The chains of Codex Atlanticus and Madrid I in context.
Left a heavy chain with rounded elements to fit around a toothed wheel. The wheel would have less tooths than usual today. Below (Folio 56v-b) a chain type Marioni found close to modern ones. Center the 5th folio of Codex Madrid I were Leonardo suggested toothed wheels with round heads. But later
on folio10v he draw cubic heads that would not work.
/ レオナルド・ダ・ヴィンチ