Hermetic Library Fellow T Polyphilus reviews *Mathematical Magic* by William Simon.

*Mathematical Magic* is an instructional book directed at performing magicians, although occultists and ceremonial magicians may certainly cock an eye at the cover of the Dover edition, which shows the magical square proper to Mercury, in suitable colors even. That’s only appropriate for a book on legerdemain, I suppose!

A full chapter on magic squares makes up the fifth of seven classes of tricks described by Simon, with a variety of rules for constructing both standard squares of the sort used in traditional talismans, and more exotic squares as well–not to mention applications of these figures intended to amaze observers. The first chapter consists of the sort of calculation-based tricks that the title may suggest to readers. In the second chapter, the “mathematics” involved is *topology*, so Simon provides notes on Moebius strips and tricks involving ropes, ties and surfaces. The “calendar magic” of the third chapter does have a mathematical basis, but didn’t strike me as very impressive. Chapter four, on “Mental Magic,” provides some of the most efficient and effective devices for performance. A chapter on magic with common small objects includes one trick that either doesn’t work or isn’t explained sufficiently–I only succeeded with it once out of three tries. The book finishes with an inventory of card tricks that use mathematical principles, but don’t entirely rely on them.

Except for some card moves in the last chapter, the tricks described make no demands on the magician for palming or other special dexterity. Nor is the math especially demanding. As a general rule, Simon begins by describing how the trick will look to observers, continues by detailing the procedure of the magician, and concludes by explaining the math that provides for the trick’s success. All of the tricks are more suited to close-up and casual magic than to formal stage work, although many of them could be quite effective in a parlor-scale act.

One especially valuable feature of this study for me was that it may finally have given me the key to Giacomo Casanova’s “cabala,” that he used in order to impress his acquaintances and intimates with divinatory feats, and to influence their decisions. I now suspect that Casanova used the principle of “casting out the nines” (see Simon’s explanation, 28-29) in order to create large numerical values from which others could “construct the pyramids” that would force the answers he wanted to produce.

Simon, whom his friend and preface-writer Martin Gardner describes as “one of the nation’s most skillful and creative card magicians,” shows not a trace of boasting or egotism in this book, and he is eager to credit his predecessors where he can. With the sole above-noted exception, all of the tricks in this book are lucidly exposed, and likely to be effective for anyone who approaches them with even modest discipline.