Copper balloon. Coloured historical artwork of visitors admiring a hydrogen-filled copper balloon built by the Frenchman M. Marey Monge. This balloon was made of soldered copper sheets 1.3 millimetres thick. It was about 10 metres in diameter and weighed 360 kilograms. It was constructed in 1844 to prevent the destruction of crops by hail during thunderstorms. The balloon was to be flown from a copper wire in order, it was hoped, to conduct electricity from the clouds, and so prevent hail. Unfortunately, the plan was unsuccessful. Metal balloons had first been proposed in 1760 and the first example was made in 1784. Taken from a book published in 1860.