The invisible enemy, by Jerry Sohl                                        79645

  [Author: Jerry Sohl]

  [Illustrator: Harold W.  McCauley]

  [Illustrator: Lloyd  Rognan]

  [Link: https://www.gutenberg.org/ebooks/79645]

  note: link will be active within two hours of posting.

Thanks to Tom Trussel - Stories of Futures Past (This file was produced

from images generously made available by The Internet Archive).

Regards,

Robert