Even the doctrine of the Divine Right of Kings, now condemned and obsolete, had a great influence and a good influence during the time it was in vogue; and it supplies a clear illustration of the power of a good idea, skillfully developed, to fulfill a given purpose, so long as its existence is necessary. Most men have a considerable amount of energy, but do not know what to do with it. Children are in the same category, except that toys have been invented for them, and parents give these toys to their children. Without toys, children find the days very long, and parents find their children very trying. The usefulness of toys seems to be mainly, not so much in giving children pleasure directly, as in supplying an outlet for their energies, both physical and mental. For what greater pleasure is there than in expending one's natural energies under pleasant conditions? Possibly, all the work that men have done in building up civilization is like the work that children have done with building blocks. Certainly there are many points of similarity. The mental efforts are similar; and, so far as we can see, the results are similar also. Toy temples have been built of building blocks, and then have been destroyed. Civilizations also have been built and then destroyed. And in the case of both the building blocks and the civilizations, the pleasure seems to come, not from the result achieved, but from an enjoyable expenditure of energy in achieving it. In both cases it has been the inventors who have pointed out the ways in which to expend the energy, and achieve the results. CHAPTER VII THE RISE OF ELECTRICITY, STEAM AND CHEMISTRY The invention of the first electrical machine was made by Otto Von Guericke, of Magdeburg, about 1670. It consisted of a sulphur ball, a stick with a point, and a linen thread "an ell or more long," hanging from the stick. The lower end of the thread being made to hang "a thumb breadth distance" from some other body, and the sulphur ball rubbed and brought near the point of the stick, the lower end of the thread moved up to the body. The ball being removed, the lower end of the thread would drop away from the body; so that by moving the ball back and forth, the lower end of the thread would be made to move back and forth simultaneously.