The history of Static Devices
 
Influence Machine Using   Leyden Jars to collect charge.
 
 
 
Two brass balls hanging from insulated rods are influenced by the Leyden jars. (Principal of influence machines.) 
The positive charges move to the right because opposites attract and negatives repel. 

The Positive Leyden jar has been charged positively. The Negative Leyden jar has been charged negatively. The outsides of both Leyden jars are at earth or ground potential.
The neutralizing bar connects to both balls and the charges are aligned, one positive and one negative. 
This forces all the positive charges to go to one ball and all negative charges to the other ball. Because negatives attract the positive ball will be closest to the negative Leyden jar. 

We need to touch the positive ball to the positive Leyden jar and the negative ball to the negative Leyden jar. 
Because of static magnetism,  Energy is then needed to make the balls change places. The balls are moved into position for discharge into the respective Leyden jars.
The shorting rods then connect the positive ball to the positive Leyden jar, negative ball to negative Leyden jar.  
The ball gives up its charge to the Leyden jar because the Leyden jar has more capacity than the ball.  
The process is then started all over again. The small charges from the balls will generate a very large voltage in the Leyden jars.