54 On the Direct Conversion of Dynamic Force into Electricity. 



velocity, can only remain constant (its potential may be sup- 

 posed indefinitely low). 



It is therefore clear that, after the first inductive impulse has 

 been given by the presence of the separate helix, the latter may 

 be removed without appreciably affecting the result,, the main- 

 tenance of the current being due to the dynamic force employed 

 in effecting rotation, or to the inductive influence upon each 

 other of the portions of the circuit in relative motion. 



If a core of soft iron were supposed introduced into the helix 

 S, and on rotating the disk a magnet were only momentarily 

 approached (thus imparting by induction a slight polarity to 

 the iron core), it is clear that the velocity of rotation necessary 

 to maintain a current of given intensity would be much reduced; 

 for the iron core, becoming magnetic under the influence of the 

 current circulating in the surrounding helix, would thus contri- 

 bute to the effects without adding to the resistance of the circuit, 

 on the amount of wdiich, cceteris paribus, the intensity of the 

 current depends. 



The following principle serves further to elucidate the sub- 

 ject. On the rotation of any machine by the influence of elec- 

 tricity, the motive current is lowered in intensity by the induc- 

 tive action of the moving parts of the machine; but by causing 

 the rotation to take place by the use of force in the opposite di- 

 rection, the intensity of the original current is, conversely, aug- 

 mented ; or, as explained by the law of the conservation of force, 

 the electric current in effecting the rotation of the machine is 

 reduced in intensity by an amount which is represented by the 

 portion converted into dynamic energy, and on driving the ma- 

 chine in the opposite direction the intensity of the original cur- 

 rent is raised by an amount which is the equivalent of the 

 mechanical energy employed. 



The apparatus described is in principle clearly an electric 

 motor ; i. e. a current supposed to traverse the circuit made up 

 of the helix and radius of disk would tend to effect the rotation 

 of the latter; therefore by the principle just stated, if the appa- 

 ratus be caused to rotate in a suitable direction, a current in- 

 troduced into its circuit by induction or otherwise would be 

 raised to an intensity dependent on the dynamic force employed 

 in effecting rotation. 



If no limit be assigned to the velocity of rotation which could 

 be imparted, it follows as a logical fact that the circuit could be 

 fused from the relative motion of its parts without friction. 



The apparatus consisting in principle of a simple circuit, one 

 portion of which is put in motion, illustrates, as it seems to me, 

 in a striking manner, from its directness and simplicity, the 

 conversion of dynamic energy into those forms of molecular 

 motion termed electricity and heat. 



