While in Florence around 1502 or 1503, Leonardo da Vinci pursued a position as a scientist and engineer in the court of Sultan Beyazid II of Istanbul. To showcase his innovative ideas, he sent a “cover letter” to the Sultan proposing four projects: a windmill, a hydraulic pump, a bridge connecting Galata to Istanbul, and a suspension bridge across the Bosporus connecting Turkey and Asia. The bridge connecting Galata to Istanbul across the Golden Horn was da Vinci’s first formal proposal for a self-supporting arched bridge. As proposed, the bridge would be the longest single span bridge at the time and self supporting due to the parabolic shape of the arches underneath it. The sultan rejected this radical proposal and da Vinci’s design remained unused. The connection between this letter and da Vinci's sketches of the arched bridge design was established in 1952, as the letter, stored in the Istanbul National Archives, had been mislabeled and misattributed. The letter is now on display in the Topkapi museum in Istanbul.

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...

Erik Cleves, K. (2014, April 8). [Galata]. Retrieved May 11, 2019, from https://commons.wikimedia.org/wiki/File:Galata_(13971741453).jpg

The image was taken by Erik Cleves Kristensen and is licensed under the Creative Commons Attribution 2.0 Generic license. It is provided through Wikimedia Commons.