At www.thunderbolts.info/wp/2017/06/19/history-of-electric-comet-theory-an-… … by Hannes Tager, is an enlightening piece of research as it lists a number of scientists that in the 17th and 18th centuries were theorising about electricity in the solar system and its bodies. These include William Gilbert (1544-1603), Otto von Guericke (1602-1686), Thomas Gray (who died in 1736) and Hugh Hamilton (1727-1805). The latter was a mathematician, natural philosopher, and at the same time a Church of Ireland Bishop of Ossory in Dublin. In 1767 he described the aurora borealis and the tails of comets as electric phenomena. Andrew Oliver (1731-1799) wrote an essay on comets and Comte de Lucepede (1756-1825) considered electricity was concentrated deep below Earth's surface and was responsible for volcanoes and earthquakes. He also thought this electricity was responsible for the separation of Spain from Africa and the opening of the Channel separating France from England.