TO THE MOVEMENT OF MACHINES. 507 



points, and is not at all affected by their relative velocity. The inversion 

 of the poles being effected instantaneously, we should thus have a velocity 

 infinitely accelerated. Now a system moving round an axis, and capable 

 of a continuous circular motion, is that which is alone susceptible of such 

 a velocity. It cannot become uniform, unless some resisting element, or 

 some other action depending on the velocity, is introduced into the 

 system. Putting aside the application to practical use which has to be 

 made of such an apparatus, the obstacles to be overcome, inseparable from 

 the system, consist only in the friction of the pivots in the sockets, and 

 in the resistance of the air. As to the former, repeated experiments 

 have proved that the friction is independent of the rapidity of rotation, 

 at least within the limits of experiment ; this resistance, therefore, can 

 in no way contribute to render the accelerated motion uniform. It 

 is in fact the resistance of the air which will act to produce this effect. 

 Although it might be reduced at pleasure, principally by giving a suitable 

 form to the rotatory system, it would not be entirely annihilated. But it 

 will be allowed, that we should have reason to be well satisfied with the me- 

 chanical effect of magnetism, if this were the onlj' cause which tended to 

 reduce the accelei'ated movement to a uniform movement. The limits of 

 such a uniform velocity must be very distant. I do not speak, of the great 

 simplicity of a magnetic machine with a continuous circular motion, of 

 the advantages of construction which are gained by being able to trans- 

 form with ease this motion to any other which the working machine 

 may require. These considerations had strongly impressed my mind, even 

 whilst the means of execution were still unknown to me, but I always 

 kept in sight the practical application, and the object appeared too 

 important for me to exhaust my powers in the construction of see-saw 

 toys, which might claim the honour of being placed in the rank with the 

 electric chime relatively to their effect, and still more relatively to the 

 tinkling with which they are accompanied. 



4. 

 Fig. 1 . of the annexed plate represents the magnetic apparatus of eight 

 bars, arranged symmetrically upon a disc moveable round the axis A, and 

 of eightfixedbars similarly arranged uponafixed platform. The arrange^ 

 ment of the bars admits of the greatest variety, provided it be exactly 

 symmetrical, and that it allow the poles to approach each other as nearlj' 

 as possible. To prevent the action being too oblique, — since the centre 

 of magnetic gravity is probably at some distance from the extremity, as 

 in the ordinary magnetic bars, — it is preferable to make this arrangement 

 so that the axes of the cylindrical bars shall be situated rectangularly, 

 and not parallel, as in the figure. It must be further observed, that there 

 will be some difficulty in forgiiig bars of considerable dimensions into 

 the horseshoe form, so that the axes of the branches be situated exactly 



