A H I P Q X D E L M T U X Q P I H A U T M L E D B G J O R W C F K N S V W R O J G B V S N K F C C F K N S V B G J O R W V S N K F C W R O J G B D E L M T U A H I P Q X U T M L E D X Q P I H A (e) Simple Diagonal: A B D G K O G K O S V X O K G D B A X V S O K G C E H L P S D H L P T W S P L H E C W T P L H D F I M Q T V B E I M Q U V T Q M I F U Q M I E B J N R U W X A C F J N R X W U R N J R N J F C A A C F J N R J N R U W X R N J F C A X W U R N J B E I M Q U F I M Q T V U Q M I E B V T Q M I F D H L P T W C E H L P S W T P L H D S P L H E C G K O S V X A B D G K O X V S O K G O K G D B A (f) Alternate Diagonal: A B F G N O G N O U V X O N G F B A X V U O N G C E H M P U F H M P T W U P M H E C W T P M H F D I L Q T V B E I L Q S V T Q L I D S Q L I E B J K R S W X A C D J K R X W S R K J R K J D C A A C D J K R J K R S W X R K J D C A X W S R K J B E I L Q S D I L Q T V S Q L I E B V T Q L I D F H M P T W C E H M P U W T P M H F U P M H E C G N O U V X A B F G N O X V U O N G O N G F B A (g) Spiral, clockwise: A B C D E F L M N O P A I J K L M N D E F G H I P Q R S T G K V W X Q B H U V W X O C R S T U J O X W V U H J U T S R C G T S R Q P B Q X W V K N M L K J I I H G F E D F E D C B A A P O N M L (h) Spiral, counter clockwise: A P O N M L N M L K J I I H G F E D F E D C B A B Q X W V K O X W V U H J U T S R C G T S R Q P C R S T U J P Q R S T G K V W X Q B H U V W X O D E F G H I A B C D E F L M N O P A I J K L M N It is simply a matter of inspection to read a message in a cipher of this type, once the dimensions of the rectangles have been determined. We place the whole or a portion of the message in such rectangles and read horizontally, vertically and diagonally forward and backward. Parts of words will at once be apparent and the whole message is soon deciphered. Two examples will show the process. Message ILVGIOIAEITSRNMANHMNG This message contains eight vowels or 38% out of twenty-one letters, and the letters LNRST occur 7 times or 33%, the letters XQJKZ not appearing. It is therefore a transposition cipher. Twenty-one letters immediately suggest seven columns of three letters each or three columns of seven letters each. Trying the former we have: I L V G I O I A E I T S R N M A N H M N G and reading down each column in succession (Case 1-b) reveals the message to be "I am leaving this morning." Message