And it takes them weeks and weeks and weeks, and for ever and ever.  Why, look at one of them prisoners in the bottom dungeon of the Castle Deef, in the harbor of Marseilles, that dug himself out that way; how long was _he_ at it, you reckon?” “I don't know.” “Well, guess.” “I don't know.  A month and a half.” “_Thirty-seven year_--and he come out in China.  _That's_ the kind.  I wish the bottom of _this_ fortress was solid rock.” “_Jim_ don't know nobody in China.” “What's _that_ got to do with it?  Neither did that other fellow.  But you're always a-wandering off on a side issue.  Why can't you stick to the main point?” “All right--I don't care where he comes out, so he _comes_ out; and Jim don't, either, I reckon.  But there's one thing, anyway--Jim's too old to be dug out with a case-knife.  He won't last.” “Yes he will _last_, too.  You don't reckon it's going to take thirty-seven years to dig out through a _dirt_ foundation, do you?” “How long will it take, Tom?” “Well, we can't resk being as long as we ought to, because it mayn't take very long for Uncle Silas to hear from down there by New Orleans.  He'll hear Jim ain't from there.  Then his next move will be to advertise Jim, or something like that.  So we can't resk being as long digging him out as we ought to.  By rights I reckon we ought to be a couple of years; but we can't.  Things being so uncertain, what I recommend is this:  that we really dig right in, as quick as we can; and after that, we can _let on_, to ourselves, that we was at it thirty-seven years.  Then we can snatch him out and rush him away the first time there's an alarm.  Yes, I reckon that 'll be the best way.” “Now, there's _sense_ in that,” I says. “Letting on don't cost nothing; letting on ain't no trouble; and if it's any object, I don't mind letting on we was at it a hundred and fifty year.  It wouldn't strain me none, after I got my hand in.  So I'll mosey along now, and smouch a couple of case-knives.” “Smouch thr