Kelvin water dropper

The Kelvin water dropper, invented by Scottish scientist William Thomson (Lord Kelvin) in 1867,^[1] is a type of electrostatic generator. Kelvin referred to the device as his water-dropping condenser. The apparatus is variously called the Kelvin hydroelectric generator, the Kelvin electrostatic generator, or Lord Kelvin's thunderstorm. The device uses falling water to generate voltage differences by electrostatic induction occurring between interconnected, oppositely charged systems. This eventually leads to an electric arc discharging in the form of a spark. It is used in physics education to demonstrate the principles of electrostatics.

^ Thomson, William (November 1867). "On a self-acting apparatus for multiplying and maintaining electric charges, with applications to the Voltaic Theory". The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. Series 4. 34 (231): 391–396. Retrieved September 1, 2015.

[Thomson-1] Thomson, William (November 1867). "On a self-acting apparatus for multiplying and maintaining electric charges, with applications to the Voltaic Theory". The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. Series 4. 34 (231): 391–396. Retrieved September 1, 2015.

[1]