As in the case of Franklin, so in that of Oersted, it required not merely scientific acumen, but a thoroughly practical mind, to trace, in the one instance, the actual connection between electricity and lightning, and in the other that between magnetism and electricity. It was in the year 1819 that Hans Oersted, now settled as a lecturer at Copenhagen, announced the result of a series of investigations which laid the foundation for the new science of electro-magnetism. He stated that he had found that if a magnetic needle, free to move like that of a compass, was brought parallel to a wire charged with electricity, it would leave its natural place and take up a new one, dependent on the position of the wire and the needle relative to each other. If the needle, he said, was placed horizontally under the wire, the pole of the needle nearest the negative end of the electric battery would move westward, but, on the other hand, if the needle was placed above the wire, the same pole would move eastward. Again, if the needle was placed on the same horizontal plane as the wire, no motion would be on that plane, but the inclination would be to a vertical movement. Finally, if the wire was laid to the west of the needle, the pole nearest the negative side of the battery would be depressed, but it would be raised if the wire was placed to the east of the needle. From these observations, verified in numerous experiments, Oersted concluded that the magnetic action of the electric force moved in a circular manner around the conducting object, which he expressed in the formula that ‘the pole _above_ which the negative enters is turned to the west,’ and that ‘the pole _under_ which it enters is turned to the east.’ The discoveries of Oersted resulted in the creation of that wonderful production of modern science--the electric telegraph. A minor result, highly important as regards the erection, and still more the maintenance, of lightning conductors, was the construction of galvanometers.