Every medieval civilization built upward, but each tower answered a different question. In Gothic Europe, height was a prayer and a point of civic pride: flying buttresses, first used on great churches around Paris in the late twelfth century, carried the sideways thrust of stone vaults outward so walls could become thin screens of glass. The spire of Lincoln Cathedral, completed around 1311, reputedly reached about 160 metres and was counted the tallest structure in the world until a storm brought it down in 1548. Beauvais pushed hardest of all — part of its record-high choir vault collapsed in 1284, and its 153-metre tower, briefly the tallest human construction on earth after 1569, fell in 1573. In the Islamic world, the minaret was a tower for the voice: a vantage point from which the muezzin could call the faithful to prayer five times a day, and at the same time a landmark and a statement of the ruler's authority, from the spiral minaret of Samarra (848–852) to Seville's Giralda (completed 1198) and Delhi's 72.5-metre Qutb Minar, begun in 1199 as both minaret and victory tower. In China, builders trusted wood. The pagoda of Fogong Temple at Yingxian, raised in 1056 to a height of 67.31 metres without a single nail, rests on fifty-four kinds of interlocking dougong brackets that absorb shocks through friction and rotation; local records note seven earthquakes in its first half-century, and it still stands. Stone that resists, a voice that reaches, and wood that bends: three different answers to how high, and why.