Coffee maker

This coffee maker works based on a vacuum principle that was conceived in Germany in 1827. The two heat-resistant tanks are connected together. The glass tank contains water that is heated electrically. The produced vapour condenses in the second tank, which contains the loose filter coffee. When the heating is stopped, the air contracts and draws a vacuum. The negative pressure draws the brewed coffee back to the first tank, which contains a filter. The coffee can then be served.