330 P ro f' Oersted on Electro-magnetism. [Nov. 



in the direction ^ t,p u, p v, 2cc. but always so that + e remains 

 on one, — £ on the other side of the lengthened radius. 



No one will readily believe that the effect of a force can pro- 

 ceed from the surface under a different angle from the other, 

 for suppose one to act in the direction of the long radius, and the 

 other in another direction, that which would have the advantage 

 of acting directly, would produce greater effect than the other, 

 and the conductors would repel each other. It would be almost 

 the same as supposing that one force approached more in the 

 direction of the lengthened radius than the other ; for this force 

 would resolve itself into two others, one longitudinal, and the other 

 radial ; and the latter would be stronger than the radial effect of 

 the other force. 



The only supposition then by which the electrical forces can 

 produce the described effects is, that they proceed from every 

 point in such a manner that the directions of the opposite forces are 

 separated by the lengthened radius. But in order to show it clearly 

 by a figure, let us represent only the directions according to the 

 tangent, and those of some particular points, which may be 

 exhibited as examples of what passes in others. When we con- 

 sider the effects which take place in the longitudinal directions, 

 fig. 6, where the analogous points are marked by the same letters, 

 it will be seen that the direction of — £ of a meets that of + s 

 of a'. In the same manner 4- s of c, and — £ of e' meet each other. 

 This meeting of opposite forces which ought to produce attraction, 

 occurs also in most of the points of the two peripheries, that of e 

 in relation to h, f in relation to g. It is true that the points e 

 and g, /and /*, as well as the neighbouring points, repel each 

 other ; but on account of the small number of active points and 

 the oblique direction, this effect must be much exceeded by the 

 attracting effect. 



A", fig. 6, represents the transverse section of a conductor, m 

 which the directive effect of the electricity is opposed to that of 

 A and of A". The points d and d" repel each other on account 

 of + e, and the points C and C" on account of — e. Besides this 

 there exists also here repulsion between all the points which are 

 respectively in the same situation as the points which in the first 

 case attract each other. The attracting effect which g and e," 

 /'and h" produce, as well as of the neighbouring points, is here 

 overcome by the repulsive forces, in the same way as in the pre- 

 ceding case the repulsive effect, was overcome by the attracting 

 forces.* 



Although these conclusions are expressed only as it is requi- 



* I have already given this explanation in a public lecture on Jan. 2, in this year. 

 The first Tuesday in every month I give a public lecture, in which I announce new 

 discoveries as they come to my knowledge. At the same time I demonstrate their rela- 

 tion to the system of our physical knowledge. It was in one of these lectures that I 

 explained my opinion of the cause of the attractions and repulsions of the connecting con- 

 ductor. 



