Old-time Telephones
Very informative book: for the collector, restorer and even the technician. Probably the best technical information widely available on the development of the US Public Telephone system subscriber instruments from turn-of-the-century local battery-magneto to the Princess and Trimlines. Covers development, design and even touches on the corporate thinking which influenced this. Keeps the interest of the engineer but not so technical that the amateur shouldn't be able to follow it too. While the emphasis is on Bell phones, the other major competitor's equivalents are covered as well.