Christies is auctioning the first-ever telephone book: The Telephone Directory, Vol. 1, No. 1, for New Haven, Connecticut, November 1878.

The instructions provided in the Directory for correct use of the telephone, the first such directions ever published, include much sound advice: "Never take the Telephone off the hook unless you wish to use it....Should you wish to speak to another subscriber... you should...commence the conversation by saying 'Hulloa!' When you are done talking, say 'That is all!', and the person spoken to should say 'O.K.' ... While talking, always speak slow and distinct, and let the telephone rest lightly against your upper lip, leaving the lower lip and the jaw free..." The push button phone bore slightly different requirements: "After speaking, transfer the telephone from the mount to the ear very promptly ... When replying to a communication from another, do not speak too promptly ... Much trouble ensues from both parties speaking at the same time.... No subscriber will be allowed to use the wire for more than three minutes at a time, or more than twice in an hour, without first obtaining permission from the main office... Any person using profane or otherwise improper langauge, should be reported at this office immediately." (pp. 4-5).

[via Gizmodo]