Heron’s automated temple gates

Study: D. Kalligeropoulos
Construction: D. Kalligeropoulos, B. Nikolis, P. Vasileiadis
 
 
"A temple is constructed such that as soon as a fire is lit on the altar before it, and the sacrifice is made, the doors of the temple open automatically; and as soon as the fire is quenched, they close again" (Heron, Theorem 38, “Pneumatika”). In this mechanism, Heron exploited the expansion of air heated beneath the altar. The pressure of the air forces a liquid to move from a fixed vessel into a movable one, after which a system of pulleys and counterweights is activated to pivot the doors of the temple.