In paragraph LXX of Pneumatics, Heron presents a particular device that reproduces a sacrificial altar. Covered by a glass lid, a hollow tube rests on a pin in the centre of the circular base. At the lower extremity of the tube, and connected to it, two small pipes are bent at right angles. Figurines simulating a dance are placed on the revolving base. When the sacrificial fire is lit on top, the heated air starts circulating inside the container where, contained by the lid, it is transformed into energy that generates the motion of the figurines situated on the apparatus base. The device, in substance, demonstrates how the energy produced by storing heat can be exploited to produce forms of motion.