The original system used numbered, wooden wheels and a spindle with two end caps. Each wheel had all 26 letters around the edge in random order. The Sender noted the order in which wheels were placed on the spindle. Then, each wheel was rotated as necessary to spell out the message. Finally, the caps were pressed tight so that all wheels rotated together and the spindle was rotated to any other row which became the encyphered message. The wheel order and the encyphered message were went to the Receiver (separate messages) who reversed the steps to recover the plain text message.
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