Cryptanalysis of the Enigma Bletchley Park to describe the network that used the same Enigma setting sheets. Initially these were recorded using coloured pencils and were given the names "red", "light blue" etc., and later the names of birds such as "kestrel". During World War II the settings for most networks lasted for 24 hours, although towards the end of the war, some were changed more frequently. The sheets had columns specifying, for each day of the month, the rotors to be used and their positions, the ring positions and the plugboard connections. For security, the dates were in reverse chronological order down the
The Man That Was Used Up story seems to suggest that the war hero has nothing left but the injuries he has received in battle to make up his identity. According to Shawn James Rosenheim, Poe also is questioning technology, suggesting that it will soon be difficult to distinguish man from machine. The story also has minor critiques of racism; the war hero was taken apart by Indians but is put together by his "old negro valet" named Pompey (a name Poe also uses in "A Predicament"), arguably undermining the power of white male dominance. Poe may also have been reacting to the popular "subversive" humor