Page:Hamel Telegraph history 1859.djvu/39

 powerful battery of 380 pairs of plates six inches square, as with a small one, made by Selligue, of twelve copper cups with a zinc plate in each. It happened that on the 19th of August, when De la Rive was experimenting with the said large battery, to show Arago and some scientific persons of Geneva the brilliant incandescence of charcoal-points when placed in the voltaic circuit, in the open air, and also in a vacuum, I was, much against my wish, detained on Mont Blanc, at the Grands Mulets, the whole day, as well as the preceding and following night, in clouds discharging flashes of lightning.

I cannot forego stating my belief that Oersted knew of Romagnosi’s discovery, announced in 1802, which was eighteen years before the publication of his own observations. It was mentioned in Giovanni Aldini’s (the nephew of Galvani’s) book: “Essai théorique et expérimental sur le Galvanisme,” printed at Paris in 1804, and dedicated to Bonaparte, to whom, in Italy, he had had the honour to explain experiments relating to his uncle’s great discovery, He says, at page 191: “M. Romanesi,