George Smith 
Highways in Hiding 

In the founding days of Rhine Institute the need arose for a new punctuation mark which would indicate on the printed page that the passage was of mental origin, just as the familiar quotation marks indicate that the words between them were of verbal origin. Accordingly, the symbol # was chosen, primarily because it appears on every typewriter. Up to the present time, the use of the symbol # to indicate directed mental communication has been restricted to technical papers, term theses, and scholarly treatises by professors, scholars, and students of telepathy. Here, for the first time in any popular work, the symbol # is used to signify that the passage between the marks was mental communication.