THE MAGNETO-ELECTRIC CURRENT. 107 



machines mij^ht be obtained. It now occurred to me to 

 see to what extent the want of synchronism in the arma- 

 tures would affect the magnitude of the current. The 

 armatures were therefore unclutched and allowed to re- 

 volve independently of each other^ in the same manner as 

 when the attempt was made to take the combined direct 

 current from the commutators. After the alternating 

 current had been transmitted through the electric lamp 

 for some time^ I was surprised to find that there was no 

 perceptible diminution in the amount of light produced 

 from the carbon points^ and that the current would fuse 

 very nearly the same quantity of iron wire as when the 

 armatures were clutched together. On examining into 

 the circumstances attending this unexpected phenomenon, 

 I first observed that, whenever the machines were stopped, 

 the pins and holes in the respective disks were exactly 

 opposite each other, and that, while the armatures were 

 revolving, the two disks could at all times be engaged and 

 disengaged with the greatest facility. Moreover, even 

 when, before starting the machine, the disks were set a 

 quarter or half a revolution out of the position in which 

 the maximum amount of current was obtained, it was 

 found that, after the armatures had been revolving for a 

 few moments, the disks resumed their normal position 

 with respect to each other (as indicated by the action of 

 the clutch) — thereby exhibiting not only the synchronous 

 rotation of the armatures, but also that the machines 

 contained a principle of self-adjustment to the position in 

 which the maximum effect of the combined current was 

 obtained. It will therefore be evident that this property 

 of the current, to maintain the synchronism of the arma- 

 tures, renders it unnecessary to employ mechanical gear- 

 ing of any kind for that purpose. 



Proceeding further in this investigation, I found that. 



