Cannon foundry
by LEONARDO da Vinci, Pen and ink on paper
The project for casting a gigantic cannon leads us to assume that Leonardo was familiar with the customary process for casting cannon. The heavy cannon was to be moved by means of levers and block and tackle, then to be mounted on a moving undercarriage. Even though this is merely a drawing on a technical subject, one can clearly see what an enormous effort the figures are having to make to shift the weight.