Two ‘leyden jars’
The leyden jar was the original capacitor, and used to conduct many early experiments in electricity. The device was a glass jar coated inside and out with metal. The inner coating was connected to a rod that passed through the lid and ended in a metal ball. A few leyden jars connected to each other is called a battery. It has a bigger capacity and was used to demonstrate electricity, to the public, in fysical ‘shocking’ experiments.