How to Write Codes and Send Secret Messages
Explains how to write and decipher space codes, hidden word codes, and alphabet codes and gives formulas for invisible ink. Includes suggestions for delivering coded messages.
$3.25
Original: $10.85
-70%How to Write Codes and Send Secret Messages—
$10.85
$3.25
Description
Explains how to write and decipher space codes, hidden word codes, and alphabet codes and gives formulas for invisible ink. Includes suggestions for delivering coded messages.
