All of his life’s work, including his apprenticeships, schooling, and design, seemed to have prepared him for this monumental assignment. For more than a century, the roof of the dome was open to the elements. The assignment had dismayed many an architect during this period. Several domes had been constructed using cement, but the formula for concrete had been lost during the Dark Ages. The architects were also leery of using the common flying buttresses of the Gothic style; they wanted the design to reflect the clean lines and simple style of their Greek and Roman past. Brunelleschi solved the dome-shaped puzzle with the idea to build two domes - a lighter, outer dome and a heavier, inner dome. The outer dome was constructed using brick and mortar placed in a herringbone pattern to eliminate the need for a central support. The inner dome was made using sandstone beams and marble from local quarries. This choice of materials had a hand in his winning of the commission, as it greatly reduced the cost of labor and…