EditorialThe Limits to Growth (LTG) is a 1972 report on the exponential economic and population growth with a finite supply of resources, studied by computer simulation. The study used the World3 computer model to simulate the consequence of interactions betwe...
EditorialModel of a Double Pair or Hydraulic Forge Bellows, Model of a double hydraulic bellows on a floorboard. It consists of two vessels and a drive mechanism that is incomplete. Each vessel has a cylinder inside that connects top and bottom, the space insid...
EditorialModel of a Pair of Hydraulic Forge Bellows, Model of a hydraulic bellows on a floorboard. It consists of a barrel that is hung horizontally in two forks and can be turned a quarter circle around its axis by means of a lever. The space inside is transfo...