The 1878 telephone directory for New Haven, Connecticut, is expected to fetch bids of more than $30,000. The first commercial telephone service began in New Haven in January 1878, and the telephone directory was printed the following November. It lists about 400 telephone users.
The early phone book includes directions for proper use of the phone, such as, "Commence the conversation by saying, 'Hulloa!' When you are done talking, say "That is all!" and the person spoken to should say, "O.K." The book also warns, "Much trouble ensues from both parties speaking at the same time."
The copy of the telephone book at Christie's is believed to be the only surviving copy. Just as now, people disposed of the old phone books when new ones were issued.