Lightning rod
In Europe, the lightning rod was invented by a theologian and natural scientist, Václav Prokop Diviš, between 1750 and 1754. He is the inventor of the first grounded lightning rod, which he erected on 15 July 1754 in the garden of his home in Přímětice u Znojma. It consisted of 400 sharp metal spikes attached at the top of a 42 m tall supporting pylon. The structure was fastened by three metal chains, conductively attached to the iron grounding cones buried in the packed down soil. He described his 'weather machine' in the treatise 'Descriptio machinae meteorologicae'. The original idea was to continually sap the electricity out of the clouds and so actually prevent the lightning and the storms, only in case this failed, the machine should have also been able to directly attract the lighting and channel it to the ground. He proposed his machine to be used on church towers and ships. He was sending his observations regarding the machine operation to Jan Antonín Scrinci, the physics professor at the Charles University in Prague, who published them in 'Prager Postzeitungen', 'Brünner Intelligenz-Zettel' and in 'Stuttgartisches Journal'. The machine is also mentioned by Leonhard Euler in 'Lettres à une Princesse d' Allemagne'. In 1755 Diviš asked the Emperor Ferdinand I of Austria to let him build more machines on several places for the welfare of the people. The emperor let the mathematicians in Vienna judge the proposal, but they refused it. Abbé Marci, court mathematician and Diviš' friend commented: 'Blasphemant, quae ignorant' (condemning what they do not know). In 1756 the machine was damaged by wind and then rebuilt, and then on 10 March 1760, angry villagers of Přímětice tore down the structure, blaming Diviš for drought which struck the region that year. Later in the year, after the summer during which the thunderstorms did a lot of damage to the fields and vineyards, the people besought him to rebuild the machine, which he did in the precinct of Loucky monastery, and built another one on the top of the church tower in Přímětice.