152 On the Application q/' Elect rico-Magneiic 



The mechanism which I employed consists of a lever put in 

 motion, after tiie fashion of a metronom, by the alternate action 

 of two fixed electrico-magnelic cylinders, operating upon a third 

 cylinder which is moveable, and attached to the lower arm of 

 the lever, whilst the superior arm maintains a constant swinging 

 movement ; which is regulated, in the ordinary method, by a 

 metallic wheel. 



The apparatus was so disposed, that the axes of the three 

 cylinders, all perfectly equal, being situated in the same vertical 

 plane, and perpendicular to tlie axis of motion, the oscillatory 

 cylinder, by one of its extremities, alternatively came in contact 

 with, and in the direction of, the one or the other of the other 

 two cylinders, placed at the extreme limits of its movements; 

 and each time, at this very instant, the direction of the magnet- 

 izing current in its spiral was changed, the rest of the circuit 

 maintaining the same direction, so as to produce poles of the 

 same name with those in the fixed cylinders, at the two extremi- 

 ties, situated in relation with the moving cylinder. The change 

 of direction, which we have just been mentioning, is obtained 

 with the help of a piece of mechanism, on the principle of a 

 balance, and known under the name of a Basciilc, where the very 

 movement of the machine itself inverts the communications. 



It is clear that, on account of this arrangement, the middle 

 cylinder must undergo alternating agreeing influences of attrac- 

 tion and repulsion, in virtue of which the mechanism puts itself 

 in motion, to all appearance spontaneously, and so actively 

 maintains it, by the arrangement of the magnetic forces which 

 incite it, and which are sustained by the electrical currents. 



I have tried to succeed without the spiral of the middle 

 cylinder, by making the two fixed magnetized cylinders alter- 

 nately act upon it. An adhesion, however, which continued 

 after the cessation of the magnetic currents, very much dimi- 

 nished the mechanical effect ; whilst, on the other hand, in the 

 other arrangement, the adhesion not only ceased, but was con- 

 verted to a certain extent into repulsion, with a rapidity equal 

 to that of the current itself, which, scarcely for an instant inter- 

 rupted by the play of the (bascule) pendulum, precipitated 

 itself (the communication being inverted) into the spiral of the 

 middle cylinder, in a contrary way to its former direction, at 



