Study of a perpetual wheel with a variable set up

In folio 557r-v of the Codex Atlanticus, although no explicit reference is made to perpetual motion, we find the study for an articulated wheel with a series of rotating boxes arranged along the circumference, which should be able to push each other. In describing the device, Leonardo refers twice to the “aumento” (increase) given to the wheel by this kinematics. It was thought that this unspecified physical quantity, with which Leonardo referred to the impetus of the flywheels (which he called the “ruota dell’aumento” (augmentative wheel) precisely because of their ability to maintain the rotation9), could be controlled and amplified by adding the forces generated by the movement of the peripheral boxes mounted on this wheel. The use of the term “polificata” (distributed on a series of shafts), a hapax in all of Leonardo’s handwritten production, is very significant in this context. It gives a good account of the pioneering nature of his studies, which sometimes did not find alternative terms in the technical- scientific lexicon of the day to express the concepts developed. Leonardo uses this term while trying to identify the main obstacle to impetus in the rotary systems, namely the friction acting on the pole (centre) of rotation. By “polificare l’asse” Leonardo intends to break up the force acting on the pole that makes it brake and consumes it, in order to distribute it over many poles. The process, clearly comparable to that of bearings, recalls the anti-friction systems with semicircular sectors he studied at the beginning of the 1490s and applied to the bells’ bearing.