This historic device stores static electricity by acting as a basic capacitor. It consists of a glass vessel coated inside and out with metal foil, where the glass serves as the dielectric and the foils act as the electrodes. While absent from practical power systems, it remains a fundamental teaching tool for demonstrating capacitance, charge storage and high-voltage electrostatic principles.
Heard on the job
We charged up the Leyden jar in the lab just to show the apprentices how much energy a simple glass dielectric can hold.
Insider tip
The exact same principles that govern this historic jar dictate insulation coordination and stray capacitance in high-voltage networks.