"Great progress has been made in electrical science, chiefly in Germany, by cultivators of the theory of action at a distance. The valuable electrical measurements of W. Weber are interpreted by him according to this theory, and the electromagnetic speculation which was originated by Gauss, and carried on by Weber, Riemann, F. and C. Neumann, Lorenz, etc. , is founded on the theory of action at a distance, but depending either directly on the relative velocity of the particles, or on the gradual propagation of something, whether potential or force, from the one particle to the other. The great success which these eminent men have attained in the application of mathematics to electrical phenomena, gives, as is natural, additional weight to their theoretical speculations, so that those who, as students of electricity, turn to them as the greatest authorities in mathematical electricity, would probably imbibe, along with their mathematical methods, their physical hypothesis. These physical hypotheses, however, are entirely alien from the way of looking at things which I adopt, and one object which I have in view is that some of those who wish to study electricity may, by reading this treatise, come to see that there is another way of treating the subject, which is no less fitted to explain the phenomena, and which, though in some parts it may appear less definite, corresponds, as I think, more faithfuHy with our actual knowledge, both in what it affirms and in what it leaves undecided.

"Great progress has been made in electrical science, chiefly in Germany, by cultivators of the theory of action at a distance. The valuable electrical measurements of W. Weber are interpreted by him according to this theory, and the electromagnetic speculation which was originated by Gauss, and carried on by Weber, Riemann, F. and C. Neumann, Lorenz, etc. , is founded on the theory of action at a distance, but depending either directly on the relative velocity of the particles, or on the gradual propagation of something, whether potential or force, from the one particle to the other. The great success which these eminent men have attained in the application of mathematics to electrical phenomena, gives, as is natural, additional weight to their theoretical speculations, so that those who, as students of electricity, turn to them as the greatest authorities in mathematical electricity, would probably imbibe, along with their mathematical methods, their physical hypothesis. These physical hypotheses, however, are entirely alien from the way of looking at things which I adopt, and one object which I have in view is that some of those who wish to study electricity may, by reading this treatise, come to see that there is another way of treating the subject, which is no less fitted to explain the phenomena, and which, though in some parts it may appear less definite, corresponds, as I think, more faithfuHy with our actual knowledge, both in what it affirms and in what it leaves undecided.

Weber's Planetary Model of the Atom Bekannt ist Wilhelm Weber zusammen mit Karl Friedrich Gauss fur die Schaffung der absoluten Masssysteme, Grundlage fur die heutigen SI-Einheiten. Webers Atommodell, entstanden um 1860 und in der physikhistorischen Literatur kaum bekannt, wird hier prasentiert von Andre Koch Torres Assis, Professor an der brasilianischen Universitat Campinas, und vom Institut fur Geschichte der Naturwissenschaften der Universitat Hamburg, von Privatdozent Dr. Karl Heinrich Wiederkehr, Studiendirektor im Ruhestand, und von Prof. Dr. Gudrun Wolfschmidt. Mit dem Triumph der Feldphysik und Nahwirkungstheorie (Faraday, Maxwell, Heinrich Hertz) legte man allzu schnell die altere Elektrodynamik als uberholte Fernwirkungstheorie ad acta. Erst Ende des 19. Jahrhunderts setzte sich der Gedanke einer substantiellen atomistischen Struktur der Elektrizitat durch (H.A. Lorentz, J.J. Thomson). Auf der Grundlage der Ampereschen Hypothese der Molekularstrome kreisen in Webers Atommodell elektrische Teilchen mit elektrischer Ladung und sehr kleiner Masse um ein ponderables Atom oder Molekul, das ebenfalls elektrische Ladung tragt. Diese kreisenden Teilchen erregen nach Weber im Ather Lichtwellen von gleicher Frequenz. Die Ahnlichkeit mit dem Bohrschen Atommodell - sieht man von den Quantenbedingungen und Quantensprungen ab - ist verbluffend. Energetische Betrachtungen bei der Ausstrahlung der Lichtwellen machte Weber allerdings noch nicht. Bei der Begrundung der Metallelektronik ging Weber ebenfalls von den Ampereschen Molekularstromen aus. Wird an dem Leiter Spannung angelegt, erfolgen Wurfbewegungen elektrischer Teilchen, die so von der Wirkungssphare eines ponderablen Atoms in die Wirkungssphare eines benachbarten Atoms gelangen. Auf diese Ideen aufbauend schufen dann Riecke, Drude und H.A. Lorentz die klassische Elektronentheorie der Metalle. Sommerfeld nahm unter Benutzung der inzwischen entwickelten Quantentheorie diese Idee wieder auf und die Festkorperp