Gunshots, wind, melodies, water jets and bubbling: hydraulic valves for the Teatro delle Acque of Villa Aldobrandini in Frascati

Despite the size of the bibliography on the iconology of nymphaea and water theatres in the Italian villas built between the sixteenth and the seventeenth centuries, studies on the hydraulic systems of giochi di acqua (the hydraulic systems used to make water games and jokes) are still scarce. The complexity in the design of giochi di acqua is suggested by the increases in technical treatises on the subject in the period, such as those of Giovan Battista Aleotti (1605-19, also translator of Gli Artificiosi e curiosi moti spiritali d’Herrone Alessandrino) and Francesco Fontana (1696) [1]. Architectural and hydraulic projects were indeed inextricably connected, not only technically, as we would expect, but also compositionally, since water, in all its several shapes (tubes, nozzles, blades, weir terminals, etc.), changed the optical, auditory and even olfactory perception of the sites. While it normally consisted of sculptures, vegetation and fountains, accompanied by an incessant dripping, on great occasions water theatres sprang to life to amaze, terrify, amuse the guests. They became the scenography of spirited plays combining mythological tales, melodies, mechanical chirping birds, substances dissolved in the water, jets, bubbles and pinwheels (girandole) of water, sudden frightening noises, fire and smoke, wind and impertinent jokes of water, according to a fixed repertoire that was recurrent in the villas built in that period [2]. Nowadays such fountains, often deprived of water (which, although vital, is also a cause of degradation), are a pale image of their original magnificence. The exuberant effects animating the fountains, and the few iconographical sources, were recorded in detail in the descriptions made by travellers between the eighteenth and the twentieth centuries (such as that of Lawson, dating to 1915-20) and in precious archival document