Studies for the design of a mechanical perpetual wheel

The main theme of this clipboard, as shown by the drawings of check valves and water wheels, is the lifting of water. The longest note describes the opening system of a valve operated by a float (a pumpkin) applied in a curious and not very clear rotary bellows compartment. The system of filling and emptying the compartments which the air jet produces brings to mind a perpetual wheel and, in fact, together with the section drawings of this bellows, Leonardo copies across the sketch of the traditional semi-circular wheel of Indian origin and the perpetual wheel with door illustrated on folio 50r of Manuscript E. According to Marinoni, this rotary bellows is connected to a similar bellows drawn in Manuscript B (ff. 81r and 82r). The proposed date for this sheet is 1515: it is worth noting that, once again, when studying rotary systems with a break in the equilibrium (here induced by the liquid), Leonardo returns to past research on perpetual wheels. This shows that this topic of research, despite repeated failures, still aroused his interest.