|
|
|
If young children are asked to invent a potato‑peeling machine they draw a‑winding tube through which a string of potatoes is seen traveling towards a simple box with the explanatory note, 'In here the potatoes are peeled.' Another tube carries the peeled potatoes away. There is nothing mysterious about the box; it just performs the potato‑peeling function. One takes it for granted that is the function of the box and that somehow the function gets carried out. In some of the inventions the potatoes are then carried to a metal grid through which they are forced in order to make chips. The making of the chips is not taken for granted but explained, because it is explicable.
If you put water instead of oil into a frying pan you would not expect to be able to fry chips. If you were to use fat or oil you would get some ordinary chips. If you add a little water to the oil before you put the pan on the fire, then the temperature of the oil will rise more slowly and the chips will be soft on the inside and crisp on the outside ‑ much more so than if only the oil had been used. The nature of the system determines what happens.