Studies for the design of a mechanical perpetual wheel

In the perpetual wheels illustrated on this sheet Leonardo introduces a system of mechanical adjustment of the counterweighted arms, which rotate not only by the effect of gravity but also thanks to the introduction of an actuator rack-and-pinion that opens or closes the arms to create the overbalance in the direction of rotation. Leonardo takes into consideration three distinct cases, with arms of different lengths and mounted on rotors of differing diameters. The principle of operation of this wheel is based on the partial toothing constructed along the circumference of the rotors which, during the rotation of the system, then meshes into two racks placed along the circumference. In this way, two diametrically opposed arms are moved at the same time, one when opening and the other when closing, thus determining a break in the balance in the moments of the system for each pair of arms, which should keep the wheel rotating. These studies date back to a time when Leonardo had already demonstrated the impossibility of perpetual motion; however, below the drawing he added: “this seems a good way and so on,” a comment which suggests that, despite the failures, he still considered the research on perpetual motion a viable path.