A good example matrix, usedthroughout this book, appearsin the Renaissance engravingMelancholia I by the Germanartist and amateurmathematician Albrecht D?This image is filled withmathematical symbolism, and ifyou look carefully, you will see amatrix in the upper rightcorner. This matrix is known asa magic square and wasbelieved by many in D?time to have genuinely magicalproperties. It does turn out tohave some fascinatingcharacteristics worth exploring. ! _8 ]1 P- t# {- z) u$ q1 ` ) B( U( H, t7 m9 ]0 U+ b7 q' N& f7 I, O, ]7 G! a! w