Again, the sphere resting on its journals in the ring, as graduated to the condition of its interior combinations, represents a pure sympathetic concordant under perfect equation ready to receive the sympathetic, or to reject the non-sympathetic. If a pure sympathetic chord is transmitted coincident to its full combination, the sphere will remain quiescent; but if a transmission of discordance is brought to bear upon it, its sympathetic conditions become repellent to this discordance.... Keely. Hertz in his conjectures that a knowledge of the structure of ether should unveil the essence of matter itself, and of its inherent properties, weight and inertia, is treading the path that leads to this knowledge. Professor Fitzgerald says:--"Ether must be the means by which electric and magnetic forces exist, it should explain chemical actions, and if possible gravity." The law of sympathetic vibration explains chemical affinities as a sympathetic attractive, but inherent, force; in short, as gravity. This opens up too wide a territory even but to peer into in the dawning light of Keely's system of vibratory physics. The boundary line is crossed, and the crowds of researchers in electro-magnetism are full of ardour. Hertz constructed a circuit, whose period of vibration for electric currents was such that he was able to see sparks, due to the increased vibration, leaping across a small air-space in this resonant circuit; his experiments have proved and demonstrated the ethereal theory of electro-magnetism:--that electro-magnetic actions are due to a medium pervading all known space; while Keely's experiments have proved that all things are due to conditions of ether. Professor Fitzgerald closes one of his lectures on ether in these words:--"There are metaphysical grounds for reducing matter to motion, and potential to kinetic energy. Let us for a moment contemplate what is betokened by this theory that in electro-magnetic engines we are using as our mechanism the ether, the medium that fills all known space. It was a great step in human progress when man learnt to make material machines, when he used the elasticity of his bow, and the rigidity of his arrow to provide food and defeat his enemies. It was a great advance when he learnt to use the chemical action of fire; when he learnt to use water to float his boats, and air to drive them; when, by artificial selection, he provided himself with food and domestic animals. For two hundred years he has made heat his slave to drive his machinery. Fire, water, earth, and air have long been his slaves, but it is only within the last few years that man has won the battle lost by the giants of old, has snatched the thunderbolt from Jove himself, and enslaved the all-pervading ether."