Da Vinci wasn’t only thinking about human flight and warfare. He also predicted a number of practical appliance ideas, like an early prototype for a “cooling machine” – also known as a refrigerator.
Scholar Alessandro Vezzosi believes that da Vinci conceptualized the cooling machine while still under the patronage of the Sforzas in Milan circa 1492.
Da Vinci’s sketch shows an intricate system of bellows, leather chambers, and spouts that seem pretty bulky for something that doesn’t actually keep all that much cooler.
It’s unknown whether da Vinci ever actually attempted to build this “cooling machine,” but it’s thought to be the earliest known attempt at refrigeration – and he predicted this now-ubiquitous technology long before anyone even began considering the need for it.