What you need
The printed template
Card
Scissors
Sticky tape
A pencil to thread them on
How to build it
Cut out the six stripsEach strip is one ring, and each has a different scrambled alphabet on it.
Roll each strip into a ringTape the ends so the letters run all the way round with no gap.
Thread them onto the pencilIn any order you like. That order is your key, and it must be written down.
Spell your message along the ringsTurn each ring until your letters line up in one straight row across all six.
Now copy a different rowAny other row. That row of six letters is your cipher text.
Send the row and nothing elseYour friend threads their rings in the same order, spells out your row, and looks round the wheel for the line that makes sense.
Number the rings on the inside before you thread them. Once they are on the pencil they all look the same, and the order is the key.
The template
Print this at 100 per cent, not fit to page, or the sizes will be wrong. The ruler line below tells you whether it printed correctly.
The bar above should measure exactly 10 centimetres. If it does not, your printer has shrunk the page.
Now send something
Six letters at a time is the whole message length, so start with SIXTHS or PENCIL and work up.
Lewis Carroll’s tableBack to Make