Leyden Jar 5C30.10
A variety of sizes of Leyden Jar are in the Electrostatics Cabinet.
The Leyden Jar is one of the oldest pieces of apparatus for the purpose of experimental researches in electricity (c. 1746).
Connect a Leyden Jar to the Toepler-Holtz machine (please observe the usual cautions about working with the Toepler-Holtz machine, as described in its webpage.
Crank the Toepler-Holtz machine. The sparks are no longer, but are brighter, louder, and less frequent when the Toepler-Holtz machine is connected than when it is not.
Discussion: The voltage which the Toepler-Holtz machine reaches is controlled by the distance between its terminals. The amount of charge transferred per spark is set by the capacitance between the two terminals, which is greatly increased by adding the Leyden Jar.
Note: When working with the Leyden Jars it is prudent to have a shorting stick (in the background of the picture of the large Leyden Jar) in case a wire comes loose from a charged Leyden Jar. Leyden Jars sparks can be painful.