Overview: Jethro Tull, a sick English lawyer, recuperates sipping wine and contributes the hoe to help fix farming problems. Farm production is not going so well in France, either. François Quesnay (doctor of King Louis XV's mistress) suggests a solution based on his complete misunderstanding of English farming techniques. Laissez-faire was his erroneous idea. It also got the people to demand social laissez-faire. His inciting the public's rebellion against the monarchy led to France's invasion of Geneva. The French Revolution led to personal exploration of the senses. Berlin doctor Müller reasoned that each sense does a different job and the nervous system analyses what the senses are telling one. Helmholtz's pupil, Hertz, discovered that sound and electricity have a wave-like nature in common. Guglielmo Marconi takes this a step further by sending and receiving signals very long distances across the earth. The BBC realised that the radio waves were reflected by the ionosphere, and Hess was the first to suggest that the ionization was due to "Hess rays" later related to solar activity. But World War II started and adding machines were needed to aim artillery, so digital computing was invented. Thus was enabled the GPS which tells travelers their "Routes".