If you begin at the first page and count the first ten letters after every
widely spaced apostrophe, and then read them backwards, you will discover
that among those ten letters a word is spelled (the words may be less than
ten letters long). By the end of the book you will have discovered Twain's
secret message to the world (do not assume it will be in English).

OK, now that we've distracted the nitwits and Shakespearean scholars on this
list, I can tell you what is really going on.  At a first glance at the
first page of the text to chapter 9, it would seem that contractions were
spaced widely before the apostrophe and that possessives are spaced
normally. But if you look at other pages, this pattern clearly does not
hold. But if you look at enough other examples you will begin to notice that
the lines of type containing a widely spaced apostrophe also have widely
spaced words in the entire line, and that lines containing normally spaced
apostrophes have normally spaced words. As one experienced in setting type
by hand, I can tell you that when setting type, not every line spaces out
perfectly, and in order to justify a line of type (to make it more
attractive, more readable, and so it won't work loose during printing or
plate-making) the type-setter must go back through every line and either
"tighten" the spacing by substituting narrower spaces between words, or
space out the words using em or en quads (the spacers normally used between
words) or "brasses" or "coppers" (the much thinner spacers used for
fine-tuning between words and even letters). This is usually done as you set
each line, but when an entire page is finished, there are usually a line or
two that need a little attention. A line set too tightly tends to bow up
toward the middle and this can create problems like excessive type wear, bad
inking, uneven make-ready, etc. A line set too loose can cause the same
problems, and most often results in individual letters working up and
getting damaged, or working up and being pulled out during plate-making (the
folio at page 155 of HF is a good example of a numeral that worked up, was
damaged, then lost, and then replaced).

What happened in LonM seems clear enough: Whoever set type mistakenly
inserted space before the apostrophes in lines that needed spacing out. I
casually checked some pages in Twain's APC and other Osgood books of that
period, and did not find other examples. If you closely studied the pattern
of such type-setting in LonM you might find that it only occurs in certain
gatherings (the separately type-set and printed sequences of pages, that,
when sewn together, comprise the book). You could then write a lengthly
article about "compositor a and the spacing of apostrophes in the first
octavo edition of Samuel L. Clemens' LIFE ON THE MISSISSIPPI" and get it
published in PBSA alongside those long boring articles on the compositors of
Shakespeare's quarto and folio editions. I've certainly given you a big
headstart and plenty of time, since most the folks who write those articles
are busy right now counting letters backwards and trying to make them into
words.

Kevin Mac Donnell
Austin TX