I was reading up on primers and found this in your faq:

"For using the book as a text for children, it would be the printing and spelling that is used in it. For example the letter "f" was frequently substituted for "s". (I don' know why.) "

The letter that is substituted is actually the long-s. If you look carefully you will find that the horizontal bar only appears on the left and not the right of the character (unlike the f). You will find some more information here:

from http://nwalsh.com/comp.fonts/FAQ/cf_6.htm#SEC11

What is the ``f'' shaped ``s'' called? Both the ``f'' with half a crosbar (roman) and the integral sign (italic) are called long-S.

from http://nwalsh.com/comp.fonts/FAQ/cf_16.htm#SEC51
...
Ligatures were originally used by medieval scribes to conserve space and increase writing speed.  A 14th century manuscript, for example, will include hundreds of ligatures (this is also where ``accents'' came from).  Early typefaces used ligatures in order to emulate the appearance of hand-lettered manuscripts.  As typesetting became more automated, most of these ligatures fell out of common use.  It is only recently that computer based typesetting has encouraged people to start using them again (although 'fine art' printers have used them all along).  Generally, ligatures work best in typefaces which are derived from calligraphic letterforms.  Also useful are contextual forms, such as swash capitals, terminal characters, and so on.

A good example of a computer typeface with a rich set of ligatures is Adobe Caslon (including Adobe Caslon Expert). It includes:
Upper case, lower case, small caps, lining numerals, oldstyle numerals, vulgar fractions, superior and inferior numerals, swash italic caps, ornaments, long s, and the following ligatures: ff fi fl ffi ffl Rp ct st Sh Si Sl SS St (where S=long s) ...

While I appreciate your work in updating the primer, I think it is important to realize the history and art that was behind the original. Thanks.
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