- Retained publication information from the printed edition: this eBook is public-domain in the country of publication.
- Silently corrected a few palpable typos.
- Moved illustrations to the nearest paragraph break.
- In the text versions only, text in italics is delimited by _underscores_.
- In the text versions only, superscript text is preceded by caret.
- In the ASCII version only, subscripted numbers are preceded by underscore and delimited by brackets.