On August 19, 1418, a competition concerning Florence's magnificent new cathedral, Santa Maria del Fiore was announced: "Whoever desires to make any model or design for the vaulting of the main Dome . . . shall do so before the end of the month of September." The proposed dome was regarded far and wide as all but impossible to build. The dome would literally need to be erected over thin air. Of the many plans submitted, one stood out. It was offered not by a master mason or carpenter, but by a goldsmith and clockmaker named Filippo Brunelleschi, who would dedicate the next twenty-eight years to solving the puzzles of the dome's construction. In the process, he did nothing less than reinvent the field of architecture. Brunelleschi's Dome is the story of how a Renaissance genius bent men, materials, and the very forces of nature to build an architectural wonder we continue to marvel at today. Denounced at first as a madman, Brunelleschi was celebrated at the end as a genius. He engineered the perfect placement of brick and stone, built ingenious hoists and cranes to carry an estimated 70 million pounds hundreds of feet into the air, and designed the workers' platforms and routines so carefully that only one man died during the decades of construction.