

“Well, I suppose all the things in the house once belonged to him or his friends,” said Mr. Bobbsey.  “But I don’t imagine those two missing pieces of Miss Pompret’s set will be at Mount Vernon, Nan.”

“No, I don’t s’pose so,” sighed the little girl.  “But, oh, I would like to find ’em!”

“And get the hundred dollars reward!” added Bert.

“Don’t think too much of that,” advised their mother.  “Of course it would be nice to find Miss Pompret’s dishes, and do her a favor, but I think it is out of the question after all these years that they have been lost.”

The weather was colder than on the day before, when Flossie and Freddie had been lost, and the sun shone fitfully from behind clouds.

“I think we are going to have a snow storm,” said Mr. Bobbsey, on their way to take the boat for Mt.  Vernon.

“Oh, goodie!” cried Flossie.  “I hope it snows a lot!”

“So do I!” added Freddie.  “Could we send home for our sled if there’s lots of snow, Daddy?” he asked.

“I hardly think it would be worth while,” said his father.  “We are not going to be here much more than a week longer.  And it would be quite a lot of work to get your sleds here and send them home again.  I think you’ll get all the coasting and skating you want when we get back to Lakeport.”

“Anyway, we’re having a nice time while we’re here,” said Nan, with a happy little sigh.

“It’s fun when Freddie and Flossie don’t get lost,” added Bert.  “I’m going to keep watch of ’em this time.”

“I’ll help,” added Nan.  “Oh, here are Billy and Nell!” she called, waving her hand to their new friends.  The Martin children were to go to Mount Vernon with the Bobbsey twins, and they now met them near the place from which the boat started.

“All aboard!” cried Freddie, as they went on the small steamer that was to take them to Mount Vernon.  “All aboard.  I’m the fireman!”

“There aren’t any fires to put out,” said, Nell, teasing the small chap a little.

“Yes, there is—­a fire in the boiler, and it makes steam,” said Freddie, who had often looked in the engine room of steamers.  “But I’m not that kind of fireman.  I put out fires.  I’m going to be a real fireman when I grow up,” he added.

Soon they were comfortably seated on board the boat, which after a bit moved out into the Potomac.  Mr. and Mrs. Bobbsey were talking together.  Nan, Bert, Billy and Nell were watching another boat which was passing, and Flossie was near them.  But Freddie had slipped away, in spite of what Bert had said about going to keep a watchful eye on his small brother.

Suddenly, when the steamer was well out in the river, there was the loud clanging of a bell, and a voice cried: 

“Fire!  Fire!  Fire!”

At once every one on the boat jumped up.  The women looked frightened, while the men seemed uncertain what to do.