Punctuation, hyphenation, and spelling were made consistent when a predominant preference was found in this book; otherwise they were not changed.

Simple typographical errors were corrected; occasional unbalanced quotation marks retained.

List of Illustrations: The page number for Illustration 16 was hand-written as “76”, which is the page it faces in the book; and “On the cover” was crossed out. A different edition of this book included neither this illustration nor the cover.