prime+mover
131Stirling engine — Alpha type Stirling engine. There are two cylinders. The expansion cylinder (red) is maintained at a high temperature while the compression cylinder (blue) is cooled. The passage between the two cylinders contains the regenerator …
132Dynamics of the celestial spheres — Fourteenth century drawing of angels turning the celestial spheres Ancient, medieval and Renaissance astronomers and philosophers developed many different theories about the dynamics of the celestial spheres. They explained the motions of the… …
