Mario Gemmellaro was born in Nicolosi in 1773 and was a scholar of natural history, physics and meteorology. He was also a famous volcanologist. His research on Etna began around 1800, probably following contact with great naturalist travellers such as Déodat de Dolomieu and Lazzaro Spallanzani. In 1804, Gemmellaro built a small house, “La Gratissima”, which later became “La Casa degli Inglesi”, at an altitude of 2942 metres above sea level. Situated on the edge of the lava of the 1787 eruption, it was the first refuge at the foot of Mount Etna to host volcano enthusiasts and scholars.
With his in-depth studies, Gemmellaro demonstrated that Mount Etna was in fact an agglomeration of volcanoes. He supported the theory that volcanoes sank under their weight when they reached a certain altitude, around 3500 metres above sea level, and was one of the first to support the origin, by collapse, of the caldera depression of the Valle del Bove.
