A. The 18th-century English hornbook shown in our May 2008 History Matters column (here’s the hornbook—it’s from the Library of Congress Rare Book and Special Collections division) features a character called the long s.
The long s, which looks like a lower-case f, was common in 18th-century England and Colonial New England. It was often used as an s at the beginning or in the middle of a word (as in fentiment), or as one or both letters of a double s (congrefs).
The long s was not generally used as the final letter of a word—for that, people used the familiar short, or terminal, s.
The long s fell out of use around 1800 in England and 1820 in the United States.
For more on the long s, see Wikipedia’s well-illustrated article and the book Researching Your Colonial New England Ancestors By Patricia Law Hatcher (Ancestry, $16.95).
The book is available for a limited preview in Google; I’ve added it to Family Tree Magazine’s Google Library for your linking convenience.