After breakfast Tom learned me and Jim how to steer, and divided us all up into four-hour watches, turn and turn about; and when his watch was out I took his place, and he got out the professor's papers and pens and wrote a letter home to his aunt Polly, telling her everything that had happened to us, and dated it "IN THE WELKIN, APPROACHING ENGLAND," and folded it together and stuck it fast with a red wafer, and directed it, and wrote above the direction, in big writing, "FROM TOM SAWYER, THE ERRONORT," and said it would stump old Nat Parsons, the postmaster, when it come along in the mail. I says:

"Tom Sawyer, this ain't no welkin, it's a balloon."

"Well, now, who SAID it was a welkin, smarty?"

"You've wrote it on the letter, anyway."

"What of it? That don't mean that the balloon's the welkin."

"Oh, I thought it did. Well, then, what is a welkin?"

I see in a minute he was stuck. He raked and scraped around in his mind, but he couldn't find nothing, so he had to say:

"I don't know, and nobody don't know. It's just a word, and it's a mighty good word, too. There ain't many that lays over it. I don't believe there's ANY that does."

"Shucks!" I says. "But what does it MEAN? -- that's the p'int. "

"I don't know what it means, I tell you. It's a word that people uses for -- for -- well, it's ornamental. They don't put ruffles on a shirt to keep a person warm, do they?"

"Course they don't."

"But they put them ON, don't they?"

"Yes."

"All right, then; that letter I wrote is a shirt, and the welkin's the ruffle on it."

I judged that that would gravel Jim, and it did.

"Now, Mars Tom, it ain't no use to talk like dat; en, moreover, it's sinful. You knows a letter ain't no shirt, en dey ain't no ruffles on it, nuther. Dey ain't no place to put 'em on; you can't put em on, and dey wouldn't stay ef you did."

"Oh DO shut up, and wait till something's started that you know something about."

"Why, Mars Tom, sholy you can't mean to say I don't know about shirts, when, goodness knows, I's toted home de washin' ever sence --"

"I tell you, this hasn't got anything to do with shirts. I only --"

"Why, Mars Tom, you said yo'self dat a letter --"

"Do you want to drive me crazy? Keep still. I only used it as a metaphor."

That word kinder bricked us up for a minute. Then Jim says -- rather timid, because he see Tom was getting pretty tetchy:

"Mars Tom, what is a metaphor?"

"A metaphor's a -- well, it's a -- a -- a metaphor's an illustration." He see THAT didn't git home, so he tried again. "When I say birds of a feather flocks together, it's a metaphorical way of saying --"

"But dey DON'T, Mars Tom. No, sir, 'deed dey don't. Dey ain't no feathers dat's more alike den a bluebird en a jaybird, but ef you waits till you catches dem birds together, you'll --"

"Oh, give us a rest! You can't get the simplest little thing through your thick skull. Now don't bother me any more."

Jim was satisfied to stop. He was dreadful pleased with himself for catching Tom out. The minute Tom begun to talk about birds I judged he was a goner, because Jim knowed more about birds than both of us put together. You see, he had killed hundreds and hundreds of them, and that's the way to find out about birds. That's the way people does that writes books about birds, and loves them so that they'll go hungry and tired and take any amount of trouble to find a new bird and kill it. Their name is ornithologers, and I could have been an ornithologer myself, because I always loved birds and creatures; and I started out to learn how to be one, and I see a bird setting on a limb of a high tree, singing with its head tilted back and its mouth open, and before I thought I fired, and his song stopped and he fell straight down from the limb, all limp like a rag, and I run and picked him up and he was dead, and his body was warm in my hand, and his head rolled about this way and that, like his neck was broke, and there was a little white skin over his eyes, and one little drop of blood on the side of his head; and, laws! I couldn't see nothing more for the tears; and I hain't never murdered no creature since that warn't doing me no harm, and I ain't going to.

But I was aggravated about that welkin. I wanted to know. I got the subject up again, and then Tom explained, the best he could. He said when a person made a big speech the newspapers said the shouts of the people made the welkin ring. He said they always said that, but none of them ever told what it was, so he allowed it just meant outdoors and up high. Well, that seemed sensible enough, so I was satisfied, and said so. That pleased Tom and put him in a good humor again, and he says:

"Well, it's all right, then; and we'll let bygones be bygones. I don't know for certain what a welkin is, but when we land in London we'll make it ring, anyway, and don't you forget it."

[Tom Sawyer Abroad, by Mark Twain]