Minor typographical errors have been corrected without note.
Punctuation and spelling were made consistent when a predominant
form was found in this book; otherwise they were not changed.
Ambiguous hyphens at the ends of lines were retained.
Mid-paragraph illustrations have been moved between paragraphs
and some illustrations have been moved closer to the text that
references them. The List of Illustrations paginations were not
corrected.
Footnotes were moved to the ends of the text and numbered in one
continuous sequence.