Secret Correspondence By Music
Form a circle like Fig. 2, divided into twenty-six parts, with a
letter of the alphabet written in each. The interior of the circle is
moveable, like that in Fig. 1, and the circumference is to be ruled
like music-paper. Place in each division a note different in figure or
position.
Within the musical lines place the three keys, and on the outer circle
the figures to denote time. Then get a ruled paper, and place one of
the keys (suppose ge-re-sol) against the time 2-4ths, at the
beginning of the paper, which will inform your correspondent how to
place his circle. You then copy the notes that answer to the letters
of the words you intend to write, in the manner expressed above.