Book test
[1][N 1] The modern concept of the book test involves the magician revealing a word, phrase, or image that the spectator has selected at random.
The earliest known example is a variation on the modern Twenty One Card Trick, in which a series of operations reveals the chosen item through basic mathematics.
[1] It is known that a version of this sort of book test was created by well-known publisher Girolamo Scotto and demonstrated for the Emperor of Austria in 1572.
The earliest surviving example was found by Italian magician Vanni Bossi in the book Il Laberinto, originally published in 1607 by Andrea Ghisi.
[3] It is believed Wits laberynth was the inspiration for the same trick in Nicholas Hunt's Newe Recreations, published in London in 1631.
[4][5] Modern variations of the original "labyrinth" concept using gimmicked books are widespread, although they vary greatly in nature.
The first modern example is widely suggested to have been introduced by Johann Nepomuk Hofzinser sometime between 1865 and 1875, generally known simply as "The Word".
[7] James Randi uses the trick as a staple of his impromptu shows, selecting among a wide variety of methods at whim.
These can be distinguished because the mentalist hands the books to the spectator to choose among, and has some sort of riffle or fast flipping of the pages later in the trick.
In cases using the dictionary test principle, the magician holds the book in front of them, facing out.
The most common has the mentalist leaf through the non-force book at high speed and asks the spectator to call "stop" at any point.
There are dozens of variations; Theodore Annemann's Practical Mental Magic describes fourteen in a single chapter and refers to more within the text.
[12] Another major class of book tests involves a mnemonic device to distribute "money words" across a page.
[15] A commercial variation of the dictionary test is known as "Flashback," and comes in the form of a complete gimmicked book.
The "Page, Line and Word" trick uses two or three spectators, handing one a book (the "reader"), another an envelope, and the third pencil and paper (the "writer").
Mathematical forces of this sort, similar to the original "labyrinth" type tests, are no longer common as these are widely known to the audience.
A word or statement from a natural is selected, and then some sort of marker, normally a quarter, is inserted in that page near the spine.
This relies on nothing other than the magician holding the book firmly by the spine while it is riffled, both to obscure the coin as well as to keep it from falling out.
