End of the 18th Century. Discovery of the electrical nature of lightning and the possibility of avoiding its damages by giving the lightning current a path to ground. This led to the installation of air terminals, down-conductors and earthing on the highest and most important existing buildings, thus avoiding many of the personal and economical damages caused by fires and breaks due to lightning.

Lightning protection systems shall work correctly for many years.  Therefore it is essential to assure the immutability of their components under different environments and extreme conditions.