In transcribing this item for the next issue of Casefile Clues, I realized that there's a chance it was written by the man who witnessed it--Agusta Newman.
I'm not entirely convinced yet. One difficulty is that the black and white nature of the image hides some clues.
Why do I care?
Agusta Newman is my 4th great-grandfather and having a copy of something written in his hand would be a really neat find.