Codes and Ciphers // _29-90-00-00

The history of war teems with occasions where the interception of dispatches and orders written in plain language has resulted in defeat and disaster for the force whose intentions thus became known at once to the enemy. For this reason, prudent generals have used cipher and code messages from time immemorial. The necessity for exact expression of ideas practically excludes the use of codes for military work although it is possible that a special tactical code might be useful for preparation of tactical orders. _39-94-01-01 >>

Codes in Use // _29-90-00-00

The codes of the Western Union and Postal Telegraph companies are examples of well-known codes suited to general commercial use. Besides these, many special codes have been formulated, so as to embody technical expressions especially adapted to use in particular lines of industry. The War Department Code is a military code adapted to the special needs of the military establishment in peace and war. _39-94-01-01 >>

Code Employment // _29-90-00-00

Codes are primarily intended for economy, but they may also be readily employed to secure secrecy. When used solely for economy, the coded message is said to be plain code; that is, the word or phrases of the message are coded by direct reference to their respective code equivalents. Thus plain code is readily translatable to anyone in possession of a code book. When secrecy is desired, some method of enciphering or key is employed in such a way that only persons in possession of it can in conjunction with the code book decipher it. In such case the message is said to be in cipher code. _39-94-01-01 >>


...I suspect it requires a special gift of grace to enable one to hear the bird-songs; some new power must be added to the ear, or some obstruction removed.  There are not only scales upon our eyes so that we do not see, there are scales upon our ears so that we do not hear. A city woman who had spent much of her time in the country once asked a well-known ornithologist to take her where she could hear the bluebird. "What, never heard the bluebird!" said he. "I have not," said the woman. "Then you will never hear it," said the bird-lover. Bird-songs are not music, properly speaking, but only suggestions of music.  A great many people whose attention would be quickly arrested by the same volume of sound made by a musical instrument or by artificial means never hear them at all... _29-90-00-00 >>