The chain of events that led to the invention of the electron microscope is an interesting story by itself. This chain has a common theme, namely electrons, and its first link is a natural phenomenon: lightning.

A flash of lightning generates a stream of electrons with a potential energy difference of 100 to 200 megavolts between clouds acting as electrodes, Benjamin Franklin envisioned this as a source of energy and tried to snatch electricity from the skies, but this proved to be too dangerous.

At the beginning of the century, lightning was a problem for electrical utilities because it produced surges that disrupted the steady flow of electricity along high tension lines. For this reason, in 1929 a high tension laboratory was founded in Germany with the sole aim of finding a way to test electrical transmission lines so as to make them capable of withstanding the lightning surges.