The dynamo is the most prominent instance of actual mechanical utility in the field of electrical induction. It seems almost incredible that the apparently small facts discovered by Faraday, the bookbinder, the employé of Sir Humphrey Davy at weekly wages the struggling experimenter in the subtleties of an infant giant, should have produced such results within sixty years. [Footnote: Faraday was not entirely alone in his life of physical research. He was associated with Davy, and quarreled with him about the liquefaction of chlorine and other gases, and was the companion of Wallaston, Herschel, Brand, and others. In connection with Stodart, he experimented with steel, with results still considered valuable. The scientific world still speaks of his quarrel with Davy with regret, since the personalities of great men should be free from ordinary weaknesses. But Lady Davy was not a scientist, and while the brilliant young mechanic was in her husband's employment for scientific purposes she insisted upon treating him as a servant, whereat the independence of thinking which made him capable of wandering in fields unknown to conventionality and routine blazed into natural resentment. The quarrel of 1823 must have been greatly augmented, in the lady's eyes, in 1824, for in that year Faraday was made a member of the Royal Society. In his lectures and public experiments he was greatly assisted by a man now almost forgotten, an "intelligent artilleryman" named Andersen. This unknown soldier with a taste for natural science doubtless had his reward in the exquisite pleasure always derived from the personal verification of facts hitherto unknown. There is often a pecuniary reward for the servant of science. Just as often there is not, and the work done has been the same. It was on Christmas morning, 1821, that Faraday first succeeded in making a magnetic needle rotate around a wire carrying an electric current. He was the discoverer of benzole, the basis of our modern brilliant aniline dyes. In 1831 he made the discovery he had been leading to for many years--that of magneto-electric induction. All we have of electricity that is now a part of our daily life is the result of this discovery.