A 24-foot horse sculpture was commissioned by the Duke of Milan to be built, and Da Vinci did not back out of this challenge. If built it would have been the largest sculpture of a horse in that period. To do so, Da Vinci created a miniature beeswax model to emulate the 24-foot model. He even conquered design challenges like mold making and heating a large amount of bronze for the sculpture through his notes. However, the amount of bronze required was bartered for the prevention of invasion by the French. Thus he did not practice the various design methods he conceptualized. However, the sculpture is now renown to be unlike any other work of his, especially because of the contrast of his earlier works as an apprentice. Moreover, there is an impression of a thumb on the rider’s chest that is said to be Leonardo’s.

Sources:-

“Colossus.” Leonardo da Vinci's Colossus Invention, www.da-vinci-inventions.com/colossus.aspx.

“Horse and Rider (Leonardo da Vinci).” Wikipedia, Wikimedia Foundation, 7 Mar. 2018, en.wikipedia.org/wiki/Horse_and_Rider_(Leonardo_da_Vinci).

Image Courtesy:- Wikimedia Commons , public domain

https://commons.wikimedia.org/wiki/File:Leonardo_Da_Vinci_Horse_and_Ride...