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 changed accordingly.
Duplicated section headings have been omitted.
Footnotes were moved to the end of chapters and numbered in one continuous sequence.