In 1960 Martin Gardner introduced Scientific American readers to Dr. Matrix, the too-clever-by-half numerologist and con man, with his voluptuous Eurasian daughter-cum-secretary Iva. Gathered here in chronological order are some of the fabulous exploits of the doctor: his political prognostications (the importance of double letters or a terminal ""on"" in your name if you're going to be president), predictions based on the digits in a given year, and the startling numerical coincidences relating the Lincoln and Kennedy assassinations, to name a few. Gardner brings to this kind of number play the right mix of coincidence, curiosity, and spoof to elicit the reader's smile. Meanwhile the ingenuity of the doctor's numerical concoctions serves to introduce challenging problems in number theory. There are also alphabetic codes, hidden acrostics, anagrams, and some geometric and calendar puzzles. Gardner includes the column in which the scoundrelly doctor decides to use ""pyramid power""--the belief that models of Cheops' pyramid (from shelfto live-in size) do all those things snake oil used to be famous for. To his amazement many readers took the column seriously, wrote for information about the pyramid factory, and so on. . . proving once again that there's one born every minute. This is a witty collection for puzzlers and punsters who are good with pencil and paper, but even the lazys will enjoy the gee whiz aspects of number power.