The Cipher Wheel

To work the Cipher Wheel, set the A on the outer ring to the letter of the keyword being used, then the outer letters represent the ciphertext, and the inner letters represent the plaintext.

Emily Lapisardi, as Rose, displays a wooden cipher wheel, the type used in Civil War times. Photo from Ann Blackman and Emily's presentation at the Spy Museum in Washinton, DC in June, 2005.