Electromagnetism

2Magnetic Forces and their Work

2.1. Introduction: Academy of Sciences

• – September 4, 1820 session:

  Mr. Arago reports on Mr. Oersted’s experiments with the reciprocal influence of galvanism and magnetism. Mr. de la Rive repeated the experiments of the Danish scientist in Geneva with complete success. Mr. Arago is instructed by the Academy to repeat these experiments before next Monday.

• – September 18, 1820 session:

  I reduced the phenomena observed by Mr. Oersted to two general facts. I showed that the current in the battery acts on the magnetic needle like that of the connective wire. I described the experiments by which I had noticed the attraction or repulsion of the entire needle magnetized by the connective wire. I described the instruments that I proposed to have built, including spirals and galvanic propellers. I announced that the latter would produce, in any case, the same effects as magnets. I then went into some detail about how I design magnets, as having to only make their properties of electric currents in planes perpendicular to their axis and on the similar currents that I admit in the terrestrial globe; as a result, I reduced all magnetic phenomena to purely electrical effects.

• – September 25, 1820 session:

  I gave more developments to this theory, and I announced a new fact, that of the attraction and repulsion of two electric currents without the intermediary of any magnet, a fact that I had observed on the spirally bent conductors. I repeated this experiment ...