The Aristo was made in Germany (date unknown) and resembles a large, blank slide rule. It was used as a training device for prospective cryptanalysts. Characters were written into the blank cells along the edges and the inner slider using a non-permanent marker. By moving the inner slider, the alphabets were shifted relative to one another. After use, the characters could be wiped away and the device re-used. One Aristo is held in the collection of John Alexander and there is another example on display in a German code and cipher museum. Aristo dimensions are: 60 x 6 x 1 centimeters. Storage box dimensions: 63 x 8 x 4 centimeters.

ARISTO is a trademark of the German company Dennert & Pape which  produces drawing equipment and slide rules.

Photo and copy courtesy John Alexander, G7GCK

Contributors and Credits:

1) Gerhard Katz <spital8katz(at)web.d>

Jun 23/13