The Fifth Hammer: Pythagoras and the Disharmony of the World by Daniel Heller-Roazen
Publisher: Zone Books; First Edition edition | 2011 | ISBN: 193540816X | 173 pages | PDF (scan) | 17,5 MB
An ancient tradition holds that Pythagoras discovered the secrets of harmony within a forge when he came across five men hammering with five hammers, producing a wondrous sound. Four of the five hammers stood in a marvelous set of proportions, harmonizing; but there was also a fifth hammer.