Official Business
Penalty for Private Use, $300
Postage and Fees Paid
National Aeronautics and Space Administration
NASA-451
Transcriber’s Notes
- Retained publication information from the printed edition: this eBook is public-domain in the country of publication.
- Silently corrected a few palpable typos.
- Added a Table of Contents.
- In the text versions only, text in italics is delimited by _underscores_.