★ U. S. GOVERNMENT PRINTING OFFICE: 1972 O-456-399
Transcriber’s Notes
- Retained publication information from the printed edition: this eBook is public-domain in the country of publication.
- Relocated all image captions to be immediately under the corresponding images, removing redundant references like ”preceding page”.
- Silently corrected a few palpable typos.
- In the text versions only, text in italics is delimited by _underscores_.