Perpetual overbalanced wheel
Generating and maintaining motion both as an end in itself (a moving machine) and as a means (a machine that does a job) were the main purposes of mechanical engineering. The invention of a perpetual motion machine to be used eventually also as an engine, would have achieved both these results.
The early folio 1117rb of the Codex Atlanticus, which reproduces the sketch of an overbalanced wheel similar to that drawn by Honnecourt and Taccola, is proof of Leonardo’s early interest in the subject. It can also be linked to a series of sheets of the same codex dating to around the same period, which contain other perpetual motion machines. These studies were essentially developed on a graphic level, from which the effort to find solutions based on the combination of mechanical elements emerges, but without an analysis of the possibility of their functioning.