The machines used in the early manufacture of carbonated waters in Europe consisted of a large wooden cylinder, bound with strong iron hoops, enclosing an agitator to generate the gas. The gas passed into a gasometer, and the force pump, was next employed to compress into a cylinder the quantity of gas required to carbonate the liquid. This system was called the "Geneva" system, and is partially in use yet in Europe. The contents of a cylinder after being impregnated with gas is drawn off by the bottler before the operation can be repeated, and this plan of working is to-day called the "semi-continuous plan," of which we give descriptive illustrations in the next part of this Chapter.