Thanksgiving Day came, bringing a little vacation period, and after church in the morning, the Bobbsey twins went home to eat roast turkey and cranberry sauce.  Then they went out to play with some of their boy and girl friends, having lots of fun in the barn and yard.

“But don’t slide any more hay down on Flossie and Freddie!” begged Mrs. Bobbsey.

“We won’t!” promised Bert and Nan, and they kept their word.

It was about a week after Thanksgiving, and Bert and Nan were on their way home from school one day, when, as they passed a red brick house on the street next to theirs, they saw, standing on the porch, a pleasant-faced, elderly lady who was looking up and down the avenue.

“That’s Miss Pompret,” said Nan to Bert.  “I heard mother say she was very rich.”

“Is she?” asked Bert.  “She looks kind of funny.”

“That’s ’cause she isn’t married,” returned Nan.  “Some folks call her an old maid, but I don’t think she’s very old, even if her hair is white.  Her face looks nice.”

“Yes, but she looks kind of worried now,” said Bert.  “That’s the way mother looks when she’s worried.”

They were in front of the house now, and could see Miss Pompret quite plainly.  Certainly the elderly lady did look as though something troubled her.

“Good afternoon, Miss Pompret!” called Nan, as she was about to pass by.  Bert took off his cap and bowed.

“Oh, you’re half of the Bobbsey twins, aren’t you?” asked Miss Pompret, with a smile.  “I often see you go past.  I only wish you were a little bigger.”

“Bigger?  Why?” asked Bert, in some surprise.

“Why, then,” explained Miss Pompret, “you might take this letter to the post-office for me.  It’s very important, and I want it to go out on this mail, but I can’t go to the post-office myself.  If you Bobbsey twins were bigger I should ask you to take it.  Tell me, is the other set of twins larger than you two?”

“No’m; they’re smaller,” explained Nan.  “Flossie and Freddie are lots littler than we are.”

“But we’re big enough to take the letter to the post-office for you, Miss Pompret,” said Bert.  He had often heard his father and mother speak of this neighbor, and the kindnesses she had done.

“Are you sure you are big enough to go to the post-office for me?” asked Miss Pompret.

“We often go for daddy and mother,” said Nan.

“Well, then, if you think your mother wouldn’t mind, I would like, very much, to have you go,” said Miss Pompret.  “The letter is very important, but I can not take it myself, as I have company, and I have no one, just now, who can leave.  I thought I might see some large boy on the street, but—­”

“I’m big enough!” exclaimed Bert.

“Yes, I believe you are!” agreed the elderly lady, looking at him through her glasses.  “Well, I shall be very thankful to you and your sister if you will mail the letter for me.  And, on your way back, stop and let me know that you dropped it in the post-office all right.”