The story

The new machine looks still from outside. Inside, however, one part spins very fast. The woman in charge explains that this movement separates components that behave differently. Neri introduces the word ‘centrifuge’. ‘This centrifuge is called a decanter,’ Curiosone explains. ‘It lies horizontally.’ The movement helps separate the parts of the paste because they have different densities: equal-sized amounts do not all weigh the same. ‘We separate the oil from much of the other material in the paste.’ Leo would like to see the fast movement inside. Ada shows him the diagram, where arrows and colours make the step clear.

They do not need to open anything. Rumo follows the oil’s line to the marked outlet. Sami looks for another one. Different materials come out of the same paste. In the notebook, the path divides. But no arrow may disappear without an explanation.