Can't We Have Nice Things?

We build apparatus in order to show some effect we're trying to discover or measure. A good example is Faraday's motor experiment, which showed the interaction between electricity and magnetism. The apparatus has several components, but the main feature is that it makes visible an invisible force: electromagnetism. Faraday clearly had a hypothesis about the interaction between electricity and magnetism, and all science starts from a hypothesis. The next step was to show, through experiment, an effect that proved or disproved the hypothesis. This is how empiricists operate. They have a hunch, build an apparatus, run an experiment, refine the hunch, and then wash, rinse, and repeat.