Leonardo da Vinci was a proficient engineer as well as artist, and among his designs was a bridge entirely supported by the parabolic arch underneath it. His notebook includes two illustrations of this arched bridge. He specified that the bridge, which would span the Golden Horn connecting Galata to Istanbul, would be 600 braccia long, which is equivalent to 366 m or 1200 ft; 400 braccia spanned the inlet itself, with 100 braccia over the land on either side. At its highest point, the arch would rise 70 braccia, or 43 m, above the water. While da Vinci was correct in asserting that a parabolic shape would offer extraordinarily strong support, the exact mathematical techniques required to build a bridge of this design were not developed until centuries later. These sketches, found in Manuscript L, are currently located at the Institut de France in Paris.

Sources:

Atalay, B. (2013, January 22). LEONARDO’S BRIDGE: Part 2. “A Bridge for the Sultan”. Retrieved May 11, 2019, from https://blog.nationalgeographic.org/2013/01/22/leonardos-bridge-part-2-a...

Books, Maps and Calligraphic documents in the Topkapi Museum. (n.d.). Retrieved May 12, 2019, from http://kilyos.ee.bilkent.edu.tr/~history/booknmaps.html

C. (2011, April 10). Bridge built using Leonardo da Vinci's design for a self supporting bridge.Retrieved May 12, 2019, from https://commons.wikimedia.org/wiki/File:Leonardo_da_Vinci_bridge_Karby.jpg (Originally photographed 2011, April 10)

The image is from Wikimedia Commons and taken by user Cntrading. It is used with the Free Art License.