Chess-like Game of Strategy.- Boissiere (Claude de) Le Tres Excellent et Ancien Jeu Pythagorique, dict Rhythmomachie..., first edition, collation: A-I⁴, woodcut device on title and armorial illustration on verso, woodcut illustrations in text, a few leaves with repairs to corners or margins, occasional soiling, modern calf, gilt, by Courtland Benson, 8vo (159 x 100mm.), Paris, Annet Briere, 1554.

⁂ Extremely rare first edition. Not in Smith Rara Arithmetica, which mentions only the second edition of 1556. "Claudius Buxerius (Claude de Boissière) was born in the diocese of Grenoble, probably c. 1500, He also wrote on poetry, music and astronomy...Of the three standard treatises on the ancient number game of Rythmomachia mentioned in this list, the others being one of 1496 of uncertain authorship and Barozzi's work of 1572, this is the clearest. It describes very carefully the checkerboard on which the game is played, the nature of the calculi used, and the general mode of procedure. Moreover, it is profusely illustrated, which adds much to the value of the book. The game was connected with the mediaeval number classifications and ratios, and could never have been understood by any save those who were well educated in ancient theoretical arithmetic." (Smith, Rara Arithmetica).

Rithmomachia was a strategy game for two players. A black and a white party of numbers face each other, similar to chess. There was a time when Rithmomachia was in competition with chess and was even more respected than chess, for example in some mediaeval treatises Rithmomachia was favoured. (Folkerts 1989) The reason was, that Rithmomachia was the only game in the curriculum of mediaeval schools and universities - an honour which chess had never received, because it was played as a tactical war game in the nobility for pure entertainment, but it did not suit the canon of the seven liberal arts. In Rithmomachia the aim is not to fight against each other with armies of numbers, rather to take part in a contest, where the players must bring some of their pieces into a harmonious order.

Literature: Boissiere's Pythagorean Game by John F. C. Richards, Scripta Mathematica 12: 177-217, 1946; See also: "Illmer, Detlef & Gädeke, Nora, & Henge, Elisabeth & Pfeiffer, Helene & Spickler-Beck, Monika. Rhythmomachia. Hugendubel Verlag (1987)"; On Rythmomachia see also Spielerische Seiten. Herzog August bibl. p. 21 ef; Brunet I 1072. (Livre rare), non reseigné par Caillet; Not in K.V.K. (only 1556 edition); Not in Biblothèque Nationale de Paris.